Supraventricular Tachycardia

AP19‐­00040

“Tracked elusive signal”—WPW syndrome due to middle cardiac vein accessory pathway

Nishan De Vas Goonewardane, Suresh Kottegoda

Sri Jayewardenepura General Hospital, Sri Lanka

Introduction:

18 year old girl was referred for recurrent palpitations on exertion. Surface ECG revealed pre‐­excitation syndrome with possible right sided accessory pathway. Electrophysiology (EP) study was planned after baseline evaluation. Routine investigations including 2D ECHO was normal.

Methods:

Right femoral vein access achieved. Three catheters were placed in His bundle, Coronary sinus and right ventricle. SVT study revealed an accessory pathway and orthodromic atrioventricular reciprocating tachycardia (AVRT). Ventricular–Atrial (VA) as well as high right atrial (HRA) pacing did show an accessory pathway activation without a decrement property. Extensive mapping in AV junction was in vain and fortunately a fusion of atrioventricular conduction with an elusive high amplitude accessory pathway potential was obtained in the coronary vein approximately 5‐­10 mm from the coronary sinus ostium in an unstable catheter position. Intracardiac electrocardiogram of SVT showed the earliest atrial activation at CS7‐­8.

Result:

Ablation catheter was vigilantly placed in the exact position with difficulty. The delta wave disappeared and the accessory pathway conduction was interrupted at 5 seconds after initiation of RF ablation (30 W at 55 Celsius). Post‐­op imaging did not reveal any pericardial effusions and delta wave completely disappeared in surface ECG as well.

Conclusion:

25% of accessory pathways are said to be placed in postero‐­septal area. Extension in to coronary sinus and middle cardiac vein is a known but rare phenomenon. The so called pathway potential which was seen as a clear sharp spike in this case is quite difficult to demonstrate. Damage to venous system, adjacent structures (RCA ostium, compact AV node) should be born in mind. Coronary vein anomalies should be excluded (Eg: diverticulam).

Intra‐­cardiac mapping

Accessory pathway potential seen on ablation catheter

Change of surface ECG polarity and pre excitation with ablation

AP19‐­00048

A safe and simple approach to avoid fast junctional rhythm during ablation in patients with atrioventricular nodal reentrant tachycardia

Kimikazu Banba, Motomi Tachibana, Masanori Yamamoto, Kensuke matsumoto, Shun Higashikawa

The Sakakibara heart institute of Okayama, Japan

Introduction:

Fast junctional rhythm (JR) during slow pathway modification for atrioventricular nodal reentrant tachycardia (AVNRT) is a predictor of serious atrioventricular block. This study investigated the boundary to avoid fast JR during ablation with 3D electroanatomical mapping in AVNRT patients.

Methods:

Participants were 129 consecutive patients with common AVNRT who received anatomical ablation to an antegrade slow pathway at our institution between August 2013 and March 2019. Successfully ablated sites with JR were evaluated in terms of distances and angles in the left and right anterior oblique views (LAO and RAO, respectively) to the proximal His bundle (His) site using 3D mapping. We divided JR by heart rate: JR1 ≥150 bpm and JR2 < 150 bpm.

Result:

Average age was 61 ± 16 years; 41.1% of patients were male. The distance from the most proximal His to the JR1 and JR2 site was not significantly different (11.9 ± 4.4 vs 10.7 ± 4.5 mm, P = .24). JR1 predominantly appeared closer to the left ventricle than JR2 in LAO (110.5 ± 19.1 vs 77.5 ± 18.6°, P < .01), and was more posterior from the proximal His in RAO (30.8% vs 6.8%, P < .01). The vertical line drawn down from the proximal His in the LAO view was a good indicator of JR1 appearance (sensitivity and specificity 84.6% and 81.6%, respectively).

Conclusion:

The vertical line drawn down from the proximal His in the LAO view can be employed as a boundary to avoid fast JR during ablation in AVNRT.

AP19‐­00055

Clinical spectrum of Wolff‐­Parkinson‐­White syndrome in Ebstein anomaly: Insights into electrophysiology and catheter ablation

Saruul Tseveendee, Uhm Jaeseon, Dosjan Edilkhan, Kim Young Hoon, Chun Hwang

Third State Hospital, Mongolia

Introduction:

Ebstein anomaly is an uncommon congenital abnormality that involves the right‐­sided cardiac chambers and is primarily due to failure of delamination of the tricuspid valve. This results in inferior displacement of the tricuspid valve and tricuspid regurgitation (TR), which are associated with the degree of atrialization of the right ventricle (RV).¹ A significant number of patients with Ebstein anomaly develop cardiac arrhythmias during their lifetime including supraventricular tachycardia (SVT), atrial fibrillation and flutter, and ventricular tachycardia.² The most prevalent arrhythmias in patients with Ebstein anomaly were atrioventricular reentrant tachycardia (AVRT) due to Wolff‐­Parkinson‐­White (WPW) syndrome. Most of the accessory pathways (APs) were right‐­sided.³

Methods:

A 22‐­year‐­old man with Ebstein anomaly associated with severe TR and RV failure underwent tricuspid valve replacement (TVR) with a bileaflet mechanical valve at age 16 years. He had WPW syndrome consistent with right posterior AP with antidromic tachycardia before the TVR. Surgical ablation for WPW was not performed during the surgery. Owing to early recurrences of tachycardia, the patient underwent a first catheter ablation attempt during post‐­operative recovery; however, it failed to eliminate AP. Thereafter, he experienced increasing burden from recurrent refractory wide QRS complex tachycardia despite oral administration of amiodarone 200 mg twice a day and required emergency cardioversion to restore hemodynamic stability. Transesophageal echocardiography confirmed the presence of thrombus in the posterior leaflets of the mechanical valve.

Result:

Once the venous accesses were completed, he was properly anticoagulated with intravenous infusion of heparin. The CS catheter placement was challenging because the CS ostium was blocked by the mechanical tricuspid valve. Only small 6‐­F catheters were used to cross the mechanical valve and the CS was successfully cannulated. The His bundle location was confirmed below the mechanical tricuspid valve. Mapping and ablation were performed using a 7‐­F open irrigation ablation catheter (CoolFlex; St Jude Medical, Minnetonka, MN, USA). Supra‐­tricuspid valve mapping confirmed that the AP was located below the mechanical valve. To map and ablate the AP, the ablation catheter was placed across the mechanical valve and oriented posteriorly, avoiding direct contact with the mechanical valve leaflets or ring. The AP potential was recorded 5‐­6 mm below the tricuspid valve ring at the atrialized RV and the ablation at the site using 35 W with an irrigation flow of 30 mL/min eliminated AP conduction.

Conclusion:

In patients with Ebstein anomaly and WPW syndrome, 3‐­D high‐­density electroanatomical mapping and catheter ablation across the mechanical tricuspid valve are feasible and useful.

AP19‐­00056

A case of atrial tachycardia that was difficult to diagnose from body surface electrocardiogram and intracardiac electrocardiogram of pacemaker

Yusuke Sakamoto

Tosei General Hospital, Japan

Introduction:

The case is a 54‐­year‐­old woman.

Methods:

A complete atrioventricular block was pointed out at a medical checkup in 2017. Grandmother, mother and maternal uncle also had pacemaker surgery history. There were no basic heart disease. Sick sinus syndrome was also found, and pacemaker implantation was performed. Six months after indwelling, atrial tachycardia was found and frequency gradually increased, so catheter ablation was performed in 2019. Preoperatively, the atrial wave cycle length around 200 milliseconds and 400 milliseconds were confirmed by body surface electrocardiogram and intracardiac electrocardiogram of pacemaker.

Result:

In the intracardiac electrocardiogram at the start of ablation, the AT with cycle of 200 milliseconds was sustained. There were inter atrial conduction delay and intermittent 2:1 LA to RA conduction block. In the voltage mapping of the left atrium, there was low voltage zone (LVZ) only on the anterior wall. Fragment potential was found between the LVZ of the anterior wall and mitral annulus, and tachycardia was terminated at this site by the catheter contacts, and it became impossible to induce by ablation. After RF application, she can live without recurrence of AT.

Conclusion:

In this case, although there was no basic heart disease, in addition to the atrioventricular conduction block and sick sinus syndrome, inter atrial conduction block was also complicated. As significant family history was also recognized, so we considered that these abnormalities were caused by progressive cardiac conduction disorder.

AP19‐­00062

Comparison of clinical and conduction parameters of atypical AVNRT and typical AVNRT

Keerthika Ravella

NIMS, India

Introduction:

Atypical AVNRT comprises a minority of cases of AVNRT. The “splitters” have sub‐­ grouped atypical AVNRT as “fast‐­slow”, “slow‐­slow”, “slow‐­intermediate”, etc; We used the ‘lumpers’ approach and considered atypical AVNRT as one group. We assessed the prevalence of atypical AVNRT and compared its demographics and EP parameters with those of typical AVNRT.

Methods:

This was a retrospective study of patients with AVNRT, who were admitted and underwent EP study over the last 10 years. AVNRT was considered atypical when the HA time exceeded 100 milliseconds. Out of the 1015 patients who were admitted with a possible diagnosis of AVNRT, 50 (5%) had atypical AVNRT (Group A), and the other 965 (95%) patients had typical AVNRT (Group T). We compared Group A with 300 patients from Group T. —The clinical parameters compared were age at presentation and gender. —The EP parameters compared were tachycardia rate, AV conduction features (AH jump, Wenckebach point, AVNERP), VA conduction features (VAERP), mode of tachycardia initiation/termination and associated arrhythmias.

Result:

The tachycardia rate was lower in Group A. Tachycardia initiation by AES was always seen in Group T; by VES, this was seen only in Group A. Tachycardia termination by AES was more common in Group T; while termination by VES was more common in Group A. With respect to the remaining parameters, there was no significant difference between the two groups apart from a marginal difference in the magnitude of the AH jump.

Conclusion:

There are subtle differences between Typical and Atypical AVNRT in the tachycardia rate mode of initiation and termination.

Parameter	Group A	Group T	P value
Age (years)	46 ± 15	47 ± 15	.47#
Gender (male/female)	17/33	117/183	.5*
Tachycardia rate (beats per minute)	175 ± 20	191 ± 26	<.0001#
AH jump (msec)	73 ± 18	68 ± 14	.02#
AV Wenckebach point (ms)	303 ± 37	313 ± 45	.17#
AVNERP (ms)	260 ± 30	256 ± 30	.35#
VAERP (ms)	270 ± 31	269 ± 36	.82#
Tachycardia initiation by AES	36 (72%)	300 (100%)	<.0001*
Tachycardia initiation by VES	14 (28%)	0	<.0001*
Tachycardia termination by AES	30 (60%)	262 (89%)	<.0001*
Tachycardia termination by VES	20 (40%)	38 (11%)	<.0001*
Associated arrhythmias (Yes/No)	47/3	284/16	.85*

AP19‐­00063

Automaticity of MAHAIM masquerading CPVT

Keerthika Ravella

NIMS, India

Introduction:

22 year old woman. 1st pregnancy, 3rd trimester. Recurrent palpitations, giddiness, near‐­ syncope. Examination normal, except for ectopics. Echocardiogram normal. PVCs with varying coupling interval. 24 hour Holter‐­ Multiple unifocal PVCs, ventricular couplets, MMNSVTs Started on propranolol 20 mg BDEctopics persisted. Holter repeated after 1 week‐­ similar as before. Amiodarone added. Delivery by Caesarian section 1 week later. Post‐­partum period uneventful. Holter 1 month later‐­ similar as before

Methods:

Taken up for EP study after stopping drugs for 2 weeks‐­comment. ‘Unifocal’ PVCs with varying coupling intervals; no common basic interval, hence not a parasystole. The PVCs have LBBB morphology, +ve in L1, more +ve in L II than III. Atrial pacing…interpret. The LBBB induced by RA pacing is identical to the PVCs. Likely to be spontaneous automaticity of a Mahaim‐­like accessory pathway. Any further insight? RA pacing, with LBBB pattern of ventricular conduction with small r in V1 1 ‘PVC’, the APERP is reached. Decapolar catheter placed across the His‐­RB region. RA pacing. Reversal of His‐­RB activation with preexcitation, 1 ‘PVC’ which has an identical QRS. No ‘M’ potential found along the tricuspid annulus. The RV was mapped. The best early activation obtained…

Result:

RF energy‐­ AP eliminated, RBBB seen.

Conclusion:

Right free wall atriofascicular Mahaim pathway inserting into RBB Frequent automaticity from ventricular insertion site producing symptomatic ‘VT’ Successful RF ablation with resultant RBBB

AP19‐­00073

Left inferior lateral ablation of typical AVNRT (left sided AVNRT)

Ramdeo Yadave

Batra Hospital, India

Introduction:

Forty nine year old female presented with recurrent palpitations for 10 years duration. ECG during palpitation suggestive of AVNRT with baseline ECG without any preexcitation. Echo showed structurally and functionally normal heart. EP Study done which confirmed AVNRT after excluding other mechanism of SVT. Tried to ablate inferior –posterior right septum but failed to ablate and so patient was put on Metoprolol 50 mg BD but after few months AVNRT recurred even on beta‐­ blocker. Therefore taken up for repeat procedure and 3D Mapping Navix was used.

Methods:

First I tried to ablate on the right side of Inferior triangle of Koch but tachycardia was remain inducible even good number of junctional beats are coming

Result:

When failed to ablate on the right side then I used 3D NavX system mapping and by transseptal route to map and ablate the tachycardia. On the left lateral Mitral annulus RFA was started by seeing the slow pathway potential and with single RF application several number of junctional beat recorded and RFA given for 70 sec with further no AVNRT was inducible. Over more than one year of follow up no tachycardia was inducible.

Conclusion:

The left sided variety of Typical Slow –Fast AVNRT is very rare. This is first case for me where I did RF ablation from left inferolateral part of Mitral annulus when failed to ablate from right side at two attempt with frequent junctional beats. Over more than one year of follow up there is on recurrence of tachycardia.

AP19‐­00074

Narrow QRS tachycardia with VA block with varying VV interval

Ramdeo Yadave

Batra Hospital, India

Introduction:

Forty one year old male presented with recurrent paroxysmal palpitation for 7 months duration. Baseline ECG showed no pre‐­excitation. ECG during palpitations showed regular narrow QRS tachycardia with retrograde P in the tail of QRS suggestive of AVNRT. Echo showed structurally and functionally normal heart. Taken up for EPS and RF ablation.

Methods:

On v Pacing VA conduction was concentric and decremental. On A pacing irregular narrow QRS tachycradia induced with VA block with variation in VV intervals.

Result:

Differential diagnosis of this disorder includes: automatic junctional tachycardia (AJT), atrioventricular nodal reentry (AVNRT) with final upper common pathway block, concealed nodofascicular [ventricular) pathway (NF), or intra‐­Hisian reentry. Since VV interval varying so Nodofascicular pathway excluded. So either it is AVNRT or JT.

Conclusion:

This irregular narrow QRS tachycardia with VA block suggest automatic Junctional tachycardia but This tachycardia was induced by programme electrical stimulation and terminated by overdrive ventricular pacing. On V pacing in Sinus Rhythm showed VA conduction concentric and Decremental suggest retrograde conduction through AV node. On A pacing dual AV nodal physiology present and leads to onset of this Irregular Tachycardia with VV interval from 330 to 400 milliseconds. The above features suggest reentry as the cause of irregular tachycardia and VV variation is due to variation in conduction in the AV nodal reentrant Circuit. Since this tachycardia was non inducible after slow pathway ablation proves to be AVNRT.

AP19‐­00082

LSI to assess the adequacy of lesion formation for typical atrial flutter

Sri Sundaram, Dan Alyesh, Ganesh Venkataraman, Austin Stucky, Nate Mullins, William Choe

South Denver Cardiology, USA

Introduction:

The purpose is to describe the use of lesion index (LSI) to assess the adequacy of lesion formation in ablation of typical atrial flutter (AFL). The appropriate LSI value for the CTI has not been established. LSI is calculated by the formula: LSI = CF (g) × Current (mA) × Time (sec).

Methods:

18 patients with a history of AFL in NSR at the time of presentation, underwent ablation of the CTI. Pacing was performed from the distal pole of the ablation catheter during ablation at 2× diastolic threshold. Ablation lesions were delivered until pacing no longer captured and the corresponding LSI value was noted. Ablations lesions were delivered until Bi‐­directional block was achieved in all patients.

Result:

In the proximal 1/3 of the isthmus, the LSI was 4.71 (+0.91) and the RF time was 28.7(+17.8) seconds, middle 1/3 LSI was 5.40 (+0.94) and the RF time was 26.6 (+17.4), distal 1/3 LSI was 4.62 (+0.92) seconds and RF time was 22.1 (+10.7) seconds. In comparison to the other locations, the middle 1/3 of the CTI required a higher LSI value (P = .0004) to achieve an adequate lesion.

Conclusion:

Anatomic studies have shown that the middle 1/3 of the CTI is thicker than the proximal and distal 1/3. The LSI value needed to achieve a lesion varies according to the location within the CTI with the thickest part of the CTI requiring a higher LSI value and increased number of ablation lesions.

AP19‐­00086

Successful ablation of atypical atrial flutter originating in left atrium with diffuse low‐­ voltage activity by using an ultra‐­high density mapping system

Jan‐Yow Chen, Kuan‐Cheng Chang

China Medical University Hospital, Taiwan

Introduction:

Ablation therapy for atypical left atrial flutter is a challenge and time‐­consuming procedure because of anatomical abnormalities, variable reentrant circuit, and difficulty in identifying the ablation target. A new ultra‐­high density mapping system (Rhythmia) has reported enabling fast acquisition of cardiac electrocardiograms and low voltage signals might be beneficial for mapping and ablation of atypical atrial flutter.

Methods:

A 52‐­year‐­old female experienced palpitation with dyspnea for one month. ECG showed atrial flutter with 4:1 atrioventricular conduction. The amplitude of the P waves was significantly low in the 12 leads of surface ECG. An ultra‐­high density mapping system was used for mapping of the atrial flutter.

Result:

Diffused low‐­voltage was detected in the left atrium (LA). The activation mapping demonstrated the atrial flutter wavelets propagated throughout the anterior wall then the posterior wall of LA. A slow conductive isthmus of the atrial flutter reentry circuit located in the anterolateral wall of LA was identified by the ultra‐­high density mapping system. Successful ablation was achieved by delivery of radiofrequency energy over the slow conductive isthmus.

Conclusion:

The ultra‐­high density mapping system is useful for rapidly determining the detailed reentry circuit and ablation target for atypical flutter originating in the LA with diffused low‐­voltage activity.

AP19‐­00113

Procedural success and long‐­term outcome of CTI ablation targeted with maximum voltage‐­ guided approach: preliminary results from LEONARDO registry

Giampiero Maglia, Ermenegildo De Ruvo, Francesco Pentimalli, Francesco Solimene, Leonardo Calò, Tommaso Infusino, Giovanni Battista Perego, Giuseppe Stabile, Anna Rago, Corrado Tomasi, Gianluca Zingarini, Mario Matta, Carmelo La Greca, Marco Scaglione, Francesco Aperuta, Maurizio Malacrida, Roberto Verlato

A.O. Pugliese Ciaccio, Italy

Introduction:

Ablation technique targeting high‐­amplitude signals (maximum voltage guided – MVG ‐­) on the cavotricuspid isthmus (CTI) has emerged as viable alternative option compared to standard anatomical approach (ST) for the creation of bidirectional conduction block (BDB) across the isthmus but limited data are available to date. To evaluate the effectiveness of acute and long‐­term outcome of CTI ablation through MVG technique for AFL compared to standard linear (SL) lesion ablation.

Methods:

Atrial Flutter Ablation in a Real World Population (LEONARDO) is a prospective, multicenter cohort study aimed at providing an estimate of acute to long‐­term outcome in a large population of patients (pts) indicated for AFL ablation. Recurrence of AFL were retrieved at 12‐­month follow‐­up. Complete BDB was defined by agreement with the presence of widely split double potentials (DP) along the ablation line and assessment of the atrial activation sequence (AAS). For MVG technique the ablation catheter was positioned at the site of maximum local electrogram voltage.

Result:

Two‐­hundred fifteen consecutive pts were included (mean age 68 years, 73% male). A median of 4 [2‐­6] ablation lesions were required. Median follow‐­up was 359 [192‐­443] days. Complete BDB was achieved in 175 (81.4%) pts (9 pts had DP only criterion, 30 pts had AAS only criterion whereas in 1 pt we failed to reach a BDB). In the 106 pts with complete data at 1‐­year follow‐­up, 10 (9.4%) had a recurrence of AFL. 171 pts (79%) underwent a SL ablation whereas 44 pts (21%) were treated by MVG approach. The median number of lesions/pt was significantly lower in the group of pts targeted with MVG compared to the SL approach (3 [2‐­4] vs 4[2‐­8], P < .01), whereas no differences were found in terms of fluoroscopy time (16 [12‐­18] minutes vs 12 [7‐­22] minutes, P = NS) or proportion of pts with BDB achievement (86.4% of the cases for MVG vs 80.1% of the cases for ST, P = NS). No complications were reported. AFL recurrence was comparable during follow‐­up between groups (8.3% for MVG vs 9.8% for SL ablation; P = NS).

Conclusion:

Ablation of a targeted site through MGV approach seems to be safe and effective as standard anatomical ablation technique. This strategy may avoid unnecessary ablation of the entire anatomic isthmus.

AP19‐­00114

Ablation of CTI‐­dependent flutter using a novel advanced mini‐­electrodes technology: Preliminary results from LEONARDO registry

Giampiero Maglia, Roberto Verlato, Francesco Solimene, Francesco Pentimalli, Leonardo Calò, Tommaso Infusino, Giovanni Battista Perego, Giuseppe Stabile, Anna Rago, Corrado Tomasi, Gianluca Zingarini, Chiara Devecchi, Carmelo La Greca, Marco Scaglione, Francesco Aperuta, Maurizio Malacrida, Ermenegildo De Ruvo

A.O. Pugliese Ciaccio, Italy

Introduction:

Ablation of cavotricuspid isthmus (CTI) represents the standard therapeutic approach for the creation of bidirectional conduction block (BDB) across the isthmus and the prevention of recurrences, yet recurrence of arrhythmia is common. To evaluate the acute and long‐­term outcome of CTI ablation through a novel ablation catheter equipped with three radially distributed mini‐­electrodes (ME) compared with standard ablation catheter technology (ST).

Methods:

Atrial Flutter Ablation in a Real World Population (LEONARDO) is a prospective, multicenter cohort study aimed at providing an estimate of acute to long‐­term outcome in a large population of pts indicated for AFL ablation from 2015 to 2017. The procedural endpoint was the creation of a BDB. Presence of widely split double potentials (DP) along the ablation line and assessment of the atrial activation sequence (AAS) were used as criteria for complete BDB. Recurrence of AFL and complications were assessed at 12‐­month follow‐­up.

Result:

205 consecutive pts undergoing typical AFL ablation were included (74% male, 50.6% with history of AF, median of 7 [4‐­11] ablation lesions, median ablation time of 20 [10‐­30] minutes). Complete BDB was achieved in 175 (85.4%) pts (10 pts had DP only criterion, 19 pts had AAS only criterion whereas in 1 pt we failed to reach a BDB). 15 (7.3%) pts experienced AFL recurrence during follow‐­up.

102 pts (49.8%) underwent ablation procedure with ME catheters whereas 103 (50.2%) pts were treated by ST catheters. The median number of lesions/pt was significantly lower in the ME group compared to the ST one (4 [3‐­6] vs 8.5 [6‐­12], P < .0001), whereas no differences were found in terms of fluoroscopy time (10.5 [7‐­15] minutes vs 10 [5.8 ± 15] minutes, P = NS) or ablation time (22.5 [10‐­30.5] minutes vs 18 [10‐­26] minutes, P = NS). No complications were reported. The acute procedural success was comparable between groups (81.4% vs 89.2%, P = NS) whereas the time to AFL recurrence was significantly longer among pts targeted with ME catheters (HR = 0.343; 0.12‐­0.97; log‐­rank P = .044).

Conclusion:

In our preliminary experience, the use of the ME technology seemed safe and effective. It resulted in fewer lesions/pt and a lower AFL recurrence rate at 1‐­year follow‐­up compared with ST ablation catheters.

AP19‐­00157

Intriguing rhythm in a patient with left posteroseptal accessory pathway

Suchit Majumdar

Apollo Gleneagles Hospital Kolkata, India

Introduction:

Automatic impulse formation originates in cells with spontaneous diastolic depolarization, found in the sinus node, AV node, coronary sinus ostium, and crista terminalis. Abnormal automaticity may be unmasked after ablation that injures the cell and promotes spontaneous depolarisation. Abnormal automaticity is also seen in ligament of Marshall, atrial muscular sleeves into PV. Among pathways, atriofascicular pathway (likely to show spontaneous and ablation induced automaticity due to its structure like AV nodal tissue).

Methods:

Hence we report a case of interesting wide QRS rhythm in a patient with left posteroseptal pathway.

Result:

36 years man with history of recurrent episodes of palpitations for last 10 years, increasing in frequency recently. Baseline ECG was suggestive of posteroseptal accessory pathway. EP study showed HV of 18 milliseconds. Maximal preexcitation was suggestive of left posteroseptal accessory pathway. On ventricular pacing, retrograde conduction was mixed (through pathway and node), however during induced tachycardia, earliest A was in proximal CS, and His A was late. AV Wenckebach was at 240 milliseconds. Narrow QRS tachycardia was induced easily by atrial and ventricular extra beats. Tachycardia was suggestive of orthodromic AVRT, retrograde through posteroseptal accessory pathway. Entrainment from RV apex shoed PPI‐­ TCL = 108 milliseconds and SA‐­VA = 62 milliseconds. His refractory VPC pulled A with reset of tachycardia. After terminating the induced tachycardia by burst ventricular pacing, there was a wide QRS rhythm at rate of 160 bpm was noticed instead of the expected sinus rhythm. The morphology of QRS was similar to preexcited rhythm and atrial activation which preceded the V was also same as the retrograde A activation during tachycardia. Further, there was QRS alternans and cycle length wobbling during the rhythm. During the alternans, there was alternate beats of QRS morphology same as maximal preexcitation (LV exit) and QRS morphology suggesting of posteroseptal exit into RV. There was AA wobble preceding the VV wobble. After some time, this rhythm slowed down and gave way to sinus rhythm. Transseptal access was done, and pathway was ablated successfully in left posteroseptal area. Thereafter there was no tachycardia or wide QRS rhythm induced.

Conclusion:

In this case the rhythm can be due to the following possibilities: (a) Coronary sinus automaticity (as there was fragmentation of CS potentials on ventricular burst pacing). (b) Bypass tract automaticity (catecholamine was given to induce tachycardia, and this may increase automaticity). (c) Preexcited Atrial Tachycardia from near the atrial insertion of the pathway. However spontaneous bypass tract automaticity is uncommon in nondecremental pathways, and before ablation. The QRS alternans is suggestive of pathway exit into left and right ventricle, indicating complexity of posteroseptal space or the connections of musculature in CS to both ventricles.

Wide QRS Rhythm with wobble and QRS Alternans

AP19‐­00160

Mechanism of double potentials during typical atrial flutter in a patient with atrial septal defect after surgical repair

Ching‐Yao Chou

Shing‐­Kong Memorial Hospital, Taipei, Taiwan

Introduction:

Double potentials is a common electrophysiological finding in the patients with anatomic scar and surgical scar. During mapping of tachyarrhythmia, the double potentials might mislead the interpretation of mechanism.

Methods:

We report a case of typical atrial flutter with history of surgical repair for atrial septal defect.

Result:

A 32‐­year‐­old woman was diagnosed with secundum atrial septal defect post patch closure. She had been clinically stable without medical therapy until several recent attacks of severe palpitation and hemodynamic shock. Under the impression of supraventricular tachycardia, electrophysiological study with 3‐­D anatomic mapping was performed. The tachycardia cycle length was 318 milliseconds. A rapid atrial signal with cycle length 158 milliseconds at low free wall of right atrium was found. Focal atrial tachycardia with two to one conduction to the surrounding atrial tissue was suspected. 3D electroanatomical mapping demonstrated counter‐­clockwise activation around tricuspid annulus. A conduction barrier due to previous surgical scar was localized in the right atrium free wall. The double potentials was resulted from the collision of wavefronts from posterior wall. The concealed entrainment from cavotricuspid isthmus proved the diagnosis as cavotricuspid isthmus dependent atrial flutter. After cavotricuspid isthmus ablation, tachycardia terminated and activation map in sinus rhythm also demonstrated the double potentials at the low right atrium free wall.

Conclusion:

Double potentials, a common electrophysiological finding in the patients with a surgical scar, might mislead the mechanism of arrhythmia. Careful and complete 3‐­D electroanatomic mapping is required to evaluate the underlying mechanism of double potentials and arrhythmia

AP19‐­00162

Very late recurrences (≥ 3 years) of atrioventricular nodal reentrant tachycardia: Electrophysiologic characteristics of index and repeat procedures

Chye Gen Chin, Fa‐Po Chung, Yenn‐Jiang Lin, Shih‐Lin Chang, Li‐Wei Lo, Yu‐Feng H Hu, Ming‐Hsiung Hsieh, Shih‐Ann Chen

Wanfang Hospital, Taiwan, Taiwan

Introduction:

Catheter ablation is an effective strategy for atrioventricular nodal reentrant tachycardia (AVNRT). However, the very late (>3 years) recurrences of AVNRT after initially successful ablation are not well elucidated before. We sought to explore the electrophysiologic characteristics of very late recurrence after ablation for AVNRT.

Methods:

From 1991 to 2018, a total of 3311 patients (mean age: 48.7 ± 17.4 years; 1328 male [40.1%]) receiving catheter ablation for AVNRT were investigated. Baseline characteristics, the recurrent status, and detailed electrophysiological parameters during index and repeat procedure were extracted for analysis.

Result:

After 128.7 ± 58.1 months of follow‐­up, 65 patients (2.0%) underwent repeat ablation for recurrent AVNRT, including very late recurrences in 17 (0.5%). The incidence of transient AV node injury is significantly higher in patients with late recurrences (5.9%) than those without recurrences (1.9%) but lower than those with early recurrences (12.5%, P < .001) (Table 1) In addition, patients with recurrent AVNRT undergoing repeat catheter ablation, those with late recurrences had significantly longer AH interval (99.1 ± 23.4 milliseconds vs 82.2 ± 20.4 milliseconds, P < .01) and more need of intravenous isoproterenol and/or atropine for induction (88.2% vs 62.5%, P = .03) when compared with the index procedure (Table 2)

Conclusion:

Recurrent AVNRT can occur 3 years later after initially successful ablation. Patients with late recurrence had distinct electrophysiological features from those early recurrence of AVNRT during index and repeat procedure.

TABLE 1 The comparisons of baseline and electrophysiological characteristics between patients without and with recurrent AVNRT

No recurrences (n=3246)	Recurrences (n=65)	P value
Age	48.8±17.4	43.0±15.0	.23
Sex (male, %)	1308 (40.3%)	20 (30.8%)	.12
Types of AVNRT
Typical AVNRT only	2812 (86.6%)	58 (89.2%)	.63
Atypical AVNRT only	182 (5.6%)	2 (3.1%)
Multiform AVNRT	252 (7.8%)	5 (7.7%)
AH interval (ms)	81.6±26.6	81.8±15.7	.95
Jump
Antegrade	2596 (80.0%)	55 (84.6%)	.35
Retrograde	663 (20.4%)	19 (29.2%)	.08
Antegrade conduction
AVNF 1:1 (ms)	390.4±93.0	393.2±101.0	.82
AVNF ERP (ms)	333.5±80.7	331.1±83.4	.82
AVNF FRP (ms)	413.9±78.0	417.2±80.6	.76
AVNS 1:1 (ms)	359.4±69.9	372.0±77.3	.38
AVNS ERP (ms)	284.2±57.8	296.8±72.4	.16
AVNS FRP (ms)	520.7±102.3	527.5±130.2	.74
AERP (ms)	214.0±37.8	225.2±29.5	<.03
AFRP (ms)	245.0±43.1	254.2±39.4	.13
Retrograde conduction *
AVNF 1:1 (ms)	376.2±99.1	386.6±76.3	.47
AVNF ERP (ms)	299.3±84.3	304.6±74.4	.62
AVNF FRP (ms)	372.5±69.2	374.1±68.4	.88
V ERP (ms)	220.0±28.2	222.9±27.1	.50
V FRP (ms)	246.2±32.1	247.7±24.9	.76
Induction of AVNRT
RAE	1600 (49.3%)	26 (40.0%)	.14
RAP	2332 (71.8%)	42 (64.6%)	.20
RVE	273 (8.4%)	8 (12.3%)	.26
RVP	517 (15.9%)	8 (12.3%)	.43
Isoproterenol	1337 (41.2%)	28 (43.1%)	.76
Atropine	104 (3.2%)	3 (4.6%)	.78
TCL (ms)	350.1±69.7	364.6±74.4	.13
Transient AV nodal block	61 (1.9%)	7 (10.8%)	<.001
Residual SP after ablation	588 (18.1%)	10 (15.4%)	.57
Single echo beat post ablation	649 (20.0%)	13 (20.0%)	.99
Fluoroscopy time (minutes)	15.0±13.0	14.3±12.6	.71

* Retrograde slow pathway function was not compared owing to limited cases. AVNRT: atrioventricular nodal reentry tachycardia; AVNF: atrioventricular nodal fast pathway; AVNS: atrioventricular nodal slow pathway; ERP: effective refractory period; FRP: functional refractory period; RAE: right atrial extrastimuli; RAP: right atrial pacing; RVE: right ventricular extrastimuli; RVP: right ventricular pacing; SP: slow pathway; TCL: tachycardia cycle length

TABLE 2 The comparisons of electrophysiological parameters between index and repeat procedures

Patients with recurrences <3 years (n=48)			Patients with recurrences >3 years (n=17)
Index procedure	Repeat procedure	P value	Index procedure	Repeat procedure	P value
AH interval(ms)	83.4±16.2	82.2±20.4	0.61	76.5±13.1	99.1±23.4	<.01
Antegrade conduction
AVNF 1:1 (ms)	405.5±112.9	398.6±83.5	0.70	359.4±43.9	395.4±115.9	.23
AVNF ERP (ms)	341.3±85.6	347.6±88.7	0.41	300.6±70.6	345.6±106.3	.11
AVNF FRP (ms)	429.6±82.5	427.5±81.7	0.80	382.2±65.5	410.8±84.0	.06
AVNS 1:1 (ms)	380.4±79.5	332.9±52.8	0.47	340.0±66.0	425.0±49.5	.21
AVNS ERP (ms)	302.4±78.6	310.8±64.1	0.06	276.4±39.5	285.5±34.1	.98
AVNS FRP (ms)	535.9±139.8	579.6±116.1	0.05	496.6±85.7	448.8±94.4	.25
AERP (ms)	225.1±31.2	237.0±52.0	0.20	225.8±23.9	226.2±16.8	.67
AFRP (ms)	258.1±42.5	268.8±53.8	0.18	240.2±21.7	262.9±27.3	.22
Retrograde conduction *
AVNF 1:1 (ms)	385.7±78.1	370.4±84.4	0.34	390.0±73.3	392.0±74.4	.83
AVNF ERP (ms)	322.9±77.1	293.7±92.8	0.99	252.9±28.7	303.5±80.7	.96
AVNF FRP (ms)	383.7±71.2	370.5±101.2	0.83	342.4±48.2	383.0±67.3	.16
V ERP (ms)	221.0±26.0	221.2±23.0	0.61	220.1±28.1	224.0±17.3	.05
V FRP (ms)	249.1±26.3	241.7±22.0	0.39	242.1±18.5	252.5±18.5	.16
Induction of AVNRT
RAE	18 (37.5%)	26 (54.2%)	0.15	8 (47.1%)	7 (41.2%)	.99
RAP	33 (68.8%)	39 (81.2%)	0.24	9 (52.9%)	12 (70.6%)	.48
RVE	5 (10.4%)	3 (6.2%)	0.71	3 (17.6%)	2 (11.8%)	.99
RVP	4 (8.3%)	1 (2.1%)	0.36	4 (23.5%)	6 (35.3%)	.71
Isoproterenol+/‐­Atropine	23 (47.9%)	30 (62.5%)	0.22	8 (47.1%)	15 (88.2%)	.03
TCL (ms)	368.8±73.9	348.0±102.1	0.53	351.5±77.8	365.3±54.7	.87

* Retrograde slow pathway function was not compared owing to limited cases. The abbreviation as Table 1 and Table 2.

AP19‐­00165

Short Koch triangle predict fast junctional rhythm during AVNRT ablation

Masanori Yamamoto, Motomi Tachibana, Kimikazu Banba, Kensuke Matsumoto, Shun Higashikawa

The Sakakibara Heart Institute of Okayama, Japan

Introduction:

Fast junctional rhythm (JR) during slow pathway modification for atrioventricular nodal reentrant tachycardia (AVNRT) is a predictor of serious atrioventricular block. This study investigated the shape of the heart who is likely appearing fast JR during ablation with 3D electroanatomical mapping in AVNRT patients.

Methods:

Participants were 129 consecutive patients with common AVNRT who received anatomical ablation to an antegrade slow pathway at our institution between August 2013 and March 2019. Successfully ablated sites with JR were evaluated in terms of distances and angles in the left and right anterior oblique views (LAO and RAO, respectively) to the proximal His bundle (His) site using 3D mapping. We divided JR by heart rate: JR1 ≥ 150 bpm and JR2 < 150 bpm.

Result:

Average age was 61 ± 16 years; 41.1% of patients were male. The distance from the most proximal His to the JR1 and JR2 site was not significantly different (11.9 ± 4.4 vs 10.7 ± 4.5 mm, P = .24). JR1 predominantly appeared in the patients with wider angle between most proximal His to CS ostium (JR1 131.6 ± 14.6° vs JR2 124.7 ± 11.2°, P < .01). No significant differences in baseline clinical characteristics were observed between JR1 and JR2 in other parameters.There were no acute complications of AV block. AH time before and after ablation did not differ (85.1 ± 17.5 vs 83.7 ± 16.4, P = .49).

Conclusion:

The wider angle from the proximal His to the CS os in LAO seemed to one of the predictors of the appearance of fast JR. These results could help operators determine appropriate ablation sites so as to avoid serious complications of AV conduction.

AP19‐­00175

A case of atrioventricular reentry tachycardia circuiting between left and right accessory pathway

Kazuaki Amami, Naoko Hijioka, Takashi Kaneshiro, Shinya Yamada, Masashi Kamioka, Takafumi Ishida, Yasuchika Takeishi

Fukushima Medical University, Japan

Introduction:

A 65 years old man was hospitalized with cerebral infarction. An implantable loop recorder was implanted to detect subclinical atrial fibrillation and it revealed short lasting both narrow and wide QRS tachycardia. The twelve leads electrocardiogram showed negative delta wave in inferior leads and positive delta wave in V1 lead. These suggested the existence of left posterior accessory pathway (LPAP).

Methods:

We performed an electrophysiological study (EPS) and catheter ablation for diagnosis and treatment of the atrioventricular reentry tachycardia.

Result:

EPS showed ventricular‐­atrial (VA) conduction via both LPAP and right lateral accessory pathway (RLAP) respectively during ventricular pacing, and VA conduction via RLAP showed alternating 2 to 1 conduction. Orthodromic atrioventricular reentrant tachycardia (AVRT) via LPAP was induced by ventricular programed stimulation, but orthodromic AVRT via RLAP could not be induced. During EPS, wide QRS tachycardia with right bundle brunch block was induced by atrial pacing. Intracardiac electrocardiogram during this tachycardia showed that atrial‐­ventricular (AV) conduction run through LPAP and VA conduction run through RLAP. The His wave did not precede the V wave at His region during tachycardia, that suggested this tachycardia as AVRT circuiting between LPAP and RLAP. This AVRT was not tolerant hemodynamically, and was terminated with rapid atrial pacing immediately. Firstly, we performed catheter ablation for LPAP and LPAP was eliminated. After eliminating LPAP, we performed catheter ablation for RLAP. During catheter mapping for RLAP, orthodromic AVRT via RLAP occurred and was terminated with VA block by catheter ablation. Interestingly, AV conduction via RLAP appeared transiently during catheter ablation for RLAP although it had never been observed clinically.

Conclusion:

AVRT circuiting between both sides of AP is rare and is intolerant hemodynamically.

AP19‐­00217

The feasibility of cryofreezing ablation for atrioventricular nodal reentrant tachycardia (single center experience)

Kei Yamamoto, Jun Hirokami, Junji Morita, Masato Fukunaga, Michio Nagashima, Kenichi Hiroshima, Kenji Ando

Kokura memorial hospital, Japan

Introduction:

The atrioventricular nodal slow pathway ablation has been already established as the treatment for atrioventricular nodal reentrant tachycardia (AVNRT). However the large volume data of efficacy of cryoablation for AVNRT has not been clear. Therefore, we reported single center experience of catheter ablation using cryoablation catheter (Freezer Extra, Medtronic®️, Minnesota, USA)for common AVNRT.

Methods:

A total of 74 patients with common AVNRT underwent catheter ablation using cryoablation catheter. The endpoint of procedure was defined as A‐­H jump without one echo beat and that was obtained in all 74 patients.

Result:

The rate of complete elimination of the slow pathway conduction was 64%, AH jump without an echo beat was 0%, and AH jump with a single echo beat was 36%. During a mean follow‐­up of 550 ± 307 days, freedom from recurrence was 2.7% (2 patients). No patients had any permanent atrioventricular block.

Conclusion:

The clinical result of catheter ablation for AVNRT using cryofreezing catheter was feasible.

AP19‐­00220

Usefulness of a variable circular decapolar catheter placed in the coronary sinus ostium in patients with atrioventricular reentrant tachycardia and persistent left superior vena cava

Hideomi Fujiwara, Nobuhiro Nishiyama, Masahiro Morise, Yuhei Isonaga, Takanobu Yamada, Chinatsu Komiyama, Mitsuhiko Ota, Yo Fujimoto, Takanobu Kodama

Cardiology, Japan

Introduction:

Persistent left superior vena cava (PLSVC) is the most common anomaly of the thoracic venous system. Some reports show that PLSVC is associated with the development of AV node reentrant tachycardia. There is some difficulty to decide the appropriate site for slow pathway ablation especially a patient with coronary sinus ostium enlargement.

Methods:

A 54‐­year‐­old women suffered from palpitations due to paroxysmal supraventricular tachycardia (PSVT) for twenty years. The preoperative echocardiogram and computed tomography revealed she had PLSVC. She underwent an electrophysiology study and ablation for PSVT using a variable circular decapolar catheter placed in the coronary sinus (CS) ostium under 3D mapping system guidance. And three catheters were positioned in the high right atrial (HRA), His bundle, right ventricular apex (RVA), and CS.

Result:

The patient was induced into an PSVT when a premature atrial beat at 440 milliseconds was delivered after eight consecutive paced beats at a drive cycle length of 600 milliseconds. Phenomenon “jump” in the AH interval was noted prior to initiation of tachycardia. The atrial activation pattern was concentric with earliest atrial activation seen on the His catheter. Successful atrial entrainment during RVA pacing produced a V‐­A‐­V response. Para‐­Hisian pacing indicated retrograde conduction over the fast atrioventricular (AV) nodal pathway. These findings provided a diagnosis of atrioventricular reentrant tachycardia (AVNRT). During electrophysiology study, a circular decapolar catheter (7‐­8) recorded the small potential that suggests slow pathway potential. Slow pathway ablation was performed under 3D mapping system with circular decapolar catheter, after the ablation the patient could no longer be induced into any tachycardia despite multiple attempts at reinduction with and without isoproterenol.

Conclusion:

A variable circular decapolar catheter placed in the CS ostium may be useful in a catheter ablation for AVNRT complicated by PLSVC

AP19‐­00221

Atrial tachycardia originated from posterior vein of left ventricle

Nanqing Xiong, Xinping Luo, Alexios Hadjis, Vasanth Vedantham

Huashan Hospital Fudan University, China

Introduction:

Although coronary sinus (CS) musculature is a common origin for focal atrial tachycardia (AT), ATs from ventricular branches of coronary sinus are rarely documented. Here we report an AT originating from the posterior vein of left ventricle(PVLV), which was successfully ablated where large V potential was present.

Methods:

A 49‐­year old transgender male presented with recurrent episodes of palpitation. EKG during symptom seemed to be supraventricular with a long R‐­P interval. Previous history included patent fossa ovalis. Electrophysiology study and ablation was performed.

Result:

Retrograde conduction demonstrated “nodal” pattern during para‐­Hisian pacing and retrograde right bundle branch block. Narrow complex tachycardia (cycle length approx. 320 milliseconds) could be readily induced by atrial pacing from CS ostium without A‐­H jump. Earliest atrial activation was at CS5‐­6. Ventricular overdrive pacing was associated with termination of tachycardia and failure to entrain. We paced atrium at tachycardia cycle length and measure A‐­H interval, which was found identical to that during tachycardia, thus making AVNRT unlikely. We went across the PFO and map the left atrium. During tachycardia the earliest activation site was at mitral annulus (the same activation time as CS5‐­6), where ablation failed to terminate the tachycardia. Then ablator was pulled out of LA and map the coronary sinus. Local activation time (LAT) was 11 milliseconds earlier than earliest CS bipole (CS catheter moved). Burning here was still unsuccessful. Then venogram was performed to look for potential local anatomical abnormalities inside CS. No aneurysm or diverticulum was discovered but PVLV was found near the earliest activation site. Ablator at the ostium of the vein recorded a larger V, suggesting the close relationship with ventricular epicardium. But local A was even earlier than in the main branch of CS (15 milliseconds earlier than CS). After the catheter position was confirmed not being adjacent to any coronary artery branch, RF was delivered and tachycardia was terminated within one second.

Conclusion:

AT originating from the musculature of ventricular branch of CS can be identified with small and early A with large V inside CS branch. Venogram can be helpful in clarifying the anatomy of coronary vein system in specific cases. Although the origin was at the “ventricle side”, it was considered to have no direct connection to the ventricles, but has electrical conduction to atria through CS instead.

AP19‐­00242

Dual accessory pathways identified in a single activation map with Rhythmia; a case report

Shu Yamashita, Akira Mizukami, Hirofumi Arai, Jiro Hiroki, Akihiko Matsumura, Tetsuro Sasano

Kameda medical center, Japan

Introduction:

Multiple accessory pathways (AP) are identified by the change of the earliest activation after ablation to the earliest activation site by the initial mapping. We describe a case of dual anterior APs that were identified in a first activation map with Rhythmia.

Methods:

N/A.

Result:

A 69‐­year‐­old male who suffered from recurrent palpitations was referred to our institution. 12‐­lead ECG showed no delta wave and no antegrade AP conduction was observed by the intracardiac electrical mapping. Right ventricular apex (RVa) pacing showed a retrograde left side AP and ventricular premature stimuli induced narrow QRS tachycardia. This arrhythmia demonstrated the reset phenomenon by RVa extra‐­stimuli, and we diagnosed it as orthodromic atrioventricular reciprocating tachycardia. Initial activation map with Rhythmia at the mitral annulus (MA) during RVa pacing revealed that the earliest atrial activation was at the anterior MA (AP1). In the same activation map, we could identify another AP (AP2), that conducting to left atrium at 18 mm lateral side of MA from the AP1 and 15 milliseconds later than the AP1. Ablation at the earliest atrial activation at the anterior MA (AP1) changed the earliest activation to the slightly lateral side of MA, and radiofrequency (RF) energy application at this site successfully eliminated the AP conduction.

Conclusion:

High spatial resolution mapping with Rhythmia visualized dual accessory pathways within 2 cm in a single mapping, that was able to lead effective and successful ablation.

AP19‐­00244

Thirty‐­year trend reversal of paroxysmal supraventricular tachycardia subtype in Korea: Role of female social status

Seung Jin Jun, Ki Hong Lee

Gunsan Medical Center, South Korea

Introduction:

Dominant subtype of paroxysmal supraventricular tachycardia (PSVT) has been known as atrioventricular reentrant tachycardia (AVRT) in South Korea with old reference, in contrary to atrioventricular nodal reentrant tachycardia (AVNRT) in Western countries. Recent trend of PSVT has not been evaluated despite of immerse increment of PSVT ablation. Therefore, we aimed to investigate serial trend of PSVT in Korea during 30‐­year, and aimed to evaluate determinant factors for the trend change.

Methods:

A total of 3377 patients underwent electrophysiologic study (EPS) due to PSVT in Chonnam National University Hospital from January 1988 to December 2017. PSVT were classified as AVNRT, AVRT with concealed bypass tract (CBT), AVRT with manifested bypass tract (MBT), and atrial tachycardia (AT). Temporal trends of PSVT subtype was analyzed by annual year and 5‐­year. Multivariate regression analysis was performed to identify independent factors for the change of temporal trends.

Result:

In the early period, from late 1980s to early 1990s, AVRT with MBT was the dominant form of PVST. Until 2006, AVRT with CBT showed most remarkable increasing trend, constituting AVRT (the sum of AVRT with CBT and AVRT with MBT) as the dominant form PSVT in Korea. However, dominant form of PSVT has been reversed to AVNRT since 2007. Because of remarkable increment of AVNRT during last the last decade, overall ratio of AVNRT during 30‐­year is higher than AVRT or AT (48.4% vs 43.2% vs 8.4%, P < .001). In the analysis of annual genderic incidence, gender ratio was reversed from 2:1 at the early 1980s to 1:1 at the late 2000s. During the latest decade, prevalence of female gender is even higher than male gender (52.1% vs 47.9%, P < .001). Multivariate regression analysis demonstrated that female gender was the independent factor (adjusted odds ratio 2.8, 95% confidence interval 1.63‐­3.54, P = .002) for the change of temporal trend.

Conclusion:

Contrary to earlier reports for the incidence of PSVT subtype in Korea, AVNRT is the most dominant form of PSVT. Also, PSVT constitution has been changed from AVRT to AVNRT since 2007. Female gender was the most important determinant factor the change of temporal trend, which might be associated with the improvement of social position of women in Korea, resulting in easy access to hospital.

AP19‐­00277

Preferential conduction through cavotricuspid isthmus revealed by ultra high resolution mapping in typical flutter

Gang Yang, Cheng Cai, Benqi Wang, Fengxiang Zhang, Weizhu Ju, Hongwu Chen, Mingfang Li, Kai Gu, Minglong Chen

Xxxx, China

Introduction:

Linear ablation of the cavotricuspid isthmus (CTI) has been recognized as a highly successful and safe technique in the treatment of typical atrial flutter. However, it could be extremely difficult in some patients. The possible explanation would be complex and individual anatomy of the CTI. And the anatomic property could be translated into different activation patterns through the CTI. The purpose of this study was to test the hypothesis that CTI conduction is not in step and preferential conduction could be revealed by ultra high‐­resolution mapping.

Methods:

A total of 28 patients with typical flutter were included between September 2016 to August 2018 (average age: 52 ± 16 years, right atrium: 39 ± 5 mm, left ventricular ejection fraction: 60 ± 9%). High‐­resolution 3D mapping (Rhythmia mapping system, Boston Scientific, Natick, Massachusetts) was performed. Maps were analyzed retrospectively to characterize wave front propagation patterns in CTI region. The length of CTI, the width of preferential conduction area and their ratio were measured. The relationships between the ratio and termination or cycle length prolongation were also evaluated.

Result:

16 (57%) patients underwent previous cardiac surgery. 1 (3%) patient has received previous ablation in CTI. There are five different activation patterns through CTI (Figure 1). Type I in 4 patients (14%) was homogenous conduction without preferential wave front though CTI. Type II in 15 patients (53%) was with preferential wave font close to tricuspid annulus. Type III in 1 patients (3%) was with preferential wave front in the middle of CTI. Type IV in 7 patients (25%) was with preferential wave front close to inferior vena cava (IVC). Type V in 1 patients (3%) was with double preferential wave fronts. We found that the termination sites were exactly located at preferential wavefront in 18 of 28 patients (64%). The width of preferential wave front in termination group was shorter than those in non‐­ termination group (16.6 ± 1.0 mm vs 23.3 ± 3.4 mm, P = .025). The cycle length (CL) prolongation (20 milliseconds longer than baseline) before termination was noted in 16 of 28 patients (57%). However the width of preferential wave front in CL prolongation group was similar with those in non‐­prolongation group (18.4 ± 1.5 mm vs 19.8 ± 3.0 mm, P = .655). the relationship between the ablation reaction and the ratio (the width of preferential wave front and CTI) were showed in table 1.

Conclusion:

Activation conduction through CTI is heterogeneous. The preferential conduction was common and the majority was close to tricuspid annulus. If the preferential conduction is more apparent, it is more likely to terminate atrial flutter during ablation exactly at the preferential wave front site.

KEYWORDS Ablation; Cavotricuspid isthmus; preferential conduction; Typical atrial flutter

FIGURE 1 Different patterns of preferential wavefront through CTI

TABLE 1 The relationship between ablation reaction at preferential wave front and the ratio of width of preferential wave front to CTI. (PW: preferential wave front)

AP19‐­00288

Physician feedback on the use of activation mapping with integration of vector and velocity information

Yenn‐Jiang Lin, Livio Bertagnolli, Christian Meyer, Nicolas Derval, Malte Kuniss, Lars Karlsson, Jean Paul Albenque, Jérôme Lacotte, Mattias Duytschaever

Taipei Veterans General Hospital, Taiwan

Introduction:

Activation maps of atypical atrial tachycardias (AT) are often difficult to interpret because of a variety of factors (e.g. inaccurate/inconsistent annotations, multiple activation patterns etc.). An activation mapping algorithm (Coherence Map, CM) integrating vectors was developed to help determine the arrhythmia mechanism, identify its critical components and simplify the activation representation of complex scar‐­related arrhythmias. The objective of this evaluation was to gather clinical feedback from operators and evaluate the general acceptance of the concepts behind activation mapping integrating vectors, its visualization elements and performance, and its ability to serve as an efficient tool for mapping complex, scar related arrhythmias such as atypical atrial flutters.

Methods:

The evaluation was performed through prospective, multi‐­center systematic physician surveys of performance evaluation across 10 sites in EMEA and 1 site in Taiwan, with feedback from a total of 184 cases. Majority of the mapping was performed with either Pentaray catheter (159) or Lasso catheter (20).

Result:

Majority (120/184) of the arrhythmias was identified as macro‐­reentrant AT. Overall satisfaction of CM features was high (5.79/7.00 Likert scale). Physicians’ feedback revealed that in 93% of the cases, CM represented activation maps the same or better than regular Local activation time (LAT) maps; in 72% of the cases, CM was rated better than LAT (Figure). Final ablation strategy was based, all or in part, on CM in 154 of the 184 cases recorded. In 78 cases, only CM was used. Lastly, in 41% (76 /184) of the cases, CM provided additional information to the physicians leading to changes in ablation treatment strategy.

Conclusion:

The novel CM represented atypical AT better than regular LAT maps in the majority of cases and had a significant impact in the final ablation strategy.

AP19‐­00350

Administration of adenosine triphosphate provides additional value over programmed electrophysiologic study in confirmation of successful accessory pathway ablation

Wei Wei, Pengda He, Wenxiang Huang, Yumei Xue, Xianzhang Zhan, Hongtao Liao, Xianhong Fang, Yuanhong Liang, Shulin Wu, Haiyan Liu

Guangdong Provincial People's Hospital, China

Introduction:

Both programmed electrophysiological study (PES) and medication including injection of adenosine or adenosine triphosphate (ATP) can confirm the absence of accessory pathways (APs). Many electrophysiologists prefer PES alone to test the endpoint. We wondered if the administration of ATP in combination with PES could be superior to PES alone in the outcome of AP ablation.

Methods:

We reviewed consecutive patients with supraventricular tachycardias due to APs demonstrated by intracardiac PES that underwent radiofrequency catheter ablation from January 2016 to September 2018 in our center. The patients were divided into two groups, the ATP group (who had passed both the ATP test and PES after ablation as the endpoint) and the non‐­ATP group (who had passed PES only after ablation as the endpoint). We reviewed patients’ intra‐­cardiac electrograms and analysed the long term outcomes of the two groups.

Result:

In total 1343 patients with APs underwent successful radiofrequency ablation during this period. There were 215 patients in the ATP group with one patient lost to follow‐­up. There were 1128 patients in the non‐­ATP group with 39 lost to follow‐­up. Twenty‐­three patients in the ATP group demonstrated additional electrophysiological entities due to ATP administration, including reappearance of the ablated APs in 16 patients, discovery of PES‐­undetected APs in five patients, induction of paroxysmal atrial fibrillation in five patients, induction of premature atrial contractions in one patient and induction of premature ventricular contractions in one patient. During 7‐­39 months (average 24.4 ± 9.5 months) follow‐­up, the recurrence rate was 8.41% (18/214) in the ATP group, and 6.80% (74/1084) in the non‐­ATP group. In subjects with a recurrence, fourteen patients (14/18 = 77.8%) in the ATP group and 50 patients (50/74 = 67.6%) in the non‐­ATP group accepted redo ablations. Among the ATP‐­group, all the redo‐­APs were the same ones as previously. Among the non‐­ATP‐­group, redo ablations confirmed that 39 APs were the same ones as previously, while 20 APs were newly detected which had been missed by previous procedures. Differences in recurrent AP locations between the two groups was significant (P = .008). All the patients in the ATP group experienced transient drug related symptoms and demonstrated short lived A‐­V conduction block managed with temporary ventricular pacing.

Conclusion:

The inherent existence of multiple APs was an important cause for recurrence when ATP administration is not used to confirm ablation endpoints and the use of ATP adds additional value over PES alone in confirmation of ablation endpoint of APs by detecting latent APs. ATP is also helpful in induction of some arrhythmias due to triggered activity. With the use of ventricular pacing, the ATP test is safe in patients without contraindications to this agent.

AP19‐­00366

Termination of incisional atrial tachycardia without global capture by single atrial pacing in the patient with open‐­cardiac surgery; a case report

Daisuke Yakabe, Masahiro Araki, Akemi Aso, Toshihiro Nakamura

National Hospital Organization Kyushu Medical Center, Japan

Introduction:

Termination without global capture was reported as the finding to identify critical part of the re‐­entrant circuit for scar‐­related ventricular tachycardia. However, there were few reports about this phenomenon in atrial tachyarrhythmia.

Methods:

N/A.

Result:

The present case was a 46‐­year‐­old woman with past history of open‐­cardiac surgery using superior trans‐­septal approach for mitral valve prolapse. Atrial tachycardia (AT) occurred after the surgery and it was refractory to anti‐­arrhythmic drugs, and then she was admitted to our hospital for catheter ablation. Electroanatomical mapping with CARTO3 system revealed that AT was macro‐­ reentrant AT involving incision line at right atrium (RA). Fragmented continuous potentials were identified at lower lateral RA adjacent to incision line. Single atrial pacing at this site was performed to avoid phrenic nerve injury, and it could terminate AT without global capture. AT could not be inducible due to bump of ablation catheter, then radiofrequency applications were performed at this site under sinus rhythm. The conduction block was confirmed in the RA by differential pacing. There was no recurrence of AT for 2 years after catheter ablation.

Conclusion:

We reported the rare case of termination without global capture in the patient with incisional AT. This phenomenon is an important finding showing a critical slow conduction zone in atrial tachycardia as well as ventricular tachycardia.

AP19‐­00373

Two cases of epicardial endocardial breakthrough during macroreentrant atrial tachycardia revealed by the RHYTHMIA mapping system

Masayuki Ohta, Kentaro Hayashi, Hiroyuki Sato, Mitsugu Hirokami, Satoshi Yuda

Teine Keijinkai Hospital, Japan

Introduction:

The RHYTHMIA Mapping System (Boston Scientific) reveals epicardial endocardial breakthrough (EEB) in some cases of macroreentrant atrial tachycardia (MRAT), and EEB suggests an epicardial circuit of MRAT. However, there are no established treatment strategies for MRAT with EEB. We present two cases of successfully ablated MRAT with EEB.

Methods:

N/A.

Result:

Case 1 is a 76‐­year‐­old man who presented with atrial tachycardia (AT) 6 months after tricuspid valve replacement and the right‐­sided Maze procedure. Although the RHYTHMIA Mapping System revealed the scar area along the cavo‐­tricuspid isthmus (CTI) ablation line by the previous right‐­ sided Maze procedure, the activation map indicated CTI‐­dependent clockwise flutter, and EEB was detected at the lateral side of the CTI ablation line (Figure A). The differences between the post pacing interval (PPI) and the tachycardia cycle length (TCL) at the lateral tricuspid annulus and coronary sinus ostium were 18 and 16 milliseconds, respectively. However, the PPI at just the lateral side of the CTI ablation line was 84 milliseconds longer than the TCL. Although radio frequency ablation to the EEB site was not effective, the tachycardia was terminated by mechanical bump just on the CTI ablation line. After several radio frequency applications to that area, the tachycardia was no longer induced, and bidirectional block of CTI ablation line was confirmed. Case 2 is a 70‐­year‐­old man who presented with AT after pulmonary vein isolation and roof line linear ablation using a cryoballoon system. The RHYTHMIA Mapping System revealed the scar area along the roof line. However, activation map suggested roof‐­dependent AT, and EEB was confirmed at the anterior side of the roof line (Figure B). The differences between the PPI and the TCL at the left atrial anterior wall and the left atrial posterior wall were 4 and 2 milliseconds, respectively. Although pacing from just the anterior side of the roof line was not captured, the AT terminated in 2.4 seconds with TCL prolongation by radio frequency application to that point, and bidirectional block of the roof line was confirmed.

Conclusion:

In MRAT with EEB, an epicardial critical isthmus estimated by the RHYTHMIA mapping system could be an ablation target, even if a pacing was not captured or the PPI was long.

AP19‐­00388

Sustained double firing of atrioventricular non‐­reentrant tachycardia mis‐­interpreted as ventricular arrhythmia

Isaiah Lugtu, Yenn‐Jiang Lin

Taipei Veterans General Hospital, Taiwan

Introduction:

The differential diagnosis of wide QRS tachycardia is challenging.

Methods:

N/A.

Result:

A 52‐­year‐­old male presented with palpitations for 10 years. Right parahisian ventricular tachycardia (VT) was diagnosed and ablated previously. Recurrence of symptom prompted consult. During electrophysiologic study, frequent non‐­sustained wide QRS tachycardia with right bundle branch block (BBB) morphology and a wobbling tachycardia cycle length was noted. Right paraseptal recording showed 1 atrial (A) followed by 2 ventricular (V) signals preceded by intermittent right bundle potential. Advancing the ablation catheter to left ventricular septum demonstrated left bundle branch (LBB) potential preceding each QRS. One A signal followed by 4 V signals was also observed implying the possibility multiple AVN non‐­reentrant phenomenon. Atrial pacing reproducibly induced sustained “1P 2Q” with fixed coupling interval of slow pathway, reflecting “double fire” of dual atrioventricular nodal non‐­reentrant tachycardia (DAVNNT). Different LBB‐­V interval was observed during the fast and slow pathway conduction, emphasizing the involvement of LBB responsible for this phenomenon. Tachycardia was terminated after elimination of the slow pathway.

Conclusion:

DAVNNT can be mis‐­interpreted as VT, especially when there is BBB pattern. Involvement of slow pathway could extend to LBB as shown in our case. Detailed recording of both RBB and LBB potentials can provide clues for diagnosis.

AP19‐­00398

Complete bidirectional conduction block of the Marshall bundle‐­left atrium connection utilizing high‐­resolution 3D mapping system

Kazumasa Suga, Yasuya Inden, Toshifumi Nakagomi, Koichi Furui, Shuro Riku, Keita Mamiya, Hiroya Okamoto, Toshiro Tomomatsu, Aya Fujii, Satoshi Yanagisawa, Toyoaki Murohara

Department of Cardiology, Nagoya University Graduate School of Medicine, Japan

Introduction:

Atrial tachycardia (AT) involving an epicardial connection of the Marshall bundle (MB) has been recently reported. We present a case in which the MB‐­left atrium (LA) connection was observed using a high‐­resolution 3D mapping system.

Methods:

A 69‐­year‐­old man with AT was admitted for catheter ablation. He had a history of multiple catheter ablation procedures of bilateral extensive pulmonary vein isolation, complex fractionated atrial electrogram, roof and bottom lines, mitral isthmus block line, cavotricuspid isthmus line, and superior vena cava isolation. During the AT (cycle length 308 ms), an endocardial activation map in the LA was attempted with the Rhythmia mapping system using Orion mapping catheter (Boston Scientific, Marlborough, MA).

Result:

The activation map revealed a macro‐­reentrant AT including the left atrial appendage (LAA), mitral annulus, and the scar tissue at the mitral isthmus in a counterclockwise direction. However, the local activation time did not fulfill the cycle length of the AT. Suspecting an involvement of epicardial connection of the vein of Marshall (VOM), a 2‐­Fr octapolar electrode catheter was inserted into the VOM through a coronary sinus, and electrograms on the VOM were recorded. The activation map involving the MB potentials completely fulfilled the entire reentrant circuit. The post‐­pacing interval at the VOM was equal to the tachycardia cycle length. Radiofrequency ablation was subsequently applied at the left atrial ridge targeting the VOM close to the potentials recorded in the 2Fr catheter, and the AT successfully terminated. Thereafter, both MB and local LA potentials were identified on the electrograms of the VOM during the LAA pacing. The activation sequence on the electrogram of the MB was distal to proximal, which indicated the residual connection of a distal MB‐­LA site. The high‐­resolution mapping during LAA pacing demonstrated an accurate site of the distal MB‐­LA connection. Immediately after ablation of the site, the first potentials (MB potentials) were markedly delayed and were not distinguishable from the second potentials (local LA potentials). It was assumed that only one connection (MB‐­CS) had been left conducting in this case. The differential pacing site method showed that the conduction time from the distal portion of the VOM to LAA (181 ms) was longer than that from the proximal portion of the VOM to LAA (155 ms), which confirmed complete bidirectional block of the MB‐­LA connections. No further ATs were induced after the procedure.

Conclusion:

We illustrated the case in which a high‐­resolution mapping could identify the precise breakthrough site from epicardium to endocardium via the MB, facilitating spot ablation to terminate AT and to achieve bidirectional conduction block of the MB‐­LA.

AP19‐­00404

Trans‐­thoracic echocardiography guided ablation of left lateral accessory pathway

Vikas Kataria, Gautam Singal, Mohan Nair

Holy Family Hospital, India

Introduction:

Radiofrequency catheter ablation (RFA) of majority of the arrhythmias is currently done under fluoroscopy guidance. In recent years, Electroanatomic Mapping and Intra‐­Cardiac Echocardiography have been used to facilitate precise definition of anatomy and reduce fluoroscopy time. Echocardiography guided transseptal puncture and placement of diagnostic catheters has been reported previously.^1,2 To the best of our knowledge, use of trans‐­thoracic echocardiography (TTE) for mapping and ablation of arrhythmia has never been reported. We present a case of left lateral accessory pathway ablation done predominantly under trans‐­thoracic echocardiography (TTE) guidance with minimal use of radiation.

Methods:

A thirty year old lady with symptoms of recurrent palpitation and documented supraventricular tachycardia was taken‐­up for electrophysiological study (EPS) and RFA.

Result:

EPS was done after fluoroscopy guided placement of diagnostic catheters. Tachycardia induced with atrial pacing revealed orthodromic tachycardia using a left lateral accessory pathway. Subsequent procedure, RFA, was done without the use of radiation. Trans‐­septal puncture and manipulation of mapping catheter around mitral annulus were done solely under TTE guidance (Figure 1 and 2). Successful RFA of accessory pathway was done with single RF energy application (400c, 60W) at the site of A‐­V fusion.

Conclusion:

TTE guided catheter ablation of left‐­sided accessory pathways is simple, feasible and merits further attention. This technique may be especially helpful in preventing x‐­ray exposure in particularly in children and pregnant women.

AP19‐­00406

Adenosine sensitive focal atrial tachycardia from the mitral annulus in rheumatic valve disease

Vikas Kataria, Vipul Malpani, Mohan Nair

Holy Family Hospital, India

Introduction:

Focal Atrial tachycardia (AT) that is responsive to intravenous Adenosine, although infrequent, has been described; but only one report has described such an AT arising from the Mitral Annulus. Adenosine responsive AT arising from a diseased Mitral Valve has not been previously described.

Methods:

A 56 years old female, who was a known case of Rheumatic Mitral Valve Disease (RMVD) of more than 19 years, presented with history of frequent episodes of palpitations since 1 month. The electrogram during episodes showed a long RP narrow QRS tachycardia at a rate of 188 bpm (Figure 1A). Each episode of tachycardia was terminated by intravenous administration of 12 mg Adenosine Tri Phosphate. Echocardiography evaluation showed moderate Mitral Stenosis (MVA = 1.3 cm²) with moderate mitral valve regurgitation. The left ventricular size and function was normal. The left atrial diameter was 3.3 cm.

Result:

After informed consent, electrophysiology study was done in the post‐­absorptive state, under local anesthesia. Quadripolar catheter was positioned in the right atrium (RA) and a decapolar catheter was positioned in the Coronary Sinus (CS). The Tachycardia was reproducibly induced by rapid atrial pacing; it was not induced on isoprenaline Infusion and did not show a warm‐­up or cool down phenomenon. Intracardiac signals showed earliest atrial activation in the mid‐­ CS and late activation in the RA (Figure 1B). A 4 mm Irrigated Tip Ablation Catheter (FLEXABILITY™ irrigated ablation catheter, Abbot Vascular, Salt Lake, Santa Clara, CA, USA) was positioned at the mitral annulus via trans‐­septal puncture. Pacing maneuvers done at the mitral annulus around the earliest atrial activation site, did not show entrainment with concealed fusion and the post pacing cycle length was 50 milliseconds longer than the tachycardia cycle length. Ventricular Extra Stimulus during tachycardia elicited a VA‐­AV response. Mapping along the annulus showed a site with atrial electrogram 10 milliseconds earlier than the earliest atrial electrogram in the CS catheter; with an electrogram duration of 30 milliseconds (Figure 2). The above features were consistent with a focal AT. A single Radio‐­Frequency energy (60W, 60o, 17 mL/second) terminated the tachycardia within ten seconds of energy application (Figure 3). The tachycardia remained non‐­inducible at 15 minutes post ablation.

Conclusion:

(a) Focal atrial arrhythmia arising along a diseased mitral annulus may appear late in the history of rheumatic heart disease. (b) This is the first report where such an AT from an area of significantly diseased mitral valve has been shown to be sensitive to Adenosine. This could indicate a paradigm shift, as generally in patients with structural heart disease and AT, Adenosine has not been a preferred drug for cardioversion. (c) Radiofrequency catheter Ablation should be the treatment of choice for such arrhythmia.

FIGURE 1 12 Lead electrocardiogram at the time of presentation shows a long RP, narrow QRS tachycardia at the rate of 188 bpm.

FIGURE 2 A, RF ablation at the mitral annular site with earliest activation resulted in tachycardia termination within 10 s. B, Fluoroscopic image from the successful RF ablation site. The image shows quadripolar catheter in HRA, decapolar catheter in CS and the ablation catheter at the mitral annulus

AP19‐­00512

Safety and efficacy using high‐­power and short‐­duration ablation for cavotricuspid isthmus ablation

Hee‐Jin Kwon, Young Keun On, Seong Soo Lee, Young Jun Park, Seung‐Jung Park, Kyoung‐Min Park, June Soo Kim

Samsung Medical Center, South Korea

Introduction:

There have been many studies on high‐­power and short‐­duration ablation in atrial fibrillation (AF) patients. However, limited data exists on cavotricuspid isthmus (CTI) ablation for atrial flutter (AFL). We evaluated the efficacy and safety of high‐­power and short‐­duration ablation for CTI ablation.

Methods:

Eighty‐­four patients who underwent CTI ablation between January 2018 and February 2019 were randomly assigned 1:1 to a high‐­power group (50W for 15 seconds) and low‐­power group (30W for 60 seconds). CTI ablation was performed in patients with documented AFL or AFL induced during ablation for AF. We analyzed procedural characteristics, periprocedural complications and recurrence of any type of atrial tachyarrhythmia (ATa).

Result:

Total 84 patients (mean 57.8 ± 10.3 years old, and 86% were male) were randomly assigned high‐­power group (n = 42) and low power group (n = 42). Bidirectional CTI block was achieved in all patients and 95% of them achieved bidirectional block after the first line ablation in both groups. Although there was no difference in the total ablation number between the two groups (1.17 ± 0.7 vs 1.39 ± 0.8, P = .159), high power group showed shorter total ablation time (235.9 ± 85.6 seconds vs 550.4 ± 233.8 seconds, P < .001). One pericardial tamponade and one atrioventricular block were reported in high power group and one pulmonary vein stenosis was reported in low power group (P = .314). During the mean follow‐­up of 214.5 ± 126.8 days, CTI‐­dependent AFL recurrence was occurred in one patient in high power group. Recurrence of ATa exclude blanking period were developed in nine patients in high power group and five patients in low power group, respectively (21% vs 12%, P = .242).

Conclusion:

Our study demonstrated that high‐­power, short‐­duration CTI ablation was safe and could shorten the procedure time.

AP19‐­00524

Atrial arrhythmias in patients with adult congenital heart disease

Sein Khine, Jemelee Hernandez, Tan Nee Hooi, Tan Boon Yew, Ho Kah Leng, Chong Thuan Tee Daniel, Teo Wee Siong, Lim Tien Siang Eric, Lim Chun Yih Paul, Chua Chi Ming Kelvin, Ching Chi Keong

National Heart Centre Singapore, Singapore

Introduction:

Catheter ablation is performed to treat atrial tachyarrhythmias in adult congenital heart disease (ACHD). However, the rate of recurrence is reported to be up to 50%. We aim to describe the electrophysiological findings, procedure details, and recurrence at 6 months after catheter ablation in patients with ACHD.

Methods:

Patients with ACHD who underwent catheter ablation for atrial arrhythmias at the National Heart Centre Singapore between January 2017 and December 2018 were studied. Pre‐­specified clinical and procedural data of interest and time from ablation to recurrence were obtained by chart and procedure report review. Patients with atrial arrhythmias after Maze procedures were excluded.

Result:

16 patients with ACHD and atrial arrhythmias underwent catheter ablation; their ACHD diagnoses were atrial septal defect (ASD) (37.5%, n = 6), atrioventricular septal defect (18.8%, n = 3), ventricular septal defect (12.5%, n = 2), tetralogy of Fallot (12.5%, n = 2), pulmonary stenosis (12.5%, n = 2) and complex congenital heart disease with transposition of great vessels, ventricular septal defect and pulmonary stenosis (6.25%, n = 1) were studied. Female was 81%. Mean age was 59 ± 13 years. All patients had previous surgical correction of defects except one patient with ASD. Mean left ventricular ejection fraction was 54 ± 9%. A total of 24 arrhythmias were inducible. The EP diagnoses were cavotricuspid isthmus (CTI) dependent flutter (42%), intra‐­atrial reentry flutter around atriotomy scar (38%), RA free wall flutter (8%), atrial tachycardia (8%) and peri mitral flutter (4%). 50% of patients had two arrhythmias mechanisms. Mean procedure time was 176 ± 79 minutes. Mean radiofrequency ablation time was 1185 ± 761 seconds. Mean Fluoroscopy time was 19 ± 16 minutes. No sustained atrial tachyarrhythmias were induced after ablation. Acute procedural success rate was 87.5% without any complication. Patients were followed over a median of 368 days (Interquartile range‐­ 127‐­438 days). At 6 months follow‐­up, recurrence occurred in five patients (31%) with two arrhythmia mechanisms. Of these five patients with recurrence, three patients underwent a repeat ablation with 100% success.

Conclusion:

Catheter ablation of atrial arrhythmias in patients with ACHD is effective and safe. More than one arrhythmia mechanism has a higher risk of recurrence.

AP19‐­00525

A‐­38 years old multiparous women with supraventricular tachycardia, cardiomyopathy and recurrent pregnancy loss: Is it tachycardia‐­induced cardiomyopathy?

Iman Setiadi, Anggi Larasati, Mahek Munawar, Reyhan Muhammad F, Rossalia Visser, Agung Fabian Chandranegara

Pasar Rebo General Hospital, Indonesia

Introduction:

SVT is the most common arrhythmia during pregnancy with a prevalence of 24 per 100 000 admissions. Patients with pre‐­existing SVT may experience exacerbations during pregnancy.

Methods:

Case Illustration: A 38‐­yrs old G5P1A3 woman presented to emergency at 37w of gestation with complaint of palpitation and dyspnoea. There was no history of cardiovascular disease. She lost her first baby at 24w gestation, and her second pregnancy at 28w gestation. In her 3rd gestation, she had her first baby. In her 12 w gestation of fourth pregnancy, she had another pregnancy loss. On her exam revealed BP of 130/70, HR 220 bpm and respiratory rate of 36x/m, and the rest of the clinical examination was unremarkable. An ECG showed SVT, Long RP interval suspected AVRT (AV re‐­ entrant tachycardia). Echo evaluation showed dilatation of LV and LA, global hypokinetic of left ventricle with reduced EF of 26%, 3rd Grade diastolic dysfunction LV, moderate mitral regurgitation, and mild tricuspid regurgitation. All of the lab values were within normal limits, and chest X‐­ray showed no acute intrathoracic process. Then we administered 15 mg iv diltiazem but there was no response and the second dose of 20 mg of diltiazem was given after 15 minutes but SVT still persisted. Because the haemodynamic was then unstable we decided to perform cardioversion. Biphasic cardioversion was performed immediately in a stepwise fashion (100 J, 150 J, 200 J), but it didn't convert to sinus rhythm. Not long after, she had regular uterine contractions and vaginal examination revealed full cervical dilatation. The baby was born spontaneously with cyanosis and Apgar score of 3. Neonatal resuscitation started immediately, but the death was pronounced minutes later. Then Patient being moved to ICCU. Patient treated with 150 mg Amiodarone given iv bolus, then she was maintained on amiodarone 360 mg/6 hours and 540 mg for further 18 hours iv. Her condition was getting stable then she was discharged with a ventricular rate of 130 bpm with medication furosemide, spironolactone and bisoprolol.

Result:

We presented a case, a gravid patient with recurrent pregnancy loss with SVT and severely reduced LV systolic function. There was no history of cardiovascular disease, so the tachycardia in this patient is a known cause of cardiomyopathy, called as tachycardia‐­induced cardiomyopathy (TIC). High ventricular rates initially result in cardiac dilatation and mitral regurgitation. However, in patients with TIC, the LVEF and symptoms improve or normalize when the tachycardia is controlled. Coronary angiography is necessary if doubt remains regarding potential ischaemic aetiology of left ventricular dysfunction.

Conclusion:

Tachycardia‐­induced cardiomyopathy should be considered in all patient whose systolic dysfunction diagnosed subsequent to or concomitant with tachyarrhythmia.

FIGURE 1 12‐lead ECG

FIGURE 2 Echocardiogram

AP19‐­00548

Left olique accessory pathway ablation in a patient with congenital heart disease—Case report

Ngoc Phan

Tam Duc Hospital, Ho Chi Minh City, Vietnam

Introduction:

Only child, full‐­term birth, cesarean delivery, birth weight: 3.4 kg Since 2012, she discovered congenital heart disease at 5 months old with diagnosis of Double AV discordance—ASD, VSD—Pulmonary atresia—Abnormal position of great arteries She had operation at Tam Duc Hospital in 2012 (BT shunt) and 2015 (Glenn shunt and PA enlargement) Since 2016, she's had several episodes of tachycardia, each lasts #15‐­30 minutes, terminate spontaneously. Few months later, the tachycardia became persist. During tachycardia (HR 210‐­220 bpm), she had dyspnea, sweating, increased cyanosis and occasionally vomited · admitted to Khanh Hoa Hospital with hypotension · terminate SVT with Cordarone IV. Treatment with Amiodarone 100 mg + Bisoprolol 2.5 mg qd. During medication, the patient still suffered from many episodes of symptomatic tachycardia required termination with cordarone IV. In 2018, the episodes of symptomatic SVT become more often (1‐­2 episodes/month) even with high dose of AAD (Bisoprolol 5 mg + Cordarone 100 mg) · admitted to TD Hospital for SVT ablation During SVT, her blood pressure dropped significantly and she was near‐­syncopy.

Methods:

AP Ablation with 3D mapping.

Result:

Successfully ablation left oblique AP.

Conclusion:

Paediatric patients with congenital heart disease represent unique challenges to the interventional electrophysiologist. The advent of both mapping and ablative technologies and understanding of arrhythmia mechanism, has helped us to ablate successfully this case.

AP19‐­00551

Multiple approaches for the ablation of atrial tachycardia originating from right upper pulmonary veins

Nanqing Xiong, Henry Hsia, Jian Li, Wentao Gu, Xinping Luo

Huashan Hospital Fudan University, China

Introduction:

Pulmonary veins are common sources of focal atrial tachycardia (AT). AT originating from right upper pulmonary veins (RSPV) are frequently encountered and can mimic AT from posterior right atrium (PRA) due to their close anatomical relationship. Double potentials (DPs) recorded from PRA or RSPV are helpful in distinguishing the true foci of the arrhythmia.

Methods:

5 patients with RSPV‐­AT underwent electrophysiology study (EPS) and radiofrequency catheter ablation (RFCA). Surface ECG were carefully analyzed before procedure. During mapping, the morphology of DPs (far‐­field vs. near‐­field) could be utilized to differentiate RSPV origins from PRA origins (Figure 1). RSPV‐­AT was confirmed by the earliest near‐­field atrial activation in RSPV. If early far‐­field potential is recorded at PRA, RSPV‐­AT was also highly suspected. Para‐­venous pacing maneuver was used for identification of electrical connection between RSPV and PRA. Ablation strategies included (A) Direct RF delivery at PRA where DPs were present; (B) Focal ablation at the earliest activation site if it was at the ostium of RSPV; (C) Circumferential isolation of RSPV or right pulmonary veins (Figure 2).

Result:

All 5 patients had monophasic positive P wave in V1 and inferior leads during tachycardia. P wave in lead I were positive in 3 patients and flat in 2 patients. Mean cycle length was 274.8 ± 103.9 msec. DPs could be recorded in 3/5(60%) patients from either PRA or RSPV, with a mean time interval between both potentials of 39.7 ± 4.0 msec. All 5 ATs were successfully ablated. The earliest activation time was 89.4 ± 7.8 msec prior to coronary sinus. Direct ablation at PRA where DPs were recorded was performed in three patients but was associated with tachycardia elimination in only one patient. In the other four patients, either focal ablation or pulmonary vein isolation was done. Para‐­venous pacing was performed in 3 of them and electrical connection between RSPV and PRA was identified in one patient. Considering the safety and effect, pulmonary vein isolation was performed if the target was deep inside the pulmonary vein and no connection between PRA and RPV, otherwise focal ablation was carried out. Long‐­term freedom of tachycardia was achieved in all of them and no pulmonary vein stenosis or phrenic nerve injury was observed.

Conclusion:

A typical “posterior‐­superior and septal” origin on surface ECG and local DPs during mapping at PRA/RSPV were helpful in the diagnosis of RSPV‐­AT. Ablation can be performed via multiple approaches, among which direct RF at PRA seems less effective. Decision between pulmonary vein isolation and focal ablation can be made based on the proximity of the target to RSPV ostium, and whether there's electrical connection between RSPV and PRA.

TABLE 1 Baseline data, EP/ECG characteristics and ablation results

Patient 1	Patient 2	Patient 3	Patient 4	Patient 5
Age (years)	64	33	36	69	55
Gender	Female	Female	Male	Female	Male
Cycle Length (ms)	416	220	175	353	210
V1	+	+	+	+	+
I	+	0	+	0	+
Double Potentials	+(PRA)	+(PRA)	+(RSPV)	‐­	‐­
Time Interval between DPs (ms)	44	39	36	‐­	‐­
Earliest LAT prior to CS (ms)	88	99	95	86	79
RSPV‐­PRA Connection	Not performed	Not performed	‐­	+	‐­
Target at RSPV ostium	‐­	+	‐­	+	‐­
Ablation Strategy	Abl. at PRA	Focal Abl. in RSPV	RSPV Isolation	Focal Abl. in RSPV	RSPV Isolation
Success	+	+	+	+	+
Complications	‐­	‐­	‐­	‐­	‐­

PRA, posterior right atrium; RSPV, right superior pulmonary vein; DPs, double potentials; LAT, local activation time; CS, coronary sinus; Abl., ablation.

FIGURE 1 Double potentials during mapping

FIGURE 2 Different approaches for RSPV‐­AT: A, RF delivery at PRA; B, Circumferential PV isolation; C, Focal ablation

AP19‐­00557

Acute occlusion of a branch of left circumflex artery after radiofrequency catheter ablation for atrial tachycardia

Akihiro Komasa, Satoshi Shizuta, Munekazu Tanaka, Shintaro Yamagami, Takashi Yoshizawa, Takeshi Kimura

Department of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University, Japan

Introduction:

There are a few reports on acute occlusion of coronary arteries after radiofrequency catheter ablation. But their mechanism and incidence are not still well known.

Methods:

We performed the catheter ablation for mitral atrial tachycardia occurred after the ablation for paroxysmal atrial fibrillation. In the session, we performed radiofrequency ablation on mitral isthmus line and in coronary sinus.

Result:

After the last ablation session, we found that a branch of left circumflex artery was occluded. In this case, creatine kinase was slightly elevated, but the patient had no chest complaints, and no ECG changes were observed.

Conclusion:

We experienced acute occlusion of a branch of left circumflex artery after catheter ablation in coronary sinus. In this case report, we discuss the mechanism and incidence of this complication after catheter ablation, and how to avoid and manage it.

AP19‐­00612

Two different type of atrial tachycardias originating from left and right atrium in lung transplantation patient

Khac Le Son Nguyen, Hui Nam Pak

Cho Ray Hospital, Ho Chi Minh City, Viet Nam, Vietnam

Introduction:

Atrial arrhythmias commonly occur following lung transplantation. When medical treatment fails to control the arrhythmia, catheter ablation should be considered.

Methods:

We present an unusual case of two different type of atrial tachycardias arising from left and right atriums, respectively.

Result:

A 61‐­year‐­old male underwent bilateral lung transplantation for pulmonary fibrosis. He had no prior history of arrhythmias or any other structural heart disease. Immediate postoperative period was complicated by atrial fibrillation that proved responsive to antiarrhythmic agents. After 2 months, the patient presented with shortness of breath and palpitation. He was found to be in narrow‐­complex tachycardia. He failed management with rate‐­controlling agents and antiarrhythmic drugs. Therefore, the patient was referred for electrophysiological study and ablation. Activation map showed that earliest activation was in the anastomosis around left superior pulmonic vein (LSPV). We successfully ablated this tachycardia at the site of earliest activation. However, another atrial tachycardia was induced. Entrainment maneuvers performed at near the coronary sinus ostium showed post pacing interval equal to tachycardia cycle lengths it was correspond with cavotricuspid isthmus (CTI) dependent atrial flutter. Radiofrequency ablation was performed at the CTI site, which terminated the AFL to sinus rhythm and no longer inducible atrial tachycardia even after administration of isoproterenol. No procedural complications occurred. The patient was free of symptoms and arrhythmia episodes without any antiarrhythmic medication during the 3‐­month follow‐­up period.

Conclusion:

This case is a rare presentation of two different type of atrial tachycardias originating from anastomosis line of LSPV and CTI dependent reentrant circuit, respectively. Increased risk of AF beyond being inactive.

AP19‐­00620

Not all need 3D

Ahmad Faiz Bin Mohd Ezanee, Mohd Firdaus Mohd Ali, Ru Hoi Tan, Chew Wei Leong, Yi Zhi Cheng, Ahmad Shukri Saad, Sathvinder Singh Gian Singh, Saravanan Krishinan

Hospital Sultanah Bahiyah, Malaysia

Introduction:

Three‐­dimensional mapping (3‐­D) systems are frequently used for ablation of supra‐­ ventricular tachycardia (SVT). Studies have demonstrated radiation dosage reduction with 3‐­D, helps to protect patient and the health provider from radiation. However, not all cases that are done under 3‐­D guidance are successful. This is our first experience in our centre whereby 3‐­D guidance cardiac ablation not able to terminate the SVT, but with conventional radio‐­frequency ablation (RFA) therapy do terminate the SVT in a symptomatic 7 years‐­old girl with Wolf‐­ Parkinson White (WPW) Syndrome with history of SVT. She was admitted in January 2019 for persistent tachycardia with heart rate 200 beats per minute and tachycardia terminated with Adenosine. ECG post Adenosine showed short PR interval with present of delta wave.

Methods:

ECHO: Good Ejection Fraction, normal finding with no pericardial effusion nor clot/thrombus Baseline in WPW ‐­AP 1:1 340 (mild‐­to moderate Antegrade risk) ‐­AP ERP 600/360 (mild to moderate Antegrade risk) ‐­VAB non‐­ demonstrable, concentric ‐­SVT CV 360 ‐­Mapping earliest V Anteroseptal just above His ‐­RF ablation eliminate antegrade AP ‐­V pacing mapped earliest A in the same vicinity ‐­RF ablation here terminate retrograde AP conduction

Result:

Post RF: No AH jump with atrial extra‐­stimulus testing (AEST). ‐­Parahisian pacing nodal response seen ‐­Adenosine 12 mg given and atrioventricular block (AVB) & ventriculoatrial block (VAB) seen Impression: Right Anteroseptal accessory pathway (AP) causing orthodromic reciprocating tachycardia (ORT).

Conclusion:

In conclusion, even though 3‐­D cardiac ablation is equally effective and safe with conventional RFA, not all cases are successful under 3‐­D guidance. Careful ECG & EGM interpretation is mandatory to determine successful procedure outcome.

AP19‐­00623

Successful radiofrequency ablation of multiple accessory pathways: The first in North Sulawesi

Ira Posangi, Evan Gunawan, Benny Setiadi, Janry Pangemanan, Lucia Panda, Muhammad Munawar

Cardiology and Vascular Medicine, Sam Ratulangi University, Manado, Indonesia

Introduction:

Multiple atrioventricular accessory pathways (MAPs) were accounted for 3%‐­20% patients undergoing electrophysiology study (EPS) for pre‐­excitation syndrome. It was also associated with a higher risk for ventricular fibrillation. A thorough EPS is required to determine the presence MAPs after which catheter ablation is performed. MAPs demonstrated a satisfying long‐­term success rate of single session radiofrequency ablation.

Methods:

A woman, 52 years old, was admitted due to recurrent palpitation that had led her to emergency department at least forty‐­two times before. No history of syncope, chest pain nor dyspnea ever occurred. The EPS exhibited an AVRT after RV pacing with earliest VA on CS3‐­4, followed by a trans‐­septal puncture, and an ablation on CS3‐­4. However, a later atrial pacing still resulted on an AVRT, thus another accessory pathway was suspected. Subsequently, VA fusion was found on anteroseptal LV (1 o'clock direction) where another ablation was performed. Eventually, further RV pacing conducted no more AVRT. This case was part of the first EPS series ever performed in North Sulawesi and was the first successful RF ablation of MAP in North Sulawesi history.

Result:

The existence of MAPs could either be assessed by the findings of ≥2 pathways during a single EPS; or ≥2 new pathways on a subsequent EPS ‐­ located differently from the one where ablation was completed previously. A meticulous mapping of the atrium and ventricle activation pattern is needed to identify the accessory pathway on which radiofrequency ablation is going to be delivered. A search for a second or more accessory pathway is performed if the first one is successful, followed by another ablation procedure.

Conclusion:

The incidence of MAPs varied widely on patients with pre‐­excitation syndrome, while its existence had been correlated to a higher rate of certain malignant arrythmia. Through a comprehensive EPS and delivery of RF ablation, patients with MAPs had been able to be treated with a favorable long‐­ term outcome.

AP19‐­00628

Usefulness of high‐­resolution mapping in detecting localized reentry circuits of atrial tachycardia

Masatsugu Nozoe

Saiseikai Fukuoka General Hospital, Japan

Introduction:

A case was 82 years‐­old female. We decided to perform catheter ablation for atrial tachycardia (AT).

Methods:

AT was easily induced by atrial burst pacing (AT1). We got activation mapping of AT1 using the Advisor HD Grid Mapping Catheter with Ensite system.

Result:

The activation mapping detecting centrifugal activation pattern with the earliest activation point at anterior left atrium (LA), however, sparkle mapping revealed localized reentry circuit at anterior LA. Energy application targeting fragmented potential could terminate AT1. Because she had history of paroxysmal atrial fibrillation (AF), we performed pulmonary vein (PV) isolation. After PV isolation, AT2 was induced by atrial burst pacing. AT2 could not influenced by a liner ablation of LA roof and a liner ablation between right superior PV and mitral valve. Re‐­mapping of AT2 revealed localized reentry circuit at infero‐­lateral LA. Energy application targeting fragmented potential could terminate AT2. Neither AT nor AF could be induced after catheter ablation.

Conclusion:

We reported a rare case of the patient with two different localized reentry circuits. High‐­ resolution mapping was useful for detecting localized reentry circuits.

AP19‐­00676

Radiofrequency catheter ablation of para‐­hisian accessory pathways in children: Strategy for mapping and ablation

Lin Liu, Shaoying Zeng, Zhenheng Ou, Cong Liu, Zhilin Li, Boning Li, Shushui Wang, Zhiwei Zhang

Shenzhen Children's Hospital, Shenzhen, China

Introduction:

Radiofrequency catheter ablation (RFCA) of parahisian accessory pathways (APs)in children can be challenging due to their anatomic proximity to the normal conduction tissue. Recent studies have suggested that parahisian APs can be successfully ablated by different approaches, including the right anterior septum (RAS), the noncoronary cusp(NCC),and the left anterior septum (LAS). The study aims to evaluate the efficacy and safety of parahisian APs in children.

Methods:

A retrospective review was performed with 34 pediatric patients[18 males and 16 females; mean age 7.8 ± 3.5 years and average body weight 27.8 kg) with parahisian APs in two centers from 2015 to 2017.18 patients had manifest APs. All the children underwent RFCA for the treatment of PSVT except one for treatment of non‐­arrhythmic pre‐­excitation‐­induced cardiomyopathy. During mapping at the para‐­hisian region in RAS. We used a pacing technique to differentiate the near‐­field from far‐­field His activation. On the basis of response to parahisian pacing, we performed different ablation approaches which targeted at either the RAS or the NCC or LAS.

Result:

Acute ablation success was achieved in 29 cases (85%, 29/34). Ablation was abandoned for the suspicion of atrioventricular conduction in three patients because of near‐­field response during parahisian pacing. Para‐­hisian APs were successfully ablated in the RAS in 22 cases (76%), in the LAS in one cases (3%), in the NCC in six cases (20%).No atrioventricular block occurred during the procedures except one with RBBB. After a mean follow‐­up of 21.5 ± 5.5 months, SVT recurrence was observed in 5 of 22 patients (23%) ablated in the RAS group, 0 of the 6 patients in NCC group (P < .05). Three patients underwent two procedures, and two patients underwent three procedures, and the total successful rate was 91% (31/34).

Conclusion:

Most para‐­Hisian APs in children can be safely and effectively ablated in RAS. If mapping in RAS shows characters of near‐­field during parahisian pacing, Ablation in the NCC is preferred because it has a lower complication rate, and good long‐­term outcome.

Keywords: Accessory pathway; Catheter ablation; Para‐hisian; pediatric; supraventricular tachycardia

AP19‐­00701

A multicenter prospective controlled study of catheter ablation for patient with paroxysmal super ventricular tachycardia with domestic radio frequency current ablation device

Pengkang He

Peking University First Hospital, China

Introduction:

To verify the efficacy and safety of domestic radio frequency device for catheter ablation of paroxysmal super ventricular tachycardia (PSVT).

Methods:

From June 2016 to September 2017, 140 patients from 3 hospitals were enrolled into this multicenter prospective controlled study. The patients were allocated into experiment group (domestic device) and control group(foreign device) in equal number(70 vs 70). The experiment group ablated with OptimAblate^®TM radio frequency current ablation device (MicroPort Shang Hai), while the control group used EP SHUTTLE device (Johnson & Johnson). The immediate ablation success rate and the incidence of adverse events were observed.

Result:

Of the 70 patients in experiment group, 68 received ablation therapy and 67 in control group. Both groups achieved a 100% immediate success rate. The incidence of adverse events in experiment group were 20% (14/70) with 31.88% in control group (22/69). The difference between two groups didn't meet statistical significant. No severe adverse events had been reported and 1 adverse event was defined as “probably related” with the experiment device.

Conclusion:

The domestic ablation device was as effective and safe as foreign device for PSVT treatment.

AP19‐­00730

Transmural activation dynamics of the sinus node in structural heart disease: Mechanistic insights for arrhythmogenesis

Ramanathan Parameswaran, Christophe Teuwen, Troy Watts, Chrishan Nalliah, Geoffrey Wong, Hariharan Sugumar, Robert Anderson, Ahmed Al‐Kaisey, David Chieng, Alistair Royse, John Goldblatt, Marco Larobina, Peter Kistler, Geoffrey Lee, Jonathan Kalman

Royal Melbourne Hospital, Australia

Introduction:

Sinoatrial dysfunction and atrial arrhythmias frequently coexist in presence of structural heart disease (SHD). While atrial remodelling is frequently implicated, there is paucity of data on electrical activation from an endocardial‐­epicardial perspective. We tested the hypotheses that electrical dissociation and signal fractionation will be present in the sinus node region with overdrive suppression with SHD. We also assessed activation and conduction dynamics of the sinus node region from an endocardial‐­epicardial perspective.

Methods:

Simultaneous intra‐­operative mapping of the endo‐­ and epicardial aspects of sinus node region was performed during sinus rhythm at baseline (SRb) and after overdrive pacing (SRd) using two Advisor· HD Grid catheters (Abbott, 16 electrodes, 3 mm inter‐­electrode spacing). Unipolar EGM's and 3‐­D electrode locations were exported into custom‐­made software for phase mapping, activation times and for assessing signal complexities and conduction velocities (CV). Difference ≥20 milliseconds between paired endo‐­ and epicardial electrodes defined dyssynchrony. Unipolar electrograms with ≥5 deflections occupying were classified as fractionated.

Result:

Sixteen patients (mean age: 60.5 ± 4.1 years, 18.7% history of AF) with SHD (43% ischemia, 57% valvular disease) were included. 4862 EGM's analysed. With SRb, 90%±0.2% of activations were synchronous, but this significantly reduced to 85.1%±0.2% (P < .0001) with SRd with a tendency towards epicardial exits (46.3% vs 40.3%). Overall, 44.4% of the unipolar EGM's in the sinus region showed fractionation. Although the proportion of complex signals were similar on epicardial and endocardial surfaces (49.5% vs 50%), fractionated signals were more frequent during sinus rhythm post over drive pacing than at baseline (48% vs 39.5%, P < .0001). Mean CV's did not differ between endo‐­ and epicardial surfaces during SRd (53.9 vs 51.7 cm/s, P = .545)

Conclusion:

Significant endocardial‐­epicardial electrical dissociation and electrogram fractionation is evident in the sinus node region post overdrive suppression in patients with SHD with a tendency towards epicardial exit. Such complex 3D interaction in electrical activation provides further mechanistic insights for arrhythmogenesis in the presence of SHD.

AP19‐­00732

Experience of atrial tachycardia ablation using 3D mapping system

Nwe Nwe, Thet Lel Swe Aye

Yangon General Hospital, Myanmar, Burma

Introduction:

Atrial tachycardia is not a common cause of supraventricular tachyarrhythmias. The overall success rate and complications of atrial tachycardia ablation by using 3D mapping system were studied.

Methods:

Patients with atrial tachycardia who underwent radiofrequency ablation using 3D mapping system from June 2015 to June 2019 were retrospectively studied through the case records.

Result:

A total of 28 patients (male 4, female 24) with atrial tachycardia underwent electrophysiological study with 3 D mapping system. Majority of patients (42%) were in the 41‐­60 years age group. Most patients (No = 23, 82%) had atrial tachycardia from RA focus and 5 patients (18%) had focus in left atrium. Among the patients with right sided atrial tachycardia, most patients (No = 9, 39%) had Crista origin. Ablation was successful in 20 patients including 1 patient with para‐­hisian focus. Among the patients with left sided atrial tachycardia, successful ablations were done for the focus at the roof of left atrium near right superior pulmonary vein, anterior part of left inferior pulmonary vein, left perinodal and anterior mitral annulus. Ablation was successful in 24 patients (85%), including 20 patients with atrial tachycardia from RA focus and four patients with LA focus.

Conclusion:

Although the centre had low volume of cases in 4 years, high success rate (85%) was achieved with negligible complications.

AP19‐­00766

Multifocal atrial tachycardia in young adult with Marfan syndrome

Intan Toekan

Binawaluya Cardiac Center, Indonesia

Introduction:

Marfan syndrome is a systemic disorder of connective tissue resulting from a mutation in the fibrillin‐­1 gene. It is affected myocardial conductivity and predisposes for atrial and ventricular arrhythmias

Methods:

A 27 year old male patient came with chief complaint of frequent palpitations during the last 1‐­year. He had a history of PVC RVOT ablation in 2010 and 2011. His ECG showed sinus rhythm with incomplete RBBB and no arrhythmia. Echocardiography revealed normal cardiac function with no structural or valvular abnormality. He had above average height, pectus excavatum, scoliosis, long limbs, stretch mark, and hind foot deformity. A systemic score for Marfan syndrome showed a value of 7. Patient underwent an electrophysiology study and showed AV node dysfunction. Programmed electrical stimulation and administration of isoproterenol intravenous evoked multifocal atrial tachycardia from right lower right atrial and left sided. The patient is planned for further evaluation of Marfan syndrome with multidisciplinary team and 3D radiofrequency catheter ablation.

Result:

Atrial arrhythmias were rare in Marfan syndrome. It does'nt carry the same risk of sudden death as ventricular arrhythmias but are still clinically significant

Conclusion:

Atrial arrhythmias were rare in Marfan syndrome. It does'nt carry the same risk of sudden death as ventricular arrhythmias but are still clinically significant

Keywords: multifocal atrial tachycardia, young adult, Marfan syndrome

AP19‐­00801

Relationship of atrial tachycardia and dilated cardiomyopathy

Ken‐Pen Weng

Kaohsiung Veterans General Hospital, Taiwan

Introduction:

Frequent supraventricular tachycardia more than 120 bpm may cause cardiomyopathy. Arrhythmia with atrial fibrillation or flutter in the old population is most frequent associated with this form of tachyocardiomyopathy. We report a rare pediatric patient with atrial tachycardia and dilated cardiomyopathy and review the previous literature.

Methods:

A 15‐­year‐­old male patient with a diagnosis of severe dilated cardiomyopathy and atrial tachycardia was recruited. We examined the laboratory data, response to medical therapy, and follow‐­up of this patient.

Result:

This pediatric patient was referred from local hospital for cardiac transplantation. Initially, Echo showed severe dilation cardiomyopathy with LVEF about 15%‐­20%. EKG revealed atrial tachycardia with ventricular rate 130‐­140 bpm. Cardiac CT showed dilated cardiomyopathy with severe impaired contraction, but no scar. EF and wall motion examination showed LV 13.3%, RV 20.8%, and marked dilation of LV with severe general hypokinesia. Perfusion scan: persistent defect of LV in apex, anterior wall (20%‐­30% decrease), inferior wall (30%‐­40% decrease). Exercise test revealed maximal aerobic ability about 30.16% predicted. Major catheterization findings included dilated LV with moderate MR, PA pressure 54/39/45 mm Hg, RV pressure 57/8/17 mm Hg, RA pressure 22/23/16 mm Hg, LT PCWP 37/42/36 mm Hg, and CO 2.01 L/min. RV biopsy: hypertrophic myocytes and mild interstitial fibrosis without evidence of amyloidosis or myocarditis. Listing for cardiac transplantation was prepared. He was managed with digoxin, carvediol, propranolol, and diuretics. Transient sinus rhythm with ventricular rate 64 bpm occurred to him, and atrial tachycardia (120‐­130 bpm) persisted almost all day long. Amiodarone was prescribed and resulted in persistent sinus rhythm (60‐­80 bpm). Follow‐­up echo showed mild improvement of LVEF (20%‐­25%). He was relatively asymptomatic under CHF control and amiodarone treatment.

Conclusion:

Persistent atrial tachycardia may cause severe cardiomyopathy with requirement of cardiac transplantation, even in a pediatric patient. Optimal management of arrhythmia, using medical or ablation therapy, is a potential way to improve cardiac function.

AP19‐­00804

AVNRT with bizarre conduction

Monik Mehta, Yash Lokhandwala

Columbia Asia Hospital, India

Introduction:

A 42‐­year‐­old man patient presented with paroxysmal palpitations; the ECG revealed narrow QRS regular tachycardia, which terminated after adenosine. Clinical examination, 12 lead ECG and echocardiography were normal. At electrophysiology (EP) study, the baseline intervals were normal. The VA conduction was concentric and decremental and could not induce tachycardia. During atrial stimulation only narrow QRS complexes were seen. Atrial extrastimuli induced narrow QRS tachycardia with the intracardiac electrograms (EGMs) showing an ‘A on V’ sequence. The tachycardia then showed 2:1 AV conduction with intermittent wide QRS complexes (Figure 1A). There was no effect of ventricular extrastimuli on the tachycardia. What is the differential diagnosis?

Methods:

The differential diagnosis for A on V tachycardia with 2:1 AV conduction includes typical atrioventricular nodal reentrant tachycardia (AVNRT) and atrial tachycardia (AT). The intermittent wide QRS complexes (120 milliseconds, RBBB with superior axis morphology) appeared early, followed by a longer RR interval. Intracardiac EGMs (Figure 1B) at that time showed a premature ventricular signal with a shorter HV interval. The tachycardia cycle length (A‐­A interval) remained constant. Hence the wide QRS was a either a left posterior fascicular PVC or a preexcited complex.

Result:

The slow pathway was ablated with accelerated junctional ectopy during energy delivery. No tachycardia or wide QRS complexes could be induced thereafter, supporting the presence of a bystander nodofascicular (NF) pathway that manifested only during the 2:1 AV conduction. Since the atrial insertion of NF pathways is usually in close proximity to the slow pathway, this was simultaneously eliminated during slow pathway ablation. The VA conduction was unchanged after ablation.

Conclusion:

This case report highlights the extremely rare occurrence of a left NF bystander pathway in association with typical AVNRT.

AP19‐­00818

Dual tachycardia—An EP challenge

K. Kotti, V. Jaya Pradhap, S. Aishwarya, B. Radhika, S. Sabari, Mahima P. Manoj, G. Nithin, G. Sailendri, S. Benjamin, Ravi Kumar, S. Nirmala, Dasari Himaja, S. Sandini, K. Swathi, Ulhas M. Pandurangi

The Madras Medical Mission, India

Introduction:

Atrioventricular nodal reentrant tachycardia (AVNRT) is the most common regular supraventricular tachycardia (SVT) in clinical practice. Coexistence of more than one SVT in an individual patient is a well‐­known but infrequent phenomenon. The most frequently observed dual tachycardia is the combination of AVNRT with atrial fibrillation followed by atrial tachycardia (AT) and atrio‐­ventricular reciprocating tachycardia. We report an uncommon case of dual tachycardia‐­ AVNRT with focal AT and the challenges faced during successful ablation of the tachycardia.

Methods:

A 63‐­year‐­old female with no comorbidities and a structurally normal heart presented with recurrent palpitations. The baseline 12‐­lead ECG was normal and during palpitation it was short RP tachycardia. Patient was taken up for radio frequency (RF) ablation. Clinical tachycardia was induced with critical AH prolongation on atrial extra stimulus. While doing pacing maneuvers to establish the mechanism of tachycardia, it was converted to another narrow QRS tachycardia with long RP with P wave morphology similar to sinus rhythm. Transitions between 1st and 2nd tachycardia posed difficulties while assessing the arrhythmia mechanism as well as while testing for inducibility post ablation. First tachycardia was induced with critical AH prolongation and there were echo beats suggestive of AVNRT. Post ventricular overdrive pacing response for 2nd tachycardia was VAAV with earliest A at high crista region and was defined to be focal AT

Result:

While performing slow pathway modification, 2nd tachycardia was induced and so ablation was interrupted. After terminating the tachycardia few more RF energy delivered and successful modification of slow pathway was demonstrated. Activation mapping during atrial tachycardia showed earliest activation in the high crista region. Phrenic nerve capture was tested, RF energy delivered at the earliest site. Initial acceleration followed by termination of tachycardia occurred. Tachycardia could not be induced even with isoprenaline facilitation.

Figure A Clinical tachycardia‐­ AVNRT; Figure B: Induction of AVNRT by programmed atrial stimulation; Figure C: Conversion of AVNRT to AT during ventricular overdrive pacing; Figure D: shows atrial tachycardia cools down and spontaneous termination; Figure E: RV entrainment shows VAAV response for the 2nd tachycardia(AT); Figure F & G: Signals in the ablation catheter during tachycardia and sinus rhythm; Figure H & I: 3‐­D electro anatomical mapping showing ablation at earliest activation site with termination upon RF energy

Conclusion:

It has to be carefully determined whether concomitant atrial tachyarrhythmias are of clinical significance for further patient management or a nonspecific finding related to pacing maneuvers or pharmacological provocation. Some coexisting arrhythmias may no longer be inducible after successful slow‐­pathway ablation. Transition between the tachycardias poses challenges while establishing mechanism of tachycardia with pacing maneuvers as well as while ablating.

AP19‐­00820

Lesion maturation in AVRT ablation by RFA—How long do we wait?

Sanjeev S. Mukherjee

Medica Superspeciality Hospital Kolkata, India

Introduction:

Radiofrequency (RF) catheter ablation is an established modality of therapy in symptomatic AVRT (Atrioventricular re‐­entrant tachycardia). The accessory pathways are unevenly located in both tricuspid and mitral annuli. Among the existing locations left –sided fibres are most common .These can be accessed by antegrade transeptal, retrograde trans‐­aortic or very rarely via coronary sinus. All of these approaches have specific risks. We are discussing a case where after detailed consideration we avoided repeat transeptal puncture and also noticed RF lesion maturation after 12 hours. This emphasises need of proper post‐­ablation protocols to achieve good result.

Methods:

27 year old, male, patient suffered an episode of syncope with palpitation while working in office. He demonstrated WPW‐­syndrome with left sided pathway by baseline ECG(Electrocardiogram).The patient gave consent for RF ablation. He was taken for electrophysiologic study after stopping antiarrythmic drugs for 5 half lives under conscious sedation. Ketamin, Midazolam and propofol were used under anaesthetist supervision as needed. A 6‐­F decapolar catheter was positioned inside the coronary sinus. Other diagnostic catheters (6‐­F quadripolar) were placed in the right ventricular apex and bundle of His region and 5‐­F small sheath in right femoral artery. The baseline measurements of conduction and refractoriness were performed in sinus rhythm. The PR, QRS, QT, AH, and HV intervals, basal cycle length, and atrioventricular and ventriculoatrial Wenckebach cycle lengths were measured. Tachycardia got initiated while manipulating catheters. It was a narrow QRS tachycardia (NQRST) suggestive of orthodromic tachycardia. It started without jump and terminated with “a”. The pathway was mapped in sinus rhythm looking for early “v”.

Result:

The pathway disappeared within 3 beats of energy (60˚ C,40Watts). The lesion was further consolidated. We waited for 30 minutes and then performed “v” pacing and induction protocols post isoprenaline. While trying to get the catheter in left ventricle we lost access. When we tried to reassess with adenosine the antegrade pathway activity reappeared. We were not able to induce any tachycardia even after aggressive attempts. At this stage we were confident that this patient will not have tachycardia and repeat transeptal puncture had additive risk. We terminated the procedure and accepted reduced antegrade pathway conduction. The next morning ECG revealed total nodal conduction and 2 months phone follow‐­up reveals asymptomatic status.

Conclusion:

The above case stresses role of post ablation aggressive induction protocols to rule out future recurrences. This is our first case where we noted lesion maturation after 12 hours of index procedure reconfirming the practice of extensive mapping and meticulous first energy delivery.

AP19‐­00885

Incidence, clinical characteristics, electrophysiological characteristics and outcomes of patients with baseline PR prolongation undergoing radio frequency ablation for atrioventricular nodal reentrant tachycardia

Sameer Rane, Shomu Bohora

U.N.Mehta Institute of Cardiology, India

Introduction:

Atrio ventricular nodal reentrant tachycardia (AVNRT) is most common supraventricular tachycardia (SVT). PR prolongation on baseline electrocardiogram (ECG) is uncommon. Slow pathway ablation/modification is the recommended therapy for AVNRT. Slow pathway ablation/modification in patients having prolonged PR at baseline sinus rhythm is safe and effective and has been described in various studies.^11‐13 Incidence of AV block post procedure has been shown to be around 0%‐­9.3% in a various studies as compared to overall incidence of 0%‐­5% in unselect population. Those patients with higher PR interval (>300 milliseconds) have higher probability to develop AV block after slow pathway modification. Reithmann et al demonstrated that retrograde fast pathway ablation for patients with a first‐­degree AV block was associated with a higher intra procedural risk of complete AV block but did not result in the development of higher‐­degree AV block during the long‐­ term follow‐­up of up to 9 years. In this study we evaluate the safety and efficacy of slow pathway modification in patients with a baseline prolonged PR interval.

Methods:

Over 10 years, out of 1435 consecutive patients having AVNRT, 16 patients having PR prolongation at baseline were included in the study. Retrospective analysis of clinical, electrophysiological characteristics and outcomes was done.

Result:

Out of 1435 patients with AVNRT, 16 (0.9%) patients had baseline PR prolongation on ECG. Average age was 69 + 13.1 years. 10 (62.5%) were males. The average PR interval was 264 + 28.5 milliseconds. Slow fast AVNRT was seen in all. Anatomical site of success was lower part of Koch's triangle in all patients. Junctional rhythm was noted in all during ablation. No patient had AV block or significant increase in PR interval peri‐­procedure. PR interval decreased by more than 20 milliseconds in 10 (62.5%) patients post ablation. AH Wenckebach increased on an average of 58 milliseconds post ablation. Only one patient developed AV block on follow up.

Conclusion:

In patients having AVNRT, PR prolongation on baseline ECG is uncommon. Ablation at slow pathway can be done safely and effectively. AH Wenckebach point increases immediately post ablation. Risk of AV block persists on follow up.

TABLE 1 Table showing the basal characteristics of patients enrolled in this study

Baseline characteristics
Total number of patients of AVNRT	1435
Patients with PR prolongation at baseline	16 (0.9%)
Male	10
Female	6
Age	69 ±13.1 years
Presentation paroxysmal	15
Presentation incessant	1
PR interval at baseline	264 ± 28.5 ms
AH Wenckebach at baseline	355 ± 52.8 ms
Type of AVNRT slow‐­fast	16
Site of ablation below superior lip of CS os	15
Site of ablation above superior lip of CS os	1
Junctional rhythm during ablation	16
AV block during ablation	0
PR interval post ablation	229 ± 33.5 ms
AH Wenckebach post ablation	413 ± 75.3 ms
Dual AV nodal physiology post ablation/Echo beat	0
Number of patients in whom PR interval shortened (>20 ms) post ablation	12
Average change in PR interval	36 ± 35 ms (−74 to 6 ms)
Average AH Wenckebach increase post ablation	58 ms (20‐­180 ms)
Recurrence of tachycardia	0
AV block on follow up	1

TABLE 2 Tables showing changes in PR interval and AH Wenckebach pre and post ablation. Post ablation there was an average decrease in PR interval of 36 ms. Post ablation AH Wenckebach point showed an average increase by 58 ms

Patient	Pre ablation PR interval in msec	Post ablation PR interval in msec	Difference	Pre ablation AH Wenckebach point in msec	Post ablation AH Wenckebach point in msec	Difference
1	272	268	−4	380	450	70
2	270	210	−60	280	300	20
3	264	270	6	350	400	50
4	278	204	−74	380	420	40
5	269	212	−57	360	410	50
6	262	200	−62	320	500	180
7	271	250	−19	350	450	100
8	228	230	2	400	450	50
9	260	198	−62	500	600	100
10	240	220	−20	280	300	20
11	330	290	−40	300	320	20
12	240	210	−30	320	380	60
13	240	216	−24	360	400	40
14	280	201	−79	380	450	70
15	216	192	−24	360	380	20
16	308	289	20	350	400	50

FIGURE 1 Changes in PR interval and 2. AH Wenckebach, pre and post ablation

AP19‐­00901

Orthodromic reentrant tachycardia with electrical disconnection between coronary sinus and left atrium

Myo Han

North Okkalapa General and Teaching Hospital Yangon Myanmar, Myanmar

Introduction:

Electrophysiology (EP) study and radiofrequency (RF) ablation of supraventricuar tachycardia (SVT) is simple and successful in most of the time. Here we share our case with unusual coronary sinus activation during SVT.

Methods:

We did EP study on 26 years old female with documented supraventricular tachycardia (SVT) who had no procedure before. Retrograde study was eccentric with earliest atrial signal (A) at distal coronary sinus (CS) position. Tachycardia was induced with one extra right ventricle (RV) pacing and same CS activation as RV pacing (Figure 1). Pacing maneuvers were all consistent with Orthodromic Reentrant Tachycardia (ORT). Mapping was tried through retrograde aortic approach and mapped in tachycardia for earliest A signal and tried ablations for five times each lasted for about 15 seconds. During ablation we noticed CS electrical activation gradually changed from distal CS to proximal CS position though tachycardia cycle length remained not changed. Since CS activation changed, first thought as another tachycardia substrate and repeated diagnostic maneuvers again. His refractory premature ventricular complex (PVC) from both RV and left ventricle advanced next A consistent with atrioventricular reentrant tachycardia (AVRT). Since activation was earliest at proximal CS position, mapped around septal side of mitral valve ring and also on tricuspid valve ring for earliest A. During this we also noticed intermittent changing of CS activation back to distal CS position. Also on RV pacing, CS activation was eccentric.

Result:

Combined with this features, we mapped around initial ablation site again in tachycardia and found very closed VA around initial ablation site with discordant CS electrical activation which was delayed at that position and successfully ablated around that site (Figure 2).

Conclusion:

Although we can rely on CS activation sequence in SVT with eccentric VA conduction most of the time, it could sometime lead us in wrong way even.

AP19‐­00921

Successful ablation of atrioventricular nodal re‐­entry tachycardia at the apex triangle of Koch

Ahmad Suhaimi Mustafa, Sunu Budhi Raharjo, Dony Yugo Hermanto, Muqsith Muhammad, Dicky Armein Hanafy, Yoga Yuniadi

National Cardiovascular Centre Harapan Kita, Indonesia

Introduction:

Atrioventricular nodal re‐­entry tachycardia (AVNRT) is a common tachycardia. Radiofrequency ablation in AVNRT is safe and effective, whilst giving a very high successful rate up to 99%. In small percentage of patient however developed atrioventricular (AV) block as it may injure the AV node. We describe a case of successful AVNRT ablation near the apex of triangle of Koch.

Methods:

A case of 60 years old lady who referred for documented supraventricular tachycardia (SVT) ablation. No prior echocardiography done pre procedure. Three femoral vein punctures were done and inserted 7F and two 6F sheaths. Two quadripolar catheters 6F and 5F were placed at right ventricular (RV) apex and His bundle respectively. Non irrigated ablation catheter 4 mm tip 7F was placed at high right atrium (RA). Tachycardia with cycle length of 300 milliseconds was easily induced by atrial pacing. Right ventricular overdrive pacing (RVOP) manoeuvre at 280 milliseconds required more than 1 beat to follow which showed VAV pattern, with post pacing interval minus tachycardia cycle length more than 115 milliseconds (PPI‐­ TCL > 115 milliseconds) and VA interval 30 milliseconds. His‐­refractory ventricular premature beat (HRVPB) showed no reset. These findings consistent with typical slow‐­fast AVNRT. Slow pathway potential was mapped using ablation catheter (Figure 1).

Result:

Multiple radiofrequency ablation (RFA) was delivered at 30‐­40W, 60°C for 30s. Decent accelerated junctional rhythm was seen during ablation. Post ablation, the tachycardia was still inducible. Slow pathway potential was then mapped at different site such as roof of CS ostium. We finally mapped just below the His catheter which suggest apex of triangle of Koch (Figure 2). Despite catheter position very close to His, no His signal in ablation catheter (Figure 3). Successful ablation delivered at 40W, 45°C for 30 seconds gave decent accelerated junctional rhythm. Temperature and power were achieved, there was a dropped in impedance the first moment of ablation. Tachycardia was not inducible after 30 minutes ablation. Post ablation ECG showed sinus rhythm with no evidence of heart block. Total duration of procedure was 4 hours

FIGURE 1 Initial ablation at slow pathway potential in LAO 30, 0 view

FIGURE 2 Successful ablation at slow pathway. Note the location of His Catheter (above) and ablation catheter (below) which were very close

FIGURE 3 EGM of slow pathway potential at the site of ablation, in comparison with good His signal. Arrow at ablation catheter showed slow pathway potential, while arrow at His distal showed His signal

Conclusion:

Ablation of typical AVNRT sometimes can be challenging. Finding a good slow pathway potential will lead to successful ablation. In this case, although the position of ablation catheter very close to His catheter, the EGM did not show His potential. Ablation did not cause AV block as shown in this case.

AP19‐­00925

Left ventricle slow pathway successful ablation for atrioventricular nodal re‐­entry tachycardia after failed right‐­sided ablation

Ahmad Suhaimi Mustafa, Dicky Armein Hanafy, Muqsith Muhammad, Sunu Budhi Raharjo, Dony Yugo Hermanto, Yoga Yuniadi

National Cardiovascular Centre Harapan Kita, Indonesia

Introduction:

Radiofrequency ablation of atrioventricular nodal re‐­entry tachycardia (AVNRT) usually performed from the right ventricle side. In some cases, ablation was performed via LV side either antegrade or retrograde approached. We report a case of successful ablation of AVNRT retrogradely from left ventricle after failed ablation from right ventricle.

Methods:

A 54‐­year‐­old lady who had history of recurrent supraventricular tachycardia (SVT) underwent SVT ablation at our centre. Three venous access via right femoral vein and one right jugular vein were punctured. Two quadripolar catheters were placed at the His and right ventricular apex (RVA) while non irrigated ablation 4 mm tip 7F catheter at high right atria (HRA). Another decapolar catheter was advanced into coronary sinus (CS) via right jugular vein. The diagnosis of typical slow‐­fast AVNRT was made due to presence of sustained supraventricular tachycardia with tachycardia cycle length (TCL) of 320 milliseconds, A‐­H jump with echo, V‐­A‐­V pattern, post pacing interval (PPI) minus TCL more than 115 milliseconds and VA interval 30 milliseconds. Ablation catheter was used to map slow pathway potential area (Figure 1).

Result:

Multiple radiofrequency ablation (RFA) delivered at 20‐­30W, 50‐­60°C for 30 seconds with accelerated junctional rhythm seen. The tachycardia still inducible despite multiple ablation. Remapping and ablation of slow potential at coronary sinus (CS) ostium also failed to SVT. We decided to do mapping and ablation from left ventricular side. Right femoral artery puncture with 7F sheath inserted. IV heparin 5000u bolus was given. Ablation catheter was advanced retrogradely to the LV septal at the position opposite the His catheter and slightly caudal (Figure 2). Slow pathway potential was identified. Multiple RFA were delivered at 40W, 50C for 30 seconds and accelerated junctional rhythm were seen (Figure 3). Post ablation, SVT was not inducible with no A‐­H jump despite with aggressive atrial pacing and isoprenaline infusion.

Conclusion:

Ablation of AVNRT can sometime be challenging. Most often, successful ablation from right side yielded high successful rate. However, LV side ablation for AVNRT should be considered alternatively in cases where failed ablation from right side as in this case

FIGURE 1 Ablation of AVNRT from right slow pathway in RAO 30, 0 (right) and LAO 30, 0 (left)

FIGURE 2 Ablation done retrogradely from LV side, towards the LV septal in RAO 30, 0 (right) and LAO 30, 0 (left)

FIGURE 3 EGM showing slow potential documented from LV side (yellow arrow) during ablation followed by junctional rhythm. His signal was tagged from RV side

AP19‐­00927

Ebstein anomaly presenting with dual tachycardia: Successful ablation of both

Ahmad Suhaimi Mustafa, Dicky Armein Hanafy, Sunu Budhi Raharjo, Dony Yugo Hermanto, Muqsith Muhammad, Yoga Yuniadi

National Cardiovascular Centre Harapan Kita, Indonesia

Introduction:

Ebstein anomaly (EA) is a congenital cyanotic which present with enlargement of right atrium and displacement of tricuspid valve leading to atrialization of right ventricle. It is well associated with tachycardias including atrial flutter or fibrillation, atrioventricular nodal reentry tachycardia (AVNRT) and accessory pathway mediated tachycardia, and ventricular tachyarrhythmias. We presented a case of Ebstein anomaly presented with two tachycardias

Methods:

A 45‐­year‐­old lady who had Ebstein anomaly presented with 8 months history of dyspnea associated with palpitation. 12‐­lead electrocardiogram showed 2:1 counterclockwise atrial flutter with pre‐­excitation (Figure 1). Echocardiography showed ejection fraction of 65%, dilated right atrium with severe tricuspid regurgitation, mild pulmonary regurgitation and atrial septal defect secundum. We performed 3D mapping using Ensite system. Three right femoral vein punctures were done with two 7F sheaths for non‐­irrigated ablation and quadripolar catheter. One right jugular vein with 6F sheath for coronary sinus catheter. 3D mapping was done using ablation catheter to create right atrium (RA) geometry and local activation (LAT) mapping.

Result:

Using the ablation catheter which was placed at cavo‐­tricuspid isthmus (CTI) with atrial pacing showed post pacing interval minus tachycardia cycle length (PPI – TCL) <30 milliseconds indicating the atrial flutter was isthmus dependent. Activation mapping also showed counterclockwise atrial flutter. There was also earliest potential of 149 milliseconds was noted at the right posteroseptal area extending to the anterior of inferior vena cava (IVC) antrum with fused AV signal. We performed ablation at CTI using irrigating ablation catheter with SL1 sheath for better support at 30W, 45°C. During ablation of CTI line, there was also disappearance of delta wave followed by retrograde block. The ablation of CTI line was completed with termination of flutter.

Conclusion:

In our case, she had concomitant two tachycardias which were successfully ablated. Interestingly the accessory pathways located near the CTI line which susceptible to termination of AP during simultaneous flutter ablation.

AP19‐­00939

Ablation of a double‐­loop reentry in a giant right atrium

Fengyuan Yu, Qi Sun

Fuwai Hospital, China

Introduction:

A 33‐­year‐­old female was admitted for dyspnea on exertion for 6 years and palpitation for 2 years, with the history of idiopathic pulmonary hypertension. She took regular beraprost, sildenafil and the dyspnea was controlled until palpitation began 2 years ago. Electrocardiogram showed atrial flutter with complete right bundle branch block and electrical cardioversion was usually needed. Amiodarone was increasingly dosed, while palpitation grew more and more frequent. Echocardiography revealed a giant right atrium, both the anterior to posterior diameter and the anterior to posterior diameter of which was 88 mm, and estimated systolic pulmonary pressure was 95 mm Hg.

Methods:

After atrial thrombus was eliminated on CT scan and anticoagulation administered, the electrophysiological test began and electroanatomic, activation, and entrainment mapping were employed.

Result:

Electroanatomic mapping displayed a giant right atrium with a volume >500 mL. Double potentials were found on upper crista terminalis and vertical linear dense scars on the right posterior atrial free wall with gaps. Cycle length gained in mapping the right atrium exceeded 90% of that of the tachycardia (TCL 354 milliseconds). Activation and entrainment mapping revealed a cavotricuspid isthmus (CTI) dependent atrial flutter. On ablating the CTI, TCL suddenly prolonged to 430 milliseconds and the atrial activation changed on coronary sinus (CS) leads. Remapping found a new reentry passing through the gap within scars. Ablation towards the gaps terminated the tachycardia and lesion lines were extended from the lower end of scars to the inferior vena cava. Bidirectional block was confirmed for the two ablation lines. Amiodarone was gradually decreased and dyspnea relieved.

Conclusion:

Dense scars on right atrial free wall could result from atrial remodeling in response to pulmonary hypertension. Like vertical surgical incisions, gaps in scars could give rise to double‐­loop reentry, which could be terminated by radiofrequency ablation.

FIGURE 1 Chest X ray and CT on the level of right atrium

FIGURE 2 Atrial flutter on electrocardiography

FIGURE 3 Gap in the vertical dense scars

FIGURE 4 Entrainment supported double‐loop reentry

AP19‐­00970

The manifestation of the accessory pathway by inhibiting the conduction of atrioventricular node using an ultra‐­short‐­acting intravenous beta‐­1 adrenergic blocker

Takahiko Kinjo, Masaomi Kimura, Shingo Sasaki, Daisuke Horiuchi, Taihei Itoh, Kimitaka Nishizaki, Yuichi Toyama, Hirofumi Tomita

Hirosaki University Graduate School of Medicine, Japan

Introduction:

When mapping the atrial insertion site of an accessory pathway (AP) is performed during ventricular pacing, a fusion of atrial activation caused by retrograde conduction of both atrioventricular node (AVN) and AP should be differentiated. In order to map atrial insertion site during ventricular pacing, dissociation of retrograde conduction of AP from that of AVN is required and may be achieved with ventricular extrastimulus or pharmacologic block. We hypothesized that differentiation of retrograde conduction of AP from that of AVN can be achieved by using the ultra‐­short‐­acting intravenous beta‐­1 adrenergic blocker, landiolol.

Methods:

This study was a prospective, single‐­center, interventional, non‐­randomized study. In this study, we enrolled 15 years old or older patients who admitted to Hirosaki University Hospital between October 2017 and July 2019 for radiofrequency catheter ablation (RFCA) of paroxysmal supraventricular tachycardia (PSVT). After the electrophysiologic study, patients who diagnosed as orthodromic atrioventricular reciprocating tachycardia (ORT) using an accessory pathway were included in this study.

Result:

We enrolled 18 patients who underwent RFCA for ORT. Retrograde conduction over AVN was not detected in 12 patients after landiolol administration. In the remaining 6 patients, effective refractory period (ERP) and retrograde conduction time of AP and AVN were measured both at baseline and after landiolol administration (10 μg/kg/min). ERP of AP was unchanged after landiolol administration (273 ± 30 vs 273 ± 23 milliseconds, P = .99), whereas that of AVN tended to prolonged (366 ± 120 vs 438 ± 191 milliseconds, P = .08). Conduction time of AP was not affected by landiolol (138 ± 40 vs 137 ± 37 milliseconds, P = .75), whereas that of AVN was significantly prolonged after landiolol (168 ± 64 vs 189 ± 65 milliseconds, P = .008). In three patients, the fusion of atrial activation caused by retrograde conduction of both AVN and AP was observed during ventricular pacing. In these patients, ventricular pacing rate manifesting the conduction over AP was 30 ppm lower after landiolol administration, whereas it was unchanged in the other patients. RFCA of AP under landiolol administration was successfully done in all patients. During a follow‐­up of 14.6 ± 6.2 months, no recurrence was detected.

Conclusion:

Our preliminary data showed that landiolol prolonged conduction time of AVN without affecting AP, and may be useful in the manifestation of the AP conduction.

AP19‐­00972

Good recovery of left ventricular function after Nodo Hisian catheter ablation in Wolff‐­ Parkinson‐­White syndrome

Evan Kurniawan, Giky Karwiky, Mohammad Iqbal, Chaerul Achmad, Mohammad Rizki Akbar, Januar Wibawa Martha

Department of Cardiology and Vascular Medicine, University Padjadjaran affiliated Hasan Sadikin Gene, Indonesia

Introduction:

Manifest accessory pathway (AP) located in the Nodo Hisian (NH) region around the Atrioventricular Node (AVN) are rare and poses challenges for ablation strategy since ablation in this case is associated with risk of Atrioventricular (AV) block. Here we present a rare case of symptomatic Wolff‐­Parkinson‐­White (WPW) syndrome with NH AP and deterioration of left ventricular ejection fraction (LVEF) who underwent succesful AP ablation.

Methods:

A 19‐­year‐­old woman presented to local hospital with palpitation and dyspnea for several hours. The electrocardiography (ECG) showed a supraventricular (SVT) rhythm with a heart rate of 201 beats per minute. She was then treated with intravenous amiodarone but failed to convert to sinus rhythm and finally did convert with cardioversion after 48 hours. The ECG showed sinus rhythm and delta wave. Echocardiography showed dilation of all cardiac chambers with LVEF 50%, which was a significant deterioration than normal echocardiography 3 months ago. She was then scheduled for ablation and electrophysiology study showed eccentric activation during sinus with earliest V at septal area and fused A and V wave on His catheter. Retrograde conduction of AP also at the same area. We then performed a slowly uptitrated dose of radio frequency catheter ablation (RFCA) at the tricuspid annulus right in front of the His Bundle. The procedure was successful with no complication and the tachycardia could not be induced anymore afterwards. The next day ECG showed no delta wave and subsequent echocardiography showed the cardiac chambers and LVEF returned to normal.

Result:

For this case, we used a recently proposed maximal pre‐­excitation based algorithm and showed accurate location based on surface ECG. Risks with ablation strategy for NH AP can be minimized with use of different techniques such as placement of the catheter on the tricuspid annulus more at the ventricular insertion and lower RF power. We used RFCA placed on the tricuspid annulus at the ventricular insertion with careful slowly uptitrated dose and produced a good result with no complication. Significant deterioration of LVEF in this case could be caused by NH dyssynchrony considering the presence of NH AP. However, the patient suffered an episode of tachycardia for almost 48 hours and we thought was the main factor contributing to LVEF deterioration. Furthermore, after successful ablation, echocardiography showed the return of LVEF after 10 days confirming our theory.

Conclusion:

This report showed that catheter ablation of WPW syndrome with NH AP could be performed safely and resulted in good recovery of LVEF.

FIGURE 1 ECG during tachycardia

FIGURE 2 ECG after sinus rhythm

FIGURE 3 ECG after ablation

FIGURE 4 EP study catheter placement

AP19‐­00986

Efficacy and safety of radio frequency ablation for atrial flutter at single center in Vietnam

Anh Hoang Nguyen

Tam Duc Heart Hospital, Vietnam

Introduction:

Radio frequency ablation (RFCA), recently becomes one of the most effective treatment for atrial flutter patients who do not either respond to medical treatment. However, there are insufficient studies in Viet Nam about treatment outcomes after performing ablation. Therefore, the aim of our study is to assess efficacy and safety of RFCA for managing atrial flutter at Tam Duc Heart Hospital.

Methods:

Between December 2013 and July 2019, twenty‐­three patients underwent ablation of atrial flutter at Tam Duc Heart Hospital. Pre‐­ablation transoesophageal echocardiography were performed for excluding intracardiac thrombus. During post‐­ablation follow up period, majority of patients received oral anticoagulation and antiarrthymic medications for at least one month, depending on individual thromboembolism and bleeding profiles. Recurrence of atrial flutter was assessed by symptoms, ECG, or Holter ECG.

Result:

A total of 23 patients entered our study, 19 of whom have typical atrial flutter and the rest having atypical atrial flutter. The majority in our study is male patients; the mean CHA2S2D‐­VaSc score is 1.9 and the mean HAS‐­BLED score is 0.7. After the mean follow up of 25.7 months, 74% (17/23) of patients were free of symptom during follow up. Recurrence rate are 25% (1/4) for atypical atrial flutter group, while the number is 26% (5/19) for typical atrial flutter. Among these patients which have atrial flutter recurrence, only one patient underwent re‐­ablation with completely success. Following ablation, only two patients developed atrial fibrillation. Only one femoral hematoma was reported as complication in our study.

Conclusion:

Our study illustrates same results as many previous studies about atrial flutter ablation. In a selected group of patients with atrial flutter, catheter ablation could be considered as first‐­line therapy because of its efficacy and safety, low recurrence and complication rate.

AP19‐­00987

Case report: Atrial fibrillation on Wolff‐­Parkinson‐­White syndrome cause heart failure

Long Vien Hoang

Bach Mai Hospital, Vietnam

Introduction:

A 48 years ‐­ old male patient had been diagnosed atrial fibrillation on WPW syndrome. He could not be converted to sinus rhythm for ablation with cardio‐­version and had been prescribed amiodarone 200 mg once a day for 6 months. After 6 months, the rhythm still was atrial fibrillation with wide QRS, the patient felt tired, difficult to breath. Echo showed EF was 18% and patient's hand was cold and wet. The patient underwent emergency EPS for ablation. After 1 hour, we ablated successfully the accessory pathway while atrial fibrillation.

Methods:

Case report.

Result:

Next day, patient got echo and EF increased to 36% (still atrial fibrillation). After three months, the EF came back to normal with optimal treatment.

Conclusion:

Atrial fibrillation on WPW syndrome cause heart failure rapidly. Sometimes we need to do ablation while atrial fibrillation if we cannot convert to sinus rhythm.

AP19‐­00998

Case report: Multi accessory pathways: endocardial and epicardial

Thuy Nguyen Thi Le

Bach Mai Hospital, Vietnam

Introduction:

A 44 years ‐­ old male patient had been diagnosed WPW syndrome. He underwent to cath lab for electrophysiology study and ablation. The 12 lead ecg suggested an type A Wolff – Parkinson – White syndrome with left lateral pathway. We induced an narrow QRS tachycardia, the earliest atrial activation is on CS distal (same as A‐­V fusion wave on sinus rhythm). After successful ablation on CS distal, another tachycardia appeared which got different sequence in CS (the earliest atrial activation is on CS 7‐­8, but not fusion).

Methods:

Case report.

Result:

We tried many time from left ventricular endocardial but not success. We tried approach via coronary sinus vein and stopped the tachycardia after 2 seconds. No more delta wave after ablation from CS.

Conclusion:

There were both endocardia and epicardia pathway in a patient is very rare but still.

AP19‐­01006

Multiple accessory pathways ablation in pediatric patient with double AV discordance post Glenn shunt surgery

Ngoc Phan

Tam Duc Hospital, Ho Chi Minh City, Vietnam

Introduction:

The patient was 8 years old girl having history full‐­term of birth, cesarean delivery. She was discovered congenital heart disease at 5 months old with diagnosis of Double discordance—ASD, VSD—Pulmonary atresia. She had operation at our hospital in 2012 (BT shunt) and in 2015 (Glenn shunt and PA enlargement). Since 7 years old, she's had several episodes of tachycardia, each lasted about 15‐­30 minutes and terminated spontaneously. Few months later, the tachycardia became more frequent. During tachycardia (HR 210‐­220 bpm), she had symptoms of dyspnea, sweating, increased cyanosis. So she had to admitted to hospital with note of hypotension. The supraventricular tachycardia (SVT) was diagnosed and terminated with Amiodarone IV. She was received medical management with Amiodarone 100 mg/d + Propranolol 50 mg/d (or Bisoprolol 5 mg/d). Unfortunately her SVT was refractory to medication and she had indication for ablation of symptomatic SVT.

Methods:

Procedure Baseline rhythm was sinus rhythm with normal AH, HV interval. No delta wave was noted. For safety we created geometry of right and left atrium with marked sinus node area and His bundle using Ensite system. Antegarde conduction was through main pathway with no dual physiology AV node was noted. Retrograde conduction was through main pathway and concealed accessory pathways (left posterior lateral and left free wall). SVT initiated easily with burst pacing from CS, ventricular extra‐­stimulus S1S2 or burst pacing from ventricle. During SVT her hemodynamic was unstable with very low blood pressure (52/20 mmHg). Clinical characteristics SVT were narrow QRS, tachycardia cycle length (CL) 281 ms, eccentric atrial activation with earliest atrial activation at CS 3‐­4. Ventricular pacing entrained SVT with Post pacing interval 62 ms, VAV response which suggested mechanism of this SVT was orthodromic AVRT through conceal left posterior lateral accessory pathway (AP). We approached left atrium through the ASD and ablated left posterior lateral AP. During ablation, the A activation changing from CS 3‐­4 to CS 5‐­6, the orthodromic AVRT continued with same CL. We suspected that she had oblique AP. Another pulses were targeted at CS 5‐­6 which could successfully terminate SVT within 4 seconds. After ablation we couldn't initiate this clinical AVRT. The other non‐­ sustained AVRT through conceal left free wall AP could be initiated spontaneously. We targeted the left free wall AP and successfully ablated this AP within 2.5 seconds. After ablation, no tachycardia could be induced in 45 minutes. The antegrade conduction was through main pathway, ventriculoatrial dissociation was at V pacing CL 490 milliseconds. The case was closed safely without any complication.

Result:

Successfully ablated multiple AP.

Conclusion:

The advent of technologies and understanding of arrhythmia mechanism, has helped us to ablate successfully this case.

AP19‐­01023

Incidence, clinical and electophysiological characteristics and outcomes of patients with Wolff‐­Parkinson‐­White syndrome and atrial fibrillation

Debasis Acharya, Shomu Bohora

U N Mehta institute of cardiology, India

Introduction:

Atrial fibrillation associated with preexcitation is life threatening. Our study aimed to characterise the incidence, clinical features electrophysiologic characteristics and outcomes of patients presenting atrial fibrillation with fast ventricular rates associated with an accessory pathway

Methods:

This is a both retrospective and prospective study. Retrospective data over 10 year and prospective data for 1 year was collected. Out of 2876 patients undergoing electrophysiologic study, 320 patients had manifest preexcitation on ECG. Patients who had presented with atrial fibrillation and fast ventricular rates were included in the study.

Result:

Out of 320 number of patients had manifest preexcitation on ECG, 41 (12.8%) presented with Atrial fibrillation and fast ventricular rates. Mean age of presentation is 38.5 ± 12.3 years 29 (72.5%) are male. Most common presenting feature ware palpitations, presyncope and syncope. 28 (71.09%) patients required cardioversion for treating the presenting episode. Two patients who had narrow complex tachycardia and were given adenosine developed atrial fibrillation and fast ventricular rates and have to be cardioverted. Systemic amiodarone was effective in 11 (28.9%) patients. Most common pathways involved in WPW(Wolff‐­Parkinson‐­White) syndrome with AF (Atrial fibrillation) are right poster septal (33.33%) followed by coronary sinus epicardial (22.92%). Five (12.19%) patients had multiple pathways. CS diverticulum was seen in six (14.65%) patients. Ablation was required to be done during atrial fibrillation in six (14.65%) patients. All had immediate successful ablation except one. One patient had a recurrence of preexcitation on follow up and successfully ablated during redo procedure.

Conclusion:

Atrial fibrillation with WPW syndrome is common and seen in 12.8% of all patients with preexcitation. It is common in middle aged male and in posteriorly located accessory pathways. It is also commonly associated with CS diverticulum and multiple pathways. Radiofrequency ablation has good outcomes.

AP19‐­01027

Coronary sinus diverticulum‐­related accessory pathway: Ablation via internal jugular approach

Debabrata Bera, Calambur Narasimhan, Suchit Majumder, Sanjeev Mukherjee

Rabindranath Tagore International Institute of Cardiac Sciences, India

Introduction:

Postero‐­septal accessory pathways (PSAP) can occasionally be present within coronary sinus diverticulum (CSD) posing difficulties during catheter ablation.

Methods:

Among failed PSAP cases, CSD is found in nearly half of them. We present a 30‐­year‐­old lady with PSAP (with QS in lead 2) with orthrodromic re‐­entrant tachycardia and history of prior failed ablation.

Result:

Left coronary angiogram during levophase revealed a large CSD. The anatomy of the CSD was very difficult to engage via femoral approach despite trying multiple catheters and different steerable sheaths.

Conclusion:

A superior approach form right internal jugular vein provided an easier access with stable contact leading to successful PSAP ablation. Although subclavian approach has been occasionally reported, this is the first report of internal jugular approach which is likely to work better in cases with upward looking CS os like our case.

AP19‐­01032

Shortening of fast pathway effective refractory period post successful ablation of atrioventricular nodal re‐­entrant tachycardiaA

Iyan Soihin, Doni Yugo Hermanto, Sunu Budhi Raharjo, Dicky Armien Hanafy, Yoga Yuniadi

National Cardiac Center Harapan Kita Jakarta, Indonesia

Introduction:

Atrioventricular nodal re‐­entrant tachycardia (AVNRT) is the most common supraventricular tachycardia (SVT). Catheter ablation is the preferred therapeutic strategy for this arrhythmia with high successful rate. The purpose of this study is to report the clinical and electrophysiological characteristics of our AVNRT ablation.

Methods:

This was an analytic observational study with a cross sectional design. Sample was obtained by medical record review study which fulfilled the inclusion and exclusion criteria. Subject who were included were those with AVNRT induced by extra stimulus pacing, while those requiring study drug were excluded. Data was shown as numerical value (mean±SD) and tested using either Pearson's or Spearman's test with P value of ≤.05.

Result:

During the period of January–December 2018, we collected data from 63 patients. Majority of patients were female (76.19%), the mean age was 44.2 ± 15.1 years old. The successful rate of typical AVNRT ablation was 97.5%. Interestingly, we found a shortening of the effective refractory period (ERP) of the AVN fast pathway (FP) post slow pathway ablation (pre‐­ablation: 340.48 ± 64.97 milliseconds; post ablation: 269.84 ± 51.54 milliseconds, P < .05).

Conclusion:

We found a shortening of the ERP of the AVN fast pathway post slow pathway ablation. Whether this phenomenon is related to the success rate of the ablation need further studies.

AP19‐­01040

Left posterolateral Mahaim like accessory pathway

Ramdeo Yadave

Batra Hospital, India

Introduction:

Twenty five year old male presented recurrent palpitations with ECG showing Regular wide QRS tachycardia with RBBB and Left axis deviation with V1 to V6 positive .Left posterolateral origin of tachycardia. DC cardioversion was done. Echo showed structurally and functionally normal heart. Taken up for EPS and RFA.

Methods:

EP study showed only antegradely conducting pathway with maximum preexcitation near C5,6 and pacing C5,6 in decapolar catheter showed maximum preexcitation. On V‐­pacing from RV apex conduction was concentric and decremental which exclude retrograde conduction through the pathway. We paced LV lateral wall which also confirmed retrograde conduction through the AV node. This confirms pathway is only antegrade conducting. On A ‐­Pacing AV interval increases on progressive Preexcitation at shorter CL on atrial extra beat suggestive of decrementally conducting pathway.

Result:

By Transeptal route successful RF ablation done in Left posterolateral region while pacing C5,6 diapole with maximum preexcitation and earlier V than delta wave with loss of preexcitation

Conclusion:

This 25 year old male having regular wide QRS tachycardia with RBBB and Left axis deviation and V1 to V6 positive concordance suggestive of left posterolateral VT or Preexcited tachycardia. But Preexcitation in baseline suggestive of Preexcited tachycardia. Maneuver done to exclude retrograde conduction of pathway. Atrial pacing suggestive of decremental antegrade pathway with Mahaim like properties. By transeptal route successful RF ablation done with loss of Preexcitation. Over 4 months of follow up no recurrence of pathway or tachycardia.

AP19‐­01059

Novel 48‐­bipole configuration of a grid‐­style mapping catheter: How does this affect substrate mapping compared to the standard, manufacturer‐­recommended configuration?

Hooi Khee Teo, Kelvin Chua, Kah Leng Ho, Boon Yew Tan, Daniel Chong, Shufen Liang, Paul Chun Yih Lim, Vern Hsen Tan, Colin Yeo, Kelvin Cheok Keng Wong, Loo Chin Wong, Carlo Peter Tan, Murphy Zhiyuan Liu, Chi Keong Ching, Eric Lim

National Heart Centre, Singapore

Introduction:

Substrate maps (SMs) are often acquired during ablation of complex arrhythmias. An important limitation of SM is that recorded voltages are affected by orientation of the electrode bipole with respect to activation wavefront direction, so SMs may not truly reflect voltage properties of the underlying substrate. Recently, a multi‐­electrode catheter utilizing a grid design was introduced; this was designed for use in conjunction with a software algorithm where each electrode is part of ≥ 2 bipolar configurations, and the annotated voltage for that electrode would be the highest recorded value for all configured bipoles. In theory, this should reduce dependence of SM voltage on wavefront direction. In this study, we explore the effect of different bipole configurations on recorded SM.

Methods:

We retrospectively analysed SM acquired using the Abbott HD Grid/ESI Precision mapping system. Each map was re‐­processed using 4 different Grid configurations through the ESI Turbomap feature – (a) horizontal 12 electrogram (EGM) “H12” (b) vertical 12 EGM “V12” (c) manufacturer‐­recommended ‘HD Wave’ 18 EGM “HD18” and (d) a custom 48 EGM configuration “HD48”. Peak‐­to‐­peak voltage data for each was then exported from the mapping system. Percentage of EGMs falling into conventional scar/border zone/healthy tissue thresholds were calculated (0.1‐­0.5 V for atrial and 0.5‐­1.5 V for ventricular cases).

Result:

SM of 55 tachycardias from 36 patients were analysed (473625 atrial, 161630 ventricular mapping points). Mapped chambers were RA (18), LA (24), LV (7), RV (3), epicardium (3). Mapped rhythms were AF (8), AFLU (26), sinus (10), atrial pacing (5), ventricular pacing (6). Mean voltage of each atrial point was not different between H12 and V12 (0.73 V for both). However, both HD18 and particularly HD48 configurations showed increased voltages—0.83 V and 1.01 V respectively, corresponding to a 13.7% and 38.4% increase over H12. Mean voltage of the HD48 configuration was 21.7% higher than for HD18. Mean voltage for each ventricular point steadily increased from 2.12 V (H12), 2.42 V (V12, 14% increase over H12), 2.63 V (HD18, 24.1% increase over H12) to 3.29 V (HD48, 55.2% increase over H12). Mean voltage of the HD48 configuration was 25.1% higher than for HD18.

Conclusion:

We confirm that directionality is an important effect when acquiring SM. We show this effect is reduced when using a grid‐­design catheter coupled with a novel software algorithm. We also show that a custom HD48 configuration is able to record even higher voltages than the manufacturer‐­ recommended HD18 configuration. The increase in voltage is significant (21.7% for atrial and 25.1% for ventricular SM) and can affect clinical interpretation of SM. We conclude that use of HD48 for SM may be preferable compared to HD18 and deserves further study.

AP19‐­01066

Normal resting ECG as a predictor of accessory pathway in Ebstein's anomaly, and tips for ablation

Doni Friadi, Adrianus Akbar, Ekiy Setiyawan, Gugun Iskandar Hadiyat

Hasna Medika Cardiovascular Hospital, Indonesia

Introduction:

Ebstein's anomaly (EA) is a congenital heart disease characterized by low implantation of tricuspid valve and commonly associated with Right Bundle Branch Block (RBBB) pattern contributing to nearly 1% of all congenital heart lesions. Around 30% of EA population may have pre‐­ excitation, ablation of accessory pathway (AP) in EA is quite difficult because of anatomy abnormality. In this report, we aim to show In EA condition, the absence of RBBB may predict the presence of accessory pathway and several approaches for AP ablation in EA.

Methods:

—

Result:

We present two cases identified with EA and manifested with episodes of supra‐­ventricular tachycardia (SVT). The clinical findings and ablation sites are reported. All 2 cases presented with normal resting ECG with absent RBBB and narrow complex tachycardia with RBBB‐­like morphology. Case 1 showed resting ECG with sinus rhythm and minimal pre‐­excitation with no RBBB pattern. The tachycardia episodes were QRS complex with RBBB‐­like pattern and superior axis, case 2 showed a resting ECG with absent of pre‐­excitation and no RBBB. The tachycardia episodes showed QRS complex with RBBB‐­like pattern and normal axis. Detailed mapping revealed an accessory pathway located in the right posteroseptal region. Mapping during sinus rhythm showed the shortest AV time at the 6 to 7 o'clock position in the 30 left anterior oblique view. Programmed extra‐­stimuli showed no evidence of a decremental conduction in both cases. Because of anatomical variation in EA, RCA angiogram was performed to locate tricuspid annulus. Femoral approach was used to ablate the accessory pathway in case 1. However, in case 2 after failed inferior approach, ablation procedure was performed from the jugular vein access for catheter stability. During radiofrequency energy application, the 12 lead ECG changed to a complete RBBB which is a classic finding in EA. No tachycardia was inducible after ablation in both cases.

Conclusion:

Concealed AP may manifest with normal resting ECG in EA patients. The RBBB pattern was revealed after AP ablation. In difficult cases, RCA angiogram could be performed to locate the tricuspid annulus and jugular vein approach may be an alternative for catheter stability during ablation.

AP19‐­01080

Co‐­existance of atrioventricular nodal re‐­entrant tachycardia and idiopathic left ventricular tachycardia

Lalaj Ruchiranga Sembakuttige

National Hospital of Srilanka, Sri Lanka

Introduction:

Simultaneous occurrence supraventricular tachycardia and ventricular tachycardia is a rare phenomenon named as double tachycardia. In clinical practice, Atrioventricular Nodal Re‐­entrant Tachycardia (AVNRT) and idiopathic left ventricular tachycardia (ILVT) are electrocardiographically indistinguishable because AVNRT sometimes conduct with a right bundle branch block causing wide complex tachycardia similar to ILVT.

Methods:

A 34 year old male presented with palpitation and presyncope which was associated with electrocardiographic evidence of frequent ventricular extra systoles, and episodes of non‐­sustained ventricular tachycardia originated from left fascicular region. Subsequently, he underwent VT stimulation and comprehensive SVT study. Both atrial extra stimulation and ventricular stimulation induced AVNRT and ILVT with two distinct cycle lengths and electrophysiological characteristics.

Result:

The patient was symptomatically improved after successful radiofrequency ablation of both ILVT and AVNRT simultaneously.

Conclusion:

Dual atrioventricular nodal physiology appears to be associated with ILVT. Therefore, it is worthwhile to undergo a complete electrophysiological evaluation in patients with ILVT.

LAO fluoroscopic view during RF ablation of slow pathway of AVNRT

LAO fluoroscopic view during RF ablation of ILVT

Electrocardiographic recordings of ILVT

Intra‐­cardiac signals of induced AVNRT

AP19‐­01088

Rare accessory pathway between giant left atrial appendage and left ventricle

Hisaaki Aoki

Osaka Women's and Children's Hospital, Japan

Introduction:

An accessory pathway (AP) between left atrial appendage (LAA) and left ventricle (LV) is rare and only 14 cases have been reported. It features a potential of ventricular fibrillation due to short effective refractory period (ERP) of the AP, coexistence of multiple APs or an AP between right atrial appendage and right ventricle, and difficulty of endocardial ablation. We reports a 6‐­year‐­old boy with multiple APs including LAA‐­LV AP, a giant LAA, and noncompaction of LV (NCLV). Little has been reported on LAA‐­LV AP associated with a giant LAA.

Methods:

N/A

Result:

Case summary A 6‐­year‐­old boy presented with WPW syndrome in a school cardiac screening. The Holter ECG exhibited a PSVT at 279 bpm. The echocardiogram revealed a NCLV with ejection fraction of 69% and none of mitral regurgitation. The catheter ablation was performed under general anaesthesia in 6 years old. EPS exhibited several kind of delta waves, the effective refractory shortest period of the APs was 200 milliseconds. The multiple APs were ablated at left anterior, left lateral, left posterior, and right postero‐­lateral via transseptal, retrograde, and inferior vena cava. However all the delta waves were not eliminated. A second session was performed at the age of 8 years old. A computed tomography exhibited a giant LAA of 12.9 ml/m2 (normal 6.32 ± 2.67 1). The ECG exhibited ventricular pre‐­ excitation in all beats and a different QRS morphology during PACs. The morphology of delta waves during sinus rhythm suggested right sided AP, whereas those during PAC suggested a left anterior AP. In the session, a 2 Fr steerable catheter was positioned to the distal of CS (anterior interventriular vein) in addition to the catheters in the first session. The earliest ventricular activation site during sinus rhythm was at the distal electrode of the CS catheter, which was near the LAA according to the angiography of the left atria. Though we could not ablate the APs along the mitral annulus during the 1st session, we successfully ablated the AP using a 4‐­mm non‐­ irrigated catheter at the base of the LAA. ST changes did not occur during delivering RF energy. The distance between the successful ablation site and mitral annulus was 9 mm. Then we successfully ablated 3 other APs near the CS ostium and on the right lateral and postero‐­lateral sides of the tric

Conclusion:

We reports a 6‐­year‐­old boy with multiple APs including LAA‐­LV AP, a giant LAA, and NCLV. A LAA‐­LV AP should be suspected in tough case in left sided AP and a CT help us to diagnose it.

AP19‐­01156

Catheter ablation of a right atrial appendage to right ventricular connection

K. Kotti, Jaya Pradhap, B. Radhika, S. Aishwarya, S. Sabari, Mahima P. Manoj, G. Nithin, G. Sailendri, S. Benjamin, Ravi Kumar, S. Nirmala, Dasari Himaja, S. Sandini, K. Swathi, Ulhas M. Pandurangi

The Madras Medical Mission, India

Introduction:

An atrial appendage to ventricular accessory pathways are uncommon. It can be congenital or acquired (surgically created). The epicardial approach may be required for the successful ablation of such a pathway due to the epicardial course. We report a successful ablation of a rare case of ‘epicardial accessory pathway’ (AP) connecting the right atrial appendage (RAA) to the right ventricular outflow tract (RVOT).

Methods:

A 19‐­year‐­old boy with dysmorphic facies, cleft palate, pectus excavatum, mental retardation and a structurally normal heart presented with recurrent palpitations and a history of failed RFA. The 12‐­lead sinus rhythm ECG was suggestive of ventricular pre‐­excitation. An orthodromic AVRT was reproducibly inducible. Maximal pre‐­excitation by atrial pacing suggested right free wall anteriorly located AP.

Result:

Extensive mapping, with the aid of fluoroscopy and 3‐­D electro‐­anatomic imaging, along the tricuspid annulus during maximal preexcitation and AVRT did not yield satisfactory A‐­V potentials. Mapping was also performed in the coronary aortic cusps. Mapping within the right atrial appendage (RAA) yielded the most satisfactory signals including sharp AP potentials. The RAA anatomy was diligently defined using angiogram and 3‐­D mapping. RF lesions (40 W; 43°C; 8 seconds) during sinus rhythm resulted in the separation of A‐­V potentials and loss of pre‐­excitation. Overdrive atrial and ventricular pacing demonstrated absence of AP. There was no inducible tachycardia. At 6‐­month follow‐­ up, there was no recurrence. The location of the successful site of ablation is indicative of congenital epicardial A‐­V connection, atrial appendage being the atrial end and adjoining right ventricular outflow tract as the ventricular end.

Conclusion:

One should suspect atrial appendage to ventricular connections if preexcitation shows QS pattern in V1 & V2 and inferior axis in limb leads especially in a case of previously attempted RF ablation

AP19‐­01160

A case of Ripple mapping in postoperative atrial tachycardia in patient with mitral valve surgery and Cox‐­Maze IV procedure

Chi Cai

Fuwai Hospital, National Center for Cardiovascular Diseases, Peking Union Medical College & Chinese, China

Introduction:

Atypical macroreentrant atrial arrhythmia (AT) is frequently related to a history of open heart surgery, which has become an increasingly prevalent arrhythmia in many patients. However, its diagnosis as well as catheter ablation remains a challenge. In this report, we present a unique case of a macroreentrant atrial tachycardia involving the mitral annulus (MA), which developed after surgical intervention for a mitral valve replacement and catheter ablation of typical atrial flutter.

Methods:

We herein report a case of a 56‐­year‐­old man with rheumatic heart disease and atrial fibrillation underwent simultaneous mechanical mitral valve replacement and tricuspid valve repair with concomitant modified Cox‐­Maze IV procedure. After 2 years of open heart surgery, the patient underwent a percutaneous cavotricuspid isthmus (CTI) catheter ablation procedure because of typical atrial flutter. And the patient had a recurrence of atrial tachycardia after 10 months of CTI ablation and required repeat procedure. Ripple mapping of the left atrial (LA) and right atrial (RA) was performed to identify the correct target for ablation.

FIGURE 1 Ablation lines after Cox‐Maze IV procedure and catheter ablation of typical atrial flutter

FIGURE 2 The Ripple mapping showed the single‐loop macroreentrant circuits using the MA and implied the presence of the slow conduction in the mitral isthmus

FIGURE 3 Continuous linear radiofrequency catheter ablation of the mitral isthmus was performed, resulting in cycle length prolongation and termination to sinus rhythm

Result:

The Ripple mapping showed the single‐­loop macroreentrant circuits using the MA and implied the presence of the slow conduction in the mitral isthmus, where the activation wavefront arised from MA going along the anterior wall of the LA, subsequently turning over the RA septal and extending toward the proximal to distal in the CS opposite of posterior wall of MA in counter‐­clockwise rotation. Continuous linear radiofrequency catheter ablation of the mitral isthmus was performed, resulting in cycle length prolongation and termination to sinus rhythm. Bidirectional block across the mitral isthmus was achieved and noninducibility of any SVT was confirmed by burst atrial pacing after tachycardia termination.

Conclusion:

Previous studies have shown that, in patients with prior MV surgery and regular ATs, macroreentry is the predominant arrhythmia mechanism. Ripple mapping identified the correct target for ablation with high diagnostic confidence in a case of complex AT after heart surgery.

AP19‐­01162

Epicardial atrial connections causing failure to block linear ablation lesions: A single center experience

Rilong Hong, Kelvin Chua, Kah Leng Ho, Boon Yew Tan, Paul Chun Yih Lim, Daniel Chong, Shufen Liang, Wee Siong Teo, Chi Keong Ching, Eric Lim

Singhealth, Singapore

Introduction:

In cases of atrial flutter, inability to block linear ablation lesions is an important cause of ablation failure. A proportion of such failures is believed to be due to epicardial atrial connections, but this type of connection is poorly described in the literature. We report our center's experience.

Methods:

We retrospectively reviewed atrial flutter cases treated with a linear lesion in either right or left atrium, looking for failure to block a linear ablation lesion. In all cases, 3D mapping system was used (Rhythmia HDx, BSc; CARTO 3v4, BW; ESI Precision, Abbott Medical). We defined endocardial block as clear demonstration of wavefront propagation proceeding exclusively towards the ablation line. Correspondingly, an epicardial connection was proposed when there is a focal breakout beyond a line of endocardial block (either during pacing, or during tachycardia). We defined and presumed endo‐­ epicardial block once the focal breakout distal to the linear lesion was abolished. Termination of tachycardia alone was not deemed sufficient evidence of endo‐­epicardial block. Entrainment was used as necessary to confirm the impression of a re‐­entrant endo‐­epicardial circuit.

Result:

7 cases were identified (3% of all patient cases during the review period; table). 2 involved the right atrial cavotricuspid isthmus. One was a short connection crossing the cavotricuspid isthmus, and one was a very long connection arising from the lateral RA and connecting near the right septum at the roof of the coronary sinus. Five cases involved the left atrium. Four were mitral‐­isthmus (MI) dependent. Two were ablated successfully within the CS but away from the endocardial MI‐­line, at the site of epi‐­endocardial connection. Two were ablated successfully at the site of epi‐­endocardial connection but this time at the endocardial end. One occurred in a post‐­atrial fibrillation ablation patient with a roof line; epi‐­endocardial exit was identified anterior to the roof line.

Conclusion:

Epicardial connections in the atrium can cause failure to achieve a line of block. They appear to be uncommon but may well be under‐­recognized. They should be suspected when: (a) endocardial block can be demonstrated by wavefront propagation towards the ablation line, (b) despite which there is either failure to terminate the tachycardia or achieve an adequate timing interval across the line when pacing near one side of the line. Usually the distal (epi‐­endocardial) connection appears near the line of block but rarely, the connection can be long and >2 cm away from the line—in such cases, a high index of suspicion is required as the activation map can then appear confusing. We show that careful endocardial mapping aids the recognition of epicardial connections and focal ablation at the site of endo‐­epicardial breakthrough (which may be distant from the ablation line itself) is usually sufficient to completely block the ablation line.

Atrium	Flutter circuit	Epicardial connection	Mapping system	Successful ablation site
Right	CTI‐­ dependent	Epi‐­endo breakout: Just lateral to CTI in 6 o'clock position	CARTO 3v4	Epi‐­endo breakout site
Right	CTI‐­ dependent	From lateral RA to right mid‐­ septum	ESI Precision	Endo‐­epi entry site
Left	MI‐­ dependent	Across the mitral isthmus	Rhythmia HDx	Endocardial aspect of the epi‐­endo connection
Left	MI‐­ dependent	Across the mitral isthmus	Rhythmia HDx	Endocardial aspect of the epi‐­endo connection
Left	MI‐­ dependent	Across the mitral isthmus	CARTO	Epicardial (CS) aspect of the epi‐­endo connection
Left	MI‐­ dependent	Across the mitral isthmus	ESI Precision	Epicardial (CS) aspect of the epi‐­endo connection
Left	Roof‐­ dependent	Epi‐­endo breakout: Anterior to roof line, near the right superior pulmonary vein	ESI Precision	Epi‐­endo breakout site (anterior to RSPV)

AP19‐­01186

Comparing outcome of using modified Valsalva maneuver and standardized Valsalva maneuver in two different patients presented with supra‐­ventricular tachycardia: Which is more effective?

Nixie Elvaretta Liono, Wendy Wiharja, Jeremiah Suwandi, Audrey Hadisurya, Sabrina Aswan, Bertha Bertha

Universitas Pelita Harapan, Indonesia

Introduction:

The Valsalva maneuver is a safe and internationally recommended first‐­line emergency treatment for supraventricular tachycardia(SVT)1‐­3. However, using Adenosine commonly cause unpleasant feeling to the patient, and cardioversion is rarely successful (5–20%)4‐­5. This case tends to compare effectiveness of standardized and modified Valvasalva maneuver which are executed in two different patients with SVT.

Methods:

Case Illustration Case 1: 45 y.o Female presented with palpitation worsening since 10 hours before admission. Associated symptom was dyspnea. On physical examination: BP (100/70 mm Hg), Pulse (190 BPM, regular), RR (24×/minute), other examinations were unremarkable. Electrocardiography showed SVT (HR 210 BPM), and standardized valsalva maneuver was executed. After 1 minute, HR reduced to 170, and SVT did not convert to sinus rhythm. Intravenous Adenosine was given to the patient CASE 2: 50 years old Female presented with palpitation worsening since 6 hours before admission. Associated symptom was dizziness, and dyspnea. On physical examination: BP (110/70 mm Hg), Pulse (180BPM, regular), RR (22×/minute), other examinations were unremarkable. Electrocardiography showed SVT (HR 175BPM), and modified valsalva maneuver was executed. After 1 minute, HR reduced to 100, and SVT was converted to sinus rhythm. Intravenous Adenosine wasn't given to the patient.

Result:

Modified valsalva maneuver which performed for patient in case 2 has more better outcome than for patient in case 1, since this maneuver produce sinus rhythm. REVERT Trial comparing these 2 maneuver shows; out of 428 patients with SVT, 43% (93/214 Patients) using modified valsalva maneuver, SVT return to Normal Sinus Rhythm (NSR) at 1 minute, and in 17% (37/24) using standard valsalva maneuver produce NSR at 1 minute. Using of adenosine is lesser after performing modified valsalva maneuver (108/214 = 50%) than standardized valsalva maneuver (148/214 = 69%).There is no any statistically significant adverse effect on both maneuvers (4% versus 6%).⁶ This REVERT Trial concludes that modified valsalva maneuver is more effective.

Conclusion:

Modified valsalva maneuver, is more efficient and might increase probability of returning SVT to NSR. In patients with cardiovascularly stable SVT, a modified valsalva maneuver should be the first maneuver attempted to convert SVT, since It is simple, zero cost, well tolerated, and with zero serious adverse events.

AP19‐­01201

Three‐­dimensional mapping and cryo ablation of atrioventricular nodal reentrant tachycardia in a patient with dextrocardia and situs inversus

Masato Fukunaga, Kenichi Hiroshima, Kenji Ando

Kokura Memorial Hospital, Japan

Introduction:

Dextrocardia with situs inverses is a rare condition, the anatomical approach for slow pathway ablation in this setting is challenging with conventional method. Cryomapping mode suggests actual slow pathway safely. Combined use of three‐­dimensional mapping makes the procedure even safer. We present a case of atrioventricular nodal reentrant tachycardia in a patient with dextrocardia treated with three‐­dimensional mapping and cryoablation.

Methods:

A 84‐­year‐­old female was referred for our center to treat a narrow QRS tachycardia. She had no particular medical history but a chest X‐­ray showed dextrocardia with situs inverses. We planned to use a cryoablation catheter (Freezor Max, Medtronic Inc., Minneapolis, MN, USA) and three‐­ dimensional (3D) mapping system (Ensite Precision, St. Jude Medical, Inc., St. Paul, MN, USA) for better understanding and safe procedure.

Result:

Catheters were placed in the morphologic right atrium, right ventricle, the coronary sinus, and the His position, where the catheter positions were typical but mirror image (Figure1A). With a multi electrode catheter located in coronary sinus (Snake, Japan Life line,), anatomical map was created. On electrophysiology study, the mechanism of the tachycardia was determined as slow/fast atrioventricular nodal reentrant tachycardia (AVNRT). A cryoablation catheter with 4 mm tip was employed for slow pathway ablation, which was possible to be displayed on the created 3D map. Cryomapping was applied from the inferior aspect of Koch's triangle region, where jump phenomenon was disappeared with ‐­30°C and cryoablation with −70°C for 4 minutes was applied. After several application of temporary success, we gradually moved the catheter up along the tricuspid annulus. Finally, complete success was achieved at the mid septal area (Figure 1B, red tag). Additional application as Freeze saw freeze was done. The tachycardia became non‐­inducible even under isoproterenol infusion. The total procedural time was 105 minutes and the fluoroscopic time 10 minutes. There was no complication and the patient has had no recurrence of palpitation for 6 months.

Conclusion:

To the best of our knowledge, this is the first report to employ cryomapping to AVNRT in a patient with dextrocardia. This way of procedure is reliable especially for such a rare condition of anatomy because the disappearance of jump phenomenon indicate the tip of the catheter is located on the anterograde slow pathway. This direct evidence gives an operator more confidence in a case of unusual anatomy.

AP19‐­01231

Atrial tachycardia originated from non‐­coronary sinus of valsalva

Thanapol Olarnrachin, Watchara Lohawijarn, Tachapong Ngarmukos

Ramathibodi Hospital, Thailand

Introduction:

In a structurally normal heart, atrial tachycardia frequently found originate from crista terminalis, tricuspid annulus, coronary sinus ostium, pulmonary veins, or mitral annulus. Non‐­coronary sinus of Valsalva, which is adjacent to an interatrial septum, sometimes detected to be an origin of atrial tachycardia.

Methods:

We report a patient underwent non‐­coronary sinus of Valsalva atrial tachycardia ablation as well as a review of related literature.

Result:

A 58‐­year‐­old woman sent to our EP lab with intermittent palpitation for 3 months. Physical examination was unremarkable. Twelve‐­lead ECG showed regular, narrow complex, tachycardia at a rate of 160 bpm. with isoelectric P‐­wave in lead I and aVL, negative wave in the II, III, and aVF, with an R‐­P interval of 220 milliseconds. Echocardiogram revealed a structurally normal heart with good LV systolic function. An electrophysiology study performed using the right ventricular (RV) catheter, coronary sinus (CS) catheter and ablation catheter positioned at the His location. The tachycardia was induced by atrial extra stimuli (S1 500 milliseconds, S2 320 milliseconds). Intracardiac electrogram (EGM) showed a regular narrow complex tachycardia, variable cycle length 312‐­410 milliseconds, A‐­A preceded and predicted V‐­V interval, with concentric atrial activation. Right and left atrial electroanatomic mapping (Rhythmia^™ mapping system; Boston Scientific, Natick, MA, USA) showed the earliest activation at the interatrial septal area with local EGM signal earlier than the onset of the P wave on surface ECG of 23 milliseconds and 30 milliseconds respectively. Multiple RF ablation attempts at this site failed to terminate the tachycardia. At this point, we decided to map the non‐­coronary sinus of Valsalva and found the earliest local EGM signal of 50 milliseconds. earlier than the P wave onset. RF ablation at this site terminated the tachycardia within 5 seconds and rendered it non‐­inducible. Prevalence of atrial tachycardia originating from non‐­coronary sinus of Valsalva in all patients with focal atrial tachycardia was 4.1%‐­8.8% upon the literature, but these numbers might be overestimated in specialized centers, due to referral bias. The decision to evaluate the non‐­ coronary sinus of Valsalva was made after extensive left atrium and right atrium mapping revealed focal atrial tachycardia with earliest atrial activation near the His. Ablation in the non‐­coronary sinus of Valsalva at the site of earliest activation, if the tachycardia terminates within 10 seconds, the procedure is successful. The procedure seems a safe procedure as 1% of complication rate (risk for cerebral embolism) with 99% long‐­term ablation success.

Conclusion:

Dealing with atrial tachycardia with the earliest activation on an interatrial septum, the non‐­coronary sinus of Valsalva should be considered as one of the possibilities of an origin.

AP19‐­01248

Clinical predictor for recurrence in patients undergoing catheter ablation of atrioventricular nodal reentry tachycardia

Su Bin Lim, Jong‐Il Choi, Yun Young Choi, Ha Young Choi, Do Young Kim, Ki Young Boo, Yun Gi Kim, Kwang‐No Lee, Jaemin Shim, Jin Seok Kim, Young‐Hoon Kim

Korea University Medical Centre, South Korea

Introduction:

AH interval jumps or slow–fast atrioventricular nodal echo beats may still be inducible in patients undergoing successful radiofrequency catheter ablation (RFCA) of atrioventricular nodal reentrant tachycardia (AVNRT). Presence of residual single echo beats with an echo zone longer than 30 milliseconds may increase the risk of AVNRT recurrence. These findings are likely to be the result of conduction over a different slow AV nodal pathway than the one required to sustain AVNRT. We aimed to find additional post‐­RFCA electrophysiologic predictors for recurrence of AVNRT.

Methods:

We retrospectively evaluated patients who underwent RFCA for AVNRT.. We compared the post‐­RFCA electrophysiologic parameters between patients with recurrence and those without recurrence.

Result:

A total of 1000 consecutive AVNRT patients were successfully treated with RFCA. There were 15 patients who had AVNRT recurrence (1.5%; mean age, 43.5 ± 4.0 years; 7 (46.7%) were female) and 985 patients without recurrence (98.5%; mean age, 44.3 ± 0.6 years; 603 (61.2%) were female). In the recurred group, one had atypical pathway (fast‐­slow) and 14 had typical pathway (slow‐­ fast).There was no significant difference in the presence of post‐­RFCA AH jump (71% in the recurred group vs 71% in the non‐­recurred group, P = .950) and the slow pathway window (54.8 ± 2.6 vs 32.5 ± 10.3 milliseconds, P = .300) between the recurred and non‐­recurred group. The presence of echo beats (79% vs 79%, P = .99) and the echo window (40 ± 2.2 vs 30 ± 20 milliseconds; P = .61) was also similar. None of the recurred patients had inducibility after redo ablation.

Conclusion:

The overall recurrence rate was low (1.5%) in AVNRT patients undergoing RFCA. The presence of post‐­RFCA AH jumps and echo beats were similar in patients with and without recurrence. The slow pathway and echo window were also similar between the two groups. These findings suggest that post‐­RFCA AH jumps and echo beats are not reliable markers for predicting the recurrence in patients with AVNRT.

AP19‐­01250

Safety and efficacy of radiofrequency catheter ablation of atrioventricular nodal re‐­entrant tachycardia in paediatric patients

Prabhakar Reddy, Muthiah Subramanian, Debabrata Bera, Sachin Yalagudri, Daljeet Saggu, Soumen Devidutta, Calambur Narasimhan

CARE Hospital, India

Introduction:

Although there is abundant data regarding the catheter ablation of the slow pathway (SP) in adult patients with atrioventricular nodal re‐­entrant tachycardia (AVNRT), little is known about the long‐­term outcomes in children. The objectives of this study were to describe the short term success, safety, and long term outcomes of radiofrequency catheter ablation of AVNRT in paediatric patients.

Methods:

Data of all paediatric patients who underwent catheter ablation for supraventricular tachycardias was retrospectively analysed. Details about clinical presentation, diagnosis, ablation procedure, and long term outcomes were extracted from the hospital database. With regards to AVNRT ablation, successful procedural endpoint was defined as SP ablation (no residual dual atrioventricular nodal physiology) or SP modification (residual SP conduction allowing for a maximum of one atrial echo beat).

Result:

Catheter ablation of 163 patients with supraventricular tachycardia was attempted between January 2008 and January 2019. Among these patients, 36 (22.1%) had AVNRT. The mean age was 12.7 + 4.7 years and 20 (55.6%) of the children were girls. Ten patients (27.8%) were less than 10 years. All but one of the patients (post atrial septal defect closure) had structurally normal hearts. Acute success was achieved in all 36 patients (100%). No complications (heart block, vascular access, stroke, pericardial effusion) occurred during the hospital admission. One patient was lost for follow up. During a long term follow up of 81.3 + 51.6 months, there was no recurrence of AVNRT or requirement of medication in any of the patients. In addition, no late complications including atrioventricular block were noted.

Conclusion:

Radiofrequency catheter ablation of AVNRT was effective in 100% of our paediatric patients during long term follow up. No long term adverse complications were noted.

AP19‐­01260

Identical anatomical location of accessory pathway in a first‐­degree relative with atrioventricular reentrant tachycardia

Khairul Mawaris

Universitas Gadjah Mada, Indonesia

Introduction:

Accessory conduction pathway has been thought to result from a cardiac developmental defect in electrical insulation between atria and the ventricles. Wolf‐­Parkinson‐­White (WPW) syndrome can cause paroxysmal supraventricular tachycardia. The prevalence is 0.1%‐­0.3% in the general population and 3.4% in first‐­degree relatives. The location of accessory pathway (AP) could be anywhere along AV rings. During past two decades a significant heritable factor is increasingly recognized as well as familial WPW syndrome has also been described. This report presents a case of first degree relative with history of tachyarrhythmia and identical AP location as identified by electrophysiologic study (EPS).

Methods:

Case 1 A 16‐­year‐­old female student (Patient A) was reffered to our hospital for history of several palpitation episodes. The resting ECG showed pre‐­excitation. There were no history of other disease. Laboratory examination and echocardiography was normal. EPS identified eccentric activation at left side. Mapping via coronary sinus revealed AP at left lateral area of mitral ring. Application of multiple RFA during sinus eliminated pre‐­excitation. There were no inducible tachyarrhythmias nor retrograde conduction after procedure. Case 2 A 51‐­years‐­old female (Patient B, the mother of patient A) was referred to our hospital also for history of palpitation. There was no pre‐­excitation from resting ECG. Echocardiography showed mild LA dilatation with moderate mitral regurgitation. Mapping via coronary sinus identified the AP was at left lateral area of mitral ring. Several application of RF energy at this level during tachycardia eliminated retrograde conduction without any inducible arrhythmias.

Result:

Discussion: Accessory pathways are thought to result from developmental failure to eradicate the remnants of AV connections, other than specialized conduction system, during cardiogenesis. The PRKAG2 gene has been described to be associated with WPW syndrome in autosomal dominant pattern associated with heart disease. However, the genetic basis of isolated sporadic WPW syndrome and AP formation is still unknown. In this case, the daughter had a manifest left lateral Kent pathway and her mother had a unidirectional retrograde AP at the same position. Both patient have no evidence of associated cardiomyopathy. The exact mechanism resulting in the formation of AP is still unclear, it may be determined by mosaic somatic mutation or by environmental exposure.

Conclusion:

This report presents a case of first‐­degree relative presenting with AVRT. Electrophysiology study revealed a similar location of accessory pathway on left lateral mitral annulus. This finding supports a suggestion that a genetic factors may have a role in the pathogenesis of formation of accessory pathway.

AP19‐­01276

Case report: Additional accessory pathway during the ablation procedure in atrioventricular reentry tachycardia (AVRT)

Chyntia Monica Gultom, Miftahurrahmah Galuh Mayang Sari, Agung Fabian Chandranegara

Pasar Rebo General Hospital, Indonesia

Introduction:

Atrioventricular reentry tachycardia (AVRT) is the most common type of supraventricular tachycardia (SVT). Radiofrequency ablation (RFA) is a procedure to treat AVRT with a high success rate. An additional accessory pathway is a common foundings event during the ablation procedure.

Methods:

We presented a case of AVRT with multiple accessory pathway during RFA. A 56‐­year‐­old female patient with a chief complaint of a frequent and long duration of palpitations, shortness of breath and fatigue for the last 6 months. No abnormal physical examinations, laboratory and echocardiography were found. The patient then underwent elective electrophysiology study planned to follow by a conventional ablation. From electrophysiology left lateral accessory pathway was found. An ablation procedure then performed targeting a left lateral accessory pathway during tachycardia. During the ablation we encounter a changed cycle length with different morphology of surface ECG that shows there was an adjacent multiple accessory pathway, then we continue the RFA targeting different site of VA fusion. The ablation procedure was successful, the rhythm converted spontaneously to sinus rhythm during RFA, and VA dissociation was noticed. No tachycardia‐­induced after RFA.

Result:

Radiofrequency ablation is an effective procedure to treat AVRT. In this case, an additional accessory pathway has occurred during the procedure. Reportedly, an anatomically different and annular tissue plays a substantial role in this event. This is a rare event where there is a dual accessory pathway participated.

Conclusion:

An additional accessory pathway is a rare event that can be occurred due to anatomically different and annular tissue during ablation procedure.

AP19‐­01277

A case of orthodromic reciprocating tachycardia by an accessory pathway demonstrated intermittent conduction on the specific coupling intervals

Issei Yoshimoto, Koichi Inoue, Ryo Kitagaki, Masato Okada, Nobuaki Tanaka, Yuko Hirao, Takafumi Oka, Koji Tanaka, Kenji Fujii

Sakurabashi Watanabe Hospital, Japan

Introduction:

We present a case of 42‐­year old man. He was referred to our hospital, undergoing catheter ablation for paroxysmal supraventricular tachycardia which was the cause of syncope.

Methods:

Ventriculoatrial (VA) conduction by retrograde atrioventricular node pathway was obtained with programmed ventricular extra stimulation. On the other hand, VA conduction, on which earliest atrial activation site (EAS) was demonstrated at the portion of coronary sinus (CS) ostium, was intermittently detected. Clinical tachycardia was induced at V‐­A‐­V response by programmed atrial extra stimulation, and the tachycardia cycle length was 280 milliseconds. VA conduction on the tachycardia showed the same atrial activation sequence as intermittent VA conduction with ventricular stimulation, as mentioned above. It was impossible to perform entrainment from the right ventricle as a maneuver for differential diagnosis, because the tachycardia showed termination without atrial capture easily by ventricular overdrive pacing (VOP). Finally, the total pacing prematurity (TPP) obtained by VOP was less than 125 milliseconds with reproducibility, and the tachycardia was diagnosed as an orthodromic reciprocating tachycardia. A discrete high frequency electrogram between the atrial and ventricular components at the left posteroseptal portion was detected by trans‐­septal approach, using programmed ventricular extra stimulation to demonstrate intermittent VA conduction by the accessory pathway (AP). We applied radiofrequency energy to the portion.

Result:

Follow‐­up was uneventful.

Conclusion:

Regardless of intermittent conduction by the AP and instability of the tachycardia in this case, TPP was useful for differential diagnosis.

AP19‐­01293

Elective cardioversion, indications, success and complications. Five year experience in a Tertiary Care Hospital in Pakistan

Intisar Ahmed, Hunaina Shahab, Aamir Hameed

Aga Khan University Karachi, Pakistan, Pakistan

Introduction:

Supraventricular arrhythmias, especially, like atrial flutter and fibrillation are independent risk factors for thromboembolic complication, including stroke. .Furthermore, tachyarrhythmias are associated with tachycardia induced cardiomyopathy and heart failure. Although thromboembolic complications can be prevented by proper anticoagulation, cardioversion decreases the risk of complications, but also improves patients` symptoms and quality of life.

Methods:

A retrospective observational study was conducted involving 53 participants, who were electively admitted for cardioversion in the Coronary Care Unit (CCU) of the Aga Khan University Hospital, Pakistan. Data was collected by reviewing the hospital charts. Any further complication or recurrent arrhythmia immediately after cardioversion and until 1 year after the cardioversion was studied.

Result:

Out of 53 patients, 58.5% (n = 31) were males. The mean age of the participant was 48.17 ± 18.43 years. The presenting rhythm was atrial flutter in 77.7% of the patients (n = 38) while the remaining had atrial fibrillation. The mean hospital stay was 1.17 ± 0.42 days. The most common indication for cardioversion was palpitations in 44% (n = 23) of the subjects. About 38% (n = 20) had uncontrolled ventricular rate. Seventeen percent (n = 9) were cardioverted due to tachycardia induced cardiomyopathy and about 2% (n = 1) were cardioverted due to the inability to tolerate antiarrhythmic medications. Seventeen patients (32.1%) had underlying valvular heart disease Eight patients (15.1%) had previous known cardiomyopathy. About 13% (n = 7) had congenital heart disease and 39.6% (n = 21) had no any underlying cardiac disease. Trans‐­esophageal echocardiogram was done in 47.2% (25) of patients before cardioversion to rule out a left atrial/ left atrial appendage thrombus. About 74% (n = 39) were cardioverted without anesthesia cover and only 3.8% (2) patients required mechanical ventilation. Our data showed that 94.3% (n = 50) were cardioverted successfully into sinus rhythm and mean energy required for cardioversion was 115.2 ± 63.2 joules. About 93% patients followed up until 6 months follow up after cardioversion while 85% followed up until 1 year after cardioversion. Of all the patients who were successfully cardioverted, 84.9% (n = 45) were remained in sinus rhythm at six weeks, 52.8% (n = 28) at six months and 39.65 (n = 21) remained in sinus rhythm at one year follow up. All patients were anticoagulated for more than four weeks after cardioversion. None of the patients required pacemaker after cardioversion and no one developed stroke after cardioversion.

Conclusion:

With a proper patient selection, electrical cardioversion is a low risk procedure. It has very high success rate and relatively low complications in our population with atrial fibrillation and atrial flutter.