Pediatrics and GUCHs

AP19‐­00017

Efficacy and outcome of radiofrequency catheter ablation among arrhythmia with congenital heart disease: Ramahibodi experience

Titaya Sukhupanyarak, Kanchit Likittanasombat, Pakorn Chandanamattha, Tachapong Ngarmukos, Sirin Apiyasawat, Tarinee Tangcharoen

Ramathibodi, Thailand

Introduction:

In Thailand, the radiofrequency catheter ablation among arrhythmia with congenital heart disease was limited.

Methods:

The retrospective study with symptomatic arrhythmic congenital heart disease for catheter ablation procedure during 1 January 1996 until 31 December, 2017. Clinical data, ablation procedure were classified.

Result:

The congenital heart disease among arrhythmia in Ramathibodi hospital 29 patients There were male 11 (37.9%) patients, mean age 36.3 years old, ASD 10 (34.5%) patients and Ebstein's anormaly 9 (31.0%) patients, respectively. The efficacy of treatment was 95.1%. The most common arrhythmias were AVRT 12 (41.4%) patients and atrial fibrillation 6 (20.7%) respectively. The complication was AV block 2 (6.9%) patients.

Conclusion:

Catheter ablation was effective treatment and low complication for arrhythmia congenital heart disease.

AP19‐­00078

High‐­density mapping of atrial tachyarrhythmia in congenital heart diseases—Single tertiary centre experience in Hong Kong

Sit‐Yee Kwok, Tak‐Cheung Yung, Ngai‐Lun Ho, Jo‐Jo Hai, Sabrina Tsao, Hung‐Fat Tse

Queen Mary Hospital, Hong Kong

Introduction:

High‐­density electroanatomical mapping is increasingly employed in complex arrhythmia ablation. However, the use of this technology in Chinese population for congenital heart disease (CHD) is not well reported.

Methods:

Retrospective review of consecutive transcatheter ablation of atrial tachyarrhythmia using high‐­density mapping for CHD patients (at least moderate complexity) in the only tertiary congenital heart centre in the territory from January 2017 to January 2019 was conducted. Orion mapping catheter in Rhythmia system (Boston Scientific) was used to create activation and voltage maps. Parameters including mechanism of arrhythmia, acute success, and follow‐­up data were recorded.

Result:

Eight patients were identified (median age 35.5 years, IQR 31.2‐­42.1 years) who underwent transcatheter ablation of atrial arrhythmia (focal atrial tachycardia‐­1; intra‐­atrial reentry tachycardia (IART)‐­3; both‐­4). More than one reentry circuits of IART were identified in five patients, in which three patients had three or more IART mechanism. A median of two maps were acquired per person and it took in median 32.4 minutes (IQR 15.6‐­50.6) with median number of 15 952 (IQR 13 395‐­18 530) mapping points per map. Cavo‐­annulus isthmus dependent mechanism was the predominant reentry mechanism. At least one of the arrhythmia was ablated in all the patients. In two patients (25%), there was residual atrial arrhythmia which was not ablated. There was recurrence of atrial arrhythmia in three patients (37.5%). Additional targeted substrate ablation was performed in six patients with multiple IART circuits. Near‐­miss anatomical pouches were identified in three patients.

Conclusion:

High acute success rate of atrial arrhythmia ablation can be achieved using high‐­density anatomical mapping in CHD. Substrate ablation was required with multiple IART circuits identified.

FIGURE A 41‐­year‐­old male with congenital corrected transposition of great arteries. (case 2) A and B: Electrophysiological study identified multiple atrial tachycardia with different cycle lengths. C: No single mechanism of atrial tachycardia could be identified. Voltage mapping identified low voltage area (red: <0.125 mV; purple >0.5 mV). RF ablation line (black dots) was created to connect low voltage region. D and E: Focal atrial tachycardia. Earliest atrial activation was identified over the crista terminalis, with local atrial activation 43 ms ahead of the onset of P wave. RF ablation at this region successfully terminated the tachycardia. F: High‐­density mapping of another AT suggested clockwise cavoannular dependent intra‐­atrial reentry tachycardia. G: RF ablation line was created (pink dots) and IART was terminated.

TABLE Patient characteristics and transcatheter ablation summary

Case	Age/Sex	Diagnosis	Tachycardia Mechanism	Ablation site	Acute success?	EGM	AT recur?
1	36.6/M	Atriopulmonary Fontan (DIRV, hypoplastic LV,VA discordance,VSD)	Focal AT	AT focus in right atrial pouch	Yes	18 192	Yes
2*#	41.5/M	ccTGA, severe PS, ASD	1. Focal AT 2. IART 3. IART 4. JT/ AVNRT	1. Crista terminalis 2. Right posterolateral 3. “CTI” 4. NOT ablated	Partial	17 785 15 745 17 688	Yes
3	56.4/M	Repaired TOF	1. IART 2. Focal AT (nonsustained)	1. CTI ablation 2. NOT ablated	Yes (confirmed CTI block)	10 882 18 825	Yes
4*#	29.4/F	Atriopulmonary Fontan (DILV, hypoplastic RV)	1. IART 2. Focal AT	1. Lateral RA line 2. Septal RA	Partial	14 379 10 764	No
5#	34.4/M	Atriopulmonary Fontan (Situs inversus, AV discordance, Dominant RV, Rudimentary LV, DORV, PS)	1. IART 2. IART	1. Posterolateral RA line creation 2. cavo‐­annular isthmus ablation	Yes (confirmed isthmus block)	31 306 29 691	No
6#	31.1/M	PAIVS s/p pulmonary valvotomy and PVR	1. IART 2. IART	1. CTI ablation 2. posterolateral RA	Yes (confirmed CTI block)	10 594 14 251	No
7#	43.7/M	Hypoplastic bipartile RV, ASD s/p ASD closure	1. IART 2. IART/AT 3. Focal AT 4. Focal AT	1. CTI ablation 2. posterolateral RA line creation	Yes (confirmed CTI block)	50 928 16 158	No
8#	31.3/M	Dextrocardia, DORV, subaortic VSD, PS s/p repair; Myocardial infarction s/p CRTD implantation	1. IART 2. IART	1. CTI ablation 2. lateral RA (atriotomy) line creation	Yes (confirmed CTI block)	10 677 14 233	No

ccTGA, Congenitally corrected transposition of great arteries; RV, right ventricle; LV, left ventricle; VSD, ventricular septal defect; AV discordance: atrioventricular discordance; VA discordance: ventricular‐­arterial discordance; PS, pulmonary stenosis; ASD, atrial septal defect; TOF, Tetralogy of Fallot; PVR, pulmonary valve replacement; CRTD, Cardiac Resynchronization Therapy Defibrillator; AT, atrial tachycardia; IART, intra‐­atrial reentrant tachycardia; JT: junctional tachycardia; AVNRT: atrio‐­ ventricular nodal reentry tachycardia

*Redo

#Substrate mapping/ablation

AP19‐­00142

Mid‐­term outcome of retrograde transaortic method for left accessory pathway and left ventricular catheter ablation utilizing zero or near‐­zero fluoroscopy guidance in pediatric population—A single center study

Wei‐Chieh Tseng, Mei‐Hwan Wu, Chun‐Wei Lu, Kun‐Lang Wu, Shuenn‐Nan Chiu

National Taiwan University Children's Hospital, Taiwan

Introduction:

Retrograde transaortic method is widely used in pediatric population during ablation for left arrhythmia substrate using fluoroscopic guidance. Zero or near‐­zero fluoroscopy (ZF) technique has been advocated but the safety and feasibility for left side lesion are not well delineated.

Methods:

All patients who received ablation of left side arrhythmia substrate in our hospital between Jan 2014 and May 2018 were enrolled. The study group consisted of 21 procedures in 20 patients (male/female 14/6) using ZF guidance and control group consisted of 33 procedure in 30 patients (male/female 18/12) using fluoroscopy guidance. Echocardiographic studies were performed before and after the ablation procedure.

Result:

The mean procedure time was 68.24 ± 32 minutes in control group and 83.48 ± 42.78 minutes in study group (P = .141). The mean fluoroscopy time (FT) was significantly lower in study group (1.33 ± 3.53 vs 27.03 ± 18.86 minutes, P < .001). Acute procedural success rate was 100% in both groups, and the recurrence rate was 12.1% in control group and 4.7% in study group (P = .363) after median of 17 and 13.9 months follow‐­up. Six procedures (one in study group and five in control group) involved multiple arrhythmia substrates. For single left side accessory pathway (20 in control and 18 in study group), the procedure time was longer in study group (58.6 ± 28.68 minutes vs 85.56 ± 45.6, P = .034). For left ventricular ventricular tachycardia ablation (three in study and eight in control group), the procedure time showed no significant difference. Echocardiography after ablation revealed no progression of aortic regurgitation in all patients.

Conclusion:

Utilizing ZF guidance for left arrhythmia substrate ablation through retrograde transaortic method is safe and feasible without increase incidence of aortic valve damage in mid‐­term follow‐­up.

AP19‐­00183

Type and management of tachycardia in admitted neonates and infants: Ten‐­year experience in Daegu city

Myung Chul Hyun

Kyungpook National University Hospital, South Korea

Introduction:

Sustained tachycardias are important clinical problems in neonates and infants. Their myocardium is intrinsically more vulnerable to high ventricular rate, and arrhythmias can be life‐­ threatening early in life. The aim of this study was to evaluate the characteristics, management and prognosis of subjects with tachycardia on the basis of our ten‐­year experience.

Methods:

A total of 62 neonate and infants whose ECG showed tachycardia within the first year of life between June 2007 and June 2017 at three medical centers in Daegu were enrolled. Patients who had sinus tachycardias were excluded.

Result:

Thirty‐­five boys and 27 girls were admitted for management of tachycardia. Their tachycardias were diagnosed at an average age of 2 month (1 day‐­10 month) and an average weight of 4.6 kg (2.2‐­11 kg). Half of the patients had tachycardia attack in the first month of life (31/62), and most (51/62) had it within the first three months. Only 7 patients presented with tachycardia after 6 months of age. Twenty‐­one patients (34%) were associated with OHS (group 1) (Table 1). In 41 patients who did not undergo OHS (group 2), SVT was the most common (20/41), the second was atrial tachycardia (AF and MAT, 15/41) and the remaining was VT (6/41). Almost half of them (18/41, 44%) was noticed incidentally, and 22% (9/41) and 30% (12/41) were noticed as fetal arrhythmia and subtle findings, respectively. Nine patients showed congestive heart failure and all of them were under 3 months of age. In patients who underwent OHS, JET was the most common (16/21) and sometimes resulted in hypotension. Their tachycardias were detected during cardiac monitoring for postoperative care. The first line therapy was cardioversion for AF, adenosine for SVT, amiodarone or conservative treatment for JET, and verapamil or cardioversion for VT (Figure 1). For the 29 patients, maintenance therapy began with antiarrythmics including beta blocker, digoxin, class I or III drugs (Figure 2). The duration of medication was median 26 months (2‐­75 month). Tachycardia did not recur in most of them after the first three months. Three patients failed completely tachycardia control. One patient with AVRT underwent ablation at 6 years old. The other patients (one AVRT, one MAT) were treated with beta blocker and amiodarone, but the patient with MAT did not show normal sinus rhythm on ECG and had sudden cardiac death. None of the others died.

FIGURE 1 Management for acute termination of tachycardia

FIGURE 2 Management for prevention of recurrence of tachycardia

Conclusion:

In the neonate and infants, AVRT and post‐­OHS JET are the most common type of tachycardia. Other types of tachycardia, such as AF, MAT, and VT, require precise diagnosis before treatment. For the specific myocardial state of subjects, accurate diagnosis and appropriated treatment can decrease the morbidity of tachycardia.

TABLE 1 Tachyarrhythmia corresponding to operation of CHD

CHD	Operation (No)	Type of tachyarrhythmia (No)
VSD	RA‐­tomy, pericardial patch closure (7)	JET(9)
	PA‐­tomy, pericardial patch closure (2)
ASD	RA‐­tomy, pericardial patch closure (1)	AVRT(1)
TGA	ASO with RA‐­tomy, VSD pericardial patch closure (3)	JET(4), AF(1)
	ASO with RA‐­tomy, ASD pericardial patch closure (2)
TOF	Total correction with RVOT patch(2)	JET(1), AVRT(1)
DORV	Intraventricular tunnel repair & PA tomy, VSD	JET(1), VT(1)
	pericardial patch closure (1)
	Intraventricular tunnel repair & ASO & RA‐­tomy, ASD
	pericardial patch closure (1)
CoA	Arch reconstruction & RA‐­tomy, ASD pericardial patch closure (1)	MAT(1)
TA	Bidirectional cavo‐­pulmonary shunt (1)	JET(1)

AP19‐­00380

Mapping of atrial premature complexes triggering onset of atrial fibrillation in patients with atrial septal defect

Koji Nakagawa, Atsuyuki Watanabe, Yoshimasa Morimoto, Tomonari Kimura, Saori Asada, Masakazu Miyamoto, Nobuhiro Nishii, Kazufumi Nakamura, Hiroshi Morita, Hiroshi Ito

Okayama University Hospital, Japan

Introduction:

Atrial fibrillation (AF) is one of the most common comorbidities in middle‐­aged and elderly patients with atrial septal defect (ASD). It has been shown that pulmonary vein (PV) ectopy can trigger AF and electrical isolation of PVs can suppress AF in many cases. And to this day, PV isolation (PVI) is the cornerstone of catheter ablation strategy for AF in patients without specific structural abnormalities. However, it is still not validated whether the PV is also the major origin of ectopic activity triggering AF and PVI is a reasonable treatment strategy in ASD patients with AF. We aimed to evaluate the origin of ectopic activities triggering the onset of AF in patients with ASD.

Methods:

The subjects of this study were 14 unclosed ASD patients (7 women and 6 men, median age 67 years) who underwent catheter ablation of paroxysmal or persistent AF in our hospital. Spontaneous or isoproterenol‐­induced atrial premature complexes (APCs) were mapped before catheter ablation of AF. Foci of APCs triggering the onset of AF were mapped using 4 multielectrode catheters located in the coronary sinus (covered coronary sinus and RA/SVC), right superior PV, left superior and inferior PVs, respectively. Isoproterenol (ISP) was infused through a peripheral vein at rates of 5, 10, 15, 20 μg/min for 2 minutes at each infusion rate until AF was induced. The foci of APCs were localized according to the earliest atrial activity relative to the reference electrogram or the onset of the APC's P wave. PVI was performed after the ISP infusion study in all patients.

Result:

AF was induced by ISP infusion in 9 (60%) of 15 ASD patients, and 19 PACs triggering the onset of AF were observed in those patients. Among them, the focus of 6 (32%) APCs was in the right superior PV, 12 (63%) in the left superior PV and 1 (5%) in the left inferior PV. After the ISP infusion study, PVI was performed successfully in all patients. Seven (78%) of nine patients with PV foci APCs maintained sinus rhythm during a median follow‐­up period of 18 months after the PVI.

Conclusion:

Our results suggest that the PVs are the important origin of APC triggering onset of AF and PVI is a reasonable treatment of AF in patients with ASD. Further larger studies are needed to confirm these findings.

AP19‐­00440

Pacemaker longevity; a small cost for safety on the young with pacemaker dependence

Suleman Kamberi, Andrew Davis

Royal Children's Hospital, Australia

Introduction:

Children with pacemaker dependence (PD) remain a concerning group of patients because of the risk of sudden death should pacemaker failure occur. Our management policy has been to keep ventricular outputs 5.0 V at 0.5 milliseconds and 3 monthly check ups. Some patients are managed with two ventricular leads using CRT devices.

Methods:

Retrospective database review was undertaken on patients attending a single institution between January 1997 and April 2019. We reviewed out pacemaker data base to look at the effects of longevity on this policy. Pacemaker dependence was defined as the absence of underlying escape rhythm >30/minute at least one pacemaker check.

Result:

Over the study period a total of 120 children with epicardial pacemakers were followed. All but one patient had ventricular capture management turned off. Early in the series, one patient with permanent PD aged 12 years, paced for iatrogenic post‐­operative AV block after surgery died suddenly, presumably from loss of capture. This patient had ventricular capture management turned on. Since then we have not used capture management. Total of 71 patients had battery replacement. Of these 16 (22%) were PD of which 11 (15%) had battery replacement and 104 patients (78%) were pacemaker non dependent (PND) of which 60 patients (85%) had battery replacement. In the pacemaker dependent group 2 patients (18%) had 3 battery replacement, five patients (46%) had 2 battery replacement and four patients (36%) had 1 battery replacement. Mode of pacing was DDD in all 11 patients in pacemaker dependent (PD) group out of which six patient upgraded to BiV pacing for safety reason. In the pacemaker non dependent (PND) group 2 patients (3%) had 3 battery replacement, 12 patients (20%) had 2 battery replacement and 46 patients (77%) had 1 battery replacement. Mode of pacing was DDD/R in 35 patients, VVI/R in 10 patients, AAI/R –DDD/R in three patients, VDD in one patient and ADIR in one patient. Upgraded to BiV in three patients. Pacemaker longevity in the pacemaker dependent group was 24‐­108 months with median 60 months. In the pacemaker non dependent (PND) group pacemaker longevity was 14‐­108 months with median 84 months.

Conclusion:

Our policy has been effective and resulted in a decrease in longevity of median 60 months in pacemaker dependent (PD) group compared to median 84 months in the pacemaker non dependent (PND) group.

AP19‐­00473

Pediatric arrhythmias

SEM Malen, MAM Chandara

Calmette Hospital, Cambodia

Introduction:

Arrhythmias may occur at any age. Although, children with arrhythmias experience no specific symptoms. Some abnormal clinical finding will orient to diagnosis measure. The most common arrhythmias occur in pediatric cardiac intensive care unit. Beside arrhythmias associated with congenital heart disease, surgery repair, electrolytes and acid‐­bas imbalance; arrhythmias can also occur in children without structural heart disease.

Methods:

There are 13 cases of cardiac arrhythmias registered in three hospitals in Cambodia including: Five cases of tachyarrhythmias were ablated by radiofrequency, seven cases of AV bloc were implanted the pacemaker, one case of AV bloc and long QT syndrome was implanted ICD.

Result:

All the cases of device implantation were implantation successfully in collaboration with cardiac surgeons.

Conclusion:

Pediatric cardiac arrhythmias were found infrequently. The tachyarrhythmias were ablated and cured and the bradyarrhythmias were implanted the devices.

AP19‐­00638

Nonselective His‐­bundle pacing in a 3‐­year‐­old boy with postoperative complete atrioventricular block

Chieh‐Mao Chuang, Kuo‐Hung Lin, Jeng‐Sheng Chang, Yun‐Ching Fu, Tsung‐Cheng Shyu

China Medical University Children's Hospital, Taiwan

Introduction:

His‐­bundle pacing has been proved to be an effective strategy for pacing related ventricular dyssynchrony. However, small size of His‐­bundle and right atrium in young children could prohibit the procedure or make it challenging. Our study aim is to report a successful nonselective His‐­ bundle pacing (NS‐­HBP) in a 3‐­year‐­old boy with postoperative complete atrioventricular block (CAVB).

Methods:

Nil.

Result:

A 3‐­year‐­old boy with a history of d‐­transposition of the great arteries and ventricular septal defect receiving surgical repair and postoperative CAVB under epicardial single chamber pacemaker (Figure A) presented with vomiting. CAVB without ventricular pacing was documented owing to epicardial lead fracture. Emergent temporary right ventricular pacing catheter was inserted. Echocardiography showed left ventricular dilatation with dyssynchrony. Considering pacing related cardiomyopathy, cardiac resynchronization therapy via HBP was planned. C315HIS sheath was inserted to right atrium via left axillary vein. No His‐­bundle signal was recorded by 3830 lead or quadripolar catheter. Para‐­Hisian region was identified by pacemapping. Lead was actively fixed and threshold of HB capture was 2.5 V at 1 millisecond. NS‐­HBP was achieved (Figure C). Redundant right atrial loop was created and generator (VVIR, Metronic Ensura) was connected (Figure B). No more ventricular dyssynchrony was noted by echocardiography with good weight gain after HBP.

Conclusion:

The NS‐­HBP is feasible and safe for postoperative CAVB with ventricular dyssynchrony in young children with congenital heart disease.

AP19‐­00647

Low dose carvedilol therapy in catecholaminergic polymorphic ventricular tachycardia (CPVT): A case report

Yoshitaka Ito, Yasushi Suzuki, Subaru Tanabe, Kazuhiro Naito, Hiroki Kojima, Isao Kato, Toru Iwa, Tetsuya Amano

Aichi Medical University, Japan

Introduction:

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a relatively rare inherited disease presenting with arrhythmic events during physical exercise or emotional stress. CPVT is caused by mutations in genes encoding ryanodine receptor type2 (RyR2) and cardiac calsequestrin (CASQ2). About 80% of affected individuals experience recurrent syncope, and 30% experience cardiac arrest. Bisoprolol (β‐­bloker) is the first‐­choice treatment of CPVT therapy, but attention should be paid to side effects of bradycardia, hypotension and heart failure. In recent years, it has been reported that Flecainide is effective for CPVT, but it is reported that it is necessary to administer a high capacity. Carvedilol acts directly on RyR2 and its effect to suppress Ca2+ release has been reported, and there is a possibility that it is effective for CPVT, but there are few reports that it is effective for CPVT.

Methods:

A 7 year‐­old man presented with syncope once every 2 months when he was intensely Karate training, running, or excited about computer game with his friends. There was nothing in the past history and family history. ECG findings at rest and UCG findings were normal. We strongly suspected CPVT as the underlying disease, because the patient's medical history included recurrent syncope during physical and emotional stress. Holter ECG during Karate performance showed polymorphic VT. As a result of genetic screening, missense mutation of the previous announcement was detected in RyR2, and we diagnosed him as CPVT. We started of oral treatment of carvedilol 0.21 mg/kg/d, concerned about his very young age and side effects of bisoprolol (bradycardia and decreased tolerability of exercise) after careful and sufficient informed consent.

Result:

Ten months have passed after starting medication, no syncope is appreciated despite the fact that he was continuing intense training in baseball. No VT was recorded by treadmill exercise test without increasing dose of carvedilol.

Conclusion:

We present a case that low dose carvedilol for CPVT patient was effective.

AP19‐­00653

Ventricular fibrillation in a girl with heterozygous SCN5A V1777M mutation presented bradycardia dependent prolonged QT interval and exercise‐­provoked two‐­to‐­one atrioventricular block: Case report

Yoko Yoshida, Tsugutoshi Suzuki, Yoshihide Nakamura

Oska City General Hospital, Japan

Introduction:

Two‐­to‐­one atrioventricular blocks (2:1 AVB) are usually observed in severe phenotypes of congenital long QT syndromes in neonatal periods.

Methods:

An 11‐­year‐­old girl suffered from ventricular fibrillation during swimming. Resting ECG was almost normal. Treadmill test provoked 2:1 AVB without prolongations of QT interval. Holter monitoring showed marked prolongation of QT interval while asleep (HR 49 bpm, QT 584 milliseconds, QTcB 524 milliseconds) and no evidence of any grade of AVB. Heterozygote of SCN5A V1777M missense mutation was identified. After administration of propranolol and mexiletine, exercise‐­provoked AVB disappeared accompanied by suppression of maximum atrial rate.

Result:

Lupoglazoff et al. reported a young boy with homozygous SCN5A V1777M mutation who presented 2:1 AVB associated with severe prolongation of QT interval. They also showed patient's electrophysiological studies confirmed the location of the block was in the His‐­Purkinje system rather than at the ventricular level.

Conclusion:

We speculated that 2:1 AVB in our patient related to a potential disturbance in the cardiac conduction system.

AP19‐­00713

Outcomes in Brugada syndrome patients with implantable cardioverter‐­defibrillators: insights from the SGLT2 registry

Sharen Lee, Christien Ka Hou Li, Jiandong Zhou, Tong Liu, Konstantinos Letsas, Ian Chi Kei Wong, Qianpeng Zhang, Gary Tse

The Chinese University of Hong Kong, Hong Kong

Introduction:

Brugada syndrome (BrS) is a cardiac ion channelopathy with characteristic electrocardiographic patterns, predisposing affected individuals to higher risks of sudden cardiac death (SCD). Implantable cardioverter‐­defibrillator (ICD) is used for primary or secondary prevention in BrS, but its use remains controversial amongst low‐­risk asymptomatic patients. The present study aims to examine indicators for ICD implantation amongst BrS patients with different disease manifestation.

Methods:

This study included a registry of BrS patients who received ICD between 1997 and 2019. The cohort was divided into three categories based on presentations before ICD implantation: asymptomatic, syncope, ventricular tachycardia/ventricular fibrillation (VT/VF). The median follow‐­up duration was 95 [0‐­265] months. Univariate and multivariate Cox‐­regression analyses were performed to identify independent predictors of appropriate and inappropriate shock delivery.

Result:

A total of 153 consecutive patients were included. Appropriate shocks were delivered in 37 patients (24.2%) whereas inappropriate shocks were delivered in 30 patients (19.6%). Complications occurred in 39 patients (25.5%). No independent predictors of appropriate or inappropriate shock delivery were found in multivariate Cox regression analysis.

Conclusion:

ICD therapy is effective for primary and secondary prevention of SCD in BrS. Whilst appropriate shocks occur more frequently in BrS patients presenting with VT/VF, they also occur in asymptomatic patients. Further research in risk stratification can help to improve patient prognosis whilst avoid unnecessary ICD implantation.

TABLE 1 Baseline characteristics

Feature	Overall (n = 153)	Asymptomatic (n = 28)	Syncope (n = 111)	VT/VF (n = 41)	P‐­value
Male	148 (96.7)	28 (100)	107 (96.4)	39 (97.6)	.828
Age at Initial BrP Presentation	49.5±15.4	48.4±14.4	50.9±14.0	47.5±18.7	.430
Type 1 BrP	88 (57.5)	15 (53.6)	65 (58.6)	26 (63.4)	.657
BrP Evolution	44 (28.8)	9 (32.1)	32 (28.8)	11 (26.8)	1.000
Fever‐­induced Type 1 BrP	7 (4.58)	0 (0)	5 (4.50)	3 (7.32)	.380
BrS	126 (82.4)	24 (85.7)	91 (82.0)	34 (82.9)	.880
Family History of BrS	4 (2.61)	2 (7.14)	2 (1.80)	0 (0)	.151
Family History SCD	16 (10.5)	7 (21.4)	9 (8.11)	0 (0)	.006
Other Arrhythmia Present	44 (28.8)	11 (39.3)	28 (25.2)	11 (26.8)	.324
EPS Performed	74 (48.4)	19 (67.9)	49 (44.1)	13 (72.2)	.001
Inducible EPS*	63 (85.1)	17 (89.5)	41 (83.7)	7 (77.8)	.644
24‐­Hours Holter	33 (21.6)	6 (21.4)	24 (21.6)	3 (60.0)	.503
Abnormal Holter*	18 (54.5)	3 (50.0)	11 (45.8)	34 (82.9)	.521
Mortality	9 (5.88)	1 (3.57)	6 (5.41)	0 (0)	.601
Follow Up Period (months)	94.5±62.6	117±60.9	92.2±61.5	84.5±65.1	.046

The brackets contain the percentage of patients fulfilling the criteria in the overall cohort, or within the respective subgroup. The P‐­value for categorical variables were obtained by Fisher's exact test, and for continuous variables by Kruskal‐­Wallis rank test one‐­way ANOVA.

^a*indicates that value indicates the patient percentage within the subgroup population where the investigation is performed.

BrS: Later diagnosed with Brugada syndrome

TABLE 1B Baseline characteristics with significant intergroup differences

Characteristic	Overall (n=153)	Asymptomatic (n=28)	Syncope (n=111)	VT/VF (n=41)	P
					A v. S	A v. V	S v. V
Family history of SCD	16 (10.5)	7 (21.4)	9 (8.11)	0 (0)	0.035	0.003	0.161
EPS performed	74 (48.4)	19 (67.9)	49 (44.1)	9 (21.4)	0.035	0.000	0.027
Follow up period (months)	94.5±62.6	117±60.9	92.2±61.5	84.5±65.1	0.081	0.028	0.435

A, asymptomatic; S, syncope; V, VT/VF.

TABLE 2A Outcomes of ICD therapy

Outcome	Overall (n = 153)	Asymptomatic (n = 28)	Syncope (n = 111)	VT/VF (n = 41)	P
Appropriate Shock	37 (24.2)	3 (10.7)	28 (25.2)	17 (42.5)	.011
Inappropriate Shock	30 (19.6)	6 (21.4)	20 (18.0)	10 (25.0)	.575
Lead Malfunction	6 (3.92)	1 (3.57)	5 (4.50)	2 (5.00)	1.00
Lead Dislocation	7 (4.58)	0 (0)	7 (6.31)	3 (7.50)	.463
Infection	5 (3.27)	1 (3.57)	4 (3.60)	0 (0)	.543
Pre‐­ICD VT/VF Episodes	0.440±0.894	‐­	0.407±0.886	1.58±1.01	.000
Post‐­ICD VT/VF Episodes	3.93±11.7	2.39±5.43	3.94±12.5	7.00±15.1	.047
Total VT/VF Episodes	4.60±12.2	2.39±5.43	4.68±0.499	8.58±14.9	.000

TABLE 2B ICD outcomes with significant intergroup differences

Characteristic	Overall (n=153)	Asymptomatic (n=28)	Syncope (n=111)	VT/VF (n=41)	P‐­value
					A v. S	A v. V	S v. V
Appropriate Shock	37 (24.2)	3 (10.7)	28 (25.2)	17 (42.5)	.129	.006	.046
Pre‐­ICD VT/VF	0.440±0.8	‐­	0.407±0.886	1.58±1.01	.027	—	.000
Episodes	94
Post‐­ICD VT/VF	3.93±11.7	2.39±5.43	3.94±12.5	7.00±15.1	.826	.121	.020
Episodes
Total VT/VF	4.60±12.2	2.39±5.43	4.68±0.499	8.58±14.9	.511	.000	.000
Episodes

TABLE 3A Univariate Cox‐­regression analysis of appropriate shock predictors

Clinical Characteristic	Z Score	Hazard Ratio [95% Confidence Interval]	P‐­value
Overall Cohort
Male	−0.65	0.511 [0.066, 3.93]	.519
Age of Initial BrP Presentation	−0.21	0.998 [0.976, 1.02]	.836
BrP Evolution	0.12	1.05 [0.519, 2.10]	.902
Type 1 BrP	1.15	1.48 [0.758, 2.90]	.250
Fever‐­induced BrP	1.21	2.46 [0.576, 10.5]	.225
Syncope	0.85	1.39 [0.649, 2.97]	.398
Other Arrhythmia	1.71	1.80 [0.918, 3.52]	.087
BrS	0.90	1.45 [0.646, 3.27]	.367
Inducible EPS	0.75	2.20 [0.279, 17.3]	.455
Asymptomatic
Male	—	1.00	—
Age of Initial BrP Presentation	0.83	1.04 [0.951, 1.13]	.407
BrP Evolution	0.62	2.41 [0.151, 38.6]	.533
Type 1 BrP	−0.90	0.327 [0.029, 3.74]	.368
Fever‐­induced BrP	—	1	—
Syncope	—	1	—
Other Arrhythmia	0.08	1.11 [0.094, 13.1]	.935
BrS	0.00	0.00 [0, 0]	1.00
Inducible EPS	—	—	1.00
Syncope
Male	0.00	0.00	1.00
Age of Initial BrP Presentation	−0.30	0.996 [0.70, 1.02]	.765
BrP Evolution	−0.19	0.925 [0.412, 2.07]	.849
Type 1 BrP	1.74	2.02 [0.913, 4.48]	.083
Fever‐­induced BrP	0.23	1.26 [0.165, 9.68]	.821
Syncope	0.00	0.00	1.00
Other Arrhythmia	2.10	2.28 [1.06, 4.90]	.036
BrS	−0.09	0.960 [0.383, 2.40]	.930
Inducible EPS	0.44	1.61 [0.196, 13.2]	.659
VT/VF
Male	2.48	33.7 [2.10, 540]	.013
Age of Initial BrP Presentation	−0.01	1.00 [0.969, 1.03]	.990
BrP Evolution	6.44	1.89 [0.645, 5.52]	.246
Type 1 BrP	2.39	6.44 [1.39, 29.7]	.017
Fever‐­induced BrP	1.04	2.25 [0.486, 10.4]	.300
Syncope	0.03	1.02 [0.342, 3.02]	.975
Other Arrhythmia	−0.40	0.882 [0.476, 1.63]	.689
BrS	−0.31	0.968 [0.788, 1.190]	.758
Inducible EPS	‐­	‐­	1.000

TABLE 3B Multivariate Cox‐­regression analysis appropriate shock predictors

Feature	Z Score	Hazard Ratio [95% Confidence Interval]	P‐­Value
Male	−0.81	0.393 [0.041, 3.77]	.419
Type 1 BrP	−0.70	0.893 [0.651, 1.23]	.486
Other Arrhythmia	0.86	1.29 [0.720, 2.31]	.392

TABLE 4 Univariate Cox‐­regression analysis inappropriate shock predictors

Feature	Z Score	Hazard Ratio [95% Confidence Interval]	P‐­Value
Male	−0.81	0.393 [0.041, 3.77]	.419
Type 1 BrP	−0.70	0.893 [0.651, 1.23]	.486
Other Arrhythmia	0.86	1.29 [0.720, 2.31]	.392

FIGURE 1 Kaplan‐­Meier Survival Estimate for Appropriate Shocks

AP19‐­00734

Experience of electrophysiological study and radiofrequency ablation of paediatric patients in adult cardiac centre

Nwe New, Thet Lel Swe Aye

Yangon General Hospital, Myanmar, Burma

Introduction:

In Myanmar, electrophysiological study and radiofrequency ablation service is developing in adult cardiac centres, but availability of service is still lacking for paediatric patients. As a tertiary referral centre in Myanmar, Department of Cardiology at Yangon General Hospital is receiving paediatric patients with history and documentation of tachycardia.

Methods:

Patients under the age of 18 years with tachyarrhythmia who underwent electrophysiological study and radiofrequency ablation at adult cardiac centre from 2007 to June 2019 were retrospectively studied through the case records.

Result:

A total of 145 patients (male 77, female 68) with 11% of patients under the age of 12 years underwent electrophysiological study at Department of Cardiology, Yangon General Hospital which is an adult cardiac centre. Among them, 53% were male patients. 11 patients (7.5%) had normal study and the rest of the patients underwent radiofrequency ablation. Among the various tachyarrhythmias, left sided accessory pathway was the commonest (33%) followed by right sided accessory pathway (27%). Atrioventricular nodal tachycardia was found in 18% and left sided fascicular ventricular tachycardia in 7.5% of the patients. Parahisian accessory pathway, atrial tachycardia and atrial flutter were found in minority of patients. Most of the paediatric patients (especially under 12 years of age) need general anaesthesia for better tolerability of the procedure.

Conclusion:

As the number of paediatric patients with tachycardia who need ablation is increasing, the set up and service of electrophysiological study and ablation should develop and expand in the paediatric hospitals.

AP19‐­00841

An alternative for transseptal puncture in patients without femoral accesses: The superior route

Silvia Guarguagli, Alessio Marinelli, Venkata Nagarajan, Ilaria Cazzoli, Sabine Ernst

Royal Brompton Hospital, UK

Introduction:

Complex congenital heart disease (CHD) patients represent a great challenge when catheter ablation procedures are required. Successful surgical corrections of complex substrates have brought to the growth of this unique population who requires unusual procedural techniques.

Methods:

We report a small series of consecutive procedures in which transseptal puncture (TSP) was performed via the jugular vein approach by a single operator in a tertiary centre from 2017 to 2019, using a radiofrequency (RF) needle.

Result:

Six catheter ablation procedures for atrial fibrillation (AF) (4, 67%) and left‐­ sided atrial tachycardia (AT) (2, 33%) were performed in three patients (mean age 45 ± 14 years, one male, mean weight 70 ± 17 kg). Two patients had an interrupted inferior vena cava with azygos continuation. One patient had bilaterally blocked femoral venous access due to previous multiple surgeries, surgically repaired coronary sinus/ASD and a mechanical mitral valve which excluded a retrograde approach. Therefore, we opted for a superior vena cava approach via jugular and subclavian vein access. Using the right jugular vein (5) and left jugular vein (1) we performed a single TSP using a combination of fluoroscopy, ultrasound and 3D electroanatomical mapping guidance with 3D depiction of the needle tip. To avoid the sliding of the needle off the fossa ovalis due to the deviate angle between the TSP needle and the septum, the needle was reshaped with an angle between 120 and 150°. In addition, we decided to use a RF needle (in combination with a SL1 sheath and epicardial steerable sheath) to lessen the necessary mechanical force to perforate the interatrial septum. All procedures were performed under general anaesthesia and using a 3D roadmap merge from either CT or CMR scan. In four cases, remote magnetic navigation was subsequently used. In one case, due to the impossibility to advance the sheath through a very calcified septum, a balloon dilatation was required. Left atrium access was gained in all cases, no complications occurred. Four procedures (66%) were acutely completely successful. Overall procedural time was 387 ± 79 minutes, with a median fluoroscopy time of 16 [8‐­26] minutes and median fluoroscopy exposure of 1442 [348‐­3007] μGy*m².

Conclusion:

Although technically challenging also for an expert operator, successful TSP can be safely performed via the superior jugular route and can be greatly facilitated by the use of a RF needle.

AP19‐­00938

Pediatric electrophysiology study and ablation at Beijing Children's Hospital—The first 15 years

Xia Yu

National Children's Medical Center, Beijing, China

Introduction:

To describe the development and current characteristics of pediatric electrophysiology and ablation at a large children's hospital in Beijing, China.

Methods:

Patient and procedural data was collected from a hospital database including demographics, procedural volume, substrate, acute and chronic success rate, as well as procedural cost. Descriptive statistics were used to analyze the data.

Result:

Case volume increased from 2 in 2003 to 246 in 2017. Treated patients were 59.0% ± 2.8% male. Patient age was 8.0 years ± 3.1 years (1.3‐­16.5 years). Weight was 35.7 kg ± 14.0 kg (9‐­94 kg). Congenital heart patients comprised 2.13% of the cohort. Most substrates were AVRT (38.5%) and AVNRT (29.0%). Asymptomatic bidirectional accessory pathways (WPW) were not ablated. Acute and chronic success rates were 90.4% ±5.6% and 87.2% ± 8.1%, respectively. There was no increase in either success rate over time (R ² = −.22). Fluoroscopy use decreased from a maximum of 133.73 minutes ± 34.0 minutes in 2006 to no fluoroscopy use since 2016. Computerized mapping was used regularly beginning in 2013. There were no major complications. Total per case cost converted from Chinese Yuan to US Dollar and normalized to 2017 US dollars was $6546 ± $607 ($5728 in 2004—$7412 in 2015). Similar procedures in the United States may cost $74 553 ± $1961.

Conclusion:

Pediatric ablation in Beijing, China is performed with increased volume though stable acute and chronic success rates. Cost of ablation is likely significantly less than that in the United States.

AP19‐­00993

Familial hypertrophic cardiomyopathy‐­10 caused by MYL2 de novo mutation: A case report and literature review

Zhenheng Ou, Lin Liu, Zong Liu

Shenzhen Children's Hospital, China

Introduction:

To summarize the clinical manifestations and gene mutations of familial hypertrophic cardiomyopathy‐­10 caused by MYL2 gene mutation with a case report and literature review.

Methods:

The clinical features of the patient who was admitted to the Cardiology Department in Shenzhen Children's Hospital in June 2019 and then diagnosed with familial hypertrophic cardiomyopathy‐­10 caused by MYL2 de novo mutation were analyzed. Related literature was searched at OMIM, PubMed, ClinVar, CNKI and Wanfang database (from the establishment of database to July 2019) by using “MYL2” and “hypertrophic cardiomyopathy” as keywords. The characteristics of MYL2 gene mutation and the clinical phenotype of children with familial hypertrophic cardiomyopathy‐­10 were summarized.

Result:

The boy, 2 years and 6 months old, was sent to hospital because of recurrent syncope. Electrocardiogram showed third‐­degree atrioventricular block. Cardiac hypertrophy with biatrial hypertrophy, pulmonary hypertension and tricuspid regurgitation were detected by echocardiography. Cardiac catheterization revealed the pressure of vena cava, right atrium, right ventricle and pulmonary artery to be significantly increased. A de novo heterozygous frame shift mutation of MYL2 gene exon7 (c.484G>A, p.G162R) was identified with whole exome‐­sequencing analysis. Left ventricular epicardial single chamber permanent cardiac pacemaker was implanted after diagnosed.

Conclusion:

This is the first case report of familial hypertrophic cardiomyopathy‐­10 with third‐­degree atrioventricular block as initial symptom caused by mutation of MYL2 gene in Chinese children.

AP19‐­01061

Multiple brain abscesses in a patient with double inlet left ventricle

Al ‐ Ma’ Arij Akbar Lubis

University of North Sumatra, Indonesia

Introduction:

Double inlet left ventricle (DILV) is a common form of univentricular atrioventricular connection. In most forms of DILV, The right ventricle is often small and both mitral and tricuspid valves open into enlarged left ventricle. The positions of the great arteries are reversed. This arrangement forces desaturated blood from the systemic venous system to pass through the RV and then return to the systemic circulation through the aorta without undergoing normal oxygenation in the lungs. Similarly, oxygenated pulmonary venous return passes through the LV and then back through the pulmonary artery to the lungs without imparting oxygen to the systemic circulation. In addition, there are defects in atrial and ventricular septa (ASD and VSD) following the DILV. Neglected cases will lead to some complications. Brain abscess is one of the frequent complications.

Methods:

The pathophysiology of this case is based on the right‐­to‐­left shunt present in CHD that allows bacteria colonizing the airway to pass through the cerebral circulation. In addition, the polycythemia that the patient developed leads to tissue hypoxia and ischemia that together with the viscosity of the blood, creates a niche for bacteria growth. Brain abscesses associated with CHD are typically caused by S.aureus and Streptococcus spp.

Result:

A 5‐­year‐­old patient was consulted to the neurosurgery department with the main complaint of headache and fever for three weeks with no histories of seizure nor vomitting. The head CT scan result was cerebral abscess in right and left fronto‐­temporo‐­parietal lobes. He was given ampicillin, ceftriaxone, and metronidazole by the pediatrician. The GCS score was 15. The body temperature was 38, 10C, the respiratory rate was 22 times in a minute. There was no motor deficit found. The lips, tongue, and fingertips were cyanotic. The clubbing fingers were found. The cardiac auscultation showed a 3/6 systolic murmur in pulmonic region, a 3/6 systolic murmur in left sternal border, a loud P2 sound. The chest X‐­ray showed cardiomegaly. The echocardiography showed double inlet ventricle, TGA, severe pulmonic stenosis, and large VSD. The haemoglobin count was 18.4 g/dL, leukocytosis was found (18 610/μL), and the hematocryte count was 60%. The neurosurgeon planned to perform a craniotomy for cerebral abscess aspiration.

Conclusion:

In this case, the cerebral abscess aspiration is only a life‐­saving procedure because the patient already developed a symptom of increased intracranial pressure which can reduce cerebral blood flow if it is neglected. The definitive therapy is still the total correction of the cyanotic CHD. This condition can reoccur as long as the cyanotic CHD is not corrected yet.

AP19‐­01067

Catecholaminergic polymorphic ventricular tachycardia and QT prolongation in a patient with a rare variant in the cardiac ryanodine receptor 2 gene

Kumiyo Matsuo, Hisaaki Aoki, Masayoshi Mori, Seiko Ohno, Minoru Horie

Osaka Women's and Children's Hospital, Japan

Introduction:

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an inherited genetic disorder. Ventricular tachycardia (VT) in CPVT typically occurs during exercise or at the time of emotional stress, and classically takes the form of bidirectional VT or ventricular fibrillation (Vf). QT interval is usually normal in CPVT patients. We report a case of an 8‐­year‐­old boy with a variant in RYR2 which is the major causative gene for CPVT. He presented both bidirectional VT during exercise and QT prolongation, overlapping clinical features of CPVT and Long QT syndrome (LQTS).

Methods:

We performed genetic analysis for 46 genes using targeted gene panel sequencing methods by next generation sequencer and confirmed the detected mutations by Sanger methods. We defined a mutation which was not identified in ethnic matched healthy controls and was judged as pathogenic by multiple prediction software.

Result:

Case presentation: An 8‐­year‐­old boy was referred to our hospital due to sinus bradycardia, atrial tachycardia, and exercise induced premature ventricular contractions (PVC). He did not have any episodes of syncope nor convulsions. He underwent the percutaneous pulmonary valvuloplasty when he was 4 months old. He did not have family history of any cardiac diseases or arrhythmias. At the age of 8 years, his resting 12 leads electrocardiogram showed the heart rate of 60 bpm and prolonged QTc (Bazzet QTc 513 msec). His Holter ECG showed supraventricular tachycardias (SVT) 57 times/d and bigeminal PVC provoking into bidirectional VTs. The exercise stress test exhibited bidirectional VTs and shortened QTc. He had the overlapping clinical features of CPVT and LQTS. A rare missense variant in RYR2 (c.5128C>A, p.H1710N) was detected without any other mutations or rare variants in known LQTS genes. After starting oral administration of nadorol and flecainide, the bidirectional VTs disappeared though SVT sometimes occurred. He has not experienced any syncopal episodes over the following 4 years.

Conclusion:

A patient having a missense variant in RYR2 showed CPVT phenotypes and prolongation of QT intervals. It has been reported that approximately 30% of CPVT cases have been misdiagnosed as concealed LQTS. As shown in this case, prolonged QT interval does not necessarily exclude the possibility of CPVT. In the future, the mechanism of the QT prolongation and clinical features of overlap syndrome should be clarified.

AP19‐­01091

Rapid right ventricular pacing in balloon aortic valvuloplasty in pediatric patients with congenital aortic stenosis

Ken‐Pen Weng

Kaohsiung Veterans General Hospital, Taiwan

Introduction:

Balloon aortic valvuloplasty is the better treatment for congenital aortic valve stenosis. The strong cardiac contractions and aortic flow cause rapid balloon movements during inflation and may lead to unsuccessful dilatation and aortic insufficiency. The aim of our study was to evaluate the effect of rapid right ventricular pacing in facilitating balloon stability during dilatation procedure for congenital aortic stenosis.

Methods:

Nine patients with congenital aortic stenosis were enrolled and managed with the balloon dilatation under rapid right ventricular pacing. Their ages ranged from 2 to 15 years, mean 9 ± 5.6 years. A pacing catheter was placed in right ventricle before balloon dilatation in all patients. Rapid right ventricular pacing was performed at a rate (up to 220/min) decreasing systolic aortic pressure to the point of half of baseline. Under continuous pacing, the balloon was inflated completely and deflated rapidly. Pacing was stopped after balloon deflation.

Result:

The systolic gradients across the aortic valve before procedure ranged from 50 to 163 mm Hg, mean 85.8 ± 45.5 mm Hg. The post‐­balloon dilatation gradients ranged from 35 to 138 mm Hg, mean 61.6 ± 43.6 mm Hg. Balloon stability at time of inflation was accomplished in all patients. Aggravation of aortic insufficient did not occur to any patient. There were no sustained arrhythmias or other procedure‐­related complications.

Conclusion:

Rapid ventricular pacing is a safe and effective method to provide balloon stability facilitating successful dilatation of congenital aortic stenosis and reducing the risk of complications.

AP19‐­01093

Clinical features and outcomes of radiofrequency catheter ablation for atrial flutter in children

Xiaomei Li, He Jiang

The First Hospital of Tsinghua University, China

Introduction:

To explore the clinical features of atrial flutter (AFL) in children and evaluate the efficacy and experiences of radiofrequency catheter ablation (RFCA) for AFL.

Methods:

Data were collected and analyzed on 50 consecutive pediatric patients (male 37/female 13) who underwent electrophysiology study and RFCA for AFL from February 2009 to November 2016. The average age was (6.2 ± 3.5) years and body weight was (23.7 ± 13.5) kg. The patients included 24 cases with congenital heart disease (CHD) and among them 22 had undergone repair surgery. The follow‐­up period was 1 month to 7 years after RFCA. Data were analyzed about clinical features of AFL and the outcomes of RFCA.

FIGURE Ablation and mapping in a case of AFL with post‐­op CHD Using CARTO electro‐­anatomy system. A, Right atrium in RAO. The red dots represent ablation lesions and the gray dots represent scar in CHD post‐­op. The yellow arrow shows the linear ablation of CTI and the white arrow shows the linear ablation of the bottom of scar to the inferior vena cava; B, Right atrium in LAO. The red dots represent ablation lesions and the gray dots represent scar in CHD post‐­op; C, ECG shows AFL with 2:1 conduction. The black arrow shows the normal atrium potentials; D, ECG shows AFL with 2:1 conduction. The black arrow shows the atrium scar potentials (fragmented and low‐­voltage waves).

Result:

Of these 50 children, 84% was persist AFL and 16% paroxysmal AFL. The occurrence rate of sick sinus syndrome (SSS) was 36% and there was no difference between the groups without CHD and with CHD (27% vs 46%, P = .2395). Of 49 children who underwent RFCA, the acute success rate was 96%, the follow‐­up recurrence rate was 8% .No complication of the procedures was observed during the follow‐­up period of 1 month to 7 years. The mechanism of AFL in the patients without CHD was the cavo‐­tricuspid isthmus (CTI)‐­dependent. However, in the children with CHD after the repair surgery, 10 (45%) cases was CTI‐­dependent AFL; 4 (8%) atrial scars‐­dependent AFL or 8(16%) both the mechanisms. There was no difference about the acute success rate (96% vs 100%, P = 1.0000) and the follow‐­up recurrence rate (21% vs 14%, P = .7008) between these two groups.

Conclusion:

RFCA was an effective and safe treatment for pediatric AFL. There was no difference on the acute success rate, the follow‐­up recurrence rate, as well as occurrence of SSS between the groups without CHD and with CHD. The mechanism in the children with CHD was involved in the CTI‐­dependent AFL, atrial scars‐­dependent AFL or both.

AP19‐­01113

Efficacy of the combination of R‐­wave synchronized atrial pacing and nifekalant infusion in children with postoperative junctional ectopic tachycardia

Masayoshi Mori, Hisaaki Aoki, Kazuhisa Hashimoto, Masaki Hirose, Kumiyo Matsuo, Yasuhiro Hirano, Youichirou Ishii, Kunihiko Takahashi, Futoshi Kayatani

Osaka Women's and Children's Hospital, Japan

Introduction:

Postoperative Junctional ectopic tachycardia (JET) occurs in children after congenital heart surgery and is sometimes difficult to manage with amiodarone (AMD) or beta blocker, which would cause hypotension and bradycardia. Nifekalant (NIF) infusion: pure Ikr blocker with weak positive inotropic effect, and R‐­wave synchronized atrial pacing (RSAp) are the treatment options of postoperative JET. The RSAp contributes atrioventricular (AV) synchrony by the atrial pacing triggered by the QRS wave. We aim to analyze the efficacy of the combination of NIF and RSAp.

Methods:

We enrolled four children with postoperative JET between 2015 and 2019, who were refractory to the usual treatment such as atrial overdrive pacing or AMD infusion. NIF infusion dose was 0.2‐­0.4 mg/kg/h while monitoring QT interval. The external temporary pacemaker (PACE 203, Osypka Medical GmbH, Germany) was used for RSAp. The atrial leads were connected to the ventricular ports of the pacemaker and the ventricular leads were connected to the atrial ports. The AV delay, post‐­ ventricular atrial refractory period, max tracking rate were adjusted manually according to the heart rate to achieve maximum increase in their arterial pressure by optimal AV resynchronization in each patient. We evaluated the efficacy and adverse events of the combination therapy with NIF and RSAp.

Result:

There were 1 boy and 3 girls with the age of 2 months to 1 year (median 2 months), who underwent the repair of AV septal defect (AVSD), AVSD with double outlet right ventricle, the LV‐­PA shunt with partial AVSD and hypo RV, and Norwood, RV‐­PA shunt with single ventricle. Their ventricular rates were 183‐­203 bpm. The RSAp was successfully applied in all patients and significant increased their systemic arterial pressure by mean 11 mm Hg (range 10‐­14 mm Hg). NIF decreased their ventricular rates by the mean 17 bpm (range 10‐­23 bpm) one hour after NIF infusion, by mean 32 bpm (range 10‐­45) three hours after NIF infusion. All patients was able to be managed with the usual atrial pacing (AAI mode) 12 hours (range 4‐­18 hours) after the initiation of RSAp. Though NIF was needed to be decreased due to mild prolongation of QTc (0.48 milliseconds), they did not have any hemodynamic deterioration or arrhythmic events.

Conclusion:

The Combination of RSAp and NIF Infusion was effective on the postoperative junctional ectopic tachycardia refractory to usual treatments.

AP19‐­01151

Clinical usefulness of the Rhythmia mapping for focal atrial tachycardia originating from the left atrial appendage: A case report

Keisuke Fukudome

Osaka City General Hospital, Japan

Introduction:

Rhythmia is a new mapping system using a 64 printed mini‐­electrodes small basket catheter (Orion). There are few reports about the usefulness of this system for pediatric arrhythmias.

Methods:

Sixteen‐­year‐­old boy was pointed out an arrhythmia at school heart screening. He presented infrequent PACs with negative P waves in lead I. Three and a half years after the initial diagnosis, he developed palpitations and exercise intolerance. At the annual check‐­up, he was diagnosed as incessant atrial tachycardia rated 110 bpm. His echocardiogram revealed mildly suppressed left ventricular systolic function.

Result:

We performed him radiofrequency catheter ablation under general anesthesia. After the transseptal puncture and angiography, we mapped the left atrium using Orion. The earliest activated site during tachycardia was the middle basal portion of the left atrial appendage. Although we tried to add more mapping point using the irrigated‐­ablation catheter, the tachycardia terminated easily with catheter‐­ induced mechanical trauma (bumping) when the catheter advanced into the appendage. We eventually ablated the small area of the earliest activated site of the tachycardia during sinus rhythm. There has been no recurrence for five months after the procedure.

Conclusion:

We had successfully ablated the atrial tachycardia originated from left atrial appendage using the Rhythmia mapping system. Orion, a uniquely designed expandable basket catheter, was useful for mapping in the small contractile chamber without bumping.

AP19‐­01168

The benefit of patent ductus arteriosus occlusion as the suggestive therapy in patient with co‐­exist atrial septal defect—Patent ductus arteriosus congenital heart disease (Case Report)

Wendy Wiharja

Universitas Pelita Harapan, Indonesia

Introduction:

Patent ductus arteriosus (PDA) and atrial septal defect (ASD) are both left‐­to‐­right shunt acyanotic congenital heart disease. A persistent PDA may delay closure of coexisting ASD due to volume loading and enlargement of the left atrium. Closure of PDA may prove benefit in reducing diameter of ASD.^1,2

Methods:

Case report: A Pre‐­term newborn delivered via C‐­section, birth‐­weight 1050 g, looked dyspneic and pale. APGAR score was 7/8. He was admitted to NICU and diagnosed initially with hyaline membrane disease. One month after admission, he failed to thrive and his symptoms worsened and he was intubated and given mechanical ventilation. On physical examinations: HR 130 bpm, RR 60x/m, temp 37.3°C. Chest radiography showed patchy infiltrates in the lungs. He was referred to cardiologist because congenital heart disease was suspected. Echocardiography was done, and it showed PDA ø 5 mm and ASD ø 2 mm, mild tricuspid regurgitation, EF 53%‐­77%. He was diagnosed with acyanotic heart disease (PDA and ASD). Captopril was given to the patient, and the patient was referred for further therapies.

Result:

Discussion: PDA with ø ≥ 5 mm, is commonly categorize as operable, on the other hand ASD with ø ≤ 5 mm is commonly closed itself without surgical treatment.^1,4 Co‐­existence of PDA and ASD may cause volume overload in left atrium and increase shunting from left to right heart, which decrease ASD closure, even though its ø ≤ 5 mm.^2,3 A study by Stapleton et.al investigate the natural history of ASD size in patients with a PDA, Following transcatheter PDA occlusion, ASD diameter decreased in 6 of 8 patients by a mean of 3.8 mm (±2.3 mm), including 2 that closed. The median duration of follow‐­up was 689 days. One ASD remained unchanged and 1 increased in size. The mean maximum ASD diameter decreased from 6.4 mm (±2.2 mm) to 3.9 mm (±3.4 mm) (P = .03).^1–3

Conclusion:

Following transcatheter PDA occlusion, small to moderate sized ASDs have significant probability to decrease in size, and possibly closed. In our patient, the condition of the co‐­exist PDA‐­ ASD is eligible for such approaching and should be suggested for his surgical procedure.

AP19‐­01179

Comparison of ross procedure versus non‐­ross procedure in children with congenital aortic stenosis who undergo aortic valve replacement—A systematic review

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

Universitas Pelita Harapan, Indonesia

Introduction:

Prevalence of Aortic Valve disease covers 6% of all congenital heart disease (3.8 of 10.000 births), and Aortic Stenosis is more prevalent (71%‐­86%). There are several surgical methods for this condition, like Aortic valve repair and Aortic valve replacement. This systematic review aims to compare incidence of re‐­operation, mortality, and survival rate between ROSS procedure and Non‐­ROSS Procedures.

Methods:

Searching was done in online resourced: PubMed, Google Scholar, and Science Direct. “PICO” was used as analytical design method, and all literatures will be filtered using inclusion and exclusion criteria.

Result:

There were 13 literatures from PubMed, 120 from Google Scholar, and 42 from Science Direct. After filtered using inclusion and exclusion criteria, 5 literatures were decided to be analyzed. Alsoufi et.al (2009): Re‐­operation on ROSS vs Mechanical (13% vs 6%). Mortality of ROSS vs Mechanical (2.3% vs 6.1%). Sharabiani et al (2016): Re‐­operation on ROSS vs Mechanical AVR vs Bioprosthetic AVR vs Homograft AVR (5.2% vs 8.2% vs 25% vs 41.5%). Survival rate of ROSS vs Mechanical AVR vs Bioprosthetic AVR vs Homograft AVR (97.3% vs 90.6% vs 92.6% vs 93.4%). Brown et.al (2016): Re‐­operation on ROSS vs Non‐­ROSS (28% vs 29%). Mortality of ROSS vs Non‐­ROSS (4% vs 17%). Survival rate of ROSS vs Non‐­ROSS (94% vs 81%). Wilder et.al (2015): Re‐­operation on ROSS vs AoV Repair vs Mechanical AVR (14.28% vs 28.% vs 26%). Khan et al (2013): Re‐­operation on ROSS vs AoV repair vs Homograft AVR vs Mechanical AVR vs Bioprosthetic AVR (4% vs 17% vs 36% vs 3% vs 0%). Mortality of ROSS vs AoV repair vs Homograft AVR vs Mechanical AVR vs Bioprosthetic AVR (2.9% vs 3.1% vs 7.7% vs 3% vs 0%)

Conclusion:

Systematical analysis from all 5 literatures showed differences in re‐­operation incidence, mortality, and survival rate, with superiority in ROSS procedure outweigh the Non‐­ROSS procedures.

AP19‐­01194

Empirically intraoperative cryoablation of right‐­sided accessory pathway during ongoing cardiopulmonary bypass for surgical repair in Ebstein's anomaly patient

Supaluck Kanjanauthai, Prakul Chanthong, Thaworn Subtaweesin

Faculty of Medicine Siriraj Hospital, Thailand

Introduction:

Performing ablation for accessory pathway (AP) in Ebstein's anomaly of tricuspid valve (TV) has been challenging due to various factors such as presence of multiple accessory pathways, difficulty interpreting complex and fractionated signals during mapping or difficulty stabilizing of ablation catheter. Intraoperative cryo‐­maze procedure has been performed as adjunctive treatment of atrial fibrillation or intra‐­atrial reentrant tachycardia but never been reported for accessory pathway ablation.

Methods:

N/A.

Result:

A six‐­year old girl, 17 kg who has severe Ebstein's anomaly of TV with moderate TV regurgitation and atrial septal defect (ASD). TV ring size was 46 mm. Her baseline EKG (Figure 1) showed sinus rhythm with ventricular preexcitation suggestive of right‐­sided AP. Plan for intraoperative ablation was pursued during surgical repair for TV and ASD closure. Pt went into unstable supraventricular tachycardia (SVT) after induction of anesthesia which required synchronized cardioversion. Right atrial incision was performed after cardiopulmonary bypass initiated. Right atrium was large with severe apical displacement of septal and posterior leaflet of TV. From EKG, prediction of AP site using delta wave axis putting our speculation to right posterior region or even in mid‐­cardiac vein due to negative delta wave in inferior leads and positive in aVL. However, delta wave axis interpretation could be complicated by possible presence of possible multiple APs. Coronary sinus opening and true TV ring along posterior border of TV were identified. Surgical cryoablation probe was pre‐­curved along patient's TV ring. Empiric one minute of near half‐­circled single application of cryo‐­energy was applied from lateral to coronary sinus os (6 o'clock) toward 11 o'clock marked of TV ring by excluding septal side of TV and Koch triangle area (Figure 2). After ablation, the remaining surgical repair of TV and ASD were proceeded. Post operative EKG showed normal sinus rhythm without ventricular preexcitation. No further postoperative SVT or evidence of antegrade conduction down AP after surgery and at one‐­ month follow up period (Figure 3).

Conclusion:

Empirical cryoablation of accessory pathway can be expeditiously and safely performed in young patient with relatively small heart size whom undergoing open heart surgery.

AP19‐­01196

Successful ablation for double‐­loop intra‐­atrial reentrant tachycardia utilizing ripple mapping in pediatric congenital heart patient

Sarin Lekchuensakul, Supaluck Kanjanauthai, Apichai Khongphatthanayothin

King Chulalongkorn Memorial Hospital, Thailand

Introduction:

Intra‐­atrial reentrant tachycardia (IART) is a common arrhythmia after surgical repair of congenital heart defects. Multiple IART circuits can be found in these complex patients. Therefore, to identify precise isthmus location of the circuit is crucial for aiding radiofrequency (RF) ablation. Ripple mapping is a novel method of 3D intracardiac electrogram visualization which could help displaying location of interest or channel for RF ablation. We report a case of post‐­operative congenital heart patient with successful RF ablation of double‐­loop IART using Ripple mapping.

Methods:

N/A.

Result:

A 9‐­year‐­old girl who underwent repair of Double Outlet Right Ventricle (Tetralogy of Fallot type) presented with palpitation and progressive dyspnea for 1 week. Baseline ECG showed IART, atrial rate 250 bpm with rapid ventricular response. Betablocker was introduced to control ventricular rate initially. EP study and RF ablation was performed after transesophageal echocardiogram yielded no intracardiac thrombus with mild degree of pulmonary stenosis and regurgitation, moderate tricuspid regurgitation, fair right ventricular function and borderline left ventricular function (LVEF 50%‐­55%). Anticoagulation was given throughout procedure as standard protocol. IART cycle length was 240 milliseconds. Ripple mapping was created with Pentaray catheter. Scar area was identified at inferolateral right atrial wall. Ripple map showed double‐­loop tachycardia consisting with counter‐­ clockwise loop around tricuspid valve annulus simultaneously with clockwise loop through inferolateral scar of right atrium (RA). Ripple map identified common slow conduction zone at inferolateral wall as shown in figure where two identified circuit circling pass each other. Delivery of single RF application using irrigated ablation catheter with energy of 30 watt resulted in instant termination of tachycardia. After RF application, there was no further inducible tachycardia. Left ventricular function was improved after restoration of sinus rhythm. After 8 months follow up, there has been no recurrence of IART.

Conclusion:

Multiple intra‐­atrial reentrant tachycardia circuit can be seen in complex congenital heart patient especially after surgical repair. Utilizing Ripple mapping or novel 3D intracardiac electrogram visualization can help locating precise slow conduction area or isthmus to be targeted for ablation.

AP19‐­01200

Management of incessant junctional ectopic tachycardia presenting as severe left ventricular dysfunction with Ivabradine

Nitin Parashar, Nitish Naik

All India Institute of Medical Sciences, New Delhi, India

Introduction:

Junctional ectopic tachycardia (JET) is an uncommon entity, seen in patients with structural heart disease or postcardiac surgery. It can rarely present in infancy in isolation as congenital JET. The management of this tachycardia remains very challenging for the cardiologists. Ivabradine is a new generation antiarrhythmic agent, acts by inhibiting funny current (If) in SA node, and has been recommended to treat coronary artery disease and congestive heart failure in certain situations. It has been used off‐­label in inappropriate sinus tachycardia and atrial fibrillation as well for the control of heart rate (HR). We treated one patient of severe left ventricular (LV) dysfunction due to incessant congenital JET with Ivabradine. This case is being presented here in view of rarity of arrhythmia and its successful management with non‐­invasive means.

Methods:

A 4‐­year old boy presented with poor feeding and restlessness since late infancy. Later he developed easy fatiguability, abdominal distension and shortness of breath. Parents also noticed abnormal pulsations in precordial area. He was found to have tachycardia, and received oral diuretics with some improvement in symptoms. Beta blockers and amiodarone had no effect on HR. His condition deteriorated in last one year with gross congestive heart failure (CHF). Physical examination revealed HR of 160 bpm with presence of S3, hepatomegaly and ascites. Electrocardiogram (ECG) of the patient showed narrow complex tachycardia with AV dissociation suggestive of JET (Figure 1a). Echocardiogram revealed left ventricular ejection fraction (LVEF) of 15%‐­20%. The attendants were unwilling for electrophysiological testing and radiofrequency ablation. Cautiously, patient was started on oral Ivabradine in the dose of 0.1 mg/kg/d divided in two doses along with a diuretic.

Result:

Six hours after the initiation of Ivabradine, his HR decreased to 138 bpm; and further came down to 97 bpm in 24 hours. ECG showed junctional rhythm with intermittent sinus beats. His Holter monitoring showed normal sinus rhythm with intermittent junctional ectopic rhythms with a rate of 70 bpm. Burden of accelerated junctional rhythm had also decreased to 35%. Echocardiogram after 4 weeks revealed significant improvement in LVEF (35%‐­40%). Then patient was continued on Ivabradine along with diuretic, beta blocker, ACE inhibitor and spironolactone. Follow up echocardiogram after 1 year showed normal LVEF (60%‐­65%) and 24 hr ECG monitoring showed intermittent junctional rhythm with adequate control of ventricular rate.

Conclusion:

Our patient had severe LV dysfunction and heart failure caused by incessant JET. We believe that control of HR was due to the effect of ivabradine, previously resistant to beta blockers and amiodarone. Early detection and timely treatment of JET with ivabradine can control the HR along with improvement in LV function.

AP19‐­01222

QRS‐­T angle predicts the ventricular dysfunction in Fontan patients

Ji Eun Ban

Ewha Womans University Seoul Hospital, South Korea

Introduction:

Patients with functional single ventricle have a risk of ventricular dysfunction. And a wide range of electrophysiolgic abnormalities tend to develop years after Fontan procedure. The spatial QRS‐­T angle, defined as the angle between the directions of ventricular depolarization and repolarization in 3‐­dimensional space, has been found associated with sudden cardiac death and other cardiac risks in multiple observational studies. The aim of this study was to validate the prognostic value of computer‐­ derived measurements of the spatial QRS‐­T angle from the standard 12‐­lead ECG in single ventricle after Fontan procedure.

Methods:

A total of 74 patients with functional single ventricle who underwent Fontan procedure were analyzed retrospectively. The independent measurements of the ECG variables including QRS‐­T angle in the 12‐­leads were undertaken using the Infinitt recording system. We categorized the study patients according their ventricular function as either the normal group (n = 63) or ventricular dysfunction group (n = 11).

Result:

In our analysis of ECG parameters, the spatial QRS‐­T angle (80.09 ± 42.43 vs 43.56 ± 30.49 milliseconds, P = .032) and QRS wave dispersion (19.4 ± 5.7 milliseconds vs 5.6 ± 2.9 milliseconds, P < .001) were significantly increased in the ventricular dysfunction group. However, spatial QRS –T angle was not significantly related to the risk of atrial tachycardia in the Fontan procedure.

Conclusion:

In our analysis of ECG parameters, the spatial QRS‐­T angle (80.09 ± 42.43 vs 43.56 ± 30.49 milliseconds, P = .032) and QRS wave dispersion (19.4 ± 5.7 milliseconds vs 5.6 ± 2.9 milliseconds, P < .001) were significantly increased in the ventricular dysfunction group. However, spatial QRS –T angle was not significantly related to the risk of atrial tachycardia in the Fontan procedure.

AP19‐­01227

Life‐­threatening flecainide toxicity related to alteration of milk feeding in an infant

Julia Zhuo Shi, Sit‐yee Kwok, Pak‐cheong Chow, Kin‐shing Lun, Tak‐cheung Yung

Queen Mary Hospital, Hong Kong

Introduction:

We describe an infant who developed life‐­threatening bradycardia with wide QRS complex secondary to flecainide toxicity. The predisposing factor was reduced milk feeding during an intercurrent illness.

Methods:

A 6‐­month‐­old boy with known atrial tachycardia well controlled with oral nadolol, amiodarone and flecainide, was hospitalized for viral gastroenteritis and reduced milk feeding for three days. ECG on admission showed sinus rhythm at 107 beats per minute. He was given oral rehydration salt for replacement of fluid loss. One day after admission, he developed acute onset of reduced responsiveness and pale looking. Clinical examination revealed hypotension, bradycardia and poor perfusion. 12‐­lead ECG showed isorhythmic atrioventricular dissociation, wide complex ventricular escape rhythm at 49 bpm with right bundle branch block pattern (Figure 1). Echocardiogram showed satisfactory ventricular contraction. He had significant metabolic acidosis with pH 7.03 and base deficit 14 mmol/L. Serum electrolytes were normal. He was immediately given fluid resuscitation, sodium bicarbonate infusion and inotropic support. All antiarrhythmic agents were discontinued. Over the following 24 hours, we managed to gradually wean off all inotropes. ECG was normalized after 30 hours (Figure 2). With ECG characteristics suggestive of flecainide overdose, serum flecainide level was taken at the time of acute deterioration. The flecainide level was 1.44 μg/mL (reference: 0.2‐­1.0 μg/mL), confirming flecainide toxicity. The drug prescription and administration were retrospectively audited by physician, nursing staff and pharmacist and confirmed not to be erroneous during his hospitalization. The pharmacokinetics of increased flecainide absorption due to reduced milk intake in this infant was the most appropriate explanation of flecainide toxicity in this case.

Result:

Flecainide is a common drug of choice for management of childhood tachyarrhythmias. Generally, it is administered in children without regard to food, although reduced drug absorption associated with milk feeding had been reported in infants. Monitoring of serum flecainide concentration with or without adjustment of drug dosage should be considered when there was reduction or withdrawal of milk intake in young infants treated with flecainide. Intriguingly, the presentation of flecainide toxicity was relatively late at the recovery phase of the intercurrent gastroenteritis. This may be explained by the long half‐­life of flecainide, resulting in high cumulative dose after four days of poor feeding.

FIGURE 1 12‐­lead ECG at onset of bradycardia showing isorhythmic atrioventricular dissociation and wide complex ventricular escape rhythm at 49 bpm with right bundle branch block pattern.

FIGURE 2 ECG strips (lead II) at hour 4 (top), hour 8 (middle) and hour 30 (bottom) of the event demonstrating gradual elevation of sinus rate, shortening of PR interval and shortening of QRS duration. Intermittent non‐­sustained short runs of ventricular tachycardia at rate of up to 150 bpm were noted at early phase of the event (top). There ECG was resumed to baseline after 30 hours (bottom)

Conclusion:

Flecainide toxicity is life‐­threatening and it could be inadvertently caused by increased absorption due to reduced milk feeding in infants. Paediatric cardiologists should be aware of this potential pharmacokinetic interaction and perform careful clinical and drug level monitoring pre‐­emptively.

AP19‐­01287

Pre‐­procedural AV nodal conduction disorders in atrial septal defect secundum patient, what should we keep in mind? A case report

Pramadya Mustafiza, Fera Hidayati, Erika Maharani

Gadjah Mada University, Indonesia

Introduction:

Atrial tachyarrhythmias are commonly seen in patients with ASDs, regardless of the type. AV block may be caused by injury to the conduction system during surgical ASD closure. Pre‐­ procedural AV nodal conduction disorders are rare with other ASD types.

Methods:

A 50‐­year‐­old woman presented to Cardiology Outpatient Clinic with dyspnea on effort and easily fatigue when doing heavy activities since last year. Physical exam was significant for right ventricular heaving and fixed‐­split second heart sound, and tricuspid regurgitation murmur. Transthoracic echocardiography revealed a secundum ASD with dilatation of both atrium and right ventricle. Subsequent transesophageal echocardiography revealed echo gap in the interatrial septum with diameter 17‐­27 mm. Right heart catheterization revealed a high flow low resistance of secundum ASD with mild pulmonary hypertension (mPAP 29 mm Hg). Then patient underwent percutaneous ASD closure. Unfortunately, the procedure was aborted because of unsuitable device's size and there were documented junctional rhythm with VPC frequent. The holter monitoring showed first degree AV block and 41% burden of multifocal VPC. CT cardiac revealed normal coronary arteries. From surgical conference, patient was planned to undergo surgical ASD closure with back up of temporary pacemaker.

Result:

Chronic left to right shunt associated with ASD increased hemodynamic load and geometric remodeling either cellular or macroscopic level. It caused electrical remodeling that could precipitate the development of tachyarrhythmias and conduction disorders. Different types of ASDs may also have a specific impact on the sinus node and or AV node depending on embryologic origin and anatomic proximity. Pre‐­procedural AV nodal conduction disorders are rare with other ASD types. It can be related to mutations in a family of closely‐­associated myocardial transcription factors such as NKX2.5, GATA4 and TBX5j gene whom commonly associated with secundum ASDs. The identification of specific gene mutation is practically important to predict the risk of progressive AV block and the requirement for pacemaker implantation during and after device closure. In this patient, genetical mapping has not been done yet because of lack of facilities. So, the patient still planned to go surgical ASD closure with back up of temporary pacemaker. The needed for permanent pacemaker implantation and electrophysiology study‐­ablation was determined from closed monitoring during ambulatory care.

Conclusion:

AV nodal conduction disorder in secundum ASD is rare and can be related with specific gene mutation. If there was a limitation in genetical mapping facilities, closed monitoring during ambulatory care can be alternative to evaluate the needed for either permanent pacemaker implantation or electrophysiology study‐­ablation.

AP19‐­01310

Pre‐­existing SND‐­AVND with high burden multifocal VPC in secundum atrial septal defect: PPM or ICD implantation after surgical closure?

Pramadya V. Mustafiza, Dyah Wulan Anggrahini, Erika Maharani, Fera Hidayati

Gadjah Mada University, Indonesia

Introduction:

Pre‐­existing conduction disorders with ventricular arrhythmias (VA) are most frequently seen in a patient with ostium primum ASD, but rare in other ASD types. Because of sudden death's risk in this population, early intervention with pacemaker implantation and or implantable cardioverter‐­defibrillator placement should be considered.

Methods:

A 50‐­year‐­old woman with secundum ASD was admitted for percutaneous ASD. Two months before admission, she was noted to have junctional rhythm albeit she did not complain of any specific cardiac symptom. Percutaneous closure was aborted because of unsuitable device's size and documented multifocal VPC frequent. Intermittent AV Block 2:1 and 41% burden of multifocal VPC were diagnosed in Holter monitoring after percutaneous procedure. On 6th August 2019, she underwent surgical closure with the placement of a temporary epicardial pacemaker. There was no residual shunt and complication during the surgery. Post‐­surgery ECG evaluation showed VPC bigeminy without junctional or AV Block. A week after surgery, the patient had PPM implantation.

Result:

Primarily right‐­sided volume overload in atrial septal defect (ASD) leads to electrical remodeling that might predispose patients to atrial tachyarrhythmia and conduction disorders. Conduction disorders and ventricular arrhythmia were rare in secundum ASD. In this patient, it can be one clinical entity caused by NKX2.5 gene mutation or even two different clinical entities. Actually, identification gene mutation is practically important to predict the risk of progressive AV block and the requirement for pacemaker or ICD implantation during or after closure. In this patient, genetically mapping has not been done yet because of lack of facilities. The profound consideration of PPM implantation, in this case, is due to documented SND on ECG surface. SND can be related to electrical and structural remodeling, but it remains irreversible although ASD, as an underlying structural problem, has corrected. Regarding VA, closed hemodynamic monitoring is conducted, hoping that improvement of right‐­sided over volume after ASD closure can reduce VPC burden. If the VPC burden was still high, EP study and ablation will be initiated. On the other hand, PPM replacement with ICD will be considered if there were documented sustained VA or cardiac arrest survivor.

Conclusion:

Pre‐­existing conduction disorders with ventricular arrhythmias (VA) are rare in the secundum ASD. Given the risk of sudden cardiac death in this population, PPM or ICD implantation should be considered.