Abstract
Background
Catheter ablation for atrial tachycardia (AT) originating from the atrial appendage can be challenging, and it carries a risk of complications.
Case Summary
A 65-year-old woman with drug-refractory AT originating from the base of a bifid right atrial appendage underwent a hybrid procedure after failed radiofrequency ablation. Via minithoracotomy, the earliest activation site was visually identified and successfully ablated under direct vision using unipolar electrocautery, resulting in immediate termination and noninducibility. The patient remained asymptomatic in sinus rhythm at the 1-month follow-up.
Discussion
Direct visual unipolar electrocautery via minithoracotomy is a safe and effective alternative to appendage ligation or resection for managing challenging right atrial appendage–origin AT.
Take-Home Messages
A minimally invasive surgical approach with direct visual electrocautery is a safe and effective therapeutic alternative for challenging appendage-origin AT. This technique should be considered when percutaneous ablation is unsuccessful or high risk.
Key words: ablation, atrial tachycardia, thoracotomy
Graphical Abstract
History of Presentation
A 65-year-old woman was admitted with a 6-year history of recurrent palpitations. The episodes occurred without obvious triggers and were exacerbated by physical activity or emotional stress. Previous treatment with metoprolol sustained-release tablets and Shensong Yangxin capsules had been ineffective.
Past Medical History
The patient had no history of hypertension, diabetes mellitus, coronary artery disease, or prior surgical interventions.
Differential Diagnosis
The patient presented with incessant atrial tachycardia (AT), requiring differential diagnosis from other tachyarrhythmias such as sinus tachycardia, supraventricular tachycardia, and atrial flutter.
Investigations
Echocardiography revealed an ejection fraction of 56%, with right atrial dimensions of 37 mm (transverse) and 46 mm (longitudinal). Ambulatory electrocardiogram (ECG) monitoring demonstrated incessant tachycardia with a jump phenomenon (Figure 1A). Surface ECG was consistent with AT (Figure 1B).
Figure 1.
Initial Ambulatory and Surface ECGs and First Radiofrequency Ablation Procedure
(A) The sudden PR interval prolongation during atrial tachycardia suggests the presence of dual atrioventricular nodal pathways (denoted by ※). (B) ECG suggests atrial tachycardia, with P-wave morphology similar to sinus rhythm. (C) During the initial radiofrequency ablation procedure, the earliest activation site of the atrial tachycardia was mapped to the base of the right atrial appendage. ECG = electrocardiogram.
Management
During the initial procedure, activation mapping confirmed a right atrial appendage (RAA) origin of the AT, with alternating conduction through the slow pathway intermittently. After slow pathway modification, radiofrequency energy was delivered at the earliest activation site, resulting in termination of AT. However, tachycardia remained inducible, either spontaneously during observation or with isoproterenol infusion (Figure 1C). Medical therapy was subsequently attempted.
One year later, the patient was readmitted owing to recurrent symptoms. ECG showed AT with identical morphology to the previous episode. After multidisciplinary consultation, a combined surgical and electrophysiological approach was planned. Intraoperative mapping again confirmed the RAA origin of the AT (Figure 2A). Via a minithoracotomy through the right fourth intercostal space between the anterior and midaxillary lines, the RAA was exposed. The ablation catheter was positioned at the earliest activation site, located at the base of junction between 2 lobes of the appendage, where a whitish abnormal structure was visually identified (Figure 2B). Under direct vision, the surgeon performed unipolar electrocautery ablation at this site using an electrocautery knife, resulting in immediate termination of AT. The ablated area was subsequently sutured. Programmed electrical stimulation with and without isoproterenol infusion failed to reinduce tachycardia.
Figure 2.
Second Ablation Procedure and Follow-Up ECG
(A) Mapping results during the second procedure. (B) Upon cardiac exposure via a minithoracotomy, the earliest activation site was identified, corresponding to the basal interlobar region of the atrial appendage, where a distinct whitish area was observed (green circle). (C) Follow-up ECG at 1 month postoperatively. ECG = electrocardiogram.
Outcome and Follow-Up
At the 1-month follow-up, the patient reported complete resolution of palpitations. ECG showed sinus rhythm (Figure 2C), and ambulatory ECG monitoring revealed no significant arrhythmias.
Discussion
Achieving satisfactory outcomes after radiofrequency ablation for AT originating from the atrial appendage is often challenging given the significant risks involved, and surgical intervention may be necessary for some cases with deep-seated origins or higher risks. Surgical management options for AT originating from the atrial appendage include appendage ligation or resection,1 as well as thoracoscopic bipolar radiofrequency ablation or ligation.2,3 However, these techniques alter cardiac anatomy, and ligation may not be suitable for all appendage origins. In the current case, the AT focus was located near the base of a bifid RAA, making ligation technically difficult. This report presents to our knowledge the first case of successful unipolar electrocautery ablation under direct vision via a minithoracotomy for RAA-origin AT. The procedure is straightforward, safe, and effective, representing a valuable approach worthy of broader adoption.
Conclusions
Unipolar electrocautery ablation under direct vision via a minithoracotomy is an effective therapeutic strategy for managing AT originating from the appendage.
Funding Support and Author Disclosures
The authors have reported that they have no relationships relevant to the contents of this paper to disclose.
Take-Home Messages
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A minimally invasive surgical approach with direct visual electrocautery is a safe and effective therapeutic alternative for challenging appendage-origin AT.
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This technique should be considered when percutaneous ablation is unsuccessful or high risk.
Footnotes
The authors attest they are in compliance with human studies committees and animal welfare regulations of the authors’ institutions and Food and Drug Administration guidelines, including patient consent where appropriate. For more information, visit the Author Center.
References
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