Adjunctive percutaneous ablation targeting epicardial arrhythmogenic structures in patients of atrial fibrillation with recurrence after multiple procedures

Current Understanding of Atrial Fibrillation Recurrence After Atrial Fibrillation Ablation: From Pulmonary Vein to Epicardium

Recurrence of atrial fibrillation (AF) after catheter ablation is common, with pulmonary vein (PV) reconnection considered the most likely cause. However, technologies such as contact force-sensing, irrigated catheters, and ablation index (AI)-guided ablation strategies have resulted in more durable PV isolation. As a result, it is difficult to predict which patients will develop AF recurrence despite durable PV isolation, with evolving non-PV atrial substrates thought to be a key contributor to late recurrences. Deciphering the complex mechanisms of AF recurrence beyond the cornerstone of PV isolation therefore remains challenging. Recently, there have been several important advances that may lead to better understanding and treatment of this challenging clinical entity: percutaneous epicardial access and mapping, late gadolinium enhancement magnetic resonance imaging (LGE-MRI), improvements in high-resolution electroanatomic mapping, and new ablation energy sources, specifically pulsed-field ablation. This review aims to synthesize the current literature in an effort to better understand arrhythmia mechanisms and treatment targets in patients with AF/Atrial tachycardia (AT) recurrence post-ablation. This article is protected by copyright. All rights reserved.

Stepwise endo-/epicardial catheter ablation for atrial fibrillation: The Mediterranea approach

Background

Outcomes of catheter ablation (CA) among patients with nonparoxysmal atrial fibrillation (AF) are largely disappointing.

Objective

We sought to evaluate the feasibility, effectiveness, and safety of a single‐stage stepwise endo‐/epicardial approach in patients with persistent/longstanding‐persistent AF.

Methods

We enrolled 25 consecutive patients with symptomatic persistent (n = 4) or longstanding‐persistent (n = 21) AF and at least one prior endocardial procedure, who underwent CA using an endo‐/epicardial approach. Our anatomical stepwise protocol included multiple endocardial as well as epicardial (Bachmann's bundle [BB] and ligament of Marshall ablations) components, and entailed ablation of atrial tachycardias emerging during the procedure. The primary outcome was freedom from any AF/atrial tachycardia episode after a 3‐month blanking period. The secondary outcome was patients' symptom status during follow‐up.

Results

The stepwise endo‐/epicardial approach allowed sinus rhythm restoration in 72% of patients, either directly (n = 6, 24%) or after AF organization into atrial tachycardia (n = 12, 48%). BB's ablation was commonly implicated in arrhythmia termination. After a median follow‐up of 266 days (interquartile range, 96 days), survival free from AF/atrial tachycardia was 88%. Antiarrhythmic drugs could be discontinued in 22 patients (88%). As compared to baseline, more patients were asymptomatic at 9‐month follow‐up (0% vs. 56%, p = .02). Five patients (20%) developed mild medical complications, whereas one subject (4%) had severe kidney injury requiring dialysis.

Conclusion

A single‐stage endo‐/epicardial CA resulted in favorable rhythm and symptom outcomes in a cohort of patients with symptomatic persistent/longstanding‐persistent AF and one or more prior endocardial procedures. Epicardial ablation of BB was commonly implicated in procedural success.

Epicardial Ablation of Supraventricular Tachycardias

Supraventricular arrhythmias are the most common cardiac arrhythmias encountered; however, it is uncommon that supraventricular tachycardias require percutaneous epicardial access for successful mapping and ablation. There are particular scenarios where epicardial access and ablation should be considered. Certain accessory pathways particularly in the posteroseptal region may require epicardial access for successful ablation. These pathways may also be approached from within the coronary sinus system. In addition, tachycardias near the phrenic nerve in the right atrium or left atrium may require epicardial access for successful ablation or to allow displacement of the phrenic nerve facilitating safe catheter ablation.