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

Abstract

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.

Keywords: Bachmann's bundle; atrial fibrillation; catheter ablation; endocardial ablation; epicardial ablation.

Figure 1

Procedural workflow. The stepwise endo‐/epicardial atrial fibrillation ablation approach. Endocardial steps are represented in yellow boxes, whereas epicardial steps are represented in orange boxes. LA, left atrium; PVI, pulmonary vein isolation

Figure 2

Final lesion set. Typical final lesion set of the stepwise endo‐/epicardial atrial fibrillation approach; ablation lesions are represented as red tags (endocardial ablations) or rose tags (epicardial ablations). Endocardial biatrial maps are shown in gray (atrial walls), rose (pulmonary veins), or yellow (venae cavae), whereas epicardial map is semi‐transparent. (A) Left anterior oblique view; (B) antero‐posterior view; (C) biatrial postero‐anterior view; (D) right atrial postero‐anterior view

Figure 3

Survival free from atrial fibrillation/atrial tachycardia recurrence

Figure 4

European Heart Rhythm Association (EHRA) score during follow‐up. EHRA, European Heart Rhythm Association

Figure 5

Epicardial mapping and ablation of an atrial tachycardia originating from the Bachmann's bundle. Biatrial epicardial activation mapping of an atrial tachycardia appearing during the course of the stepwise endo‐/epicardial ablation, antero‐posterior view. Note that the site of earliest activation (red spot) is located epicardially, in the anatomical region of the Bachmann's bundle (A); radiofrequency energy delivery in that site resulted in atrial tachycardia termination (B)

Figure 6

Leftward approach to the transverse sinus. (A) Biatrial endocardial electroanatomical reconstruction, left anterior oblique view. Note that the ablation catheter (yellow) is located inside the transverse sinus in the anatomical position of the Bachmann's bundle (BB). The transverse sinus is accessed from the left, passing between the left atrial appendage (LAA) and the pulmonary veins. This access was feasible in 92% of the study cohort. (B) Low‐amplitude fragmented potential (black arrow), typically recorded on the Bachmann's bundle. (C,D) Left anterior oblique (C) and right anterior oblique (D) fluoroscopy projections, showing the ablation catheter inside the transverse sinus from the leftward approach. CS, coronary sinus