Background: Several reports have focused on repeat procedures after pulsed field ablation (PFA)–guided pulmonary vein isolation (PVI) for atrial fibrillation (AF). However, the electrophysiological characteristics of arrhythmia recurrence following balloon-in-basket (BiB)-PFA remain poorly understood.
Objective: To characterize pulmonary vein (PV) and left atrial posterior wall (LAPW) durability and mechanisms of arrhythmia recurrence during repeat procedures after BiB-PFA–guided ablation.
Methods: We retrospectively analyzed consecutive patients who underwent repeat ablation procedures for recurrent atrial tachyarrhythmias following initial BiB-PFA–guided ablation. During repeat procedures, all PVs and previously isolated LAPW regions were systematically assessed using high-density electroanatomical mapping. Reconnection distribution and arrhythmia mechanisms were evaluated.
Results: A total of 12 patients (median age 75 years, 33% female, 25% paroxysmal AF) undergoing repeat procedures after BiB-PFA–guided ablation were included. Durable isolation of all PVs was observed in 9 patients (75%). At PV level, 45/48 PVs (94%) remained isolated at repeat electrophysiological study. When reconnection was present, conduction gaps were limited and focal rather than extensive circumferential reconnection. Gap distribution analysis demonstrated localized reconnection at the anterior or posterior aspects of the left-sided PVs. Among 4 patients who underwent additional LAPW isolation during the index procedure, durable LAPW isolation was observed in 2 (50%). Arrhythmia recurrence was characterized predominantly by organized atrial tachycardias and substrate-related mechanisms despite preserved PVI.
Conclusions: Repeat procedures following BiB-PFA demonstrated highly durable PVI with limited focal reconnection, whereas LAPW isolation showed limited durability. Recurrent atrial tachyarrhythmias frequently reflected non-PV substrate-related mechanisms rather than widespread lesion failure.
