Durability and reconnection patterns at time of repeat ablation after first-time pulmonary vein isolation by monopolar focal pulsed field ablation

Background Reconnection patterns and durability after pulmonary vein isolation (PVI) or cavotricuspid isthmus block (CTIB) using monopolar focal pulsed field ablation (FPFA) at repeat ablation have not previously been evaluated. Objective This study aimed to characterize electrophysiological findings during repeat procedures in real-world atrial fibrillation (AF) patients. Methods Patients undergoing repeat ablation (n=23) for symptomatic recurrent arrhythmias after first-time FPFA-guided PVI (n=212) between October 2022 and April 2026 underwent 3D high-density mapping and ad hoc re-ablation using radiofrequency or focal PFA. Results At index ablation, persistent AF was present in 13 of 23 (57%) patients, and CTIB was performed in 13/23 (57%). Mean time to repeat procedure was 379 ± 282 days. Complete durable PVI was observed in 11 of 23 patients (48%; 95% CI 27–69%), corresponding to durable isolation in 74 of 94 veins (79%; 95% CI 69–87%). Regular atrial tachycardia was the predominant mechanism for recurrence, occurring in 17 of 23 patients (74%; 95% CI 52–90%). Seventeen conduction gaps were identified, predominantly clustered in carina regions (13/17, 76%; p=0.002). Reconnection occurred exclusively ipsilaterally, without significant differences between veins (17%-26%, p=0.796). Durable CTIB was observed in 9 of 13 patients (69%; 95% CI 39–91%). After repeat ablation, 15 of 23 patients (65%; 95% CI 43–84%) remained free from atrial arrhythmia recurrence during 285 ± 204 days of follow-up. Conclusion Approximately half of patients demonstrated durable PVI at repeat procedures. Reconnection gaps clustered mainly in carina regions, highlighting the need for further studies evaluating chronic lesion durability after PFA.