Electrophysiological findings during re-do procedures after single-shot pulmonary vein isolation for atrial fibrillation with pulsed field ablation

FUNDING ACKNOWLEDGEMENTS: Type of funding sources: None. BACKGROUND: Pulsed field ablation (PFA) is a novel non-thermal ablation modality which applies electroporation to destabilize the cell membranes, leading to selective ablation of the atrial myocardium whilst sparing surrounding tissues and structures. It’s discriminating nature and potential for minimal adnexal injury opens new, promising horizons into catheter ablation of AF. However, one of the major issues to address is long-term results of the technique. PURPOSE: To investigate the electrophysiological findings and type of arrhythmias during redo-ablation in 15 patients who underwent pulmonary vein isolation (PVI) for atrial fibrillation (AF) using single-shot PFA. METHODS: We investigated patients who underwent redo-ablation due to occurrence of AF/ atrial flutter (AFL) or tachycardia (AT) following initial PVI with PFA. We report the electrophysiological findings and ablation strategy during redo-ablation. RESULTS: Out of 447 patients undergoing index PVI with PFA, 15 patients (age: 61.8±10.4 years; 8 (53%) males; left atrial volume index (n=10): 39.4±14.6 mL/m2) were referred for redo-ablation after index PFA. Indication for the index ablation was paroxysmal-AF in 8 patients, persistent-AF in 6 and long-standing-persistent-AF in one patient. Mean time-to-recurrence was 5.0±1.8months. Three patients received additional posterior-wall-isolation during index PFA. Thirteen (85%) patients suffered AF recurrence and 5/13 had concomitant AFL. In the remaining 2 patients, one had a recurrence of (box-dependent) AFL, and one had AT. No patients had all PVs reconnected. Reconnection in zero, one, two or three PVs was found in 33%, 20%, 20%, and 27% of patients, respectively. All 7 patients with zero or one reconnection with AF recurrence received additional/repeat posterior-wall-isolation during re-ablation, while in the others PVs were re-isolated. In 1/3 patients who had posterior-wall ablation during index PFA, durable isolation of the posterior wall was confirmed during re-do procedure. Patients with only AFL/AT had no reconnection of PVs, and the substrate was successfully ablated. CONCLUSION: We observed durable PVI in 62% of the PVs in patients with AF/AFL recurrence after PFA PVI. In one-third of patients all PVs were isolated. The predominant recurrent arrhythmia following PVI-only was AF. Concomitant (33%) or isolated (14%) AFL/AT recurrence was observed in 47% of patients. [Figure: see text]