Residual tiny pulmonary vein potentials on high-resolution mapping after pulsed field ablation predict atrial arrhythmia recurrence and poor durability of pulmonary vein isolation.

BACKGROUND: Pulsed field ablation (PFA) enables safe and efficient achievement of acute pulmonary vein isolation (PVI), with apparent elimination of pulmonary vein potentials (PVPs) as assessed by the relatively coarse electrogram evaluation using single-shot PFA ablation catheters. Nevertheless, late-phase left atrium-pulmonary vein (LA-PV) reconnection remains a clinically relevant issue. OBJECTIVE: The study aimed to elucidate the potential role of residual tiny PVPs observed on high-resolution mapping after the elimination of overt PVPs by single-shot PFA for the prediction of atrial arrhythmia recurrence and late-phase LA-PV reconnection. METHODS: This retrospective observational study included patients who underwent an initial ablation for atrial fibrillation (AF) using a single-shot PFA device, and were evaluated with high-resolution mapping immediately after ablation. Residual tiny PVPs were defined as low-amplitude electrograms with a bipolar voltage ≥0.03 mV. Patients were followed for 1 year to assess AF or atrial tachycardia (AF/AT) recurrence. In patients undergoing repeat ablation for recurrent atrial arrhythmias, the spatial relationship between residual tiny PVPs identified at the initial ablation and late-phase LA-PV reconnection. RESULTS: Among 158 patients, residual tiny PVPs were identified in 48 (30%). The presence of residual tiny PVPs was significantly associated with AF/AT recurrence during 1-year follow-up (hazard ratio, 2.68; 95% confidence interval, 1.14-6.31; p=0.024). Among 15 patients undergoing repeat ablation, 81% of residual tiny PVPs sites showed locational concordance with late-phase LA-PV reconnection. CONCLUSION: Residual tiny PVPs detected by high-resolution mapping after PFA predict 1-year AF/AT recurrence and precede clinically significant LA-PV reconnection.