Background: Pulsed field ablation (PFA) yields a novel ablation technology for atrial fibrillation (AF). PFA lesions promise to be highly durable, however clinical data are still limited.

Objective: This study sought to investigate intraprocedural findings in patients undergoing PFA. 

Methods: Consecutive AF patients underwent PFA-based pulmonary vein isolation (PVI) using a multispline catheter. Additional ablation, including left atrial posterior wall isolation (LAPWI) and mitral isthmus isolation (MI) were performed in a subset of persistent AF patients. The PFA catheter is a 12-F over-the-wire device with 5 splines that each contain 4 electrodes, available in two sizes representative of its maximal diameter: 31 and 35mm. The catheter can be configured into different shapes (a basket or a flower configuration) for energy delivery. PVI was performed in all patients using at least 8 applications at an output of 1.9 kV (4 basket, 4 flower configuration).

Results: In 20 patients, acute PVI was achieved in 80/80 PVs, LAPW isolation in 9/9 patients, MI isolation in 2/2 (procedure time: 123±21.6minutes, fluoroscopy time: 19.2±5.5minutes). Left atrial PFA catheter time was 49.0 ± 13.7 minutes with longer LA-PFA times in patients receiving additional ablation with 58.3 ± 14.5 versus 41.5 ± 7.0 minutes in PVI only patients (P = 0.0015). PFA applications in total (median of 8 per PV) were utilized to isolate all 80 PVs in 20 patients (including 2 left common PV ostia (LCPV), 2 right middle PVs). After the initial 8 applications, four left superior PVs (including 1 LCPV) were not isolated (demonstrated with PFA catheter) and either isolated after ablation of the ipsilateral inferior PV (n=3) or with additional 4 PFA applications (n=1). In 10 PVs (5 RSPVs and 5 RIPVs) only one PFA catheter configuration (either flower (n= 8) or basket only (n= 2)) was applied due to limitation of catheter movement/placement. After this initial ablation, all 80 PVs were checked to confirm isolation. One transient coronary spasm with ST-elevation, occurred directly after MI-ablation in one case. There were no further complications (no pericardial tamponade, no access complication, no stroke).

Conclusion: Regarding acute success, PFA in patients undergoing catheter ablation for AF seems to be safe and efficient.