Acute e chronic feasibility of left atrial appendage isolation focal ablation catheter toggling between radiofrequency and pulsed field energy

Background Electrical isolation of the left atrial appendage (LAA) has been shown to reduce arrhythmic recurrence in patients with long standing atrial fibrillation (AF); however, durable isolation remains a challenge. Purpose to demonstrate acute e chronic feasibility of LAA isolation in persistent AF patients with a focal ablation catheter toggling between radiofrequency (RF) and pulsed field energy (PFA). Methods We prospectively enrolled consecutive patients undergoing first-time persistent AF ablation with the lattice-tip PFA catheter between November 2024 and September 2025. Patients were divided int three groups according to the LAA ablation strategy at the ostium: 1) PFA 4 seconds only, (2) RF for 5seconds, 70% power, and (3) RF for 7 seconds, 90% power. The acute feasibility endpoint was LAA isolation defined as entrance and exit block after a 20-minute waiting period. Chronic feasibility was assessed as persistent LAA isolation during the LAAO procedure 3 months post-ablation. Results A total of 182 (113, 62% males) patients were included in the analysis. A total of 78 (42.8%), 43 (23.7%), and 61 (33.5%) patients were included to Groups 1, 2, and 3, respectively. All received PFA within the LAA body. Acute LAA isolation was achieved in all (100%) in both groups. All patients underwent repeat mapping during LAA closure after 3 months. LAA reconnection was observed in 78 (100%)patients in Group 1, 35(81.4%) in Group 2, and and none (0%) in Group 3 (p<0.001). Conclusion Acute LAA isolation with the lattice-tip PFA catheter was feasible across all strategies. However, in this cohort, PFA alone did not provide durable isolation, indicating that additional RF energy appears necessary to achieve chronic LAA isolation.