Background: High power short duration (HPSD) ablation for pulmonary vein isolation (PVI) in patients with atrial fibrillation (AF) has demonstrated improved linear continuity of lesions. HPSD may also be an efficient strategy for atrial linear ablation.

Objectives: To evaluate the feasibility, procedural data, lesion characteristics and the safety of anterior line (AL) and roof line (RL) ablation by using HPSD (50 W) technique.

Methods: 35 consecutive patients with macro-reentrant left atrial tachycardia (LAT) or substrate at LA anterior wall or roof after previous PVI were enrolled. They underwent AL or RL ablation or both with contact‐force catheters. Ablation power was set to 50 W, targeting AI values of 500 for AL and 400 for RL. First-pass conduction block (FPB) after a single set of linear lesions was evaluated as an indicator of efficacy of our AI guided point-by-point ablation. The AL was arbitrarily divided into 3 (caudal, middle and cranial) segments to analyze the location of conduction gaps in non-FPB patients.

Results: A total of 32 AL and 17 RL were deployed and FPB was achieved in 24 (75%) and 14 (82%) of them respectively. In the non-FPB group, the most frequent gap location along the AL was the middle third. Final bidirectional block of AL was achieved in 97%, and bidirectional block of RL was achieved in 100%. The RF ablation time was short (2,9 ± 0,8 min for AL and 46,2 ± 15,6 sec for RL). For AL, female gender was significantly more frequent in FPB than in non-FPB patients (p 0,028); patients with non-FPB were associated with significantly longer RF time as compared to patients with FPB (204 ± 47 sec vs 161 ± 41 sec; p = 0,02). No procedural complications occurred.

Conclusion: AI guided HPSD (50 W) ablation appears to be a feasible, effective and fast technique for AL and RL ablation.