Randomized Trial of Segmental Versus Circumferential Antral Ablation in Paroxysmal Atrial Fibrillation

The goal is to complete ablation in all segments around the pulmonary veins until a circle of ablation lesions is created in the antrum with at least 30 seconds of ablation, 25W on the posterior surface, 30W on the anterior surface at each site, and change in the local electrogram. Entry and Exit block will be confirmed in each vein. The left superior pulmonary vein and left inferior pulmonary vein will be isolated with one circle, and the right superior and right inferior pulmonary veins will be isolated with one circle.

If the patient is in atrial fibrillation, ablation will begin in the segment with the highest frequency signals in the pulmonary vein antrum. If the patient is in sinus rhythm, mapping and ablation will occur during coronary sinus pacing. Segments with the earliest signals in the Lasso catheter will be targeted, and reassessed after each ablation lesion. This will continue in a segmental fashion on the antrum until pulmonary vein isolation is achieved. Lasso should be moved between veins between lesions to assess the earliest electrogram. Entry and exit block will be confirmed at each vein.