Introduction Pulmonary vein isolation (PVI) is an established treatment for atrial fibrillation (AF), and high-power, short-duration (HP-SD) radiofrequency ablation has been reported to be effective. Since the depth of the myocardial scar created by HP-SD ablation can be shallower than that of conventional middle-power, middle-duration (MP-MD) ablation, which might be a partial limitation of HP-SD ablation, we investigated the differences between HP-SD and MP-MD ablation. Methods and Results A total of 158 patients who underwent lesion size index-guided PVI were enrolled. The first half of the consecutive patients (n=83) underwent MP-MD ablation, while the second half (n=75) underwent HP-SD ablation. The PVs on both sides were divided into six segments of anterior, posterior, roof, bottom, and on the anterior and posterior of the carina. The patient characteristics, procedure features, remnant and early reconnections (RERs) of PV conduction after initial PVI, and clinical outcome were compared between the groups. The procedure time was significantly longer in the MP-MD group than in the HP-SD group (176.9 ± 56.0min vs. 132.1 ± 45.9min, respectively, p<0.001). The rates of RER at the right anterior carina was significantly less frequent in the MP-MD group than in the HP-SD group (12.1% vs. 25.3%, respectively, P=0.04). The cumulative recurrence rate expressed in the Kaplan-Meier curve was comparable between the MP-MD and HP-SD groups. Conclusions Each method showed distinguished features. Combination use of MP-MD and HP-SD depending on the segment of the PV, especially the right PV anterior carina, may be reasonable.
