Comparison of Cryoablation and Radiofrequency Ablation Areas Demarcated by Postprocedural Electroanatomic Mapping in Patients with Atrial Fibrillation Treated by Pulmonary Vein Isolation

Abstract

Background: Circumferential pulmonary vein isolation (CPVI), achieved by cryoballoon ablation (CBA) or by irrigated-tip radiofrequency catheter ablation (RFA), has been used to isolate the area surrounding the pulmonary veins (PVs) in patients with paroxysmal atrial fibrillation (AF). Although studies have shown circumferential RFA to be comparable to CBA in terms of arrhythmia-free survival and the overall complication rate, there has been no reported comparative quantification of the resulting acute ablated areas of the left atrial endocardial surface. Therefore, we conducted such a study. Methods and Results: The study involved 40 patients (32 men, 8 women; mean age, 62.2 ± 10.4 years) who were undergoing CBA or circumferential RFA for AF (paroxysmal AF, n = 24; persistent AF, n = 16). A detailed 3-dimensional electroanatomic map of the left atrium (LA) was created and merged onto the pre-procedural computed tomography (CT) of the LA, and the ablation areas, interpreted as low voltage areas, were quantified and compared between the 2 CPVI methods. The low voltage areas were significantly larger in the CBA patient group than in the circumferential RFA patient group (40.6 ± 13.8 vs. 31.46 ± 15.8 cm², respectively, ρ = 0.00287). Conclusions: Our acute phase data indicate that CBA produces a larger PV-LA surface isolation area compared with point-by-point circumferential CF-based RFA.