Abstract 18656: Characterization of Pulmonary Vein Reconnection in Repeat Procedures After After Initial Cryoballoon Ablation Identified With High Density Mapping

Abstract

Introduction: Catheter ablation of atrial fibrillation using the cryoballoon has become an alternate strategy to radiofrequency for pulmonary vein isolation (PVI). Both techniques, however, can result in pulmonary vein reconnection and the need for recurrent ablations. Objective: To study the incidence and specific location of pulmonary vein reconnection in patients with prior cryoballoon ablation for atrial fibrillation Methods: Retrospective analysis of patients that underwent radiofrequency ablation following a single initial cryoballoon PVI ablation was performed. Twenty patients were studied, all of whom underwent repeat ablation using radiofrequency with a mapping system (Rhythmia, Boston Scientific). A gap was defined as entrance conduction from the LA into the PV as suggested by the activation map. Results: Patients had an average of a 20 month period of normal sinus rhythm after initial ablation. A total of 48 gaps were identified in 18/20 patients (2.4 gaps per patient). The most common site of PV-LA conduction reconnection was at the superior pulmonary veins, specifically on the anterior portions. 60% (12/20) of patients had noted reconnection sites at the left superior pulmonary vein. All but one of these patients had gaps on the anterior surface of the vein. 75% (15/20) of patients were identified as having reconnection sites at the right superior pulmonary vein. All of these patients had gaps on the anterior surface of the vein. Less commonly, the left and right inferior veins each had 40% (8/20) patients with reconnection at these areas, with no consistent surface as the main site of reconnection. Further, 85% (17/20) patients had procedural ablation beyond only pulmonary vein re-isolation, owing primarily to the occurrence of atypical atrial flutters or atrial tachycardias that were seen during the repeat procedure itself Conclusion: Cryoballoon ablation is a successful technique for PVI in AF patients. However, reconnection of these sites is possible. Our analysis shows that the most common sites are at the anterior surface of the superior pulmonary veins. This could portend a potential drawback to be cognizant of during these initial procedures. Further analysis with a larger patient population will be necessary