The Last Shot for “One Shot” Pulmonary Vein Isolation with Radiofrequency Energy?

Abstract

Editorial CommentCurrent practice guidelines recommend catheter ablation to maintain sinus rhythm in patients with symptomatic, paroxysmal, atrial fibrillation (AF) who have failed treatment with an antiarrhythmic drug. 1 Based on the observation that triggers that initiate AF usually emanate from within the pulmonary veins (PVs), ablation strategies that target the PVs and/or PV antrum to an endpoint of PV isolation (PVI) are considered the cornerstone for most AF ablation procedures. 2 Currently, PVI can be achieved by delivery of point-to-point radiofrequency (RF) energy or as a "one shot" technique with a cryoenergy balloon system; both techniques are associated with a similar long-term efficacy. 3,4 Virtually all ablation laboratories make use of an 8-20 pole circular mapping catheter positioned at the PV ostium to demonstrate or confirm successful PVI after energy delivery. Potentials from the PVs have distinct characteristics yet must be distinguished from far-field atrial electrical signals originating in neighboring structures. Mapping and catheter manipulation is usually facilitated by integration into a 3dimensional (3-D) electroanatomic mapping system. The use of point-by-point RF requires acquisition of an experiential skill set and procedures can be time consuming. In particular, creating circumferential lesions that are contiguous and transmural is challenging, but is required to achieve durable PVI for most ablation strategies. Thus, there has been a long-standing interest in developing a single catheter capable of both mapping and ablating the PV ostia/antra using RF energy.The PV ablation catheter or PVAC (Medtronic, Inc., Carlsbad, CA, USA), capable of independently delivering nonirrigated, duty-cycled, RF energy in various combinations of unipolar and/or bipolar current, was a multipolar ablation catheter that attempted to achieve these valuable goals. The PVAC isolation technique demonstrated significantly shorter procedure and fluoroscopy times, without the