Atrial Fibrillation Ablation: Location, Location, Location

摘要

Over the last decade, a potpourri of techniques has been used for catheter ablation of atrial fibrillation. These have included targeted approaches based upon electrophysiologic findings and predominantly anatomic approaches. The basic approaches include elimination of focal triggers/tachycardia from the pulmonary veins (pulmonary vein isolation) or other sites and substrate modification. Generally, substrate modification has included wide area circumferential ablation around the pulmonary veins with additional linear ablation at various sites. Elimination of vagal reflexes and/or complex fractionated electrograms has also been incorporated into the ablation regimens in some laboratories. There are multiple reports in the literature with these varying approaches. It is interesting that even laboratories that report performing the "same" technique can report disparate results. WHY?While this question has many potential answers, this editorial will use the data presented by Liu et al.to propose some technical issues that may play an important role in the different outcomes reported from different laboratories. Liu et al.1 performed a randomized comparison between two approaches to pulmonary vein isolation following an attempt at circumferential pulmonary vein (CPVA) or wide area ablation. An impressive advantage was noted to the approach that attempted to close conduction gaps along the contour of previously delivered lesions versus targeted ablation at the os of the pulmonary veins. Specifically, CPVA followed by targeted ablation at the os of the pulmonary veins (M-CPVA) was associated with a 42% rate of late recurrence compared with 18% in those patients in whom further lesions were delivered on the contour of lesions already registered by the CARTO system, but also targeted to achieve pulmonary vein isolation (A-CPVA). An important feature of the initial CPVA was "continuity of circular lesions and voltage abatement at the time of RF application at each site." The initial CPVA resulted in complete pulmonary vein isolation in only nine of the original 109 patients. Of the 100 patients included in the randomized study, approximately 50% of the patients had either the right or left pulmonary veins isolated with the initial CPVA. As noted by the authors, other groups have reported different results with the "same" technique.