Impact of Technique and Technology on Mitral Isthmus Ablation

Abstract

Mitral isthmus ablation is an established strategy in the treatment of peri-mitral atrial flutter and as an adjunct to pulmonary vein isolation. The objective of this review is to summarize the techniques and specific strategies that allow for increased success and durability of mitral isthmus ablation. Achieving bidirectional block across the mitral isthmus remains a challenge due to the increased thickness in this region, convective cooling as a result of coronary sinus blood flow, and the occurrence of epicardial connections. Several strategies to achieve durable mitral isthmus block, such as coronary sinus ablation, coronary sinus balloon occlusion, ethanol ablation via the vein of Marshall, and using alternate mitral lines in select cases, are described in detail in this review.