Impact of Irrigated Versus Nonirrigated Ablation on Lesion Size, Geometry, and Potential Collateral Injury
(A) Ablation lesions delivered under power control with nonirrigated catheter (left) and irrigated catheter (right). Nonirrigated power controlled lesions are smaller and more superficial due to shorter ablation duration and smaller amount of energy delivered to tissue due to the high peak electrode temperature with sudden rise in impedance prohibiting ablation (3). In contrast, irrigated lesions are deeper with peak tissue temperatures between 3.5 mm and 7.5 mm depths (3). (B) Schematic hypothesizing that nonirrigated ablation in the posterior left atrial wall would produce lesions mainly limited to the endocardium with less collateral esophageal injury than with irrigated lesions, which would produce maximal tissue temperatures (red dot) near the epicardial surface and possibly within esophageal tissue. LA = left atrium; RF = radiofrequency.