Abstract

The association between ambient circulating environments (CE) and ablation lesions has been largely underexplored.Viable bovine myocardium was placed in a saline bath in an ex vivo endocardial model. RF ablation was performed using 3 different ablation catheters: 3.5mm open irrigated (OI), 4 mm, and 8 mm. Variable flow rates of surrounding bath fluids were applied to simulate standard flow, high flow, and no flow. For in-vivo epicardial ablation, 24 rats underwent a single OI ablation and performed with circulating saline (30 ml/min; n=12), vs. those immersed in saline without circulation (n=12).High flow reduced ablation lesion volumes for all 3 catheters. In no flow endocardial CE, both 4 mm and OI catheters produced smaller lesions compared to standard flow. However, the 8 mm catheter produced the largest lesions in a no flow CE. Ablation performed in an in-vivo model with CE resulted in smaller lesions compared to ablation performed in a no-flow environment. No statistically significant differences in steam pops were found amongst the groups.A higher endocardial CE flow can decrease RF effectiveness. Cardiac tissue subjected to no endocardial CE flow may also limit RF for 4 mm catheters, but not for OI catheters; these findings may have implications for RF ablation safety and efficacy, especially, in the epicardial space without circulating fluid or in the endocardium under varying flow conditions. This article is protected by copyright. All rights reserved.

View details for DOI 10.1111/jce.15874

View details for PubMedID 36852908