Abstract 20645: Ambient Circulation Surrounding an Ablation Catheter Tip Will Affect Delivery of Radiofrequency Current and Ablation Lesion Characteristics

Introduction: The circulating environment (CE) surrounding an ablation catheter electrode may affect radiofrequency (RF) current. A higher flow CE around a catheter tip may impact RF of targeted cardiac tissue. In addition, limited data exist for the epicardium, where there is no CE, which may affect epicardial ablation. We sought to evaluate whether different circulating environments affect RF ablation lesion characteristics. Methods: Viable bovine myocardium was placed in a saline bath in an ex vivo model. Prior to performing ablation experiments, the flow of the circulating bath surrounding a catheter tip was altered with variable speeds of 70 meters (m)/min (high flow), 30 m/min (standard flow), and 0 m/min (no flow). RF was applied for 60 seconds with constant force using a standard 4 mm tip catheter at 50W, open irrigated (OI) 3.5 mm tip catheter at 50W, and 8 mm tip catheter at 70W. Results: High flow surrounding the catheter tip reduced ablation lesion volumes, compared to standard flow, for all 3...