Procedural details
Procedural methods and approaches used for left atrial PVI ablations in this site reflect those used by most hospitals performing atrial ablations in the US. All patients in the study were put under general anesthesia. Wide area circumferential PVI, additional posterior wall isolation, mitral isthmus lines, and cavotricuspid isthmus lines were employed depending on patient need or physician preference. Patients were given heparin with a targeted active clotting time >300 seconds. Three-dimensional geometry and Electro-anatomical mapping were obtained using the CARTO mapping system (Biosense Webster, Inc., Diamond Bar, CA). All operators used irrigated contact force sensing catheters (ThermoCool SmartTouch Surround Flow (STSF) catheter, Biosense Webster, Inc., Diamond Bar, CA). Power settings utilized a high-power short duration (HPSD) approach, using 40 W to 50 W power. A Visitag Surpoint® ablation index (Biosense Webster, Inc.) was targeted to 350 to 400 units on the posterior wall, and 450 to 550 units on the anterior wall, ridge and septum. Throughout the duration of this analysis, there were no changes in equipment usage or ablative technique, other than the adoption of proactive esophageal cooling, and the abandonment of LET monitoring and/or esophageal deviation.