Abstract 20102: Time-to-Effect Based Cryoballoon Dosing to Achieve Permanent Pulmonary Vein Isolation -The First Chronic Study in Canine Model

Background: Cryoballoon ablation (CB) is an effective treatment for Paroxysmal Atrial Fibrillation (PAF). Current time-based dosing may be inadequate to characterize the cryo-thermal energy transfer and collateral injury pattern. Physiologic end-point such as time to effect (TTE) (i.e. acute loss of pulmonary vein (PV) signals) can be monitored during ablation but correlation to long-term pulmonary vein isolation (PVI) has not been established. This study evaluated acute and chronic PVI results and collateral tissue damage with a goal of determining a TTE dosing regimen to optimize CB efficacy and safety. Methods: 30 PVs (left and right superior branches) from 15 healthy mongrel dogs (avg. 30.5kg) were randomized into 5 dosing groups: 1. TTE+60 seconds; 2. TTE+90 seconds; 3. TTE+120seconds; 4. TTE+150 seconds; 5. 2x180 seconds. Ablations were performed with a 23mm Arctic Front Advance® CB and TTE measured by The Achieve™ Mapping Catheter. Esophageal temperature was monitored using the Circa S-CathTM and e...