Abstract 2345: Radiofrequency Ablation of the Cavotricuspid Isthmus Independently Mitigates the Arrhythmogenicity of Remote Ectopic Atrial Beats

Background: Radiofrequency ablation (RFA) of isthmus-dependent atrial flutter (AFL) in patients with AFL and atrial fibrillation (AF) has been shown to decrease the future AF burden. The purpose of this study was to test the hypothesis that RFA of the cavotricuspid isthmus (CTI) renders ectopic atrial beats (EABs) less arrhythmogenic without effecting the frequency of EABs. Methods: The study comprised patients who had drug-refractory paroxysmal AFL and AF without a transition of either arrhythmia to the other. The frequency of EABs and percentage of AF episodes per EAB were assessed before, during, and after CTI ablation. Atrial effective refractory periods (AERPs) were measured before and after RFA. Results: Twenty-three patients were included (mean age, 56.3±7.4 y). During electrophysiology studies, the average number of EABs per minute was 4.8±3.8 before ablation and 4.5±1.8 after ablation (P=NS). Before ablation of the CTI, 35.2±10.7% of the EABs led to bursts of AF lasting at least 5 seconds. After ...