Abstract 17452: Inter-atrial Conduction Time Can Predict New-onset Atrial Fibrillation After Radiofrequency Ablation of Isolated, Typical Atrial Flutter

Abstract

Introduction: Previous studies showed inter-atrial conduction delay (IACT) is an important electrophysiological factor predicting atrial fibrillation (AF) after successful atrial flutter (AFL) ablation. To the best of our knowledge, there has no previous study regarding the prognostic value of IACT as a predictor of new-onset AF after AFL ablation without AF history. Hypothesis: The purpose of this study was to determine the incidence and predictors of new-onset AF after Radiofrequency ablation (RFA) of isolated AFL in a retrospective cohort study. Methods: This study included consecutive patients who underwent successful RFA of isolated, typical AFL from 2004 to 2012. Patients with any history of AF prior to AFL ablation were excluded. IACT was defined as the interval from the onset of P-wave in 12-lead electrocardiogram to atrial intracardiac electrogram at the distal coronary sinus catheter. Results: Eighty patients were included in this study. During a mean follow-up 3.4±2.6 years after successful AFL ablation, 22 patients (27.5%) developed new-onset AF. A Cox regression multivariate analysis demonstrated that IACT was the independent predictor of new-onset AF after AFL ablation (odds ratio: 13.3; 95% confidence interval: 1.36-152.5; p=0.0255). IACT was accurate in predicting new-onset AF (AUC=0.70). The optimal cut-off point of IACT for predicting new-onset AF was ≧120ms, with a sensitivity of 0.476 and a specificity of 0.898. Kaplan-Meier curves showed that new-onset AF after AFL ablation was significantly higher in the patients with IACT ≧120ms compared to the patients with IACT< 120ms (p=0.0016). Conclusions: IACT is an independent risk factor for new-onset AF after AFL ablation without a history of AF.