Posterior Left Atrial Volume Ratio Calculated by Multi-Detector Computed Tomography May Predict Short Term Success in Catheter Ablation of Atrial Fibrillation

Abstract

Background: Total left atrial volume (LAV) is one of important predictors in ablation success of atrial fibrillation (AF). As left atrial remodeling advances, atrial volume distribution may be changed. Sometimes left anterior, sometimes left posterior volume increases. Methods: We evaluated consecutive 40 patients. LAV was measured with Aquarius workstation. Anterior and posterior atriums were separated by plane made of pulmonary vein ostiums. Results: Paroxysmal (n=18) and non-paroxysmal (n=22) AF patients were enrolled. 19 patients had been treated with amiodarone. Left atrial diameter (LAD) was 39.0±4.5 mm. 23 patients were treated with antral isolation. 17 patients were treated with antral isolation and additional linear ablation. LAV was 129.6±23.6 cc. Posterior LAV was 32.3±7.0 cc (12.6±13.3%). Total and posterior LAV were not different between short term success (n=15) and fail (n=25) patients. However, ratio of posterior LAV and total LAV was significantly higher in short term success patients (21.8±13.1% vs. 8.4±11.4%, p=0.013). This ratio was independent of AF duration, hs-CRP, LAD and total LAV to predict short term success (p=0.032). When posterior LAV ratio is greater than 24.9%, prediction specificity was 93.7% and sensitivity was 66.7%. Conclusion: Posterior left atrial volume estimated by multi-detector computed tomography may be useful to identify patients in whom short term success can be achieved in AF ablation. This volume distribution difference seems to be valuable to study the relation with left atrial remodeling.