Ability of Left Atrial Distensibility After Radiofrequency Catheter Ablation to Predict Recurrence of Atrial Fibrillation

This study sought to assess the left atrial (LA) functional recovery after radiofrequency catheter ablation (RFCA) for atrial fibrillation (AF) and to evaluate the determining factor of procedural success of RFCA, using a novel preload stress echocardiography. A total of 111 patients with AF were prospectively recruited. The echocardiographic parameters were obtained during the leg-positive pressure (LPP) maneuver, both at baseline and midterm after RFCA. As an index of LA distensibility, the LA expansion index was calculated as (LAV_max - LAV_min) × 100 / LAV_min. During a median follow-up period of 14.2 months, AF recurrence was observed in 23 patients (20.7%). In LA functional parameters at baseline, only the Δ LA expansion index was significantly larger in the success group (16 ± 11% vs 4 ± 9%, p <0.05). At midterm follow-up, the Δ LA expansion index significantly increased to 32 ± 19% (p <0.05), together with structural LA reverse remodeling only in the success group. Moreover, the Δ stroke volume index during the LPP stress test significantly increased only in the success group (from 2.3 ± 1.3 ml/m² to 3.1 ± 4.8 ml/m², p <0.05). In a multivariate analysis, left ventricular ejection fraction (hazard ratio 0.911, p <0.05) and baseline Δ LA expansion index (hazard ratio 0.827, p <0.001) were independent predictors of AF recurrence. In conclusion, the baseline Δ LA expansion index during LPP stress is a reliable marker for predicting procedural success after RFCA. Moreover, maintenance of sinus rhythm resulted in an improvement of the preload reserve after RFCA.