Improvement of Atrial and Ventricular Remodeling with Low Atrial Fibrillation Burden after Hybrid Ablation of Persistent Atrial Fibrillation

BACKGROUND: An endoscopic transdiaphragmatic epicardial radiofrequency ablation procedure combined with percutaneous endocardial radiofrequency ablation--a hybrid procedure--is a potentially curative treatment option for patients with persistent atrial fibrillation (AF). Long-term effects of arrhythmia elimination on atrial and ventricular remodeling are not completely understood. Therefore, the aim of our study was to quantify echocardiographic structural and functional changes of the left atrium (LA) and left ventricle (LV) following a hybrid procedure. METHODS AND RESULTS: Thirty-seven consecutive patients with symptomatic drug refractory persistent AF underwent a hybrid procedure to achieve complete pulmonary vein and LA posterior wall electrical isolation. AF burden was measured using an insertable electrocardiographic (ECG) monitor. Patients were divided into responders to ablation and nonresponders according to postoperative AF burden at 12-month follow-up (responder < 0.5% vs nonresponder ≥ 0.5%). Median AF burden was 0.32 (0.04-27.5)% for all patients. In responders (19/37 patients), significant echocardiographic reduction of LA volume index from 47 to 41 mL/m(2) (P < 0.05) and improvement of LA function parameters (LA stiffness from 73.3 to 41.3 [P < 0.05], LA emptying fraction from 21% to 45% [P < 0.05], LA global longitudinal strain from 11.2% to 18.8% [P < 0.5]) was documented. In addition, LV systolic function significantly improved in comparison with nonresponders. CONCLUSION: Hybrid ablation of persistent AF achieved stable sinus rhythm in a significant proportion of patients, as evidenced by continuous ECG monitoring, resulting in important LA and LV reverse remodeling after 12 months.