Clinical Utility of Atrial Electromechanical Conduction Time Measured with Speckle Tracking Echocardiography after Catheter Ablation in Patients with Atrial Fibrillation: A Validation Study with Electroanatomical Mapping

Purpose: Our recent report demonstrated that atrial electromechanical conduction time (EMT-epsilon) measured with speckle tracking echocardiography could predict cardiac events in patients with pathological left ventricular hypertrophy. This study aimed to validate EMT-epsilon by comparison with electroanatomical mapping and to investigate the clinical utility of EMT-epsilon in patients with atrial fibrillation (AF) undergoing catheter ablation. Methods: Forty-six patients with preserved LV ejection fraction (LVEF >= 50%) undergoing pulmonary vein isolation (PVI) for AF were studied. Atrial electrical conduction delay was determined by measuring atrial electrical activation time (EAT) using three-dimensional electroanatomical mapping just after PVI. Echocardiographic parameters were acquired within 24 hours and at 6 months after PVI. The study also included 10 control subjects. Results: AF patients had a larger left atrial (LA) volume index (LAVI) and more prolonged EMT-epsilon compared with control subjects. According to the validation study, EAT was closely related to EMT-epsilon and a', and this association was independent of LAVI and the presence of persistent AF (EMT-epsilon: R-2 = 0.342, P < 0.0001, a': R-2 = 0.337, P < 0.0001). At 6 months after PVI, LAVI and EMT-epsilon were significantly improved. During continued follow-up beyond 6 months (total follow-up, 26 +/- 12 months), the EMT-epsilon shortening at 6 months after PVI was significantly greater in AF-free patients than patients with AF recurrence. Conclusions: This study suggested that the EMT-epsilon could be a useful echocardiographic marker of LA electromechanical abnormalities in patients with AF.