Purpose
Our recent report demonstrated that atrial electromechanical conduction time (EMT‐ε) measured with speckle tracking echocardiography could predict cardiac events in patients with pathological left ventricular hypertrophy. This study aimed to validate EMT‐ε by comparison with electroanatomical mapping and to investigate the clinical utility of EMT‐ε 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‐ε compared with control subjects. According to the validation study, EAT was closely related to EMT‐ε and a′, and this association was independent of LAVI and the presence of persistent AF (EMT‐ε: R2 = 0.342, P < 0.0001, a′: R2 = 0.337, P < 0.0001). At 6 months after PVI, LAVI and EMT‐ε were significantly improved. During continued follow‐up beyond 6 months (total follow‐up, 26 ± 12 months), the EMT‐ε 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‐ε could be a useful echocardiographic marker of LA electromechanical abnormalities in patients with AF.