Left Atrial Electromechanical Conduction Time Can Predict Six-Month Maintenance of Sinus Rhythm After Electrical Cardioversion in Persistent Atrial Fibrillation by Doppler Tissue Echocardiography

Abstract

Background: The purpose of this study was to determine whether atrial electromechanical conduction time (EMT) measured by echocardiography can predict 6-month maintenance of sinus rhythm (SR) after electrical cardioversion in patients with atrial fibrillation (AF). Methods: Fifty-three patients with persistent AF (>1 month) who had successful cardioversion and 30 controls with SR were prospectively enrolled. SR maintenance was assessed during 6-month follow-up. EMT was measured as the time interval from the onset of the P wave on electrocardiography to the peak of the late diastolic wave from the septal and lateral mitral annulus (EMT-S and EMT-L, respectively) and the lateral tricuspid annulus (EMT-T) on tissue Doppler echocardiography. Results: Compared with controls, left atrial (LA) volume index, P-wave duration, and EMT were significantly larger in patients with AF (all P values < .001). In patients with AF, the duration of AF (P = .71) and P-wave duration (P = .24) were not different between the SR maintenance group (n = 23) and the AF recurrence group (n = 30), and there was a trend toward increased LA volume index in the AF recurrence group (47.0 +/- 12.4 vs 45.3 +/- 12.6 mL/ m 2, P = .07). EMT-S and EMT-L were significantly larger in the AF recurrence group (131.4 +/- 20.9 vs 116.3 +/- 15.5 ms, P = .005, and 152.2 +/- 15.7 vs 128.9 +/- 13.8 ms, P <.001, respectively), but not EMT-T. EMT-S and EMT-L were related to LA volume index (r = .36, P = .008, and r = .33, P = .02, respectively). On multivariate logistic regression analysis, only EMT-L was an independent predictor of identifying patients who remained in SR (P <.001), and the sensitivity and specificity for the prediction of 6-month maintenance of restored SR were 82.6% and 83.3% using a cutoff value of EMT-L <= 138.0 ms (odds ratio, 0.862; 95% confidence interval, 0.788-0.942; P = .001). Conclusion: LA EMT was significantly prolonged in patients with recurring AF, indicating significantly depressed atrial conduction in enlarged LA, and can predict 6-month maintenance of SR after electrical cardioversion. (J Am Soc Echocardiogr 201023:309-14.)