Value of atrial electromechanical conduction time predicating the recurrence of atrial fibrillation after successful radio frequency catheter ablation

Abstract

Objective The aim of this study was to evaluate the value of atrial conduction time, measured by tissue Doppler echocardiography, for predicting atrial fibrillation (AF) recurrence after successful radio frequency catheter ablation (RFCA) . Methods One hundred and forty-four paroxysmal AF (PAF) patients were enrolled in the study, who accepted RFCA operation in Renmin Hospital of Wuhan University from July 2013 to October 2015. Eighty-two control subjects were also collected in the study and all subjects underwent echocardiographic examination under sinus rhythm. Left atrial volume index and left ventricular systolic and diastolic function indicators were measured by conventional echocardiography. Atrial electromechanical delay time (EMD, measured from the onset of P wave to the onset of the beginning of a’wave) were detected by tissue Doppler image. EMD was calculated on lateral mitral annuli, septal mitral annuli and right ventricular tricuspid annuli. The differences between these intervals were defined as interatrial electromechanical conduction time (IACT) , intra-right atrial electromechanical conduction time (IRCT) and intra-left atrial electromechanical conduction time (ILCT) . Patients were divided into two groups AF recurrence (AFR) group and sinus rhythm recurrence (SRR) group during 12 months of follow-up. Results IACT、ILCT and IRCT were significantly higher in AFR group than in SRR group[ (20.92±13.76) ms vs. (13.98±10.01) ms, P=0.004; (21.58±12.57) ms vs. (15.84±11.41) ms, P=0.015; (16.27±10.79) ms vs. (12.31±10.10) ms, P=0.044) . Left atrial diameter (LAD) , right atrial diameter (RAD) , left atrial end-diastolic volume (LAEDV) , and left atrial end-systolic volume (LAEDV) were also significantly higher in AFR group than in SRR group (all P<0.05) . While A and a′ were significantly lower in PAF group than in control group (all P<0.05) . IACT and ILCT were significantly higher in AFR group than in SRR group[ (26.86±20.67) ms vs. (19.45±11.04) ms, P=0.047; (37.64±9.62) ms vs. (17.63±9.78) ms, P=0.000 1) . ILCT was an independent predictor of the AF recurrence after successful RFCA, in receiver operating characteristic curve analysis with AUC 0.931. When ILCT≥24.5 ms the sensitivity and specificity were 0.929 and 0.789, respectively. Conclusion Atrial electromechanical conduction time detected by tissue Doppler echocardiography was significantly higher in PAF patients. ILCT is a useful predictor for atrial fibrillation recurrence independently. Key words: Atrial fibrillation; Recurrence; Atrium; Electromechanical conduction