Atrial electromechanical interval can identify patients with paroxysmal atrial fibrillation and is associated with CHADS₂ score and peak velocity of left atrial appendage

Introduction: It is difficult to discriminate patients with and without paroxysmal atrial fibrillation (PAF). The atrial electromechanical interval determined by the transthoracic echocardiogram is demonstrated to be a predictor of new onset AF. The aim of our study was to investigate whether the electromechanical interval is a useful parameter to identify patients with PAF. Methods and Results: A total of 297 patients (PAF group = 103; control group = 194) with mean age of 59.4 ± 12.4 years were enrolled. The electromechanical interval (PA-PDI) defined as the time interval from the initiation of the P-wave deflection to the peak of the mitral inflow A wave on the pulse-wave Doppler imaging was measured for every patient. Patients with PAF had significantly longer PA-PDI intervals compared with that of patients without it (152.7 ± 13.8 ms vs 133.4 ± 16.8 ms). The area under ROC curve based on the PA-PDI interval to diagnose PAF was 0.803 (95% confidence interval = 0.755-0.851, P < 0.001). At the cut-off value of 142 ms, the sensitivity and specificity in identifying PAF were 77.7% and 80.1%, respectively. In the PAF group, the PA-PDI interval was closely associated with the CHADS₂ score and inversely related with the peak velocity of left atrial appendage. Conclusions: The PA-PDI interval may be a useful parameter to identify patients with PAF. Further studies are necessary to evaluate the usefulness of PA-PDI intervals in diagnosing PAF in addition to the current methods and tools.