Circulation Journal Official Journal of the Japanese Circulation Society http://www. j-circ.or.jp and postoperative complications and requirements, have been evaluated as predictors of POAF; however, most of these predictors were not consistent among studies and only advanced age was a consistent predictor. 6 Recently, echocardiographic assessments have achieved much better prediction of POAF by measuring the left atrium-related values including the left atrial volume index (LAVI), LA strain and total atrial conduction time (TACT). Although there are several measurements of TACT, the time interval from the P-wave onset on the electrocardiogram (ECG) to the peak of the A' lateral wave on TDI (PA-TDI duration) provides a reliable estimation of TACT, and the PA-TDI duration has been shown to be significantly related to new-onset AF. 7,8 Our previous study revealed that the PA-TDI duration was predictive of AF in patients undergoing off-pump coronary artery bypass grafting (CABG). 9 trial fibrillation (AF) is a common complication after cardiac surgery, occurring in 10-65% of the patients. 1 Several studies have found adverse outcomes associated with postoperative AF (POAF), including increased risk of hospital stay, higher risk of stroke, permanent pacemaker implantation, and increased in-hospital and long-term mortality rates. 2 The incidence of POAF is higher with valvular surgery. 3 Obviously, in aortic valve (AV) surgery, the incidence of AF is related to these postoperative complications. 4 Moreover, Filardo et al reported that new-onset POAF was significantly associated with increased long-term risk of mortality in patients undergoing AV replacement (AVR) surgery. 5 These results indicate that POAF should be prevented and controlled postoperatively.In the past 2 decades, many clinical variables, including preoperative characteristics, comorbidities, intraoperative findings A