AIM  To explore the predictive value of QRS interval shortening before and after cardiac resynchronization therapy in patients with (CRT) to CRT responsiveness.

  METHODS  From February 2012 to September 2019, 70 patients with heart failure who were successfully implanted with CRT were admitted to the heart center of our hospital. According to the improvement of left ventricular end-systolic volume ≥ 15% six months after CRT compared with that before operation, the patients were divided into reactive group and non-responsive group. The difference of clinical data between the two groups was compared. Binary logistic regression was used to analyze the predictive value of QRSd responsiveness to CRT, and the best cutoff value for predicting CRT responsiveness was judged by the receiver's working characteristic curve (ROC).

  RESULTS  Among the patients with chronic heart failure who were successfully implanted into CRT, there were 53 patients in response group and 17 patients in non-response group, and most of them were males. There were significant differences in left bundle branch block (LBBB) and left ventricular ejection fraction (△LVEF)、mitral regurgitation velocity (△MR)、△QRSd between the two groups before and after operation. Binary logistic regression analysis showed that △QRSd and△ LVEF were independent predictors of responsiveness in patients with CRT (OR=1.065, 95%CI: 1.012-1.122, P=0.017, OR=1.123, 95%CI: 1.010-1.248, P=0.032). The area under the ROC curve of QRS shortening value is 0.762(95%CI: 0.638-0.887), the maximum Jordan index is 0.402, the best cutoff point is 17 ms, the sensitivity is 0.755, and the specificity is 0.647.

  CONCLUSION  The shortening of QRS has a certain predictive value for the responsiveness of patients with CRT.