Frontal planar QRS/T angle can be a prognostic factor in the early postoperative period of patients undergoing coronary bypass surgery

Abstract

Background: Wide QRS/T angle reflects the ventricular repolarization heterogeneity and has been found in association with cardiac morbidity and mortality in various study populations. However, literature data about the availability of QRS/T angle in patients undergoing cardiac surgery has not yet been available. Methods: A total of 157 patients who underwent isolated coronary artery bypass surgery were included in this study. A preoperative 12-lead ECG was obtained one day before surgical procedure. The absolute difference between the frontal QRS wave axes and T-wave axes was defined as frontal planar QRS/T angle. Afterwards, patients were divided into two groups according to their frontal planar QRS/T angle (the cut-off value as 90°). Results: Group 1 consisted of 109 patients with frontal planar QRS/T angle of >90, and the remaining 48 patients with frontal planar QRS/T angle 90 were placed into group 2. Mean EuroSCORE was much higher in group 2. There were significant differences for positive inotropic agent usage (27.5% for group 1 versus 58.3% for group 2, P >.001) and the prevalence of postoperative atrial fibrillation (11.9% for group 1 versus 31.2% for group 2, P =.004) between the two groups. In multivariate logistic regression analysis, used to determine the independent predictors of positive inotropic usage in the early postoperative period, only frontal planar QRS/T angle (OR: 0.989, 95% CI: 0.981-0.997, P =.008) and EuroSCORE (OR: 0.792, 95% CI: 0.646-0.971, P =.025) were found to be statistically significant. Conclusion: We found that frontal planar QRS/T angle might be an important preoperative parameter in predicting the need for inotropic drugs in the early postoperative period following coronary artery bypass surgery.