Electrocardiographic changes after coronary artery surgery.

The electrocardiographic changes early after uncomplicated coronary artery bypass with complete revascularization were examined preoperatively and on the 1st and 3rd postoperative days in 53 patients. Heart rate, PR index, corrected PR interval, corrected P dispersion, corrected duration of QRS complex, corrected QT dispersion, corrected QT interval, rhythm, QRS axis, ST-segment changes, and blocks were determined. Changes in new parameters obtained by different combinations of R, S, and T waves were also studied. On the 1st postoperative day, atrial fibrillation was significantly less prevalent, right bundle branch block increased significantly, and QRS axis was significantly more positive but returned to baseline on the 3rd postoperative day. Postoperative heart rate and PR index were significantly higher than preoperative values. In the postoperative period, corrected PR interval was significantly lower, corrected QRS complex duration was significantly shorter, corrected QT interval was significantly longer, and corrected QT dispersion showed a significant increase on the 1st postoperative day. This study defines electrocardiographic changes in uncomplicated patients with complete revascularization. Any deviations from these findings may alert us to the need for further evaluation of an undesired event.