The preoperative electrocardiogram as an indicator of risk in major noncardiac surgery.

In this series of 198 patients studied prospectively before major noncardiac surgery, we previously reported that an abnormal preoperative electrocardiogram was a statistically significant independent predictor of an increased risk of postoperative complications, i.e., death, myocardial infarction, or myocardial ischemia. We therefore carried out a detailed analysis of the preoperative electrocardiographic (ECG) findings using Minnesota code criteria. Both ST-T abnormalities and intraventricular conduction delays showed a statistical trend toward a higher frequency in patients with a complicated vs. an uncomplicated postoperative course (82% vs. 59% and 24% vs. 7%, respectively). Although only a minority of patients with either ECG finding actually developed a complication (22% and 40% respectively), the preoperative ECG appears to be a useful screening method, with ST-T abnormalities and intraventricular conduction delays identifying patients at increased risk for postoperative complications.