ECG manifestations of myocardial ischemia.

Exercise ECG is widely used for the diagnosis of ischemic heart disease. The most common ECG sign of myocardial ischemia is flat or down-sloping ST-segment depression of 1.0 mm or greater. This report draws attention to other much less common, but possibly equally important, ECG manifestations of myocardial ischemia. Serial ECGs obtained during the treadmill stress test of a 40-year-old man with angiographically proven coronary artery disease exhibited virtually all known ECG signs of ischemia, namely, ST-segment depression, ST-segment elevation and alternans, intraventricular conduction abnormalities, and U-wave inversion.