Clinical findings of myocardial ischemic changes by ECG evaluation are combined with vascular examination to clarify the etiology. When ischemic changes are found on the ECG, further look for stenosis in the blood vessels supplying the heart. If there is a true ischemic deficiency in blood supply, the combination is needed to diagnose the myocardial ischemic changes together. For patients with true ischemic changes, we should start with atherosclerosis and stenosis, control atherosclerosis, such as taking statins, and improve ischemia by taking vasodilators, such as nitrates. Those with severe stenosis can consider coronary intervention to improve the state of blood supply and oxygen supply to make ischemic changes. Beta-blockers can also be taken to slow down the heart rate and reduce sympathetic excitation to increase myocardial blood supply. If there is no real myocardial ischemia but only ST-T changes on the ECG, it is necessary to further investigate whether there is microangiopathy, sympathetic overstimulation leading to ST-T changes, or hypertension causing myocardial hypertrophy, thus secondary to ST-T changes.