The ECG manifestations of exertional angina are as follows: 1. The ECG at rest, about 50% of patients have normal ECG or only slight ST changes, and patients who have suffered from old myocardial infarction will also have corresponding ECG changes of old myocardial infarction; 2. The ECG during the onset of angina after activity, including ST changes, in the R wave-dominated leads, the ST segment is ischemic downshifted depression; prone to T-wave changes, with T-wave hyperacute or T-wave hypotonic, bidirectional, or even inverted in leads dominated by R waves, accompanied by U-wave inversion. If there is already ST-segment depression or T-wave depression, the ECG changes will be more obvious during an exertional angina attack, but the changes are only temporary and can return to the pre-attack state when the angina is relieved after rest.