The ECG changes of variant angina are as follows: 1. When variant angina does not attack, the ECG can be normal or have mild ST-segment downward shift, T-wave depression or light inversion; 2. When angina attacks, there will be obvious ST-segment elevation, ST-segment is bow-back elevation, ST-T fusion, forming a one-way curve, this situation is more dangerous; 3. The symptoms of chest pain, variant angina belongs to the unstable angina, after the attack ST segment can recover, ST segment to return to the baseline level or return to the level of the electrocardiogram before the attack. The pathogenesis of variant angina is mainly coronary spasm, regardless of whether there is atherosclerosis of the coronary arteries, there will be episodes of spasm of the coronary arteries. The duration of this ST-segment elevation is related to the duration of the patient’s symptoms and the degree of the patient’s symptoms. In addition, variant angina is not triggered by exertion or emotional stress and is often associated with arrhythmias or syncope.