Angina pectoris is a series of symptoms due to myocardial ischemia, which is characterized by cramping pain and tightness at the back of the sternum and the back of the body, radiating to the left shoulder, the left arm, the little finger and the ring finger. It is usually due to coronary artery stenosis that leads to myocardial ischemia and hypoxia, resulting in the symptoms of angina pectoris. Once back pain occurs, an electrocardiogram (ECG) should be given in a timely manner. The ECG can clearly show that there is ST-segment depression in each lead, or T-wave inversion or hyperacuity, and through these basic tests, it can be clarified whether or not there are symptoms of myocardial ischemia. Then cardiac ultrasound, coronary CTA and coronary angiography can be done to clarify the degree of coronary lumen narrowing, and through these tests, the next plan can be formulated so that the symptoms of myocardial ischemia can be relieved.