Patients with myocardial ischemia require cardiography to clarify the cause of myocardial ischemia. Myocardial ischemia is a disease caused by various factors such as cardiogenic factors or other diseases, usually with symptoms such as chest tightness, shortness of breath, palpitations, precordial discomfort accompanied by dyspnea, etc. It needs to be further clarified whether it is caused by cardiogenic diseases, and the gold standard for diagnosis is cardiography. If the patient’s condition does not allow cardiography, it is recommended to do 320-row or 630-row enhanced CT, and at the same time improve the cardiac ultrasound, cardiac enzymes monitoring, 18-lead electrocardiogram, dynamic electrocardiogram and other examinations, to clarify the origin of myocardial ischemia, and then carry out the treatment for the cause of the disease.