In my daily clinical practice, I often encounter this situation: doctor, I have cardiac ischemia, I have angina pectoris, my electrogram says T wave change, myocardial ischemia, my electrocardiogram has old myocardial infarction …… and so on and so forth many such questions. In fact, in this, many patients are not coronary heart disease, not myocardial infarction, which is the final conclusion we reached after coronary angiography. Coronary angiography is still the “gold standard” for the diagnosis of coronary artery disease. My teacher, the famous German-Chinese cardiologist Dr. Yu Jiangtao, said, “Coronary angiography is the mirror of evil”. A true coronary artery disease requires a coronary angiogram, a false coronary artery disease requires a coronary artery angiogram to rule out, and a suspicious coronary artery disease requires a coronary artery angiogram to clarify. Therefore, for most patients, if you have symptoms of angina pectoris and myocardial ischemia, especially if they are new, have frequent attacks, or are poorly treated with medication, your cardiologist recommends that you have a coronary angiogram, at which point you must not hesitate, because coronary angiogram is a demonoscope.