It is a type of heart disease in which myocardial ischemia and hypoxia (angina) or myocardial necrosis (myocardial infarction) is caused by narrowing or blockage of the coronary arteries. Coronary heart disease is also known as coronary atherosclerotic heart disease. The narrowing of the coronary arteries is mostly caused by the accumulation of fatty substances along the inner wall of the blood vessels, a process called atherosclerosis. When atherosclerosis develops to a certain extent, the narrowing of coronary arteries gradually increases, limiting the blood flow to the heart muscle. When the heart is not supplied with enough oxygen, chest discomfort, or angina, occurs. The manifestation of angina varies from person to person. Most people describe it as “chest pressure”, “stuffy feeling”, “suffocating feeling”, and some patients feel it radiating to the left shoulder, back, neck and throat, which is relieved by resting or taking nitroglycerin. Myocardial infarction is another manifestation of coronary artery disease, and its chest pain is persistent and severe, and rest or nitroglycerin is ineffective. In myocardial infarction, the coronary artery is completely blocked and the part of the heart muscle is necrotic because there is no blood supply. Most of them are caused by the formation of blood clots in the narrowed part, atheromatous plaque rupture or vascular spasm. Yao Yucai, Department of Cardiology, Shandong Qianfo Mountain Hospital