Coronary artery disease is an abbreviation for atherosclerotic coronary heart disease. Coronary arteries are the arterial vessels that supply blood to the heart muscle. After coronary artery atherosclerosis, its lumen gradually narrows, resulting in insufficient blood supply to the heart muscle, causing angina pectoris, which starts after exertion, such as chest tightness, shortness of breath and chest pain called exertional angina. It is relieved after rest. Further aggravation of the disease can also develop in the resting state is called unstable angina. High-risk factors that tend to lead to coronary heart disease are hypertension, diabetes, hyperlipidemia, genetic factors, obesity, excessive meat, and so on, which should be actively prevented. We should try to avoid the occurrence of coronary heart disease. For diagnosis, there is enhanced CT examination, which is suitable for universal examination, easy to do but not very accurate. Coronary angiography is the most accurate test, which requires hospitalization in the cardiac catheterization laboratory. The doctor inserts a catheter directly into the opening of the coronary artery, injects a special contrast agent and then instantly records the video to observe the distribution of the contrast agent in the coronary vessels, thus checking where and to what extent the vessels are narrowed. If the stenosis is limited, a stent can be placed. If the stenosis is severe, coronary artery bypass grafting is often required. Coronary artery bypass grafting is a procedure in which one’s own blood vessels, such as the internal mammary artery and saphenous vein, are used as bridge vessels to divert blood to the distal part of the stenosis to improve ischemia in the heart muscle.