Coronary artery disease is a common heart disease, mainly due to myocardial ischemia caused by the narrowing of coronary vessels after coronary atherosclerosis. In serious cases, it can cause myocardial infarction. Epidemiological factors: The incidence rate used to be much lower than that of developed countries in Europe and America, but with the improvement of living standards in China, the incidence rate is gradually increasing. The age also tends to be younger. High-risk groups: Commonly seen in people with obesity, hypertension, hyperlipidemia and diabetes, also seen in people with stressful life and work. Clinical manifestations: intermittent precordial pain, sometimes radiating to the shoulder and left upper extremity. Some people present with toothache, tight throat, etc. If myocardial infarction occurs, the symptoms will be more severe. The precordial pain is not easily relieved and sometimes requires emergency PCI or coronary artery bypass surgery. Physical examination: Generally, the heart sound is only weak. If mitral valve insufficiency is combined, there will be a murmur of mitral valve insufficiency. If cardiac insufficiency is present, lower limb edema, chest tightness, and palpitations will also be present. Laboratory tests: elevated cardiac enzymes and sometimes elevated blood white blood cells. Special tests: ST segment abnormalities on ECG, coronary angiography is the gold standard for diagnosis. Coronary CTA can be used as a screening and is also diagnostic. Treatment There are drug treatment, interventional treatment and surgical treatment. Drug therapy: mainly some drugs to improve microcirculation, dilate coronary arteries, anti-platelet coagulation, lower lipid and lower blood pressure. Interventional therapy: Nowadays, it is increasingly used in clinical practice, with the characteristics of minimally invasive, rapid, and emergency treatment. Surgical procedures: coronary artery bypass grafting under extracorporeal circulation and non-extracorporeal circulation, now the success rate of the procedure can reach 98-99%. The grafts used are: internal mammary artery, radial artery, saphenous vein, etc. Post-operative precautions: Take long-term antihypertensive, lipid-lowering and anti-platelet coagulation drugs. Pay attention to regular diet, regular life, etc.