1.Coronary arteriography (CAG) is a technique to diagnose coronary artery disease, which is the “gold standard” for coronary artery disease. A special cardiac catheter is sent to the root of the aorta through the radial (femoral) artery, inserted into the left and right coronary artery orifices respectively, and a small amount of contrast is injected for rapid and continuous filming and photography to discover the site and degree of coronary artery stenosis, and coronary artery disease can be diagnosed when the degree of stenosis is greater than 50%. 2.Percutaneous transluminal coronary angioplasty (PTCA) When coronary angiography suggests that your coronary artery stenosis exceeds 75% of the lumen, and there is no contraindication to the premise, you can be treated by internal PTCA. This is a non-surgical procedure in which a specially designed cardiac catheter or balloon is sent through the radial (femoral) artery to the lesion, and the narrowed coronary artery is dilated by compression molding to relieve the stenosis and improve its blood supply to the heart muscle. 3.Percutaneous transluminal coronary artery stenting Based on PTCA, a stent made of special material is placed into the diseased coronary artery to support its wall in order to keep the blood flow in the lumen smoothly. 4.What you need to do before surgery (1) Pay attention to keep warm before surgery and reduce visits to prevent colds. (2) Prepare a commode and train to defecate and urinate in bed. (3) Eat light and easily digestible food on the operation day, such as noodles, ravioli, etc. Avoid flatulent foods such as soy milk, eggs and milk. (4) Empty urine before surgery. 5.How do you need to cooperate after surgery? (1) After the operation, we need to give you cardiac monitoring, please do not adjust the instrument by yourself. (2) Please drink about 800-1000ml of water within 2-4 hours after surgery to accelerate the metabolism of the contrast agent. (3) If you have a radial artery puncture, please elevate the limb on the operated side and reduce the activity. If you have a femoral artery puncture, you need to sandbag compression for 6 hours, brake the limb on the operated side for 12 hours, bed rest for 24 hours, ankle exercise 10 times/hour, effective coughing 10/hour, bed urination and defecation, avoid increasing abdominal pressure movements after the operation, such as pressing the puncture site when urinating or coughing to prevent bleeding. (4) Eat light and easily digestible food, avoid foods containing much sugar and easy to produce gas such as soy milk, milk and soy products, etc. You can resume normal diet 24 hours after surgery, with low salt, low fat and low cholesterol easy to digest food. (5) If you feel unwell, please inform the medical staff in time.