With the improvement of people’s living standard, the incidence of heart disease is increasing year by year. The common diseases of cardiac surgery include congenital heart disease, heart valve disease, coronary heart disease and aortic aneurysm. The following are introduced one by one I. Congenital heart disease Congenital heart disease is due to the development of the fetal heart in the process of interference, so that part of the development of halted or defective. Common causes include maternal nutritional disorders, vitamin deficiencies and metabolic diseases and maternal consumption of certain drugs or prolonged radiation exposure. Common congenital heart diseases include patent ductus arteriosus, atrial septal defect, ventricular septal defect, pulmonary stenosis and tetralogy of Fallot. Congenital heart disease is asymptomatic in mild cases, but in severe cases, there may be dyspnea, cyanosis, syncope and growth retardation after activity. Common congenital heart disease can be diagnosed by symptoms, auscultatory murmurs and cardiac ultrasound. The normal human heart has four chambers and four groups of heart valves, namely mitral valve, tricuspid valve, aortic valve and pulmonary valve. Its function is to enable the blood flow in the heart to maintain a one-way flow, maintaining the normal blood circulation of the body. However, rheumatism, infection and other causes can lead to valve stenosis or incomplete closure, resulting in abnormal heart hemodynamics, increasing the load on the heart, leading to cardiac insufficiency and even failure, and eventually leading to death. Heart valve disease is often manifested by post-activity panic, shortness of breath, cough, hemoptysis, inability to lie down, swelling of the lower limbs, and paroxysmal dyspnea at night. Patients with aortic stenosis or insufficiency of closure may also experience syncope and angina pectoris that resembles coronary artery disease. If combined with atrial fibrillation and thrombosis, symptoms of cerebral embolism “stroke” or limb embolism may also occur due to thrombus dislodgement. The most specific sign of a valve patient is a specific murmur on auscultation of the diseased valve area, and early access to an experienced physician for cardiac ultrasonography is the best way to make an early diagnosis. Surgical procedures are the fundamental treatment for heart valve disease. It is not possible to reverse valve disease with medication alone. The most widely used surgical procedures are valvuloplasty and valve replacement. Although valvuloplasty, or valve repair, is beneficial to patients (it saves money on prosthetic valves and eliminates the need for long-term postoperative anticoagulants), it requires a high level of surgeon involvement and carries a certain amount of risk for reoperation, which patients should consider carefully before surgery. The two main types of medical replacement valves available today are mechanical and biological valves. The former has the advantages of long service life (expected service life of 40–60 years) and relatively low price (about 4,000 yuan for domestic flaps and about 15,000 yuan for imported flaps), but its disadvantages are 1, the need to take anticoagulants for life after surgery, 2, improper administration can cause hemorrhage or embolism, 3, noise, 4, mechanical failure, 5, anticoagulants can cause hemorrhage during pregnancy, and 6, anticoagulants can cause possible fetal malformation. The biologic valve avoids these disadvantages, but it is more expensive and has a limited service life (only about 20 years), so it is more suitable for older patients or women who want to have children, and it does not require medication after surgery. Coronary heart disease Coronary heart disease is called coronary atherosclerotic heart disease, mainly due to the supply of blood to the heart of the coronary arteries because of atherosclerosis and other reasons, the narrowing of the lumen, resulting in insufficient blood supply to the heart muscle. In mild cases, angina pectoris can occur, and in severe cases, myocardial infarction or even sudden death can occur. The main clinical manifestations are chest pain or chest tightness, breath-holding, especially after activity or when emotionally excited, or ischemic necrosis clinically causing arrhythmia and heart failure, which is a common and frequent acquired heart disease in middle and old age. Coronary angiography is one of the most direct and reliable tests widely used in clinical practice, and is considered the “gold standard” for the diagnosis of coronary artery disease. The treatment of coronary artery disease mainly includes three aspects, namely, drug treatment, interventional treatment and surgery. The choice of treatment method is mainly based on the results of coronary angiography. Generally speaking, for patients with mild coronary artery lesions and luminal stenosis not exceeding 50%, drug therapy is the main treatment, which can relieve some symptoms of coronary artery disease, but cannot delay the progress of coronary atherosclerosis, so it is a kind of palliative treatment. For patients with more limited coronary artery lesions and stenosis of more than 50%, interventional therapy is an option, but the incidence of restenosis is relatively high. If the degree of coronary artery lesion is more severe and the number of involved vascular branches is more, then paracoronary artery bypass grafting should be chosen to restore the blood supply to the distal end of the coronary artery lesion, which can bring great improvement to the patient’s quality of life. IV. Aortic aneurysm Aortic aneurysm is an aneurysmal dilatation of the aortic vessel wall caused by various reasons, such as congenital malformation, inflammation, hypertension, atherosclerosis, trauma, etc. Aortic coarctation is caused by the rupture of the aortic intima. High-velocity blood flow rushes into the middle layer of the aortic wall through the rupture of the aortic intima, forming a new lumen in the middle layer that can rupture at any time, posing a great threat to life. The two symptoms, pain and compression, are often present. Ultrasound, computed tomography (CT) and magnetic resonance imaging (MRI) examinations help in the diagnosis. Surgical treatment is the only way. Surgical treatment of aortic aneurysms, including aneurysm removal with artificial or homologous vascular grafts, currently has a surgical mortality rate of less than 5%, but can exceed 25% in those who are too old and have heart, brain, kidney or other internal organ damage.