1, the role of echocardiography in the diagnosis of valve disease Echocardiography can clarify the size of each heart chamber, blood flow rate, the opening area of each valve, opening and closing conditions, and the presence of valve calcification, redundancy and other conditions, especially for valve regurgitation is very sensitive. Echocardiography can clarify the presence or absence of pericardial effusion and its amount before and after cardiac surgery, and is very effective in identifying the quality of prosthetic valve activity and the presence or absence of stuck valves after valve surgery, and can be used intraoperatively to determine the effect of surgery by transesophageal ultrasound technology, to clarify the presence or absence of perivalvular leakage and the effect of valve formation, and to reoperate for further correction if there are problems. Therefore, echocardiography is currently the main diagnostic tool in valve surgery. Moreover, this method is non-invasive and can be repeatedly examined. 2.The role of chest radiography in the diagnosis of valve disease Chest radiography can not only observe the size of the heart, but also clarify how much and how thick the lung texture is, and which heart cavity changes are the main ones, and can also understand the condition of the pulmonary circulation and whether there is obvious aortic calcification, so as to evaluate the extent of the lesion. Postoperative chest radiography can determine the presence or absence of pericardial effusion, the condition of the lungs and compare the changes in the heart before and after surgery. The image of the heart with valvular lesions is often enlarged, such as a barium swallow examination of the esophagus that reveals compression of the esophagus, indicating an enlarged left atrium and a flask-shaped change in the heart image appearance when the amount of pericardial effusion is large. 3, the role of electrocardiogram in the diagnosis of valvular disease electrocardiogram is the most used examination means in cardiac surgery, which can understand the changes of heart rate and heart rhythm of patients, and for various arrhythmias, drugs can be given according to the changes of electrocardiogram, and the effect of drugs after observation. It is also possible to understand the extent of the lesion and its progress according to the changes in the ECG, and to evaluate the effect of cardiac surgery according to the ECG. 4, the role of coronary angiography in the diagnosis of valve disease For patients who are over 50 years old or have symptoms of coronary artery stenosis, coronary angiography is routinely performed before surgery, and according to the results, it is decided whether to perform coronary artery bypass surgery at the same time as valve surgery. This is because the age of 50 is a high incidence of coronary artery disease. If severe coronary artery stenosis is combined with coronary artery bypass surgery but not performed, the myocardial ischemia itself combined with the blow of the surgery may prevent the heart from beating again after the surgery, or the low heart displacement syndrome may occur, which is difficult to correct. After surgery, echocardiography, electrocardiogram and chest X-ray are the means to evaluate the effect of surgery. The evaluation of valve surgery using transesophageal ultrasound, especially intraoperatively, has been achieved with good results in units that have the means to do so.