Electrocardiogram, cardiac radiograph and echocardiogram are three basic tests for congenital heart disease (CHD) that are non-invasive and can meet the diagnostic and therapeutic requirements for most simple and some complex precardiac diseases. However, there are some congenital diseases that require further cardiac catheterization and/or cardiovascular imaging in addition to the above tests to fully assess the anatomy and hemodynamics of the heart and to provide a basis for the development of a treatment plan. What are the specific conditions that require cardiac catheterization and/or cardiovascular angiography? 1, shunt preconditioning combined with severe pulmonary hypertension In cases of shunt preconditioning such as atrial septal defect, ventricular septal defect, patent ductus arteriosus, high-pressure right ventricular double outlet and transposition of the great arteries, if combined with severe pulmonary hypertension, and when the above three basic examinations and clinical conditions cannot determine whether there is an indication for surgery, cardiac catheterization is needed to evaluate pulmonary vascular resistance, and selective pulmonary angiography is done at the same time Observation of pulmonary artery morphology to assist in judging the condition is currently the ‘gold standard’ for effective preoperative determination of pulmonary hypertension associated with precardiac disease. 2, combined with pulmonary artery stenosis or dysplasia of precordial disease Echocardiography can only observe the proximal segments of the main pulmonary artery and the right and left pulmonary arteries, and it is difficult to accurately display the distal segments of the pulmonary arteries, the branching situation and whether there is the formation of body-pulmonary collateral vessels. Therefore, in the case of precordial diseases such as pulmonary artery branch stenosis, tetralogy of Fallot, pulmonary atresia, right ventricular double outlet and transposition of the great arteries in combination with pulmonary stenosis, imaging is often required to accurately assess the condition of the pulmonary arteries. If these precardiac diseases are combined with the formation of body-pulmonary collateral vessels, it is also necessary to improve interventional techniques to embolize large body-pulmonary collateral branches before performing radical surgery to facilitate intraoperative operations and reduce postoperative complications. 3. Precardiac diseases with complex cardiac malformations For some complex cardiac malformations, such as crossed hearts and abnormal vena cava connections, if they cannot be accurately evaluated by echocardiography or CT examination, they can also be diagnosed by cardiovascular angiography for diagnosis. 4, need to assess the hemodynamic situation Such as after single ventricle bidirectional Glenn surgery, the proposed total vena cava-pulmonary artery connection, cardiac catheterization and angiography should be done before surgery to accurately assess the development of pulmonary artery, pulmonary artery pressure, pulmonary vascular resistance, single ventricle function, the presence of large body-pulmonary collateral, etc., in order to decide whether there is an indication for surgery and to develop an appropriate surgical approach.