1. Transthoracic ultrasound monitoring commonly used views are: 1. Four-chamber cardiac view: to measure the size of the atrial septal defect, the length and thickness of the atrial ring stump tissue, and the total atrial septal length. 2.Short-axis view of the aorta: to observe the size of the septal defect and the length of the septal stump tissue on the aortic side and its contralateral side. 3.Biventricular inflow tract section: measure the size of the atrial septal defect, measure the length of the atrial septum, and observe the length of the tissue at the edge of the atrial septal defect. 4.Infrascleral two-ventricle cardiac section: To observe the size of the atrial septal defect, the length and thickness of the septal tissue at the edge of the atrial septal defect in the superior and inferior vena cava sites. Second, the main content of preoperative ultrasound examination: The parameters of defect type, location, number, morphology, size, length and thickness of tissue at the edge of the defect are obtained by examination on the above-mentioned sections. Third, the indicators suitable for interventional treatment: 1, secondary hole atrial defect; 2, defect diameter greater than 5mm and less than 34mm; 3, left-to-right shunt, not combined with severe pulmonary hypertension; 4, defect stump edge greater than 5mm mitral valve, tricuspid valve, coronary sinus opening and pulmonary vein more than 5mm; those who meet the above criteria, the success rate reaches more than 98%. Patients with unsuccessful interventional treatment mainly have no residual edge at the edge of the partial defect, i.e., the defect is not surrounded by an edge like a window, but is portal-shaped and partially edgeless. Therefore, whether the intervention can be performed successfully, the following points are the most important and the experience and experience formed by the lessons learned in the past 10 years: In the short-axis section of the aorta, the aortic side can have no edge, and the contralateral side of the aorta cannot have no edge, and no edge cannot be blocked successfully. If there is no edge on one side, the block cannot be successfully blocked. If there is no rim on the top of the atrium in the apical four-chamber cardiac section, the treatment cannot be blocked.