I. Indications for interventional treatment of patent ductus arteriosus 1. narrowest internal diameter of PDA > 2 mm; 2. age usually ≥ 6 months, weight ≥ 4 kg; 3. left-to-right shunts not combined with other cardiac malformations requiring surgery; 4. post-surgical residual shunts. Second, the contraindications to interventional treatment of patent ductus arteriosus 1, infective endocarditis, PDA with redundancy; 2, severe pulmonary hypertension with right-to-left shunts; 3, combined with the need for surgical intracardiac malformations and dependent PDA. Third, the procedure 1, preoperative preparation: (1) electrocardiogram, X-ray chest X-ray, echocardiography; (2) routine blood, urine, fecal and liver and kidney function tests (2) routine blood, urine, fecal and liver and kidney function tests to exclude contraindications to surgery; (3) informed consent for surgery signed by the patient and his family; (4) intravenous antibiotics 1 day before surgery. (2) Diagnostic cardiac catheterization: (1) Anesthesia: local anesthesia with lidocaine. (2) Right heart catheterization: puncture the right femoral vein, the heart catheter is passed through the femoral vein to the inferior vena cava, right atrium, right ventricle and pulmonary artery, and the right ventricular and pulmonary artery pressure is measured. (4) Amplatzer blocker selection and delivery: Select a blocker that is 2-4 mm (up to 6 mm in children) larger than the narrowest diameter of the measured PDA, attach it to the tip of the delivery wire, and deliver it to the descending aorta along the delivery sheath. After the fixation disk of the blocker is fully opened, the delivery sheath is retracted to the aortic side of the PDA together with the delivery wire. If the blocker is successfully occluded, the blocker can be released by manipulating the rotating handle and the right heart catheterization can be repeated. -Descending aortic pressure. Withdraw the sheath to stop the hemorrhage by compression. (5) Indicators of successful PDA occlusion: no residual shunt – complete occlusion; minimal filling of the distal pulmonary artery with contrast but not in the form of jets is a minimal residual shunt; minimal filling of the distal pulmonary artery with contrast in the form of jets is a small residual shunt. The disappearance of the auscultatory murmur or the retention of only a grade 1 systolic murmur also indicates successful occlusion.