Atrial septal defect It is generally believed that asymptomatic patients with simple ASD should be corrected by elective surgery between 3 and 5 years of age. Asymptomatic patients with congestive heart failure, recurrent pulmonary infections, or those with echocardiography suggestive of volume overload and right heart catheter suggestive of pulmonary/body flow ratio >1.5 may undergo ASD repair in infancy. ASDs less than 5 mm in diameter are not hemodynamically significant and may not require surgery for life. Ventricular septal defect About 30% of patients with simple VSD have serious symptoms in infancy, such as feeding difficulties, congestive heart failure that is difficult to treat with medication, recurrent pulmonary infections, etc., which require timely surgical treatment, and larger VSDs with combined pulmonary hypertension should be treated surgically in infancy to prevent the development of pulmonary hypertensive lesions that may affect the surgical outcome. In VSD with large left-to-right shunts, even in infancy, it is advisable to perform closure surgery if possible. However, in some small infants, such as those with high risk of extracorporeal circulation, pulmonary artery stenosis can be performed, and then VSD repair with removal of the stenosis can be performed after the general condition has improved. Ventricular septal defect is a common congenital heart malformation, mostly a single malformation, accounting for about 20% of congenital heart disease; it can also be a component of a complex heart malformation, as seen in tetralogy of Fallot, complete atrioventricular channel, etc. The description in this section is limited to simple ventricular septal defects. Atrial septal defects are a more common form of congenital heart disease. A subset of smaller cases of foramen ovale type 2 septal defects may close on their own within 1 year of birth and are very unlikely to close on their own 2 years after birth. Preventive care of ventricular septal defect This disease is a congenital disease, and there is no effective preventive measure, so early detection and early diagnosis and treatment should be achieved. For patients with ventricular septal defect, the prognosis is good, and the natural life expectancy can be more than 70 years; small ones may even close by themselves before 10 years old, and those with large defects can have heart failure when they are 1-2 years old, and those with pulmonary hypertension have poor prognosis. For surgical treatment, those with clear diagnosis should be operated early, around 5 years old is the ideal time; those with pulmonary hypertension still with left-to-right shunt should strive for surgery; however, those with severe pulmonary hypertension and right-to-left shunt should be considered as contraindications for surgery. The prognosis for surgery is generally good. Some of the smaller cases of foramen ovale septal defects may close on their own within 1 year after birth, and it is very unlikely that they will close on their own 2 years after birth. Surgery should be considered in cases of pure atrioventricular septal defect or atrioventricular septal defect with partial right pulmonary vein ectopic reflux and a ratio of pulmonary to body circulation blood flow exceeding 1.5:1. The most appropriate age for surgery is 4 to 5 years old, and early surgical treatment can prevent elevated pulmonary resistance and right heart failure. In infants and children who present with congestive heart failure and whose heart failure is not controlled by medical procedures, surgery is required as early as possible. Pulmonary circulatory resistance is significantly elevated, reaching more than 6 Wood units at rest, and does not decrease or increases further after exercise. Surgical treatment is contraindicated in cases presenting clinically with cyanosis, showing reverse shunt at the atrial level, and further decrease in arterial oxygen saturation after exercise.