Ventricular septal defect is the most common congenital heart disease. According to the size of the defect, ventricular septal defects are classified as small, medium, and large. The clinical manifestations also vary according to the size of the defect: 1. small defects: basically asymptomatic, growth and development are not affected, only murmurs can be heard during physical examination. 2. medium and large defects: due to the high fractional flow, the manifestations of insufficient body circulation appear quickly, growth and development are delayed, feeding is difficult, emaciation, weakness and shortness of breath after activity, easy to recurrent respiratory infections, and congestive heart failure easily occurs. The patient is prone to congestive heart failure. During physical examination, a distinct heart murmur and enlarged heart borders can be heard.