Congenital heart disease is the most common type of congenital malformation. Except for a few small ventricular septal defects that have a chance of self-healing before the age of 5 years, the majority require surgical treatment. The main clinical manifestations are cardiac insufficiency, cyanosis, and dysplasia. Some children with precordial disease still have murmurs after surgery, and parents may be nervous or not understand what is going on. The reasons for this are described below. For children with simple precordial disease after radical surgery, due to the use of patches during surgery or the de-cannulation of the right ventricular outflow tract and the removal of some hypertrophic muscle bundles, local blood flow may not be smooth or there may be eddy currents, so there may still be murmurs after surgery, but the nature of these murmurs is different from those before surgery, so there is no need to be alarmed; in addition, some children may have residual shunts or stenosis or incomplete closure of valves after surgery, which may also have murmurs. In addition, some children may have residual shunts or stenosis or incomplete closure after surgery, which may also result in murmurs, and these children need to be followed up regularly to continue to observe changes in their condition. In children with complex malformations, some of them have had only palliative surgery (e.g., Glenn and Banding surgery), and the intracardiac structures are the same as before surgery, and the murmur is the same as before surgery; and in children who have had a body-pulmonary shunt, because a shunt duct has been established between the pulmonary artery and the aorta, the shunted blood flows from the aorta to the pulmonary artery during both systole and diastole, so an additional murmur will be produced after surgery, and such murmurs The murmur is often continuous, and these children, if the murmur disappears, prove that the shunted duct is likely blocked and require prompt medical attention.