Precocious heart disease is the result of abnormal development of a part of the cardiovascular system in the fetus at a certain period of time, and so far, it is not certain whether there is a genetic component. Abnormal reactions of the pregnant woman’s body to the outside world during pregnancy, such as allergies and high fever, may affect the development of the fetal cardiovascular system, but only during the first trimester. Once the fetal cardiovascular system has been formed, these factors do not play a role. (1) How to detect precordial disease? Properly trained midwives are generally able to detect precordial disease in newborns, such as large ventricular septal defects, unclosed ductus arteriosus, and complex precordial disease with cyanotic faces. A proportion of children are detected after 3-6 months of life or after 1 week of age. The children have rapid breathing and heartbeat, difficulty in breastfeeding, impaired growth and development, cyanosis or fainting when crying. The sick child is frail and sickly, with recurrent fever and lung infections during seasonal changes. The disease also develops with overeating or excessive activity or crying during normal times. The symptoms resemble a cold or pneumonia, but are actually triggered by cardiac insufficiency. Children aged 1-2 years who have frequent attacks should seek prompt medical attention to obtain an accurate diagnosis and timely surgical treatment. (2) To know if the condition is worsening: Some children grow up to be 2 or 3 years old and have fewer attacks and increased activity, which is not necessarily a good sign. This is because precardiac disease is broadly divided into two categories: one without cyanosis and the other with cyanosis. In the more severe cases, the small vessels in the lungs change during growth, with pulmonary hypertension in those without cyanosis and embolism of the small vessels in those with cyanosis. Both types of precardiac disease have increased intrapulmonary vascularity. In children with cyanosis, there is more blood in the lungs and the symptoms are relieved for a while, so parents mistakenly think that the condition is improving; in children without cyanosis, the symptoms worsen and cyanosis or coughing up blood appears. (3) How to treat? Parents should have the knowledge and attitude towards treatment. In principle, precordial disease should be treated by surgery in time, and early treatment should be done as soon as possible. Generally, according to the degree and location of cardiovascular malformation, precardiac disease is divided into simple (such as patent ductus arteriosus, atrial defect, ventricular defect) and complex (or compound) precardiac disease (such as tetralogy of Fallot, tricuspid atresia, pulmonary atresia, transposition of the great arteries, etc.). There are mild, moderate, and severe cases in both types of precordial disease. Therefore, although the disease name is the same, there is a difference in the severity of the disease for each child. Treatment also varies. Some do not need immediate surgery and can be followed up and examined regularly; others need immediate surgery. The method and outcome of surgery also vary. Some can be cured after surgery, while others only improve. To date, the results of surgery for a few severe and complicated precardiac diseases are uncertain or even untreatable. Parents understand the above treatment principles and must cooperate well with the hospital to treat their children without losing time and reduce doubts about the advice and results of treatment; also, they will not be afraid of danger or heartache for their children to make up their mind.