Infants and children with precordial disease do not have the same symptoms that adults often have, such as palpitations and precordial pain. The symptoms of precordial disease vary among infants and children, and the detection of precordial disease is based on three main clinical manifestations: cyanosis, heart murmur, and cardiac insufficiency. However, not all children with precocious heart disease have the above three manifestations, while children with precocious heart disease also have some symptoms and signs that deserve attention. 1, cyanosis: there are many causes of cyanosis, in neonates first consider pulmonary diseases, such as aspiration pneumonia, respiratory distress syndrome, diaphragm, pneumothorax, etc., neurological diseases, even shock, sepsis, etc., can also be caused, should be excluded. General rule; severe cyanosis after birth include: tricuspid atresia, complete transposition of great vessels, pulmonary atresia. Moderate cyanosis appears within one week after birth: complete transposition of great vessels, pulmonary atresia with ventricular septal defect. Progressive cyanosis is aggravated by: tetralogy of Fallot, complete pulmonary vein ectopic drainage. Cyanosis occurs after infancy: left-to-right shunt precordial disease combined with pulmonary hypertension. 2. Heart murmur: Heart murmur is a common major sign of precordial disease, but hearing heart murmur does not always mean that there is precordial disease. Early neonatal murmur can be temporarily closed arterial duct murmur (most of its arterial duct can be closed by itself); murmur with normal pulmonary valve second sound often suggests a functional murmur; no murmur can not completely rule out precardiac disease, no murmur in the neonatal period, but the second sound of the pulmonary valve is enhanced or weakened often suggests precardiac disease; some precardiac heart murmur or murmur soft, but with cyanosis, heart failure, often The most common cause of murmurs heard after birth is pulmonary stenosis (PS); murmurs heard after 3-6 weeks of life are often PDA (patent ductus arteriosus) and VSD (ventricular septal defect). 3, cough, shortness of breath, pneumonia: cough and shortness of breath are common symptoms of respiratory diseases, and are also common symptoms in children with precordial disease, especially in children with left-to-right shunt precordial disease. Due to left-to-right shunt or pulmonary vein obstruction, pulmonary blood increases and the bronchial walls become congested and edematous, resulting in increased accumulation of exudate in the trachea, causing cough and shortness of breath due to insufficient oxygen supply. Enlargement of the left atrium compressing the bronchial wall can also cause coughing. In the case of more blood in the lungs, minor upper respiratory tract infections can easily cause bronchitis and pneumonia, and they do not easily get better and recur. 4. Hoarseness and dyspnea: When pulmonary hypertension is present, the dilated pulmonary artery can form compression on the left recurrent laryngeal nerve, causing hoarseness in the child, and low crying is seen in small infants; reduced pulmonary compliance, hypoxemia, and increased functional dead space are the main causes of dyspnea. Respiratory distress in small infants can be manifested as shallow and rapid breathing, weakness in sucking, interruption of sucking due to shortness of breath before sucking is completed, or choking due to respiratory distress and prolonged breastfeeding time. 5. Growth retardation and reduced activity endurance: Children with precordial disease have growth retardation due to insufficient blood volume and blood oxygen supply in the body circulation, and the weight lag is more obvious than the length, which also causes reduced activity endurance. 6.Anoxic attack: Most often seen in infants with severe cyanosis over 3-4 months of age, often occurring during breastfeeding, violent crying, and straining to defecate. 7, mortar and pestle finger: the end of the finger (toe) soft tissue thickening like drumstick-like expansion, the nail bed is arch-shaped elevated purple-gamma color, known as mortar and pestle finger (toe), rare in infants, generally cyanotic preconditioned children after 2-3 years of age. 8, squatting: generally seen in tetralogy of Fallot, appearing after being able to walk at about 1 year of age, and manifesting in infancy as side sleep in a flexed position. Hemoptysis and edema are common in severe cyanotic preconditioning. 9, other: newborns with unexplained pallor, limb weakness, weak pulse, weight gain should be ruled out the possibility of precordial disease.