Congenital heart disease is a cardiovascular malformation caused by abnormal development of the heart vessels during fetal life, and 8 out of every 1,000 people suffer from congenital heart disease. Because the condition of congenital heart disease may produce various complications during the growth process, some damage the cardiopulmonary function of the sick child, some lose the time to treat surgically as a result, and some cause disability or even death. Parents of children with congenital heart disease should be more vigilant, pay high attention and take precautions. What complications can congenital heart disease cause? 1, lung infection is the most common complication, cough and shortness of breath are the common symptoms of pneumonia. Many children are often diagnosed with congenital heart disease because of pneumonia, but heart disease is the root cause of pneumonia. For example, ventricular septal defect, arteriovenous ductus arteriosus and atrial septal defect are common, causing congestion in the lungs of children, elevated pressure in the pulmonary arteries, and therefore water leakage into the interstitial space of the alveoli, increasing water and blood flow in the lungs and causing labored breathing and coughing. If congenital heart disease is not treated, pneumonia and heart failure can recur, causing the child to become critically ill several times or even die. 2, heart failure Heart failure as a serious complication, refers to the heart can not provide enough blood to supply the physiological needs, so the use of some compensatory mechanisms to compensate for the lack of heart function, if the compensatory function is not effective, more heart failure, leading to the emergence of various symptoms, such as reduced mobility, increased heart rate, shortness of breath, frequent cough, laryngeal or croup sounds, liver enlargement, jugular vein anger and edema, etc. Those with decreased cardiac function need to be treated as soon as possible. 3.Pulmonary hypertension Congenital congestive heart disease in which blood is shunted from the left to the right in large quantities, resulting in increased blood flow in the pulmonary circulation and increased pressure in the pulmonary arteries. In other words, even if the heart disease is cured by surgery, the pulmonary artery pressure is still high. Therefore, it is generally believed that if a child with congenital heart disease is operated on within 2 years of age, the pulmonary artery pressure can recover after surgery. In addition, if the pulmonary artery pressure continues to rise above the pressure of the body circulation, it will produce a right-to-left shunt of blood, and the child will appear cyanotic, and the opportunity for surgery will have been lost. 4. Infective endocarditis Refers to inflammation of the endothelium, valves, or intima of the heart, and occurs mostly in patients with congenital or acquired heart disease. The endocardium is subjected to the impact of blood flow for a long time, which causes rough endocardium and makes platelets and fibrin to gather and form redundancy. Pathogenic bacteria in the blood grow and multiply in the redundancy, and patients may show septic symptoms, such as persistent high fever, chills, anemia, hepatosplenomegaly, cardiac insufficiency, and sometimes embolic manifestations, such as skin bleeding spots and pulmonary embolism. If antibiotic treatment is not effective, surgery is needed to remove the abnormalities and abscesses, correct the malformations in the heart or replace the diseased valves, which is risky. 5. Cerebral thrombosis and brain abscess are among the most serious complications of tetralogy of Fallot. Due to long-term hypoxia and cyanosis in children with tetralogy of Fallot, thus increasing red blood cells, increasing blood cell pressure, thick blood and slow blood flow, creating conditions for the formation of thrombus in the cerebral vessels, which can form infectious thrombus if secondary infection occurs, or cause bacterial infection to form brain abscess due to hypoxia and softening of brain tissue, manifesting as severe headache, vomiting, impaired consciousness and hemiparesis. 6, hypoxia The tetralogy of Fallot is more common. When the child is born, cyanosis is not obvious, or only appears when crying, and gradually appears and worsens 3 months-6 months after birth. Children often have squatting, which is manifested as squatting after trying to walk a certain distance, with both lower limbs flexed and both knees against the chest. Severe patients (about 20%-70%) have a history of hypoxic episodes, with clinical manifestations of sudden onset, pallor, weakness of the limbs, shortness of breath and difficulty, fainting and even convulsions in severe cases, resulting in hypoxic death due to severe hypoxia. The duration of hypoxic episodes varies, and they usually resolve spontaneously, but frequent episodes are a great threat to the child. Severely ill children with hypoxic episodes should be operated on as early as possible, and those with frequent episodes should be operated on urgently.