Congenital heart disease is a common condition that can be cured or reduced through surgery. This allows the child to grow and develop normally. Because the condition of congenital heart disease can produce various complications, some of which damage the heart and lung function of the child, some of which lose the opportunity for surgery, and some of which cause disability or even death. So, what are the complications that can easily arise from congenital heart disease? Pneumonia cough and shortness of breath are common symptoms of pneumonia, and many children are often clinically diagnosed with congenital heart disease because of pneumonia, but in fact heart disease is the bane of pneumonia. In the congenital heart disease of pulmonary congestion where blood is shunted from left to right, such as common ventricular septal defect, arteriovenous ductus arteriosus and atrial septal defect, the lungs of the children are congested and the pressure of the pulmonary artery is elevated, thus causing water to leak into the interstitial space of the alveoli, increasing water and blood flow in the lungs, and the lungs tend to fill up and lose compliance, resulting in labored breathing and choking. When the heart function is affected, it causes pulmonary stagnation and edema, based on this, a minor upper respiratory tract infection can easily cause bronchitis or pneumonia, which often coexist with heart failure, such as antibiotic treatment alone is difficult to see the effect, need to control heart failure at the same time to relieve, congenital heart disease if not treated, pneumonia and heart failure can recur, resulting in the child’s repeated critical illness and even death. Heart failure means that the heart cannot provide enough blood to meet the physiological needs, so some compensatory mechanisms are used to make up for the lack of heart function. If the compensatory function is not effective, the heart will fail even more, leading to various symptoms such as increased heart rate, shortness of breath, frequent coughing, laryngeal or croupy sounds, enlarged liver, jugular vein anger and edema. Pulmonary hypertension is a 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 children with immature fetal-type blood vessels and based on long-term tolerance of high flow and high pressure, the body produces a protective response, prompting pulmonary vasoconstriction and pressure increase to reduce the left-to-right shunt, however, it has been long days followed by pulmonary hypertension, which eventually causes irreversible 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, a right-to-left shunt of blood will occur and the child will appear cyanotic and the opportunity for surgery will have been lost. Infective endocarditis refers to inflammation of the lining of the heart, valves or vessels, and occurs in children with congenital or acquired heart disease. In pediatric congenital heart disease, the order of the most frequent diseases is: ventricular septal defect, patent ductus arteriosus, tetralogy of Fallot, and valvular disease. Among its predisposing factors bacteremia is a prerequisite for the pathogenesis, such as respiratory tract infection, urinary tract infection, tonsillitis, gingivitis, and its causative organisms are commonly streptococci, staphylococci, pneumococci, and gram-negative bacilli. The endocardium is operated by the impact of blood flow for a long time, which will cause roughness of the endocardium in that area, so that platelets and fibrin will gather and form superfluous organisms, and the pathogenic bacteria in the blood will grow and multiply in the superfluous organisms, and the children may show symptoms of sepsis, such as persistent high fever, chills, anemia, hepatosplenomegaly, cardiac insufficiency, and sometimes embolic manifestations, such as bleeding spots on the skin, pulmonary embolism, etc. If antibiotic treatment is not effective, surgery is required to remove the abnormalities and abscesses, correct the intracardiac malformations or replace the diseased valves, which is very risky and has a high mortality rate. Hypoxic attack of tetralogy of Fallot is a congenital cardiovascular complex malformation, which is the most common type of cyanotic congenital heart disease in children, the disease is not obvious at birth, but gradually appears and worsens 3 months-6 months after birth, the child’s shortness of breath increases after feeding, crying, walking and activity, about 20%-70% of children have a history of hypoxic attack, the clinical manifestations are sudden onset, shortness of breath and difficulty. The clinical manifestations are sudden onset, difficulty in breathing, cyanosis, fainting and convulsions in severe cases, and death due to hypoxemia caused by severe hypoxia. The duration of hypoxic episodes varies, and they usually resolve spontaneously, but they can occur frequently and are very threatening to the child. Cerebral thrombosis and brain abscess are among the most serious complications of tetralogy of Fallot. Due to long-term hypoxia and cyanosis, children with tetralogy of Fallot have more red blood cells, higher blood cell pressure, thicker blood, and slower blood flow, creating conditions for the formation of thrombus in the cerebral vessels, which can lead to infectious thrombosis if secondary infection occurs, or brain abscess due to bacterial infection caused by softening of brain tissue due to hypoxia, manifesting as severe headache, vomiting, impaired consciousness, and hemiparesis.