Tetralogy of Fallot is the most common form of cyanotic congenital heart disease, accounting for approximately 10% of all congenital heart diseases and 50% of cyanotic precocious heart diseases. The intracardiac malformations in Farrow’s syndrome include four malformations: ventricular septal defect, aortic span, pulmonary stenosis, and right ventricular hypertrophy. The severity of the lesions in FAL can vary widely, from severe atresia or near-atresia of the pulmonary artery with a large number of collateral vessels to a ventricular septal defect with mild stenosis of the outflow tract or pulmonary valve. Therefore, the timing and outcome of surgery for tetralogy of Fallot varies widely. According to statistics, 25%-35% of patients die within 1 year of age, 40%-50% die within 3 years of age, 70%-76% die within 10 years of age, 90% die within 20 years of age, and no more than 5% live beyond 40 years of age. Common causes of death include cerebrovascular accidents due to hypoxia, brain abscess, congestive heart failure, infective endocarditis, etc. Clinical manifestations Cyanosis: It is the main symptom of tetralogy of Fallot and is often seen in capillary-rich areas such as lips, finger (toe) nails, earlobes, nasal tips and oral mucosa. It is mostly inconspicuous at birth, and gradually becomes obvious after 3-6 months of life, or after 1 year of age, and gradually worsens with age. Respiratory distress and hypoxic attack: Children with low pulmonary blood and decreased blood oxygen levels can have shortness of breath and increased bruising with the slightest activity, such as breastfeeding, crying, emotional excitement, physical activity, and cold. Some children have a history of hypoxic attacks, which appear as a sudden onset after eating, crying or no obvious cause, with deepening and accelerating breathing, accompanied by a marked increase in cyanosis, and a weakening or disappearance of the heart murmur, and in severe cases, fainting, convulsions, or even death. The seizures are usually not related to the severity of cyanosis. The child’s motor tolerance is significantly lower than that of other children. Poor development: The physical growth is backward and some children are mentally retarded. Squatting: The patient squats after walking a few steps, which is rare in other deformities. Cyanosis with squatting is mostly diagnosed as Tetralogy of Fallot. Pestle-like fingers (toes): Due to long-term hypoxia, the capillaries at the ends of the fingers and toes are dilated and hyperplastic, and the local soft and bone tissues are also hyperplastic and hypertrophic, and the ends of the fingers (toes) are subsequently enlarged like drumsticks. Diagnosis Echocardiography can confirm the diagnosis of tetralogy of Fallot Treatment Surgery is the only method of treatment for tetralogy of Fallot. Depending on the development of the ventricles and pulmonary arteries of the child, surgery for tetralogy of Fallot can be a one-time radical procedure or a staged procedure. Only when the pulmonary vasculature is poorly developed and not suitable for radical surgery should palliative (i.e., body-pulmonary bypass) surgery be considered, and then radical surgery should be performed after the pulmonary vasculature has developed. A body-pulmonary bypass is a shunt created between the body circulation and the pulmonary circulation to increase blood flow to the pulmonary circulation, allowing for an increase in oxygenated blood. Palliative surgery does not change the malformation of the heart itself, but it can improve pulmonary blood flow, improve hypoxia, relieve symptoms, and promote the development of the pulmonary vasculature and ventricles, allowing the child to survive and creating conditions for future radical surgery. Radical surgery is effective, and the majority of children can fully resume normal life. In recent years, the mortality rate of radical surgery for tetralogy of Fallot has declined significantly, from 1% to 5% in infants and children to 1.3% to 14% in adults. Of course, this is related to the experience of the surgeon. The cardiothoracic surgery department of Xinhua Hospital has rich experience in the surgical treatment of tetralogy of Fallot, and the success rate of surgery is maintained at over 98%. The vast majority of patients recover well after surgery, bruising and hypoxemia can disappear immediately, pestle fingers (toes) gradually return to normal, and they can work and study normally, get married and have children without long-term medication. If adult patients with tetralogy of Fallot already have severe myocardial fibrosis, the postoperative period of low cardiac output will be longer. With the improvement of surgical techniques, the age and weight requirements of children have been gradually reduced, and children of any age and weight can undergo surgery if their condition requires it. The superiority of early surgery is to reduce secondary hypertrophy of the right ventricle and to promote pulmonary vascular development, but the young age and the ability to tolerate surgery are also small. It is believed that the timing of surgery is generally appropriate between 4 months of age and 1 year of age. If hypoxic episodes are frequent, early surgery is necessary to avoid death from hypoxic episodes; if there are few episodes, surgery can be performed when the child is a little older. In conclusion, surgery is the only option for patients with tetralogy of Fallot. Most patients with tetralogy of Fallot have excellent surgical results, with no or insignificant differences in long-term life expectancy and quality of life from normal children. Some patients with severe disease may have residual problems that require reoperation or medication to resolve, but quality of life can still be significantly improved.