The right ventricular outflow tract, a relatively common congenital heart malformation disease, is also known as tetralogy of Fallot. in 1944, Blalock first applied a bypass operation with subclavian artery and pulmonary anastomosis to reduce cyanosis. in 1954, Lillehei first obtained success in controlled cross circulation and intracardiac performance of tetralogy of Fallot under direct vision. According to statistics, 3.6 infants with this disorder are found per 10,000 deliveries, accounting for 12% to 14% of congenital visceral diseases. Associated disorders include myocardial infarction complicated by ventricular septal penetration, myocardial infarction complicated by left ventricular ventricular wall tumor, intraventricular conduction block, ventricular septal defect, left ventricular double outlet, right ventricular double outlet, ventricular myocardial densification insufficiency, ventricular quiescence, ventricular flutter and ventricular fibrillation. The two main anatomic anomalies of tetralogy are right ventricular outflow tract stenosis and ventricular septal defect both of which are quite variable. Right ventricular outflow tract stenosis can be located in the funnel, pulmonary valve, pulmonary valve annulus, main pulmonary artery or pulmonary artery branches, and in some cases, both stenoses can be present. The disease is most often seen in children and the most common main clinical signs are cyanosis and blood hypoxia. The timing and severity of the clinical symptoms depend on the degree of right ventricular outflow tract obstruction and the amount of pulmonary circulation flow. In the short period after birth, cyanosis often does not appear clinically because the ductus arteriosus is not yet closed and pulmonary flow can come from the unclosed ductus arteriosus. In the vast majority of cases, cyanosis begins to appear weeks or months after birth when the ductus arteriosus is closed and gradually worsens. However, cyanosis may be present after birth if the right ventricular outflow tract obstruction is severe, such as pulmonary atresia, diffuse dysplasia of the outflow tract, and multiple severe stenoses of the funnel, pulmonary valve annulus, and pulmonary valve. If the right ventricular outflow tract obstruction is mild and the right-to-left blood shunt is low, cyanosis is mild, and if the left-to-right blood shunt is predominant at the ventricular level, cyanosis may not be present. Cyanosis worsens with feeding, crying, and activity, and respiratory distress occurs.