Tetralogy of Fallot is the most common cyanotic congenital heart disease, consisting of four abnormalities: ventricular septal defect, obstruction of the right ventricular outflow tract, overriding aorta, and right ventricular hypertrophy. Several complications are prone to occur in Tetralogy of Fallot: Firstly, due to the increase in red blood cells, embolism can occur, especially cerebral embolism is the most common. Children over two years old can also develop brain abscesses. Secondly, bacterial endocarditis often occurs at sites such as the right ventricular infundibulum, pulmonary valve, or aortic valve.