Tetralogy of Fallot is defined by four anatomic changes: pulmonary stenosis, ventricular septal defect, dextroposition of the aorta, and right ventricular hypertrophy. It is the most common cyanotic congenital heart disease, accounting for 10% of all congenital heart defects. Cyanosis appears shortly after birth or in early infancy due to right-to-left shunting of venous blood from the right ventricle into the dextroposed aorta. The aorta overrides the ventricular septal defect and receives blood from both ventricles. Narrowing of the pulmonary artery impedes the entry of blood into the lung, thereby increasing the pressure in the right ventricle. None of the other choices exhibit this particular constellation of congenital heart defects.Diagnosis: Tetralogy of Fallot