Tetralogy of Fallot (blue baby syndrome) is one of the most common cyanotic congenital heart diseases. This condition is characterized by four fundamental structural abnormalities present simultaneously in the heart: a ventricular septal defect (VSD), which is a hole between the ventricles; an overriding aorta, where the aorta is positioned over both ventricles; an obstruction of the right ventricular outflow tract; and thickening of the right ventricular muscle wall. The combination of these four findings makes Tetralogy of Fallot a complex congenital heart disease.