Tetralogy of Fallot is one of the most common forms of complex congenital heart defects that causes cyanosis, or a blue baby. Tetralogy of Fallot is comprised of four separate components.
- The first one is a ventricular septal defect (VSD).
- The second one is pulmonary stenosis (PS).
- The third component is right ventricular hypertrophy, which is an increase in the size of the right ventricle.
- The final component is an overriding aorta, which means that the aorta lies directly over the ventricular septal defect.