Key Points

• Tetralogy of Fallot is a rare, complex congenital heart defect (a problem with the heart's structure that's present at birth).
• Tetralogy of Fallot involves four defects in the heart:
  • A large ventricular septal defect (VSD)
  • Pulmonary stenosis
  • Right ventricular hypertrophy
  • An overriding aorta
• Together, these four defects mean that not enough blood is able to reach the lungs to get oxygen, and oxygen-poor blood flows out to the body.
• Doctors don't know what causes most cases of tetralogy of Fallot. Certain factors during pregnancy, heredity, and some genetic disorders may increase the risk of having a baby with tetralogy of Fallot.
• Cyanosis, or a bluish tint to the skin, lips, and fingernails, is an important symptom of tetralogy of Fallot. Other symptoms include a heart murmur, slower-than-normal growth and development, and clubbing (a rounded shape to the skin or bone around the fingernails).
• An echocardiogram is an important test for diagnosing tetralogy of Fallot and for following the problem over time. This test helps diagnose problems with how the heart is formed and how well it's working. Other tests used to diagnose this defect include EKG (electrocardiogram), chest x ray, pulse oximetry, and cardiac catheterization.
• Tetralogy of Fallot must be repaired with open-heart surgery, either soon after birth or later in infancy. Some babies who are very small or weak have a temporary procedure that improves blood flow to the lungs and gives the baby time to grow and get strong enough for the full repair.
• Treatment involves widening or replacing the pulmonary valve and enlarging the passageway from the right ventricle to the pulmonary arteries. These procedures improve the flow of blood to the lungs, allowing it to pick up enough oxygen for the body's needs. Surgeons also close the VSD with a patch. The patch stops the mixing of oxygen-poor and oxygen-rich blood in the ventricles. Fixing these two defects resolves problems caused by the other two defects.
• Advances in treatment mean that most children born with tetralogy of Fallot grow to adulthood. They need lifelong care by trained specialists to stay as healthy as possible.
• Adults who had surgery to repair tetralogy of Fallot may have long-term heart problems, such as heart function problems, arrhythmias, or problems resulting from the original repair. These problems are treated with medicines, procedures, and surgery.