Tetralogy of Fallot (TOF) | William G. & Mary A. Ryan Center for Heart & Vascular Medicine | Loyola Medicine

Tetralogy of Fallot (TOF)

Overview and Facts about Tetralogy of Fallot (TOF)

Tetralogy of Fallot (TOF) is a rare condition that is caused by a combination of four congenital heart defects. The defects impact the heart’s structure, causing oxygen-low blood to pump throughout the body. Because their blood doesn’t carry sufficient oxygen, infants with this disorder have blue-tinged skin.

Signs and Symptoms of Tetralogy of Fallot (TOF)

Typically, TOF is diagnosed during or soon after infancy. However, in some cases, it may not be detected until adulthood. This will depend on the severity of the defects. TOF is caused by the following four heart defects:

  • A hole in the wall between the heart’s two lower chambers (ventricles)
  • A narrowing of the main pulmonary artery and the pulmonary valve
  • An enlargement of the valves opening to the aorta
  • A thickening of the wall of the heart’s lower right chamber (ventricle)

TOF may cause:

  • An increased risk of heart infection
  • Seizures
  • Dizziness and fainting
  • Delayed growth and development

Causes and Risk Factors of Tetralogy of Fallot (TOF)

The cause of TOF in infants is not known. It is thought to be a combination of genes and environmental factors.

Tests and Diagnosis of Tetralogy of Fallot (TOF)

Usually, TOF is diagnosed during pregnancy or soon after birth. Prenatal tests check for this type of birth defect. It may be seen during an ultrasound. An echocardiogram of the fetal heart can also show TOF.

TOF may be diagnosed after the infant is born if the infant’s skin turns blue during feeding or crying. This type of episode is known as a tet spell. A physician may suspect an infant has TOF if the child has blue-tinged skin or a heart murmur. An echocardiogram will confirm this condition.

Treatment and Care for Tetralogy of Fallot (TOF)

Typically, TOF is corrected with surgery soon after the birth of the child. During the procedure, the surgeon will widen the pulmonary valve and passage to the pulmonary artery. A patch will be used to close the hole between the heart’s lower chambers. These actions will improve blood flow throughout the body.

After surgery, most infants live healthy lives. As they get older, they will need to make regular visits to a cardiologist to monitor for further heart conditions.