Tetralogy of Fallot Definition, Reason, Symptoms, Treatment & Prevention

Tetralogy of Fallot Definition, Reason, Symptoms, Treatment & Prevention


Tetralogy of Fallot (TOF) is a condition in which there are four abnormalities in the heart of a newborn baby at once. This disorder is classified as congenital and can affect the growth and development of the child if not treated properly.

Babies who experience TOF generally look bluish because the blood flowing in their bodies doesn’t have enough oxygen. Blood that has enough oxygen levels will be bright red.

Heart surgery can correct this TOF-related disorder. However, some people are still advised to limit activity to prevent the heart from working too hard.

Although the exact cause is unknown, several factors can increase the risk of developing TOF:

  • Viral infections during pregnancy, eg rubella
  • Alcohol consumption during pregnancy
  • Malnutrition in pregnant women
  • Mother’s age is more than 40 years when pregnant
  • History of TOF in the elderly
  • Down syndrome

Tetralogy of Fallot Symptoms

Symptoms of Tetralogy of Fallot (TOF) include:

  • Bluish skin
  • Shortness of breath when eating, feeding and doing activities
  • Faint
  • Clubbing fingers or changes in the shape of the fingertips to become more rounded and the nails turn pale
  • Hard to gain weight
  • Easily tired when moving or playing
  • Fussy
  • A heart murmur is heard
  • Sometimes, a child’s skin becomes very blue when crying or doing strenuous activities. This happens because the oxygen level in the body drops drastically, being used up for the body’s work. These children will usually squat spontaneously. Squatting position will help increase blood flow to the lungs to reduce tightness.

Tetralogy of Fallot Reason

Tetralogy of Fallot (TOF) means there are four abnormalities in the heart in the form of:

  • Pulmonary valve stenosis. Pulmonary valve stenosis is a narrowing of the pulmonary valve – the separation between the pulmonary artery and the right ventricle. This narrowing can cause an interruption of blood flow to the lungs.
  • Ventricular septal defect ( VSD)

Imperfect formation of the septum between the right and left ventricles.

As a result, blood in the left ventricle which is rich in oxygen can mix with blood in the right ventricle which is poor in oxygen and contains lots of carbon dioxide. This makes the blood flowing throughout the body no longer contain enough oxygen.

  • Overriding aortaThe large blood vessel that carries blood throughout the body (aorta) attaches to the right ventricle. However, in TOF, this blood vessel is shifted to the right, just above the ventricular septal defect.
  • Right ventricular hypertrophy

In TOF there is enlargement of the right ventricular wall due to the hard work of pumping blood out of the heart. The result can be impaired heart function and it is not impossible to lead to heart failure.


Tetralogy of Fallot (TOF) can be suspected as one of the causes when the baby’s skin looks bluish. On physical examination, a heart murmur will be found due to irregular blood flow in it.

To confirm the diagnosis of TOF, several additional tests are needed, such as:

  • Echocardiographic

Ultrasound of the heart is needed to see the regularity of blood flow in the heart and also to assess the function of parts of the heart such as septum, valves and blood vessels around the heart.

  • Electrocardiography (EKG)

EKG is needed to see electrical activity in the heart muscle. Irregular heart rhythms and an enlargement of one of the chambers of the heart can be seen through this examination.

  • Chest Xray

On a chest x-ray, you can see a boot-like appearance due to an enlarged right ventricle.

  • Oximetry

Oximetry is a tool used to measure oxygen levels in the body.

  • Cardiac catheterization

Cardiac catheterization is generally performed before major surgery is performed. This examination aims to assess the structure of the heart and plan the right treatment.

Tetralogy of Fallot Treatment

The only way to restore heart function is with a surgical procedure. Surgery is generally performed before the child is 1 year old and uses various methods to correct heart defects.

Insertion of a septum is performed to correct the VSD and dilation or replacement of the valve is also performed to treat pulmonary valve stenosis. Slowly, the wall thickness of the right ventricle will return to normal after heart function is restored.


Various complications can occur if TOF is not handled optimally. These complications are:

  • Growth failure
  • Endocarditis, an infection of the heart wall due to a bacterial attack
  • Death from heart failure


Because the exact cause is not known, tetralogy of Fallot cannot be completely prevented. It’s just that by avoiding the risk factors, the possibility of this disorder can be avoided as much as possible.

Leave a Comment