What Is the Natural History of Tetralogy of Fallot?

Tetralogy of Fallot is a congenital heart condition that affects the structure of the heart and causes oxygen-poor blood to flow to the body. This condition is relatively rare and affects approximately 1 in every 2,000 babies. In this article, we will discuss the natural history of Tetralogy of Fallot and how it progresses over time.

What Is Tetralogy of Fallot?

Tetralogy of Fallot is a heart condition that consists of four distinct defects in the heart. These defects include:

Ventricular Septal Defect (VSD) – A hole in the wall that separates the two lower chambers (ventricles) of the heart.

Pulmonary Stenosis – A narrowing or blockage in the pulmonary valve or pulmonary artery, which restricts blood flow to the lungs.

Right Ventricular Hypertrophy – An enlargement of the right ventricle due to increased workload caused by pulmonary stenosis.

Overriding Aorta – The aorta, which is responsible for carrying oxygen-rich blood from the heart to the rest of the body, is positioned directly above or between both ventricles instead of only above the left ventricle as it should be.

Natural History

The natural history of Tetralogy of Fallot varies from person to person. Some individuals may have mild symptoms and lead relatively normal lives while others may require multiple surgeries throughout their lifetime.

Infancy and Childhood

Symptoms typically become evident during infancy or early childhood. Babies may experience cyanosis (bluish tint to skin due to lack of oxygen) during feeding or crying, difficulty breathing, poor weight gain, and fainting spells. Children may also be prone to infections in their respiratory system due to their weakened heart.

Adolescence and Adulthood

As individuals with Tetralogy of Fallot reach adolescence and adulthood, they may become more symptomatic. They may experience shortness of breath, chest pain, fainting spells, and arrhythmias (irregular heartbeat). These symptoms can impact their daily life and lead to a decreased quality of life.

Surgical Intervention

Surgical intervention is usually required to correct Tetralogy of Fallot. The first surgery typically occurs within the first year of life and involves creating a shunt to increase blood flow to the lungs. This allows time for the child to grow before more complex surgeries are performed.

The second surgery, which typically occurs between 1-3 years of age, involves repairing the VSD and widening the pulmonary valve or artery.

If necessary, additional surgeries may be required as the individual grows older due to valve or conduit deterioration or other complications.


In conclusion, Tetralogy of Fallot is a complex heart condition that requires surgical intervention. The natural history of this condition varies from person to person but typically requires multiple surgeries throughout an individual’s lifetime. It is important for individuals with Tetralogy of Fallot to receive proper medical care and monitoring throughout their lives.