Tetralogy of Fallot

Tetralogy of Fallot is a complex congenital heart defect that involves four structural abnormalities in the heart.

This condition impacts the heart’s anatomy and its ability to circulate oxygen-rich blood throughout the body.

Tetralogy of Fallot is a congenital condition, meaning a child is born with it. Usually, it happens by chance, without any known cause or risk factor. Detecting and treating tetralogy of Fallot is important to ensure the health of a child’s heart.

What is tetralogy of Fallot?

Tetralogy of Fallot is a combination of four congenital heart defects that occur together:

• Ventricular septal defect (VSD): A hole between the heart’s lower chambers
• Pulmonary stenosis: Narrowing of the pulmonary valve and artery
• Right ventricular hypertrophy: Thickening of the muscle of the right ventricle
• Overriding aorta: The aorta is positioned directly over the VSD, on the right side, instead of where it should be, on the left side of the heart

These defects cause oxygen-poor blood to flow out of the heart and into the rest of the body, leading to symptoms such as cyanosis (bluish skin), shortness of breath, and fatigue.

Causes of tetralogy of Fallot

Tetralogy of Fallot is present at birth and is one of the more severe congenital heart defects. The exact cause is unknown, but genetic and environmental factors may play significant roles.

Birth defects: What to know, from head to toe>>

Diagnosis and treatment

Tetralogy of Fallot is a rare condition that can be detected before birth or after.

Treatment is complex, so finding a skilled team with experience in surgery for congenital heart defects is essential

Diagnosis

Tetralogy of Fallot is typically diagnosed either during an ultrasound in pregnancy, or within the first few weeks after birth.

Doctors may use various methods, such as:

• Echocardiogram: An ultrasound of the heart to view its structure and function
• Electrocardiogram (ECG): A test to measure the electrical activity of the heart
• Chest X-ray: Observes the heart’s size and any abnormalities in the lung fields
• Cardiac MRI: Provides detailed images of the heart and major blood vessels

Treatment

Treatment of tetralogy of Fallot usually involves surgical interventions:

Complete intracardiac repair

The most common surgery, usually performed in infancy, involves closing the VSD and repairing the narrowed pulmonary artery. The procedure usually involves:

• Closure of the VSD: Using a synthetic patch to seal the hole between the heart’s lower chambers
• Relief of pulmonary stenosis: Repairing or replacing the narrowed pulmonary valve and widening the pulmonary artery to improve blood flow to the lungs
• Redirecting the aorta: Ensuring the aorta is correctly positioned over the left ventricle

Temporary or palliative surgery, such as a shunt operation, may be an option to improve blood flow until a more definitive surgery can be performed.

Medications

While surgeries are the primary treatment, medications may be prescribed to manage symptoms before and after surgery. These may include drugs to control heart rhythm, improve heart function, or alleviate fluid buildup.

Potential complications

Complications from tetralogy of Fallot and its treatments might include:

• Irregular heartbeats (arrhythmias)
• Leaking heart valves
• Residual VSD
• Heart failure
• The need for further operations or catheter-based interventions later in life

Living with tetralogy of Fallot

Living with tetralogy of Fallot requires ongoing medical care, but with advances in medical technology and surgical techniques, individuals with tetralogy of Fallot can lead full and active lives.