Tetralogy of Fallot

Tetralogy of Fallot is a common cyanotic (“blue baby”) congenital heart defect characterized by a combination of four specific heart abnormalities:

  • Pulmonary Stenosis: This is a narrowing or obstruction of the pulmonary valve or the blood vessels that connect the right ventricle to the pulmonary artery, reducing the flow of blood to the lungs. 
  • Ventricular Septal Defect (VSD): This is a hole in the wall (septum) that separates the two lower chambers of the heart (the ventricles). The VSD allows oxygen-poor blood from the right ventricle to mix with oxygen-rich blood from the left ventricle.
  • Overriding Aorta: In Tetralogy of Fallot, the aorta, which carries oxygen-rich blood to the body, is shifted slightly to the right and overrides both ventricles instead of originating exclusively from the left ventricle.
  • Right Ventricular Hypertrophy: The right ventricle is usually thicker and more muscular than normal because it must work harder to pump blood to the lungs due to the pulmonary stenosis.

Most if not all tetralogy of fallot patients have had prior surgical and/or interventional procedures in childhood.  However, commonly they have residual problems (ie. pulmonary insufficiency, arrhythmia, heart failure) that need lifelong ACHD follow-up. 

 

Symptoms

The severity of symptoms in individuals with Tetralogy of Fallot can vary. Common symptoms may include:

  • Shortness of breath, especially during physical activity.
  • Fatigue and weakness.
  • Rapid heart rate or syncope.
  • Heart failure

 

Diagnosis

Tetralogy of Fallot need routine diagnostic testing and follow-up. Diagnostic tests may include:

    • Echocardiography (echo): This ultrasound test provides detailed images of the heart and is the primary tool for diagnosing Tetralogy of Fallot.
    • Electrocardiogram (ECG or EKG): This test records the electrical activity of the heart and may show signs of right ventricular hypertrophy.
    • Cardiac MRI or CT scan: These imaging tests can provide additional information about the heart’s anatomy and function.
    • Cardiac catheterization and EP studies.

 

Treatment

Depending on the residual defects and related complications, different treatment strategies are available.  They may include the following:

      1. Surgical pulmonary valve replacement.
      2. Transcatheter pulmonary valve replacement
      3. Electrophysiological procedures to treat heart rhythm abnormalities. 

 

When to consult a physician

Tetralogy of Fallot patients should be monitored life long, even without symptoms.