Tetralogy of Fallot
Tetralogy of Fallot is a problem with a heart’s structure that changes the normal flow of blood through the heart. Tetralogy of Fallot is a rare and complex heart defect and occurs in about 5 of every 10,000 babies. Doctors are not certain what causes tetralogy of Fallot.
Tetralogy of Fallot involves 4 heart defects:
- Ventricular septal defect (VSD): An abnormal opening between the two lower chambers of the heart
- Pulmonic stenosis (PS) : A narrowed area within the main pulmonary artery, at, above or below the pulmonary valve
- Malpositioned or overriding aorta: The entrance to the aorta overrides the VSD
- Ventricular hypertrophy: An overly muscular right ventricle
In a typical heart, oxygen-poor blood flows to the right side of the heart where it is pumped to the lungs to receive more oxygen. In tetralogy of Fallot, the pulmonic stenosis makes it harder for the blood to flow out of the right side of the heart. This can cause elevation of right-sided heart pressures that may result in oxygen-poor blood being moved across heart to the left ventricle and into the aorta.
When the aorta carries “mixed” blood to rest of the body, less oxygen is available to the tissues, causing cyanosis – the appearance of a blue or purple coloration of the skin or mucous membranes, sometimes called “blue baby syndrome”.
Patients can be seen by Texas Children's experts in Heart Center.
Diagnosis & Tests
Your child's doctor may recommend several tests to diagnose tetralogy of Fallot. These tests can provide information about the 4 heart defects that can occur and how serious they are. Tests may include:
- Chest x-ray
- Complete blood count (CBC)
- Electrocardiogram (EKG)
- Cardiac catheterization
Treatment & Care
Open-heart surgery, either soon after birth or later in infancy, is the most successful treatment. At Texas Children’s Heart Center, a surgical approach to the repair of tetralogy of Fallot is individualized for each patient based on age, anatomy and symptoms. This allows us to repair the defect and preserve critical parts of the cardiac anatomy, thereby optimizing the patient’s cardiac function over the long-term.
Based on our team’s assessment, surgery can be undertaken in 1 or 2 stages:
- First stage: Blalock-Taussig shunt: An artificial shunt (or tube) is placed between the aorta and pulmonary artery to increase blood flow to the lungs.
- First or second stage: Complete tetralogy of Fallot repair. The opening between the 2 chambers of the heart is patched to prevent right-to-left shunt and the right ventricular outflow tract is widened to increase blood flow to lungs.