Tetralogy of Fallot (TOF) is a congenital heart defect that is a combination of four heart problems. It significantly affects the heart’s structure and function, leading to poor oxygenation of blood. The four abnormalities that define TOF are:
- Ventricular Septal Defect (VSD): A hole between the heart’s two lower chambers (ventricles).
- Pulmonary Stenosis: Narrowing of the pulmonary valve and outflow tract, obstructing blood flow from the right ventricle to the lungs.
- Right Ventricular Hypertrophy: Thickening of the muscular walls of the right ventricle.
- Overriding Aorta: The aorta, which usually carries oxygen-rich blood to the body, is positioned directly over the VSD, receiving blood from both the right and left ventricles.
Symptoms of TOF
- Cyanosis: A blue tint to the skin, lips, and fingernails due to low oxygen levels.
- Difficulty Feeding: Babies may struggle to feed or fail to gain weight.
- Failure to Thrive: Poor growth and development.
- Tet Spells: Episodes of deep cyanosis, trouble breathing, or fainting.
Diagnosis
- Echocardiogram: Main diagnostic tool, provides detailed images of the heart.
- Chest X-ray: Can show the heart’s shape and size, which is often altered in TOF.
- Electrocardiogram (ECG): Assesses the electrical activity of the heart and can detect right ventricular hypertrophy.
- Cardiac Catheterization: Used to assess the severity of the defect and plan for surgery.
Treatment
- Surgery: The primary treatment for TOF, usually done within the first year of life. The surgical procedure typically involves:
- Closing the VSD.
- Widening the pulmonary valve and outflow tract.
- Palliative Surgery: In some cases, a temporary surgery is performed to increase blood flow to the lungs until a full repair can be done.
- Long-term Care: Children with TOF require lifelong cardiac care, even after surgical repair.
Prognosis
- With early surgical intervention, most children with TOF grow up to lead normal or near-normal lives.
- Long-term survival rates are high, but some may require additional surgeries or interventions in adulthood.
Complications
- Residual Defects: Such as leaks in the pulmonary valve.
- Arrhythmias: Irregular heartbeats are common in later life.
- Endocarditis: Increased risk of heart infection.
Preventive Measures
- While the exact cause of TOF is unknown, good prenatal care and avoiding harmful substances during pregnancy can reduce the risk of congenital defects.
- Genetic counseling may be recommended for families with a history of TOF or other congenital heart defects.
Regular follow-up with a pediatric cardiologist is crucial for children with TOF, to monitor their heart health and manage any long-term complications.
