TOF in medical terms stands for Tetralogy of Fallot, a congenital heart defect involving a combination of four heart abnormalities present at birth.
Understanding Tetralogy of Fallot
Tetralogy of Fallot (TOF) is a complex heart condition that affects the structure of the heart, leading to oxygen-poor blood flowing to the body. It is relatively rare, affecting approximately 1 in 2,500 babies.
The Four Key Defects in TOF
The "tetra-" in Tetralogy of Fallot refers to the four specific heart defects that occur together:
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Ventricular Septal Defect (VSD): A hole between the two lower chambers of the heart (ventricles). This allows blood to flow between the ventricles.
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Pulmonary Stenosis: A narrowing of the pulmonary valve and artery, which restricts blood flow to the lungs. This can occur at the valve itself (valvar stenosis), below the valve (subvalvar stenosis), or above the valve (supravalvar stenosis).
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Overriding Aorta: The aorta, the main artery carrying blood from the heart to the body, is positioned abnormally. It sits over both ventricles (instead of just the left ventricle) and receives blood from both.
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Right Ventricular Hypertrophy: The muscle of the right ventricle becomes thickened (hypertrophied) because it is working harder than normal to pump blood through the narrowed pulmonary artery.
Effects of TOF
These four defects together result in the following problems:
- Reduced Blood Flow to the Lungs: Pulmonary stenosis obstructs blood flow to the lungs, limiting the amount of oxygen the blood can pick up.
- Mixing of Oxygen-Rich and Oxygen-Poor Blood: The VSD and overriding aorta allow oxygen-rich blood from the left ventricle and oxygen-poor blood from the right ventricle to mix and enter the systemic circulation.
- Cyanosis: Due to the mixing of blood and reduced blood flow to the lungs, babies with TOF often have cyanosis, a bluish tint to the skin, lips, and nails, because of low oxygen levels in the blood.
Diagnosis and Treatment
TOF is typically diagnosed shortly after birth or during infancy through physical examination, echocardiogram, and other diagnostic tests. The condition usually requires surgical repair, often involving closing the VSD and relieving the pulmonary stenosis. Early diagnosis and treatment are crucial for improving the long-term health and survival of individuals with Tetralogy of Fallot.
