Tetralogy of Fallot is a rare congenital heart defect that affects approximately 400 out of every million live births. This condition causes mixing of oxygen-poor blood with oxygen-rich blood, resulting in less oxygen being delivered to the body's organs and tissues. The lack of oxygen causes cyanosis, a bluish discoloration of the skin, lips, and mucous membranes.
What Causes Tetralogy of Fallot?
Tetralogy of Fallot occurs during fetal development, before birth. The exact cause is unknown, but it is believed to be due to an error in the formation of the heart's chambers, valves, and other structures. This congenital heart defect is not caused by anything the mother did or did not do during pregnancy.
Symptoms of Tetralogy of Fallot
Most infants with Tetralogy of Fallot develop symptoms within the first year of life, including:
Cyanosis (bluish discoloration of skin, lips, and mucous membranes)
Slow growth and development
Fatigue and rapid breathing with exertion
Squatting position to catch breath
Episodes of extreme blue coloring (tet spells)

Diagnosing Tetralogy of Fallot
If your child shows signs of cyanosis, breathing difficulties, or other symptoms, seek medical attention immediately. Your child's healthcare provider will perform various tests to diagnose Tetralogy of Fallot, including:
Blood tests to check for elevated red blood cell count and hemoglobin
Electrocardiogram (ECG) to assess the heart's electrical activity
Chest X-ray to look for a "boot-shaped heart" and abnormal aorta
Echocardiography to visualize the heart's structure and defects
Cardiac catheterization (if needed) to confirm the diagnosis
Treatment Options for Tetralogy of Fallot
Surgery is the primary treatment for Tetralogy of Fallot. The type and timing of surgery depend on the child's symptoms and the severity of the defect. Treatment options include:
Medication for managing tet spells
Knee-to-chest position during tet spells to increase blood flow to the lungs
Oxygen therapy to increase the amount of oxygen in the blood
Blalock-Taussig operation (palliative procedure) to increase blood flow to the lungs
Total correction surgery to close the ventricular septal defect and relieve pulmonary stenosis
Life After Surgery
After successful surgical correction, most children with Tetralogy of Fallot lead normal lives with few restrictions. However, long-term complications may include right ventricular failure, electrical conduction abnormalities, arrhythmias, and residual holes in the ventricular septum. Regular follow-up visits with a cardiologist are essential to monitor for these potential complications.
For more information and support, visit the American Heart Association, Centers for Disease Control and Prevention (CDC), or consult with your child's healthcare provider.