Tetralogy of Fallot is a complex heart defect that is present at birth (a congenital heart disease). It accounts for about 9 to 14 percent of all congenital heart defects in the United States, according to the American Heart Association. A tetralogy is a complex of four conditions. Tetralogy of Fallot involves four specific heart defects.

These four heart defects lead to a reduced blood flow to the lungs and the mixing of oxygen-rich and oxygen-poor blood in the heart. Together, these defects mean that the body does not receive enough oxygen-rich blood. Thus, the child’s skin, lips, fingernails and tongue often have a bluish tint (cyanosis, or blue baby when occurring in infants). This tint is especially noticeable after exertion (which for babies is most often during feeding time). If it is not corrected, tetralogy of Fallot tends to lead to death before the age of 20.

Physicians have developed ways to treat and approach tetralogy of Fallot, including surgery. Surgery to correct tetralogy of Fallot may be performed any time from infancy to 5 years old, depending on how severe the problem is. Sometimes two surgeries are performed: one to relieve symptoms by increasing the blood flow to the lungs (palliative), and one to correct the underlying defects (reparative).