Tetralogy of Fallot: Introduction
Tetralogy of Fallot (“TOF” or “TET”) is the most common form of cyanotic congenital heart disease. It is a complex condition of several congenital (present at birth) defects that occur due to abnormal development of the fetal heart during the first 8 weeks of pregnancy.
Tetralogy of Fallot makes up about 5 to 7 percent of all cases of congenital heart defects and occurs equally in boys and in girls. If infants with tetralogy of fallot are not treated, the symptoms usually become progressively more severe. Blood flow to the lungs may be further decreased and severe cyanosis may cause life-threatening complications.
The exact cause of tetralogy of Fallot is not known but it has been linked to occur due to a genetic defect, a chromosomal abnormality, or environmental exposure. Predisposing factors has also been identified such as maternal abuse of alcohol during pregnancy leading to fetal alcohol syndrome (FAS) that is linked with TOF, mothers who take medications to control seizures and mothers with phenylketonuria (PKU).
