Tetralogy of Fallot is a congenital heart defect that involves the incorrect formation of the septum (partition) between the right and left ventricles. This condition results in mixing oxygen-rich and oxygen-poor blood across the ventricular septal defect, which causes an overall decrease in the amount of oxygen in the blood.
It is called tetralogy of Fallot because "tetralogy" means "four" in Greek and there are four defining features of this heart defect.
The four heart problems that make up tetralogy of Fallot include:
- A hole between the ventricles or the lower chambers of the heart, called a ventricular septal defect (VSD)
- A blockage or kink in the pulmonary artery where blood flows from the heart to the lungs
- The aorta, the largest blood vessel, lies over the hole (VSD) in the lower chambers of the heart
- The muscle surrounding the lower right chamber is too thick
Some patients may also have a complete blockage from the right ventricle (called pulmonary valve atresia). Pulmonary valve stenosis, or the pulmonary valve's inability to open properly, is also seen in babies with tetralogy of Fallot. This defect usually limits blood flow to the lungs, resulting in lower oxygen levels in the baby's body after birth.
What causes tetralogy of Fallot?
Tetralogy of Fallot is a congenital heart condition, meaning children are born with it. The cause of the condition is not known. In some situations, it may be associated with certain genetic syndromes like DiGeorge syndrome, also known as 22q11.2 deletion syndrome.
Children usually show symptoms of the condition and are diagnosed shortly after birth. With treatment, kids with tetralogy of Fallot can lead normal, healthy lives. However, if your child has tetralogy of Fallot, he or she will need follow-up care to monitor any changes in the heart.
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