Tetralogy of Fallot is a condition of several congenital defects that occur when the heart does not develop normally. “Tetra”
is the Greek word for 4, meaning that the condition involves 4 defects, although it is primarily influenced by 2 major defects.
It accounts for 3.5% to 9% of heart defects.
| Tetralogy of Fallot |
|
|
|
| A hole in the lower chambers of the heart allows oxygenated blood to mix with deoxygenated blood, so the body receives less
oxygen than normal. A narrowed pulmonary valve also prevents a normal amount of blood from getting into the pulmonary arteries,
so the lungs receive less deoxygenated blood than normal. There may also be a thickened right ventricle wall and an aorta
that partially covers the ventricular septal defect.
|
|
This condition involves a ventricular septal defect and pulmonary stenosis. The pulmonary valve may also be small. The other
2 components are a thickened right ventricle wall and an aorta that is shifted towards the right side of the heart, over the
ventricular septal defect. There is sometimes a patent ductus arteriosus through which blood flows from the aorta to the pulmonary
arteries.
What are the symptoms of Tetralogy of Fallot?
Symptoms include a murmur. Sometimes, children experience a blue spell. TOF is diagnosed by way of a chest X-ray, an electrocardiogram,
and an echocardiogram. Rarely, cardiac catheterization may be needed to confirm the anatomy prior to surgery.
How is Tetralogy of Fallot treated?
If the baby has had a blue spell, medications can help prevent further spells. Surgery will be needed, though not usually
right after birth. This may involve putting in a shunt to help blood flow through the pulmonary arteries and closing the ventricular
septal defect, or a complete repair.
What are the outcomes of treatment for children with Tetralogy of Fallot?
Repair of this defect is usually very successful. There may, however, in some cases be a leaky pulmonary valve, which can
take its toll on the right ventricle, perhaps requiring a valve replacement. Also, the pulmonary valve can in some cases narrow
over time, requiring more surgery. Heart rhythm problems (arrhythmias) are also a potential risk.
