DEAR MAYO CLINIC: My new grandson has tetralogy of Fallot. Can you explain the condition and treatment? Can I expect him to live a normal life?

ANSWER: Tetralogy of Fallot is a congenital heart disease that affects the structure of the heart. This abnormality occurs during development. It is not related to anything that a child’s mom did or took during pregnancy, and it is not inherited or linked to a specific gene. Tetralogy of Fallot causes oxygen-poor blood to flow out of the heart and to the rest of the body, often resulting in babies having blue-tinged skin because their blood doesn’t carry enough oxygen.

The syndrome is named for French physician Etienne-Louis Arthur Fallot, M.D., who first published a description of the defect in 1888. This anomaly was central to the development of cardiac surgery to treat congenital heart defects. Doctors at Johns Hopkins were the first to devise a procedure to place a shunt to bypass cardiac defects related to tetralogy of Fallot and redirect unoxygenated blood directly to the lungs. The first corrective surgery to repair the heart defect was performed in 1954 at the University of Minnesota.

The term “tetralogy” refers to the four main features of the anomaly, but it is actually due to a single defect. The septum, which separates the left and right ventricles of the heart, is not aligned correctly. This results in a hole between the left and right ventricles, called a ventricular septal defect, and narrowing of the pulmonary artery the vessel that provides blood flow to the lungs. It also can cause a deformity in the pulmonary valve in some babies.

In most cases, if there isn’t enough blood getting to the lungs, when a baby is born, he or she will be blue because the oxygen saturation is low. There are tetralogy babies who have sufficient blood flow to the lungs, and these babies are commonly termed “pink tets.” While they have adequate oxygen saturation, they have other symptoms consistent with heart failure, such as trouble eating and difficulty gaining weight.

Due to the issues caused by tetralogy of Fallot, your grandson will need heart surgery, though the timing will depend on the specifics of his situation. If oxygen saturations are adequate and he is gaining weight, surgery is generally performed at 4 to 6 months of age. During the surgery, the hole between the ventricles is closed and the blood flow to the lungs is corrected by enlarging the pulmonary artery and pulmonary valve. If doctors determine he would need intervention earlier, options include performing the full repair earlier or placing a shunt that increases blood flow to the lungs until your grandson is older and can have a full repair.

Most tetralogy of Fallot children generally do well after surgery. The blood flow to the lungs is restored, and they are no longer blue. Long term, these patients likely will need other interventions. Most people with tetralogy of Fallot will need a pulmonary valve replacement at some time in the future. The age when this becomes necessary varies, such as an older child or a young adult. Some of these pulmonary valve replacements can be performed by interventional cardiologists who go through the vessels in the groin.

While you may be anxious and concerned for your grandson, it is important to note that children who have complete operative correction at the appropriate age can go on to have a normal lifestyle and life span. Your grandson should be able to do most everything his counterparts do, including participate in competitive sports. A great example is Shaun White, an Olympic gold medalist snowboarder. He has tetralogy of Fallot.

As your grandson grows, it is important to have a pediatric congenital heart cardiologist follow him. Then he should transition to a cardiologist who specializes in providing care for adults with congenital heart disease. About half of all tetralogy of Fallot patients develop heart rhythm problems as adults, and they may need a pacemaker or defibrillator. In the meantime, enjoy your grandson and encourage him to adopt heart-healthy habits, which can only further benefit him as he grows.