Surgery is the only treatment to repair this heart defect. Depending upon the severity of the defect, surgery may be performed any time between birth and the first few years of life. Also, the longer the heart muscles, tissues and vessels operate in the presence of these defects, the more long-term (even post-surgery) damage they will sustain. Although surgery used to be performed routinely in the first few years of life, the current approach in the United States is to plan on surgical correction in the first few weeks to months of life.

Once the defect is detected, surgery usually has a high success rate. Conversely, choosing not to have the surgery results in a high risk of death before age 20.

During corrective surgery, the pulmonary valve is widened to increase blood flow, and the ventricular septal defect is closed or patched in such a way that all the blood flow from the left ventricle is pumped out to the aorta. Some of the thickened muscle in the right ventricle may need to be removed to allow for the blood to be pumped from the right ventricle out to the pulmonary artery. Synthetic material may need to be inserted to enlarge narrowed areas of the right ventricle, the pulmonary valve, and the pulmonary arteries.

Sometimes a palliative surgery (to relieve symptoms temporarily but not to fix the defect) is done before the corrective surgery to fix the defect. A palliative surgery is usually performed when the child’s heart structures have not developed enough for surgery to make a full correction. Palliative surgery relieves symptoms until the child has grown enough for a corrective surgery to be done. It may also be necessary if the baby is born very prematurely and the risk of open heart surgery us too great.

Palliative surgery involves the creation of a systemic-pulmonary shunt to redirect the blood flow. A systemic-pulmonary shunt is designed to detour some of the blood from the aorta (which is getting blood from both the left and right ventricles) to the pulmonary artery (which is getting very little blood). The pulmonary artery then carries the blood to the lungs, as it does normally. This increases blood flow to the lungs, which can then supply the body with more oxygen-rich blood and reduce the child’s bluish skin tone (cyanosis). A number of types of shunts (e.g., a Blalock-Taussig shunt) may be used for this type of palliative surgery. 

Before any type of surgery, there are immediate ways to relieve some symptoms, including:

According to the American Heart Association, patients who have undergone surgical repair of tetralogy Fallot can also expect:

• Possible restrictions on some physical activity such as certain competitive sports, as recommended by their cardiologist.
  
  
• A possible eventual decline in functioning of heart muscle, necessitating medications such as diuretics or other antihypertensives.
  
  
• An increased risk of abnormal heart rhythms (arrhythmias), which can cause dizziness or fainting (syncope) and may require medication or surgery.
  
  
• A possible increased risk of a difficult pregnancy in some women who were born with tetralogy of Fallot. There is also an increased risk of giving birth to a child with tetralogy of Fallot if a parent was born with it.
  
  
• Further surgery to insert an artificial or replacement pulmonary valve, replace or repair the pulmonary artery, or enlarge the attachments to the pulmonary arteries supplying the right and left lungs.
  
  
• Probable need for special education and care services if there are other birth defects.

Tetralogy of Fallot, like almost all forms of congenital heart disease, will require the patients to be evaluated on a regular basis by cardiologists familiar with congenital heart disease for their entire life. However, research has shown that many adults with congenital heart defects such as tetralogy of Fallot do not receive regular cardiac care. The U.S. National Institutes of Health (NIH) is considering requests from cardiologists to establish a national registry of such patients to improve care.