Causes of TGA
Congenital heart defects, such as transposition of the great arteries, are the result of problems that occurred early in the heart’s development.
Although there is no direct cause for the defect, it is thought that genetics and environmental factors during the mother’s pregnancy may play a role, including:
- Mother who is over 40 years old
- Family history of TGA or other congenital heart defects
- Poor nutrition during pregnancy
- Rubella (German measles) or other viral illnesses during pregnancy
- Poorly controlled diabetes during pregnancy
TGA also is associated with chromosome disorders, such as Down syndrome.
Diagnosis and Treatment Options
TGA usually is diagnosed based on the above signs and symptoms, a physical exam, and the results from tests and procedures.
During a physical exam, your doctor will listen to your baby’s heart and lungs to check for a murmur and will evaluate your baby’s general appearance to look for signs of a heart defect, such as a bluish tint to the skin, lips, or fingernails and rapid breathing.
TGA is one of the critical congenital heart defects that can be detected on pulse oximetry. Pulse oximetrey is a simple, non-invasive, bedside test to determine the amount of oxygen in the baby’s blood.
If your doctor finds any signs of TGA, your baby likely will undergo additional testing. Additional tests that your doctor may order include a chest x-ray, echocardiogram (echo), electrocardiogram (EKG), or cardiac catheterization. For more information on these tests, visit our common diagnostic tests page.
The only treatment for TGA is open heart surgery, which is performed by a pediatric/congenital heart surgeon (cardiothoracic surgeon).
Be sure to speak with your baby’s doctor about what you should expect during and after the surgery. You can print these sample questions to use as a basis for discussion with the doctor.
Expected outcomes: The Society of Thoracic Surgeons (STS) Congenital Heart Surgery Database shows an expected outcome of 1.9% mortality for arterial switch operation for isolated transposition of the great arteries. Mortality is higher when there are additional defects like a hole in the heart (VSD) or narrowing of the arteries to the body (aorta). Outcomes will vary across different programs. It is appropriate to inquire about the outcomes of a surgical group or surgeon during your consultation.
Surgery often is performed in the first weeks of life, and the most common approach is the arterial switch procedure. During the procedure, the great arteries are cut off the heart just above the associated valve and then are switched to their usual position. The coronary arteries also are moved and reattached to the new aorta so that the heart is supplied with oxygenated blood. If any septal defects are present, they are closed during the same surgery.
Expected hospital stay after the arterial switch operation is approximately 2 weeks. This can vary depending on how sick the baby is prior to surgery, time to full feeds postoperatively, and any other issues that may delay discharge.
After surgery, your baby will require continued follow-up care. The doctor will schedule routine checkups to make sure that the procedure was successful and monitor for any new problems. Most children with successful complete repair will not have any activity restrictions as they grow older.
Most children who undergo the arterial switch operation do not need any additional surgery, but sometimes patients who had an operation to repair TGA in infancy need additional surgery as they age.
Most often, this procedure is undertaken to repair or replace leaky heart valves, open up areas of narrowing, abnormal heart rhythm, and address problems with the arteries that supply the heart with blood (coronary arteries).
Illustration by Steven P. Goldberg, MD
Preventive antibiotics are almost always recommended for people who have artificial valves or who’ve had repair with prosthetic material. Be sure to ask your doctor about what is right for your child.
Reviewed by: Lauren C. Kane, MD