Transposition of the Great Arteries

Transposition of the great arteries (TGA), also referred to as dextro-transposition of the great arteries or D-TGA, is a congenital heart defect in which the two major vessels that carry blood away from the heart — the aorta and the pulmonary artery — are switched. It is a relatively rare condition, affecting 20 to 30 infants per 100,000 live births.

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What is transposition of the great arteries?

In babies with TGA, oxygen-poor blood from the body enters the right side of the heart; however, rather than traveling to the lungs, the blood is pumped directly back out to the rest of the body through the aorta. Oxygen-rich blood from the lungs entering the heart is pumped straight back to the lungs through the main pulmonary artery.

TGA is considered a critical congenital heart defect because a baby with this defect may need surgery or other procedures soon after birth. It’s common for babies with TGA to have other heart defects, such as a hole between the heart’s lower or upper chambers.

The causes of TGA in most babies are unknown. It may have to do with changes in their genes or chromosomes. Heart defects are also thought to be caused by a combination of genes and what the mother comes into contact with in her environment, such as exposure to medications during pregnancy.

Symptoms of transposition of the great arteries?

TGA symptoms occur at birth or soon after. Babies with TGA may have a condition called cyanosis, which is bluish looking skin caused by their blood not carrying enough oxygen. Other symptoms may include the following:

  • Problems breathing
  • Pounding heart
  • Weak pulse
  • Trouble eating

Care for transposition of the great arteries at Rush


If these symptoms are present, your child's physician will most likely request an echocardiogram, which is an ultrasound of the heart and the most common test used to confirm diagnosis. TGA can also be suspected with a newborn pulse oximetry screening — a simple test to determine the amount of oxygen in a baby’s blood.

The condition can also be diagnosed before birth with a test called fetal echocardiogram. This is done in the following instances:

  • The pregnant mother has risk factors for suspecting a heart anomaly in the fetus, such as exposure to alcohol, diabetes or a family history of congenital heart defects
  • There is a suspicion that the fetus has a heart abnormality on obstetrical ultrasound screening


All babies born with TGA must have surgery to switch and reattach the aorta and pulmonary arteries and reconnect the coronary arteries. Other procedures may be done before surgery to maintain, enlarge or create openings that will allow oxygen-rich blood to get out to the body.

Your baby’s chances of surviving this surgery are very high. After surgery, your baby may need the following:

  • Medications to help the heart pump better, control blood pressure, help expel extra fluid in the body, and slow the heart if it is beating too fast.
  • A pacemaker if the heart is beating too slowly.

People born with TGA have lifelong complications. Your child will need regular follow-up visits with a cardiologist to monitor their progress and avoid other health problems or complications.