Transposition of the Great Arteries (TGA)

The specialized heart doctors at UT Southwestern Medical Center expertly diagnose and treat people with transposition of the great arteries (TGA).

Combining skill and experience with the newest science-based tools and techniques, our cardiologists and cardiothoracic surgeons can precisely evaluate and effectively treat this common congenital heart defect.

Expert Care for a Complex Heart Abnormality

Transposition of the great arteries is the most common cyanotic (low blood oxygen) congenital heart condition.

Normally, the pulmonary artery comes from the right ventricle to pump deoxygenated blood to the lungs to get oxygen, while the aorta comes from the left ventricle to pump oxygenated blood from the lungs to the rest of the body.

In patients with TGA, these “great arteries” are switched. The aorta comes from the right ventricle and pumps deoxygenated blood to the body, while the pulmonary artery comes from the left ventricle and pumps deoxygenated and oxygenated blood to the lungs.

To survive without treatment, patients must have an additional heart defect that allows the heart’s right and left sides to communicate so that blood can mix. This defect can be an atrial septal defect, ventricular septal defect, or a patent ductus arteriosus.

As with most congenital heart defects, the cause of TGA is unknown. Occurring primarily in males, the condition has a 90 percent mortality rate within the first year of life, if left untreated.

UT Southwestern’s specialized heart doctors expertly diagnose and treat transposition of the great arteries. Our experienced cardiologists and cardiothoracic surgeons offer the most advanced treatments and technologies, personalized for each patient’s unique condition.

UT Southwestern is also home to a dedicated Cardiac Rehabilitation Program. Cardiac rehabilitation is a critical component of recovery and can prevent future heart disease.

Symptoms of Transposition of the Great Arteries (TGA)

Cyanosis – a bluish color to the skin caused by insufficient oxygenation – is the primary symptom of TGA, and it is usually noticeable at birth or shortly thereafter. Its severity depends on the size and type of any heart abnormalities and how much oxygen is moving through the patient’s body:

• TGA with no additional heart defect: Severe cyanosis in the first 24 hours of life
  
• TGA with a large ventricular septal defect (VSD): Mild cyanosis when crying, increased breathing and heart rates, sweating, and failure to gain weight in the first six weeks of life
  
• TGA with VSD and obstruction in the left ventricle: Extreme cyanosis at birth
  
• TGA with VSD and pulmonary artery obstruction: Progressive cyanosis from birth
  

Diagnosing TGA

UT Southwestern cardiologists might perform several tests to diagnose TGA. Common diagnostic tests include:

• Physical exam: Determines whether the patient’s mouth and skin are blue or if a heart murmur can be heard with a stethoscope
  
• Echocardiography: A noninvasive imaging test that shows the TGA and sometimes other heart defects
  
• Cardiac catheterization: Usually performed in infants whose echocardiograms don’t provide enough information about the heart’s anatomy
• Hyperoxia test: Shows oxygen saturation in blood
  

Treatments for TGA

Treatments for transposition of the great arteries include:

• Arterial switch surgery: Corrects the defect by detaching the pulmonary artery and aorta from the wrong ventricles and attaching them to the correct ventricles, enabling the heart to receive proper blood flow
  
• Balloon septostomy: Increases the size of the hole between the right and left atria to enable more mixing of oxygenated and deoxygenated blood
  
• Intravenous prostaglandin E1 therapy: Helps the patent ductus arteriosus stay open and enables more mixing of oxygenated and deoxygenated blood
  

Support Services

UT Southwestern’s cardiac rehabilitation specialists create customized plans that integrate proper nutrition, exercise, and, if necessary, nicotine cessation into patients’ lifestyles to improve their cardiovascular health.

Clinical Trials

Clinical trials often give patients access to leading-edge treatments that are not yet widely available. Eligible patients who choose to participate in one of UT Southwestern’s clinical trials might receive treatments years before they are available to the public.