L-Transposition of the Great Arteries



Several options exist if surgery is needed. The wall between the ventricles (ventricular septal defect (VSD) can be closed with a patch, but this leaves the “wrong” ventricles connected to their respective great arteries. Ebstein’s anomaly can sometimes be repaired but may require valve replacement.

Some patients undergo a surgery called a “double switch”; two operations are performed at the same time. The first part of the operation is an atrial switch. There are two names for this surgery depending on how the surgeon performs it, either a Mustard or a Senning procedure. The operation reroutes blood from the right atrium to flow to the right ventricle and blood from the left atrium to flow to the left ventricle.

The second part of this operation is an arterial switch. This involves disconnecting the pulmonary artery and the aorta, switching them, and sewing them back to their proper ventricle. In this manner, blood from the right ventricle goes to the pulmonary artery, and blood from the left ventricle goes to the aorta. Additionally, the coronary arteries must be reconnected to the vessel that becomes the aorta.

Follow-up care into adulthood

If you were treated as a child and are now an adult

Adults who underwent surgery as children have many of the same long-term problems as those diagnosed in adulthood. The risk of complete heart block is higher in those who have had surgery. Patients with only VSD patch closure or Ebstein’s anomaly repair still use their right ventricle to pump blood to their bodies. This requires close monitoring for symptoms of congestive heart failure.

Patients who have undergone a “double switch” require follow-up to monitor the area where the blood is rerouted between the two atria to make sure it remains wide open without narrowing. Also, the area in the pulmonary artery and the aorta where the surgeon had to cut the blood vessels to move them to the correct ventricle can become narrowed. Coronary artery problems can also occur when they were reimplanted. Many of these issues can be treated with a balloon catheter or stent.

If you’re diagnosed in adulthood

Some patients are diagnosed with L-TGA for the first time in adulthood. These adults typically don’t have other associated defects such as VSD or Ebstein’s anomaly. However, there are other issues that require long-term follow-up with a cardiologist who specializes in CHD. Heart failure can occur because the right ventricle is not usually equipped to pump blood to the body for several decades. Also, backflow of blood through the tricuspid valve connected to the right ventricle is common and can lead to congestive heart failure. Your cardiologist may prescribe medicines to help alleviate some of these symptoms. Some valves may be damaged so severely that they’ll require surgery for valve repair or valve replacement.

Heart rhythm abnormalities are also common in patients with L-TGA. The most common of these is a complete heart block, which results in slowing of the heart rate. These patients require a pacemaker to treat the abnormal heart rate.