Congenitally corrected transposition of the great arteries (CCTGA) is a rare heart defect present at birth (congenital) where the lower chambers of the heart (ventricles) do not function properly. CCTGA accounts for less than 1% of all congenital heart defects. Normally, the right ventricle is smaller and less strong because it only has to pump blood low in oxygen to the lungs. The left ventricle is larger and stronger because it has to pump the oxygen rich blood to the whole body. In CCTGA, during development, the heart twists and the larger, stronger ventricle (normally on the left side) ends up on the right side of the heart. It receives the blood low in oxygen and is now connected to the pulmonary artery so the blood is sent to the lungs. But the smaller, weaker ventricle is now on the left, and though it pumps the oxygen rich blood into the aorta to go out to the rest of the body, it is not built to do this job for a normal lifetime. CCTGA can be found alone or with other congenital heart defects, such as VSDs, Ebstein-like valves, and heart’s electrical signals blockages.
The symptoms of CCTGA are fainting and fatigue. Some people may also have an abnormal sound in their heartbeat (heart murmur). Many do not have symptoms until adulthood. However, symptoms may vary and even infants may show signs immediately after birth. The causes of CCTGA are not yet known, but parents with CCTGA do not seem to pass the defect to their children.
The most common tests to diagnose CCTGA are an echocardiogram and a cardiac MRI. Treatments vary greatly. If CCTGA is isolated (no other heart defects), treatment may not be needed. Children now born with this condition have a much better life expectancy than previous generations but will still need to see a cardiologist throughout their lifetime. Research is ongoing, so talk to your cardiologist about the current treatment options. Support groups are also a good source of information and support.