Conotruncal Heart Defect
Conotruncal heart defects are also known as outflow tract defects. Conotruncal heart defects are believed to make up a fifth of all congenital heart defects detected before birth. The most common conotruncal heart defects include:
- Truncus Arteriosus (also known as Common Truncus)
- Transposition of the Great Arteries
- Double Outlet of the Right Ventricle
- Tetralogy of Fallot
Conotruncal heart defects are thought to result from either a disturbance of the outflow tract of the embryonic heart, or impaired development of the branchial arch and arteries, or both.
- Truncus Arteriosus (Common Truncus): Truncus Arteriosus is a heart birth defect that occurs when the aorta and the pulmonary artery are together in one blood vessel. A baby with truncus arteriosus usually begins to have problems in the first week of life. Their oxygen levels are often slightly lower than normal resulting in cyanosis. Because of the excessive amount of blood flow to the lungs with this defect, congestive heart failure develops in the first weeks of life. Truncus arteriosus is commonly found in addition to ventricular septal defect. Open-heart surgery is needed to correct this issue and to install a prosthetic tube that will direct blood flow correctly.
- Transposition of the Great Arteries: Transposition of the great arteries is a rare heart defect present at birth, in which the two main arteries leaving the heart are reversed. This changes the way blood circulates through the body, leaving a shortage of oxygen in blood flowing from the heart to the rest of the body. Corrective surgery soon after birth is the usual treatment for transposition of the great arteries.
- Double Outlet of the Right Ventricle (DORV): With a DORV, the pulmonary artery and the aorta—the heart’s two great arteries—both arise from the right ventricle. Normally, the pulmonary artery that carries blood to the lungs to receive oxygen arises from the right ventricle. And the aorta, which carries oxygenated blood from the heart to the body, arises from the left ventricle. Most cases of DORV defects are accompanied by other defects, such as ventricular septal defect. Serious, invasive surgery is required to correct DORV.
- Tetralogy of Fallot: Tetralogy of Fallot actually consists of a combination of four heart defects that are present at birth. In many cases, multiple surgeries will eventually correct all of the defects. But in the most severe cases, a heart transplant may be the only option.