The Congenital Heart Program, Albany Medical Center Figure 1. Notice VSD and single Truncal Vessel. Notice aorta and pulmonary artery arise from truncal vessel.
Arrows indicate direction of blood flow.
In truncus arteriosus only one single artery arises from the heart. There are three types of truncus arteriosus depending on how exactly the pulmonary arteries come off the truncal vessel. The valve between the ventricles and the truncal vessel, the truncal valve, is usually abnormal. Mild truncal stenosis and insufficiency are usually well tolerated. In truncus arteriosus there is usually excessive blood flow through the pulmonary arteries to the lungs.