Truncus arteriosus associated with mitral atresia and a hypoplastic left ventricle.

The association of truncus arteriosus with congenital left heart abnormalities is rare. We describe a case of truncus arteriosus associated with mitral atresia and a hypoplastic left ventricle. In 11 other patients diagnosed with truncus arteriosus, none had left heart hypoplasia. Despite the truncal root being primarily or entirely committed to the right ventricle, more right than left heart abnormalities have been found. This is in contrast to double-outlet right ventricle in which left heart abnormalities are more often associated.