A case of common truncus arteriosus with rare cardiac abnormalities.

Truncus arteriosus communis is a well-known, congenital, cardiac abnormality. In this report, we describe a very rare variant in which the truncus arose from the right ventricle, the atrial and ventricular septa were intact, the left ventricle was hypoplastic and the small right atrium was draining to the truncus arteriosus through a fibrose tunnel-like connection.