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