Atresia of the left atrioventricular orifice associated with a Holmes heart.

The first well-documented case of Holmes heart associated with an atretic left atrioventricular orifice is reported. The Holmes heart may be considered as a single ventricle in which the main chamber has the morphologic characteristics of a left ventricle, the infundibular chamber is not inverted, and the great arteries are normally arranged. The importance of this report is greater than its simple description since it definitely establishes the coexistence of a true single ventricle and atresia of the atrioventricular orifice is possible.