Aberrant course of the anterior interventricular part of the great cardiac vein in the human heart.

A rarely encountered aberrant course of the great cardiac vein was found during exploration of 250 human heart specimens in 1984 to 1987. Originating in the distal anterior interventricular groove, it leaves the sulcus to the right, passes the arterial conus, and crosses the right atrioventricular groove, and empties, together with the anterior cardiac veins, into the right atrium. So the great cardiac vein is not a tributary of the coronary sinus. This atypical variant can be explained phylogenetically as the result of an unusual development of the anterior cardiac vein system. Comparative anatomy demonstrates some birds and some mammalia showing large anterior cardiac veins and anterior conus veins, which drain the right lateral and anterior wall of the heart and empty into the right atrium or the superior vena cava. Our specimen may be interpreted as a remnant and as an enlarged conus vein. There is no known previous description of such a variation.