Ventriculoarterial discordance revisited: angiographic presentation and discussion of a typical case.

This article reexamines the subject of ventriculoarterial discordance in the light of a case report and the recent literature. The angiographic method of studying complex cardiac defects is illustrated by example, in order to stress the need for a systematic, step-by-step, segmental approach to diagnosis. We favor use of the term "ventriculoarterial" discordance to refer to a defect that involves incongruence of ventricular and arterial morphologies, as predicated on the loop rule. This rule calls for anticipation of certain spatial relationships between aortic and pulmonary trunks, given certain ventricular morphologies: with a right-sided, anatomically right ventricle, for example, the ascending aorta is expected to be on the right side, whether with normally crossed or transposed great vessels (D-loop derivatives). As in the case presented here, ventriculoarterial discordance features the ascending aorta on the opposite side of the anatomically right ventricle. The influence of the formation of an abnormal cardiac apex (as in crisscrossed or superoinferior hearts) on the cardiac segments' configurations is discussed, since this too can affect the spatial relationships between the great vessels.