Double inlet right ventricle. Two pathological specimens with comments on embryology.

This paper describes two pathological specimens of congenital heart disease with double inlet right ventricle in which the ventricular chamber receives the right atrioventricular ostium and partially the left atrioventricular ostium, the two atrioventricular ostia being completely separated. The published reports are reviewed and only cases of double inlet left ventricle have been found. An ontogenetic explanation for the malformation described, based on the study of normal human embryos, is presented. Double inlet right ventricle represents a deviation from the normal course of the development of the heart in which the process ofexpansion of the atrioventricular canalfrom left to right has been exaggerated, leading to the connexion of the left atrium with the right ventricle. Both hearts had transposition of the great vessels.