Further morphological observations on hearts with twisted atrioventricular connections (criss-cross hearts).

A superior and anterior location of the tricuspid valve in the setting of malalignment between the atrial and ventricular septal structures was the characteristic unifying morphologic feature of seven autopsied hearts with twisted atrioventricular connections. The peculiar angiocardiographic appearances of this lesion could be readily explained by the findings of unusual recesses in the right atrium, in the right ventricle, and in the left ventricle. The recess in the morphologically left ventricle was seen in each case at the right posterior part (or, in the hearts with left-handed ventricles, at the left part) of the chamber. Displacement of the right-sided atrioventricular valve far from the inferior caval vein (vena cava) had produced the recess in the morphologically right atrium; this feature was most prominent in the heart in which the atrioventricular connections were discordant. The recess within the right ventricular outflow tract was seen in four hearts, in all of which the inlet and apical trabecular components of the right ventricle were hypoplastic.