How Best Can We Define Double Outlet Right Ventricle When Describing Congenitally Malformed Hearts?

The Eisenmenger malformation: a morphologic study

“…14 Another of us, however, had disputed the significance of this finding when considering the arrangements in which both arterial trunks arise predominantly from the right ventricle. 15 Therefore, to adjudicate these previous differences, and hopefully to elucidate the nosological significance of its phenotypic features, we have now carried out a detailed analysis of the subpulmonary infundibular morphology of the hearts catalogued as having the Eisenmenger defect in the archive of the University of Rome. We have compared these findings with those from a comparable number of specimens with intact ventricular structures, and others with perimembranous ventricular septal defects in the absence of overriding of the aortic root.…”

“…, 13 In this regard, one of us had suggested that the similarity between the Eisenmenger defect and tetralogy of Fallot reflected the biventricular origin of the overriding aorta, but that the differences relate to the degree of expansion of the subpulmonary infundibulum 14 . Another of us, however, had disputed the significance of this finding when considering the arrangements in which both arterial trunks arise predominantly from the right ventricle 15 . Therefore, to adjudicate these previous differences, and hopefully to elucidate the nosological significance of its phenotypic features, we have now carried out a detailed analysis of the subpulmonary infundibular morphology of the hearts catalogued as having the Eisenmenger defect in the archive of the University of Rome.…”

What is aortic overriding?

“…All of these aspects have been contentious in the past, and some continue to be so. 1,2,4,5 Use of the definitions as proposed in our review provides simple resolutions to these various disagreements. Perhaps most importantly, concentration on the degree of connection of the overriding root as revealed by CT analysis in the short axis provides a simple and rigorous means of defining double outlet right ventricle (Fig 15), and distinguishing this entity from the hearts with concordant or discordant ventriculo-arterial connections (Figs 10, 12, and 16).…”

“…23 The existence of these hearts (Figs 18 and 19) is further evidence that double outlet right ventricle is not a phenotype, but rather one form of ventriculo-arterial connection. 5 Furthermore, they show that bilateral infundibulums are not an essential part of the diagnosis, although they certainly can, and do, exist in this setting (Fig 18). Recognition of these facts facilitates the understanding of the spectrums seen in the setting of overriding arterial trunks.…”

“…2 An added value of using the concept of overriding according to the biventricular connection of the aortic valve is that, as we will show, it now provides a reproducible means of distinguishing between double outlet and concordant ventriculo-arterial connections, another topic of potential contention. 4,5 When discussing the potential distinction of "true" as opposed to "false" dextroposition, the Turkish authors had also suggested that "new diagnostic modalities" are required for "proper planning of treatment". 3 In this review, we will show that such modalities already exist.…”