The atrioaortic, atrioventricular, and ventriculoaortic septae in the human heart

Abstract

We demonstrated in the canine heart that there are heretofore unknown septae separating regions of the right atrium and right ventricle from the aorta at the level of the right (*) and posterior aortic sinus (· PAS) and separating the right atrium from the left ventricle. Here we report the septae in the human heart in a stereotaxic study. Methods and Results Photographs of the epi- and endocardial exposure of whole and flattened hearts and during blocking (8) were compared to photographs of serial orthogonal transverse plane histologic sections stained by Goldner Trichrome (5). Every section was mounted, accessioned and initially evaluated at .5 mm intervals. In human hearts, the same structures and relationships in dog heart differed only in size and pitch. For the septae, the atrioaortic septum extends between the right atrium at the level of an aortic sinus wall; the ventriculoaortic septum (VAS) extends between the right ventricle at level of an aortic sinus wall (Figure, VAS is in the PAS); and the atrioventricular septum-membranous and -muscular components extend between the right atrium and the left ventricle. The membranous ventricular septum extends under the right and posterior aortic sinuses. Conclusions The septae separate low- from high-pressure chambers and can be at risk of breech or puncture with pathology or during cardiac procedures and help to explain rupture of the right sinus of Valsalva into the right ventricular outflow tract imaged via transesophageal echocardiograms (Cullen et al., Circulation, 2002: –e2). Support: NIH HL073261 (DKR).