Septomarginal trabecula and anterior papillary muscle in primate hearts: developmental issues

Abstract

The septomarginal trabecula is present in all human hearts as well as in thehearts of other primates. It usually connects the interventricular septum withthe anterior papillary muscle, although there are many variations in how this isachieved. The object of the analyses was to estimate the bilateral topography ofthe septomarginal trabecula and the anterior papillary muscle in the context ofthe ontogeny and phylogeny of primates. A total of 138 hearts were examinedfrom number of different non-human primates. The presence of the septomarginaltrabecula was confirmed in 94.9% of cases, although not in the hearts ofLemur varius. Four configurations could be distinguished by defining the locationof the septomarginal trabecula and its relation to the anterior papillary muscle.For the hearts of the Strepsirrhini and the majority of Platyrrhini neither structurewas related, whereas in all examined representatives of Hominoidea they hadfused and created morphologically varying forms. On the basis of these results,a concept was developed for the sequence of changes which the topography ofthe septomarginal trabecula and the anterior papillary muscle undergo duringontogeny and phylogeny.