abnormal interventricular septum membranous part morphology interventricular septum membranous part aneurysm 2010-09-27T03:54:46Z Fyler:2346 MP:0010416 MPheno.ontology a a saclike thinning, stretching and widening of the ventricular membranous septum resulting from weakening of the membraneous septum wall aneurysm of membranous septum csmith ventricular membranous septum aneurysm ventricular aneurysm