abnormal cardiovascular development abnormal cardiac epithelial to mesenchymal transition anomaly in the process by which endocardial cells of the atrioventricular canal or the outflow tract lose their epithelial characteristics, delaminate from the endocardial sheet, become migratory and invade the cardiac jelly, and develop mesenchymal characteristics eventually forming both the endocardial cushions required for septum and atrioventricular valve formation and the cushions of the outflow tract that form the conotruncal septum abnormal endocardial-mesenchymal transformation abnormal cardiac epithelial to mesenchymal transformation MP:0008825 MPheno.ontology