atrioventricular septal defect partial atrioventricular septal defect 2010-09-27T03:18:02Z partial common atrioventricular canal partial AVSD csmith partial ECD partial endocardial cushion defect a type of atrioventricular septal defect in which the endocardial cushion defects present have an interatrial communication but lack an interventricular communication; the mitral and tricuspid annuli are separate but one or more additional features are present, including primum atrial septal defect (ASD), inlet ventricular septal defect (VSD), cleft of the anterior mitral valve leaflet, and wide anteroseptal tricuspid valve commissure or cleft septal tricuspid leaflet MPheno.ontology MP:0010414 partial AVC partial atrioventricular canal defect