Abnormal mitral valve morphology Double orifice mitral valve 2012-04-08T08:29:48Z In about 50% of Double orifice mitral valve (DOMV) cases, valvular function is normal, others present with stenosis or regurgitation. In most cases, a larger orifice is accompanied by a small eccentric accessory orifice, and some show duplicated mitral valves. Embryologically, the lesion results from abnormal leaflet fusion and persistence of the left part of the common atrio-ventricular canal. UMLS:C0344770 HP:0011568 The left atrio-ventricular connection consists of two anatomically distinct orifices separated by accessory fibrous tissue. SNOMEDCT_US:253402005