_:vb50950132 . _:vb50950132 . _:vb50950132 "A mitral valve disease that is characterized by the narrowing of the orifice of the mitral valve of the heart."^^ . _:vb50950132 . _:vb50950132 . _:vb50950132 "url:http://en.wikipedia.org/wiki/Mitral_valve_stenosis"^^ . _:vb50950132 .