_:vb50952651 "A heart disease involving one or more of the four valves of the heart (the aortic and mitral valves on the left and the pulmonary and tricuspid valves on the right)."^^ . _:vb50952651 "url:http://en.wikipedia.org/wiki/Heart_valve_disease"^^ . _:vb50952651 . _:vb50952651 . _:vb50952651 . _:vb50952651 . _:vb50952651 .