Denis Bouchard MD, Michel Pellerin MD, Raymond Cartier MD, Michel Carrier MD, Louis P Perrault MD, Yves Hebert MD.The morphologic characteristics of rheumatic mitral valve disease operated in Canada are chronic fibrosis of the leaflets and subvalvular apparatus, often associated with annular calcifications.The first line of treatment is balloon valvuloplasty.For these reasons, the cases coming to the operating room are rarely repairable.