[The anatomical forms of mitral incompetency (author's transl)].

A change in any of the parts of the mitral valve apparatus may cause systolic leakage: the mitral ring, the large and small valve, the papillary muscles and the chordae tendinae, hence the possibility of a large number of anatomical and physiological mechanisms and many possible etiologies in the onset of mitral incompetency. For each of the four anatomical constituents of the mitral valve these mechanisms are successively reviewed and their etiologies considered, as various as the sequelae of rheumatic or infective endocarditis, metamorphic calcifications, mucoid degeneration, ischemic or other myocardial changes, constitutional abnormalities. Each type of mitral incompetency has a variable effect on the heart cavities and the pulmonary circulation.