Non-rheumatic acute mitral insufficiency caused by ruptured chordae tendineae.

Five patients with proved mitral insufficiency caused by ruptured chordae tendineae were examined. Two patients came to autopsy without cardiac cateterization. Three patients, who had cardiac cateterization and surgical replacement of their mitral valves, improved dramatically. Two additional patients have been clinically diagnosed and have had corroborative cardiac catheterization and are being observed in anticipation of possible future valve replacement. Similar findings in these seven patients include adult onset of a characteristic systolic heart murmur which mimics aortic valvular stenosis, acute pulmonary edema associated with massive mitral insufficiency in the face of a normal sized or only minimally enlarged left atrium, and variable size of the left ventricle. In none of the patients were there historical or physical findings of trauma or rheumatic or bacterial endocarditis. A wide spectrum of clinical courses may be explained by the variable number of ruptured chordae tendineae at the time of clinical presentation. Although the incidence and etiology are uncertain, we believe this entity is not uncommon. Myxomatous degeneration of the connective tissue of the heart was present, but the cause remains unknown.