Endomyocardial fibrosis masquerading as rheumatic mitral incompetence. A report of six surgical cases.

This report presents six cases (among 43 surgical cases) of left ventricular EMF presenting as pure mitral insufficiency without any echocardiographic or hemodynamic signs of left ventricular EMF (except apical diverticulum in two cases). Five of these cases were diagnosed at operation, and the sixth was diagnosed on the basis of a characteristic right ventricular angiogram. At operation a fibrotic lesion localized to the level of the anteropapillary muscle, with severe mitral insufficiency, was found. Five patients underwent successful mitral valve replacement and one a successful conservative mitral valve procedure. Postoperative angiograms, done in two patients, showed a normal contour of the left ventricle. A review of the literature did not reveal any previous descriptions of this type of limited left ventricular EMF, mimicking rheumatic mitral insufficiency. In our surgical experience, we have encountered three types of left ventricular EMF: obliterative, extensive, and limited. We emphasize EMF as a possible cause of mitral insufficiency in African children.