Different mechanisms of mitral regurgitation in acute and chronic forms of coronary heart disease.

Contradictory two-dimensional echocardiographic findings have been reported in relation to the role of prolapse of the mitral valve and lack of systolic leaflet coaptation in mitral regurgitation secondary to coronary heart disease. A prospective study of 22 patients with chronic coronary heart disease and mitral regurgitation showed the following: Inferior akinesia was detected in 14 (64%), fibrosis of the postero-medial papillary muscle in 10 (45%), and prolapse of the mitral valve in nine (41%). A combination of the three signs was seen in six patients (27%). Lack of systolic leaflet coaptation was seen in only two patients, both with anterior myocardial infarction. When these results are compared with those reported in the literature, it is apparent that in acute coronary heart disease, lack of leaflet coaptation is frequently visualized (P less than 0.01) and fibrosis of the postero-medial papillary muscle and prolapse of the mitral valve are lacking (P less than 0.01). A unitary explanation of all forms of mitral regurgitation in coronary heart disease is misleading; mechanisms of mitral regurgitation in coronary heart disease depend on the clinical presentation--acute or chronic, the site of infarction, and the presence of cardiac dilatation.