[Regression of mitral valve prolapse to a state masquerading as dilated cardiomyopathy: a case report]

A 40-year-old man was admitted to our hospital in May 1982 for evaluation of a heart murmur. A standard 12-lead electrocardiogram (ECG) showed an abnormal Q wave in lead III. Echocardiography revealed prolapse of the anterior mitral valve leaflet (MVP), but neither dilatation nor wall motion abnormalities of the left ventricle (LV) were observed. Thallium-201 scintigraphy revealed an abnormal thallium uptake at the apex and inferior wall. He had no episode of acute myocardial infarction or myocarditis, but complete right bundle branch block suddenly appeared, and he was hospitalized in October 1984. He had no coronary artery lesions, and only mild mitral regurgitation on left ventriculography. The motion of the interventricular septum and apex was reduced on echocardiography and a persistent perfusion defect was observed at the inferior wall and the interventricular septum on T1-201 scintigraphy. In December 1985, he experienced an Adams-Stokes attack due to complete atrioventricular block. Echocardiographically, the left ventricle became enlarged and the wall motion abnormality and a perfusion defect on T1-201 scintigrams were of relatively severe degree. Thus, left ventricular dilatation and wall motion abnormality may progress in some cases of MVP as it did in this one. We consider this case a very interesting one in speculating on the relationship between MVP and DCM.