Does mitral prolapse occur in mitral stenosis? Echocardiographic-angiographic observations.

An association between rheumatic fever/rheumatic heart disease and mitral prolapse has been suggested. Since mitral stenosis in adults is a reliable indicator of rheumatic heart disease, we undertook this study to define the association between rheumatic heart disease and prolapse by estimating the frequency with which mitral stenosis and mitral prolapse coexist in the same patient. A second purpose was to assess the usefulness of two-dimensional and standard M-mode echocardiograms in making the diagnosis of mitral prolapse in the presence of mitral stenosis. Twenty patients with moderate to severe mitral stenosis were studied. Standard M-mode echocardiographic criteria for prolapse were used; in the two-dimensional echocardiograms, we searched for arching of the mitral leaflets cephaloposteriorly above the atrioventricular ring. Left ventricular angiograms were evaluated for prolapse both subjectively and objectively by using the posterior medial scallop length index criteria. We found that the majority of these mitral stenosis patients satisfied the M-mode criteria for prolapse, whereas movement of the mitral leaflets into the left atrium by two-dimensional echocardiography and angiography occurred in fewer patients. Three patients met all echocardiographic and angiographic criteria for prolapse, but none had clinical evidence of prolapse. We conclude that the coexistence of mitral prolapse and mitral stenosis, if it occurs at all, is uncommon. M-mode echocardiography alone is unreliable to diagnose prolapse when mitral stenosis is present, since the M-mode criteria for prolapse are met by the majority of mitral stenosis patients.