The prolapsing or billowing mitral valve syndrome has received much attention in recent years because of both its ubiquity and the occasional occurrence of serious problems in relation to it.1-4
Several physical findings have been related to this condition. The most striking and frequent finding is a midsystolic click (or clicks), which is followed frequently by a late systolic murmur.5,6 Some patients have had a holosystolic murmur, sometimes rather intense, without any click at all.5-7 Other patients demonstrate completely normal results of cardiac examinations in the presence of typical echocardiographic and angiographic evidence of prolapse.8,9
We have recently observed a patient with this syndrome who demonstrated, in addition to the midsystolic click and late systolic murmur, a striking early diastolic sound. Echocardiographic and phonocardiographic studies were carried out, along with pharmacologic interventions, in an effort to determine the nature of this sound.
PATIENT SUMMARY
A 37-year-old