Thromboembolic studies in the patient with the prolapsed mitral valve. Has Salome dropped another veil?

THE PROLAPSED MITRAL VALVE, or clickmurmur syndrome, continues to evoke interest, concern and controversy. Although the midsystolic click and late systolic murmur were well described in the late 19th century,1 it was not until 1961 that Reid2 suggested the mitral valve as the cause of the click and mitral insufficiency as the cause of the murmur. This was confirmed by angiocardiography and phonocardiography. Subsequently, noninvasive identification of the presence of mitral valve prolapse became possible by echocardiography. When population studies were done, the prevalence of mitral valve prolapse by physical or echocardiographic findings varied from 5-20%.?-7 If both echocardiographic and auscultatory evidence is required before mitral valve prolapse is diagnosed, the prevalence in the population is 5-10%. Although Barlow7 described a subgroup of these patients who were symptomatic with chest pain (usually atypical for angina), palpitations, dizziness, and T-wave ECG changes, the finding of click-late systolic murmur had been assumed to be benign, even a normal variant. Anecdotal evidence that this apparently common problem was not entirely benign began to accumulate in the form of case reports describing the development of sudden severe mitral insufficiency, often associated with rupture of the chordae tendineae, occasional cases of infective endocarditis, atrial and ventricular arryhythmias (including runs of ventricular tachycardia) and, most distressingly, occasional reports of sudden death. Out of this Pandora's box called prolapsed mitral valve, an increasing number of serious and frightening complications continue to emerge. The latest problem reportedly associated with the prolapsed mitral valve is stroke, presumably thromboembolic. In 1976, in a prospective study of patients with transient cerebral ischemic attacks and partial, nonprogressing strokes, Barnett et al.8 reported finding 12 patients with angiocardiographically proved mitral valve prolapse out of 166 patients, and suggested an etiologic relationship. In this issue of Circulation, Steele and colleagues report evidence that patients with mitral valve prolapse and stroke have a decreased platelet survival