Mitral valve prolapse: harbinger of death or variant of normal?

Mitral valve prolapse: harbinger of death or variant of normal? It is 21 years since Barlow and colleagues recognised prolapse of the posterior leaflet of the mitral valve during angiography and related this to the auscultatory phenomena of the late systolic click and murmur.' Two years earlier in 1961 Reid, also from South Africa, had first proposed that the features were of mitral rather than pericardial origin as had previously been thought.2 The pathogenesis of mitral valve prolapse has been fully described and related to the clinical features.3-6 A floppy mitral valve, Barlow's billowing leaflet, is common in some of the connective tissue diseases, particularly Marfan's syndrome; family studies have suggested that it is often hereditary; an association has been found with slender body build and the straight back syndrome; and the myxomatous transformation which is usually found in the redundant leaflet has been described as a possible forme fruste of the Marfan syndrome but is most frequent in middle aged or elderly people7 as a degenerative or wear and tear phenomenon. The development of echocardiography gave further confirmation of the mechanism of the auscultatory phenomena , aiding clinical recognition of the condition. Mitral valve prolapse became a popular diagnosis and was often recognised in patients without abnormal clinical features. Mitral valve prolapse is now sought by echocardiography whenever an explanation is required for symptoms of possible cardiac origin, having gradually become associated with atypical chest pain,8 palpitations caused by both supraventricular9 and ventricular arrhythmias,'° syncope," dyspnoea," 12 neurotic symptoms,' and with what used to be called Da Costa's or "effort syndrome."'3 Mitral valve prolapse has also been cited as one of the most frequent determinants of infective endocarditis'4 5 and of progressive mitral regurgitation needing replacement of the mitral valve."''" Platelet embolism may lead to transient ischaemic attacks'9 or visual disturbance.20 A distinctive electrocardio-graphic pattern of inferolateral T wave inversion,2' which is inconstant, has been associated with abnormal left ventricu-lar shape and performance22; angina-like pain in the presence of angiographically normal coronary arteries; ventricular ectopic activity; and sudden death sometimes attributed to a "partial cardiomyopathy."2324 This formidable list of the complications of mitral valve prolapse suggests that it is a serious condition, and in a recent study from Manchester of 182 patients the authors concluded that the long term prognosis was not as good as had been generally believed.8 By contrast, a retrospective analysis of the fate of patients …