[Familial forms of the mid-end systolic click and murmur syndrome with deviations of left ventricular kinetics].

The aetiology and pathogenesis of the "mid/end-diastolic click and murmur" syndrome, with prolapse of the mitral valves, is obscure in most cases. However, the fact that some cases have had a familial distribution is evidence in favour of a dysgenetic origin. Seven new cases of this type are reported. The authors suggest in this paper that the incidence of the familial form of the syndrome is greater than the literature seems to suggest, and that the syndrome is likely to be due to a malformation. They also emphasise the important part which echocardiography plays in its diagnosis and investigation. Finally, the finding on cine-angiocardiography of specific abnormalities of left ventricular function similar to those found in other studies is indicative of a primary myocardial disorder, associated with subsequent structural alterations of the valvular mechanism.