CLICK-MURMUR SYNDROME A MEDICAL PENDULUM AND A UNIFYING CONCEPT

In the click murmur syndrome, the underlying mechanism has one common denominator, namely the suspension apparatus of the mitral valve is too big, either absolutely or relatively, for the left ventricular cavity to contain. In coronary artery disease with papillary muscular dysfunction, 2 mechanisms, one morphologic and the other hemodynamic, either alone or in combination account for the late systolic timing of the murmur. Another related observation is the frequent association of the congenital absence of the left circumflex artery in the click murmur syndrome. The observation of multiple systolic clicks and late systolic murmur appearing de novo following closed mitral commissurotomy point to the unsupported redundant valve leaflet as the responsible mechanism. The other important mechanism is present in diseases associated with a reduced end-systolic volume of the left ventricle.