DAS 'KLICK SYNDROM', EINE SONDERFORM DER KARDIOMYOPATHIE

Up to a few years ago, the opinion was current that no pathological significance was to be attached to the presence of a late systolic extra sound with a succeeding murmur. In the older text books on phonocardiography or in descriptions of auscultatory phenomena of the heart, it is mentioned that a systolic click mostly results from roughness of the pericardium following pericarditis, that it is frequently combined with a late systolic murmur, and is sometimes present when the heart is healthy or in patients with infundibular chests. More recent investigations of such patients by invasive methods, including angiocardiography, have however shown that these patients have an abnormality of the mitral valve, mostly affecting the posterior cusp. During systole, there occurs, with the lower movement of the plane of the atrium, an infiltration of the much elongated posterior, or also anterior, mitral cusp into the left atrium. The abrup tensioning of the chordae tendineae leads to a high frequency extra sound which mostly occurs in mid or late systole. If the abnormally elongated cusp is so large that the borders of the mitral valve cusps lose contact with one another during systole, mitral valve insufficiency arises in addition in late systole with a corresponding systolic reflux murmur.