late apical systolic murmur

Definition: a murmur previously considered benign, or even extracardiac, with a possible relationship to pericardial disease; it often represents mitral insufficiency, often localized and of moderate severity but with propensity for developing bacterial endocarditis, and is frequently associated with systolic click and mitral prolapse (Barlow syndrome; a balloon or billowing mitral valve leaflet) often producing a click, murmur, or both, as it prolapses during systole into the left atrium.

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