Table 1

Mechanisms of mitral regurgitation

Disease processProbable mechanism of regurgitation
LV, left ventricular, MR, mitral regurgitation.
▸ Myxomatous mitral valve diseaseExcess leaflet motion (chordal rupture, leaflet prolapse)
▸ Rheumatic mitral valve diseaseRestricted leaflet motion (chordal shortening and fusion, increased leaflet stiffness)
▸ EndocarditisDestruction of valve tissue
▸ Coronary artery disease
    Papillary muscle ruptureFlail papillary muscle and leaflet
    Infarction of papillary muscle or inferior-posterior LV wallAbnormal tethering of chordae and leaflet
    Ischaemic of inferior-posterior LV wallIntermittent MR caused by abnormal chordal tethering
    End stage disease with LV dilation and systolic dysfunctionAltered angle between papillary muscle and mitral annulus, annular dilation
▸ Dilated cardiomyopathyAltered angle between papillary muscle and mitral annulus