Chronic Mitral Regurgitation

Chronic mitral regurgitation may have different aetiological factors:

1) Rheumatic

2) Degenerative-myxomatous malformation

3) Infective endocarditis

4) Mitral valve prolapse syndrome

5 ) Ischaemic--due to papillary muscle dysfunction or annular dilatation due to left ventricular enlargement

6) Sub valvar mitral aneurysm.

In severe chronic mitral regurgitation left ventricular after load is low because the LV ejection is partly into the left atrium. Due to this the LV ejection fraction may be spuriously high even when LV dysfunction has set in. So it is essential to assess the end systolic dimensions of left ventricle in recommending surgery. These days excellent 2D echo and doppler studies are available and these are used to assess (1) mitral regurgitant fraction, (2) LV ejection fraction, and (3) left ventricular dimension to decide on the necessity and timing of surgery in chronic mitral regurgitation.