The mechanism of mitral valve stenosis in RF:

It is fusion of the commissures ( The analogy that was used - imagine that you sewed together the corners of your mouth and also that the valve resembles the mouth of a fish- hence the name fish mouth valve). There is scarring of the valve that inhibits the valve's fused commissures to allow it to open to its fullest extent. This fusion is the classic post inflammatory RF lesion.

The commissures are once again fused but now the valve also has a fixed opening. The insufficiency is the consequence of the rolling back of the edges of the valve leading to a permanent somewhat rectangular opening. This picture has already been presented with the aortic valve as well, but the difference lies in the fact that the mitral valve has other components that the aortic does not have. Namely, the cordae tendini and papillary muscles which can of course be affected in mitral valve disease.

The valve appears to have had molten candle wax drip down over it. The cordae become thick, fused, and shortened as a consequence of the damage. Therefore, the leaflet of the valve almost seems to directly insert into the top of the papillary muscle. The consequences of this retraction of the cordae are the insufficient closure of the valve.

Category: Pathology Notes