Mitral valve stenosis the pressures in the left atrium and the left ventricle during ventricular diastole will be equal. The result is that the left ventricle gets filled with blood during early ventricular diastole, with only a small portion of extra blood contributed by contraction of the left atrium (the "atrial kick") during late ventricular diastole. When the mitral valve area goes below 2 cm, the valve causes an impediment to the flow of blood into the left ventricle, creating a pressure gradient across the mitral valve. This gradient may be increased by increases in the heart rate or cardiac output. As the
Mitral insufficiency subsequent displacement of the papillary muscles and the dilatation of the mitral valve annulus. Rheumatic fever (RF) and Marfan's syndrome are other typical causes. Mitral valve stenosis (MVS) can sometimes be a cause of mitral regurgitation (MR) in the sense that a stenotic valve (calcified and with restricted range of movement) allows backflow (regurgitation) if it is too stiff and misshapen to close completely. Most MVS is caused by RF, so one can say that MVS is sometimes the proximal cause of MI/MR (that is, stenotic MI/MR) and that RF is often the distal cause of MVS, MI/MR, or both.