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 valve annuloplasty the cardiac cycle. These changes are primarily due to the dynamic motion of the surrounding mitral valve annulus, a collageneous structure which attaches the mitral leaflets and the left atrium to the ostium of the left ventricle and the aortic root. Throughout the cardiac cycle, the annulus undergoes a sphincter motion, narrowing down the orifice area during systole to facilitate coaptation of the two leaflets and widens during diastole to allow for easy diastolic filling of the left ventricle. This motion is further enhanced by a pronounced three-dimensional configuration during systole, the characteristic saddle shape. These changes throughout the cycle