Mitral valve stenosis gradient across the mitral valve increases, the amount of time necessary to fill the left ventricle with blood increases. Eventually, the left ventricle requires the atrial kick to fill with blood. As the heart rate increases, the amount of time that the ventricle is in diastole and can fill up with blood (called the diastolic filling period) decreases. When the heart rate goes above a certain point, the diastolic filling period is insufficient to fill the ventricle with blood and pressure builds up in the left atrium, leading to pulmonary congestion. When the mitral valve area goes less than 1
Mitral valve annuloplasty the native annulus and some of its natural dynamics. The goal of semi-rigid rings is to maintain coaptation and valve integrity during systole, while allowing for good hemodynamics during diastole. Rigid rings are designed to provide rigid support in large dilation and under high-pressure. Annuloplasty devices usually come in different sizes. The surgeon can estimate the dimensions of the patient’s mitral valve and decide on an appropriate ring size. Depending on the disease etiology, different approaches are taken. Surgeons can decide to "undersize" the device, "truesize" the device, or "oversize" it. Annuloplasty devices are classified by the U.S. Food and