Mitral valve replacement the bottom of the heart through a tube inserted in a small incision in the patient’s chest. The physician uses the tube to deploy the valve and positions it so that it rests over the heart's existing mitral valve. It is then anchored securely in place by an adjustable tether. The valve is fully retrievable, totally repositionable and is sewn onto a Nitinol frame. Nitinol is a superelastic nickel and titanium "shape memory alloy" whose flexibility eases implantation, but regains its original shape when it returns to a patient’s normal body temperature. The transition of TMVR from concept to reality
Mitral valve about 20% to the volume in the left ventricle prior to ventricular systole, and is known as the "atrial kick". The mitral annulus changes in shape and size during the cardiac cycle. It is smaller at the end of atrial systole due to the contraction of the left atrium around it, like a sphincter. This reduction in annulus size at the end of atrial systole may be important for the proper coapting of the leaflets of the mitral valve when the left ventricle contracts and pumps blood. Leaking valves can be corrected by mitral valve annuloplasty, a common surgical procedure