A transcatheter mitral valve repair (TMVR) is a minimally invasive procedure for treating mitral valve regurgitation, a condition in which the valve between the heart's left chambers doesn't close properly. In a healthy heart, valves open and shut tightly during each heartbeat, controlling blood flow through the heart and out to the rest of the body. When the mitral valve doesn't close well, blood leaks backward and the heart is forced to work harder. Pressure may build in the lungs, and people may feel tired or short of breath.