Mitral valve prolapse, or MVP, is one of the most common heart conditions affecting the valves of the heart. It affects about 3 to 4 percent of the U.S. population and is more common in women. The job of the mitral valve is to regulate blood flow from the left atrium to the heart’s main pumping chamber, the left ventricle. Normally, the mitral valve opens when the heart muscle is relaxing to let the blood through to the left ventricle and when the heart muscle contracts, it shuts so the blood doesn't leak back in. With mitral valve prolapse, instead of closing evenly, part of the valve bulges