The mitral valve, also called the bicuspid valve, is a heart valve that lies between the left atrium and the left ventricle and assists in the control of the flow of blood through the heart. The other function of the mitral valve is to prevent the reversal of blood flow from the left ventricle into the left atrium by closing snugly. When the leaflets of the mitral valve relax, that's when they allow oxygenated blood from the lungs into the left ventricle. There are mitral valve conditions that can cause heart failure and other issues. Mitral valve prolapse, mitral valve stenosis, and mitral regurgitation all can lead to heart failure. Find out more about the mitral valve and potential heart failure due to mitral valve problems.