Head and neck lymphedema can be caused by surgery or radiation therapy for tongue or throat cancer. It may also occur in the lower limbs or groin after surgery for colon, ovarian or uterine cancer, in which removal of lymph nodes or radiation therapy is required.
1 Heart attack. A heart attack can damage the area of the heart muscle that supports the mitral valve, affecting the function of the valve. If the damage is extensive enough, a heart attack can cause sudden and severe mitral valve regurgitation.  Abnormality of the heart muscle (cardiomyopathy).
1 Sometimes mitral valve prolapse causes mitral valve regurgitation. 2  If the prolapse is severe, the valve leaflets can become disconnected from tendons that stretch between the leaflets and the heart muscle. 3  This can cause the valve to malfunction.roblems with the mitral valve include: 1  Mitral stenosis: The leaflets are fused, are too thick, or there is some other structural defect in the valve leaflets. 2  Sometimes, mitral stenosis occurs as a result of surgery to repair an abnormal mitral valve.