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).
Mitral valve regurgitation means that one of the valves in your heart-the mitral valve-is letting blood leak backward into the heart. Heart valves work like one-way gates, helping blood flow in one direction between heart chambers or in and out of the heart. The mitral valve is on the left side of your heart.