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).
Read more about regurgitation and specific valves: 1  Mitral regurgitation is leakage of blood backward through the mitral valve each time the left ventricle contracts.  Aortic valve regurgitation may stem from a congenital heart defect, complications of an infection or other more rare causes.