Erythema multiforme (EM) is a skin reaction that comes from an infection or another trigger. EM is a type of allergic reaction. In most cases, it occurs in response to an infection. In rare cases, it is caused by certain medicines or body-wide (systemic) illness. Infections that may lead to EM include:
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).
Regurgitation is the name for leaking heart valves. Sometimes the condition is minor and may not require treatment, but other times valve regurgitation places a strain on the heart. It can cause the heart to work harder and it may not pump the same amount of blood. Regurgitation occurs when: Blood flows back through the valve as the leaflets are closing.