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).
One issue in particular is called mitral valve regurgitation and it occurs when the valve does not close properly, allowing the blood to flow backward into the upper heart chamber. When this happens, there can be a lack of blood flow to the rest of the body that can ultimately lead to congestive heart failure.