Myocarditis is an inflammation of the heart’s muscular wall, the myocardium. Although rare, it can be devastating. Myocarditis can occur with no symptoms and remain undiagnosed.

Healthy Myocardium
normal heart section
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Many cases of myocarditis have no identifiable cause. This is called idiopathic myocarditis. When a cause is identified, it falls into one of 3 categories:

  • Infectious—bacterial, viral, or fungal
  • Toxic—medications, or exposure to heavy metals, toxins, or physical agents (shock, radiation)
  • Immune-mediated—allergic reactions, heart transplant rejection, or autoantigens (which may be present in autoimmune disorders)