When myocarditis is severe, it can permanently damage your heart muscle. This damage may cause:

  • Heart failure. Left untreated, myocarditis can damage your heart's muscle to the point it can no longer pump blood effectively, causing heart failure. In very severe cases, myocarditis-related heart failure requires an artificial heart or heart transplant.
  • Heart attack or stroke. If your heart's muscle is injured and can't pump blood, the blood that pools in your heart can form clots. If a clot blocks one of your heart's arteries, you can have a heart attack. If a blood clot in your heart travels to an artery leading to your brain before becoming lodged, you can have a stroke.
  • Irregular heartbeats (arrhythmias). Damage to your heart muscle can cause disturbances in your heartbeat (arrhythmias).
  • Sudden death. If your heart muscle is so damaged that you develop an arrhythmia, it's possible the arrhythmia could cause your heart to suddenly stop beating (sudden cardiac arrest). If not treated immediately, it causes sudden cardiac death.
May 02, 2012