Complications

Usually, myocarditis goes away without permanent complications. However, severe myocarditis can permanently damage your heart muscle, possibly causing:

• Heart failure. Untreated, myocarditis can damage your heart's muscle so that it can't pump blood effectively. In severe cases, myocarditis-related heart failure may require a ventricular assist device or a heart transplant.
• Heart attack or stroke. If your heart's muscle is injured and can't pump blood, the blood that collects 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, you can have a stroke.
• Rapid or abnormal heart rhythms (arrhythmias). Damage to your heart muscle can cause an abnormal heart rhythm.
• Sudden cardiac death. Certain serious arrhythmias can cause your heart to stop beating (sudden cardiac arrest). It's deadly if not treated immediately.