Myocarditis is inflammation of the heart muscle. It may occur after an infection, such as diphtheria, rheumatic fever, or tuberculosis. It may also happen with other damage to the heart from toxins, certain drugs, or an autoimmune disease.

The inflammation is part of an immune system response. The body's natural defense system attacks the heart. This can cause serious heart problems, such as dilated cardiomyopathy and heart failure. With these problems, the heart can't pump blood as well as it should.

Myocarditis should be treated by a doctor as soon as possible.


What are the symptoms of myocarditis?

You may be short of breath. You may also have chest pain, feel tired, or have palpitations. (This is the uncomfortable feeling that your heart is beating fast or not in the usual way).

Some of these symptoms are similar to symptoms of other heart problems, such as heart failure.

In some cases, there may not be any symptoms. Your doctor may find signs of myocarditis while doing other tests on your heart.


How is myocarditis diagnosed?

Your doctor will give you some tests if you have symptoms of myocarditis. You may get an electrocardiogram (EKG or ECG). You may also get other imaging tests like an echocardiogram or MRI. You may get lab tests. Blood tests might be done to check for heart muscle injury.

You may also need a biopsy in some cases. A biopsy (sample of heart tissue) can confirm if you have myocarditis. And it may help the doctor find the cause.


How is myocarditis treated?

Treatment for myocarditis includes finding and treating the cause. If you are having other serious heart problems, your doctor will treat those at the same time. You may need to take medicine for your heart.

If a bacterial infection is the cause, you may need to take antibiotics. Lifestyle changes, such as getting more rest, may be part of the treatment.

Many people recover completely from myocarditis. But some people may have long-term problems from it.

Copyrighted material adapted with permission from Healthwise, Incorporated. This information does not replace the advice of a doctor.