Myocarditis

Overview

What is myocarditis?

Myocarditis is an inflammation of your heart muscle (myocardium). This makes your heart weaker and makes it more difficult for your heart to pump. This rare condition can affect people quickly or slowly over time.

Myocarditis is different from other types of inflammation because each kind happens in a different part of your heart. Endocarditis affects the inner lining of your heart valves and chambers. Pericarditis affects the sac around your heart.

Rare types of myocarditis include:

  • Lymphocytic myocarditis.
  • Giant cell myocarditis.
  • Fulminant myocarditis.
  • Eosinophilic myocarditis.

Who is at risk for myocarditis?

Some of the things that put you at risk for myocarditis are beyond your control. You are more likely to get myocarditis if:

  • You are a young adult. However, all ages can get it.
  • You are male. But women can get it, too.
  • Your body doesn’t react well to inflammation. Although you don’t inherit myocarditis, your genes have an influence on how your body handles inflammation and how likely you are to get myocarditis.
  • You drink more alcohol than your healthcare provider recommends.

Some medical treatments increase your risk of myocarditis. These include:

  • Dialysis.
  • Implanted heart devices.
  • Radiation.
  • Treatments for heart problems.
  • Having a central venous line.

Having one of these medical problems can put you at a higher risk of getting myocarditis:

  • Diabetes.
  • HIV/AIDS.
  • Skin injuries or infections.
  • Cancer treated with certain medicines.
  • Eating disorders.
  • End-stage kidney disease.
  • Having a chest injury.

Symptoms and Causes

What causes myocarditis?

Many times, the cause of myocarditis is unknown. Most often, the cause is a viral infection. These include:

Other causes of myocarditis include:

Side effects from some medicines can bring about myocarditis. These medicines include:

  • Medicines for the heart.
  • Antidepressants.
  • Medicines for seizures.
  • Antibiotics.
  • Medicines for weight loss.
  • Diuretics.
  • Benzodiazepines.
  • Medicines for psychiatric problems.

In rare cases, myocarditis has happened in young people who received the Pfizer-BioNTech or Moderna vaccines for COVID-19. Most felt better soon after treatment. The CDC considers COVID-19 a greater risk than the risk of vaccine side effects. They recommend the vaccines for young people.

What are the symptoms of myocarditis?

You may have no symptoms, few symptoms or many symptoms, and they may be more severe in some people than in others. Symptoms include:

Diagnosis and Tests

How is myocarditis diagnosed?

Your healthcare provider will use the following to diagnose myocarditis:

  • Physical exam.
  • Medical history.
  • Tests.

What tests will be done to diagnose myocarditis?

Your healthcare provider may order tests to help them decide if you have myocarditis or something else.

These tests include:

Management and Treatment

Does myocarditis go away?

If you have a mild case, it may go away on its own. If not, your provider can order medicines for you.

What is the treatment for myocarditis?

Your healthcare provider may want you to take medication. These include:

  • Medicines for heart failure.
  • Corticosteroids.
  • Intravenous immunoglobulin.

If your myocarditis led to heart failure or an abnormal heart rhythm and your case is serious, you may need surgery to implant:

Prevention

How can I reduce my risk of myocarditis?

Unfortunately, it’s very hard to avoid many of the things that cause myocarditis. Your best bet is to stay healthy to keep from getting the infections that can bring about myocarditis. Limiting your alcohol intake and not taking illegal drugs are other risk factors you can control.

Outlook / Prognosis

What is my prognosis with myocarditis?

Many people can live for years without problems after myocarditis treatment. Other people may need to keep taking medication. There is a small risk of myocarditis happening again.

For some people, myocarditis can lead to dilated cardiomyopathy and they may need a heart transplant. Almost 20% of sudden deaths in young people have a connection to myocarditis.

What are the possible complications of myocarditis?

In some people, myocarditis can bring on other issues, such as:

Living With

How do I take care of myself with myocarditis?

Once you’ve had myocarditis, you can get it again years later. Tell your provider if you get symptoms again. For your best chance of staying healthy:

  • Be sure to keep your follow-up appointments with your provider.
  • Keep taking prescribed medicines.
  • Don’t exercise until your provider says you can.
  • Limit salt in your diet.
  • Stop smoking and/or using tobacco products.
  • Don't drink alcohol.

Also, they may want to repeat some tests used for diagnosis. These include:

  • Echocardiogram.
  • MRI (magnetic resonance imaging).

What questions should I ask my doctor?

  • What caused my myocarditis?
  • Will I need treatment for my myocarditis?
  • What can I do to stay healthy?

A note from Cleveland Clinic

Myocarditis is a rare condition that can weaken your heart muscle. Unfortunately, there are many causes of myocarditis that are hard to avoid. While symptoms can be severe in some people, many people can live for years without myocarditis becoming a problem again after treatment. The best thing you can do is keep your follow-up appointments with your provider, keep taking the medicines they prescribed for you and let them know if you get symptoms again.

Last reviewed by a Cleveland Clinic medical professional on 11/30/2021.

References

  • National Heart, Lung, and Blood Institute. Heart Inflammation. (https://www.nhlbi.nih.gov/health-topics/heart-inflammation) Accessed 11/30/2021.
  • Merck Manual Consumer Version. Myocarditis. (https://www.merckmanuals.com/home/heart-and-blood-vessel-disorders/pericardial-disease-and-myocarditis/myocarditis?query=myocarditis) Accessed 11/30/2021.
  • Myocarditis Foundation. About Myocarditis. (https://www.myocarditisfoundation.org/about-myocarditis/) Accessed 11/30/2021.
  • CDC. Myocarditis and Pericarditis Following mRNA COVID-19 Vaccination. (https://www.cdc.gov/coronavirus/2019-ncov/vaccines/safety/myocarditis.html) Accessed 11/30/2021.

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