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Myocarditis

Inflammation - heart muscle

Last reviewed: June 7, 2012.

Myocarditis is inflammation of the heart muscle.

See also: Pediatric myocarditis

Causes, incidence, and risk factors

Myocarditis is an uncommon disorder that is usually caused by viral, bacterial, or fungal infections that reach the heart.

Viral infections:

Bacterial infections:

Fungal infections:

  • Aspergillus
  • Candida
  • Coccidioides
  • Cryptococcus
  • Histoplasma

When you have an infection, your immune system produces special cells that release chemicals to fight off disease. If the infection affects your heart, the disease-fighting cells enter the heart. However, the chemicals produced by an immune response can damage the heart muscle. As a result, the heart can become thick, swollen, and weak. This leads to symptoms of heart failure.

Other causes of myocarditis may include:

  • Allergic reactions to certain medications or toxins (alcohol, cocaine, certain chemotherapy drugs, heavy metals, and catecholamines)
  • Being around certain chemicals
  • Certain diseases that cause inflammation throughout the body (rheumatoid arthritis, sarcoidosis)

Symptoms

There may be no symptoms. Symptoms may be similar to the flu. If symptoms occur, they may include:

  • Abnormal heartbeat
  • Chest pain that may resemble a heart attack
  • Fatigue
  • Fever and other signs of infection including headache, muscle aches, sore throat, diarrhea, or rashes
  • Joint pain or swelling
  • Leg swelling
  • Shortness of breath

Other symptoms that may occur with this disease:

Signs and tests

A physical examination may show no abnormalities, or may reveal the following:

  • Abnormal heartbeat or heart sounds (murmurs, extra heart sounds)
  • Fever
  • Fluid in the lungs
  • Rapid heartbeat (tachycardia)
  • Swelling (edema) in the legs

Tests used to diagnosis myocarditis include:

Treatment

Treatment is aimed at the cause of the problem, and may involve:

  • Antibiotics
  • Anti-inflammatory medicines to reduce swelling
  • Diuretics to remove excess water from the body
  • Low-salt diet
  • Reduced activity

If the heart muscle is very weak, your health care provider will prescribe medicines to treat heart failure. Abnormal heart rhythms may require the use of additional medications, a pacemaker, or an implantable cardioverter-defibrillator. If a blood clot is in the heart chamber, you will also receive blood thinning medicine.

Expectations (prognosis)

How well you do depends on the cause of the problem and your overall health. The outlook varies. Some people may recover completely. Others may have permanent heart failure.

Calling your health care provider

Call your health care provider if you have symptoms of myocarditis, especially after a recent infection.

Seek immediate medical help if you have severe symptoms or have been diagnosed with myocarditis and have increased:

Prevention

Promptly treating conditions that cause myocarditis may reduce the risk.

References

  1. Liu P, Baughman KL. Myocarditis. In: Bonow RO, Mann DL, Zipes DP, Libby P, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 9th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 70.
  2. McKenna W. Diseases of the myocardium and endocardium. In: Goldman L, Schafer AI, eds. Cecil Medicine. 24th ed. Philadelphia, PA: Saunders Elsevier; 2011:chap 60.

Review Date: 6/7/2012.

Reviewed by: Glenn Gandelman, MD, MPH, FACC Assistant Clinical Professor of Medicine at New York Medical College, and in private practice specializing in cardiovascular disease in Greenwich, CT. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M. Health Solutions, Ebix, Inc.

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Copyright © 2013, A.D.A.M., Inc.

A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows rigorous standards of quality and accountability. A.D.A.M. is among the first to achieve this important distinction for online health information and services. Learn more about A.D.A.M.'s editorial policy, editorial process and privacy policy. A.D.A.M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health on the Net Foundation (www.hon.ch).

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only — they do not constitute endorsementscof those other sites. © 1997–2011 A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.

Copyright © 2013, A.D.A.M., Inc.

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  • Corticosteroids may be effective in treating people with viral myocarditisCorticosteroids may be effective in treating people with viral myocarditis
    Viral infection occasionally triggers myocarditis (inflammation and necrosis of the heart muscle) which can result in severe, acute heart failure. The first signs of this condition may be flu‐like symptoms which evolve into non‐specific chest discomfort, shortness of breath or palpitations. The majority of patients recover spontaneously but others have continuing heart problems which require medication and can be severe enough to cause death.
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