Myocarditis
What is it?
Myocarditis is an inflammation of the heart muscle (myocardium), usually due to a viral infection. In many cases myocarditis produces no noticeable symptoms, although severe cases may cause serious disturbances of the heartbeat (cardiac arrhythmia), weakness of the heart muscle (cardiomyopathy), heart failure, or sudden cardiac arrest.While in most instances the inflammation subsides on its own without treatment and without causing permanent damage, more severe cases or those that become chronic may require hospitalization and medical treatment. Myocarditis can affect people of all ages. Because it is often asymptomatic, it is sometimes diagnosed only after a young adult with heart damage due to chronic myocarditis dies unexpectedly. Patients with viral myocarditis often exhibit pericarditis (inflammation of the lining around the heart; see Pericarditis) as well.
What Causes It?
- Viral infections, including Coxsackie virus, measles, rubella, influenza, and polio-, adeno-, and echoviruses, are the most common cause of myocarditis in the United States.
- Bacterial infection is a rare cause.
- Parasitic infections such as trichinosis and toxoplasmosis (both rare in the United States).
- Chagas' disease, due to the parasite Trypanosoma cruzi (a common cause of heart disease in Central and South America).
- Rheumatic fever.
- Lyme disease.
Prevention
- Vaccinations for diphtheria, tetanus, measles, rubella, and polio should be kept current.
- Get prompt treatment for infections, especially those of the upper respiratory system.
Diagnosis
- Patient history and physical examination.
- Blood tests.
- Electrocardiogram (ECG), which measures the electrical activity of the heart.
- Endomyocardial biopsy (removal of a small sample of heart muscle with a needle for microscopic analysis) provides a definitive diagnosis.
How to Treat It
- Most cases subside in a few weeks without medical treatment. Studies have indicated that exercise may be risky for those with myocarditis, so all strenuous activity should be avoided. Bed rest is generally recommended in severe cases during convalescence to minimize the workload on the heart. A low-salt diet and abstinence from alcohol may also be advised.
- Antibiotics are prescribed for bacterial infection.
- In some cases corticosteroid drugs may be prescribed to reduce inflammation of the myocardium and to speed recovery.
- Appropriate medications may be needed to treat congestive heart failure or arrhythmias.
- In very severe cases heart transplantation may be recommended for congestive heart failure.
When to Call a Doctor
- Call a doctor if you develop the symptoms of myocarditis, especially if you have a recent history of infection.
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Copyright © 2008 Medletter Associates, LLC
Content excerpted from Johns Hopkins Symptoms and Remedies: The Complete Home Medical Reference.