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Myocarditis

Medically reviewed by Drugs.com. Last updated on May 28, 2025.

What is myocarditis?

Harvard Health Publishing

Myocarditis is an inflammation of the heart muscle that may decrease the ability of the heart to pump blood normally. It can be caused by:

Symptoms of myocarditis

The symptoms of myocarditis depend on the cause and severity. For example, many people with uncomplicated myocarditis caused by coxsackievirus don't have any symptoms. Other people have fever, chest pain, cardiac arrhythmias (abnormally fast, slow, or irregular heartbeats), sudden loss of consciousness (syncope), or symptoms related to heart failure (shortness of breath, leg swelling).

Diagnosing myocarditis

Your doctor may suspect myocarditis based on your medical history and symptoms. To confirm the diagnosis, your doctor will examine you, paying special attention to your heart. This will be followed by an EKG (a test that measures the heart's electrical activity), a chest x-ray, an echocardiogram (a test using sound waves to assess heart function), and blood tests.

In some patients, your doctor may order tests to determine if a virus or other infectious agent is the cause. These tests may include blood tests or attempts to detect certain types of viruses from stool, throat washings, or other body fluids.

Expected duration of myocarditis

How long myocarditis lasts depends on the cause and the person's general health before the heart problems began. For example, in many healthy adults with uncomplicated coxsackievirus myocarditis, symptoms can start to improve over a couple of weeks; in other cases, the heart takes a few months to recover. Sometimes, the damage to the heart muscle is permanent, and heart failure persists even after the inflammation has resolved.

Preventing myocarditis

Myocarditis caused by certain infections can often be avoided by vaccination and by practicing good hygiene, especially washing your hands often. HIV can be prevented by following safe sex practices and avoiding intravenous drug use. Myocarditis caused by insect-borne Chagas' disease can be prevented by using effective insecticides in Latin American countries where the illness is common.

Treating myocarditis

Treatment of myocarditis depends on the cause and severity. For example, people with only mild viral myocarditis may recover completely with only a period of rest. They will be advised not to smoke or to drink alcohol, and to limit strenuous activities.

People with myocarditis that causes heart failure symptoms or irregular heartbeat (cardiac arrhythmias) will be treated in a hospital. There they may receive one or more of the following:

When to all a professional

Call your doctor immediately if you have chest pain, even if you think that you are too young to have heart problems (as people of any age can get myocarditis).

Prognosis

In many people with uncomplicated viral myocarditis, the heart muscle improves without specific therapy, and myocarditis-related EKG and echocardiogram abnormalities eventually disappear. However, more severe forms of myocarditis may cause permanent damage to the heart muscle, leading to long-term heart failure and significant abnormalities of heart rhythm.

Additional info

National Heart, Lung, and Blood Institute (NHLBI)
https://www.nhlbi.nih.gov/


Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.