What is Myocarditis?
Information provided by the Myocarditis Foundation
Myocarditis is a disease marked by inflammation and damage of the heart muscle. Although the exact incidence of myocarditis is not known, it is estimated that several thousand patients per year are diagnosed in the United States. Myocarditis usually attacks otherwise healthy people. It is believed that 5 to 20% of all cases of sudden death in young adults are due to myocarditis.
There are many causes of myocarditis, including viral infections, autoimmune diseases, environmental toxins, and adverse reactions to medications. The prognosis is variable but chronic heart failure is the major long term complication. Myocarditis and the associated disorder of idiopathic dilated cardiomyopathy are the cause of approximately 45% of heart transplants in the United States.
Myocarditis is uncommon and can be caused by a viral infection or a self-directed immune response (this is when the person’s own immune system attacks the body, such as in autoimmune diseases like rheumatoid arthritis or lupus). Some autoimmune diseases can affect the heart and cause myocarditis. Rare cases have also been associated with a variety of infections, toxic injuries, adverse drug reactions, and even cancer.
Most cases of myocarditis have no symptoms and are only identified by an electrocardiogram or by blood tests that detect heart injury.
Because myocarditis is rare, the best way to diagnose and treat the disease is not known, but research is being done.
What Causes Myocarditis?
Myocarditis can be caused by many viruses, but the most common are those associated with upper respiratory tract infections. Less commonly, other contagious diseases, including Lyme disease, may cause myocarditis. Rarely, myocarditis has been caused by cocaine use or exposure to toxic agents including metal poisons or snake or spider bites.
Most cases of myocarditis are not infectious. There is no known risk of infection to family members of people with myocarditis.
What are the Symptoms of Myocarditis?
The most common symptom of myocarditis is shortness of breath during exercise or exertion. This symptom usually develops 7 to 14 days after a viral illness and can progress to shortness of breath at night, which may require that you sit up to breathe.
Other symptoms may include fatigue, heart palpitations and chest pain or pressure. The legs also may swell. Rarely, myocarditis causes a sudden loss of consciousness that may be due to abnormal heart rhythms. In summary, patients may experience some, all or none of the following symptoms: shortness of breath, chest pain, lightheadedness, irregular heartbeat, sudden loss of consciousness.
How is Myocarditis Treated?
Myocarditis is commonly treated with medications used to treat heart failure. Rest and a low-salt diet are often recommended. Steroids and other medications also may be used to reduce heart inflammation.
More rarely, if an abnormal heart rhythm is present, treatment may require additional medications, a pacemaker or even a defibrillator.
Discuss treatment options with your health-care team.
What Can be Done to Prevent Myocarditis?
No lifestyle changes or medical treatments are known to prevent viral myocarditis.
Because myocarditis is rare, information is limited regarding its causes and effective treatments. Myocarditis is not believed to be inherited. No genes are known to predispose people to myocarditis.
To learn more, please visit the following web sites:
http://www.myocarditisfoundation.org/research-and-grants/
http://www.myocarditisfoundation.org/research-and-grants/faqs/
http://www.myocarditisfoundation.org/about-giant-cell-myocarditis/
http://www.texaschildrenshospital.org/
http://www.carditis.net/