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 during strenuous exercise. Patients with viral myocarditis often exhibit pericarditis (inflammation of the lining around the heart), as well.
- Shortness of breath.
- Heart palpitations or rapid heartbeat.
- Chest pain.
- Congestive heart failure.
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. Other causes may include:
- Certain chemicals and drugs (such as immuno suppressants).
- 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).
- Toxins released in the course of diphtheria infections.
- Rheumatic fever.
- Lyme disease.
The Johns Hopkins Cardiomyopathy and Heart Failure Practice, directed by Stuart Russell, MD, manages myocarditis. The practice uses a multidisciplinary approach to evaluate and manage patients with heart failure due to any cause. Important components of this team approach include social work, dietary counseling, physical rehabilitation, educational programs and support groups. Our goal is to empower patients to better care for themselves. We believe that transplantation is the “court of last resort” and will do everything possible to avoid transplantation.
To be evaluated for myocarditis, a Johns Hopkins physician will first examine you at our Outpatient Center or satellite facility at Green Spring Station. If necessary, you may be asked to undergo one or more of the following tests. Blood tests and electrocardiograms are performed at the outpatient locations. Biopsies are done in the hospital’s Cardiovascular Diagnostic Laboratory.
- Endomyocardial biopsy is the best way to diagnose myocarditis. In this procedure, your doctor will take a small piece of tissue from your heart to examine under a microscope.
- Your doctor may order blood tests to check for signs of infection.
- An electrocardiogram, also called an ECG or EKG, records your heart’s electrical activity during rest to determine abnormal heart rhythms.
Determining the proper therapy for myocarditis is controversial. Some doctors believe in suppressing the immune system using medications while others do not. Most cases subside in a few weeks without medical treatment.
At Johns Hopkins, myocarditis is managed by the Cardiomyopathy and Heart Failure Practice, described in the previous section.
Lifestyle changes such as consuming a low-salt diet and not drinking alcohol may help in the management of myocarditis. If your case is severe, your doctor may recommend bed rest to minimize the workload on the heart. Do not exercise without checking with your doctor first.
Your doctor may also prescribe a variety of medications. Antibiotics help treat the bacterial infection causing myocarditis. Corticosteroid drugs may be prescribed to reduce inflammation of the heart wall and speed recovery. Other medications may be needed to treat congestive heart failure or arrhythmias.
Ventricular Assist Devices are also available as a treatment option.
In very severe cases, your doctor may recommend a heart transplant for congestive heart failure.