In mild cases, myocarditis may have no noticeable symptoms. You may feel ill and have general symptoms of a viral infection and never realize your heart is affected.
In serious cases, the signs and symptoms of myocarditis vary, depending on the cause of the disease. Common myocarditis symptoms include:
- Chest pain
- A rapid or abnormal heartbeat (arrhythmia)
- Shortness of breath, at rest or during physical activity
- Fluid retention with swelling of your legs, ankles and feet
- Other signs and symptoms you'd have with a viral infection, such as a headache, body aches, joint pain, fever, a sore throat or diarrhea
Myocarditis in children
When children develop myocarditis, they may have these signs and symptoms:
- Breathing difficulties
- Rapid breathing
- Bluish or grayish discoloration of the skin
When to see a doctor
Call your doctor if you have any of the symptoms of myocarditis, particularly chest pain and shortness of breath. If you've had an infection, be alert for the symptoms of myocarditis and let your doctor know if they occur. If you have severe symptoms, go to the emergency room or call for emergency medical personnel.
Often, the exact cause of an individual case of myocarditis isn't identified. However, there are numerous potential causes of myocarditis, such as:
- Viruses. Viruses commonly associated with myocarditis include coxsackievirus B, which can cause symptoms similar to a mild case of flu; the viruses that cause the common cold (adenovirus); and parvovirus B19, which causes a rash called fifth disease. Gastrointestinal infections (echoviruses), mononucleosis (Epstein-Barr virus) and German measles (rubella) also are causes of myocarditis. Myocarditis is also common in people with HIV, the virus that causes AIDS.
- Bacteria. Numerous bacteria may cause myocarditis, including staphylococcus, streptococcus, the bacteria that causes diphtheria and the tick-borne bacterium responsible for Lyme disease.
- Parasites. Among these are such parasites as Trypanosoma cruzi and toxoplasma, including some that are transmitted by insects and can cause a condition called Chagas' disease. This disease is more prevalent in Central and South America than in the United States, but it can occur in travelers and in immigrants from that part of the world.
- Fungi. Some yeast infections (such as candida), molds (such as aspergillus) and other fungi (such as histoplasma, often found in bird droppings) can sometimes cause myocarditis.
Myocarditis also sometimes occurs if you're exposed to:
- Medications or illegal drugs that may cause an allergic or toxic reaction. These include antibiotics, such as penicillin and sulfonamide drugs, some anti-seizure medications as well as some illegal substances, such as cocaine.
- Other diseases. These include lupus, connective tissue disorders and rare inflammatory conditions, such as Wegener's granulomatosis.
When myocarditis is severe, it can permanently damage your heart muscle. This damage may cause:
- Heart failure. Left untreated, myocarditis can damage your heart's muscle to the point it can no longer pump blood effectively, causing heart failure. In very severe cases, myocarditis-related heart failure requires an artificial heart or heart transplant.
- Heart attack or stroke. If your heart's muscle is injured and can't pump blood, the blood that pools in your heart can form clots. If a clot blocks one of your heart's arteries, you can have a heart attack. If a blood clot in your heart travels to an artery leading to your brain before becoming lodged, you can have a stroke.
- Irregular heartbeats (arrhythmias). Damage to your heart muscle can cause disturbances in your heartbeat (arrhythmias).
- Sudden death. If your heart muscle is so damaged that you develop an arrhythmia, it's possible the arrhythmia could cause your heart to suddenly stop beating (sudden cardiac arrest). If not treated immediately, it causes sudden cardiac death.
There's no specific prevention for myocarditis. However, taking these steps to prevent infections may help:
- Avoid people who have a viral or flu-like illness until they have recovered. If you're sick with viral symptoms, try to avoid exposing others.
- Follow good hygiene. Regular hand-washing is a good way to help prevent spreading illness.
- Avoid risky behaviors. To reduce your chances of getting an HIV-related myocardial infection, practice safe sex and don't use illegal drugs.
- Minimize exposure to ticks. If you spend time in tick-infested areas, wear long-sleeved shirts and long pants to cover as much of your skin as possible. Apply tick or insect repellents that contain DEET.
- Get your immunizations. Stay up to date on the recommended immunizations, including those that protect against rubella and influenza, diseases that can cause myocarditis.