Myocarditis

DEFINITION

Myocarditis is an inflammation of the myocardium, the middle layer of the heart wall. Myocarditis is usually caused by a viral infection. Signs and symptoms of myocarditis include chest pain, heart failure and abnormal heart rhythms.

If myocarditis becomes severe, the pumping action of your heart weakens, and your heart won’t be able to supply the rest of your body with enough blood. Clots also could form in your heart, leading to a stroke or heart attack.

Treatment for myocarditis depends on the underlying cause.

CAUSES

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.

SYMPTOMS

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
• Fatigue

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:

• Fever
• Fainting
• 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.