Heart Muscle Inflammation (Myocarditis)

What is myocarditis?

Myocarditis is an inflammation (irritation and swelling) of the muscular walls of the heart. The inflammation may hurt the heart muscle. The heart may weaken and not pump well. The heart may not bring enough blood to the rest of the body.

How does it occur?

Many things can inflame the heart. Causes of myocarditis include:

• infection, most commonly by a virus
• reactions to some drugs, such as doxorubicin and zidovudine (AZT)
• exposure to some chemicals, such as lead, arsenic, and carbon monoxide
• parasites in some parts of Central and South America
• autoimmune diseases (an over-reaction of the body's immune system), such as lupus and rheumatoid arthritis.

What starts the inflammation is not always known. When the cause of myocarditis is not known it is called idiopathic myocarditis.

What are the symptoms?

Sometimes there are no symptoms. When symptoms occur, they are the symptoms of heart failure, such as:

• running out of energy easily
• shortness of breath or trouble breathing, at first during exercise and later with any activity or even when you are resting
• waking up at night with trouble breathing or having a hard time lying flat in bed because of shortness of breath
• swollen ankles and feet and weight gain due to too much fluid in the body.

How is it diagnosed?

Your healthcare provider will ask about your symptoms and examine you. He or she will listen to your heart with a stethoscope.

The first test is usually an echocardiogram (an ultrasound scan of the heart). You may also have blood tests, an electrocardiogram (ECG), or chest X-ray.

You may have a procedure called cardiac catheterization to remove a small piece of heart muscle for tests (a biopsy).

How is it treated?

The goals of treatment are to:

• Relieve inflammation
• Help the heart pump as it heals itself
• Limit damage to the heart muscle

Treatment may include:

• pain relievers
• anti-inflammatory medicines
• heart medicines to control the heartbeat and help the heart pump

Sometimes a device called an intraaortic balloon pump is used to help the heart pump.

If myocarditis is caused by a disease, treating the disease will also treat the heart. For example, if myocarditis is caused by a bacterial infection, antibiotic medicines will be prescribed.

Complications of myocarditis, such as heart failure, can be treated if they occur.

If the heart is severely damaged, you may need a heart transplant.

How can I help take care of myself?

• Eat a healthy diet
• Ask your healthcare provider about physical activity or exercise.
• Talk to your provider before you use any medicines that your provider has not prescribed, including nonprescription medicines and supplements.
• If you smoke, stop.
• Get regular checkups.
• Lose weight if you are overweight.
• Learn ways to reduce or manage stress.
• Cut back on the salt in your diet if recommended by your provider.
• Call your healthcare provider right away if:
  • Your symptoms get worse.
  • You have shortness of breath.
  • You have lightheadness.
  • You have a fast or irregular heartbeat.
  • You have chest pain.

How long do the effects last?

About one-third of people who have had myocarditis return to normal after several weeks to several months. The rest have permanent damage to the heart muscle. The damage can range from slight to severe. In these cases, medicines used for heart failure can help the heart pump better. Sometimes a heart transplant may be considered.