Myocarditis, Child

Myocarditis is a swelling (inflammation) of the heart muscle (myocardium). There may also be an inflammation of the sac that surrounds the heart (pericarditis). When the heart becomes inflamed, it cannot pump as well. Severe cases of myocarditis can cause heart failure. There are no known risk factors for myocarditis, but the child's age at the time of illness can affect the severity and outcome of the illness.


It can be caused by a viral or bacterial infection.


The symptoms of myocarditis can vary. Children sometimes have a cold or flu-like symptoms 1 to 2 weeks before they develop myocarditis. Infants can have different symptoms.

Common symptoms in infants:

  • High fever associated with:

  • Irritability.

  • Poor appetite or sweating while eating.

  • Fewer wet diapers.

  • Difficulty breathing

  • Bluish or grayish skin color.

  • Cold hands and feet.

Common symptoms in older children:

  • Increased sleepiness (lethargy) associated with:

  • Fever.

  • Difficulty breathing.

  • Chest pain.

  • Passing out.

  • Abdominal pain, feeling sick to the stomach (nauseous), or throwing up (vomiting).

  • Decreased exercise tolerance.


Your caregiver may suspect myocarditis if your child had a recent viral or other type of infection and develops symptoms. A physical exam and other tests may be done. Some tests include:

  • Blood tests to check for infection, heart enzymes, and elecrtrolytes.

  • An electrocardiogram (ECG) to check the electrical patterns and rhythms of the heart.

  • A chest X-ray to look at the heart and lungs.

  • An echocardiogram to see how well the heart is working.

  • Heart (cardiac) catheterization. In this test, a flexible tube (catheter) is inserted into a vein in the leg and is then threaded into the heart. A special instrument can then remove a tiny sample of heart muscle tissue (biopsy). This is sent to a lab for analysis to see if there are signs of inflammation or infection.


  • Mild cases of myocarditis may only need supportive treatment, such as:

  • Antibiotic medicine. These may be given if bacteria is the cause of the inflammation.

  • Bed rest and a balanced diet. Normal activity (or active lifestyle) can worsen the inflammation, and therefore, worsen the heart problems. Once the heart is better, children can slowly return to their normal lifestyle as directed by a heart doctor (cardiologist).

  • Medications may be needed. These medications help keep the heart regular, give the heart more strength, or make it more effective. These can include:

  • Blood pressure medicines to lessen the strain on the heart.

  • Water pills (diuretics) to help the body get rid of excess fluid.

  • An intravenous immunoglobulin (IVIG) drug. It consists of purified antibodies which the body's immune cells produce to fight infection. It slows down the inflammatory process. There may be fewer long-term heart complications in children treated with IVIG.

  • Medications to prevent blood clots in the heart.

  • Hospitalization may be required for severe cases.


  • Understand these instructions.

  • Will watch your condition.

  • Will get help right away if you are not doing well or get worse.