What is the definition of Pediatric Myocarditis?

Pediatric myocarditis is inflammation of the heart muscle in an infant or young child.

What are the causes for Pediatric Myocarditis?

Myocarditis is rare in young children. It is slightly more common in older children and adults. It is often worse in newborns and young infants than in children over age 2.

Most cases in children are caused by a virus that reaches the heart. These can include:

  • Influenza (flu) virus
  • Coxsackie virus
  • Parovirus
  • Adenovirus

It may also be caused by bacterial infections such as Lyme disease.

Other causes of pediatric myocarditis include:

  • Allergic reactions to certain medicines
  • Exposure to chemicals in the environment
  • Infections due to fungus or parasites
  • Radiation
  • Some diseases (autoimmune disorders) that cause inflammation throughout the body
  • Some drugs

The heart muscle may be directly damaged by the virus or the bacteria that infect it. The body's immune response can also damage the heart muscle (called the myocardium) in the process of fighting the infection. This can lead to symptoms of heart failure.

What are the symptoms for Pediatric Myocarditis?

Symptoms may be mild at first and hard to detect. Sometimes in newborns and infants, symptoms may appear suddenly.

Symptoms may include:

  • Anxiousness
  • Failure to thrive or poor weight gain
  • Feeding difficulties
  • Fever and other symptoms of infection
  • Listlessness
  • Low urine output (a sign of decreasing kidney function)
  • Pale, cool hands and feet (a sign of poor circulation)
  • Rapid breathing
  • Rapid heart rate

Symptoms in children over age 2 may also include:

  • Belly area pain and nausea
  • Chest pain
  • Cough
  • Fatigue
  • Swelling (edema) in the legs, feet, and face

What are the current treatments for Pediatric Myocarditis?

There is no cure for myocarditis. The heart muscle inflammation will often go away on its own.

The goal of treatment is to support heart function until the inflammation goes away. Many children with this condition are admitted to a hospital. Activity often needs to be limited while the heart is inflamed because it can strain the heart.

Treatment may include:

  • Antibiotics to fight bacterial infection
  • Anti-inflammatory medicines called steroids to control inflammation
  • Intravenous immunoglobulin (IVIG), a medicine made of substances (called antibodies) that the body produces to fight infection, to control the inflammatory process
  • Mechanical support using a machine to help the heart function (in extreme cases)
  • Medicines to treat symptoms of heart failure
  • Medicines to treat abnormal heart rhythms

What is the outlook (prognosis) for Pediatric Myocarditis?

Recovery from myocarditis depends on the cause of the problem and the child's overall health. Most children recover completely with proper treatment. However, some may have permanent heart disease.

Newborns have the highest risk for serious disease and complications (including death) due to myocarditis. In rare cases, severe damage to the heart muscle requires a heart transplant.

What are the possible complications for Pediatric Myocarditis?

Complications may include:

  • Enlargement of the heart that leads to reduced heart function (dilated cardiomyopathy)
  • Heart failure
  • Heart rhythm problems

When should I contact a medical professional for Pediatric Myocarditis?

Call your child's pediatrician if signs or symptoms of this condition occur.

How do I prevent Pediatric Myocarditis?

There is no known prevention. However, prompt testing and treatment may reduce the disease risk.

Myocarditis

REFERENCES

Knowlton KU, Anderson JL, Savoia MC, Oxman MN. Myocarditis and pericarditis. In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 9th ed. Philadelphia, PA: Elsevier; 2020:chap 84.

McNamara DM. Heart failure as a consequence of viral and nonviral myocarditis. In: Felker GM, Mann DL, eds. Heart Failure: A Companion to Braunwald's Heart Disease. 4th ed. Philadelphia, PA: Elsevier; 2020:chap 28.

Parent JJ, Ware SM. Diseases of the myocardium. In: Kliegman RM, St. Geme JW, Blum NJ, Shah SS, Tasker RC, Wilson KM, eds. Nelson Textbook of Pediatrics. 21st ed. Philadelphia, PA: Elsevier; 2020:chap 466.

  • Journal: Giornale italiano di cardiologia (2006)
  • Published —
The last 50 years of pediatric cardiology (1971-2021): from Fontan operation to the present time.
  • Journal: Zhonghua yi xue yi chuan xue za zhi = Zhonghua yixue yichuanxue zazhi = Chinese journal of medical genetics
  • Published —
Analysis of SLC35A2 gene variant in a child with congenital disorder of glycosylation type IIm.