Pediatric myocarditis is inflammation of the heart muscle in an infant or young child.
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:
It may also be caused by bacterial infections such as Lyme disease.
Other causes of pediatric myocarditis include:
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.
Symptoms may be mild at first and hard to detect. Sometimes in newborns and infants, symptoms may appear suddenly.
Symptoms may include:
Symptoms in children over age 2 may also include:
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:
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.
Complications may include:
Call your child's pediatrician if signs or symptoms of this condition occur.
There is no known prevention. However, prompt testing and treatment may reduce the disease risk.
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.