Inflammation - heart muscle
Myocarditis is inflammation of the heart muscle.
The condition is called pediatric myocarditis when it occurs in children.
Myocarditis is an uncommon disorder. Most of the time, it is caused by an infection that reaches the heart.
When you have an infection, your immune system produces special cells to fight off disease. If the infection affects your heart, the disease-fighting cells enter the heart. However, the chemicals made by these cells can also damage the heart muscle. As a result, the heart can become thick, swollen, and weak.
Many cases are caused by a virus that reaches the heart. These can include the influenza (flu) virus, coxsackievirus, parovirus, cytomegalovirus, adenovirus, and others.
It may also be caused by bacterial infections such as Lyme disease, streptococcus, mycoplasma, and chlamydia.
Other causes of myocarditis include:
Sometimes the exact cause may not be discovered.
There may be no symptoms. Symptoms may be similar to the flu. If symptoms occur, they may include:
Other symptoms that may occur with this disease:
Types, causes, symptoms, health risks, and treatment of cardiomyopathy.
Myocarditis can be hard to diagnose because the signs and symptoms often mimic those of other heart and lung diseases, or a bad case of the flu.
The health care provider may hear a rapid heartbeat or abnormal heart sounds while listening to the child's chest with a stethoscope. A physical exam may detect fluid in the lungs and swelling in the legs in older children.
There may be signs of infection, including fever and rashes.
Other tests that may be needed include:
Treatment is aimed at the cause of the problem, and may involve:
If the heart muscle is weak, your provider will prescribe medicines to treat heart failure. Abnormal heart rhythms may require the use of other medicines. You may also need a device such as a pacemaker, or implantable cardioverter-defibrillator's to correct an irregular heartbeat. If a blood clot is in the heart chamber, you will also receive blood thinning medicine.
Rarely, a heart transplant may be needed if the heart muscle has become very weak or you have other health problems.
The outcome can vary, depending on the cause of the problem and a person's overall health. Some people may recover completely. Others may have lasting heart failure.
Treat conditions that cause myocarditis promptly to reduce the risk.
Cooper LT, Knowlton KU. Myocarditis. In: Mann DL, Zipes DP, Libby P, Bonow RO, Braunwald E, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 10th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 67.
Knowlton KU, Narezkina A, 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. 8th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 86.
McKenna WJ, Elliott P. Diseases of the myocardium and endocardium. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine. 25th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 60.
Last reviewed on: 2/24/2016
Reviewed by: Michael A. Chen, MD, PhD, Associate Professor of Medicine, Division of Cardiology, Harborview Medical Center, University of Washington Medical School, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.