Myocarditis in Children: Symptoms and Causes

Source: Shutterstock

Myocarditis is a condition in which the muscular walls of the heart become inflamed. This results in poor heart function. In most children, myocarditis is triggered by an infection, usually viral, involving the heart.

There are many causes of myocarditis, including:

  • Infection
  • drugs
  • Chemical substances
  • Radiation
  • Some diseases that cause inflammation in many different organs of the body

Age, gender, and genetic makeup can all play a role in the severity of the disease once you have it. Treatment for myocarditis is based on how badly the heart is affected. Many children have a full recovery, but some may develop severe heart failure and require chronic care from a cardiologist.

In this article

  • Myocarditis: the causes
  • Myocarditis: symptoms
  • Myocarditis: the diagnosis
  • Myocarditis: treatments


Read also: Rubella in pregnancy

Myocarditis: the causes

In children, viral infections are the most common causes of myocarditis.

Le infectious causes they can be:

  • Viral 
  • Bacterial 
  • Fungal 
  • parasitic and protozoan 

Le non-infectious causes they can be:

  • Autoimmune 
  • Toxic 
  • Allergic / Hypersensitivity 
  • By physical agents

When myocarditis is caused by an infection, the germ first infects the heart. The germ enters the body and travels through the bloodstream to the heart. It grows and reproduces within the heart. It can cause some cell damage as it spreads from cell to cell.

Normally, the immune system will go to the site of the infection to eliminate the germ. In some children, this response is overly aggressive, so much so that not only the germ is destroyed, but the heart cells themselves can be damaged.

Most heart damage is caused by the body's immune reaction to the germ and not the germ itself. It is not clear why this happens in some children. The abnormal immune response can be limited to a small area or involve a large portion of muscle tissue. Often, the more heart muscle is damaged, the more severe the symptoms. 

Myocarditis can occur, but very rarely, even in children with diseases such as:

  • lupus
  • rheumatoid arthritis
  • ulcerative colitis
  • scleroderma (diseases that involve inflammation of many different organs in the body) 

Myocarditis: symptoms

Clinical experience has shown that the severity of symptoms or disease usually depends on the age of the child.

Children of age over the age of 2 they may have fewer symptoms than infants and children who are usually more severely affected. This is thought to be due to the immaturity of a child's immune system.

  • cold, pale hands and feet: blood does not travel well through the body
  • less urine - your kidneys may also malfunction
  • fever or other signs of infection. In older children, the results are similar, but there may be associated weight loss due to feeding problems.

Older children may have fewer symptoms:

  • fatigue
  • malaise 
  • fever
  • They may not be able to tolerate exercise 
  • complain of chest pain or palpitations (skipped or extra heartbeats)
  • They can develop cough
  • belly pain and nausea due to swelling of the liver.

Due to poor blood flow, the liver and kidneys can be damaged. Early in the disease, the signs and symptoms of myocarditis are subtle so it's easy to go unnoticed.

Myocarditis: the diagnosis

Unfortunately, there is no specific test for myocarditis. This is primarily a clinical diagnosis in which the physician must rely on the family history and physical examination of the child.

There are many tests that can be performed that help make a diagnosis of myocarditis.

  • chest x-ray. Often the size of the heart is enlarged, the blood vessels in the lungs are larger, and fluid can enter the lungs.
  • An electrocardiogram can also provide helpful guidance if the diagnosis is suspected; however, the results may be non-specific. There may also be abnormal heartbeats which can occur with myocarditis.
  • An echocardiogram or cardiac ultrasound can be used to examine the size of the heart and overall function. 
  • Other blood tests can help see how the liver and kidneys are working.
  • A complete blood count and infection-specific tests may also be done.
  • The most accurate way to diagnose myocarditis is to do a cardiac biopsy during a cardiac catheterization. This involves the use of a long catheter that is passed over a large blood vessel in the leg. Once the catheter is in the heart, a tiny piece of heart muscle is taken and sent to the pathologist for examination under a microscope.
    Results vary, but myocarditis is diagnosed with this method up to 65% of the time. The biopsy results are not 100% because the areas of the heart affected by the inflammation are often irregular and may go undetected.

Myocarditis: treatments

Inflammation of the heart muscle usually goes away on its own. There is no cure for myocarditis. In general, the goal of medical therapy is to support cardiac function in order to maintain adequate blood circulation. Most children diagnosed with myocarditis are admitted to an intensive care unit for initial management and careful monitoring.

  • Drugs that help the heart function better, either by controlling blood pressure or by improving the heart's ability to pump blood, are the first line of treatment. One or more of these medicines may be used, depending on the severity of the myocarditis. A diuretic can also help clear excess fluid from the lungs or other body tissues.
  • Medicines may be given to prevent blood clots in the heart. These medicines are used because a clot can form when the heart does not pump efficiently.

Most children diagnosed with myocarditis are admitted to an intensive care unit for initial management. It is important that the baby is put to bed rest. There is evidence to suggest that strenuous activity can be harmful to the heart during the recovery period. Depending on the severity of the myocarditis, this can mean that physical activity is limited for weeks or months. The child's physical activity should be resumed slowly over time.

Article sources: Bambin Gesù Hospital; Cincinnati Childrens; Mayoclinic

  • heart children
  • children's diseases
  • disease
add a comment of Myocarditis in Children: Symptoms and Causes
Comment sent successfully! We will review it in the next few hours.