Myocarditis: Causes, Symptoms and Treatments

It is a disease that is characterized by inflammation of the heart muscle (myocardium).

Exactly how many people are affected is difficult to know because myocarditis often does not produce symptoms.

The causes

Viral infection is the most common cause of myocarditis.

When you have an infection, the body produces cells to fight the infection. These cells also release chemicals.

If the cells that fight the disease enter the heart they release chemicals that can damage the heart muscle. Your heart can become thick, bloated, and weak.

The search for immediate medical attention to treat infections can help prevent complications. These are some of the types of infections that can cause myocarditis.

Viral infections

  • Virus Coxsackie B.
  • Virus de Epstein-Barr (VEB).
  • El citomegalovirus (CVM).
  • Hepatitis C.
  • Herpes.
  • VIH.
  • Parvovirus.

Bacterial infections

  • Chlamydia (a common sexually transmitted disease)
  • Mycoplasma (bacteria that cause a lung infection)
  • (Streptococcus) streptococcal bacteria
  • (Staphylococci) Staphylococcal bacteria
  • Treponema (the cause of syphilis)
  • Borrelia (the cause of Lyme disease)

Fungal and parasitic infections can also cause myocarditis.


Other causes of myocarditis include certain chemicals or allergic reactions to medications or toxins such as alcohol, drugs, lead, spider bites, wasp stings, or snake bites and chemotherapy and radiation therapy.

Having an autoimmune disease such as lupus or rheumatoid arthritis that causes inflammation throughout the body can also lead to myocarditis.

The signs and symptoms of myocarditis

Myocarditis often does not present symptoms. If you have symptoms, these may include:

  • Difficulty breathing during exercise at first, then at night while lying down.
  • Abnormal heartbeat, which causes fainting in rare cases.
  • Dizziness
  • A pain in the chest is often sharp or throbbing or pressure, which can spread to the neck and shoulders.
  • Fatigue.
  • Signs of infection, such as fever, muscle aches, sore throat, headache or diarrhea.
  • Painful joints
  • Inflammation of the joints, legs or neck veins.
  • Small amounts of urine.


If you have myocarditis, the doctor will treat the underlying cause, also try to take measures to prevent or control complications.

The treatment usually includes medications to help the heart work better. Examples include ACE inhibitors, calcium channel blockers and diuretics.

The doctor is also likely to suggest rest or reduction of activities for at least six months and a low-salt diet to prevent fluid buildup.

You may be hospitalized if you have complications from myocarditis, such as a weakened blood clot or heart. If the abnormal heart rhythms are severe, you may have other medications, a pacemaker or an implantable cardioverter defibrillator (ICD).

Your prognosis depends on the cause of myocarditis, overall health, and if complications develop.

You can recover completely or you can develop a long-lasting chronic condition. It is also important to know that myocarditis can recur, although this is not common.