Myocarditis: Inflammation of the myocardium , the heart muscle. It can be caused by a number of different conditions. The most common cause is infection of the heart muscle by a virus The virus causes the initial heart muscle inflammation. After the initial viral infection subsides, the body’s immune system continues to inflict inflammatory damage on the heart muscles, prolonging the myocarditis, a process termed auto immunity. Other causes of myocarditis include such as a disease called sarcoidosis, various auto immune diseases such as systemic lupus, and certain drugs.
What causes myocarditis?
The causative agents that damage myocardium include the following:
- Cytotoxic effects of infecting agents like viruses, bacteria fungi, and/or parasites
- Immune response triggered by infecting agents and cytokines produced in the myocardium in response to infection or inflammation
- Chemicals released during myocardial cell death
- Autoimmune responses can also trigger myocardial inflammation
- Some medications and/or toxins such as clozapine, radiation therapy, arsenic, carbon monoxide, and many others
- Certain diseases like lupus, Wegener’s granulomatosis, and others
About half of the time, the triggering agent for myocardial inflammation is not known (idiopathic). This is especially true in pediatric population where the majority of patients are diagnosed with idiopathic myocarditis.
Symptoms
It can be mild and cause virtually no noticeable symptoms. The most frequent symptom is pain in chest. Other symptoms are related to the underlying triggering cause, like infection or an autoimmune disorder. The following is a list of symptoms and signs:
- Chest discomfort
- Shortness of breath
- Swelling and/or edema
- Liver congestion
- Abnormal heartbeat (palpitations)
- Sudden death (in young adults)
- Fever (usually associated with an infectious process)
Myocarditis in children and infants has more nonspecific symptoms:
- Malaise
- Poor appetite
- Abdominal pain
- Chronic cough
- Increasing difficulty breathing
- Fever
- Rash
- Diarrhea
- Joint pain
Treatment
Often, myocarditis improves on its own without treatment with complete recovery. Sometimes, treatment of the underlying cause (such as bacterial infection) can lead to complete recovery (for example, after antibiotics). Consequently, the diagnosis of the precise underlying cause of myocarditis can help in the optimal choice of treatment.
However, in patients with more prolonged or more severe cases, individuals may need more specific medications or even hospitalization. Medications to reduce the heart’s workload and/or reduce edema are commonly used to treat symptoms of myocarditis.
Individuals with severe symptoms(heart failure, acute shortness of breath) may require other treatments such as IV medications and/or vascular assist devices (pumps that help a weak heart pump) or extracorporeal membrane oxygenation (ECMO) to help provide oxygen to the blood. Occasionally, patients may require a heart transplant. Individuals who develop very irregular heartbeats (arrhythmias) may need an implanted pacemaker.