Myocarditis
Also called: Inflammatory cardiomyopathy
Inflammation of the heart muscle, usually triggered by a viral infection. Most cases are mild and recover fully, but it can cause heart failure, dangerous rhythms or sudden death.
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What happens in the body
Viral injury and the immune response damage heart muscle cells, causing swelling, cell death and sometimes scarring.
Causes
- Viruses (enteroviruses, adenovirus, parvovirus B19, influenza, SARS-CoV-2)
- Autoimmune disease (lupus, sarcoidosis)
- Medicines and vaccines (rare, usually mild)
- Toxins, including alcohol and cocaine
Risk factors
- Recent viral illness
- Young adult males
- Autoimmune disease
Symptoms
- Chest pain
- Breathlessness
- Palpitations
- Fatigue
- Recent flu-like illness
Diagnosis — tests and examinations
- Raised troponin
- ECG changes
- Echocardiography
- Cardiac MRI (key test)
- Endomyocardial biopsy in severe or unexplained cases
Treatment
Medicines and medical treatment
- Rest and avoidance of competitive sport for 3–6 months
- Heart failure and arrhythmia medicines as needed
- Immunosuppression for specific types (giant cell, sarcoid)
Operations and procedures
- Mechanical circulatory support in fulminant cases
- Heart transplantation rarely
Self-care, home remedies and lifestyle
- Avoid strenuous exercise until cleared
- Avoid alcohol
Possible complications
- Dilated cardiomyopathy
- Heart failure
- Arrhythmias and sudden death
Prevention
- Vaccination against influenza and COVID-19 lowers risk from those viruses
Outlook
Most mild cases recover completely; severe cases may leave lasting heart weakness.
When to see a doctor
Seek urgent care for chest pain, breathlessness or palpitations after a viral illness.
Sources and further reading
These sources cover this condition. They have not been checked against every statement on this page.
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