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Myocarditis
Myocarditis is inflammation of the heart muscle — usually after a viral infection in a young person — presenting with chest pain, raised troponin and normal coronary arteries; it is confirmed by cardiac MRI, and treatment in most cases is supportive.
Why it matters in the exam
The classic exam scenario is a young patient who had a fever or respiratory infection a few days earlier and now has chest pain, ECG changes and a raised troponin. The question asks for the next test (angiography or coronary CT to exclude coronary disease when needed, then cardiac MRI), and what to advise about exercise — no competitive sport for three to six months, because of the risk of arrhythmias.
Candidates are also asked when to perform an endomyocardial biopsy: fulminant myocarditis with shock, heart failure that does not respond to treatment, advanced conduction block or ventricular tachycardia — especially when giant-cell myocarditis, sarcoidosis or eosinophilic myocarditis is suspected, which are treated with immunosuppression. Myocarditis after mRNA vaccination (young people, usually mild), myocarditis from immune checkpoint inhibitors in cancer treatment (treated with high-dose steroids) and Chagas disease also appear.
The prognosis is good in most cases, but some patients develop dilated cardiomyopathy, so they remain under echo follow-up. A patient with heart failure receives the standard heart-failure treatment.
Key points
- Young patient, viral infection, chest pain and raised troponin with normal coronaries — myocarditis.
- The diagnosis is made by cardiac MRI: oedema and non-ischaemic enhancement.
- Biopsy in severe cases: shock, refractory failure, advanced block, VT.
- Supportive treatment; immunosuppression only in certain types (giant cell, sarcoidosis, eosinophilic, checkpoint inhibitors).
- No competitive sport for 3–6 months.
Summary table
| Item | The rule | Details | Note |
|---|---|---|---|
| Presentation | Chest pain, breathlessness, palpitations, after a viral infection | Raised troponin, ST changes, arrhythmias | Normal coronary arteries |
| Diagnosis | Cardiac MRI | Myocardial oedema and non-ischaemic late enhancement (subepicardial or mid-wall) | Exclude coronary disease according to age and risk |
| Biopsy | Fulminant, refractory heart failure, advanced block, VT | Giant-cell myocarditis, sarcoidosis, eosinophilic | These are treated with immunosuppression |
| Treatment | Supportive; treat heart failure and arrhythmias | In shock — mechanical support | No competitive activity |
| Special cases | Immune checkpoint inhibitors | High-dose steroids | Dangerous disease with high mortality |
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Sources
- ESC Guidelines for the management of myocarditis and pericarditis, 2025 — Diagnosis, cardiac magnetic resonance, endomyocardial biopsy and treatment
- Harrison's Principles of Internal Medicine, 21st edition (2022) — Myocarditis and Other Myocardial Diseases
Sources are given for further reading; the text is written afresh and not copied from them.
Reviewed by the Examqo AI Professor · 2026-11-02. The text may contain errors; when in doubt, check the source.