Myocarditis is inflammation of the heart muscle, most often after a viral infection and less often from drugs, autoimmune disease or, rarely, mRNA vaccines in young men. It ranges from mild chest pain to heart failure, dangerous arrhythmias and sudden death.
Key symptoms
- Chest pain, often after a recent viral illness
- Shortness of breath and fatigue
- Palpitations or fainting
- Fever, muscle aches or recent cold or stomach symptoms
What you find on exam
- Heart rate faster than the fever explains
- S3, crackles, raised jugular venous pressure or edema
- Pericardial rub if the pericardium is also inflamed
- Low blood pressure or cool limbs in severe cases
Tests
- Troponin, often raised, and CRP
- ECG: ST and T wave changes, arrhythmias, conduction block
- Echocardiogram for pump function and wall motion
- Cardiac MRI to confirm inflammation; coronary imaging to rule out a heart attack
Treatment basics
- Supportive care with heart monitoring
- Heart failure therapy: diuretic, ACE inhibitor and beta blocker as tolerated
- Avoid NSAIDs; no competitive sports for 3 to 6 months
- Mechanical support or transplant referral if fulminant; steroids for giant cell or autoimmune forms
Red flags
- Low blood pressure or cardiogenic shock
- Ventricular arrhythmia or fainting
- Rapidly falling ejection fraction
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Sources: NCCPA PANCE Content Blueprint; NBOME COMLEX-USA clinical presentations; AAMC Core Entrustable Professional Activities (Core EPAs). Written by Making Synapses. Making Synapses is not affiliated with these organizations.