Epidemiology
Etiology
Pathophysiology
Clinical features
- Highly variable presentation, often in a young pt.
- Frequently preceded by a viral prodrome (fever, myalgias, URI Sx).
- Chest Pain: Can be pleuritic (suggesting concomitant pericarditis) or anginal-like.
- Heart Failure Sx: Dyspnea, orthopnea, peripheral edema due to systolic dysfunction.
- Arrhythmias: Palpitations, syncope, or sudden cardiac death (SCD).
- Lyme carditis is notorious for causing AV block.
Diagnostics
- Initial:
- ECG: Sinus tachycardia, arrhythmias, nonspecific ST-T changes. (Diffuse ST-elevation/PR depression if myopericarditis).
- CXR: Often normal; may show cardiomegaly, pulmonary edema, or pleural effusions.
- Key Labs: ↑ Troponin/CK-MB (indicates myocyte necrosis), ↑ ESR/CRP, ↑ BNP/NT-proBNP.
- Echocardiogram: Shows chamber enlargement, global hypokinesis, ↓ LVEF, or pericardial effusion. Helps rule out structural/valvular disease.
- Confirmatory: Cardiac MRI (Best non-invasive test). Shows late gadolinium enhancement (LGE) indicating edema and myocardial scar.
- Gold Standard: Endomyocardial Biopsy (Rarely done). Shows lymphocytic infiltrate w/ myocyte necrosis. Reserved for acute fulminant HF (to r/o Giant cell myocarditis which requires immunosuppression) or failure to respond to standard therapy.
Treatment
Complications