Myocarditis: clinical presentation

Myocarditis has no typical clinical presentation, and may mimic a variety of non-inflammatory myocardial diseases. Cardiac signs and symptoms lack specificity, depending on the degree of myocardial inflammation and ventricular dysfunction, and may be subtle; thus the disease may be unrecognized. Myocarditis may resolve spontaneously, recur, or become chronic leading to dilated cardiomyopathy, sudden or heart failure-related death, or heart transplantation. In 2013, a European Society of Cardiology (ESC) Myocarditis Task Force proposed new criteria for clinically suspected myocarditis, using the combination of a plausible clinical presentation and diagnostic criteria. Importantly, diagnosis requires exclusion of non-inflammatory disease (e.g. coronary artery disease) that could explain specific presentations. The ESC 2013 Task Force also recommended a systematic consideration of endomyocardial biopsy in clinically suspected myocarditis, provided that endomyocardial biopsy includes standard histology, immunohistochemistry, and molecular analysis for infectious agents.