The diagnosis of myocarditis is complex. The ECG is a widely used screening tool despite low sensitivity; findings vary from nonspecific T-wave and ST-segment changes to ST-segment elevation mimicking an acute myocardial infarction.
Cardiac biomarkers lack specificity, but may help to confirm the diagnosis of myocarditis; higher levels of troponin T have been shown to be of prognostic value by predicting M&M.
Cardiovascular magnetic resonance (CMR) has evolved as a noninvasive and valuable clinical tool for the diagnosis of myocarditis. The initial changes in myocardial tissue during the first phase of myocardial inflammation represents an attractive target for successful CMR-based imaging diagnosis. The gold standard is endomyocardial biopsy (EMB). The Dallas criteria defines acute myocarditis by lymphocytic infiltrates associated w/ necrosis.
The prognosis ranges from full recovery, development of dilated cardiomyopathy, or death.
Tx strategies remain limited to standard heart failure therapy and supportive therapy. Immunomodulating and immunosuppressive therapy have been effective, particularly in a single-center trial (TIMIC study) in chronic virus-negative inflammatory cardiomyopathy. Immunosuppression therapy is also beneficial for acute giant cell myocarditis, sarcoidosis, and autoimmune diseases, such as lupus carditis.
Kindermann I, Barth C, Mahfoud F, et al. Update on Myocarditis. JACC:59;9 Feb 28, 2012.