Cardiac magnetic resonance imaging: diagnostic value and utility in the follow-up of patients with acute myocarditis mimicking myocardial infarction

Abstract

The aim of our study was to evaluate the efficacy of magnetic resonance imaging (MRI) in the differential diagnosis between active myocarditis and myocardial infarction in patients with clinical symptoms mimicking acute myocardial infarction. Between 1 January 2006 and 30 June 2007, 23 consecutive patients (21 men and 2 women) presenting with electrocardiographic abnormalities mimicking acute myocardial infarction and a clinical suspicion of acute myocarditis (fever, chest pain and elevated troponin levels) underwent contrast-enhanced cardiac MRI within a week of admission. All patients also underwent coronary angiography, which demonstrated the absence of significant coronary artery lesions. The mean follow-up period was 2+/-4 months. Cardiac MRI with injection of contrast material showed late subepicardial and intramyocardial enhancement in all patients. Subendocardial late enhancement, a typical pattern of myocardial infarction, was never seen. In addition, in agreement with the literature, there was prevalent involvement of the lateral segments of the left ventricular wall. Cardiac MRI could be a valuable tool for the early diagnosis of acute myocarditis, as it can demonstrate specific patterns that help rule out acute myocardial infarction.