Objective To determine the frequency of presenting symptoms and the sensitivity of clinical and laboratory investigations routinely available in the emergency department in children with myocarditis.

Methods We performed a retrospective review of patients <18 years who were diagnosed as having myocarditis between May 2000 and May 2006 and who initially presented to an emergency department. Patients were categorized as having definite myocarditis (positive endomyocardial biopsy results) or probable myocarditis (diagnosis assigned by a pediatric cardiologist on the basis of history, physical examination, and investigation results in the absence of an endomyocardial biopsy or in the presence of negative biopsy results).

Results There were 16 cases of definite myocarditis, 15 cases of probable myocarditis. The age distribution was abnormal, with peaks among children < or  = 3 years and > or  = 16 years of age. Of 14 patients who were seen by a physician before being diagnosed with myocarditis, 57% were originally diagnosed as having pneumonia or asthma. 32% of patients presented with predominantly respiratory symptoms, 29% had cardiac symptoms, and 6% had gastrointestinal symptoms. Although evidence of cardiac dysfunction was frequently present in the form of respiratory distress, only a minority of children had evidence of abnormal cardiac examination . The sensitivities of electrocardiograms and chest radiographs as screening tests were 93% and 55%. Among laboratory tests studied, aspartate aminotransferase measurement was the most sensitive (sensitivity: 85%).

Conclusions Children with myocarditis present with various symptoms; respiratory presentations were most common. Aspartate aminotransferase testing may be a useful adjunctive investigation.