Focal myocardial fibrosis and edema in acute myocarditis demonstrated by multislice computed tomography

Abstract

Endomyocardial biopsy has provided a method for assessing the presence of myocarditis in patients [1,2]. But biopsy studies have produced highly variable results, with the incidence of myocarditis ranging from 0% to 80% [3]. This difference may be due to patient selection [4], differences in diagnostic criteria between studies, and differences between the elapsed time from biopsy to the onset of acute myocarditis. Furthermore, occurrence of focal lesions of myocardium in myocarditis and lack of information regarding such focal lesions during biopsy may contribute to the variations in results. A 34-year-old man presented with chest pain after having a common cold. Electrocardiogram (ECG) revealed ST elevation in all leads except aVR. White blood cell count, creatine phosphokinase and troponin T levels were elevated. Echocardiogram revealed reduced left ventricular wall motion of the apex and inter-ventricular septum (IVS). Conventional coronary angiogram indicated normal coronary arteries and an endomyocardial biopsy from the IVS did not show the typical inflammation or fibrosis, but the diagnosis was acute myocarditis, clinically. To determine the myocardial characteristics, ECG-gated enhanced multislice computed tomography (CT) (Light Speed Ultra, General Electric, Milwaukee, WI, USA) was utilized (slice thickness, 1.25 mm; helical pitch, 3.25). CT scanning was performed with retrospective ECG-gated reconstruction 30 s and 8 min after intravenous injection