Myocarditis Masquerading as Ischemic Heart Disease: The Diagnostic Utility of Antimγosin Imaging

Abstract

The diagnosis of myocarditis presents a diagnostic challenge due to its varied clinical presentation. In addition, criteria for myocarditis are varied. At present, the confirmation of myocarditis depends on an endomyocardial biopsy demonstrating myocardial inflammation and necrosis. Unfortunately, this invasive procedure is associated with some degree of risk and has significant limitations. This report discusses the case presentations of two patients with chest pain, electrocardiographic changes and elevated creatine kinase levels suggestive of myocardial infarction, who were subsequently found to have findings compatible with myocarditis based on indium-111 antimyosin antibody scanning. This noninvasive test therefore appears to have value in the differentiation of myocardial ischemia from myocarditis.

Myocardial infarction with normal coronary arteries: a conundrum with multiple aetiologies and variable prognosis: an update

“…Another useful tool to diagnose myocarditis is Indium‐111‐antimyosin antibody scintigraphy [140, 141], which allows the specific detection of myocyte necrosis. In particular, antimyosin antibody scintigraphy appears particularly useful to clarify the diagnosis of myocarditis mimicking AMI [133, 142], as antimyosin antibodies bind specifically to myocardial cells in which the sarcolemma has lost its integrity [143] and myocyte necrosis is an essential component of myocarditis [144]. Moreover, myocyte necrosis in myocarditis is associated with a pattern of antimyosin antibody uptake distinctly different from that of AMI [133], with multifocal myocyte necrosis typically occurring in myocarditis, and therefore diffuse, faint and heterogenous uptake of antimyosin antibodies [133].…”