Enhanced detection of cardiac myocyte damage by polarized light microscopy: Use in a model of coxsackievirus B3-induced myocarditis

Although accurate detection of cardiac muscle damage is critical in the diagnosis of acute myocarditis or acute cellular rejection in both clinical and experimental settings, the histologic evaluation is frequently uncertain without specialized stains. In a study of adult male A/J mice infected with 2×105 plaque-forming units of myocarditic coxsackievirus B3, cardiac muscle injury causing myofibrillar disruption was detected as a loss of muscle birefringence by polarized light microscopy. The technique was corroborated by comparison with Massonʹs trichrome stain and was helpful for histologic examination especially at the early preinflammatory stages of lesion development or in fringe territories of focal lesions. Polarized light microscopy is thus an available means to enhance the histologic determination of cardiac myocyte damage and has specific advantage in an absence of specialized stains.