Borrelia-like organism in heart capillaries of patient with Lyme-disease seen by electron microscopy.

A case of a patient who developed an acute myocarditis due to Lyme disease is reported. An increased serum antibody titer to Borrelia burgdorferi suggested a diagnosis and in addition of basic clinical methods, endomyocardial biopsy performed and analyzed by transmission electron microscopy. The lumen of myocardial capillaries was founded mostly filled with detritus and fibrin precipitate, between them several bacterial fragments were identified. The electron-microscopic characteristics of the microorganisms in this specimen, revealing irregularly coiled appearance and consistent thickness of 0.2 μm, correspond to the spiral-like structure of Lyme disease borrelia. The presence of fibrin deposits on the capillary endothelium and necrosis of myocardiocytes, suggests that the cardiopathy in our patient was represent borrelia-mediated damage of the heart microcirculation.