Histopathological changes in heart.

<p>Sequential histopathological of heart epicardium and the compactum of the ventricle at 4 to 10 weeks post challenge (WPC). All sections are counterstained with hematoxylin and eosin. A) 4 WPC with normal thin, epicardium (E) and normal compact layer (C) of heart ventricle; B) 7 WPC. Infiltration with lymphocytic cells in the epicardium located around small blood vessels (BV); C) 9 WPC. Epicardial infiltration extending into underlying compactum (arrow); D) 10 WPC. Epicardium (right) with infiltration of inflammatory cells along small vascular structures (arrows); E) 9 WPC and focal, infiltration of inflammatory cells in compactum of the heart ventricle; and F) 10 WPC showing myocardial necrosis (arrow) and moderate inflammation. x10 (A) and x40 (B–F), original magnification.