2.4. Histopathological Evaluation of the Cardiac Damage

Cardiac specimens were fixed in 10% neutral-buffered formalin, embedded in paraffin, sectioned at 5 μm thickness, and stained with hematoxylin and eosin. A modified scoring system was done according to Li et al. [14] and Moreno Júnior et al. [27]. Ten fields of vision for each group were selected. Histological changes such as necrosis of myofibers, hemorrhage, and inflammatory cell infiltration were scored on a 4-point scale: (-) negative, indicating no necrotic foci; (+) mild, indicating one or two small foci of myocardial necrosis, with scattered areas of hemorrhage and a slight degree of inflammatory process; (++) moderate, indicating more than two areas of small foci of myocardial necrosis, with a few areas of hemorrhage and a diffuse inflammatory process; and (+++) severe damage, indicating confluent foci of myocardial necrosis, with many areas of hemorrhage and massive areas of inflammation.