Figure 1: Histological Characterization of Mid-Heart Sections of Control Rats and From Rats After Induction of Takotsubo Cardiomyopathy

Histological characterization of hematoxylin and eosin–stained mid-heart sections of control rats and from rats over the time course (0 to 14 days) after induction of takotsubo cardiomyopathy show a temporal immune/inflammatory cellular infiltrate. Sections of heart tissue were semiquantitatively scored by a consultant histopathologist (K.K.) blinded to the study. Arbitrary scores of 0, 1, and 2 were given for (A) hemorrhage (gray bars) or presence of hemosiderin-containing phagocytic cells (white bars), (B) immune/inflammatory cellular infiltrates, (C) degenerate myofibrils/myofiber atrophy, and (D) eosinophilic myofibers. The number of animals per group were as follows; control n = 7, day 1 n = 6, day 2 n = 6, day 3 n = 7, day 4 n = 6, day 5 n = 7, day 6 n = 6, day 7 n = 5, and day 14 n = 5 animals. Statistical difference in histological scores between control rats and those injected with isoprenaline were calculated with p values denoted above each time point bar. Values in bold indicate statistically significant differences compared with the control group.