In vivo Takotsubo Cardiomyopathy model and prevention by Pertussis toxin pretreatment. Contractile responses after an intravenous bolus injection of epinephrine (4.28x10-8 moles.100g-1-dark red bars) on left ventricular apical (A), mid left-ventricular (B) and basal myocardium (C). Values are expressed as the mean percentage change in LV fractional shortening (%∆FS) from baseline (untreated) levels ± SEM at each 5 minute time point following injection. Light blue bars show time-matched inotropic responses of the apical, mid-left ventricular and basal myocardium in PTX (25µg.Kg-1) pre-treated animals after equivalent i.v. epinephrine bolus, with loss of apical and MLV hypokinesis. N=6 (control epinephrine), n=5 (epinephrine+PTX) (**p<0.01, ***p<0.001 vs baseline FS = 0). Abbreviations: B (baseline). RM ANOVA (epinephrine vs epinephrine+PTX): p<0.001 (apex), p<0.01 (MLV), p<0.05 (base); Time: P<0.001 (apex), P<0.001 (MLV), P<0.001 (base).