Fig. 6

Effect of atosiban (i.c.v.) and retosiban (i.v.) on arrhythmia and mortality following acute MI. a A typical ‘Chart’ recording showing an example of arrhythmic episodes within the first minute following LAD coronary occlusion (i.e., myocardial infarction (MI)), and the subsequent increase in cardiac SNA at 180 min post MI. The inset (red box) shows a close-up view of several impulse profiles. b The incidence of arrhythmic episodes (mean ± SEM) each hour for consecutive 3 h following MI in untreated MI rats (Untreated; n = 6), or rats treated with atosiban (MI + atosiban, 4.5 µg in 5 µl i.c.v. n = 6) or retosiban (MI + retosiban, 3 mg/kg, i.v. n = 8). Both atosiban and retosiban significantly reduced the incidence of arrhythmic episodes following acute MI, compared to saline-treated MI rats (*P < 0.05, **P < 0.01, ***P < 0.001, unpaired t-test). c Kaplan–Meier survival analysis showing a greater mortality rate in MI + saline rats (n = 12) compared to MI + retosiban rats (n = 9; P = 0.043) and MI + atosiban rats (n = 7; NS) within 3 h of the MI. None of the sham rats (n = 6) died during the experiment. SNA sympathetic nerve activity