[Myocardial contractility after brain injury]

Cardiac contractile function in the acute period after brain injury (BI) was studied on 158 non-inbred male albino rats, by using the isolated isovolumetrically contracted heart according to the procedure described by Fallen et al. The injured rats showed a significantly depressed left ventricular myocardial contractility during the hypoxic test, followed by reoxygenation, a lower positive chronic inotropic effect, and an increased diastolic defect with an enhanced rate of cardiac stimulation rates. Brain injury increased the dependence of cardiac performance on the concentration of Ca2+ in the perfused solution. The findings suggest the decreased resistance of the hearts of the rats that had sustained BI to pathogenetic factors.