[Effect of adaptation to continuous stress on the contractile function and electric stability of the heart]

In the time course of 15-day stress of moderate intensity, rat experiments indicated that following a day there developed a complex of changes typical of acute stressor syndrome. Five days of post-stress , the stress-related cardiac syndrome ceased, bradycardia developed, the contractile function was limited, and the fibrillation threshold returned to the control values, which was shown to be associated with activation of the cholinergic stress-limiting system. Fifteen days later there was normalization of heart rate and cardiac contractility, the fibrillation threshold remained at the baseline level.