[Adrenalin and cardiac output in pregnancy (author's transl)]

The heart rate performance, cardiac output and catecholamine excretion were observed at rest in the ergometer test (40 min at 50 watts) in a group of 8 pregnant women whose case history and clinical record did not reveal any abnormal findings, during the course of pregnancy (20th, 28th and 36th weeks of pregnancy) as well as 2 and 12 weeks post partum. It was found that the cardiac output increased, dependent upon the heart rate, the stroke volume remaining approximately constant (max. + 60%) during pregnancy, compared with the controls post partum. There is a close linear correlation (r = 0.983) between the measured heart rates and the corresponding excretion of epinephrine (adrenalin) with the urine at rest and under load. It may be assumed that there is a causative link between the increase in secretion of catecholamine by the mother and the well-known change in cardiac output during pregnancy.