The hemodynamic effects of intravenously administered Ko 1366 were studied in old normotensive and hypertensive subjects at resting supine position and compared with the effects of propranolol.
Rate of change in cardiac index (CI) and stroke volume index (SVI) was slightly less by Kö1366 in normotensive and hypertensive subjects than that by propranolol.
In the subjects with normal CI among normotensive subjects, the decrease in CI by K6 1366 was lower than that by propranolol. Moreover, in the subjects with lower CI, CI and SVI increased by Kö1366.
In the subjects with higher CI among hypertensive subjects, the rate of change in CI and SVI showed a tendency to decrease slightly by Ko 1366 than that by propranolol. However, in the subjects with normal CI, the rate of change in CI and SVI by Kö1366 was not significantly different when compared with that by propranolol. In the subjects without electrocardiographic changes of left ventricular hypertrophy among hypertensive subjects, SVI showed a tendency to increase by Kö 1366, while it decreased by propranolol. In the subjects with electrocardiographic changes, both CI and SVI increased by Kö1366, whereas they decreased by propranolol.
These results suggested that the intrinsic sympathomimetic activity of Kö1366 manifested when cardiac function of old subjects was depressed. This could be the advantage of Kö1366 over propranolol in the treatment of old subjects with cardiac disease.