[Cardiovascular instability in schizophrenic patients may be caused by alpha 1-blocking activity of major...

In order to prove the hypothesis that cardiovascular instability of schizophrenic patients is caused by alpha 1-blocking effect of major tranquilizer, we measured the blood pressure (BP), the heart rate (HR), and serum epinephrine and norepinephrine levels before and after isometric handgrip (IHG) test in schizophrenic patients and normal adults (control). The results were as follow: (1) In schizophrenic patients systolic BP rose significantly less than in controls after IHG test. (2) HR in patient group was constantly higher than in control group. (3) Though HR after IGH test decreased in normal group, there was no significant difference in HR before and after IHG test in patient group. (4) In patient group, norepinephrine level was higher than in control group before IHG test but it did not increase after IHG test, while it did increase in normal group. It is concluded that alpha 1-receptors are selectively blocked and the reactivity to norepinephrine is reduced in schizophrenic patients who has been taking a major tranquilizer. This results in the impairment of the ability to control immediately BP corresponding to postural change and to exercise, which probably causes instability in circulatory state in schizophrenic patients under general anesthesia.