Author + information
- Received July 11, 1983
- Revision received September 26, 1983
- Accepted September 30, 1983
- Published online March 1, 1984.
- David Robertson, MDa,
- Alan S. Hollister, MD, PhD,
- Edmund L. Carey, MD,
- Che-Se Tung, MD PhD,
- Michael R. Goldberg, MD, PhD and
- Rose Marie Robertson, MD, FACC
- ↵aAddress for reprints: David Robertson, MD, Division of Clinical Pharmacology, Vanderbilt University, Nashville, Tennessee 37232.
Responsiveness to the vasopressor, vasodepressor and chronotropic effects of several sympathomimetic amines was assessed in 12 patients with severe autonomic dys-function and in 8 age-matched control subjects. The patients with autonomic dysfunction showed a profound increase in responsiveness to both isoproterenol and phenylephrine as compared with control subjects. The mean bolus dose of isoproterenol required to increase heart rate by 25 beats/min was 0.9 + 0.2 μg in the patients and 5.4 + 2.1 μg in the control subjects. The dose of isoproterenol required to reduce mean blood pressure by 25 mm Hg was 0.3 + 0.2 and 5.2 + 1.8 μg, respectively.
Thus, although there is a 6-fold increase in responsiveness to the chronotropic effect of isoproterenol in autonomic dysfunction, the responsiveness to the drug's depressor effect is increased 17-fold. This enhanced depressor sensitivity is quite marked, even with oral beta-adrenoceptor agonists. Beta-adrenoceptor agonists must be used with caution in conditions associated with autonomic dysfunction if dangerous hypotension is to be avoided.
This study was supported in part by U.S. Public Health Service Research Grants GM 15431, HL 14192 by the Tennessee Affiliate of the American Heart Association, and by the Hrafn Sveinbjarnarson Foundation, Nashville, Tennessee. Dr. Robertson is the recipient of a Research Career Development Award from the National Institutes of Health, Bethesda, Maryland. Dr. Goldberg and Dr. Hollister are Clinical Associate Physicians in the Elliot V. Newman Clinical Research Center, Nashville, Tennessee. Dr. Rose Marie Robertson is an Established Investigator of the American Heart Association. This work was presented at the American Heart Association Meeting in Dallas, Texas, November 1982.
- Received July 11, 1983.
- Revision received September 26, 1983.
- Accepted September 30, 1983.
- American College of Cardiology Foundation