The authors wish to acknowledge the valuable advice of Charles Berry, J. Richard Jennings, Matthew Levy, Benjamin Natelson, Joseph Sapira, and Michael Ziegler.
Effects of Isoproterenol on T-Wave Amplitude and Heart Rate: A Dose-Response Study
Version of Record online: 30 JAN 2007
Volume 28, Issue 4, pages 458–462, July 1991
How to Cite
Contrada, R. J., Dimsdale, J., Levy, L. and Weiss, T. (1991), Effects of Isoproterenol on T-Wave Amplitude and Heart Rate: A Dose-Response Study. Psychophysiology, 28: 458–462. doi: 10.1111/j.1469-8986.1991.tb00731.x
Preparation of this article was assisted by NIH grants HL36005 and M01-RR00827.
- Issue online: 30 JAN 2007
- Version of Record online: 30 JAN 2007
- (Manuscript received January 5, 1990; accepted for publication August 13, 1990)
- T-wave amplitude;
- Heart rate;
- Beta-adrenergic activity;
- Sympathetic activity
This report examines the hypothesis that electrocardiographic T-wave amplitude is sensitive to graded increases in beta-sympathetic stimulation of the heart. Beta-adrenergic activity was manipulated pharmacologically in 9 healthy men by bolus infusion of isoproterenol in each of six doses: 0.1, 0.25, 0.5, 1.0, 2.0, and 4.0 micrograms. Results indicated that elevations in heart rate above placebo values increased as a linear function of isoproterenol dose. In contrast, the dose-response curve for T-wave amplitude was best described by a quadratic function: An initial reduction in T-wave amplitude at low levels of isoproterenol infusion was followed by a significant reversal of this effect at higher doses. Comparison of the heart rate and T-wave amplitude data points to limitations in the use of the latter as an index of beta-adrenergic activity. One of several possible explanations for the T-wave results would entail a mechanism that preserves ventricular function at high levels of beta-sympathetic stimulation.