Kamath, Markad V. and Hollerbach, Stephan and Bajwa, Absar and Fallen, Ernest L. and Upton, Adrian R. M. and Tougas, Gervais (1998) Neurocardiac and cerebral responses evoked by esophageal vago-afferent stimulation in humans: effect of varying intensities. CARDIOVASCULAR RESEARCH, 40 (3). pp. 591-599. ISSN 0008-6363,
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Objective: This study was designed to determine whether esophageal vago-afferent electrostimulation, over a wide range of stimulus intensities, can sustain a cardiac vago-efferent effect by way of central nervous system processing. Methods: Studies were performed in ten healthy male subjects (23.9+/-6.3 years). Esophageal electrostimulation was carried out using a stimulating electrode placed in the distal esophagus. Stimulation of esophageal vago-afferent fibres was employed using electrical impulses (200 mu s at 0.2 Hz x 128 s) varying from 2.7 to 20 mA. Respiratory frequencies, beat-to-beat heart rate autospectra and cerebral evoked potentials were recorded at baseline and at each stimulus intensity in random order. Results: With esophageal electrical stimulation, we observed a small non-significant decrease in heart rate. There was a dramatic shift of the instantaneous heart rate power spectra towards enhanced cardiac vagal modulation with intensities as low as 5 mA. This effect was sustained throughout all intensities with no further change in either the low frequency or high frequency power. Conversely, there was a linear dose response relationship between cerebral evoked potential amplitude and stimulus intensity mainly occurring above perception threshold (10 mA). Esophageal stimulation had no significant effect on heart rate or respiratory frequency at any stimulus intensity. Conclusions:These results indicate that electrical stimulation of the distal esophagus across a wide range of current intensities elicits a reproducible shift in the heart rate power spectrum towards enhanced vagal modulation. The data suggest a closed loop afferent/effepent circuitry wherein tonic visceral afferent impulses appear to elicit a phasic or modulatory vago-efferent cardiac response in healthy subjects. (C) 1998 Elsevier Science B.V. All rights reserved.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | HEART-RATE-VARIABILITY; POSITRON EMISSION TOMOGRAPHY; POWER SPECTRAL-ANALYSIS; ELECTRICAL-STIMULATION; FREQUENCY-DOMAIN; BLOOD-PRESSURE; FLUCTUATIONS; POTENTIALS; DISTENSION; autonomic nervous system; heart rate variability; sinus node; EGG; signal transduction; discipline; clinical |
| Subjects: | 600 Technology > 610 Medical sciences Medicine |
| Divisions: | Medicine > Lehrstuhl für Innere Medizin I |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 21 Feb 2023 06:42 |
| Last Modified: | 21 Feb 2023 06:42 |
| URI: | https://pred.uni-regensburg.de/id/eprint/49276 |
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