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Critical Reviews™ in Biomedical Engineering

ISSN for PRINT: 0278-940X

Institutional price:	$1677.00
Issues per year:	6

Best Paper Award Selection - Editorial Board Site

2000, Volume28

356 pages

Issue price - $532.00

Effects of Esophageal Stimulation in Healthy Subjects

Markad V. Kamath
McMaster University

Andrew May
Departments of Medicine and Electrical and Computer Engineering, HSC 3E 25, McMaster University, 1200 Main Street West, Hamilton, Ontario, L8N 3Z5, Canada

Stephan Hollerbach
Ruhr-Universitaet of Bochum, Bochum, Germany

Debbie Fitzpatrick
Departments of Medicine and Electrical and Computer Engineering, HSC 3E 25, McMaster University, 1200 Main Street West, Hamilton, Ontario, L8N 3Z5, Canada

Absar Bajwa
Departments of Medicine and Electrical and Computer Engineering, HSC 3E 25, McMaster University, 1200 Main Street West, Hamilton, Ontario, L8N 3Z5, Canada

Gervais Tougas
Departments of Medicine and Electrical and Computer Engineering, HSC 3E 25, McMaster University, 1200 Main Street West, Hamilton, Ontario, L8N 3Z5, Canada

Ernest L. Fallen
Departments of Medicine and Electrical and Computer Engineering, HSC 3E 25, McMaster University, 1200 Main Street West, Hamilton, Ontario, L8N 3Z5, Canada

Glen Shine
Departments of Medicine and Electrical and Computer Engineering, HSC 3E 25, McMaster University, 1200 Main Street West, Hamilton, Ontario, L8N 3Z5, Canada

Adrian R. Upton
Departments of Medicine and Electrical and Computer Engineering, HSC 3E 25, McMaster University, 1200 Main Street West, Hamilton, Ontario, L8N 3Z5, Canada

ABSTRACT

We studied the effects of esophageal electrical stimulation on heart rate variability power spectra (PS/HRV) and cortical evoked potentials (EPs) in healthy subjects. The intensity of stimulation was varied from 2.7 to 20 mA. We found that the amplitude of the cortical evoked potentials (amplitude of the N₂/P₂ peak) increased from 5.1 ± 0.7 mV at 5 mA to 16.3 ± 1.1 mV at 20 mA. The PS/HRV showed an increase in the vagal modulation of the sinus node. When the stimulation frequency was varied from 0.1 to 1 Hz at a constant intensity of 15 mA, the amplitude of cortical EPs (N₂/P₂ peak) decreased with increase in the frequency of stimulation (p < 0.05). The LF:HF ratio decreased significantly for all frequencies of stimulation (p < 0.005). An experimental paradigm to evoke the cognitive component in the cortical EPs yielded a peak around 354 ms following the stimulus.