Assessment of autonomic pathways through esophageal stimulation

The authors studied the effects of esophageal electrical stimulation on heart rate variability power spectra and cortical evoked potentials (EPs) in healthy subjects. In the first study they stimulated the esophagus of 15 healthy subjects at 20 mA using 200 /spl mu/s wide pulses at frequencies from 0.1 Hz to 1 Hz. For the second study they stimulated the esophagus of 13 volunteers at currents from 2-20 mA and at 6/minute. For both studies the LF:HF ratio decreased significantly during stimulation when compared to resting levels. In the second study, the amplitude of the principal wave (P2) of the EP increased with the stimulus intensity. The authors' studies suggest that esophageal stimulation can permit one to access neural pathways of the autonomic nervous system.