24-HOUR AMBULATORY ELECTROGASTROGRAPHY IN HEALTHY-VOLUNTEERS

Background: Development of electrogastrography, the recording of gastr ic electric rhythm from cutaneous electrodes, for clinical purposes ha s been hampered by methodologic problems and the lack of an ambulatory technique. We have evaluated a newly developed system for ambulatory electrogastrography. Methods: 24-Hour recordings were obtained from 30 healthy volunteers. We used digital filtering, a Hamming window, and spectral analysis to determine the dominant frequency of successive 25 6-sec segments of data. Results: Low-frequency noise disturbed the pri mary signal. After secondary filtering a stable normogastric (2-4 cpm) rhythm was present during a median of 49% (range, 34-79%) of the reco rding time. The mean frequency of gastric electric activity varied fro m 2.92 +/- 0.15 cpm (mean +/- SD) at mid-day to 2.72 +/- 0.13 cpm in t he late night. Conclusions: Ambulatory recording of electrogastrograph y needs technical improvement. The electrogastrogram shows a circadian variation infrequency.