Multichannel electrogastrography under a magnifying glass - an in-depth study on reproducibility of fed state electrogastrograms

We checked on reproducibility of parameters of a multichannel electrogastrogram in adults after intake of typical, applied in electrogastrography, test meals. Recordings of multichannel electrogastrograms were accomplished in four blocks comprising 18 subjects (nine healthy volunteers and nine patients with functional GI disorders) each. Every subject had two examinations taken 1-2 days apart, and a third one was accomplished at least 2 weeks before or after the two other sessions. The registration involved a 30-min fasted and a 2-h postprandial period after one of the meal stimuli tested within a given block: 400 mL water, 400 g yoghurt (378 kcal), a scrambled eggs sandwich (370 kcal), a pancake (355 kcal). From among the parameters reflecting the propagation of the gastric slow waves, the average percentage of slow wave coupling (APSWC) exhibited a good (coefficient of variation for paired examinations CVp <= 10%) to moderate (10 < CVp <= 30%) reproducibility. On the other hand, the reproducibility of the maximum dominant frequency difference and the spatial dominant power difference was found to be unsatisfactory. The reproducibility of the multichannel electrogastrographic parameters did not differ between healthy volunteers and patients with functional GI disorders. Gender or the kind of a test meal did not affect the reproducibility of the electrogastrographic parameters either. The medium-term reproducibility was not any worse than the short-term one. From among the parameters of a multichannel electrogastrogram intended to quantify the propagation of slow waves, only the APSWC offers a reproducibility potentially good enough for clinical applications.