REPRODUCIBILITY OF MULTICHANNEL ELECTROGASTROGRAPHY PARAMETERS IN DYSPEPTIC PATIENTS AND HEALTHY CONTROLS

Background and aim: A growing interest has arisen about electrogastrography (EGG) as a non invasive tool to assess gastric function. However, only few studies have attempted to assess reproducibility of this technique, with inconsistent results because of the different techniques and the small number of studied subjects. The aim of this study was to verify the reproducibility of multichannel cutaneous EGG in healthy and in dyspeptic subjects.Material and methods: A total of 30 dyspeptic patients (12 M, age 21-40 years, BMI 22 ± 5) and 10 age and sex matched healthy controls were enrolled. All subjects underwent two successive examinations involving a 30-min fasted 4–leads surface recording, followed by a 60-min postprandial registration after intake of a 480-kcal solid test meal. Parameters considered were dominant frequency, percentage of normal rhythm, the dominant frequency instability coefficient (DFIC) and power ratio. All measures refers only to lead positioned on the abdominal projection of gastric pace-maker. Data (mean ± SEM) were compared by using the paired t test, and individual variability was expressed as the percent coefficient of variation (CV%). Results: In healthy subjects, the dominant frequency was highly reproducible (p > 0.05), with similar coefficient of variation during fasting and postprandial (8% and 15% respectively). Percentage of normal rhythm also showed a low variability (p > 0.05; CV of 20% and 11% in fasting and postprandial session respectively). DFIC and power ratio, conversely, showed a high degree of variability. Similarly, in patients, the dominant frequency was highly repro- ducible (p > 0.05), with CV of 5% both in fasting and postprandial period and percentage of normal rhythm was also quite reproducible, with CV of 19% and 21% in fasting and postprandial phase respectively. DFIC and power ratio showed a higher degree of variability also in patients. Conclusions: Both in dyspeptic patients and in healthy control subjects, gastric myoelectrical activity, quantified by multichannel electrogastrography, shows good reproducibility during both fasting and postprandial state. The most reproducible parameters are the dominant frequency and, to a lesser extent, the percentage of normogastria. The good reliability makes EGG an ideal tool to noninvasively study gastric myoelectrical function.