EFFICIENCY AND EFFICACY OF THE ELECTROGASTROGRAM

The efficiency and efficacy of the electrogastrogram (EGG) involve a f ew practical factors, including recording length, sample size, and the characteristics of subjects. The aim of this study was to investigate the effect of these factors on the accuracy of EGG analysis. Gastric myoelectrical activity was recorded using electrogastrography in 24 su bjects (ages 22-91 years) for 1 hr in the fasting state and 2 hr after a test meal. Computerized spectral analysis was performed to compute EGG parameters, including dominant frequency, dominant power, and the percentage of 2-4 cycles per minute (cpm) slow waves. A parameter call ed misinterpretation was defined to investigate the effect of recordin g length. The results were as follows: (1) Using the recording length of 1 hr in each state as a gold standard, the misinterpretation for th e recording length of 30 min was 27% for the dominant frequency and 17 % for the dominant power. When the recording length was reduced to 15 min, the misinterpretation increased to 61% for the dominant frequency and 38% for the dominant power. (2) With a sample size of 10 subjects and a recording length of 60 min, a statistically significant postpra ndial increase was observed in the dominant frequency and power, and a trend in the postprandial increase of the regularity of the EGG was n oted. When the sample size increased to 24 subjects, a significant pos tprandial increase was found in all these parameters. (3) None of the EGG parameters exhibited any significant difference between the younge r and older subjects or between men and women. In conclusion, a record ing length of 30-60 min seems to be appropriate and produces reliable and predictable results. Age and gender do not affect any of the EGG p arameters.