Chang F Y, Lu C L, Chen C Y, Lee S D, Jang H C, Fu S E
Division of Gastroenterology, Veterans General Hospital-Taipei, Taiwan, Republic of China.
Am J Gastroenterol. 1997 Nov;92(11):2090-3.
Clinical knowledge about myoelectrical frequency is well known, but the factors responsible for recorded myoelectrical amplitude remain less clear.
We assembled an electrogastrographic system that could automatically compute the dominant myoelectrical frequency and power and power ratio. We enrolled 50 healthy volunteers (25 men and 25 women) to study their myoelectrical characteristics. Three surface electrodes were placed in the fundic, stomach body, and antral positions for two 30-min recordings in the fasting and postprandial states.
The three different electrodes recorded similar dominant frequencies of about 3 cpm before and after a meal. The fasting dominant powers from these electrodes were 52.9 +/- 14.7, 44.6 +/- 11.5, and 50.1 +/- 15.1 dB, respectively (p < 0.01), whereas the postprandial dominant powers were 61.6 +/- 28.8, 54.3 +/- 26.6, and 61.9 +/- 27.8 dB, respectively (p < 0.01). Meal ingestion did increase the power (p < 0.05). Women had a lower dominant power than men (p < 0.001). Moreover, the dominant powers of each electrode were significantly correlated with body mass index (r = 0.3-0.36, p < 0.05) regardless of meal ingestion. The postprandial power ratio was not influenced by electrode position, gender, or body mass index.
Myoelectrical dominant frequencies and power ratios are similar throughout the whole stomach area, whereas a lower power area exists on the stomach body. Gender-related variation in dominant power seems to be an effect of body size. The power ratio is the only reliable parameter for expressing myoelectrical amplitude.
关于肌电频率的临床知识广为人知，但导致记录的肌电振幅的因素仍不太清楚。
我们组装了一个能自动计算主要肌电频率、功率和功率比的胃电图系统。我们招募了50名健康志愿者（25名男性和25名女性）来研究他们的肌电特征。在空腹和餐后状态下，将三个表面电极分别置于胃底、胃体和胃窦位置进行两次30分钟的记录。
三个不同电极记录的餐前餐后主要频率相似，约为3次/分钟。这些电极的空腹主要功率分别为52.9±14.7、44.6±11.5和50.1±15.1分贝（p<0.01），而餐后主要功率分别为61.6±28.8、54.3±26.6和61.9±27.8分贝（p<0.01）。进食确实增加了功率（p<0.05）。女性的主要功率低于男性（p<0.001）。此外，无论是否进食，每个电极的主要功率与体重指数均显著相关（r = 0.3 - 0.36，p<0.05）。餐后功率比不受电极位置、性别或体重指数的影响。
整个胃区域的肌电主要频率和功率比相似，而胃体存在较低功率区域。主要功率的性别相关差异似乎是体型的影响。功率比是表达肌电振幅的唯一可靠参数。
