Role of electrogastrography and gastric impedance measurements in evaluation of gastric emptying and motility.

Electrogastrography records electrical potential variations brought about by myoelectrical activity of the stomach. Abnormal myoelectrical rhythms such as tachygastrias may also be detected. Electrogastrography provides little information on gastric motility and emptying. Impedance epigastrography is a technique that uses changes in epigastric impedance to evaluate gastric emptying of large-volume liquid meals. The results are inferior to those of tomographic impedance imaging. Phasic antral contractions may lead to phasic impedance changes recorded with nonimaging techniques and a phasic signal recorded with high-speed electrical impedance tomography. However, the relationship between phasic contractions and phasic variations in impedance do not appear consistent enough to allow clinical application of the technique.