Electrical activity of the normal human stomach

Using monopolar electrodes, the gastric electrical activity was recorded in waking human beings from both the mucosal and the serosal sides of the gastric wall. For each electrode location in a given subject, a mean curve of the regular fluctuations in potential (pacesetter potential) was obtained by an iteration process allowing measurement of characteristic amplitudes. A detailed study of the variations of the electrical period within and between subjects was undertaken. The frequency variations of the normal human gastric pacemaker appear in a slow and gradual fashion rather than in irregularities in the period; rhythm disorders rarely occur. Since frequent shifts of the baseline prevent the routine use of DC recordings, the use of a time constant of 4 seconds allows correct reproduction of the second component of the pacesetter potential. The morphology of the pacesetter potential is dependent on the gastric area and on the recording source—ie, mucosal or serosal. The amplitude and slope of the first component are greater in the antrum than in the corpus; the relative amplitudes of the first and the second component are dependent on the recording source.