SEROSAL AND CUTANEOUS RECORDINGS OF GASTRIC MYOELECTRICAL ACTIVITY INPATIENTS WITH GASTROPARESIS

Serosal and cutaneous recordings of gastric myoelectrical activity in patients with gastroparesis. Am. J. Physiol. 266 (Gastrointest. Liver Physiol. 29): G90-G98, 1994.-The aims of this study were to 1) investi gate gastric myoelectrical activity in patients with gastroparesis, 2) validate the cutaneous electrogastrogram (EGG) in tracking the freque ncy change of the gastric slow wave, and 3) investigate the effect of electrical stimulation on gastric myoelectrical activity. Gastric myoe lectrical activity was recorded in 12 patients with documented gastrop aresis using serosal electrodes for > 200 min in each subject. All rec ordings were made at least 4 days after surgery. Each session consiste d of a 30-min recording in the fasting state and a 30-min recording af ter a test meal. The test meal (liquid or mixed) was selected accordin g to patient's tolerance. Electrical stimulation was performed in thre e subjects via the serosal electrodes at a frequency of 3 cycles/min. Gastric myoelectrical activity was recorded using serosal electrodes i n each session. The serosal recording showed slow waves of 2.5 to 4.0 cycles/min in all 12 subjects. Absence of spikes was noted in 11 of th e 12 subjects. The simultaneous serosal and cutaneous recording of gas tric myoelectrical activity showed that the frequency of the EGG was e xactly the same as that of the serosal recording. Liquid meals resulte d in a significant decrease in slow-wave frequency (Student's t test, P = 0.006), and the EGG accurately reflected this change. Electrical s timulation had no effect on the frequency of the gastric slow wave and did not induce spikes. It was concluded that 1) the absence of spike activity was the main abnormality observed in these gastroenteric pati ents, 2) the EGG accurately reflected the frequency of the gastric slo w wave and was able to detect changes induced by the test meal, and 3) electrical stimulation in patients with gastroparesis at the physiolo gical frequency of 3 cycles/min may not have any effect on gastric myo electrical activity.