Effect of high-frequency gastric electrical stimulation on gastric myoelectric activity in gastroparetic patients.

The aim of this study was to investigate the effect of gastric electrical stimulation (GES) on gastric myoelectric activity (GMA) and to identify possible mechanisms that could help explain how high-frequency GES is effective in treating nausea and vomiting associated with gastroparesis. Fifteen gastroparetic patients who received high-frequency GES were enrolled. Two pairs of temporary pacing wires were implanted on the serosa of the stomach along the greater curvature during surgery for placement of the permanent stimulation device. Two-channel serosal recordings of GMA before and during GES were measured. A gastric emptying test and severity of nausea and vomiting were assessed at baseline and at 3 months of GES. Power spectral and cross correlation analyses revealed that impaired propagation of slow waves (50%), tachygastria (30%) and abnormal myoelectric responses to a meal (50%) were the main abnormalities observed at baseline. GES with a high frequency significantly enhanced the slow wave amplitude and propagation velocity, and resulted in a significant improvement in nausea and vomiting but did not entrain the gastric slow wave or improve gastric emptying after 3 months of GES.