Evaluation of gastric emptying by electrogastrography and ultrasonography in gastroesophageal reflux disease

Background: It has been suggested that transient lower esophageal sphincter relaxation is involved in the occurrence of gastroesophageal reflux disease (GERD) and that decreased gastric emptying is an exacerbating factor of transient LES relaxation. In addition, the gastric emptying function is considered to be closely related to gastric motility. Methods: Gastric activity was evaluated by electrogastrography (EGG) in 22 patients with endoscopically positive reflux esophagitis (15 with mild esophagitis of Los Angeles grade A or B and seven with severe esophagitis of Los Angeles grade C or D) and 20 normal individuals. The gastric emptying function was also evaluated by abdominal ultrasonography. The sampling cycle of EGG was 1 s, and the measured frequency was 2.1–6.0 cycle/min (c.p.m.). The mean amplitude of EGG was compared by EGG spectral analysis among brady-gastria cases with a contraction frequency of less than 2.4 c.p.m., normo-gastria cases with a contraction frequency of 2.4–3.6 c.p.m., and tachy-gastria cases with a contraction frequency exceeding 3.6 c.p.m. Results: In the patients with GERD, both the frequency of 3-c.p.m. waves and peak frequency were reduced, and the gastric emptying function examined by ultrasonography had deteriorated, in comparison with normal individuals. Of those with GERD, the ultrasonographic gastric emptying function was significantly reduced in all patients with severe esophagitis compared with those with mild esophagitis, but the differences of the frequency of 3-c.p.m. waves, the peak frequency, were not significant. Also, no significant difference was observed in the frequency of 3-c.p.m. waves or the ultrasonographic gastric emptying function between the 16 patients with hiatal hernia and the six patients with no hiatal hernia. However, the mean amplitude in brady-gastria and tachy-gastria was significantly increased in the patients with hiatal hernia compared to those without hiatal hernia. Conclusions: Reduced gastric motility was suggested to be involved in the development of reflux esophagitis, and the presence of hiatal hernia was considered to have some effect on gastric motility.