Clinical Applications of Electrogastrography

Abstract

Electrogastrography methods have been used in many clinical studies over the past 80 years. In 1922,Alvarez predicated that electrical abnormalities of the stomach may be related to gastrointestinal (GI) symptoms and abnormal gastric function. In 1980, antral dysrhythmias were recorded with mucosal electrodes in a series of patients with unexplained nausea and vomiting. These gastric dysrhythmias were 6— to 7—cycles per minute (cpm) tachygastrias, bu there were also very irregular rhythms that changed from bradygastria to tachygastria (mixed dysrhythmias or tachyarrhythmias). Bradygastrias also were recorded in patients with unexplained nausea and vomiting. Further studies showed a relationship between the presence of nausea and gastric dysrhythmias during motion sickness, in nausea and vomiting of pregnancy, and in patients with idiopathic and diabetic gastroparesis. Infusion of a variety of drugs and physical distention of the antrum also induced gastric dysrhythmias and symptoms of nausea. Ischemic gastroparesis with gastric dysrhythmias due to chronic mesenteric ischemia is an unusual cause of chronic nausea and vomiting. Ischemic gastroparesis is important to recognize because after revascularization the symptoms resolved, the gastric dysrhythmias were eradicated and normal 3-cpm EGG activity and normal gastric emptying were restored. Thus, gastric dysrhythmias are found in many disorders in which nausea and vomiting are prominent symptoms. Clinical conditions associated with gastric dysrhythmias were reviewed. Finally, a variety of drugs and nondrug therapies convert gastric dysrhythmias to normal 3-cpm gastric myoelectrical rhythms and the correction of the gastric dysrhythmia correlates with improvement in symptoms. Taken together, these findings indicate that gastric dysrhythmias are objective, pathophysiological events related to the upper GI symptoms, especially nausea and dysmotility-like functional dyspepsia symptoms such as early satiety, fullness, and vomiting. The recording of gastric dysrhythmias is an important tool for the clinician when patients have symptoms that suggest gastric dysfunction such as unexplained nausea, bloating, postprandial fullness, and early satiety. On the other hand, these upper GI symptoms are nonspecific, and diseases or disorders of other organ systems such as esophagus, gallbladder, small bowel, colon, and non-GI diseases must be considered.