Electrogastrography: physiological basis and clinical application in diabetic gastropathy.

Electrogastrography is the recording and measurement of gastric myoelectrical activity from electrodes placed on the surface of the epigastrium. Normal electrogastrograms (EGGs) reflect 3 cycles per min (cpm) gastric myoelectrical activity produced by specialized pacemaker cells, the interstitial cells of Cajal, located in the muscular wall of the gastric corpus and antrum. Gastric dysrhythmias (tachygastrias and bradygastrias) are disturbances of the normal gastric pacesetter potentials and are associated with symptoms of nausea, epigastric fullness, and bloating and with hyperglycemia and delayed gastric emptying. In diabetic gastropathy, the normal 3-cpm electrical rhythm is replaced with bradygastrias, tachygastrias, and mixed or nonspecific dysrhythmias. Diagnosis of gastric dysrhythmias identifies an objective neuromuscular abnormality in diabetic patients with upper gastrointestinal (GI) symptoms. Correction of gastric dysrhythmias decreases upper GI symptoms and may improve gastric emptying all of which may enhance glucose control. The EGG diagnosis of gastric dysrhythmias provides new insights into gastric neuromuscular abnormalities and guides therapies to improve upper GI symptoms in patients with diabetes mellitus.