GASTRIC MYOELECTRICAL ACTIVITY IN PATIENTS WITH GASTRIC OUTLET OBSTRUCTION AND IDIOPATHIC GASTROPARESIS

Objective: The cause of gastroparesis may be uncertain in some patient s. Mechanical obstruction of the stomach or duodenum should be exclude d in patients with idiopathic gastroparesis, The objective of this stu dy was to compare gastric myoelectrical activity in patients with idio pathic gastroparesis with that of patients with gastroparesis due to m echanical obstruction of the stomach or duodenum, Methods: Electrogast rography techniques were used to record gastric myoelectrical activity in 20 patients with idiopathic gastroparesis and in nine patients wit h gastroparesis secondary to gastric outlet obstruction. Four of these nine patients initially were thought to have idiopathic gastroparesis , Electrogastrograms (EGGs) were recorded from 29 healthy subjects who served as controls. EGGs were recorded for 20-30 min 2 h after a stan dard 200-Kcal meal and were analyzed visually and by computer. Results : Patients with gastroparesis due to outlet obstruction had high-ampli tude and excessively regular 3-cycles-per-minute (cpm) EGG patterns, w hereas patients with idiopathic gastroparesis had primarily 1- to 2-cp m patterns and little 3-cpm EGG activity. The percentage of total EGG power in the 3-cpm range was approximately 50% in patients with gastri c outlet obstruction compared with 20% in patients with idiopathic gas troparesis (p < 0.001). The percentage of EGG power in the normal 3-cp m range was greater in the obstructed patients (50%) than in the healt hy controls (35%;p < 0.052). Conclusions: Gastric myoelectrical patter ns recorded in the EGG distinguish mechanical and idiopathic causes of gastroparesis and may be useful in evaluating patients with nausea, v omiting, and gastroparesis of unknown cause. (Am J Gastroenterol 1998; 93:1803-1809. (C) 1998 by Am. Cell. of Gastroenterology)