Multichannel Electrogastrography (EGG) in Symptomatic Patients: A Single Center Study

OBJECTIVES To determine the value of multichannel versus conventional single-channel electrogastrography (EGG) and of an additional postprandial hour recording in symptomatic patients. METHODS Eighteen normal subjects and 47 patients with upper GI symptoms underwent multichannel EGG with four cutaneous recording electrodes placed on the antral axis. Fasting EGG was recorded for 1 h, followed by meal ingestion, followed by two 1-h postprandial EGG recordings. Variables assessed: (1) dominant frequency (DF) and its power; (2) percent time in normal (2–4) cpm frequency; (3) average percent of slow wave coupling (% SWC). RESULTS Normal values for single-channel EGG were: (1) DF from 2.5–3.3, 2.7–3.5, and 2.6–3.5 cpm in the fasting, first, and second postprandial hours; (2) percentage of time in 2–4 cpm: >50%, >65%, and >65% in the fasting, first, and second postprandial hours. Normal values for percent SWC using multichannel EGG were >50%, >55%, >55% in the fasting, first, and second postprandial hours. In the symptomatic patients, an abnormal 2-h single-channel EGG was obtained in 16 of 47 (34%) patients. Adding an additional 1 h of postprandial recording identified another 4 abnormal patients (20/47 = 43%). With multichannel EGG, abnormal results were obtained in 24 of 47 patients (51%) with the 2-h study. An additional 1 h of postprandial recording identified another 4 patients as abnormal (28/47 = 60%). CONCLUSIONS Multichannel EGG recording improved the detection of abnormal gastric myoelectric activity in symptomatic patients. This study also demonstrates prolonging the postprandial recording to 2 h increases the diagnostic yield for both single-channel and multichannel EGG.