THE SIGNIFICANCE OF ELECTROGASTROGRAPHICALLY DETERMINED AMPLITUDES - IS THERE A CORRELATION TO SONOGRAPHICALLY MEASURED ANTRAL MECHANICAL CONTRACTIONS

Cutaneous electrogastrography (EGG) allows the measurement of gastric electrical activity. An association of EGG with gastrointestinal motil ity disorders has been shown. Abnormalities of electrical rate or rhyt hm are accepted as the most important parameters in EGG. However, the reliability of the magnitude of electrical amplitude in the assessment of motility is discussed controversially Therefore in a prospective s tudy we investigated the relation between amplitude and antral contrac tions by means of ultrasonography. 8 healthy volunteers (4 men, 4 wome n, 24-31 years)ingested 400 mi carbonated mineral water after an overn ight fast at two separate study days. Over a period of 10 min preprand ial and 10 min postprandial small and intense antral contractions were measured employing sagittal antral planimetry. Simultaneous amplitude s were determined during contractions and at 1 min intervals (average amplitude) by cutaneous electrogastrography. Data were analyzed by Wil coxon's rank sum test and Spearman rank correlation test. The coeffici ent of variation of the postprandial/preprandial amplitude ratio was n early two times greater between subjects than between recordings in th e same subject, which reflects a moderate intraindividual reproducibil ity. We found a significant increase in the average amplitude postpran dially (p < 0.05). Although postprandial contractions (n = 243) predom inated preprandial contractions (n = 127) significantly (p = 0.02), no significant correlation between the number of contractions and the av erage amplitude existed (R = 0.1; p = 0.7). Moreover the average ampli tude did not differ from amplitudes during intense and small contracti ons significantly (p = 0.7; p = 0.1). The magnitude of the amplitude m easured by EGG does not correlate with the mechanical gastral activity significantly. Therefore, the amplitude in EGG is probably an unsuita be parameter in assessing gastric motility.