Relationship between ultrasonically detected phasic antral contractions and antral pressure

The relationships between gastric wall motion and intraluminal pressure are believed to be major determinants of flows within and from the stomach. Ga stric antral wall motion and intraluminal pressures were monitored in five healthy subjects by concurrent antropyloroduodenal manometry and transabdom inal ultrasound for 60 min after subjects drank 500 ml of clear soup. We fo und that 99% of antral contractions detected by ultrasound were propagated aborally, and 68% of contractions became lumen occlusive at the site of the ultrasound marker. Of the 203 contractions detected by ultrasound, 53% wer e associated with pressure events in the manometric reference channel; 86% of contractions had corresponding pressure events detectable somewhere in t he antrum. Contractions that occluded the lumen were more likely to be asso ciated with a pressure event in the manometric reference channel (P < 0.01) and to be of greater amplitude (P < 0.01) than non-lumen-occlusive contrac tions. We conclude that heterogeneous pressure event patterns in the antrum occur despite a stereotyped pattern of contraction propagation seen on ult rasound. Lumen occlusion is more likely to be associated with higher peak a ntral pressure events.