Pressure-geometry relationship in the antroduodenal region in humans

Understanding of the control mechanisms underlying gastric motor function i s still limited. The aim of the present study was to evaluate antral pressu re-geometry relationships during gastric emptying slowed by intraduodenal n utrient infusion and enhanced by erythromycin. In seven healthy subjects, a ntral contractile activity was assessed by combined dynamic magnetic resona nce imaging and antroduodenal high-resolution manometry. After intragastric administration of a 20% glucose solution (750 ml), gastric motility and em ptying were recorded during intraduodenal nutrient infusion alone and, subs equently, combined with intravenous erythromycin. Before erythromycin, cont raction waves were antegrade (propagation speed: 2.7 +/- 1.7 mm/s; lumen oc clusion: 47 +/- 14%). Eighty-two percent (51/62) of contraction waves were detected manometrically. Fifty-four percent of contractile events (254/473) were associated with a detectable pressure event. Pressure and the degree of lumen occlusion were only weakly correlated (r(2) = 0.02; P = 0.026). Af ter erythromycin, episodes of strong antroduodenal contractions were observ ed. In conclusion, antral contractions alone do not reliably predict gastri c emptying. Erythromycin induces strong antroduodenal contractions not nece ssarily associated with fast emptying. Finally, manometry reliably detects similar to 80% of contraction waves, but conclusions from manometry regardi ng actual contractile activity must be made with care.