Background: Topographic analysis of oesophageal motility in humans demonstrates sequential pressure regions in the peristaltic wave. This study was designed to see if cisapride preferentially affects any of the topographic regions.
Methods: Fifteen asymptomatic volunteers received placebo, 10 mg or 20 mg of cisapride orally in a double-blind, single-dose trial. Topographic plots of oesophageal peristalsis through the oesophageal body and lower sphincter were analysed before and after drug administration for each subject.
Results: Four sequential contraction segments through the oesophageal body and lower sphincter, separated by amplitude troughs, were again identified on contour plots in normal subjects. Dose-related increases from cisapride were found in the contraction volume of the first smooth-muscle segment (P<0.0001), in total contraction volume (P=0.005) and in the amplitude of the trough separating smooth-muscle segments of the oesophageal body (P=0.005). Within the distal smooth-muscle segment, significant drug effects were seen only in the cephalad half (P=0.03). Significant effects on conventional manometric parameters could not be demonstrated.
Conclusions: Cisapride enhances contraction in the proximal smooth-muscle segment of the oesophageal body and partially obliterates the pressure trough separating the adjacent smooth-muscle segment. Considering the known effects of this agent on neural function, our findings support a gradient in cholinergic influence on peristalsis through the human smooth-muscle oesophagus. Topographic analysis is a novel and sensitive way of examining the effects of pharmacological manipulations on oesophageal peristalsis.