Effect of phasic contractions and tone of the proximal stomach on triggering of transient lower esophageal sphincter relaxation

Abstract

We hypothesized that transient lower esophageal sphincter relaxation (TLESR) is triggered by a discrete motor event, i.e., a phasic contraction or a tonic change of the proximal stomach. The combined esophageal manometry-gastric barostat tracings obtained from 11 healthy subjects during 2-hr continuous isobaric gastric distension were reviewed. Volume waves, i.e., phasic contractions, were analyzed in the 1 and 5 min before onset of each TLESR and in corresponding control periods. Intrabag volume, i.e., proximal gastric tone, was also measured in the 5-min periods. The number of volume waves was similar in the 1- and 5-min pre-TLESR and control periods (0 [0-1], median [IQ range], vs 0 [0-1] and 4 [0.8-5] vs 3 [2-4], respectively], and so were their amplitude, duration, and frequency distribution. Five-minute intrabag volume was also similar (529 +/- 77 [mean +/- SE] vs 532 +/- 74 ml). Our observations suggest that TLESR is not triggered by a preceding phasic contraction or by a different tone of the proximal stomach.