DISTAL ESOPHAGEAL MOTILITY CHARACTERISTICS IN RELATION TO AMPLITUDE OF CONTRACTION IN HEALTHY-PERSONS

Objectives: We wanted to apply a new 'vertical' approach in the analys is of oesophageal contraction data by describing variables of oesophag eal function in relation to the amplitude of contraction. Methods. Twe nty-four-hour oesophageal manometry was performed in 20 healthy volunt eers (11 women and 9 men; mean age, 47.5 years). Computer analysis was performed in pressure windows at 10, 15, 20, 30, 40, 50, 60, 70, and 80 mm Hg. Within each window two variables were extracted: the distrib ution (%) of peristaltic contractions and median duration (sec) of con tractions. Results: The percentage of peristaltic contractions increas ed with increasing amplitude of contractions during the upright positi on (15-20 mm Hg window: mean (+/-SD) 68.2% (+/-13.3%), versus 70-80 mm Hg window: 85.0% (+/-13.0%) (P < 0.001)) and meal periods (66.9% (+/- 13.8%) versus 92.2% (+/-11.2%) (P < 0.001)) but not in the supine posi tion (75.9% (+/-14.6%) versus 73.5% (+/-16.1%) (P = 0.64)). Contractio n duration diminished with increasing contraction amplitude (upright, 15-20 mm Hg window: 3.2 sec (+/-1.5 sec) versus 70-80 mm Hg window: 1. 5 sec (+/-1.0 sec) (P < 0.0001); meal: 3.8 sec (+/-1.7 sec) versus 1.9 sec (+/-1.1 sec) (P < 0.01); supine: 4.1 sec (+/-3.0 sec) versus 2.2 (+/-1.5 sec) (P = 0.03)). The percentage of peristaltic contractions w as lower during the supine periods than during meals and upright perio ds at high amplitudes (70-80 mm Hg window; P < 0.05). The number of co ntractions decreased linearly on a logarithmic scale with pressure win dow amplitude. Conclusions: Pressure wave amplitude and organization w ere closely related. Accurate base-line determination and delineation are critical for the interpretation of oesophageal manometric recordin gs.