Normal esophageal body function: A study using ambulatory esophageal manometry

Objective: The objective of this study was to establish normative ambulatory manometric data for contractions and contraction propagation in three levels of the esophagus. Methods: Twenty-five healthy volunteers underwent simultaneous ambulatory 24 h manometry. Concomitant 24 h pH studies were performed to exclude the presence of increased esophageal acid exposure. Pressures were recorded over a complete circadian cycle while patients continued with their normal lifestyles including eating and sleeping. Data were analyzed with a software program that was previously modified and validated and that enables quantitation of contractions in terms of efficacy. Results: The frequency of contractions was lowest during sleep, was increased when awake, and was highest during meals. Contraction amplitude increased during meals, providing a greater propulsive force for bolus transport. Similarly, the prevalence of peristaltic waves varied according to different physiologic states, i.e., while eating, upright, awake, and sleeping. An increased amplitude and prevalence of peristalsis resulted in an increase in manometric efficacy during meals. Conclusions: This study provides normative data for ambulatory manometry for comparison when studying patients with disease