Reversal of asynchrony between circular and longitudinal muscle contraction in nutcracker esophagus by atropine

Background & Aims: Patients with high-amplitude esophageal contractions (nutcracker esophagus [NCE]) show asynchrony of circular muscle (CM) and longitudinal muscle (LM) contraction during peristalsis. The goal of our study was to determine if this asynchrony is related to an increase in the cholinergic receptor activity. Methods: High-frequency intraluminal ultrasound images and pressures of the esophagus were recorded simultaneously in 10 normal subjects and 10 patients with NCE. Recordings were obtained at 2 cm above the lower esophageat sphincter under 2 study conditions in normal subjects (before and after 80 mu gm/kg of edrophonium), and under 3 study conditions in the NCE patients (control, 5 mu gm and 10 mu gm/kg of atropine). Results: In normal subjects, edrophonium induced an increase in the CM and LM contraction amplitude, an increase in the contraction duration, and asynchrony of LM and CM contraction during peristalsis. On the other hand, increased contraction amplitude, duration, and asynchrony of LM and CM contraction observed at the baseline in the NCE patients were reversed by atropine in a dose-dependent fashion. Conclusions: These data prove that the esophageal motor abnormalities in patients with nutcracker esophagus, including asynchrony of CM and LM contraction, are related to a hypercholinergic state.