Effect of bolus volume on proximal esophageal contractions of patients with Chagas' disease and patients with idiopathic achalasia.

Chagas' disease and idiopathic achalasia patients have similar impairment of distal esophageal motility. In Chagas' disease, the contractions occurring in the distal esophageal body are similar after wet or dry swallows. Our aim in this investigation was to evaluate the effect of wet swallows and dry swallows on proximal esophageal contractions of patients with Chagas' disease and with idiopathic achalasia. We studied 49 patients with Chagas' disease, 25 patients with idiopathic achalasia, and 33 normal volunteers. We recorded by the manometric method with continuous water perfusion the pharyngeal contractions 1 cm above the upper esophageal sphincter and the proximal esophageal contractions 5 cm from the pharyngeal recording point. Each subject performed in duplicate swallows of 3-mL and 6-mL boluses of water and dry swallows. We measured the time between the onset of pharyngeal contractions and the onset of proximal esophageal contractions (pharyngeal-esophageal time [PET]), and the amplitude, duration, and area under the curve (AUC) of proximal esophageal contractions. Patients with Chagas' disease and with achalasia had longer PET, lower esophageal proximal contraction amplitude, and lower AUC than controls (P≤ 0.02). In Chagas' disease, wet swallows caused shorter PET, higher amplitude, and higher AUC than dry swallows (P≤ 0.03).There was no difference between swallows of 3- or 6-mL boluses. There was no difference between patients with Chagas' disease and with idiopathic achalasia. We conclude that patients with Chagas' disease and with idiopathic achalasia have a delay in the proximal esophageal response and lower amplitude of the proximal esophageal contractions.