[Diaphragmatic contraction in the lower esophageal sphincter pressure in Chagas disease patients].

Contraction of the crural diaphragm increases the lower esophageal sphincter (LES) pressure, which is important for preventing gastroesophageal reflux. Our objective in this study was to compare the influence of diaphragmatic contraction on LES pressure of Chagas' disease patients with dysphagia, and control volunteers. We studied 17 patients with positive serologic reactions for Chagas' disease, dysphagia and slow transit of barium sulphate through the esophagus. Two also had esophageal dilatation. Twelve healthy volunteers were the control group. LES pressure was measured by the station pull-through (SPT) method with a round manometric catheter with four side holes opened at the same level, 10 cm from the end of the catheter, infused with water at a flow of 0.5 ml/minute. The catheter was introduced through the nose until the four side holes reached the stomach. After five minutes of stabilization it was withdrawn 1 cm every 15 seconds while the patient or volunteer breathed normally. We measured the difference in LES pressure recorded at inspiration and expiration, which is the contribution of the diaphragmatic contraction to LES pressure. There was no difference in this value between controls (18.5 +/- 9.6 mmHg, mean +/- SD) and patients (17.9 +/- 7.6 mmHg, P > 0.05). The value increased with LES pressure, suggesting that the diaphragm may participate in LES pressure asymmetry. We conclude that the diaphragmatic contribution to LES pressure in Chagas' disease patients is the same as that of normal subjects.