[Hypocontraction of the esophagus in patients with Chagas' disease and with primary achalasia].

The esophageal contraction amplitude is low in patients with Chagas' disease and patients with primary achalasia but not every swallow is followed by low contraction amplitude. We evaluated the number of low contraction amplitude in 40 normal volunteers, 99 Chagas' disease patients and 14 patients with primary achalasia. Each subject performed 10 swallows of a 5 mL bolus of water and the esophageal motility was measured at 5, 10 and 15 cm above the lower esophageal sphincter by the manometric method with continuous perfusion. The amplitude of contraction was considered to be low when its value was below 30 mm Hg. There was a hypotensive contraction when the amplitude was low or when the contraction failed. The number of hypotensive contractions was higher in patients with Chagas' disease and patients with achalasia than in healthy volunteers (P < 0.05). Patients with Chagas' disease and abnormal esophageal radiological examination but without dilation had more frequent hypotensive contraction than patients with normal esophageal radiologic examination (P < 0.01). The same results were obtained for subjects with three or more hypotensive contractions (P < 0.01). The patients with Chagas' disease and dysphagia had more hypotensive contractions than patients without dysphagia (P < 0.05). We conclude that patients with Chagas' disease and patients with primary achalasia have a higher number of hypotensive contractions following wet swallows than normal volunteers, a fact that should influence the symptomatology of the patients.