Response of the lower esophageal sphincter to pentagastrin on patients with megaesophagus secondary to Chagas' disease.

In 12 patients with moderate chagasic megaesophagus the lower esophageal sphincter pressure was studied under basal conditions and after i. v. infusion of pentagastrin by open tips infused rapid pull through manometry. Pentagastrin was infused in graded doses of 0.5, 1.0, 2.0 and 4.0 micrograms/kg/h. Results were compared with those of 12 healthy controls. Mean basal pressure in the megaesophagus group was significantly higher (p less than 0.05) than in the control group (36.2 +/- 2.5 and 27.4 +/- 1.8 cmH2O, respectively). Following pentagastrin infusion all the values of the lower esophageal sphincter pressure were significantly higher in the chagasic group (p less than 0.05). The plateau was achieved with 0.5 micrograms/kg/h in the control group and with 1.0 micrograms/kg/h in the chagasic group (p less than 0.05). Furthermore, the patients with megaesophagus needed a higher dose of pentagastrin to achieve the maximal contraction.