Comparison of the effects of sublingual isosorbide dinitrate and cardiomyotomy on esophageal emptying in patients with chagasic megaesophagus.

The effects of surgical cardiomyotomy and isosorbide dinitrate on esophageal emptying were compared in 18 patients with symptomatic chagasic megaesophagus. The esophageal emptying of a radiolabelled test meal was assessed three times in each patient by a scintigraphic technique, twice before and once 10-14 days after cardiomyotomy. Isosorbide dinitrate, 5 mg by the sublingual route 5 min before the meal, preceded one of the preoperative studies. Esophageal retention at the completion of the meal was significantly less (P < 0.01) after both isosorbide dinitrate and cardiomyotomy than after the preoperative study not preceded by any treatment. This difference persisted up to 10 minutes after the meal. The values measured in the isosorbide dinitrate-preceded study and after cardiomyotomy were not different (P > 0.10) even though esophageal retention at the completion of the meal was slightly less after cardiomyotomy than after isosorbide dinitrate. These results show that isosorbide dinitrate and cardiomyotomy cause similar enhancement of esophageal emptying in chagasic megaesophagus.