Acid perfusion and edrophonium provocation tests in patients with chest pain of undetermined etiology.

During the last five years, 672 patients were referred to our esophageal investigation unit; 110 patients (16.3%) of these presented with chest pain of undetermined etiology (CPUE) alone. Since the nature of this pain is intermittent and rarely present during the diagnostic study, acid perfusion and intravenous edrophonium tests were added as provocative tests after baseline esophageal manometry. Following completion of the motility studies, 24-hr pH study was performed to detect gastroesophageal reflux (GER). Twenty-nine patients (26.4%) had positive acid perfusion (APT) test whereas 26 patients (23.6%) had positive edrophonium test (ET). In the group of patients with positive acid perfusion test, 12/29 (41.3%) had GER, 8/29 (27.5%) had both motility disorder and GER, 2/29 (6.8%) had motility disorder, and 7/29 (24.1%) had normal esophageal motility and 24-hr pH studies. In the other group, 13/26 (50%) had motility disorder and 13/26 (50%) had both motility disorder and GER. There were no significant differences between the two tests as far as reproducibility of symptoms was concerned. We conclude that ATP and ET showed the esophageal origin of CPUE in half of our patients and therefore in a substantial percentage of patients the esophageal origin of chest pain will remain very difficult to prove.