INCREASING PAIN SENSATION TO REPEATED ESOPHAGEAL BALLOON DISTENSION IN PATIENTS WITH CHEST PAIN OF UNDETERMINED ETIOLOGY

Previous studies have demonstrated lowered sensory thresholds to esoph ageal balloon distension in patients with chest pain of undetermined e tiology. Whether this finding is specific to patients with chest pain or is simply related to an underlying esophageal motility disorder is unclear. In the present study, distension-induced pain-sensation score s and the effect of repeated balloon distension were compared in patie nts with chest pain, dysphagia secondary to esophageal dysmotility, an d healthy controls. All subjects underwent standard esophageal manomet ry followed by mid-esophageal balloon distension. Volumes 2.5, 5, 7.5, and 10 ml (each volume repeated three times) were applied in random o rder in a single-blind fashion, and the pain-sensation score was recor ded after each distension. Pain-sensation scores varied directly with balloon volume. Mean pain scores were significantly higher (P < 0.001) in the chest pain group than in either the controls or dysphagia grou p. There was no significant difference between controls and the dyspha gia group, and the motor response to distension was no different betwe en groups. In the controls and dysphagia groups, pain-sensation score was not significantly different between the first, second, or third di stension at a given volume. However, in the chest pain group, pain-sen sation scores increased significantly with the second (P 0.004) or thi rd (P = 0.002) distension using the same balloon volume. These studies suggest that abnormal esophageal nociception in patients with chest: pain of undetermined etiology is not simply related to underlying esop hageal motor dysfunction. In addition, chest pain patients display a c onditioning phenomenon, further supporting the presence of a visceral sensory abnormality.