Functional chest pain of esophageal origin: hyperalgesia or motor dysfunction.

OBJECTIVE: Many patients with functional (noncardiac) chest pain exhibit both hypersensitivity and motor dysfunction of the esophageal wall. We aimed to determine whether the sensory or motor dysfunction plays an important role in the pathogenesis of chest pain.
METHODS: We performed graded balloon distentions of the esophagus using impedance planimetry in 16 consecutive patients with chest pain and otherwise normal cardiac and esophageal evaluations and in 13 healthy controls. In those patients who experienced chest pain with balloon distention, the test was repeated after atropine was given. Sensory and biomechanical parameters were measured.
RESULTS: Balloon distention reproduced typical chest pain in 13/16 patients (81%) and at lower (p < 0.01) sensory thresholds than controls. Pain was reproduced in all 13 patients and at lower (p < 0.05) sensory thresholds after atropine. Also, after atropine, the esophageal cross-sectional area and wall tension increased (p < 0.05), the tension/strain association shifted to the right (p < 0.05), and reactivity decreased (p < 0.002) relative to results before atropine or in healthy controls (i.e., the esophageal wall relaxed and became more deformable).
CONCLUSIONS: Even after relaxing the esophageal wall, most patients experienced chest pain and at lower sensory thresholds. Hence, hyperalgesia rather than motor dysfunction appears to be the predominant mechanism for functional chest pain of esophageal origin.