Investigation of esophageal sensation and biomechanical properties in functional chest pain

Abstract

Background: There is limited and conflicting data regarding the role of esophageal hypersensitivity in the pathogenesis of functional chest pain (FCP). We examined esophageal sensori-motor properties, mechanics, and symptoms in subjects with FCP.

Methods: Esophageal balloon distension test was performed using impedance planimetry in 189 (m/f = 57/132) consecutive subjects with non-cardiac, non-reflux chest pain, and 36 (m/f = 16/20) healthy controls. The biomechanical and sensory properties of subjects with and without esophageal hypersensitivity were compared with controls. The frequency, intensity, and duration of chest pain were assessed.

Key results: One hundred and forty-three (75%) subjects had esophageal hypersensitivity and 46 (25%) had normal sensitivity. Typical chest pain was reproduced in 105/143 (74%) subjects. Subjects with hypersensitivity demonstrated larger cross-sectional area (P < 0.001), decreased esophageal wall strain (P < 0.001) and distensibility (P < 0.001), and lower thresholds for perception (P < 0.01), discomfort (P < 0.01), and pain (P < 0.01) compared to those without hypersensitivity or healthy controls. Chest pain scores (mean +/- SD) for frequency, intensity and duration were 2.5 +/- 0.3, 2.2 +/- 0.2, and 2.2 +/- 0.2, respectively, and were similar between the two patient groups.

Conclusions & inferences: Seventy-five per cent of subjects with FCP demonstrate esophageal hypersensitivity. Visceral hyperalgesia and sensori-motor dysfunction of the esophagus play a key role in the pathogenesis of chest pain.

Fig. 1

Consort diagram displaying the incidence of esophageal visceral hypersensitivity during esophageal balloon distension test.

Fig. 2

Thresholds for first sensory perception, discomfort and pain in all subject with chest pain, hypersensitive, normosensitive esophagus and healthy controls. Overall, patients had significantly lower thresholds than controls. Subjects with hypersensitive esophagus had significantly lower (p<0.01) thresholds for first perception, discomfort and pain than controls and subjects with normo-sensitive esophagus.

Fig. 3

Graded balloon distensions induced a linear increase in CSA in all three groups of subjects. CSA was significantly higher in hypersensitive group compared to those without and healthy controls.

Fig. 4

Tension-Strain relationship: stepwise increments in balloon pressure were associated with linear rise in the circumferential tension-strain relationship in the three groups. However, it was significantly shifted to the left in subjects with hypersensitive esophagus. This suggests lower esophageal distensibility in hypersensitive group.

Fig. 5

Graded balloon distensions caused an increase in esophageal wall reactivity in all three groups, but it was significantly higher in subjects with hypersensitive esophagus compared to those without and healthy controls.