Objective: To determine whether neuromuscular dysfunction of the esophagus causes chest pain in patients in whom no disease is found on cardiac work-up, upper gastrointestinal endoscopy, esophageal manometry, and 24-hour pH studies.
Design: Prospective study.
Setting: Tertiary referral center.
Patients: 24 consecutive patients and 12 healthy controls.
Measurements: A new technique, impedance planimetry, was used to measure the sensory, motor, and biomechanical properties of the human esophagus. The impedance planimeter, which consists of a probe with four ring electrodes, three pressure sensors, and a balloon, simultaneously measures intraluminal pressure and cross-sectional areas. This allows calculation of the biomechanical variables of the esophageal wall.
Results: Stepwise balloon distentions from 5 to 50 cm H2O induced a first sensation at a mean pressure (±SD) of 15 ± 9 cm H2O in patients and 30 ± 11 cm H2O in controls (P < 0.001). Moderate discomfort and pain were reported by 20 of 24 patients (83%) at 26 ± 9 cm H2O and at 36 ± 9 cm H2O, respectively, but by none of the controls (P < 0.001). Typical chest pain was reproduced in 20 of 24 patients (83%). In patients, the reactivity of the esophagus to balloon distention was greater (P = 0.01), the pressure elastic modulus was higher (P = 0.02), and the tension-strain association showed that the esophageal wall was less distensible (P = 0.02). Distention excited tertiary contractions and secondary peristalsis at a lower threshold of pressure (P = 0.05) and with a higher motility index in patients than in controls (P = 0.04).
Conclusion: In patients with chest pain and normal cardiac and esophageal evaluations, impedance planimetry of the esophagus reproduces pain and is associated with a 50% lower sensory threshold for pain, a 50% lower threshold for reactive contractions, and reduced esophageal compliance.