title: Unexplained chest pain: the hypersensitive, hyperreactive, and poorly compliant esophagus.
abstract: 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.
  
  
  METHODS
  Prospective study.
  
  
  METHODS
  Tertiary referral center.
  
  
  METHODS
  24 consecutive patients and 12 healthy controls.
  
  
  METHODS
  A new technique, impedance planimetry, was used to measure the sensory, motor, and biomechanical properties of the human esophagus. The impendance 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).
  
  
  CONCLUSIONS
  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.
authors.affiliation: University of Iowa College of Medicine, Iowa City, USA.
authors.forename: S S
authors.initials: SS
authors.lastname: Rao
authors.forename: H
authors.initials: H
authors.lastname: Gregersen
authors.forename: B
authors.initials: B
authors.lastname: Hayek
authors.forename: R W
authors.initials: RW
authors.lastname: Summers
authors.forename: J
authors.initials: J
authors.lastname: Christensen
mesh_terms: D000328:Adult; D000368:Aged; D001696:Biomechanical Phenomena; D002404:Catheterization; D002637:Chest Pain / Q000209:etiology*; D003187:Compliance; D004935:Esophageal Diseases / Q000503:physiopathology; D004947:Esophagus / Q000294:innervation / Q000503:physiopathology*; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008365:Manometry; D008875:Middle Aged; D011446:Prospective Studies; D012684:Sensory Thresholds / Q000502:physiology