title: Segmental changes in smooth muscle contraction as a predictive factor of the response to high-dose proton pump inhibitor treatment in patients with functional chest pain.
abstract: OBJECTIVE
  High-dose proton pump inhibitor (PPI) treatment leads to relatively little symptomatic improvement in patients with functional chest pain (FCP). This study was to evaluate the use of smooth muscle segmental changes in esophageal contraction as measured by topographical plots of high resolution manometry (HRM) as predictive factors of the response to high-dose PPI treatment in FCP patients.
  
  
  METHODS
  Thirty patients diagnosed with FCP were treated with rabeprazole 20 mg twice daily for 2 weeks and classified as positive and negative responders based on symptom intensity score. HRM topographical plots were analyzed for segment lengths, maximal wave amplitudes, and pressure volumes of the proximal and distal smooth muscle segments.
  
  
  RESULTS
  A positive response was observed in 23.3% of the patients. While the pressure volume of the proximal segment was significantly higher in the positive responders than the negative responders (900.4 ± 91.5 mm Hg/cm per s vs. 780.5 ± 133.3 mm Hg/cm per s, P = 0.017), the pressure volume of the distal segment was significantly lower in the positive responders (1914.0 ± 159.8 mm Hg/cm per s vs. 2140.5 ± 276.2 mm Hg/cm per s, P = 0.014). A prominent shifting in pressure volume to the distal segment was observed in the negative responders compared with the positive responders (segmental ratio of pressure volume (SRPV): 2.9 ± 0.5 vs. 2.1 ± 0.1, P < 0.001), and 2.39 was found to be the SRPV that best differentiated positive and negative responders.
  
  
  CONCLUSIONS
  A low SRPV was associated with a positive response to high-dose PPI treatment in patients with FCP.
authors.affiliation: Department of Internal Medicine, Institute of Gastroenterology, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Hyuk
authors.initials: H
authors.lastname: Lee
authors.forename: Jun Chul
authors.initials: JC
authors.lastname: Park
authors.forename: Sung Kwan
authors.initials: SK
authors.lastname: Shin
authors.forename: Sang Kil
authors.initials: SK
authors.lastname: Lee
authors.forename: Yong Chan
authors.initials: YC
authors.lastname: Lee
mesh_terms: D053799:2-Pyridinylmethylsulfinylbenzimidazoles / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use; D000328:Adult; D002637:Chest Pain / Q000188:drug therapy* / Q000209:etiology / Q000503:physiopathology; D004334:Drug Administration Schedule; D050782:Esophageal pH Monitoring; D004947:Esophagus / Q000187:drug effects* / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D008365:Manometry / Q000379:methods; D008875:Middle Aged; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects* / Q000503:physiopathology; D011379:Prognosis; D054328:Proton Pump Inhibitors / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D064750:Rabeprazole; D012720:Severity of Illness Index; D016896:Treatment Outcome
chemical_list: D053799:2-Pyridinylmethylsulfinylbenzimidazoles; D054328:Proton Pump Inhibitors; D064750:Rabeprazole