title: Clinical and pH study characteristics in reflux patients with and without ineffective oesophageal motility (IEM).
abstract: BACKGROUND
  The aetiology and clinical impact of ineffective oesophageal motility (IEM) remain poorly understood, but the condition is thought to worsen supine gastro-oesophageal acid reflux (GERD).
  
  
  OBJECTIVE
  In this retrospective cohort analysis of symptomatic patients with abnormal oesophageal acid exposure, we sought to determine any clinical or functional characteristics that would distinguish those with normal peristalsis from those with IEM, defined using the Chicago classification. We hypothesised that the impaired oesophageal clearance in IEM would be contributing to more severe degrees of pathological acid exposure, as well as clinical and endoscopic GERD severity.
  
  
  METHODS
  Consecutive symptomatic patients with GERD underwent clinical, endoscopic and functional evaluation that included high-resolution impedance manometry (HRIM) and ambulatory pH monitoring performed 'off' acid suppressive therapy.
  
  
  RESULTS
  Of the 114 patients with abnormal oesophageal acid exposure, 71 had normal oesophageal motility by HRIM and 43 were diagnosed with IEM (38% prevalence). Age, gender and symptom duration were similar between the two groups. Both groups had similar magnitude and frequency of symptoms, making a distinction clinically impossible. Endoscopically, the two groups had similar rates of erosive disease, hiatal hernia and Barrett's oesophagus. Ambulatory pH, proton pump inhibitor (PPI) dosage and PPI response rates were also similar. Nevertheless, patients with IEM had significantly more impairment of oesophageal clearance (mean 56.9±6.4) than those with normal motility (mean 32.4±5.0) (p<0.003).
  
  
  CONCLUSIONS
  Symptomatic patients with IEM exhibit significant impairment of oesophageal clearance but are otherwise clinically indistinguishable from those with normal oesophageal motility and have a similar prevalence of erosive disease and pathological acid exposure.
authors.affiliation: Silicon Valley Gastroenterology, Mountain View, California, USA; Division of Gastroenterology and Hepatology, Stanford University School of Medicine, Stanford, California, USA.
authors.forename: George
authors.initials: G
authors.lastname: Triadafilopoulos
authors.affiliation: Silicon Valley Gastroenterology , Mountain View, California , USA.
authors.forename: Apurva
authors.initials: A
authors.lastname: Tandon
authors.affiliation: Department of Gastroenterology , Palo Alto Medical Foundation , Mountain View, California , USA.
authors.forename: Katerina P
authors.initials: KP
authors.lastname: Shetler
authors.affiliation: Division of Gastroenterology and Hepatology , Stanford University School of Medicine , Stanford, California , USA.
authors.forename: John
authors.initials: J
authors.lastname: Clarke
keywords: GASTROESOPHAGEAL REFLUX DISEASE; MANOMETRY; OESOPHAGEAL MOTILITY DISORDER; OESOPHAGEAL PHYSIOLOGY; OESOPHAGEAL pH MONITORING