title: Functional aspects of distal oesophageal spasm: the role of onset velocity and contraction amplitude on bolus transit.
abstract: BACKGROUND
  Distal oesophageal spasm is a rare and under-investigated motility abnormality. Recent studies indicate effective bolus transit in varying percentages of distal oesophageal spasm patients.
  
  
  OBJECTIVE
  Explore functional aspects including contraction onset velocity and contraction amplitude cut-off values for simultaneous contractions to predict complete bolus transit.
  
  
  METHODS
  We re-examined data from 107 impedance-manometry recordings with a diagnosis of distal oesophageal spasm. Receiver operating characteristic analysis was conducted, regarding effects of onset velocity on bolus transit taking into account distal oesophageal amplitude and correcting for intra-individual repeated measures.
  
  
  RESULTS
  Mean area under the receiver operating characteristic curve for saline and viscous swallows were 0.84±0.05 and 0.84±0.04, respectively. Velocity criteria of >30 cm/s when distal oesophageal amplitude>100 mmHg and 8 cm/s when distal oesophageal amplitude<100 mmHg for saline and 32cm/s when distal oesophageal amplitude>100 mmHg and >7 cm/s when distal oesophageal amplitude<100 mmHg for viscous had a sensitivity of 75% and specificity of 80% to identify complete bolus transit. Using these criteria, final diagnosis changed in 44.9% of patients. Abnormal bolus transit was observed in 50.9% of newly diagnosed distal oesophageal spasm patients versus 7.5% of patients classified as normal. Distal oesophageal spasm patients with distal oesophageal amplitude>100 mmHg suffered twice as often from chest pain than those with distal oesophageal amplitude<100 mmHg.
  
  
  CONCLUSIONS
  The proposed velocity cut-offs for diagnosing distal oesophageal spasm improve the ability to identify patients with spasm and abnormal bolus transit.
authors.affiliation: Digestive Disease Center, Division of Gastroenterology and Hepatology, Medical University of South Carolina, USA. Daniel.Pohl@usz.ch
authors.forename: Daniel
authors.initials: D
authors.lastname: Pohl
authors.forename: Jody
authors.initials: J
authors.lastname: Ciolino
authors.forename: Jason
authors.initials: J
authors.lastname: Roberts
authors.forename: Edoardo
authors.initials: E
authors.lastname: Savarino
authors.forename: Janice
authors.initials: J
authors.lastname: Freeman
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Nietert
authors.forename: Radu
authors.initials: R
authors.lastname: Tutuian
authors.forename: Donald
authors.initials: D
authors.lastname: Castell
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D019540:Area Under Curve; D003679:Deglutition / Q000502:physiology*; D015155:Esophageal Spasm, Diffuse / Q000175:diagnosis* / Q000503:physiopathology*; D049630:Esophageal Sphincter, Lower / Q000503:physiopathology; D004947:Esophagus / Q000503:physiopathology; D005260:Female; D005772:Gastrointestinal Transit; D006801:Humans; D008297:Male; D008365:Manometry; D008875:Middle Aged; D009119:Muscle Contraction; D010992:Plethysmography, Impedance; D012372:ROC Curve; D012189:Retrospective Studies; D055815:Young Adult