title: Topographic analysis of esophageal double-peaked waves.
abstract: OBJECTIVE
  Esophageal double-peaked waves occur with increased frequency in patients with functional esophageal symptoms. This study was undertaken to further understand the mechanisms responsible for their production.
  
  
  METHODS
  Topographic methods that consider temporal and spatial relationships of pressure data were used to examine 74 double-peaked waves detected in 18 subjects referred for manometric evaluation of unexplained symptoms. The studies were performed with a computerized data acquisition and analysis system designed for topographic plotting.
  
  
  RESULTS
  The second peak appeared to represent muscle contraction that merged with an unusually strong pressure site in the third topographic segment and covered 6.3 +/- 1.6 cm (33.5% +/- 8.5% esophageal length) proximal to this site. In 50 swallows (67.6%), the peak itself progressed in a retrograde direction at 13.2 +/- 10.8 cm/s, suggesting cephalad extension of a strong distal motor event. Analysis of wave onsets and movement of the peristaltic trailing edge detected retrograde propagation in up to 33.8% of waves, antegrade propagation in 2.7%, and simultaneous contraction in the remainder.
  
  
  CONCLUSIONS
  In symptomatic patients, the second peak in a double-peaked wave is typically a short, simultaneous, or retrograde pressure event in the region of and merging with the third topographic segment in the distal esophageal body. Topographic methods help explain the common association of these waveforms with other features of exaggerated contraction in the distal esophagus and suggest their relationship to inadequate inhibitory nerve function.
authors.affiliation: Division of Gastroenterology, Washington University School of Medicine, St. Louis, Missouri 63110, USA. rclouse@im.wustl.edu
authors.forename: R E
authors.initials: RE
authors.lastname: Clouse
authors.forename: A
authors.initials: A
authors.lastname: Staiano
authors.forename: A
authors.initials: A
authors.lastname: Alrakawi
mesh_terms: D000328:Adult; D003679:Deglutition; D003936:Diagnosis, Computer-Assisted; D004935:Esophageal Diseases / Q000503:physiopathology*; D004947:Esophagus / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008365:Manometry; D008875:Middle Aged; D009119:Muscle Contraction; D009130:Muscle, Smooth / Q000503:physiopathology; D010528:Peristalsis; D011312:Pressure; D013997:Time Factors