title: Do Jackhammer contractions lead to achalasia? A longitudinal study.
abstract: BACKGROUND
  Jackhammer esophagus (JE) is a rare esophageal motility disorder defined in the Chicago Classification of Esophageal Motility by presence of excessively high distal contractile integral (DCI) on high-resolution manometry (HRM), with unknown natural manometric course. We examined the development of achalasia over time in patients with JE.
  
  
  METHODS
  Through a retrospective longitudinal design, patients with Jackhammer contractions who had more than one HRM between 2005 and 2015 were identified. Any change in manometric finding was assessed for the presence of achalasia. Demographic and manometric risk factors for this progression were then sought in univariate analysis.
  
  
  RESULTS
  Of 3363 HRM studies, 229 subjects had multiple manometries, accounting for 528 studies. Twelve subjects met our inclusion criteria for JE on any of the multiple tests, represented by 27 studies for a total of 347 patient-months of manometric follow-up. Subjects with JE whose manometry included impedance demonstrated consistent esophageal bolus clearance. Of 12 subjects with Jackhammer contractions, three subjects progressed to type III achalasia, over a mean of 24 months (range: 19-31 months). At the time of diagnosis with JE, impaired esophago-gastric junction relaxation was seen in all three subjects and was the only risk factor that could predict progression to achalasia (P<.01).
  
  
  CONCLUSIONS
  In this unique study of the natural course of JE, we have shown that JE can progress to achalasia. Manometric findings at the time of JE diagnosis might predict this progression.
authors.affiliation: Department of Internal Medicine, Cedars-Sinai Medical Center, Los Angeles, California.
authors.forename: L
authors.initials: L
authors.lastname: Huang
authors.affiliation: GI Motility Program, Cedars-Sinai Medical Center, Los Angeles, California.
authors.forename: M
authors.initials: M
authors.lastname: Pimentel
authors.affiliation: GI Motility Program, Cedars-Sinai Medical Center, Los Angeles, California.
authors.forename: A
authors.initials: A
authors.lastname: Rezaie
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004931:Esophageal Achalasia / Q000175:diagnosis* / Q000503:physiopathology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008365:Manometry / Q000379:methods / Q000639:trends*; D008875:Middle Aged; D009119:Muscle Contraction / Q000502:physiology*; D012189:Retrospective Studies; D055815:Young Adult
keywords: Jackhammer esophagus; achalasia; esophagus; hypercontractile esophagus; manometry; motility