title: Copeptin levels in patients with vasovagal syncope.
abstract: OBJECTIVE
  Vasovagal syncope (VVS) is linked to more than one pathophysiologic mechanisms. Copeptin, an emerging cardiovascular marker, is a surrogate for arginine-vasopressin, which increases following VVS. We aimed to assess the dynamic pattern of copeptin levels in typical VVS, categorized by the degree of vasoconstriction during orthostasis, and healthy controls.
  
  
  METHODS
  The following groups were studied: Group A (n=21), with adequate limb vasoconstriction during the first min. of tilt, assessed by limb plethysmography (at least 30% flow reduction); Group B (n=15), showing impaired vasoconstriction during orthostasis (<10% reduction); Group C (n=18), history of VVS and negative tilt test result; Group D (n=18), healthy controls. Copeptin plasma levels were assessed before and 5min following tilt test positivity or termination.
  
  
  RESULTS
  Baseline copeptin values were similar in all groups (8.3±6.4 in Group A, 5.7±2.3pmol/l in B, 6.0±1.9 in C, and 6.9±2.6 in D, p: 0.41). Significant increases in copeptin during tilt were observed in all Groups of VVS patients (A, B, C), including those with negative tilt (Group C: from 6.0±1.9 to 27.7±12.6pmol/l, p: 0.001), but not in controls. Following tilt termination, a greater increase was observed in copeptin values in Group B vs all other Groups A, C, and D (111.6±63.5 vs 29.5±51.3, 27.7±12.6, and 8.3±2.9, respectively).
  
  
  CONCLUSIONS
  Copeptin increases following tilt not only in VVS with a positive response, but also in typical history patients with a negative test. Increased copeptin levels following orthostasis may be useful for diagnosing VVS.
authors.affiliation: 2nd Department of Cardiology, Attikon University Hospital, Athens, Greece. Electronic address: pflevari@yahoo.com.
authors.forename: Panayota
authors.initials: P
authors.lastname: Flevari
authors.affiliation: 2nd Department of Cardiology, Attikon University Hospital, Athens, Greece.
authors.forename: Dionyssios
authors.initials: D
authors.lastname: Leftheriotis
authors.affiliation: Department of Biochemistry, Attikon University Hospital, Athens, Greece.
authors.forename: Christos
authors.initials: C
authors.lastname: Kroupis
authors.affiliation: Department of Biochemistry, Attikon University Hospital, Athens, Greece.
authors.forename: George
authors.initials: G
authors.lastname: Antonakos
authors.affiliation: 2nd Department of Cardiology, Attikon University Hospital, Athens, Greece.
authors.forename: John
authors.initials: J
authors.lastname: Lekakis
authors.affiliation: Department of Biochemistry, Attikon University Hospital, Athens, Greece.
authors.forename: Kleanthi
authors.initials: K
authors.lastname: Dima
mesh_terms: D015415:Biomarkers / Q000097:blood; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006020:Glycopeptides / Q000097:blood*; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010991:Plethysmography; D011498:Protein Precursors; D012189:Retrospective Studies; D019462:Syncope, Vasovagal / Q000097:blood* / Q000175:diagnosis / Q000503:physiopathology; D018667:Tilt-Table Test; D014661:Vasoconstriction / Q000502:physiology*
chemical_list: D015415:Biomarkers; D006020:Glycopeptides; D011498:Protein Precursors; C048197:copeptins
keywords: Arginine-vasopressin; Copeptin; Syncope; Vasoconstriction