title: The head-up tilt test with haemodynamic instability score in diagnosing chronic fatigue syndrome.
abstract: BACKGROUND
  Studying patients with chronic fatigue syndrome (CFS), we have developed a method that uses a head-up tilt test (HUTT) to estimate BP and HR instability during tilt, expressed as a 'haemodynamic instability score' (HIS).
  
  
  OBJECTIVE
  To assess HIS sensitivity and specificity in the diagnosis of CFS.
  
  
  METHODS
  Prospective controlled study.
  
  
  METHODS
  Patients with CFS (n=40), non-CFS chronic fatigue (n=73), fibromyalgia (n=41), neurally mediated syncope (n=58), generalized anxiety disorder (n=28), familial Mediterranean fever (n=50), arterial hypertension (n=28), and healthy subjects (n=59) were evaluated with a standardized head-up tilt test (HUTT). The HIS was calculated from blood pressure (BP) and heart rate (HR) changes during the HUTT.
  
  
  RESULTS
  The tilt was prematurely terminated in 22% of CFS patients when postural symptoms occurred and the HIS could not be calculated. In the remainder, the median(IQR) HIS values were: CFS +2.14(4.67), non-CFS fatigue -3.98(5.35), fibromyalgia -2.81(2.62), syncope -3.7(4.36), generalized anxiety disorder -0.21(6.05), healthy controls -2.66(3.14), FMF -5.09(6.41), hypertensives -5.35(2.74) (p<0.0001 vs. CFS in all groups, except for anxiety disorder, p=NS). The sensitivity for CFS at HIS >-0.98 cut-off was 90.3% and the overall specificity was 84.5%.
  
  
  CONCLUSIONS
  There is a particular dysautonomia in CFS that differs from dysautonomia in other disorders, characterized by HIS >-0.98. The HIS can reinforce the clinician's diagnosis by providing objective criteria for the assessment of CFS, which until now, could only be subjectively inferred.
authors.affiliation: Department of Internal Medicine A, Bnai Zion Medical Center, Haifa, Israel. Naschitz@tx.technion.ac.il
authors.forename: J E
authors.initials: JE
authors.lastname: Naschitz
authors.forename: I
authors.initials: I
authors.lastname: Rosner
authors.forename: M
authors.initials: M
authors.lastname: Rozenbaum
authors.forename: S
authors.initials: S
authors.lastname: Naschitz
authors.forename: R
authors.initials: R
authors.lastname: Musafia-Priselac
authors.forename: N
authors.initials: N
authors.lastname: Shaviv
authors.forename: M
authors.initials: M
authors.lastname: Fields
authors.forename: H
authors.initials: H
authors.lastname: Isseroff
authors.forename: E
authors.initials: E
authors.lastname: Zuckerman
authors.forename: D
authors.initials: D
authors.lastname: Yeshurun
authors.forename: E
authors.initials: E
authors.lastname: Sabo
mesh_terms: D000328:Adult; D000368:Aged; D001794:Blood Pressure / Q000502:physiology*; D015673:Fatigue Syndrome, Chronic / Q000175:diagnosis* / Q000503:physiopathology; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D018667:Tilt-Table Test / Q000379:methods*