The head-up tilt test with haemodynamic instability score in diagnosing chronic fatigue syndrome.
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.
Naschitz
J E
JE
Department of Internal Medicine A, Bnai Zion Medical Center, Haifa, Israel. Naschitz@tx.technion.ac.il
Rosner
I
I
Rozenbaum
M
M
Naschitz
S
S
Musafia-Priselac
R
R
Shaviv
N
N
Fields
M
M
Isseroff
H
H
Zuckerman
E
E
Yeshurun
D
D
Sabo
E
E
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*