Shortened QT interval: a distinctive feature of the dysautonomia of chronic fatigue syndrome.
OBJECTIVE
Because autonomic nervous functioning is frequently abnormal in chronic fatigue syndrome (CFS), we examined whether the corrected QT interval (QTc) in CFS differs from QTc in other populations.


METHODS
The QTc was calculated at the end of 10 minutes of recumbence and the end of 10 minutes of head-up tilt. In a pilot study, groups of 15 subjects, CFS, and controls, matched for age and sex, were investigated. In a second phase of the study, the QTc was measured in larger groups of CFS (n = 30) and control patients (n = 96) not matched for demographic features.


RESULTS
In the pilot study, the average supine QTc in CFS was 0.371 +/- 0.02 seconds and QTc on tilt, 0.385 +/- 0.02 seconds, significantly shorter than in controls (P = .0002 and .0003, respectively). Results of phase II confirmed this data.


CONCLUSIONS
Relative short QTc intervals are features of the CFS-related dysautonomia. The significance of this finding is discussed.
Naschitz
Jochanan
J
Department of Internal Medicine A, Bnai Zion Medical Center and Rappaport Family Faculty of Medicine, Technion-Israel Institute of Technology, P.O. Box 4940, Haifa 31048, Israel. naschitz@tx.technion.ac.il
Fields
Madeline
M
Isseroff
Hillel
H
Sharif
Dauod
D
Sabo
Edmond
E
Rosner
Itzhak
I
D000328:Adult; D001342:Autonomic Nervous System Diseases / Q000175:diagnosis*; D003936:Diagnosis, Computer-Assisted / Q000379:methods*; D004562:Electrocardiography / Q000379:methods*; D015673:Fatigue Syndrome, Chronic / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008297:Male; D010865:Pilot Projects