Katleen Bogaerts (1), M.A, Morgane Hubin (1), M.A, Ilse Van Diest (1), Ph.D., Stephan Devriese (1), Ph.D.,
Boudewijn Van Houdenhove (2), M.D., Ph.D., Peter Van Wambeke (2), M.D., Ph.D., & Omer Van den Bergh (1), Ph.D.

(1) Department of Psychology, University of Leuven, Belgium.
(2) University Hospital Gasthuisberg, University of Leuven, Belgium

Hyperventilation has been suggested as a concomitant of Chronic Fatigue Syndrome (CFS) that may contribute to the symptom pattern, and as a possible maintaining factor of the disease.

Because patients accepting the disease and trying to live with it seem to have a better prognosis than patients chronically fighting it, we investigated breathing behavior during different coping response sets towards the disease in patients with CFS (N=30, CDC criteria).

Patients imagined a relaxation script (baseline), a script describing a coping response of active defence and nonacceptance, and a script depicting response of acceptance of the disease and its (future) consequences.

Finally, patients were instructed to mentally prepare for a demanding bicycle ergometer test, as part of the standard diagnostical protocol.

During each imagery trial and during anticipation of physical exercise, end-tidal PCO2 (Microcap® Handheld Capnograph, Oridion) was measured, as well as heart rate and breathing behavior (time and volume parameters, using respiratory inductive plethysmography, LifeShirt, VivoMetrics).

After each trial, patients filled out a symptom checklist.

Results showed low resting values of PetCO2 overall, while only imagery of hostile resistance triggered a decrease and deficient recovery of PetCO2.

Also more hyperventilation complaints and complaints of other origin were reported during hostile resistance imagery compared to acceptance and relaxation.

Hostile resistance seems to trigger both physiological and symptom perception processes, contributing to the clinical picture of CFS.