title: Spectral analysis of heart rate variability under mental stress.
abstract: It has been claimed that an increase in the 0.1-Hz component in power spectra of heart rate variability indicates an increased sympathetic tone. We tested 135 middle-aged unmedicated men (mean age 44 +/- 7 years) with two types of mental tasks, a reaction-time test and a mental arithmetic test, to determine whether the results were comparable with those from tilt tests. Although both tasks significantly increased the heart rate and blood pressure, to the same extent as the tilt tests, energy in the 0.1-Hz band decreased during the reaction-time test (from 899 +/- 641 to 482 +/- 430; P less than 0.01) yet was unchanged during the mental arithmetic test. We conclude that the response of the 0.1-Hz component is a task-specific phenomenon.
authors.affiliation: Department of Medicine, University of Bonn, Federal Republic of Germany.
authors.forename: W
authors.initials: W
authors.lastname: Langewitz
authors.forename: H
authors.initials: H
authors.lastname: Rüddel
mesh_terms: D001794:Blood Pressure / Q000502:physiology; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008606:Mental Processes / Q000502:physiology; D008875:Middle Aged; D011930:Reaction Time / Q000502:physiology; D012984:Software; D013315:Stress, Psychological / Q000503:physiopathology*