title: Influence of computer work under time pressure on cardiac activity.
abstract: Computer users are often under stress when required to complete computer work within a required time. Work stress has repeatedly been associated with an increased risk for cardiovascular disease. The present study examined the effects of time pressure workload during computer tasks on cardiac activity in 20 healthy subjects. Heart rate, time domain and frequency domain indices of heart rate variability (HRV) and Poincaré plot parameters were compared among five computer tasks and two rest periods. Faster heart rate and decreased standard deviation of R-R interval were noted in response to computer tasks under time pressure. The Poincaré plot parameters showed significant differences between different levels of time pressure workload during computer tasks, and between computer tasks and the rest periods. In contrast, no significant differences were identified for the frequency domain indices of HRV. The results suggest that the quantitative Poincaré plot analysis used in this study was able to reveal the intrinsic nonlinear nature of the autonomically regulated cardiac rhythm. Specifically, heightened vagal tone occurred during the relaxation computer tasks without time pressure. In contrast, the stressful computer tasks with added time pressure stimulated cardiac sympathetic activity.
authors.affiliation: Institute of Rehabilitation Engineering and Technology, University of Shanghai for Science and Technology, Shanghai 200093, China. Electronic address: pshi@usst.edu.cn.
authors.forename: Ping
authors.initials: P
authors.lastname: Shi
authors.affiliation: School of Electronic, Electrical and Systems Engineering, Loughborough University, Ashby Road, Loughborough, Leicestershire LE11 3TU, United Kingdom.
authors.forename: Sijung
authors.initials: S
authors.lastname: Hu
authors.affiliation: Institute of Rehabilitation Engineering and Technology, University of Shanghai for Science and Technology, Shanghai 200093, China.
authors.forename: Hongliu
authors.initials: H
authors.lastname: Yu
mesh_terms: D000328:Adult; D003201:Computers; D004562:Electrocardiography / Q000145:classification; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D013315:Stress, Psychological / Q000503:physiopathology*; D013997:Time Factors; D055815:Young Adult
keywords: Cardiac activity; Computer–mouse work; Electrocardiogram (ECG); Heart rate variability (HRV); Poincaré plot; Spectral analysis; Stress