title: [Analysis of heart rate variability during parallel swinging].
abstract: OBJECTIVE
  To study the pilots' heart rate variability (HRV) characteristic before, during and after parallel swing and the possibility of evaluating vestibule-vegetative nervous reaction under linear acceleration.
  
  
  METHODS
  37 healthy male pilots participated in parallel swing test. Dynamic ECG was recorded for 15 min before, during and after swing, using model MR-4500 Holter recorder. All spectra were estimated from 15 min HRV by autoregressive (AR) modeling method, the model order (8-15) was chosen using automatic program. The ratio of lower-frequency (LF) to high-frequency (HF) power of HRV spectrum (LF/HF) was computed. The relation between change of those ratios in different swing stage and swing time was analysed.
  
  
  RESULTS
  Ratio of LF to HF during swing was markedly lower than those of before and after swing (P<0.01).
  
  
  CONCLUSIONS
  The vagal nervous activity was markedly increased during swing. There were complexity and versatility in the heart automatic nervous regulation before, during and after swing.
authors.affiliation: Institute of Space Medico-Engineering, Beijing, China.
authors.forename: W G
authors.initials: WG
authors.lastname: Li
authors.forename: X X
authors.initials: XX
authors.lastname: Yan
authors.forename: J C
authors.initials: JC
authors.lastname: Pei
mesh_terms: D000054:Acceleration; D000222:Adaptation, Physiological; D000328:Adult; D000337:Aerospace Medicine; D001341:Autonomic Nervous System / Q000502:physiology*; D004562:Electrocardiography; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D014722:Vestibule, Labyrinth / Q000502:physiology*