Study type: Medical/biological study (experimental study)

Effects of 50 Hz magnetic field exposure on human heart rate variability with passive tilting. med./bio.

Published in: Physiol Meas 2006; 27 (1): 73-83

Aim of study (acc. to author)

To study possible changes in heart rate and heart rate variability due to 50 Hz magnetic fields under conditions of provocation of the sympathovagal cardiac control system, being the conditions under which environmental effects may exert their maximal influence.

Background/further details

Passive tilting was used to obtain a situation wherein sympathetic neural control was increased and physiological disturbance was minimized. Passive tilt provides a non-invasive method for quantifying the sympathovagal balance as it involves a minimal engagement of central drive and muscular activity and is compatible with quite accurate stationary conditions suitable for spectral analysis.
The tilt procedure involves passively altering a subject's position from supine to a predefined angle (in healthy subjects passive tilt causes an increase in low frequency heart rate variability and an increase in sympathetic modulation of heart rate).

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 Hz
Exposure duration: continuous for 15 min

Exposure 1

Main characteristics
Frequency 50 Hz
Type
Waveform
Polarization
  • circular
Exposure duration continuous for 15 min
Additional info Power frequency magnetic field relevant to industrial exposure.
Exposure setup
Exposure source
Setup Subjects were loosely strapped to a table which was tilted at 60°.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 28 µT unspecified unspecified - -

Reference articles

  • Sait ML et al. (1999): A study of heart rate and heart rate variability in human subjects exposed to occupational levels of 50 Hz circularly polarised magnetic fields.

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Investigated organ system:
Time of investigation:
  • before exposure
  • during exposure
  • after exposure

Main outcome of study (acc. to author)

The sympathovagal balance during tilt remained the same during both sham exposure and magnetic field exposure (there were no significant differences in the measured parameters). The data suggest that situations of sympathetic dominance do not increase the sensitivity of sympathetic neural heart rate variablity control mechanims to magnetic field exposure in the conditions used in the current experimental protocol.

Study character:

Study funded by

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