Effects of neuromuscular blockade on fetal heart rate variability:
a power spectrum analysis..
O., Sibony, Fouillot J. P., Luton D., Oury J. F., Blot P.
D[acute]epartement de p[acute]erinatologie, H[circumflex]opital
Robert Debr[acute]e, Paris, France, Laboratoire de physiologie des
adaptations, H[circumflex]opital Cochin, Paris, France.
APStracts 2:0072A, 1995.
Spectral analysis of fetal heart rate variability allows quantative
determination of the main components affecting this variability. The
physiological significance of these components is unclear, however
movements appear to contribute to variability. We studied 6 fetuses
in which immobility required for in utero magnetic resonance or
invasive fetal procedures was achieved by fetal intravascular
injection of curare, between 32 and 36 amenorrhea weeks. For each
fetus, we compared spectral density parameters of heart rate
variability. Following curare administration, mean spectrum power was
halved. We did not observe a larger significant decrease in any
frequency band (very low, low and high frequency bands). The other
parameters of spectral analysis of variability were unaltered. Fetal
movements accounted for a significant proportion of human fetal heart
rate variability but did not constitute a unique frequency component.
Received 20 December 1994; accepted in final form 21 February
1995.
APS Manuscript Number A1296-4.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 7 March 1995.