PMID- 31802494
OWN - NLM
STAT- MEDLINE
DCOM- 20210210
LR  - 20230201
IS  - 1469-7793 (Electronic)
IS  - 0022-3751 (Linking)
VI  - 598
IP  - 2
DP  - 2020 Jan
TI  - First evidence that intrinsic fetal heart rate variability exists and is affected 
      by hypoxic pregnancy.
PG  - 249-263
LID - 10.1113/JP278773 [doi]
AB  - KEY POINTS: We introduce a technique to test whether intrinsic fetal heart rate 
      variability (iFHRV) exists and we show the utility of the technique by testing 
      the hypothesis that iFHRV is affected by chronic fetal hypoxia, one of the most 
      common adverse outcomes of human pregnancy complicated by fetal growth 
      restriction. Using an established late gestation ovine model of fetal development 
      under chronic hypoxic conditions, we identify iFHRV in isolated fetal hearts and 
      show that it is markedly affected by hypoxic pregnancy. Therefore, the isolated 
      fetal heart has intrinsic variability and carries a memory of adverse 
      intrauterine conditions experienced during the last third of pregnancy. ABSTRACT: 
      Fetal heart rate variability (FHRV) emerges from influences of the autonomic 
      nervous system, fetal body and breathing movements, and from baroreflex and 
      circadian processes. We tested whether intrinsic heart rate variability (iHRV), 
      devoid of any external influences, exists in the fetal period and whether it is 
      affected by chronic fetal hypoxia. Chronically catheterized ewes carrying male 
      singleton fetuses were exposed to normoxia (n = 6) or hypoxia (10% inspired O(2) 
      , n = 9) for the last third of gestation (105-138 days of gestation (dG); term 
       approximately 145 dG) in isobaric chambers. At 138 dG, isolated hearts were studied using a 
      Langendorff preparation. We calculated basal intrinsic FHRV (iFHRV) indices 
      reflecting iFHRV's variability, predictability, temporal symmetry, fractality and 
      chaotic behaviour, from the systolic peaks within 15 min segments in each heart. 
      Significance was assumed at P < 0.05. Hearts of fetuses isolated from hypoxic 
      pregnancy showed approximately 4-fold increases in the Grid transformation as 
      well as the AND similarity index (sgridAND) and a 4-fold reduction in the 
      scale-dependent Lyapunov exponent slope. We also detected a 2-fold reduction in 
      the Recurrence quantification analysis, percentage of laminarity (pL) and 
      recurrences, maximum and average diagonal line (dlmax, dlmean) and the Multiscale 
      time irreversibility asymmetry index. The iHRV measures dlmax, dlmean, pL and 
      sgridAND correlated with left ventricular end-diastolic pressure across both 
      groups (average R(2)  = 0.38 +/- 0.03). This is the first evidence that iHRV 
      originates in fetal life and that chronic fetal hypoxia significantly alters it. 
      Isolated fetal hearts from hypoxic pregnancy exhibit a time scale-dependent 
      higher complexity in iFHRV.
CI  - (c) 2019 The Authors. The Journal of Physiology (c) 2019 The Physiological Society.
FAU - Frasch, Martin G
AU  - Frasch MG
AUID- ORCID: 0000-0003-3159-6321
AD  - Department of Obstetrics and Gynecology, University of Washington, Seattle, WA, 
      USA.
FAU - Herry, Christophe L
AU  - Herry CL
AD  - Dynamical Analysis Laboratory, Clinical Epidemiology Program, Ottawa Hospital 
      Research Institute, Ottawa, ON, Canada.
FAU - Niu, Youguo
AU  - Niu Y
AD  - Department of Physiology Development & Neuroscience, University of Cambridge, 
      Cambridge, UK.
FAU - Giussani, Dino A
AU  - Giussani DA
AUID- ORCID: 0000-0002-1308-1204
AD  - Department of Physiology Development & Neuroscience, University of Cambridge, 
      Cambridge, UK.
LA  - eng
GR  - FS/12/74/29778/BHF_/British Heart Foundation/United Kingdom
GR  - RG/06/006/22028/BHF_/British Heart Foundation/United Kingdom
GR  - RG/17/8/32924/BHF_/British Heart Foundation/United Kingdom
GR  - CIHR/Canada
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20200109
PL  - England
TA  - J Physiol
JT  - The Journal of physiology
JID - 0266262
SB  - IM
MH  - Animals
MH  - Female
MH  - Fetal Heart/physiopathology
MH  - Fetal Hypoxia/*physiopathology
MH  - *Heart Rate, Fetal
MH  - Male
MH  - Pregnancy
MH  - Pregnancy Complications/*physiopathology
MH  - Sheep
OTO - NOTNLM
OT  - FHRV
OT  - HRV
OT  - IUGR
OT  - Langendorff
OT  - fetus
OT  - hypoxia
OT  - sheep
EDAT- 2019/12/06 06:00
MHDA- 2021/02/11 06:00
CRDT- 2019/12/06 06:00
PHST- 2019/08/08 00:00 [received]
PHST- 2019/11/11 00:00 [accepted]
PHST- 2019/12/06 06:00 [pubmed]
PHST- 2021/02/11 06:00 [medline]
PHST- 2019/12/06 06:00 [entrez]
AID - 10.1113/JP278773 [doi]
PST - ppublish
SO  - J Physiol. 2020 Jan;598(2):249-263. doi: 10.1113/JP278773. Epub 2020 Jan 9.