What is the clinical evidence from this study?

Study design: Other. Population: Fetal heart rate variability (n=41). Intervention: Atropine or 6-hydroxydopamine. Primary outcome: Total spectral power and LF/HF ratio (p=<0.05).

What does this research mean for the field?

Power spectral analysis of fetal heart rate variability does not reveal substantial or consistent differences between the frequencies of sympathetic and parasympathetic activity in late-gestation fetal sheep, challenging its utility as a non-invasive estimate of autonomic balance. Novelty: ClaimNovelty.CONTRADICTORY. Consensus alignment: ConsensusAlignment.CHALLENGES_CONSENSUS.

September 7, 2013Experimental PhysiologyOpen Access

Ontogeny and control of the heart rate power spectrum in the last third of gestation in fetal sheep

Q: What are the key findings of this study?

Both atropine (P=0.05) and 6-hydroxydopamine (P<0.05) reduced overall spectral power in late-gestation fetal sheep, but neither significantly affected the LF/HF ratio.

Q: What does this research mean for the field?

Power spectral analysis of fetal heart rate variability does not reveal substantial or consistent differences between the frequencies of sympathetic and parasympathetic activity in late-gestation fetal sheep, challenging its utility as a non-invasive estimate of autonomic balance. Novelty: ClaimNovelty.CONTRADICTORY. Consensus alignment: ConsensusAlignment.CHALLENGES_CONSENSUS.

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Key result

Both atropine (P=0.05) and 6-hydroxydopamine (P<0.05) reduced overall spectral power in late-gestation fetal sheep, but neither significantly affected the LF/HF ratio.

Population

Chronically catheterized, healthy fetal sheep at 0.6, 0.7, and 0.8 gestational age for the first study. A…

Comparison

Atropine or 6-hydroxydopamine administered to… vs Different gestational ages, sleep states, and…

Design

Preclinical

Authors

MKMiriam KoomeThe Royal Melbourne Hospital LBLaura BennetUniversity of Auckland LBLindsea C. BoothThe University of Melbourne

Discussion

Member takes

Implication

Questions LF/HF validity as fetal autonomic marker; leaves open translation to human late-gestation monitoring.

Structured PICO

Population

Chronically catheterized, healthy fetal sheep at 0.6 (n=8), 0.7 (n=7), and 0.8 (n=11) gestational age for the first study. A second study included 0.8 gestational age fetuses (n=15).

Intervention

Atropine (4.8 mg bolus, then 4.8 mg/h for 30 min) or 6-hydroxydopamine (20 mg/ml at 2.5 ml/h for 3 h) administered to 0.8 gestational age fetuses.

Comparator

Different gestational ages (0.6, 0.7, 0.8), sleep states (low-voltage-high-frequency vs high-voltage-low-frequency EEG), and pre-intervention baseline.

Outcome

Developmental changes in the frequency power spectrum at very low (0-0.04 Hz), low (0.04-0.15 Hz) and high frequencies (0.15-0.4 Hz), and the ratio of low- to high-frequency power (LF/HF).surrogate

Main Result

p-value: p=<0.05

In late-gestation fetal sheep, autonomic blockade reduced overall heart rate spectral power but did not significantly alter the LF/HF ratio, suggesting this ratio may not reliably reflect sympathovagal balance before birth.

Cite This Study

Koome et al. (2013) studied Fetal heart rate variability (n=41). Atropine or 6-hydroxydopamine was evaluated on Total spectral power and LF/HF ratio (p=<0.05). Both atropine (P=0.05) and 6-hydroxydopamine (P<0.05) reduced overall spectral power in late-gestation fetal sheep, but neither significantly affected the LF/HF ratio.

synapsesocial.com/papers/6a051136fba2ba61ab55fa9f https://doi.org/10.1113/expphysiol.2013.074567

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Ontogeny and control of the heart rate power spectrum in the last third of gestation in fetal sheep

Discussion

Member takes

Implication

Structured PICO

Main Result

Cite This Study

Ontogeny and control of the heart rate power spectrum in the last third of gestation in fetal sheep

Discussion

Member takes

Implication

Structured PICO

Main Result

Cite This Study

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