Development and Significance of a Fetal Electrocardiogram Recorded by Signal-Averaged High-Amplification Electrocardiography

Hayashi, R.; Nakai, Kenta; Fukushima, Akimune; Itoh, Masatoshi; Sugiyama, Toru

doi:10.1536/ihj.50.161

Cited by 12 publications

(15 citation statements)

References 26 publications

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“…Development of the sympathetic nerves begins around the 20th gestational week, later than does that of the parasympathetic nerves, and is most rapid during the 26th to 30th gestational weeks, which coincide with the period of rapid increase in the LF power [1]. Another study [19] reported that LF/HF ratio was enhanced at 32 weeks or later, which was consistent with previous report [20] of a conversion point at 32 weeks of gestation. These neural control mechanisms will nearly reach the neonatal level in the 37th gestational week.…”

Section: Gradual Increase In Sympathetic Activity With Foetal Cardiovsupporting

confidence: 87%

Tone Entropy Analysis of Foetal Heart Rate Variability

Khandoker

Karmakar

Kimura

et al. 2015

Entropy

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Development of the foetal autonomic nervous system can be indirectly understood by looking at the changes in beat to beat variability in foetal heart rates. This study presents Tone-Entropy (T-E) analysis of foetal heart rate variability (HRV) at multiple lags (1-8) to understand the influence of gestational ages (early and late) on the development of the foetal autonomic nervous system (ANS). The analysis was based on foetal electrocardiograms (FECGs) of 46 healthy foetuses of 20-32 weeks (early group) and 22 foetuses of 35-41 weeks (late group). Tone represents sympatho-vagal balance and entropy the total autonomic activities. Results show that tone increases and entropy decreases at all lags for the late foetus group. On the other hand, tone decreases and entropy increases at lags 1-4 in the early foetus group. Increasing tone in late foetuses might represent significant maturation of sympathetic nervous systems because foetuses approaching to delivery period need increased sympathetic activity. T-E could be quantitative clinical index to determine the early foetuses from late ones on the basis of maturation of autonomic nervous system.

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Section: Gradual Increase In Sympathetic Activity With Foetal Cardiovsupporting

confidence: 87%

Tone Entropy Analysis of Foetal Heart Rate Variability

Khandoker

Karmakar

Kimura

et al. 2015

Entropy

View full text Add to dashboard Cite

show abstract

“…100 mV) with a low signal-to-noise ratio, and so the T wave of the fECG can only be detected consistently from about 15 weeks. Figure 6 collects data from the literature on the period of the human foetal heartbeat, obtained from ultrasonography [23,24], and RR intervals and QT intervals, obtained from fECG [25,26] or foetal magnetocardiographic recordings [27]. The period and RR intervals (represented by black squares in figure 6) decrease from approximately 640 ms (at four weeks) to a minimum of 350 ms (at eight weeks) and then drift upward to around 400 ms for the remaining period of gestation.…”

Section: Rsfsroyalsocietypublishingorg Interface Focus 3: 20120065mentioning

confidence: 99%

Antenatal architecture and activity of the human heart

et al. 2013

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One contribution of 25 to a Theme Issue 'The virtual physiological human: integrative approaches to computational biomedicine'. We construct the components for a family of computational models of the electrophysiology of the human foetal heart from 60 days gestational age (DGA) to full term. This requires both cell excitation models that reconstruct the myocyte action potentials, and datasets of cardiac geometry and architecture. Fast lowangle shot and diffusion tensor magnetic resonance imaging (DT-MRI) of foetal hearts provides cardiac geometry with voxel resolution of approximately 100 mm. DT-MRI measures the relative diffusion of protons and provides a measure of the average intravoxel myocyte orientation, and the orientation of any higher order orthotropic organization of the tissue. Such orthotropic organization in the adult mammalian heart has been identified with myocardial sheets and cleavage planes between them. During gestation, the architecture of the human ventricular wall changes from being irregular and isotropic at 100 DGA to an anisotropic and orthotropic architecture by 140 DGA, when it has the smooth, approximately 1208 transmural change in myocyte orientation that is characteristic of the adult mammalian ventricle. The DT obtained from DT-MRI provides the conductivity tensor that determines the spread of potential within computational models of cardiac tissue electrophysiology. The foetal electrocardiogram (fECG) can be recorded from approximately 60 DGA, and RR, PR and QT intervals between the P, R, Q and T waves of the fECG can be extracted by averaging from approximately 90 DGA. The RR intervals provide a measure of the pacemaker rate, the QT intervals an index of ventricular action potential duration, and its rate-dependence, and so these intervals constrain and inform models of cell electrophysiology. The parameters of models of adult human sinostrial node and ventricular cells that are based on adult cell electrophysiology and tissue molecular mapping have been modified to construct preliminary models of foetal cell electrophysiology, which reproduce these intervals from fECG recordings. The PR and QR intervals provide an index of conduction times, and hence propagation velocities (approx. 1-10 cm s 21, increasing during gestation) and so inform models of tissue electrophysiology. Although the developing foetal heart is small and the cells are weakly coupled, it can support potentially lethal re-entrant arrhythmia.

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“…In addition, analysis of sympathetic nerve activity and depolarization and repolarization abnormalities is possible from the same recording, and the DREAM-ECG system can be used to record fetal ECG. 24) In the future, we would like to see DREAM-ECG used for maternal and perinatal screening of ECG abnormalities such as prolongation QT syndrome of the fetus and myocardial damage in pregnant women.…”

Section: Discussionmentioning

confidence: 99%

Detection of Peripartum Myocardial Burden by Vector-Projected 187 Channel Electrocardiography and Serum NT-proBNP

et al. 2013

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SummaryThere is no reliable method of screening for pregnant women at high risk of developing severe myocardial disorders. In this study, we used vector-projected 187 channel electrocardiography (DREAM-ECG) and serum biochemical markers to evaluate peripartum myocardial burden in pregnant women. Forty-one pregnant women were examined at 36-37 weeks gestation (GW36), 7 days postpartum (PPD7), and 1 month postpartum (PPM1). Ten non-pregnant control women were assessed at a single time point. Heart rate, sympathetic index, and repolarization index (RTc dispersion) were quantified using the DREAM-ECG system, and serum levels of NT-proBNP, cardiac troponin T, estrogen, and progesterone were determined. Heart rate and the sympathetic index decreased from GW36 to PPM1 (P = 0.0031). The repolarization index decreased over time and was greater than in non-pregnant controls (31 ± 13 ms). Estrogen and progesterone at PPD7 and PPM1 were significantly lower than those at GW36 (P < 0.0001, P < 0.001). NT-proBNP at PPD7 was greater than at GW36 (median 29 pg/mL at GW36, 86 pg/mL at PPD7), and decreased at PPM1 in comparison to PPD7 (median 18.5 pg/mL). Troponin T was in the normal range during the whole period (< 0.003 ng/mL). In conclusion, these results indicate that the peripartum myocardial burden in pregnant women does not return to normal nonpregnant levels by PPM1. We propose that both repolarization indexes such as RTc dispersion by DREAM-ECG and serum biochemical markers may identify pregnant women at high risk of developing severe myocardial damage in the peripartum period. (Int Heart J 2013; 54: 140-145)

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Development and Significance of a Fetal Electrocardiogram Recorded by Signal-Averaged High-Amplification Electrocardiography

Cited by 12 publications

References 26 publications

Tone Entropy Analysis of Foetal Heart Rate Variability

Tone Entropy Analysis of Foetal Heart Rate Variability

Antenatal architecture and activity of the human heart

Detection of Peripartum Myocardial Burden by Vector-Projected 187 Channel Electrocardiography and Serum NT-proBNP

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