Alterations in irregular and fractal heart rate behavior in growth restricted fetuses

Yum, Myung‐Kul; Park, Eun‐Young; Kim, Chang-Ryul; Hwang, Jin Ho

doi:10.1016/s0301-2115(00)00314-6

Cited by 25 publications

(19 citation statements)

References 17 publications

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“…There is no available data on non-linear HR analysis of MCT injected rats to compare with our results. However, similar changes in linear and non-linear HR indices have been observed in human pre and post natal conditions related to heart failure intrauterine growth restriction [25,34,38]. On the other hand, a maintenance of linear and non-linear HR indices, or an increase, namely on week 4, was observed in the non-MCT group, except of LF/HF, denoting a long-term increase of the overall activity of linear and complex HR control systems, with a parasympathetic dominance.…”

Section: Discussionsupporting

confidence: 56%

Analysis of heart rate variability in a rat model of induced pulmonary hypertension

Gonçalves¹,

Henriques‐Coelho²,

Bernardes³

et al. 2010

Medical Engineering & Physics

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a b s t r a c tMonocrotaline (MCT) is commonly used to experimentally induce pulmonary hypertension (PH), which might lead to chronic heart failure. In this study, linear and non-linear heart rate (HR) dynamics were weekly assessed in MCT-treated and non-treated Wistar rats.The HR of 10 adult Wistar rats injected with MCT (MCT group) and of 10 similar rats injected with vehicle (non-MCT group), anesthetized with Ketamine, was weekly recorded during 4 weeks. The first four segments of 1-min length of each HR recording were analysed using linear, time and frequency domains, and approximate (ApEn) and sample (SampEn) entropy indices, considering recently proposed values for the threshold parameter of ApEn and SampEn. Statistical analysis was performed using 95% confidence intervals and statistical tests.Along the study period, an overall weekly maintenance of HR indices, or a decrease, namely in weeks 1-2, was manifest, in the MCT group, except for LF and LF/HF, in week 1, denoting a short-term increase in sympathetic activity without any other changes. On the other hand, a maintenance of HR indices, or an increase, namely on week 4, was observed in the non-MCT group, except for LF/HF, denoting a long-term increase of the overall activity of HR control systems, with a parasympathetic like dominance.Studies on long-term HR dynamics should be performed in very carefully controlled experimental settings, as significant weekly changes may occur, both among anesthetized MCT-treated and non-treated rats.

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Section: Discussionsupporting

confidence: 56%

Analysis of heart rate variability in a rat model of induced pulmonary hypertension

Gonçalves¹,

Henriques‐Coelho²,

Bernardes³

et al. 2010

Medical Engineering & Physics

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“…The fluctuations were characterized by a self-similarity parameter ( ␣ ) representing the long-range fractal correlation properties of the signal. The exponent ␣ is 0.5 for white noise with uncorrelated randomness, 1 for 1/f noise and long-range fractal correlations, and 1.5 for Brown motion [12,13] . We evaluated the fractal scaling exponent ␣ 1 from 4 to 40 beats, and ␣ 2 from 40 to 1,000 beats [14] .…”

Section: Extraction and Analysis Of Hr Variability Parametersmentioning

confidence: 99%

“…a less adaptable system with either a totally uncorrelated randomness or a highly predictable behavior [21] . Such degradation of long-range correlation properties has been found to be associated with various pathologic states from elderly to fetus [13,21] .…”

Section: Meaning Of the Studymentioning

confidence: 99%

Uncorrelated Randomness of the Heart Rate Is Associated with Sepsis in Sick Premature Infants

Beuchée¹,

Carrault

Bansard

et al. 2009

Neonatology

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Background: Late-onset sepsis in the premature infant is frequently revealed by severe, unusual and recurrent bradycardias. In view of the high morbidity and mortality associated with infection, reliable markers are needed. Objectives: It was the aim of this study to determine if heart rate (HR) behavior may help the diagnosis of infection in premature infants with such cardiac decelerations. Methods: Electrocardiogram recordings were collected in 51 premature infants with a postmenstrual age <33 weeks with frequent bradycardias. Newborns in the sepsis group (C-reactive protein increase and positive blood culture) were compared with a no-sepsis group (C-reactive protein <5 mg/l before and 24 h after recording and negative blood cultures) for their HR characteristics, i.e. RR series distribution (mean, median, skewness, kurtosis, sample asymmetry), magnitude of variability in time and frequency domain, fractal exponents (α₁, α₂) and complexity measurements (approximate and sample entropy). Results are presented as the median (25%, 75%). Results: Gestational, chronological and postmenstrual age and gender were similar in the sepsis (n = 10) and no-sepsis group (n = 38). Three infants had an increase in C-reactive protein but negative cultures. Low entropy measurements [approximate entropy 0.4 (0.3, 0.5) vs. 0.8 (0.6, 1); p < 0.001] and long-range fractal exponent [α₂ 0.78 (0.71, 0.83) vs. 0.92 (0.8, 1.1); p < 0.05] were significantly associated with sepsis. No other HR characteristic was associated with sepsis. The decrease in 0.1 units of approximate entropy was associated with an over 2-fold increase in the odds of sepsis. Conclusion: Late-onset sepsis is associated with uncorrelated randomness of the HR. This abnormal HR behavior may help to monitor premature infants presenting with frequent and severe bradycardias.

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“…Using Higuchi's [27] method, FHR sequences were found to have two characteristic scaling regions, one for a shorter time scale ranging from 500 ms to 5 s and the other for a longer time scale of 1 30 s [28] . Yum et al [31] also found this break point near 80 beats by DFA. These results suggest that the FHR behavior having a time scale longer than about 30 s is different from that having a shorter time scale.…”

Section: Discussionmentioning

confidence: 73%

“…Yum et al [31] also reported these values to be 1.379 8 0.007 and 0.857 8 0.016 (mean 8 SE), respectively, in normal fetuses after 31 gestational weeks. In addition, our study also confirmed that although the values of the short-term ( ␣ 1 ) scaling exponent calculated from FHR traces of SGA fetuses were not significantly different from those of healthy normal fetuses, the values of the long-term ( ␣ 2 ) scaling exponent from SGA fetuses were significantly higher than those of healthy normal fetuses.…”

Section: Discussionmentioning

confidence: 86%

Detrended Fluctuation Analysis of Heart Rate Variability in Normal and Growth-Restricted Fetuses

Kikuchi

Unno²,

Kozuma³

et al. 2007

Gynecol Obstet Invest

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Background: Detrended fluctuation analysis (DFA) has recently been validated as an excellent method by which to analyze heart rate variability and distinguish healthy subjects from patients with various types of the cardiac nervous system dysfunction. Methods: One hundred and nineteen fetal heart rate (FHR) recordings obtained from healthy normal fetuses and 68 recordings obtained from small-for-gestational-age (SGA) fetuses were analyzed by DFA to examine gestational and pathologic changes of the scaling exponent, α. Results: In normal fetuses, a significant increase was observed in both the short-term (≤30 s) α₁ and long-term (>30 s) α₂ scaling exponents according to gestational age. The α₁ values of SGA fetuses were not significantly different from those of healthy normal fetuses; however, the α₂ values of the former group (0.955 ± 0.152) were significantly higher than those of normal subjects (0.887 ± 0.128; p = 0.001). Conclusion: The α₂ exponent appears to be a sensitive probe for detecting subtle, and possibly important, changes that occur in fetuses with intrauterine growth restriction, and may be helpful in the early and noninvasive detection of placental insufficiency or incipient intrauterine growth restriction. The use of DFA techniques offers great promise for understanding FHR behavior.

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Alterations in irregular and fractal heart rate behavior in growth restricted fetuses

Cited by 25 publications

References 17 publications

Analysis of heart rate variability in a rat model of induced pulmonary hypertension

Analysis of heart rate variability in a rat model of induced pulmonary hypertension

Uncorrelated Randomness of the Heart Rate Is Associated with Sepsis in Sick Premature Infants

Detrended Fluctuation Analysis of Heart Rate Variability in Normal and Growth-Restricted Fetuses

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