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Intracranial pressure (ICP) burden or pressure time dose (PTD) is a valuable clinical indicator for pending intracranial hypertension, mostly based on threshold exceedance. Pulse frequency and waveform morphology (WFM) of the ICP signal contribute to PTD. The temporal resolution of the ICP signal has a great influence on PTD calculation but has not been systematically studied yet. Hence, the temporal resolution of the ICP signal on PTD calculation is investigated. We retrospectively analysed continuous 48 h ICP recordings with high temporal resolution obtained from 94 patients at the intensive care unit who underwent neurosurgery due to an intracranial haemorrhage and received an intracranial pressure probe (43 females, median age: 72 years, range: 23 to 88 years). The cumulative area under the curve above the threshold of 20 mmHg was compared for different temporal resolutions of the ICP signal (beat-to-beat, 1 s, 300 s, 1800 s, 3600 s). Events with prolonged ICP elevation were compared to those with few isolated threshold exceedances. PTD increased for lower temporal resolutions independent of WFM and frequency of threshold exceedance. PTDbeat-to-beat best reflected the impact of frequency of threshold exceedance and WFM. Events that could be distinguished in PTDbeat-to-beat became magnified more than 7-fold in PTD1s and more than 104 times in PTD1h, indicating an overestimation of PTD. PTD calculation should be standardised, and beat-by-beat PTD could serve as an easy-to-grasp indicator for the impact of frequency and WFM of ICP elevations on ICP burden.
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Lesões Encefálicas , Pressão Intracraniana , Feminino , Humanos , Idoso , Estudos Retrospectivos , Fatores de Tempo , Procedimentos NeurocirúrgicosRESUMO
OBJECTIVES: For further insight into the possibly predictive quality of the intracranial pressure (ICP) waveform morphology a definite and reliable identification of its components is a prerequisite but presents the problem of artefacts in physiological signals. METHODS: ICP and electrocardiogram (ECG) data were recorded to depict not only their numerical value but also their respective waveforms and were analysed by two algorithms, which were then compared for their artefact resistance.The algorithms in question identify the start point of every ICP wave, one (AR[SA]) by scale analysis, the other (AR[ECG]) by analysing the ICP wave linked to the ECG. RESULTS: Start-point identification accuracy in rhythmic patients showed sensitivity of 95.14% for AR[SA] and 99.99% for AR[ECG], with a positive predictive value (ppv) of 98.30% for AR[SA] and 99.76% for AR[ECG].In arrhythmic patients sensitivity was 98.05% for AR[SA] and 99.73% for AR[ECG], with a ppv of 100% for AR[SA] and 99.78% for AR[ECG]. CONCLUSIONS: AR[ECG] has proven to be more resistant to artefacts than AR[SA], even in cases such as cardiac arrhythmia. It facilitates reliable, three-dimensional visualisation of long-term changes in ICP-wave morphology and is thus suited for analysis in cases of more complex or irregular vital parameters.
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Artefatos , Pressão Intracraniana , Algoritmos , Eletrocardiografia , Humanos , Processamento de Sinais Assistido por ComputadorRESUMO
BACKGROUND: Helium in oxygen (HELIOX) can relieve airway obstruction and lower the work of breathing because it increases the threshold at which turbulent gas flow is induced. Less turbulent and more laminar flow lowers the work of breathing. According to guidelines, the fraction of Helium in HELIOX should be maximized (e.g. to 79%). Here, we investigate whether HELIOX with less than 60% of Helium is able to relieve the sensation of dyspnea in healthy volunteers. METHODS: 44 volunteers underwent resistive loading breathing different gases (medical air and HELIOX with a fraction of 25%, 50% or 75% helium in oxygen) in a double-blinded crossover design. Subjects rated their degree of dyspnea (primary outcome parameter) and the variability of noninvasively measured systolic blood pressure was assessed. RESULTS: Dyspnea was significantly reduced by HELIOX-containing mixtures with a fraction of helium of 25% or more. Similarly, blood pressure variability was reduced significantly even with helium 25% during respiratory loading with the higher load, whereas with the smaller load an effect could only be obtained with the highest helium fraction of 75%. CONCLUSION: In this clinical trial, HELIOX with less than 60% of helium in oxygen decreased the sensation of dyspnea and blood pressure variability, a surrogate parameter for airway obstruction. Therefore, higher oxygen fractions might be applied without losing the helium-related benefits for the treatment of upper airway obstruction. TRIAL REGISTRATION: Registration with clinical trials (NCT00788788) and EMA (EudraCT number: 2006-005289-37).
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Obstrução das Vias Respiratórias/terapia , Dispneia/terapia , Hélio/efeitos adversos , Oxigenoterapia/métodos , Oxigênio/efeitos adversos , Adulto , Pressão Sanguínea , Feminino , Hélio/administração & dosagem , Hélio/uso terapêutico , Humanos , Masculino , Oxigênio/administração & dosagem , Oxigênio/uso terapêutico , Estudo de Prova de ConceitoRESUMO
The analysis of symbolic dynamics applied to physiological time series retrieves dynamical properties of the underlying regulation which are robust against the symbolic transformation. In this study, three different transformations to produce a symbolic series were applied to fetal RR interval series to test whether they reflect individual changes of fetal heart rate variability in the course of pregnancy. Each transformation was applied to 215 heartbeat datasets obtained from 11 fetuses during the second and the third trimester of pregnancy (at least 10 datasets per fetus, median 17). In the symbolic series, the occurrence of symbolic sequences of length 3 was categorized according to the amount of variations in the sequence: no variation of the symbols, one variation, two variations. Linear regression with respect to gestational age showed that the individual course during pregnancy performed best using a binary transformation reflecting whether the RR interval differences are below or above a threshold. The median goodness of fit of the individual regression lines was 0.73 and also the variability among the individual slopes was low. Other transformations to symbolic dynamics performed worse but were still able to reflect the individual progress of fetal cardiovascular regulation.
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BACKGROUND: Mind-body therapies are beneficial for several diseases (e.g. chronic pain, arterial hypertension, mood disorders). Eurythmy therapy (EYT) is a mind-body therapy from Anthroposophic Medicine. In each EYT exercise a short sequence of body movements and simultaneous guided imagery is repeated several times. In this study, the simultaneous effects of two different EYT exercises on cardiac autonomic regulation as assessed by spectral analysis of heart rate variability (HRV) were investigated. METHODS: Twenty healthy subjects (age: 29.1 ± 9.3 years, 13 female) performed two different EYT exercises (EYT-A and EYT-B) for 8 min. Each EYT exercise was compared against two matched control exercises: control exercise 1 (CE1-A and CE1-B) consisted of a repetition of the body movements of the EYT exercise but without guided imagery, control exercise 2 consisted of walking on the spot (CE2-A and CE2-B). Spectral power of HRV during each exercise was quantified on the basis of Holter ECG recordings. RESULTS: During EYT-A the frequency of the peak oscillation in the very low frequency (VLF) band matched the repetition rate of the sequence of body movements (0.02 Hz). Low frequency (LF) oscillations were augmented when compared to the control exercises (EYT-A: 7.31 ± 0.84, CE1-A: 6.98 ± 0.90, CE2-A: 6.52 ± 0.87 ln ms(2), p < 0.05). They showed a peak frequency at 0.08 Hz indicating that the body postures had an impact in HRV. Performing EYT-B increased VLF oscillations when compared to the control exercises (EYT-B: 9.32 ± 0.82, CE1-B: 6.31 ± 0.75, CE2-B: 6.04 ± 0.80 ln ms(2), p < 0.05). The frequency of the peak oscillation again matched the repetition rate of the sequence of body movements (0.028 Hz). CONCLUSIONS: The repetition of the sequence of body movements of both EYT exercises clearly affected cardiac autonomic regulation in a rhythmic manner according to the stimulus of the specific body movements of each EYT exercise. These results offer a physiological basis to develop a rationale for specific clinical indications of these EYT exercises such as stress reduction or prevention of hypertension. CLINICAL TRIALS REGISTRATION NUMBER: DRKS00006760 (registered on 10/10/2014, i.e. retrospective registration); view details at http://www.drks.de/DRKS00006760.
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Sistema Nervoso Autônomo/fisiologia , Terapia por Exercício/métodos , Frequência Cardíaca , Imagens, Psicoterapia , Terapias Mente-Corpo/métodos , Movimento , Adulto , Exercício Físico , Feminino , Humanos , Hipertensão/fisiopatologia , Hipertensão/terapia , Masculino , Postura , Estudos Retrospectivos , Estresse Psicológico/fisiopatologia , Estresse Psicológico/terapia , Adulto JovemRESUMO
Physical inactivity and sedentary behaviour are important risk factors for cardiovascular disease. Knowledge about the impact of everyday movements on cardiac autonomic regulation is sparse. This study aims to provide evidence that typical everyday movements show a clear impact on heart rate regulation. 40 healthy participants performed two everyday movements: (1) calmly kneeling down ("tie one's shoes") and standing up again and (2) raising the arms to the horizontal ("expressive yawning"). Both movements elicited reproducible pattern in the sequence of heart periods. Local minima and local maxima appeared in the transient period of approx. 30 s. The regulatory response for ergometer cycling, which was used as control, did not show a pattern formation. Calmly performed everyday movements are able to elicit rich cardiac regulatory responses including specific patterns in heart rate. These newly described patterns have multiple implications for clinical and rehabilitative medicine, basic research, digital health data processing, and public health. If carried out regularly these regulatory responses may help to mitigate the burden of physical inactivity and enrich cardiovascular regulation.
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There are two basic aspects of attentional control. The ability to direct attention toward different objects is typically experienced as a fundamental indicator of attentional freedom. One can control what one attends to and directing attention is a relatively simple task. In contrast, sustaining attention on a chosen object proves to be difficult as mind-wandering seems to be inevitable. Does the problem of sustaining attention, mean that we are fundamentally unfree? We discuss this issue in light of an introspective study of directing and sustaining attention, looking specifically into the question of whether it is possible to experience the source of attention, i.e., the subject enacting freedom through attention. The study involved six persons performing different attention tasks over the course of about a month. Common experiences and contrasting reports are presented. This forms the basis for a discussion of the method of introspection and in particular of how to approach conflicting reports.
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Slow breathing at 0.1 Hz (i.e., 6 cycles per minute, cpm) leads to strong cardiovascular oscillations. However, the impact of breathing below 6 cpm is rarely addressed. We investigated the influence of OM chanting, an ancient Indian mantra, with approx. 3 respiratory cpm (0.05 Hz) on the synchronisation of heart period (RR), respiration (RESP) and systolic blood pressure (SBP). Nine healthy, trained speech practitioners chanted three sequences of five subsequent OM with 2 min pauses in between. Each single OM chanting consisted of taking a deep breath and a long "OM" during expiration and lasted approx. 20 s. ECG, respiration and blood pressure were recorded continuously, of which the RR tachogram, RESP and SBP were derived. Synchronisation between the signals was computed using the phase difference between two signals. During OM chanting synchronisation among the oscillations of RR, SBP and RESP was significantly increased compared to rest. Furthermore, OM chanting at breathing frequencies between 0.046 and 0.057 Hz resulted in 0.1 Hz oscillations in RR and SBP. In conclusion, OM chanting strongly synchronized cardiorespiratory and blood pressure oscillations. Unexpected oscillations at 0.1 Hz in SBP and RR appear at breathing frequencies of approx. 0.05 Hz. Such frequency doubling may originate from an interaction of breathing frequency with endogenous Mayer waves.
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Psychological stress may have harmful physiological effects and result in deteriorating health. Acute psychological stress acts also on cardiac autonomic regulation and may lead to nonstationarities in the interbeat interval series. We address the requirement of stationary RR interval series to calculate frequency domain parameters of heart rate variability (HRV) and use binary symbolic dynamics derived from RR interval differences to overcome this obstacle. 24 healthy subjects (12 female, 20-35 years) completed the following procedure: waiting period, Trier Social Stress Test to induce acute psychological stress, recovery period. An electrocardiogram was recorded throughout the procedure and HRV parameters were calculated for nine 5-min periods. Nonstationarities in RR interval series were present in all periods. During acute stress the average RR interval and SDNN decreased compared to rest before and after the stress test. Neither low frequency oscillations (LF), high frequency oscillations (HF) nor LF/HF could unambiguously reflect changes during acute stress in comparison to rest. Pattern categories derived from binary symbolic dynamics clearly identified acute stress and accompanying alterations of cardiac autonomic regulation. Methods based on RR interval differences like binary symbolic dynamics should be preferred to overcome issues related to nonstationarities.
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Arritmias Cardíacas/fisiopatologia , Frequência Cardíaca , Estresse Psicológico/fisiopatologia , Adulto , Feminino , Voluntários Saudáveis , Humanos , Masculino , Adulto JovemRESUMO
OBJECTIVE: In fetal diagnosis the myriad and diversity of heart rate variability (HRV) indices prevents a comparable routine evaluation of disturbances in fetal development and well-being. The work aims at the extraction of a small set of HRV key indices that could help to establish a universal, overarching tool to screen for any disturbance. APPROACH: HRV indices were organized in categories of short-term (prefix s) and long-term (prefix l) amplitude fluctuations (AMP), complexity (COMP), and patterns (PATTERN) and common representatives for each category were extracted. This procedure was done with respect to the diagnostic value in the evaluation of the maturation age throughout the second and complete third trimester of pregnancy as well as to potential differences associated with maternal life-style factors (physical exercise, smoking), nutrient intervention (docosahexaenoic acid (DHA) supplementation), and complications of pregnancy (gestational diabetes mellitus (GDM), intra-uterine growth restriction (IUGR)). MAIN RESULTS: We found a comprehensive minimal set that includes [lAMP: short term variation (STV), initially introduced in cardiotocography, sAMP: heart rate increase across one interbeat interval of phase rectified averaged signal - acceleration capacity (ACst1), lCOMP: scale 4 multi-scale entropy (MSE4), PATTERN: skewness] for the maturation age prediction, and partly overlapping [lAMP: STV, sAMP: ACst1, sCOMP: Lempel Ziv complexity (LZC)] for the discrimination of the deviations. SIGNIFICANCE: The minimal set of category-based HRV representatives allows for a screening of fetal development and well-being. These results are an important step towards a universal and comparable diagnostic tool for the early identification of developmental disturbances. Novelty & Significance Fetal development and its disturbances have been reported to be associated with a multiplicity of HRV indices. Furthermore, these HRV indices change with maturation. We propose the abstraction of HRV categories defined by short- and long-term fluctuation amplitude, complexity, and pattern indices that cover all relevant aspects of maturational age, behavioral influences and a series of pathological disturbances. The study data are provided by multiple centers. Our approach is an important step towards the goal of a standardized diagnostic tool for early identification of fetal developmental disturbances with respect to the reduction of serious complications in the later life.
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Biomarcadores/metabolismo , Desenvolvimento Fetal/fisiologia , Frequência Cardíaca Fetal/fisiologia , Área Sob a Curva , Feminino , Idade Gestacional , Humanos , Modelos Lineares , GravidezRESUMO
Heart rate variability (HRV) and cardiorespiratory coordination, i.e. the temporal interplay between oscillations of heartbeat and respiration, reflect information related to the cardiovascular and autonomic nervous system. The purpose of this study was to investigate the relationship between spectral measures of HRV and measures of cardiorespiratory coordination. In 127 subjects from a normal population a 24 h Holter ECG was recorded. Average heart rate (HR) and the following HRV parameters were calculated: very low (VLF), low (LF) and high frequency (HF) oscillations and LF/HF. Cardiorespiratory coordination was quantified using average respiratory rate (RespR), the ratio of heart rate and respiratory rate (HRR), the phase coordination ratio (PCR) and the extent of cardiorespiratory coordination (PP). Pearson's correlation coefficient r was used to quantify the relationship between each pair of the variables across all subjects. HR and HRR correlated strongest during daytime (r = 0.89). LF/HF and PP showed a negative correlation to a reasonable degree (r = -0.69). During nighttime sleep these correlations decreased whereas the correlation between HRR and RespR (r = -0.47) as well as between HRR and PCR (r = 0.73) increased substantially. In conclusion, HRR and PCR deliver considerably different information compared to HRV measures whereas PP is partially linked reciprocally to LF/HF.
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Ritmo Circadiano/fisiologia , Frequência Cardíaca/fisiologia , Respiração , Adulto , Eletrocardiografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , SonoRESUMO
BACKGROUND: Anthroposophic medicine offers a variety of treatments, among others the oil-dispersion bath, developed in the 1930s by Werner Junge. Based on the phenomenon that oil and water do not mix and on recommendations of Rudolf Steiner, Junge developed a vortex mechanism which churns water and essential oils into a fine mist. The oil-covered droplets empty into a tub, where the patient immerses for 15-30 minutes. We review the current literature on oil-dispersion baths. METHODS: The following databases were searched: Medline, Pubmed, Embase, AMED and CAMbase. The search terms were 'oil-dispersion bath' and 'oil bath', and their translations in German and French. An Internet search was also performed using Google Scholar, adding the search terms 'study' and 'case report' to the search terms above. Finally, we asked several experts for gray literature not listed in the above-mentioned databases. We included only articles which met the criterion of a clinical study or case report, and excluded theoretical contributions. RESULTS: Among several articles found in books, journals and other publications, we identified 1 prospective clinical study, 3 experimental studies (enrolling healthy individuals), 5 case reports, and 3 field-reports. In almost all cases, the studies described beneficial effects - although the methodological quality of most studies was weak. Main indications were internal/metabolic diseases and psychiatric/neurological disorders. CONCLUSION: Beyond the obvious beneficial effects of warm bathes on the subjective well-being, it remains to be clarified what the unique contribution of the distinct essential oils dispersed in the water can be. There is a lack of clinical studies exploring the efficacy of oil-dispersion baths. Such studies are recommended for the future.
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Balneologia/métodos , Banhos/métodos , Óleos Voláteis/administração & dosagem , Artrite/reabilitação , Transtorno Autístico/reabilitação , Criança , Pré-Escolar , Doença Crônica , Diabetes Mellitus/reabilitação , Feminino , Humanos , Masculino , Transtornos Mentais/reabilitação , Neurodermatite/reabilitação , Óleos Voláteis/farmacologia , Polineuropatias/reabilitaçãoRESUMO
The electrocardiogram-based cardiopulmonary coupling (CPC) technique may be used to track sleep instabilities. With progressing age, maturational changes during childhood and adolescence affect sleep. The objective was to assess developmental changes in sleep instabilities in a natural setting. ECGs during nighttime sleep on regular school days were recorded from 363 subjects aged 4 to 22 years (204 females). The estimated total sleep time (ETST) decreased from 598 to 445 min during childhood and adolescence. Stable sleep linearly decreased with progressing age (high frequency coupling (HFC): 70-48% ETST). Unstable sleep [low frequency coupling (LFC): 9-19% ETST], sleep fragmentation or disordered breathing (elevated LFC: 4-12% ETST), and wake/REM states [very low frequency coupling (VLFC): 20-32% ETST] linearly increased with age. Hence, with progressing age the sleep of children and adolescents shortens, becomes more unstable and is more often affected by fragmentation or sleep disordered breathing, especially in the age group >13 years. It remains to be clarified whether some of the changes are caused by a social jetlag, i.e., the misalignment of body clock and social time especially in adolescents.
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OBJECTIVE: Symbolic transformations of the cardiac interbeat interval series yield a coarse-grained description of the dynamical information of the underlying system and complement standard measures of heart rate variability. The most commonly utilized coarse graining procedures are strongly influenced by the presence of a few extreme values wasting precious symbols to code very unlikely values. APPROACH: Here, we used a transformation procedure that ensured the appearance of each symbol with equal probability using a short alphabet, A 4 = {0, 1, 2, 3}, and a long alphabet, A 6 = {0, 1, 2, 3, 4, 5}. The procedure was applied to the cardiac interbeat interval series of 17 healthy subjects, obtained during graded head-up tilt tests at tilt table inclinations of 0°, 15°, 30°, 45°, 60°, 75°, 90°. The dynamics of the symbolic series was assessed by the rate of symbolic pattern categories. Symbolic patterns of length three were grouped according to the variations of the symbols in each pattern: no variation (0V%), one variation (1V%), two like variations (2LV%) and two unlike variations (2UV%) of the symbols. MAIN RESULTS: As for the alphabet A 4, the linear regression analysis on tilt angle showed that 0V% increased with increasing tilt angle whereas 1V%, 2LV% and 2UV% decreased. As for the alphabet A 6, the categories 0V%, and 1V% increased with increasing tilt angle whereas 2LV% and 2UV% decreased. SIGNIFICANCE: The symbolic transformation ensuring a uniform distribution of the symbols is capable of reflecting changes in the cardiac autonomic nervous system during graded head-up tilt. This approach is more robust against outliers and data with skewed distributions compared to previously used symbolizations.
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Eletrocardiografia/métodos , Frequência Cardíaca , Processamento de Sinais Assistido por Computador , Adulto , Sistema Nervoso Autônomo/fisiologia , Feminino , Frequência Cardíaca/fisiologia , Humanos , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Postura/fisiologia , Descanso , Teste da Mesa Inclinada , Adulto JovemRESUMO
Stress is an important co-factor for the genesis and maintenance of many diseases and is known to have an effect on gene expression via epigenetic regulation. MicroRNAs (miRNAs) appear to function as one of the key factors of this regulation. This is the first study to investigate the response of 11 stress-associated miRNAs in human saliva - as a non-invasive source - in an experimental condition of acute psychological stress, and also their correlation with established psychological (subjective stress perception), physiological (heart rate and heart rate variability) and biochemical stress parameters (salivary cortisol and alpha-amylase). 24 healthy participants between 20 and 35 years of age were investigated, using the Trier Social Stress Test (TSST) to induce acute psychological stress. Stress-associated changes were significant for miR-20b, -21 and 26b, and changes in miR-16 and -134 were close to significance, recommending further research on these miRNAs in the context of stress reactions. Significant correlations with alpha-amylase suggest their integration in sympathetic stress regulation processes. Additionally, our results demonstrate the TSST as a reliable tool for studying salivary miRNAs as non-invasive indicators of epigenetic processes in acute psychological stress reactions.
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Ansiedade/genética , MicroRNAs/genética , Saliva/metabolismo , Estresse Psicológico/genética , Adulto , Ansiedade/fisiopatologia , Teste de Esforço , Feminino , Frequência Cardíaca , Humanos , Masculino , MicroRNAs/classificação , MicroRNAs/metabolismo , Estresse Psicológico/fisiopatologia , Adulto JovemRESUMO
Monitoring the fetal behavior does not only have implications for acute care but also for identifying developmental disturbances that burden the entire later life. The concept, of 'fetal programming', also known as 'developmental origins of adult disease hypothesis', e.g. applies for cardiovascular, metabolic, hyperkinetic, cognitive disorders. Since the autonomic nervous system is involved in all of those systems, cardiac autonomic control may provide relevant functional diagnostic and prognostic information. The fetal heart rate patterns (HRP) are one of the few functional signals in the prenatal period that relate to autonomic control and, therefore, is predestinated for its evaluation. The development of sensitive markers of fetal maturation and its disturbances requires the consideration of physiological fundamentals, recording technology and HRP parameters of autonomic control. Based on the ESGCO2016 special session on monitoring the fetal maturation we herein report the most recent results on: (i) functional fetal autonomic brain age score (fABAS), Recurrence Quantitative Analysis and Binary Symbolic Dynamics of complex HRP resolve specific maturation periods, (ii) magnetocardiography (MCG) based fABAS was validated for cardiotocography (CTG), (iii) 30 min recordings are sufficient for obtaining episodes of high variability, important for intrauterine growth restriction (IUGR) detection in handheld Doppler, (iv) novel parameters from PRSA to identify Intra IUGR fetuses, (v) evaluation of fetal electrocardiographic (ECG) recordings, (vi) correlation between maternal and fetal HRV is disturbed in pre-eclampsia. The reported novel developments significantly extend the possibilities for the established CTG methodology. Novel HRP indices improve the accuracy of assessment due to their more appropriate consideration of complex autonomic processes across the recording technologies (CTG, handheld Doppler, MCG, ECG). The ultimate objective is their dissemination into routine practice and studies of fetal developmental disturbances with implications for programming of adult diseases.
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Sistema Nervoso Autônomo/fisiologia , Desenvolvimento Fetal/fisiologia , Monitorização Fetal/métodos , Eletrocardiografia , Feminino , Frequência Cardíaca Fetal , Humanos , Pré-Eclâmpsia/fisiopatologia , GravidezRESUMO
It is generally assumed that fetal heart rate variability increases with gestation, reflecting prenatal development of the autonomic nervous system. We examined standard measures quantifying fetal heart rate variability, as well as a complexity measure, approximate entropy, in 66 fetal magnetocardiograms recorded from 22 healthy pregnant women between the 16th and 42nd week of gestation. In particular, regularity in the fetal RR interval time series was assessed on the basis of symbolic dynamics. The results showed that, beside an overall increase in fetal heart rate variability and complexity during pregnancy, there was also an increase in specific sets of binary patterns with low approximate entropy, i.e., a high degree of regularity. These sets were characterized by short epochs of heart rate acceleration and deceleration, and comparison with surrogate data confirmed that their random occurrence is rare. The results most likely reflect the influence of increasingly differentiated fetal behavioral states and transitions between them in association with fetal development.
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Envelhecimento/fisiologia , Algoritmos , Relógios Biológicos/fisiologia , Frequência Cardíaca Fetal/fisiologia , Modelos Cardiovasculares , Simulação por Computador , Idade Gestacional , HumanosRESUMO
Introduction. Goitre with euthyroid function or with subclinical or mild hyperthyroidism due to thyroid autonomy is common. In anthroposophic medicine various thyroid disorders are treated with Colchicum autumnale (CAU). We examined the effects of CAU in patients with goitre of both functional states. Patients and methods. In an observational study, 24 patients with goitre having suppressed thyroid stimulating hormone (TSH) levels with normal or slightly elevated free thyroxine (fT4) and free triiodothyronine (fT3) (group 1, n = 12) or normal TSH, fT3, and fT4 (group 2, n = 12) were included. After 3 months and after 6 to 12 months of CAU treatment, we investigated clinical pathology using the Hyperthyroid Symptom Scale (HSS), hormone status (TSH, fT4, and fT3), and thyroidal volume (tV). Results. After treatment with CAU, in group 1 the median HSS decreased from 4.5 (2.3-11.8) to 2 (1.3-3) (p < 0.01) and fT3 decreased from 3.85 (3.5-4.78) to 3.45 (3.3-3.78) pg/mL (p < 0.05). In group 2 tV (13.9% (18.5%-6.1%)) and TSH (p < 0.01) were reduced. Linear regression for TSH and fT3 in both groups indicated a regulative therapeutic effect of CAU. Conclusions. CAU positively changed the clinical pathology of subclinical hyperthyroidism and thyroidal volume in patients with euthyroid goitre by normalization of the regulation of thyroidal hormones.