MODELING AND CHARACTERIZING DETERMINISTIC COMPONENT OF HEART RATE VARIABILITY BY CLUSTER-WEIGHTED FILTERING

2002 ◽  
Vol 12 (12) ◽  
pp. 2967-2976 ◽  
Author(s):  
ZHENYA HE ◽  
WENJIANG PEI ◽  
LUXI YANG ◽  
STEPHEN S. HULL ◽  
JOHN Y. CHEUNG
Keyword(s):  
Nonlinear Dynamics ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Nervous System ◽  
Initial Conditions ◽  
Real Data ◽  
Surrogate Data ◽  
Largest Lyapunov Exponent ◽  
Data Sets ◽  
Highly Nonlinear

The control of heart rate is primarily due to the function of the human autonomic nervous system. This process is deterministic but highly nonlinear. Due to the rapid response of the central nervous system, the actual heart rate is adjusted on a beat-to-beat basis. In this study, we propose the use of the cluster-weighted filtering (CWF) method to model the underlying deterministic mechanism of the variation of heart intervals. On a gross scale, a Gaussian network is used for function approximation to model the overall complex nonlinear dynamics of heart rate variability. At the same time, a noise reduction strategy based on Bayesian theory is used to eliminate the effects of noise on a finer scale. The algorithm iteratively models the nonlinear dynamics and reduces the noise components simultaneously. The proposed algorithm has been applied to 19 real data sets selected for analysis. The system dynamics was modeled from the experimental data sets. Based on the criterion for reconstruction used in this letter, the results suggested that the underlying deterministic dynamics could be reconstructed. A number of additional tests such as surrogate data and the largest Lyapunov exponent analyses were also carried out. Results confirmed that heart rate variability is a highly nonlinear process. It is further observed that the underlying deterministic mechanism of cardiac dynamics is highly sensitive to the initial conditions.

Demonstration of nonlinear components in heart rate variability of healthy persons

1998 ◽  
Vol 275 (5) ◽  
pp. H1577-H1584 ◽  
Author(s):  
Christian Braun ◽  
Peter Kowallik ◽  
Ansgar Freking ◽  
Dörte Hadeler ◽  
Klaus-Dietrich Kniffki ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Surrogate Data ◽  
Linear Process ◽  
Data Sets ◽  
Test Statistic ◽  
Linear Processes ◽  
Nonlinear Components ◽  
Healthy Persons ◽  
Bifurcation Chaos

We present a systematic approach for detecting nonlinear components in heart rate variability (HRV). The analysis is based on twenty-three 48-h Holter recordings in healthy persons during sinus rhythm. Although many segments of 1,024 R-R intervals are stationary, only few stationary segments of 8,192–32,768 R-R intervals can be found using a test of Isliker and Kurths ( Int. J. Bifurcation Chaos 3:1573–1579, 1993.). By comparing the correlation integrals from these segments and corresponding surrogate data sets, we reject the null hypothesis that these time series are realization of linear processes. On the basis of a test statistic exploring the differences of consecutive R-R intervals, we reject the hypothesis that the R-R intervals represent a static transformation of a linear process using optimized surrogate data. Furthermore, time irreversibility of the heartbeat data is demonstrated. We interpret these results as a strong evidence for nonlinear components in HRV. Thus R-R intervals from healthy persons contain more information than can be extracted by linear analysis in the time and frequency domain.

Efeito da manipulação vertebral sobre a modulação autonômica cardíaca

2016 ◽  
Vol 17 (5) ◽  
pp. 498
Author(s):  
Alyssa Conte Da Silva ◽  
Juliana Falcão Padilha ◽  
Jefferson Luiz Brum Marques ◽  
Cláudia Mirian De Godoy Marques
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Nervous System ◽  
Autonomic Nervous System ◽  
Spinal Manipulation ◽  
Autonomic Modulation ◽  
Autonomic Nervous ◽  
Cardiac Autonomic Modulation

Introdução: Existem poucos estudos que evidenciam a manipulação vertebral relacionada à modulação autonômica cardíaca. Objetivo: Revisar a literatura sobre os efeitos da manipulação vertebral sobre a modulação autonômica cardíaca. Métodos: Foi realizada uma busca bibliográfica nas bases de dados da saúde Medline, Pubmed e Cinahl, no período correspondido entre setembro e novembro de 2014. Foram utilizados os descritores em inglês Spinal Manipulation, Cardiac Autonomic Modulation, Autonomic Nervous System, Heart Rate Variability, além de associações entre eles. Resultados: Foram encontrados 190 artigos, sendo excluídos 39 por serem repetidos, restando 151. Destes, 124 não se encaixaram nos critérios de inclusão e após leitura crítica e análise dos materiais foram selecionados 7 artigos. Grande parte dos estudos revelou que a manipulação da coluna, independente do segmento, demonstra alterações autonômicas, tanto em nível simpático quanto parassimpático. Conclusão: Existem diferentes metodologias para avaliação da modulação autonômica cardíaca, sendo a Variabilidade da Frequência cardíaca através do eletrocardiograma a mais utilizada. A manipulação vertebral exerceu influência, na maioria dos artigos, sobre a modulação autonômica cardíaca.Palavras-chave: manipulação da coluna, sistema nervoso autônomo, variabilidade da frequência cardíaca. 

scholarly journals Nonlinearities of heart rate variability in animal models of impaired cardiac control: contribution of different time scales

2017 ◽  
Vol 123 (2) ◽  
pp. 344-351 ◽  
Author(s):  
Luiz Eduardo Virgilio Silva ◽  
Renata Maria Lataro ◽  
Jaci Airton Castania ◽  
Carlos Alberto Aguiar Silva ◽  
Helio Cesar Salgado ◽  
...  
Keyword(s):  
Nonlinear Dynamics ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Time Scales ◽  
Multiscale Entropy ◽  
Time Frequency ◽  
Cardiac Control ◽  
Long Time ◽  
Nonlinear Features ◽  
Short Time

Heart rate variability (HRV) has been extensively explored by traditional linear approaches (e.g., spectral analysis); however, several studies have pointed to the presence of nonlinear features in HRV, suggesting that linear tools might fail to account for the complexity of the HRV dynamics. Even though the prevalent notion is that HRV is nonlinear, the actual presence of nonlinear features is rarely verified. In this study, the presence of nonlinear dynamics was checked as a function of time scales in three experimental models of rats with different impairment of the cardiac control: namely, rats with heart failure (HF), spontaneously hypertensive rats (SHRs), and sinoaortic denervated (SAD) rats. Multiscale entropy (MSE) and refined MSE (RMSE) were chosen as the discriminating statistic for the surrogate test utilized to detect nonlinearity. Nonlinear dynamics is less present in HF animals at both short and long time scales compared with controls. A similar finding was found in SHR only at short time scales. SAD increased the presence of nonlinear dynamics exclusively at short time scales. Those findings suggest that a working baroreflex contributes to linearize HRV and to reduce the likelihood to observe nonlinear components of the cardiac control at short time scales. In addition, an increased sympathetic modulation seems to be a source of nonlinear dynamics at long time scales. Testing nonlinear dynamics as a function of the time scales can provide a characterization of the cardiac control complementary to more traditional markers in time, frequency, and information domains. NEW & NOTEWORTHY Although heart rate variability (HRV) dynamics is widely assumed to be nonlinear, nonlinearity tests are rarely used to check this hypothesis. By adopting multiscale entropy (MSE) and refined MSE (RMSE) as the discriminating statistic for the nonlinearity test, we show that nonlinear dynamics varies with time scale and the type of cardiac dysfunction. Moreover, as complexity metrics and nonlinearities provide complementary information, we strongly recommend using the test for nonlinearity as an additional index to characterize HRV.

scholarly journals Effects of exercise on cardiac autonomic modulation in children: literature update

2015 ◽  
Vol 28 (3) ◽  
pp. 627-636 ◽  
Author(s):  
Gustavo Henrique de Oliveira Mondoni ◽  
Luiz Carlos Marques Vanderlei ◽  
Bruno Saraiva ◽  
Franciele Marques Vanderlei
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Nervous System ◽  
Autonomic Nervous System ◽  
Parasympathetic Nervous System ◽  
Healthy Children ◽  
Autonomic Modulation ◽  
Healthy Development ◽  
Autonomic Nervous ◽  
Cardiac Autonomic Modulation

AbstractIntroduction It is known that physical exercise is beneficial and precipitates adjustments to the autonomic nervous system. However, the effect of exercise on cardiac autonomic modulation in children, despite its importance, is poorly investigated.Objective To bring together current information about the effects of exercise on heart rate variability in healthy and obese children.Methods The literature update was performed through a search for articles in the following databases; PubMed, PEDro, SciELO and Lilacs, using the descriptors “exercise” and “child” in conjunction with the descriptors “autonomic nervous system”, “sympathetic nervous system”, “parasympathetic nervous system” and also with no descriptor, but the key word of this study, “heart rate variability”, from January 2005 to December 2012.Results After removal of items that did not fit the subject of the study, a total of 9 articles were selected, 5 with healthy and 4 with obese children.Conclusion The findings suggest that exercise can act in the normalization of existing alterations in the autonomic nervous system of obese children, as well as serve as a preventative factor in healthy children, enabling healthy development of the autonomic nervous system until the child reaches adulthood.

Assessment of Autonomic Nervous System by the Analysis of Heart Rate Variability in Patients with Variant Angina

1999 ◽  
Vol 29 (6) ◽  
pp. 590 ◽  
Author(s):  
Hae Ok Jung ◽  
Ki Bae Seung ◽  
Hyo Young Lim ◽  
Dong Heon Kang ◽  
Ki Yuk Chang ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Nervous System ◽  
Autonomic Nervous System ◽  
Variant Angina ◽  
Autonomic Nervous
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