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Pichot V, Roche F, Celle S, Barthélémy JC, Chouchou F. HRVanalysis: A Free Software for Analyzing Cardiac Autonomic Activity. Front Physiol 2016; 7:557. [PMID: 27920726 PMCID: PMC5118625 DOI: 10.3389/fphys.2016.00557] [Citation(s) in RCA: 89] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Accepted: 11/04/2016] [Indexed: 11/13/2022] Open
Abstract
Since the pioneering studies of the 1960s, heart rate variability (HRV) has become an increasingly used non-invasive tool for examining cardiac autonomic functions and dysfunctions in various populations and conditions. Many calculation methods have been developed to address these issues, each with their strengths and weaknesses. Although, its interpretation may remain difficult, this technique provides, from a non-invasive approach, reliable physiological information that was previously inaccessible, in many fields including death and health prediction, training and overtraining, cardiac and respiratory rehabilitation, sleep-disordered breathing, large cohort follow-ups, children's autonomic status, anesthesia, or neurophysiological studies. In this context, we developed HRVanalysis, a software to analyse HRV, used and improved for over 20 years and, thus, designed to meet laboratory requirements. The main strength of HRVanalysis is its wide application scope. In addition to standard analysis over short and long periods of RR intervals, the software allows time-frequency analysis using wavelet transform as well as analysis of autonomic nervous system status on surrounding scored events and on preselected labeled areas. Moreover, the interface is designed for easy study of large cohorts, including batch mode signal processing to avoid running repetitive operations. Results are displayed as figures or saved in TXT files directly employable in statistical softwares. Recordings can arise from RR or EKG files of different types such as cardiofrequencemeters, holters EKG, polygraphs, and data acquisition systems. HRVanalysis can be downloaded freely from the Web page at: https://anslabtools.univ-st-etienne.frHRVanalysis is meticulously maintained and developed for in-house laboratory use. In this article, after a brief description of the context, we present an overall view of HRV analysis and we describe the methodological approach of the different techniques provided by the software.
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Affiliation(s)
- Vincent Pichot
- EA SNA-EPIS 4607, Department of Clinical and Exercise Physiology, University of Lyon, Jean Monnet University Saint-Etienne, France
| | - Frédéric Roche
- EA SNA-EPIS 4607, Department of Clinical and Exercise Physiology, University of Lyon, Jean Monnet University Saint-Etienne, France
| | - Sébastien Celle
- EA SNA-EPIS 4607, Department of Clinical and Exercise Physiology, University of Lyon, Jean Monnet University Saint-Etienne, France
| | - Jean-Claude Barthélémy
- EA SNA-EPIS 4607, Department of Clinical and Exercise Physiology, University of Lyon, Jean Monnet University Saint-Etienne, France
| | - Florian Chouchou
- NeuroPain Unit, Lyon Neuroscience Research Centre, Institut National de la Santé et de la Recherche Médicale U 1028/Centre National de la Recherche Scientifique UMR 5292, University of Lyon Lyon, France
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Captur G, Karperien AL, Hughes AD, Francis DP, Moon JC. The fractal heart - embracing mathematics in the cardiology clinic. Nat Rev Cardiol 2016; 14:56-64. [PMID: 27708281 DOI: 10.1038/nrcardio.2016.161] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
For clinicians grappling with quantifying the complex spatial and temporal patterns of cardiac structure and function (such as myocardial trabeculae, coronary microvascular anatomy, tissue perfusion, myocyte histology, electrical conduction, heart rate, and blood-pressure variability), fractal analysis is a powerful, but still underused, mathematical tool. In this Perspectives article, we explain some fundamental principles of fractal geometry and place it in a familiar medical setting. We summarize studies in the cardiovascular sciences in which fractal methods have successfully been used to investigate disease mechanisms, and suggest potential future clinical roles in cardiac imaging and time series measurements. We believe that clinical researchers can deploy innovative fractal solutions to common cardiac problems that might ultimately translate into advancements for patient care.
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Affiliation(s)
- Gabriella Captur
- UCL Biological Mass Spectrometry Laboratory, Institute of Child Health and Great Ormond Street Hospital, 30 Guilford Street, London WC1N 1EH, UK; and the NIHR University College London Hospitals Biomedical Research Centre, Tottenham Court Road, London W1T 7DN, UK
| | - Audrey L Karperien
- Centre for Research in Complex Systems, School of Community Health, Charles Sturt University, Albury, NSW 2640, Australia
| | - Alun D Hughes
- Institute of Cardiovascular Science, University College London, Gower Street, London WC1E 6BT, UK
| | - Darrel P Francis
- International Centre for Circulatory Health, National Heart and Lung Institute, Imperial College London, London SW3 6LY, UK
| | - James C Moon
- Barts Heart Centre, The Cardiovascular Magnetic Resonance Imaging Unit, St Bartholomew's Hospital, West Smithfield, London, EC1A 7BE, UK
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Stuckey MI, Kiviniemi A, Gill DP, Shoemaker JK, Petrella RJ. Associations between heart rate variability, metabolic syndrome risk factors, and insulin resistance. Appl Physiol Nutr Metab 2016; 40:734-40. [PMID: 26140416 DOI: 10.1139/apnm-2014-0528] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The purpose of this study was to examine differences in heart rate variability (HRV) in metabolic syndrome (MetS) and to determine associations between HRV parameters, MetS risk factors, and insulin resistance (homeostasis model assessment for insulin resistance (HOMA-IR)). Participants (n = 220; aged 23-70 years) were assessed for MetS risk factors (waist circumference, blood pressure, fasting plasma glucose, triglycerides, and high-density lipoprotein cholesterol) and 5-min supine HRV (time and frequency domain and nonlinear). HRV was compared between those with 3 or more (MetS+) and those with 2 or fewer MetS risk factors (MetS-). Multiple linear regression models were built for each HRV parameter to investigate associations with MetS risk factors and HOMA-IR. Data with normal distribution are presented as means ± SD and those without as median [interquartile range]. In women, standard deviation of R-R intervals 38.0 [27.0] ms, 44.5 [29.3] ms; p = 0.020), low-frequency power (5.73 ± 1.06 ln ms(2), 6.13 ± 1.05 ln ms(2); p = 0.022), and the standard deviation of the length of the Poincaré plot (46.8 [31.6] ms, 58.4 [29.9] ms; p = 0.014) were lower and heart rate was higher (68 [13] beats/min, 64 [12] beats/min; p = 0. 018) in MetS+ compared with MetS-, with no differences in men. Waist circumference was most commonly associated with HRV, especially frequency domain parameters. HOMA-IR was associated with heart rate. In conclusion, MetS+ women had a less favourable HRV profile than MetS- women, but there were no differences in men. HOMA-IR was associated with heart rate, not HRV.
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Affiliation(s)
- Melanie I Stuckey
- a Lawson Health Research Institute, Aging Rehabilitation and Geriatric Care Research Centre, 801 Commissioners Road East, London, ON N6C 5J1, Canada.,b School of Kinesiology, University of Western Ontario, London, ON, Canada
| | - Antti Kiviniemi
- c Verve Research, Department of Exercise and Medical Physiology, Kasarmintie 13, PO Box 404, FI-90101 Oulu, Finland
| | - Dawn P Gill
- a Lawson Health Research Institute, Aging Rehabilitation and Geriatric Care Research Centre, 801 Commissioners Road East, London, ON N6C 5J1, Canada.,d Faculty of Health Sciences, Western Centre for Public Health and Family Medicine, University of Western Ontario, London, ON N6A 3K7, Canada.,e School of Public Health, University of Washington, Seattle, WA 98195, USA
| | - J Kevin Shoemaker
- g School of Kinesiology, University of Western Ontario, London, ON N6A 3K7, Canada
| | - Robert J Petrella
- a Lawson Health Research Institute, Aging Rehabilitation and Geriatric Care Research Centre, 801 Commissioners Road East, London, ON N6C 5J1, Canada.,b School of Kinesiology, University of Western Ontario, London, ON, Canada.,f Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON N6A 5B9, Canada
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Jiménez-Pavón D, Artero EG, Lee DC, España-Romero V, Sui X, Pate RR, Church TS, Moreno LA, Lavie CJ, Blair SN. Cardiorespiratory Fitness and Risk of Sudden Cardiac Death in Men and Women in the United States: A Prospective Evaluation From the Aerobics Center Longitudinal Study. Mayo Clin Proc 2016; 91:849-57. [PMID: 27378037 DOI: 10.1016/j.mayocp.2016.04.025] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Revised: 03/12/2016] [Accepted: 04/12/2016] [Indexed: 11/26/2022]
Abstract
OBJECTIVES To examine the relation between cardiorespiratory fitness (CRF) and sudden cardiac death (SCD) in a large US adult population and to study the effects of hypertension, obesity, and health status on the relation of CRF with SCD. PATIENTS AND METHODS A total of 55,456 individuals (mean age, 44.2 years; 13,507 women) from the Aerobics Center Longitudinal Study, a prospective observational investigation (from January 2, 1974, through December 31, 2002), were included. Cardiorespiratory fitness was assessed by a maximal treadmill test, and baseline assessment included an extensive set of measurements. RESULTS There were 109 SCDs. An inverse risk of SCD was found across incremental CRF levels after adjusting for potential confounders. Participants with moderate and high CRF levels had 44% (hazard ratio, 0.56; 95% CI, 0.35-0.90) and 48% (hazard ratio, 0.52; 95% CI, 0.30-0.92) significantly lower risk of SCD, respectively, than did those with low CRF levels (P<.001). The risk of SCD decreased by 14% (hazard ratio, 0.86; 95% CI, 0.77-0.96) per 1-metabolic equivalent increase in the fully adjusted model. Hypertensive, overweight, or unhealthy individuals with moderate to high CRF levels had lower risks of SCD (ranging from 58% to 72% of lower risk) than did those with the same medical conditions and low CRF levels. CONCLUSION The risk of SCD in US men and women could be partially reduced by ensuring moderate to high levels of CRF independently of other risk factors and especially in those who are hypertensive, overweight, or unhealthy.
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Affiliation(s)
- David Jiménez-Pavón
- GALENO Research Group, Department of Physical Education, University of Cádiz, Puerto Real, Cádiz, Spain; Department of Exercise Science, University of South Carolina, Columbia; GENUD (Growth, Exercise, Nutrition and Development) Research Group, Faculty of Health Sciences, University of Zaragoza, Zaragoza, Spain.
| | - Enrique G Artero
- Department of Exercise Science, University of South Carolina, Columbia; Department of Education, University of Almería, Almería, Spain
| | - Duck-Chul Lee
- Department of Kinesiology, Iowa State University, Ames
| | - Vanesa España-Romero
- GALENO Research Group, Department of Physical Education, University of Cádiz, Puerto Real, Cádiz, Spain; Medical Research Council Epidemiology Unit, Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, United Kingdom
| | - Xuemei Sui
- Department of Exercise Science, University of South Carolina, Columbia
| | - Russell R Pate
- Department of Exercise Science, University of South Carolina, Columbia
| | - Timothy S Church
- Preventive Medicine Laboratory, Pennington Biomedical Research Center, Baton Rouge, LA
| | - Luis A Moreno
- GENUD (Growth, Exercise, Nutrition and Development) Research Group, Faculty of Health Sciences, University of Zaragoza, Zaragoza, Spain
| | - Carl J Lavie
- Department of Cardiovascular Diseases, John Ochsner Heart and Vascular Institute, Ochsner Clinical School-The University of Queensland's School of Medicine, New Orleans, LA
| | - Steven N Blair
- Department of Exercise Science, University of South Carolina, Columbia; Department of Epidemiology and Biostatistics, University of South Carolina, Columbia
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Hu W, Jin X, Zhang P, Yu Q, Yin G, Lu Y, Xiao H, Chen Y, Zhang D. Deceleration and acceleration capacities of heart rate associated with heart failure with high discriminating performance. Sci Rep 2016; 6:23617. [PMID: 27005970 PMCID: PMC4804298 DOI: 10.1038/srep23617] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2015] [Accepted: 03/10/2016] [Indexed: 01/06/2023] Open
Abstract
Accurate measurements of autonomic nerve regulation in heart failure (HF) were unresolved. The discriminating performance of deceleration and acceleration capacities of heart rate in HF was evaluated in 130 HF patients and 212 controls. Acceleration capacity and deceleration capacity were independent risk factors for HF in males, evaluated by multiple logistic regression analysis, with odds ratios (ORs) of 5.94 and 0.13, respectively. Acceleration capacity was also an independent risk factor for HF in females, with an OR of 8.58. Deceleration capacity was the best cardiac electrophysiological index to classify HF in males, with an area under the receiver operating characteristic curve (AUC) of 0.88. Deceleration capacity was the best classification factor of HF in females with an AUC of 0.97, significantly higher than even left ventricular ejection fraction (LVEF). Acceleration capacity also showed high performance in classifying HF in males (0.84) and females (0.92). The cut-off values of deceleration capacity for HF classification in males and females were 4.55 ms and 4.85 ms, respectively. The cut-off values of acceleration capacity for HF classification in males and females were −6.15 ms and −5.75 ms, respectively. Our study illustrates the role of acceleration and deceleration capacity measurements in the neuro-pathophysiology of HF.
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Affiliation(s)
- Wei Hu
- Department of Cardiology, the Center Hospital of Minhang District, 170 Xinsong Road, Minhang District, Shanghai 201199, China
| | - Xian Jin
- Department of Cardiology, the Center Hospital of Minhang District, 170 Xinsong Road, Minhang District, Shanghai 201199, China
| | - Peng Zhang
- Department of Cardiology, the Center Hospital of Minhang District, 170 Xinsong Road, Minhang District, Shanghai 201199, China
| | - Qiang Yu
- Department of Cardiology, the Center Hospital of Minhang District, 170 Xinsong Road, Minhang District, Shanghai 201199, China
| | - Guizhi Yin
- Department of Cardiology, the Center Hospital of Minhang District, 170 Xinsong Road, Minhang District, Shanghai 201199, China
| | - Yi Lu
- Department of Cardiology, the Center Hospital of Minhang District, 170 Xinsong Road, Minhang District, Shanghai 201199, China
| | - Hongbing Xiao
- Department of Cardiology, the Center Hospital of Minhang District, 170 Xinsong Road, Minhang District, Shanghai 201199, China
| | - Yueguang Chen
- Department of Cardiology, the Center Hospital of Minhang District, 170 Xinsong Road, Minhang District, Shanghai 201199, China
| | - Dadong Zhang
- Department of Cardiology, the Center Hospital of Minhang District, 170 Xinsong Road, Minhang District, Shanghai 201199, China
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Chiang JY, Huang JW, Lin LY, Chang CH, Chu FY, Lin YH, Wu CK, Lee JK, Hwang JJ, Lin JL, Chiang FT. Detrended Fluctuation Analysis of Heart Rate Dynamics Is an Important Prognostic Factor in Patients with End-Stage Renal Disease Receiving Peritoneal Dialysis. PLoS One 2016; 11:e0147282. [PMID: 26828209 PMCID: PMC4734614 DOI: 10.1371/journal.pone.0147282] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2015] [Accepted: 01/02/2016] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND AND OBJECTIVES Patients with severe kidney function impairment often have autonomic dysfunction, which could be evaluated noninvasively by heart rate variability (HRV) analysis. Nonlinear HRV parameters such as detrended fluctuation analysis (DFA) has been demonstrated to be an important outcome predictor in patients with cardiovascular diseases. Whether cardiac autonomic dysfunction measured by DFA is also a useful prognostic factor in patients with end-stage renal disease (ESRD) receiving peritoneal dialysis (PD) remains unclear. The purpose of the present study was designed to test the hypothesis. MATERIALS AND METHODS Patients with ESRD receiving PD were included for the study. Twenty-four hour Holter monitor was obtained from each patient together with other important traditional prognostic makers such as underlying diseases, left ventricular ejection fraction (LVEF) and serum biochemistry profiles. Short-term (DFAα1) and long-term (DFAα2) DFA as well as other linear HRV parameters were calculated. RESULTS A total of 132 patients (62 men, 72 women) with a mean age of 53.7±12.5 years were recruited from July 2007 to March 2009. During a median follow-up period of around 34 months, eight cardiac and six non-cardiac deaths were observed. Competing risk analysis demonstrated that decreased DFAα1 was a strong prognostic predictor for increased cardiac and total mortality. ROC analysis showed that the AUC of DFAα1 (<0.95) to predict mortality was 0.761 (95% confidence interval (CI). = 0.617-0.905). DFAα1≧ 0.95 was associated with lower cardiac mortality (Hazard ratio (HR) 0.062, 95% CI = 0.007-0.571, P = 0.014) and total mortality (HR = 0.109, 95% CI = 0.033-0.362, P = 0.0003). CONCLUSION Cardiac autonomic dysfunction evaluated by DFAα1 is an independent predictor for cardiac and total mortality in patients with ESRD receiving PD.
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Affiliation(s)
- Jiun-Yang Chiang
- Division of Cardiology, Department of Internal Medicine, National Taiwan University Hospital Hsin-Chu Branch, Hsin-Chu, Taiwan
| | - Jenq-Wen Huang
- Division of Nephrology, Department of Internal Medicine, National Taiwan University College of Medicine and Hospital, Taipei, Taiwan
| | - Lian-Yu Lin
- Division of Cardiology, Department of Internal Medicine, National Taiwan University College of Medicine and Hospital, Taipei, Taiwan
| | - Chin-Hao Chang
- Department of Medical Research, National Taiwan University Hospital, Taipei, Taiwan
| | - Fang-Ying Chu
- Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan
| | - Yen-Hung Lin
- Division of Cardiology, Department of Internal Medicine, National Taiwan University College of Medicine and Hospital, Taipei, Taiwan
| | - Cho-Kai Wu
- Division of Cardiology, Department of Internal Medicine, National Taiwan University College of Medicine and Hospital, Taipei, Taiwan
| | - Jen-Kuang Lee
- Division of Cardiology, Department of Internal Medicine, National Taiwan University College of Medicine and Hospital, Taipei, Taiwan
| | - Juei-Jen Hwang
- Division of Cardiology, Department of Internal Medicine, National Taiwan University College of Medicine and Hospital, Taipei, Taiwan
| | - Jiunn-Lee Lin
- Division of Cardiology, Department of Internal Medicine, National Taiwan University College of Medicine and Hospital, Taipei, Taiwan
| | - Fu-Tien Chiang
- Division of Cardiology, Department of Internal Medicine, National Taiwan University College of Medicine and Hospital, Taipei, Taiwan
- Department of Laboratory Medicine, National Taiwan University Hospital, Taipei, Taiwan
- * E-mail:
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Mazzuco A, Medeiros WM, Sperling MPR, de Souza AS, Alencar MCN, Arbex FF, Neder JA, Arena R, Borghi-Silva A. Relationship between linear and nonlinear dynamics of heart rate and impairment of lung function in COPD patients. Int J Chron Obstruct Pulmon Dis 2015; 10:1651-61. [PMID: 26316739 PMCID: PMC4544724 DOI: 10.2147/copd.s81736] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND In chronic obstructive pulmonary disease (COPD), functional and structural impairment of lung function can negatively impact heart rate variability (HRV); however, it is unknown if static lung volumes and lung diffusion capacity negatively impacts HRV responses. We investigated whether impairment of static lung volumes and lung diffusion capacity could be related to HRV indices in patients with moderate to severe COPD. METHODS Sixteen sedentary males with COPD were enrolled in this study. Resting blood gases, static lung volumes, and lung diffusion capacity for carbon monoxide (DLCO) were measured. The RR interval (RRi) was registered in the supine, standing, and seated positions (10 minutes each) and during 4 minutes of a respiratory sinus arrhythmia maneuver (M-RSA). Delta changes (Δsupine-standing and Δsupine-M-RSA) of the standard deviation of normal RRi, low frequency (LF, normalized units [nu]) and high frequency (HF [nu]), SD1, SD2, alpha1, alpha2, and approximate entropy (ApEn) indices were calculated. RESULTS HF, LF, SD1, SD2, and alpha1 deltas significantly correlated with forced expiratory volume in 1 second, DLCO, airway resistance, residual volume, inspiratory capacity/total lung capacity ratio, and residual volume/total lung capacity ratio. Significant and moderate associations were also observed between LF/HF ratio versus total gas volume (%), r=0.53; LF/HF ratio versus residual volume, %, r=0.52; and HF versus total gas volume (%), r=-0.53 (P<0.05). Linear regression analysis revealed that ΔRRi supine-M-RSA was independently related to DLCO (r=-0.77, r (2)=0.43, P<0.05). CONCLUSION Responses of HRV indices were more prominent during M-RSA in moderate to severe COPD. Moreover, greater lung function impairment was related to poorer heart rate dynamics. Finally, impaired lung diffusion capacity was related to an altered parasympathetic response in these patients.
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Affiliation(s)
- Adriana Mazzuco
- Cardiopulmonary Physiotherapy Laboratory, Federal University of São Carlos, São Carlos, Brazil
| | - Wladimir Musetti Medeiros
- Pulmonary Function and Clinical Exercise Physiology Unit, Respiratory Division, Department of Medicine, Federal University of São Paulo, São Paulo, Brazil
| | | | - Aline Soares de Souza
- Pulmonary Function and Clinical Exercise Physiology Unit, Respiratory Division, Department of Medicine, Federal University of São Paulo, São Paulo, Brazil
| | - Maria Clara Noman Alencar
- Pulmonary Function and Clinical Exercise Physiology Unit, Respiratory Division, Department of Medicine, Federal University of São Paulo, São Paulo, Brazil
| | - Flávio Ferlin Arbex
- Pulmonary Function and Clinical Exercise Physiology Unit, Respiratory Division, Department of Medicine, Federal University of São Paulo, São Paulo, Brazil
| | - José Alberto Neder
- Pulmonary Function and Clinical Exercise Physiology Unit, Respiratory Division, Department of Medicine, Federal University of São Paulo, São Paulo, Brazil
- Laboratory of Clinical Exercise Physiology, Division of Respiratory and Critical Care Medicine, Department of Medicine, Queen’s University, Kingston, ON, Canada
| | - Ross Arena
- Department of Physical Therapy and Integrative Physiology Laboratory, College of Applied Health Sciences, University of Illinois Chicago, Chicago, IL, USA
| | - Audrey Borghi-Silva
- Cardiopulmonary Physiotherapy Laboratory, Federal University of São Carlos, São Carlos, Brazil
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Sassi R, Cerutti S, Lombardi F, Malik M, Huikuri HV, Peng CK, Schmidt G, Yamamoto Y. Advances in heart rate variability signal analysis: joint position statement by the e-Cardiology ESC Working Group and the European Heart Rhythm Association co-endorsed by the Asia Pacific Heart Rhythm Society. Europace 2015; 17:1341-53. [PMID: 26177817 DOI: 10.1093/europace/euv015] [Citation(s) in RCA: 379] [Impact Index Per Article: 42.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Accepted: 01/13/2015] [Indexed: 12/18/2022] Open
Abstract
Following the publication of the Task Force document on heart rate variability (HRV) in 1996, a number of articles have been published to describe new HRV methodologies and their application in different physiological and clinical studies. This document presents a critical review of the new methods. A particular attention has been paid to methodologies that have not been reported in the 1996 standardization document but have been more recently tested in sufficiently sized populations. The following methods were considered: Long-range correlation and fractal analysis; Short-term complexity; Entropy and regularity; and Nonlinear dynamical systems and chaotic behaviour. For each of these methods, technical aspects, clinical achievements, and suggestions for clinical application were reviewed. While the novel approaches have contributed in the technical understanding of the signal character of HRV, their success in developing new clinical tools, such as those for the identification of high-risk patients, has been rather limited. Available results obtained in selected populations of patients by specialized laboratories are nevertheless of interest but new prospective studies are needed. The investigation of new parameters, descriptive of the complex regulation mechanisms of heart rate, has to be encouraged because not all information in the HRV signal is captured by traditional methods. The new technologies thus could provide after proper validation, additional physiological, and clinical meaning. Multidisciplinary dialogue and specialized courses in the combination of clinical cardiology and complex signal processing methods seem warranted for further advances in studies of cardiac oscillations and in the understanding normal and abnormal cardiac control processes.
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Acharya UR, Fujita H, Sudarshan VK, Sree VS, Eugene LWJ, Ghista DN, Tan RS. An integrated index for detection of Sudden Cardiac Death using Discrete Wavelet Transform and nonlinear features. Knowl Based Syst 2015. [DOI: 10.1016/j.knosys.2015.03.015] [Citation(s) in RCA: 86] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Multifractality in heartbeat dynamics in patients undergoing beating-heart myocardial revascularization. Comput Biol Med 2015; 60:66-73. [PMID: 25756703 DOI: 10.1016/j.compbiomed.2015.02.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Revised: 02/12/2015] [Accepted: 02/14/2015] [Indexed: 11/24/2022]
Abstract
BACKGROUND The multifractal approach of HRV analysis offers new insight into the mechanisms of autonomic modulation of the diseased hearts and has a potential to depict subtle changes in cardiac autonomic nervous control not revealed by conventional linear and non-linear analyses in various conditions like heart failure or stable angina pectoris. The aim of this study was to employ the multifractality approach in cardiac surgery patients and evaluate the multifractality before and after beating-heart myocardial revascularization (off-pump CABG). METHODS Twenty-four hour Holter recordings were performed pre- and postoperatively in 60 patients undergoing off-pump CABG. Selected conventional time- and frequency-domain linear HRV indices were calculated from the 24h and 5 min ECG segments, and preselected multifractal parameters τ(q=2), τ(q=3), h_top and Δh were determined for daytime (12:00-18:00) and nighttime (00:00-06:00) periods of the ECG recordings using Ivanov's method. Mean differences over time were tested using paired-samples t-test and exact Wilcoxon matched-pairs test. The results are reported as mean ± SD and median with interquartile range. A p value of <0.05 was considered statistically significant. RESULTS All selected conventional linear HRV parameters decreased significantly after off pump CABG (p from <0.001-0.015). Preoperatively, multifractal parameter τ(q=2) was -0.60 ± 0.12 and -0.54 ± 0.12, τ(q=3) -0.52 ± 0.18 and -0.49 ± 0.17, h_top 0.20 ± 0.07 and 0.15 ± 0.07 and Δh 0.31 ± 0.14 and 0.17 ± 0.14 for daytime and nighttime periods, respectively. Postoperatively, τ(q=2) and τ(q=3) were significantly higher for daytime (-0.49 ± 0.15, p<0.001 and -0.43 ± 0.23, p=0.015), whereas h_top and Δh were significantly higher for both daytime and nighttime (0.25 ± 0.07, p<0.001 and 0.19 ± 0.06, p=0.002 for h_top and 0.41 ± 0.20, p=0.003 and 0.31 ± 0.19, p < 0.001 for Δh, respectively). All pre- and postoperative parameters, except τ(q=2) and τ(q=3) preoperatively, were significantly lower for nighttime as compared to daytime periods. CONCLUSIONS A significant breakdown of multifractal complexity and anti-correlation behavior with a significant sympathetic overdrive and a concomitant parasympathetic withdrawal occurs after off-pump CABG. The circadian pattern of multifractality regains its day-night variation in the first week after the surgical procedure.
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Garcia-Araújo AS, Pires Di Lorenzo VA, Labadessa IG, Jürgensen SP, Di Thommazo-Luporini L, Garbim CL, Borghi-Silva A. Increased sympathetic modulation and decreased response of the heart rate variability in controlled asthma. J Asthma 2014; 52:246-53. [PMID: 25158110 DOI: 10.3109/02770903.2014.957765] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE To compare the autonomic modulation of heart rate (HR) in asthmatic and healthy volunteers to correlate it with the forced expiratory volume in the first second (FEV1). METHODS Ten healthy and 14 asthmatic volunteers were included in this cross-sectional study. The volunteers underwent a cardiopulmonary exercise test, spirometry and a register of both resting heart rate variability (HRV) in the supine and seated positions along with HRV during the respiratory sinus arrhythmia maneuver (M-RSA). RESULTS At rest in supine, asthmatic volunteers presented a higher HR (77.1 ± 9.9 vs. 68.7 ± 8.7 bpm), shorter interval between two R waves (R-Ri) (807.5 ± 107.2 vs. 887.5 ± 112.7 ms) when compared with the healthy volunteers, respectively. Moreover, in the frequency domain of HRV, there was increased low frequency (LF) index (50.4 ± 17.1 vs. 29.2 ± 11.1 n.u.) and decreased high frequency (HF) index (49.4 ± 17.1 vs. 70.7 ± 11.1 n.u.). During the M-RSA, the asthmatic presented higher HR (82.6 ± 10.0 vs. 72.4 ± 7.6 bpm) and lower values of R-Ri (746.4 ± 92.1 vs. 846.4 ± 81.4 ms) and approximate entropy (ApEn) (0.7 ± 0.0 vs. 0.8 ± 0.1). FEV1 was strongly correlated with the change of the continuous beat-to-beat variability of HR (SD2) index from the seated to the supine position (r = 0.78). CONCLUSION Controlled asthma in adults appears to induce an increased sympathetic modulation and attenuated response to the postural changes and the M-RSA. Furthermore, there is a correlation between the airways' obstruction and HRV, especially during postural changes.
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Harris PRE, Stein PK, Fung GL, Drew BJ. Heart rate variability measured early in patients with evolving acute coronary syndrome and 1-year outcomes of rehospitalization and mortality. Vasc Health Risk Manag 2014; 10:451-64. [PMID: 25143740 PMCID: PMC4132256 DOI: 10.2147/vhrm.s57524] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
OBJECTIVE This study sought to examine the prognostic value of heart rate variability (HRV) measurement initiated immediately after emergency department presentation for patients with acute coronary syndrome (ACS). BACKGROUND Altered HRV has been associated with adverse outcomes in heart disease, but the value of HRV measured during the earliest phases of ACS related to risk of 1-year rehospitalization and death has not been established. METHODS Twenty-four-hour Holter recordings of 279 patients with ACS were initiated within 45 minutes of emergency department arrival; recordings with ≥18 hours of sinus rhythm were selected for HRV analysis (number [N] =193). Time domain, frequency domain, and nonlinear HRV were examined. Survival analysis was performed. RESULTS During the 1-year follow-up, 94 patients were event-free, 82 were readmitted, and 17 died. HRV was altered in relation to outcomes. Predictors of rehospitalization included increased normalized high frequency power, decreased normalized low frequency power, and decreased low/high frequency ratio. Normalized high frequency >42 ms(2) predicted rehospitalization while controlling for clinical variables (hazard ratio [HR] =2.3; 95% confidence interval [CI] =1.4-3.8, P=0.001). Variables significantly associated with death included natural logs of total power and ultra low frequency power. A model with ultra low frequency power <8 ms(2) (HR =3.8; 95% CI =1.5-10.1; P=0.007) and troponin >0.3 ng/mL (HR =4.0; 95% CI =1.3-12.1; P=0.016) revealed that each contributed independently in predicting mortality. Nonlinear HRV variables were significant predictors of both outcomes. CONCLUSION HRV measured close to the ACS onset may assist in risk stratification. HRV cut-points may provide additional, incremental prognostic information to established assessment guidelines, and may be worthy of additional study.
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Affiliation(s)
- Patricia R E Harris
- Electrocardiographic Monitoring Research Laboratory, School of Nursing, Department of Physiological Nursing, University of California, San Francisco, CA, USA
| | - Phyllis K Stein
- Heart Rate Variability Laboratory, School of Medicine, Division of Cardiology, Washington University, St Louis, MO, USA
| | - Gordon L Fung
- Cardiology Services, Mount Zion, Department of Medicine, Division of Cardiology, University of California, San Francisco, CA, USA
| | - Barbara J Drew
- School of Nursing, Department of Physiological Nursing, Division of Cardiology, University of California, San Francisco, CA, USA
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Valera B, Suhas E, Counil E, Poirier P, Dewailly E. Influence of polyunsaturated fatty acids on blood pressure, resting heart rate and heart rate variability among French Polynesians. J Am Coll Nutr 2014; 33:288-96. [PMID: 24971659 DOI: 10.1080/07315724.2013.874913] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVE To analyze the associations between marine n-3 polyunsaturated fatty acids (PUFAs) and blood pressure (BP), resting heart rate (HR), and heart rate variability (HRV) in a population highly exposed to methylmercury through the diet. METHODS Concentrations of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) in erythrocytes membranes were measured in 180 French Polynesian adults (≥18 years) residing in Tubuai, which is a community with a traditional lifestyle, or Papeete, which has a modern lifestyle. HRV was measured using a 2-hour ambulatory electrocardiogram (Holter). Resting HR and BP were measured using standardized protocols and pulse pressure (PP) was calculated as systolic BP - diastolic BP. The associations between n-3 PUFAs and the dependent variables were studied using simple and multiple linear regressions. RESULTS Increasing DHA concentration was associated with lower resting HR (β = -2.57, p = 0.005) and diastolic BP (β = -1.96, p = 0.05) and higher HRV in multivariable models. Specifically, DHA was associated with high frequency (HF; β = 0.19, p = 0.02) and the square root of the mean squared differences of successive R-R intervals (difference between two consecutive R waves; rMSSD; β = 0.08, p = 0.03), which are specific indices of the parasympathetic activity of the autonomic nervous system. CONCLUSION DHA was associated with lower BP and resting HR and higher HRV among French Polynesians who are also exposed to high methylmercury levels.
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Affiliation(s)
- Beatriz Valera
- a Axe Santé des Populations et Environnement, Centre de Recherche du CHUQ , Quebec , CANADA (B.V., E.D.); Institut Louis Malardé , Papeete , POLYNÉSIE FRANÇAISE (E.S.); École des Hautes Études en Santé Publique, Département épidémiologie et biostatistiques , Paris , FRANCE (E.C.); IRIS , UMR 8156-997, Bobigny , FRANCE (E.C.); Quebec Heart and Lung Institute, Laval Hospital Research Centre (P.P.), Faculty of Pharmacy (P.P.), Department of Social and Preventive Medicine (E.D.), Laval University , Quebec , CANADA
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Sundman E, Olofsson PS. Neural control of the immune system. ADVANCES IN PHYSIOLOGY EDUCATION 2014; 38:135-139. [PMID: 25039084 PMCID: PMC4056170 DOI: 10.1152/advan.00094.2013] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Accepted: 03/25/2014] [Indexed: 06/02/2023]
Abstract
Neural reflexes support homeostasis by modulating the function of organ systems. Recent advances in neuroscience and immunology have revealed that neural reflexes also regulate the immune system. Activation of the vagus nerve modulates leukocyte cytokine production and alleviates experimental shock and autoimmune disease, and recent data have suggested that vagus nerve stimulation can improve symptoms in human rheumatoid arthritis. These discoveries have generated an increased interest in bioelectronic medicine, i.e., therapeutic delivery of electrical impulses that activate nerves to regulate immune system function. Here, we discuss the physiology and potential therapeutic implications of neural immune control.
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da Silva SAF, Guida HL, Dos SantosAntônio AM, Vanderlei LCM, Ferreira LL, de Abreu LC, Sousa FH, Valenti VE. Auditory stimulation with music influences the geometric indices of heart rate variability in men. Int Arch Med 2014; 7:27. [PMID: 24883104 PMCID: PMC4039650 DOI: 10.1186/1755-7682-7-27] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2013] [Accepted: 05/11/2014] [Indexed: 11/16/2022] Open
Abstract
Background Chronic classical music was reported to increase parasympathetic activitywhen evaluating heart rate variability (HRV). It is poor in the literature investigation of the acute effects of baroque and heavy metal styles of musical auditory stimulation on HRV. In this study we evaluated the acute effects of relaxant baroque and excitatory heavy metal music on the geometric indices of HRV in healthy men. Method The study was performed in 12 healthy men between 18 and 30 years old. We excluded persons with previous experience with music instrument and those who had affinity with the song styles. We analyzed the following indices: RRtri, TINN and Poincaré plot (SD1, SD2 and SD1/SD2 ratio). HRV was recorded at rest for ten minutes. Subsequently they were exposed to relaxant baroque or excitatory heavy metal music for five minutes through an earphone. After the first music exposure they remained at rest for more five minutes and them they were exposed again to Baroque or Heavy Metal music (65–80 dB). The sequence of songs was randomized for each individual. Results The RRTri and SD2 indices were reduced during the heavy metal musical auditory stimulation (p < 0.05). No changes were observed regarding TINN, SD1 and SD1/SD2 ratio (p > 0.05).The qualitative Poincaré plot analysis indicated that during relaxant classical baroque music there was observed a higher beat-to-beat dispersion of RR intervals compared with no music exposure and during excitatory heavy metal musical auditory stimulation, showing higher HRV. Conclusion We suggest that excitatory heavy metal music acutely decreases global HRV.
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Affiliation(s)
- Sheila Ap F da Silva
- Centro de Estudos do Sistema Nervoso Autônomo (CESNA), Departamento de Fonoaudiologia, Faculdade de Filosofia e Ciências, Universidade Estadual Paulista, UNESP, Av. Hygino Muzzi Filho, 737, 17525-900 Marília, SP, Brasil
| | - Heraldo L Guida
- Centro de Estudos do Sistema Nervoso Autônomo (CESNA), Departamento de Fonoaudiologia, Faculdade de Filosofia e Ciências, Universidade Estadual Paulista, UNESP, Av. Hygino Muzzi Filho, 737, 17525-900 Marília, SP, Brasil
| | - Ana M Dos SantosAntônio
- Programa de Pós-Graduação em Fisioterapia, Faculdade de Ciências e Tecnologia, Universidade Estadual Paulista (UNESP), Rua Roberto Simonsen, 305, 19060-900 Presidente Prudente, SP, Brasil
| | - Luiz Carlos M Vanderlei
- Programa de Pós-Graduação em Fisioterapia, Faculdade de Ciências e Tecnologia, Universidade Estadual Paulista (UNESP), Rua Roberto Simonsen, 305, 19060-900 Presidente Prudente, SP, Brasil
| | - Lucas L Ferreira
- Programa de Pós-Graduação em Fisioterapia, Faculdade de Ciências e Tecnologia, Universidade Estadual Paulista (UNESP), Rua Roberto Simonsen, 305, 19060-900 Presidente Prudente, SP, Brasil
| | - Luiz Carlos de Abreu
- Departamento de Morfologia e Fisiologia, Faculdade de Medicina do ABC, Av. Príncipe de Gales, 821, 09060-650 Santo André, SP, Brasil
| | - Fernando H Sousa
- Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, USP, Av. Bandeirantes, 3900, 14040-90 Ribeirão Preto, SP, Brasil
| | - Vitor E Valenti
- Centro de Estudos do Sistema Nervoso Autônomo (CESNA), Departamento de Fonoaudiologia, Faculdade de Filosofia e Ciências, Universidade Estadual Paulista, UNESP, Av. Hygino Muzzi Filho, 737, 17525-900 Marília, SP, Brasil
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Ebrahimzadeh E, Pooyan M, Bijar A. A novel approach to predict sudden cardiac death (SCD) using nonlinear and time-frequency analyses from HRV signals. PLoS One 2014; 9:e81896. [PMID: 24504331 PMCID: PMC3913584 DOI: 10.1371/journal.pone.0081896] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2012] [Accepted: 10/28/2013] [Indexed: 02/01/2023] Open
Abstract
Investigations show that millions of people all around the world die as the result of sudden cardiac death (SCD). These deaths can be reduced by using medical equipment, such as defibrillators, after detection. We need to propose suitable ways to assist doctors to predict sudden cardiac death with a high level of accuracy. To do this, Linear, Time-Frequency (TF) and Nonlinear features have been extracted from HRV of ECG signal. Finally, healthy people and people at risk of SCD are classified by k-Nearest Neighbor (k-NN) and Multilayer Perceptron Neural Network (MLP). To evaluate, we have compared the classification rates for both separate and combined Nonlinear and TF features. The results show that HRV signals have special features in the vicinity of the occurrence of SCD that have the ability to distinguish between patients prone to SCD and normal people. We found that the combination of Time-Frequency and Nonlinear features have a better ability to achieve higher accuracy. The experimental results show that the combination of features can predict SCD by the accuracy of 99.73%, 96.52%, 90.37% and 83.96% for the first, second, third and forth one-minute intervals, respectively, before SCD occurrence.
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Affiliation(s)
- Elias Ebrahimzadeh
- Department of Biomedical Engineering, Shahed University, Tehran, Iran
- * E-mail:
| | - Mohammad Pooyan
- Department of Biomedical Engineering, Shahed University, Tehran, Iran
| | - Ahmad Bijar
- Department of Biomedical Engineering, Shahed University, Tehran, Iran
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Harris PR, Sommargren CE, Stein PK, Fung GL, Drew BJ. Heart rate variability measurement and clinical depression in acute coronary syndrome patients: narrative review of recent literature. Neuropsychiatr Dis Treat 2014; 10:1335-47. [PMID: 25071372 PMCID: PMC4111661 DOI: 10.2147/ndt.s57523] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
AIM We aimed to explore links between heart rate variability (HRV) and clinical depression in patients with acute coronary syndrome (ACS), through a review of recent clinical research literature. BACKGROUND Patients with ACS are at risk for both cardiac autonomic dysfunction and clinical depression. Both conditions can negatively impact the ability to recover from an acute physiological insult, such as unstable angina or myocardial infarction, increasing the risk for adverse cardiovascular outcomes. HRV is recognized as a reflection of autonomic function. METHODS A narrative review was undertaken to evaluate state-of-the-art clinical research, using the PubMed database, January 2013. The search terms "heart rate variability" and "depression" were used in conjunction with "acute coronary syndrome", "unstable angina", or "myocardial infarction" to find clinical studies published within the past 10 years related to HRV and clinical depression, in patients with an ACS episode. Studies were included if HRV measurement and depression screening were undertaken during an ACS hospitalization or within 2 months of hospital discharge. RESULTS Nine clinical studies met the inclusion criteria. The studies' results indicate that there may be a relationship between abnormal HRV and clinical depression when assessed early after an ACS event, offering the possibility that these risk factors play a modest role in patient outcomes. CONCLUSION While a definitive conclusion about the relevance of HRV and clinical depression measurement in ACS patients would be premature, the literature suggests that these measures may provide additional information in risk assessment. Potential avenues for further research are proposed.
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Affiliation(s)
- Patricia Re Harris
- ECG Monitoring Research Lab, University of California, San Francisco, CA, USA
| | - Claire E Sommargren
- Department of Physiological Nursing, School of Nursing, University of California, San Francisco, CA, USA
| | - Phyllis K Stein
- Heart Rate Variability Laboratory, School of Medicine, Washington University, St Louis, MO, USA
| | - Gordon L Fung
- Asian Heart & Vascular Center at Mount Zion, Division of Cardiology, University of California, San Francisco, CA, USA ; Cardiology Consultation Service, Cardiac Noninvasive Laboratory, and The Enhanced External Counterpulsation Unit, Department of Medicine, University of California, San Francisco Medical Center, San Francisco, CA, USA
| | - Barbara J Drew
- Division of Cardiology, University of California, San Francisco, CA, USA ; Department of Physiological Nursing, School of Nursing, University of California, San Francisco, CA, USA
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Voss A, Schroeder R, Vallverdú M, Schulz S, Cygankiewicz I, Vázquez R, Bayés de Luna A, Caminal P. Short-term vs. long-term heart rate variability in ischemic cardiomyopathy risk stratification. Front Physiol 2013; 4:364. [PMID: 24379785 PMCID: PMC3862074 DOI: 10.3389/fphys.2013.00364] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2013] [Accepted: 11/23/2013] [Indexed: 01/08/2023] Open
Abstract
In industrialized countries with aging populations, heart failure affects 0.3–2% of the general population. The investigation of 24 h-ECG recordings revealed the potential of nonlinear indices of heart rate variability (HRV) for enhanced risk stratification in patients with ischemic heart failure (IHF). However, long-term analyses are time-consuming, expensive, and delay the initial diagnosis. The objective of this study was to investigate whether 30 min short-term HRV analysis is sufficient for comparable risk stratification in IHF in comparison to 24 h-HRV analysis. From 256 IHF patients [221 at low risk (IHFLR) and 35 at high risk (IHFHR)] (a) 24 h beat-to-beat time series (b) the first 30 min segment (c) the 30 min most stationary day segment and (d) the 30 min most stationary night segment were investigated. We calculated linear (time and frequency domain) and nonlinear HRV analysis indices. Optimal parameter sets for risk stratification in IHF were determined for 24 h and for each 30 min segment by applying discriminant analysis on significant clinical and non-clinical indices. Long- and short-term HRV indices from frequency domain and particularly from nonlinear dynamics revealed high univariate significances (p < 0.01) discriminating between IHFLR and IHFHR. For multivariate risk stratification, optimal mixed parameter sets consisting of 5 indices (clinical and nonlinear) achieved 80.4% AUC (area under the curve of receiver operating characteristics) from 24 h HRV analysis, 84.3% AUC from first 30 min, 82.2 % AUC from daytime 30 min and 81.7% AUC from nighttime 30 min. The optimal parameter set obtained from the first 30 min showed nearly the same classification power when compared to the optimal 24 h-parameter set. As results from stationary daytime and nighttime, 30 min segments indicate that short-term analyses of 30 min may provide at least a comparable risk stratification power in IHF in comparison to a 24 h analysis period.
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Affiliation(s)
- Andreas Voss
- Department of Medical Engineering and Biotechnology, University of Applied Sciences Jena, Germany
| | - Rico Schroeder
- Department of Medical Engineering and Biotechnology, University of Applied Sciences Jena, Germany
| | - Montserrat Vallverdú
- Biomedical Engineering Research Centre, Universitat Politècnica de Catalunya Barcelona, Spain
| | - Steffen Schulz
- Department of Medical Engineering and Biotechnology, University of Applied Sciences Jena, Germany
| | - Iwona Cygankiewicz
- Department of Electrocardiology, Sterling Memorial University Hospital Lodz, Poland
| | - Rafael Vázquez
- Servicio de Cardiología, Puerta del Mar University Hospital Cádiz, Spain
| | | | - Pere Caminal
- Biomedical Engineering Research Centre, Universitat Politècnica de Catalunya Barcelona, Spain
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Södervall J, Karppinen J, Puolitaival J, Kyllönen E, Kiviniemi AM, Tulppo MP, Hautala AJ. Heart rate variability in sciatica patients referred to spine surgery: a case control study. BMC Musculoskelet Disord 2013; 14:149. [PMID: 23622100 PMCID: PMC3644230 DOI: 10.1186/1471-2474-14-149] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2012] [Accepted: 04/23/2013] [Indexed: 01/30/2023] Open
Abstract
BACKGROUND A chronic pain condition may result in altered autonomic nervous system regulation in various patient populations. We evaluated whether autonomic regulation differs between sciatica patients referred to spine surgery and age-matched healthy controls analyzed with heart rate variability techniques (HRV). METHODS HRV of patients (n = 201) and healthy controls (n = 138) were measured in standing conditions (5 min). High frequency (HF) power as an index of cardiac vagal modulation and the low-to-high-frequency (LF/HF) ratio and short-term fractal scaling exponent α1 as indices of sympathovagal balance were analyzed. Pain intensity was assessed on a Visual Analog Scale (VAS) and perceived disability with Oswestry Disability Index. RESULTS The Oswestry and VAS scores were higher in the patients than in the controls (p < 0.0001 for both). HF power was markedly lower for the patients compared to the controls (p < 0.0001). The LF/HF ratio and α1 were higher in the patients than in the controls (p < 0.01 for both). After adjusting for sex, smoking, BMI, and leisure-time physical activity, HF power (p = 0.011) and α1 (p = 0.012) still differed between the groups. Among the patients, HF power was slightly associated with the duration of chronic pain (r = -.232, p = 0.003). CONCLUSIONS Sciatica patients referred to spine surgery had altered cardiac autonomic regulation expressed as decreased vagal activity and an increased sympathovagal balance toward sympathetic dominance when compared with age-matched healthy controls.
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Pittman-Polletta BR, Scheer FAJL, Butler MP, Shea SA, Hu K. The role of the circadian system in fractal neurophysiological control. Biol Rev Camb Philos Soc 2013; 88:873-94. [PMID: 23573942 DOI: 10.1111/brv.12032] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2012] [Revised: 02/20/2013] [Accepted: 02/21/2013] [Indexed: 01/31/2023]
Abstract
Many neurophysiological variables such as heart rate, motor activity, and neural activity are known to exhibit intrinsic fractal fluctuations - similar temporal fluctuation patterns at different time scales. These fractal patterns contain information about health, as many pathological conditions are accompanied by their alteration or absence. In physical systems, such fluctuations are characteristic of critical states on the border between randomness and order, frequently arising from nonlinear feedback interactions between mechanisms operating on multiple scales. Thus, the existence of fractal fluctuations in physiology challenges traditional conceptions of health and disease, suggesting that high levels of integrity and adaptability are marked by complex variability, not constancy, and are properties of a neurophysiological network, not individual components. Despite the subject's theoretical and clinical interest, the neurophysiological mechanisms underlying fractal regulation remain largely unknown. The recent discovery that the circadian pacemaker (suprachiasmatic nucleus) plays a crucial role in generating fractal patterns in motor activity and heart rate sheds an entirely new light on both fractal control networks and the function of this master circadian clock, and builds a bridge between the fields of circadian biology and fractal physiology. In this review, we sketch the emerging picture of the developing interdisciplinary field of fractal neurophysiology by examining the circadian system's role in fractal regulation.
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Affiliation(s)
- Benjamin R Pittman-Polletta
- Medical Biodynamics Program, Division of Sleep Medicine, Brigham and Women's Hospital, Boston, MA, 02115, U.S.A.; Medical Chronobiology Program, Division of Sleep Medicine, Brigham and Women's Hospital, Boston, MA, 02115, U.S.A.; Division of Sleep Medicine, Harvard Medical School, Boston, MA, 02115, U.S.A
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Abstract
The monitoring of intracranial pressure (ICP) is an important tool in medicine for its ability to portray the brain’s compliance status. The bedside monitor displays the ICP waveform and intermittent mean values to guide physicians in the management of patients, particularly those having sustained a traumatic brain injury. Researchers in the fields of engineering and physics have investigated various mathematical analysis techniques applicable to the waveform in order to extract additional diagnostic and prognostic information, although they largely remain limited to research applications. The purpose of this review is to present the current techniques used to monitor and interpret ICP and explore the potential of using advanced mathematical techniques to provide information about system perturbations from states of homeostasis. We discuss the limits of each proposed technique and we propose that nonlinear analysis could be a reliable approach to describe ICP signals over time, with the fractal dimension as a potential predictive clinically meaningful biomarker. Our goal is to stimulate translational research that can move modern analysis of ICP using these techniques into widespread practical use, and to investigate to the clinical utility of a tool capable of simplifying multiple variables obtained from various sensors.
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Affiliation(s)
- Antonio Di Ieva
- Department of Surgery, Division of Neurosurgery, St. Michael’s Hospital, University of Toronto, Toronto, ON, Canada
- Injury Prevention Research Office, St. Michael’s Hospital, Toronto, ON, Canada
| | - Erika M. Schmitz
- Injury Prevention Research Office, St. Michael’s Hospital, Toronto, ON, Canada
| | - Michael D. Cusimano
- Department of Surgery, Division of Neurosurgery, St. Michael’s Hospital, University of Toronto, Toronto, ON, Canada
- Injury Prevention Research Office, St. Michael’s Hospital, Toronto, ON, Canada
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Hillebrand S, Gast KB, de Mutsert R, Swenne CA, Jukema JW, Middeldorp S, Rosendaal FR, Dekkers OM. Heart rate variability and first cardiovascular event in populations without known cardiovascular disease: meta-analysis and dose-response meta-regression. Europace 2013; 15:742-9. [PMID: 23370966 DOI: 10.1093/europace/eus341] [Citation(s) in RCA: 289] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
AIMS Heart rate variability (HRV) is associated with cardiovascular disease (CVD) in individuals with known CVD. It is less clear whether HRV is associated with a first cardiovascular event. Therefore, we performed a meta-analysis to study the association between HRV and incident cardiovascular events in populations without known CVD. METHODS AND RESULTS We performed a meta-analysis and dose-response meta-regression of studies assessing the association between HRV and CVD. We searched Pubmed, Embase, Web of Science, Cochrane library, ScienceDirect, and CINAHL up to December 2011 for eligible studies. We selected studies that used the standard deviation of the normalized N-N interval (SDNN), low-frequency (LF) or high-frequency (HF) spectral component as a measure of HRV. Primary outcomes were (non)fatal cardiovascular events. Eight studies with a total number of 21 988 participants were included. The pooled relative risk (RR) comparing the lowest level to the highest level of SDNN was 1.35 (95% CI 1.10, 1.67). The pooled RRs for LF and HF were 1.45 (95% CI 1.12, 1.87) and 1.32 (95% CI 0.96, 1.81), respectively. In a meta-regression, the predicted RR of incident CVD of the 10th and 90th HRV (SDNN) percentiles compared with the 50th percentile were 1.50 (95% CI 1.22, 1.83) and 0.67 (95% CI 0.41, 1.09). CONCLUSION In conclusion, low HRV is associated with a 32-45% increased risk of a first cardiovascular event in populations without known CVD. An increase in SDNN of 1% results in an ∼1% lower risk of fatal or non-fatal CVD.
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Affiliation(s)
- Stefanie Hillebrand
- Department of Clinical Epidemiology, Leiden University Medical Centre, Albinusdreef 2, Leiden, The Netherlands
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Valera B, Dewailly E, Poirier P. Association between methylmercury and cardiovascular risk factors in a native population of Quebec (Canada): a retrospective evaluation. ENVIRONMENTAL RESEARCH 2013; 120:102-108. [PMID: 22959488 DOI: 10.1016/j.envres.2012.08.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2012] [Revised: 07/24/2012] [Accepted: 08/02/2012] [Indexed: 06/01/2023]
Abstract
BACKGROUND Epidemiological evidence suggests a negative impact of methylmercury (MeHg) on cardiovascular risk factors such as blood pressure (BP) and heart rate (HR). This issue is of concern in Arctic populations such as in the Inuit of Nunavik since this contaminant is accumulated in fish and marine mammals, which still represent the subsistence diet of this population. OBJECTIVE We examined the associations between MeHg and BP and resting HR among Inuit adults. METHODS The "Santé Quebec" health survey was conducted in 1992 in the 14 villages of Nunavik and a complete set of data was obtained for 313 Inuit adults≥18 years. Blood samples were collected in order to determine total mercury, lead, total polychlorinated biphenyls (PCBs), n-3 polyunsaturated fatty acids (PUFAs), fasting glucose and lipid profile while socio-demographic variables were obtained through questionnaires. Anthropometric measurements as well as BP and resting HR were obtained using standardised protocols. Pulse pressure (PP: systolic BP minus diastolic BP) was also calculated. Multiple linear regression was used in order to determine the change in the dependent variables associated with the quartiles of MeHg concentration, taking the quartile 1 as reference. RESULTS The mean age of the participants was 38±14 years and the sample was composed of 132 men (42.2%) and 181 women (57.8%). MeHg geometric mean was 15.4 μg/L (95%CI: 13.9-17.0) and levels ranged from 0.8 to 112.0 μg/L. Resting HR increased linearly across quartiles of blood MeHg concentration after adjusting for confounders (p for trend=0.02). An increase of 6.9 beats per minute (bpm) between the 4th and 1st quartile was observed after adjusting for confounders. No significant association was observed between blood MeHg and systolic BP, diastolic BP or PP. CONCLUSIONS MeHg was associated with increasing resting HR after considering traditional risk factors as well as other contaminants (lead and total PCBs) and n-3 PUFAs. In contrast, no significant association with blood pressure was observed in this study.
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Affiliation(s)
- Beatriz Valera
- Axe santé des populations et environnementale, Centre de recherche du CHUQ, Édifice Delta 2, 2875, boulevard Laurier, 6e étage, Sainte-Foy, Québec, Canada G1V 2M2.
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Muralikrishnan K, Balakrishnan B, Balasubramanian K, Visnegarawla F. Measurement of the effect of Isha Yoga on cardiac autonomic nervous system using short-term heart rate variability. J Ayurveda Integr Med 2012; 3:91-6. [PMID: 22707866 PMCID: PMC3371565 DOI: 10.4103/0975-9476.96528] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Revised: 03/30/2012] [Accepted: 04/20/2012] [Indexed: 11/26/2022] Open
Abstract
Background: Beneficial effects of Yoga have been postulated to be due to modulation of the autonomic nervous system. Objective: To assess the effect of Isha Yoga practices on cardiovascular autonomic nervous system through short-term heart rate variability (HRV). Design of the Study: Short-term HRV of long-term regular healthy 14 (12 males and 2 females) Isha Yoga practitioners was compared with that of age- and gender-matched 14 (12 males and 2 females) non-Yoga practitioners. Methods and Materials: ECG Lead II and respiratory movements were recorded in both groups using Polyrite during supine rest for 5 min and controlled deep breathing for 1 minute. Frequency domain analysis [RR interval is the mean of distance between subsequent R wave peaks in ECG], low frequency (LF) power, high frequency (HF) power, LF normalized units (nu), HF nu, LF/HF ratio] and time domain analysis [Standard Deviation of normal to normal interval (SDNN), square of mean squared difference of successive normal to normal intervals (RMSSD), normal to normal intervals which are differing by 50 ms (NN50), and percentage of NN50 (pNN50)] of HRV variables were analyzed for supine rest. Time domain analysis was recorded for deep breathing. Results: Results showed statistically significant differences between Isha Yoga practitioners and controls in both frequency and time domain analyses of HRV indices, with no difference in resting heart rate between the groups. Conclusions: Practitioners of Isha Yoga showed well-balanced beneficial activity of vagal efferents, an overall increased HRV, and sympathovagal balance, compared to non-Yoga practitioners during supine rest and deep breathing.
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Valera B, Muckle G, Poirier P, Jacobson SW, Jacobson JL, Dewailly E. Cardiac autonomic activity and blood pressure among Inuit children exposed to mercury. Neurotoxicology 2012; 33:1067-74. [DOI: 10.1016/j.neuro.2012.05.005] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Bardai A, Lamberts RJ, Blom MT, Spanjaart AM, Berdowski J, van der Staal SR, Brouwer HJ, Koster RW, Sander JW, Thijs RD, Tan HL. Epilepsy is a risk factor for sudden cardiac arrest in the general population. PLoS One 2012; 7:e42749. [PMID: 22916156 PMCID: PMC3419243 DOI: 10.1371/journal.pone.0042749] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2011] [Accepted: 07/12/2012] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND People with epilepsy are at increased risk for sudden death. The most prevalent cause of sudden death in the general population is sudden cardiac arrest (SCA) due to ventricular fibrillation (VF). SCA may contribute to the increased incidence of sudden death in people with epilepsy. We assessed whether the risk for SCA is increased in epilepsy by determining the risk for SCA among people with active epilepsy in a community-based study. METHODS AND RESULTS This investigation was part of the Amsterdam Resuscitation Studies (ARREST) in the Netherlands. It was designed to assess SCA risk in the general population. All SCA cases in the study area were identified and matched to controls (by age, sex, and SCA date). A diagnosis of active epilepsy was ascertained in all cases and controls. Relative risk for SCA was estimated by calculating the adjusted odds ratios using conditional logistic regression (adjustment was made for known risk factors for SCA). We identified 1019 cases of SCA with ECG-documented VF, and matched them to 2834 controls. There were 12 people with active epilepsy among cases and 12 among controls. Epilepsy was associated with a three-fold increased risk for SCA (adjusted OR 2.9 [95%CI 1.1-8.0.], p=0.034). The risk for SCA in epilepsy was particularly increased in young and females. CONCLUSION Epilepsy in the general population seems to be associated with an increased risk for SCA.
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Affiliation(s)
- Abdennasser Bardai
- Heart Failure Research Center, University of Amsterdam, Amsterdam, The Netherlands
- Interuniversity Cardiology Institute Netherlands, Utrecht, The Netherlands
| | - Robert J. Lamberts
- SEIN- Epilepsy Institute in The Netherlands Foundation, Heemstede, The Netherlands
| | - Marieke T. Blom
- Heart Failure Research Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Anne M. Spanjaart
- Heart Failure Research Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Jocelyn Berdowski
- Department of Cardiology, University of Amsterdam, Amsterdam, The Netherlands
| | | | - Henk J. Brouwer
- Department of General Practice, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Rudolph W. Koster
- Department of Cardiology, University of Amsterdam, Amsterdam, The Netherlands
| | - Josemir W. Sander
- SEIN- Epilepsy Institute in The Netherlands Foundation, Heemstede, The Netherlands
- Department of Clinical and Experimental Epilepsy, University College London Institute of Neurology, Queen Square, London, United Kingdom
| | - Roland D. Thijs
- SEIN- Epilepsy Institute in The Netherlands Foundation, Heemstede, The Netherlands
- Department of Neurology, Leiden University Medical Center, Leiden, The Netherlands
- Department of Clinical and Experimental Epilepsy, University College London Institute of Neurology, Queen Square, London, United Kingdom
| | - Hanno L. Tan
- Heart Failure Research Center, University of Amsterdam, Amsterdam, The Netherlands
- Department of Cardiology, University of Amsterdam, Amsterdam, The Netherlands
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Murad K, Brubaker PH, Fitzgerald DM, Morgan TM, Goff DC, Soliman EZ, Eggebeen JD, Kitzman DW. Exercise training improves heart rate variability in older patients with heart failure: a randomized, controlled, single-blinded trial. ACTA ACUST UNITED AC 2012; 18:192-7. [PMID: 22536936 DOI: 10.1111/j.1751-7133.2011.00282.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Reduced heart rate variability (HRV) in older patients with heart failure (HF) is common and indicates poor prognosis. Exercise training (ET) has been shown to improve HRV in younger patients with HF. However, the effect of ET on HRV in older patients with HF is not known. Sixty-six participants (36% men), aged 69±5 years, with HF and both preserved ejection fraction (HFPEF) and reduced ejection fraction (HFREF), were randomly assigned to 16 weeks of supervised ET (ET group) vs attention-control (AC group). Two HRV parameters (the standard deviation of all normal RR intervals [SDNN] and the root mean square of successive differences in normal RR intervals [RMSSD]) were measured at baseline and after completion of the study. When compared with the AC group, the ET group had a significantly greater increase in both SDNN (15.46±5.02 ms in ET vs 2.37±2.13 ms in AC, P=.016) and RMSSD (17.53±7.83 ms in ET vs 1.69±2.63 ms in AC, P=.003). This increase was seen in both sexes and HF categories. ET improved HRV in older patients with both HFREF and HFPEF.
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Affiliation(s)
- Khalil Murad
- Internal Medicine, Wake Forest University School of Medicine, Winston-Salem, NC, USA.
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NICOLINI PAOLA, CIULLA MICHELEM, ASMUNDIS CARLODE, MAGRINI FABIO, BRUGADA PEDRO. The Prognostic Value of Heart Rate Variability in the Elderly, Changing the Perspective: From Sympathovagal Balance to Chaos Theory. PACING AND CLINICAL ELECTROPHYSIOLOGY: PACE 2012; 35:622-38. [DOI: 10.1111/j.1540-8159.2012.03335.x] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Lin DC, Sharif A. Integrated central-autonomic multifractal complexity in the heart rate variability of healthy humans. Front Physiol 2012; 2:123. [PMID: 22403548 PMCID: PMC3277279 DOI: 10.3389/fphys.2011.00123] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2011] [Accepted: 12/28/2011] [Indexed: 11/25/2022] Open
Abstract
PURPOSE OF STUDY The aim of this study was to characterize the central-autonomic interaction underlying the multifractality in heart rate variability (HRV) of healthy humans. MATERIALS AND METHODS Eleven young healthy subjects participated in two separate ~40 min experimental sessions, one in supine (SUP) and one in, head-up-tilt (HUT), upright (UPR) body positions. Surface scalp electroencephalography (EEG) and electrocardiogram (ECG) were collected and fractal correlation of brain and heart rate data was analyzed based on the idea of relative multifractality. The fractal correlation was further examined with the EEG, HRV spectral measures using linear regression of two variables and principal component analysis (PCA) to find clues for the physiological processing underlying the central influence in fractal HRV. RESULTS We report evidence of a central-autonomic fractal correlation (CAFC) where the HRV multifractal complexity varies significantly with the fractal correlation between the heart rate and brain data (P = 0.003). The linear regression shows significant correlation between CAFC measure and EEG Beta band spectral component (P = 0.01 for SUP and P = 0.002 for UPR positions). There is significant correlation between CAFC measure and HRV LF component in the SUP position (P = 0.04), whereas the correlation with the HRV HF component approaches significance (P = 0.07). The correlation between CAFC measure and HRV spectral measures in the UPR position is weak. The PCA results confirm these findings and further imply multiple physiological processes underlying CAFC, highlighting the importance of the EEG Alpha, Beta band, and the HRV LF, HF spectral measures in the supine position. DISCUSSION AND CONCLUSION The findings of this work can be summarized into three points: (i) Similar fractal characteristics exist in the brain and heart rate fluctuation and the change toward stronger fractal correlation implies the change toward more complex HRV multifractality. (ii) CAFC is likely contributed by multiple physiological mechanisms, with its central elements mainly derived from the EEG Alpha, Beta band dynamics. (iii) The CAFC in SUP and UPR positions is qualitatively different, with a more predominant central influence in the fractal HRV of the UPR position.
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Affiliation(s)
- D. C. Lin
- Department of Mechanical and Industrial Engineering, Ryerson UniversityToronto, ON, Canada
| | - A. Sharif
- Department of Mechanical and Industrial Engineering, Ryerson UniversityToronto, ON, Canada
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Abstract
Heart rate variability (HRV), the beat-to-beat variation in either heart rate or the duration of the R-R interval - the heart period, has become a popular clinical and investigational tool. The temporal fluctuations in heart rate exhibit a marked synchrony with respiration (increasing during inspiration and decreasing during expiration - the so called respiratory sinus arrhythmia, RSA) and are widely believed to reflect changes in cardiac autonomic regulation. Although the exact contributions of the parasympathetic and the sympathetic divisions of the autonomic nervous system to this variability are controversial and remain the subject of active investigation and debate, a number of time and frequency domain techniques have been developed to provide insight into cardiac autonomic regulation in both health and disease. It is the purpose of this essay to provide an historical overview of the evolution in the concept of HRV. Briefly, pulse rate was first measured by ancient Greek physicians and scientists. However, it was not until the invention of the "Physician's Pulse Watch" (a watch with a second hand that could be stopped) in 1707 that changes in pulse rate could be accurately assessed. The Rev. Stephen Hales (1733) was the first to note that pulse varied with respiration and in 1847 Carl Ludwig was the first to record RSA. With the measurement of the ECG (1895) and advent of digital signal processing techniques in the 1960s, investigation of HRV and its relationship to health and disease has exploded. This essay will conclude with a brief description of time domain, frequency domain, and non-linear dynamic analysis techniques (and their limitations) that are commonly used to measure HRV.
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Affiliation(s)
- George E. Billman
- Department of Physiology and Cell Biology, The Ohio State UniversityColumbus, OH, USA
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Valera B, Dewailly É, Poirier P, Counil E, Suhas E. Influence of mercury exposure on blood pressure, resting heart rate and heart rate variability in French Polynesians: a cross-sectional study. Environ Health 2011; 10:99. [PMID: 22078280 PMCID: PMC3228671 DOI: 10.1186/1476-069x-10-99] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2011] [Accepted: 11/13/2011] [Indexed: 05/04/2023]
Abstract
BACKGROUND Populations which diet is rich in seafood are highly exposed to contaminants such as mercury, which could affect cardiovascular risk factors OBJECTIVE To assess the associations between mercury and blood pressure (BP), resting heart rate (HR) and HR variability (HRV) among French Polynesians METHODS Data were collected among 180 adults (≥ 18 years) and 101 teenagers (12-17 years). HRV was measured using a two-hour ambulatory electrocardiogram (Holter) and BP was measured using a standardized protocol. The association between mercury and HRV and BP parameters was studied using analysis of variance (ANOVA) and analysis of covariance (ANCOVA) RESULTS: Among teenagers, the high frequency (HF) decreased between the 2nd and 3rd tertile (380 vs. 204 ms2, p = 0.03) and a similar pattern was observed for the square root of the mean squared differences of successive R-R intervals (rMSSD) (43 vs. 30 ms, p = 0.005) after adjusting for confounders. In addition, the ratio low/high frequency (LF/HF) increased between the 2nd and 3rd tertile (2.3 vs. 3.0, p = 0.04). Among adults, the standard deviation of R-R intervals (SDNN) tended to decrease between the 1st and 2nd tertile (84 vs. 75 ms, p = 0.069) after adjusting for confounders. Furthermore, diastolic BP tended to increase between the 2nd and 3rd tertile (86 vs. 91 mm Hg, p = 0.09). No significant difference was observed in resting HR or pulse pressure (PP) CONCLUSIONS: Mercury was associated with decreased HRV among French Polynesian teenagers while no significant association was observed with resting HR, BP, or PP among teenagers or adults.
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Affiliation(s)
- Beatriz Valera
- Axe Santé des Populations et Environnement, Centre de Recherche du CHUQ, 2875 Boulevard Laurier, Québec, G1V 2M2, Canada
| | - Éric Dewailly
- Axe Santé des Populations et Environnement, Centre de Recherche du CHUQ, 2875 Boulevard Laurier, Québec, G1V 2M2, Canada
- Department of Social and Preventive Medicine, Laval University, 1050 avenue de la Médecine, Quebec, G1V 0A6, Canada
| | - Paul Poirier
- Quebec Heart and Lung Institute, Laval Hospital Research Centre, 2725 Chemin Sainte-Foy, Québec, G1V 4G5, Canada
- Faculty of Pharmacy, Laval University, 1050 avenue de la Médecine, Quebec, G1V 0A6, Canada
| | - Emilie Counil
- Département Épidémiologie et Biostatistiques, École des Hautes Études en Santé Publique, Hôtel-Dieu, 1, place Notre-Dame, Paris Cedex 4, 75181, France
- Université Paris 13, GISCOP93, UFR SMBH, 74, rue Marcel Cachin, Bobigny Cedex, 93017, France
| | - Edouard Suhas
- Unité de maladies non transmissibles (LMNT), Institut Louis Malardé, rue du 5 mars 1797, Papeete, 98713, Polynésie Française
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Perkiömäki JS. Heart rate variability and non-linear dynamics in risk stratification. Front Physiol 2011; 2:81. [PMID: 22084633 PMCID: PMC3210967 DOI: 10.3389/fphys.2011.00081] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2011] [Accepted: 10/21/2011] [Indexed: 01/12/2023] Open
Abstract
The time-domain measures and power–spectral analysis of heart rate variability (HRV) are classic conventional methods to assess the complex regulatory system between autonomic nervous system and heart rate and are most widely used. There are abundant scientific data about the prognostic significance of the conventional measurements of HRV in patients with various conditions, particularly with myocardial infarction. Some studies have suggested that some newer measures describing non-linear dynamics of heart rate, such as fractal measures, may reveal prognostic information beyond that obtained by the conventional measures of HRV. An ideal risk indicator could specifically predict sudden arrhythmic death as the implantable cardioverter-defibrillator (ICD) therapy can prevent such events. There are numerically more sudden deaths among post-infarction patients with better preserved left ventricular function than in those with severe left ventricular dysfunction. Recent data support the concept that HRV measurements, when analyzed several weeks after acute myocardial infarction, predict life-threatening ventricular tachyarrhythmias in patients with moderately depressed left ventricular function. However, well-designed prospective randomized studies are needed to evaluate whether the ICD therapy based on the assessment of HRV alone or with other risk indicators improves the patients’ prognosis. Several issues, such as the optimal target population, optimal timing of HRV measurements, optimal methods of HRV analysis, and optimal cutpoints for different HRV parameters, need clarification before the HRV analysis can be a widespread clinical tool in risk stratification.
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Affiliation(s)
- Juha S Perkiömäki
- Institute of Clinical Medicine, Division of Cardiology, Department of Internal Medicine, Centre of Excellence in Research, University of Oulu Oulu, Finland
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Shin DG, Lee SH, Yi SH, Yoo CS, Hong GR, Kim U, Park JS, Kim YJ. Breakdown of the intermediate-term fractal scaling exponent in sinus node dysfunction. New method for non-invasive evaluation of sinus node function. Circ J 2011; 75:2775-80. [PMID: 21946356 DOI: 10.1253/circj.cj-11-0641] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND The aim of the present study was to characterize the heart rate dynamics of sinus bradycardia (SB) from sinus node dysfunction (SND) using non-linear dynamical system analysis. No data are yet available on how the dynamics change in the presence of SND. METHODS AND RESULTS Conventional time and frequency domain analysis, the short- (DFAα(1)) and intermediate-term fractal scaling exponent (DFAα(2)), approximate entropy (ApEn) and sample entropy (SampEn) were calculated in 60-min sinus RR interval data of SB from 24-h ambulatory electrocardiograms of 110 patients: 44 SND patients, 44 age-matched controls, and 22 younger controls. All of the time and frequency domain parameters, ApEn and SampEn, were significantly reduced in the age-matched control group, compared with the young control group. DFAα(1) and DFAα(2) increased with aging. Both the DFAα(1) and DFAα(2) of SND patients were paradoxically reduced, which was not appropriate for their age. Only the percentage of consecutive RR intervals with absolute differences >50ms (pNN(50)), low-frequency power, and DFAα(2) made a significant contribution to prediction of SND on logistic regression analysis. Among them, DFAα(2) was the most significant variable for prediction of SND (odds ratio, 0.927; 95% confidence interval: 0.888-0.969, P=0.001). DFAα(2) remained as a significant variable for prediction of SND, when compared with overall control patients, combining the 2 control groups. CONCLUSIONS Inappropriate reduction of DFAα(2) is a robust measure and could be an adjunctive tool for improvement of diagnostic performance in detection of SND.
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Affiliation(s)
- Dong-Gu Shin
- Cardiovascular Division, Internal Medicine, Yeungnam University Hospital, Daegu, South Korea.
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Chen Y, Chen W. Long-Term Tracking of a Patient’s Health Condition Based on Pulse Rate Dynamics During Sleep. Ann Biomed Eng 2011; 39:2922-34. [DOI: 10.1007/s10439-011-0397-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2011] [Accepted: 09/05/2011] [Indexed: 10/17/2022]
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Mateo M, Blasco-Lafarga C, Martínez-Navarro I, Guzmán JF, Zabala M. Heart rate variability and pre-competitive anxiety in BMX discipline. Eur J Appl Physiol 2011; 112:113-23. [PMID: 21503698 DOI: 10.1007/s00421-011-1962-8] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2010] [Accepted: 04/04/2011] [Indexed: 10/18/2022]
Abstract
Altered neural mechanisms implying autonomic functioning have been described related to anxiety. Pre-competitive stress may be considered as an anxiety-state associated with disorders (i.e. somatic and cognitive alterations, and self-confidence worsening) that severely impair sport performance, conditioning short-lasting strength-related disciplines like BMX. From the psychological perspective, coaches use questionnaires like CSAI-2R to identify these alterations. However, with the emergence of psycho-physiological and non-linear approaches, recent studies suggest that HRV analysis provides a non-invasive tool to assess them. Hence, our purpose was to analyze how BMX competition affects subjective perception of anxiety, and if this emotional alteration is reflected in HR dynamics, analyzed both linear and nonlinearly, exploring the evolution of this relationship in a 2-day competition. Eleven male athletes from the BMX Spanish National Team were assessed from baseline HRV the morning of a training session (rT) and on two successive days of competition (rC1 and rC2), repeating HRV recording with CSAI-2R 20 min prior to training (aT) and competition (pre-competitive: aC1 and aC2). Repeated measures MANOVA showed significant vagal slow-down responses in aC1 and aC2 comparing not only with aT, but also comparing with rT, rC1 and rC2, coinciding with significant greater scores for the somatic and cognitive anxiety (SA and CA) in aC1 and aC2 versus aT. Pearson analysis showed a large and positive correlation between α1 and SA in C1, and close to it between SampEn and CA in aC2; both were confirmed by Bland-Altman chart analysis. Our results confirm that HRV analysis provide a complementary tool to assess competitive pressure.
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Dietert RR. Fractal immunology and immune patterning: potential tools for immune protection and optimization. J Immunotoxicol 2011; 8:101-10. [PMID: 21428733 DOI: 10.3109/1547691x.2011.559951] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Fractals are self-similar geometric patterns that are inherently embedded throughout nature. Their discovery and application have produced significant benefits across a wide variety of biomedical applications. Recently, complex physiological systems (e.g., neurological, respiratory, cardiovascular) have been shown to exhibit fractal dimensions that are capable of distinguishing among physiologic function versus dysfunction and, in turn, health versus disease. Additionally, fractal data suggest that the immune system operates under similar patterned relationships, and this is in keeping with the recent findings that immune-based diseases are organized according to specific patterns. This review considers the potential benefits of using fractal analysis along with considerations of nonlinearity, scaling, and chaos as calibration tools to obtain holistic information on immune-environment interactions. The potential uses of both synthetic and artificial immune systems for improved protection of the biological immune system are also discussed. The addition of holistic measures of immune status to currently collected biomarkers of immunotoxicity has the potential to increase the effectiveness of health risk assessment. The objective of extending fractal physiology analyses to the immune system would be to promote immune optimization as a public health benefit, which would include improved: (1) immunotoxicity testing and effective health risk reduction and (2) measures of effective immune management for children, adults, and aged individuals.
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Affiliation(s)
- Rodney R Dietert
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853, USA.
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Tulppo MP, Kiviniemi AM, Hautala AJ, Kallio M, Seppänen T, Tiinanen S, Mäkikallio TH, Huikuri HV. Sympatho-vagal interaction in the recovery phase of exercise. Clin Physiol Funct Imaging 2011; 31:272-81. [PMID: 21672134 DOI: 10.1111/j.1475-097x.2011.01012.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Reciprocal autonomic regulation occurs during incremental exercise. We hypothesized that sympatho-vagal interplay may become altered after exercise because of the differences in recovery patterns of autonomic arms. The cardiac vagal activity was assessed by measurement of beat-to-beat R-R interval oscillations using a Poincaré plot method (SD1), and muscle sympathetic nervous activity (MSNA) was measured from peroneus nerve by a microneurography technique during and after exercise in 16 healthy subjects. Autonomic regulation was compared between the rest and after exercise (3·5 ± 1·0 min after exercise) at equal heart rates (HR). SD1 was at the equal level at the recovery phase (40 ± 21 ms) compared to the resting condition (38 ± 16 ms, P = ns) at comparable HR (57 ± 10 for both). MSNA was higher at the recovery phase (40 ± 19 burst per 100 heartbeats) than at rest (25 ± 13 burst per 100 heartbeats, P<0·0001). The difference of MSNA activity between rest and late recovery phase had a strong positive correlation with the difference in SD1 (r = 0·78, P<0·001) at equal HRs. Subjects who have a higher sympathetic activity in the recovery phase of exercise have a more augmented cardiac vagal activity resulting in an accentuated sympatho-vagal outflow. The altered autonomic interaction observed here may partly explain the clustering of various cardiovascular events to the recovery phase of exercise.
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Affiliation(s)
- Mikko P Tulppo
- Department of Exercise and Medical Physiology, Verve, Oulu, Finland.
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Long-range correlation properties in motor timing are individual and task specific. Psychon Bull Rev 2011; 18:339-46. [DOI: 10.3758/s13423-011-0049-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Pantoni C, Di Thommazo L, Mendes R, Catai A, Luzzi S, Amaral Neto O, Borghi-Silva A. Effects of different levels of positive airway pressure on breathing pattern and heart rate variability after coronary artery bypass grafting surgery. Braz J Med Biol Res 2011; 44:38-45. [DOI: 10.1590/s0100-879x2010007500129] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2010] [Accepted: 10/29/2010] [Indexed: 11/21/2022] Open
Affiliation(s)
| | | | | | - A.M. Catai
- Universidade Federal de São Carlos, Brasil
| | - S. Luzzi
- Irmandade da Santa Casa de Misericórdia de Araraquara, Brasil
| | - O. Amaral Neto
- Irmandade da Santa Casa de Misericórdia de Araraquara, Brasil
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90
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10.3389/fphys.2011.00081" />
Abstract
The time-domain measures and power-spectral analysis of heart rate variability (HRV) are classic conventional methods to assess the complex regulatory system between autonomic nervous system and heart rate and are most widely used. There are abundant scientific data about the prognostic significance of the conventional measurements of HRV in patients with various conditions, particularly with myocardial infarction. Some studies have suggested that some newer measures describing non-linear dynamics of heart rate, such as fractal measures, may reveal prognostic information beyond that obtained by the conventional measures of HRV. An ideal risk indicator could specifically predict sudden arrhythmic death as the implantable cardioverter-defibrillator (ICD) therapy can prevent such events. There are numerically more sudden deaths among post-infarction patients with better preserved left ventricular function than in those with severe left ventricular dysfunction. Recent data support the concept that HRV measurements, when analyzed several weeks after acute myocardial infarction, predict life-threatening ventricular tachyarrhythmias in patients with moderately depressed left ventricular function. However, well-designed prospective randomized studies are needed to evaluate whether the ICD therapy based on the assessment of HRV alone or with other risk indicators improves the patients' prognosis. Several issues, such as the optimal target population, optimal timing of HRV measurements, optimal methods of HRV analysis, and optimal cutpoints for different HRV parameters, need clarification before the HRV analysis can be a widespread clinical tool in risk stratification.
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Affiliation(s)
- Juha S Perkiömäki
- Institute of Clinical Medicine, Division of Cardiology, Department of Internal Medicine, Centre of Excellence in Research, University of Oulu Oulu, Finland
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91
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Abstract
Heart rate variability (HRV), the beat-to-beat variation in either heart rate or the duration of the R-R interval - the heart period, has become a popular clinical and investigational tool. The temporal fluctuations in heart rate exhibit a marked synchrony with respiration (increasing during inspiration and decreasing during expiration - the so called respiratory sinus arrhythmia, RSA) and are widely believed to reflect changes in cardiac autonomic regulation. Although the exact contributions of the parasympathetic and the sympathetic divisions of the autonomic nervous system to this variability are controversial and remain the subject of active investigation and debate, a number of time and frequency domain techniques have been developed to provide insight into cardiac autonomic regulation in both health and disease. It is the purpose of this essay to provide an historical overview of the evolution in the concept of HRV. Briefly, pulse rate was first measured by ancient Greek physicians and scientists. However, it was not until the invention of the "Physician's Pulse Watch" (a watch with a second hand that could be stopped) in 1707 that changes in pulse rate could be accurately assessed. The Rev. Stephen Hales (1733) was the first to note that pulse varied with respiration and in 1847 Carl Ludwig was the first to record RSA. With the measurement of the ECG (1895) and advent of digital signal processing techniques in the 1960s, investigation of HRV and its relationship to health and disease has exploded. This essay will conclude with a brief description of time domain, frequency domain, and non-linear dynamic analysis techniques (and their limitations) that are commonly used to measure HRV.
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Affiliation(s)
- George E Billman
- Department of Physiology and Cell Biology, The Ohio State University Columbus, OH, USA
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92
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Voss A, Schroeder R, Caminal P, Vallverdú M, Brunel H, Cygankiewicz I, Vázquez R, Luna ABD. Segmented Symbolic Dynamics for Risk Stratification in Patients with Ischemic Heart Failure. Cardiovasc Eng Technol 2010. [DOI: 10.1007/s13239-010-0025-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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93
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Donaldson SG, Van Oostdam J, Tikhonov C, Feeley M, Armstrong B, Ayotte P, Boucher O, Bowers W, Chan L, Dallaire F, Dallaire R, Dewailly E, Edwards J, Egeland GM, Fontaine J, Furgal C, Leech T, Loring E, Muckle G, Nancarrow T, Pereg D, Plusquellec P, Potyrala M, Receveur O, Shearer RG. Environmental contaminants and human health in the Canadian Arctic. THE SCIENCE OF THE TOTAL ENVIRONMENT 2010; 408:5165-5234. [PMID: 20728918 DOI: 10.1016/j.scitotenv.2010.04.059] [Citation(s) in RCA: 163] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2009] [Revised: 04/23/2010] [Accepted: 04/29/2010] [Indexed: 05/29/2023]
Abstract
The third Canadian Arctic Human Health Assessment conducted under the Canadian Northern Contaminants Program (NCP), in association with the circumpolar Arctic Monitoring and Assessment Programme (AMAP), addresses concerns about possible adverse health effects in individuals exposed to environmental contaminants through a diet containing country foods. The objectives here are to: 1) provide data on changes in human contaminant concentrations and exposure among Canadian Arctic peoples; 2) identify new contaminants of concern; 3) discuss possible health effects; 4) outline risk communication about contaminants in country food; and 5) identify knowledge gaps for future contaminant research and monitoring. The nutritional and cultural benefits of country foods are substantial; however, some dietary studies suggest declines in the amount of country foods being consumed. Significant declines were found for most contaminants in maternal blood over the last 10 years within all three Arctic regions studied. Inuit continue to have the highest levels of almost all persistent organic pollutants (POPs) and metals among the ethnic groups studied. A greater proportion of people in the East exceed Health Canada's guidelines for PCBs and mercury, although the proportion of mothers exceeding these guidelines has decreased since the previous assessment. Further monitoring and research are required to assess trends and health effects of emerging contaminants. Infant development studies have shown possible subtle effects of prenatal exposure to heavy metals and some POPs on immune system function and neurodevelopment. New data suggest important beneficial effects on brain development for Inuit infants from some country food nutrients. The most successful risk communication processes balance the risks and benefits of a diet of country food through input from a variety of regional experts and the community, to incorporate the many socio-cultural and economic factors to arrive at a risk management decision that will be the most beneficial in Arctic communities.
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Affiliation(s)
- S G Donaldson
- Chemicals Surveillance Bureau, HECSB, Health Canada, 269 Laurier Ave West, Ottawa, ON, Canada K1A 0K9
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94
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Cardiorespiratory Fitness Is Related to the Risk of Sudden Cardiac Death. J Am Coll Cardiol 2010; 56:1476-83. [DOI: 10.1016/j.jacc.2010.05.043] [Citation(s) in RCA: 127] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2010] [Revised: 04/20/2010] [Accepted: 05/03/2010] [Indexed: 01/12/2023]
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95
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Kang HG, Mahoney DF, Hoenig H, Hirth VA, Bonato P, Hajjar I, Lipsitz LA. In situ monitoring of health in older adults: technologies and issues. J Am Geriatr Soc 2010; 58:1579-86. [PMID: 20646105 DOI: 10.1111/j.1532-5415.2010.02959.x] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
With the upcoming reform of the healthcare system and the greater emphasis on care in the home and other living environments, geriatric providers will need alternate ways of monitoring disease, activity, response to therapy, and patient safety. Current understanding of the dynamic nature of chronic illnesses, their effects on health over time, and the ability to manage them in the community are limited to measuring a set of variables at discrete points in time, which does not account for the dynamic interactions between physiological systems and the environments of daily life. Recent developments of sensors, data recorders, and communication networks allow the unprecedented measurements of physiological and sociological data for use in geriatrics care. This article identifies and discusses the important issues regarding the use of monitoring technologies in elderly patients. The goals are fourfold. First, some emerging technology that may improve the lives of older adults and improve care are highlighted. Second, the possible applications of technology in geriatrics settings are discussed, with a focus on acute falls, dementia, and cardiac conditions. Third, real and perceived concerns in using monitoring technology are identified and addressed, including technology adoption by elderly people; stigma; and the reduction in social contact; ethical concerns of privacy, autonomy, and consent; concerns of clinicians, including information overload, licensure, and liability; current reimbursement schemes for using technology; and the reliability and infrastructure needed for monitoring technology. Fourth, future approaches to make monitoring technology useful and available in geriatrics are recommended.
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Affiliation(s)
- Hyun Gu Kang
- Kinesiology and Health Promotion, California State Polytechnic University, Pomona, California 91768, USA.
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96
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Lin DC, Sharif A. Common multifractality in the heart rate variability and brain activity of healthy humans. CHAOS (WOODBURY, N.Y.) 2010; 20:023121. [PMID: 20590317 DOI: 10.1063/1.3427639] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The influence from the central nervous system on the human multifractal heart rate variability (HRV) is examined under the autonomic nervous system perturbation induced by the head-up-tilt body maneuver. We conducted the multifractal factorization analysis to factor out the common multifractal factor in the joint fluctuation of the beat-to-beat heart rate and electroencephalography data. Evidence of a central link in the multifractal HRV was found, where the transition towards increased (decreased) HRV multifractal complexity is associated with a stronger (weaker) multifractal correlation between the central and autonomic nervous systems.
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Affiliation(s)
- D C Lin
- Department of Mechanical and Industrial Engineering, Ryerson University, Toronto, Ontario M5B 2K3, Canada.
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97
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Hautala AJ, Karjalainen J, Kiviniemi AM, Kinnunen H, Mäkikallio TH, Huikuri HV, Tulppo MP. Physical activity and heart rate variability measured simultaneously during waking hours. Am J Physiol Heart Circ Physiol 2009; 298:H874-80. [PMID: 20023121 DOI: 10.1152/ajpheart.00856.2009] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Heart rate (HR) variability (HRV) during ambulatory recordings may be affected by individual differences in daily physical activity (PA). However, the influence of various levels of PA on different measures of HRV is not exactly known. We examined the association between simultaneously measured HRV and objective PA data obtained with an accelerometer during waking hours among 45 healthy adults. Bouts of PA were identified from minute-by-minute accelerometer data as metabolic equivalent (METs) values and calculated as mean METs for 30 min. HRV was analyzed concurrently. Within-individual correlation analyses and sign tests were performed to study the relationships between various HRV indexes and PA. The mean PA time was 15:44 +/- 1:01 h, and the mean MET was 1.91 +/- 0.14. HR and sample entropy, but not the other measures of HRV, had a significant relationship with PA, as shown by both correlation analyses (r = 0.64, P = 0.021, and r = -0.55, P = 0.022, respectively) and sign tests (P < 0.0001 for both). Beat-to-beat R-R interval fluctuation expressed as SD1 also demonstrated a significant relation to PA according to the sign test (P = 0.037) and a trend of association according to the correlation analysis (r = -0.40, P = 0.129). The complexity measure of HRV, in addition to average HR and the short-term index of HRV (SD1), is significantly influenced by the level of PA during ambulatory conditions. Long-term HRV indexes remained relatively stable at various activity levels, making them the most robust indexes for the assessment of cardiac autonomic function during free-running ambulatory conditions.
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Affiliation(s)
- Arto J Hautala
- Dept. of Exercise and Medical Physiology, Verve Research, Oulu, Finland.
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98
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Ksela J, Kalisnik JM, Avbelj V, Suwalski P, Suwalski G, Gersak B. Ventricular arrhythmic disturbances and autonomic modulation after beating-heart revascularization in patients with pulmonary normotension. Wien Klin Wochenschr 2009; 121:324-9. [PMID: 19562295 DOI: 10.1007/s00508-009-1183-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND De-novo ventricular arrhythmias are potentially life-threatening complications after beating-heart revascularization (off-pump CABG). Whether pulmonary hypertension can influence initiation of ventricular arrhythmias through increased sympathetic activity is controversial. In order to determine the influence of pulmonary hypertension on its relative contribution to ventricular arrhythmia, we first had to define the role of cardiac autonomic modulation in patients with pulmonary normotension. We aimed to observe how parameters of linear and nonlinear heart rate variability are changed pre- and postoperatively in patients with pulmonary normotension undergoing off-pump CABG. METHODS Fifteen-minute ECG recordings were collected before and after off-pump CABG in 54 patients with multivessel coronary artery disease and pulmonary normotension to determine linear (TP, HF, LF, LF:HF ratio) and nonlinear detrended fluctuation analysis (alpha1, alpha2) and fractal dimension (average, high and low) parameters of heart rate variability. Arrhythmia was monitored preoperatively in 24-hour Holter recordings and postoperatively by continuous monitoring and clinical assessment. RESULTS Deterioration from simple (Lown I-II) to complex (Lown III-V) ventricular arrhythmia was observed in 19 patients, and improvement from complex to simple arrhythmia in five patients (P = 0.022). Patients with postoperative deterioration of ventricular arrhythmia had preoperatively significantly lower values of TP, HF and LF (P = 0.024-0.043) and postoperatively significantly higher values on the low fractal dimension index (P = 0.031) than patients with postoperative improvement of arrhythmia. CONCLUSION Patients experiencing postoperative deterioration of ventricular arrhythmia already have impaired autonomic regulation before surgery. Higher postoperative values on the low fractal dimension index indicate that sympathetic predominance with or without concomitant vagal withdrawal is the underlying neurogenic mechanism contributing to ventricular arrhythmia.
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Affiliation(s)
- Jus Ksela
- Department of Cardiac Surgery, University Clinical Center Maribor, Slovenia
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99
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Sharma V. Deterministic chaos and fractal complexity in the dynamics of cardiovascular behavior: perspectives on a new frontier. Open Cardiovasc Med J 2009; 3:110-23. [PMID: 19812706 PMCID: PMC2757669 DOI: 10.2174/1874192400903010110] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2009] [Revised: 08/24/2009] [Accepted: 08/27/2009] [Indexed: 01/19/2023] Open
Abstract
Physiological systems such as the cardiovascular system are capable of five kinds of behavior: equilibrium, periodicity, quasi-periodicity, deterministic chaos and random behavior. Systems adopt one or more these behaviors depending on the function they have evolved to perform. The emerging mathematical concepts of fractal mathematics and chaos theory are extending our ability to study physiological behavior. Fractal geometry is observed in the physical structure of pathways, networks and macroscopic structures such the vasculature and the His-Purkinje network of the heart. Fractal structure is also observed in processes in time, such as heart rate variability. Chaos theory describes the underlying dynamics of the system, and chaotic behavior is also observed at many levels, from effector molecules in the cell to heart function and blood pressure. This review discusses the role of fractal structure and chaos in the cardiovascular system at the level of the heart and blood vessels, and at the cellular level. Key functional consequences of these phenomena are highlighted, and a perspective provided on the possible evolutionary origins of chaotic behavior and fractal structure. The discussion is non-mathematical with an emphasis on the key underlying concepts.
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Affiliation(s)
- Vijay Sharma
- Division of Pharmacology and Toxicology, Faculty of Pharmaceutical Sciences, The University of British Columbia, 2146 East Mall, Vancouver, Canada.
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100
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Perkiömäki JS, Mäkikallio TH, Huikuri HV. Fractal and Complexity Measures of Heart Rate Variability. Clin Exp Hypertens 2009. [DOI: 10.1081/ceh-48742] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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