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Sample records for heart rate feedback

  1. Effects of heartbeat feedback on beliefs about heart rate and heartbeat counting: a cautionary tale about interoceptive awareness.

    Science.gov (United States)

    Ring, Christopher; Brener, Jasper; Knapp, Kelley; Mailloux, Jennifer

    2015-01-01

    Heartbeat counting improves after exposure to heartbeat feedback either because feedback trains individuals to detect heartbeats or updates their knowledge/beliefs about heart rate. These possibilities were examined by assessing heartbeat counting, in different postures and following exercise, before and after exposure to immediate and delayed heartbeat feedback. Immediate and delayed feedback provided accurate information about heart rate and, therefore, either could update beliefs about heart rate. However, only immediate feedback marked each ventricular contraction and, thereby, could train participants to detect the beating of the heart by focusing attention on relevant internal sensations. Exposure to immediate and delayed feedback resulted in similar, significant increases in the accuracy of heartbeat counting, indicating that the feedback effect was mediated by non-sensory processes rather than by training participants to detect heartbeat sensations. The current findings demonstrate that the heartbeat counting task is not a valid method to assess cardioception. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Methylphenidate improves diminished error and feedback sensitivity in ADHD: An evoked heart rate analysis.

    Science.gov (United States)

    Groen, Yvonne; Mulder, Lambertus J M; Wijers, Albertus A; Minderaa, Ruud B; Althaus, Monika

    2009-09-01

    Attention Deficit Hyperactivity Disorder (ADHD) is a developmental disorder that has previously been related to a decreased sensitivity to errors and feedback. Supplementary to the traditional performance measures, this study uses autonomic measures to study this decreased sensitivity in ADHD and the modulating effects of medication. Children with ADHD, on and off Methylphenidate (Mph), and typically developing (TD) children performed a selective attention task with three feedback conditions: reward, punishment and no feedback. Evoked Heart Rate (EHR) responses were computed for correct and error trials. All groups performed more efficiently with performance feedback than without. EHR analyses, however, showed that enhanced EHR decelerations on error trials seen in TD children, were absent in the medication-free ADHD group for all feedback conditions. The Mph-treated ADHD group showed 'normalised' EHR decelerations to errors and error feedback, depending on the feedback condition. This study provides further evidence for a decreased physiological responsiveness to errors and error feedback in children with ADHD and for a modulating effect of Mph.

  3. A heart rate analysis of developmental change in feedback processing and rule shifting from childhood to early adulthood

    NARCIS (Netherlands)

    E.A. Crone (Eveline); R.J.M. Somsen (Riek); K. Zanolie (Kiki); M.W. Molen, van der (Maurits)

    2008-01-01

    textabstractOver the course of development, the ability to switch between diVerent tasks on the basis of feedback cues increases profoundly, but the role of performance monitoring remains unclear. Heart rate indexes can provide critical information about how individuals monitor feedback cues

  4. False Heart Rate Feedback and the Perception of Heart Symptoms in Patients with Congenital Heart Disease and Anxiety

    NARCIS (Netherlands)

    Karsdorp, Petra A.; Kindt, Merel; Rietveld, Simon; Everaerd, Walter; Mulder, Barbara J. M.

    2009-01-01

    Background Little is known about the mechanisms explaining an increased perception of heart symptoms in congenital heart disease (ConHD). In the present study, it was suggested that a combination of high trait anxiety and disease history increases the perception of heart symptoms. Purpose It was

  5. False heart rate feedback and the perception of heart symptoms in patients with congenital heart disease and anxiety

    NARCIS (Netherlands)

    Karsdorp, P.A.; Kindt, M.; Rietveld, S.; Everaerd, W.; Mulder, B.J.M.

    2009-01-01

    Background: Little is known about the mechanisms explaining an increased perception of heart symptoms in congenital heart disease (ConHD). In the present study, it was suggested that a combination of high trait anxiety and disease history increases the perception of heart symptoms. Purpose: It was

  6. Decomposing developmental differences in probabilistic feedback learning: A combined performance and heart-rate analysis

    NARCIS (Netherlands)

    van Duijvenvoorde, A.C.K.; Jansen, B.R.J.; Griffioen, E.S.; van der Molen, M.W.; Huizenga, H.M.

    2013-01-01

    Learning on the basis of outcome feedback shows pronounced developmental changes, however, much is still unknown about its underlying processes. In the current study, we aimed at decomposing how value updating, feedback monitoring and executing behavioral control contribute to children's

  7. Methylphenidate improves diminished error and feedback sensitivity in ADHD : An Evoked Heart Rate analysis

    NARCIS (Netherlands)

    Groen, Yvonne; Mulder, Lambertus J. M.; Wijers, Albertus A.; Minderaa, Ruud B.; Althaus, Monika

    Attention Deficit Hyperactivity Disorder (ADHD) is a developmental disorder that has previously been related to a decreased sensitivity to errors and feedback. Supplementary to the traditional performance measures, this study uses autonomic measures to study this decreased sensitivity in ADHD and

  8. iHeartLift: a closed loop system with bio-feedback that uses music tempo variability to improve heart rate variability.

    Science.gov (United States)

    Ho, Thomas C T; Chen, Xiang

    2011-01-01

    "Musica delenit bestiam feram" translates into "Music soothes the savage beast". There is a hidden truth in this ancient quip passed down from generations. Besides soothing the heart, it also incites the heart to a healthier level of heart rate variability (HRV). In this paper, an approach to use and test music and biofeedback to increase the heart rate variability for people facing daily stress is discussed. By determining the music tempo variability (MTV) of a piece of music and current heart rate variability, iHeartLift is able to compare the 2 trends and locate a musical piece that is suited to increase the user's heart rate variability to a healthier level. With biofeedback, the 2 trends are continuously compared in real-time and the musical piece is changed in accordance with the current comparisons. A study was conducted and it was generally found that HRV can be uplifted by music regardless of language and meaning of musical lyrics but with limitations to musical genre.

  9. Heart rate index

    DEFF Research Database (Denmark)

    Haedersdal, C; Pedersen, F H; Svendsen, J H

    1992-01-01

    after the myocardial infarction. A significant correlation (Spearman's correlation coefficient rs, p less than 0.05) was found between LVEF at rest and the following variables assessed at exercise test: 1) the heart rate at rest, 2) rise in heart rate, 3) ratio between maximal heart rate and heart rate...... at rest, 4) rise in systolic blood pressure, 5) rate pressure product at rest, 6) rise in rate pressure product, 7) ratio (rHR) between maximal rate pressure product and rate pressure product at rest, 8) total exercise time. The heart rate was corrected for effects caused by age (heart index (HR...

  10. Heart rate turbulence.

    Science.gov (United States)

    Cygankiewicz, Iwona

    2013-01-01

    Heart rate turbulence (HRT) is a baroreflex-mediated biphasic reaction of heart rate in response to premature ventricular beats. Heart rate turbulence is quantified by: turbulence onset (TO) reflecting the initial acceleration of heart rate following premature beat and turbulence slope (TS) describing subsequent deceleration of heart rate. Abnormal HRT identifies patients with autonomic dysfunction or impaired baroreflex sensitivity due to variety of disorders, but also may reflect changes in autonomic nervous system induced by different therapeutic modalities such as drugs, revascularization, or cardiac resynchronization therapy. More importantly, impaired HRT has been shown to identify patients at high risk of all-cause mortality and sudden death, particularly in postinfarction and congestive heart failure patients. It should be emphasized that abnormal HRT has a well-established role in stratification of postinfarction and heart failure patients with relatively preserved left ventricular ejection fraction. The ongoing clinical trials will document whether HRT can be used to guide implantation of cardioverter-defibrillators in this subset of patients, not covered yet by ICD guidelines. This review focuses on the current state-of-the-art knowledge regarding clinical significance of HRT in detection of autonomic dysfunction and regarding the prognostic significance of this parameter in predicting all-cause mortality and sudden death. © 2013.

  11. Fetal heart rate monitoring.

    Science.gov (United States)

    Nageotte, Michael P

    2015-06-01

    Electronic fetal heart rate monitoring is a widely utilized means of assessment of fetal status during labor. Whereas little evidence exists regarding efficacy, this modality continues to be used extensively in every modern labor and delivery unit in developed countries. It is of importance that all providers of health care to the woman in labor and her newborn have a clear understanding of the basic pathophysiology of fetal heart rate monitoring and an appreciation for labor course and concerns as they arise in order to optimize outcomes and patient safety. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Blood Pressure vs. Heart Rate

    Science.gov (United States)

    ... Venous Thromboembolism Aortic Aneurysm More Blood Pressure vs. Heart Rate (Pulse) Updated:Sep 15,2017 Understanding the difference ... your blood moving through your blood vessels, your heart rate is the number of times your heart beats ...

  13. Modelling Heart Rate Kinetics

    Science.gov (United States)

    Zakynthinaki, Maria S.

    2015-01-01

    The objective of the present study was to formulate a simple and at the same time effective mathematical model of heart rate kinetics in response to movement (exercise). Based on an existing model, a system of two coupled differential equations which give the rate of change of heart rate and the rate of change of exercise intensity is used. The modifications introduced to the existing model are justified and discussed in detail, while models of blood lactate accumulation in respect to time and exercise intensity are also presented. The main modification is that the proposed model has now only one parameter which reflects the overall cardiovascular condition of the individual. The time elapsed after the beginning of the exercise, the intensity of the exercise, as well as blood lactate are also taken into account. Application of the model provides information regarding the individual’s cardiovascular condition and is able to detect possible changes in it, across the data recording periods. To demonstrate examples of successful numerical fit of the model, constant intensity experimental heart rate data sets of two individuals have been selected and numerical optimization was implemented. In addition, numerical simulations provided predictions for various exercise intensities and various cardiovascular condition levels. The proposed model can serve as a powerful tool for a complete means of heart rate analysis, not only in exercise physiology (for efficiently designing training sessions for healthy subjects) but also in the areas of cardiovascular health and rehabilitation (including application in population groups for which direct heart rate recordings at intense exercises are not possible or not allowed, such as elderly or pregnant women). PMID:25876164

  14. Target Heart Rates

    Science.gov (United States)

    ... is your level of intensity? When is the best time of day to work out? Target Heart Rates Warm Up, Cool Down See More >> Getting Active Getting Started - Tips for Long-term Exercise Success Get Moving: Easy Tips to Get Active! ...

  15. Heart rate and reinforcement sensitivity in ADHD

    NARCIS (Netherlands)

    Luman, M.; Oosterlaan, J.; Hyde, C.; van Meel, C.S.; Sergeant, J.A.

    2007-01-01

    Background: Both theoretical and clinical accounts of attention-deficit/ hyperactivity disorder (ADHD) implicate a dysfunctional reinforcement system. This study investigated heart rate parameters in response to feedback associated with reward and response cost in ADHD children and controls aged 8

  16. Tachycardia | Fast Heart Rate

    Science.gov (United States)

    ... tachycardia occurs less commonly with: Heart attack Serious mitral valve disease Symptoms and Complications of Atrial or SVT Some ... tachycardia occurs less commonly with: Heart attack Serious mitral valve disease Symptoms and Complications of Atrial or SVT Some ...

  17. Effects of Liraglutide on Heart Rate and Heart Rate Variability

    DEFF Research Database (Denmark)

    Kumarathurai, Preman; Anholm, Christian; Larsen, Bjørn Strøier

    2017-01-01

    OBJECTIVE: Reduced heart rate variability (HRV) and increased heart rate (HR) have been associated with cardiovascular mortality. Glucagon-like peptide 1 receptor agonists (GLP-1 RAs) increase HR, and studies have suggested that they may reduce HRV. We examined the effect of the GLP-1 RA...

  18. Target Heart Rates

    Science.gov (United States)

    ... Research Educator CPR & ECC Shop Causes Advocate Giving Media Healthy Eating Nutrition The American Heart Association's Diet and Lifestyle ... Keep It Off Recognizing Roadblocks in Weight Loss Eating When Not Hungry Keeping the Weight ... Stress With Healthy Habits Take Action to Control Stress 3 Tips to ...

  19. Heart rate response to breathing

    DEFF Research Database (Denmark)

    Mehlsen, J; Pagh, K; Nielsen, J S

    1987-01-01

    Heart rate responses to stepwise and periodic changes in lung volume were studied in seven young healthy males. Stepwise inspiration and expiration both resulted in an increase in heart rate followed by a rapid decrease in heart rate. The fastest heart rate was reached in 1.6 +/- 0.5 s and in 3.......6 +/- 1.4 s in response to inspiration and expiration, respectively (P less than 0.01). The slowest heart rate was reached in 4.8 +/- 1.0 s and in 7.6 +/- 1.9 s in response to inspiration and expiration, respectively (P less than 0.01). Following this biphasic change the heart rate returned to a steady...... level. The difference between the fastest and the slowest heart rates was significantly larger in response to inspiration (21.7 +/- 7.3 beats per minute) than in response to expiration (12.0 +/- 7.3 beats per minute; P less than 0.01). Periodic changes in lung volume were performed with frequencies from...

  20. All about Heart Rate (Pulse)

    Science.gov (United States)

    ... result of taking a drug such as a beta blocker . A lower heart rate is also common for ... 100. Medication use: Meds that block your adrenaline (beta blockers) tend to slow your pulse, while too much ...

  1. For gold, heart rate matters.

    Science.gov (United States)

    Surmely, Jean-François; Mohacsi, Paul; Schmid, Jean-Paul; Carrel, Thierry; Delacretaz, Etienne

    2005-08-01

    A 19-year-old woman presented with decreased exercise tolerance 3 years after orthotopic heart transplantation. Exercise capacity was severely reduced, with a maximal workload of 84 W, corresponding to 56% of the predicted value. After exclusion of other causes, insufficient heart rate response to exercise was considered as the major contributor to her decreased exercise tolerance. Correction of this problem with the implantation of an AAIR pacemaker dramatically improved her physical performance, allowing her to win 5 gold medals at the European Heart and Lung Transplant Games. This case report illustrates how pacemaker therapy can dramatically improve the symptoms and performance of patients with chronotropic incompetence.

  2. Potassium supplementation and heart rate

    NARCIS (Netherlands)

    Gijsbers, L.; Molenberg, Famke; Bakker, S.J.L.; Geleijnse, J.M.

    2016-01-01

    Background and aims: Increasing the intake of potassium has been shown to lower blood pressure, but whether it also affects heart rate (HR) is largely unknown. We therefore assessed the effect of potassium supplementation on HR in a meta-analysis of randomized controlled trials. Methods and

  3. Heart rate differences in small sided games in formative basketball

    Directory of Open Access Journals (Sweden)

    Fernando Gracia

    2014-03-01

    Full Text Available The aim of this study was to determine and learn the heart rate responses of basketball players in small-sided or modified games, in order to develop a more effective workout plan in the future. The study sample consisted of 19 basketball players from a National Championship Club, 12 of them in the U’14 category and the remaining 7 belonging to the U’16 category. Small-sided games were 3x3 and 4x4 with a duration of 4 minutes and an active break of 3 minutes. Significant differences (p<0.05 were found referring to the relations established between 3x3 without feedback and 3x3 with feedback in vigorous exercise; in 3x3 without feedback and 3x3 with feedback in moderate exercise; in 3x3 and 3x3 with average heart rate; in 4x4 and 4x4 with average heart rate and in 4x4 and 4x4 with average heart rate related to game categories.Keywords:

  4. Functionality of the baroreceptor nerves in heart rate regulation

    DEFF Research Database (Denmark)

    Ottesen, Johnny T.; Olufsen, Mette

    2011-01-01

    are a consequence of the memory encapsulated by the models, and the nonlinearity gives rise to sigmoidal response curves. The nonlinear afferent baroreceptor models are coupled with an effector model, and the coupled model has been used to predict baroreceptor feedback regulation of heart rate during postural...

  5. [Resting heart rate and cardiovascular disease].

    Science.gov (United States)

    Brito Díaz, Buenaventura; Alemán Sánchez, José Juan; Cabrera de León, Antonio

    2014-07-07

    Heart rate reflects autonomic nervous system activity. Numerous studies have demonstrated that an increased heart rate at rest is associated with cardiovascular morbidity and mortality as an independent risk factor. It has been shown a link between cardiac autonomic balance and inflammation. Thus, an elevated heart rate produces a micro-inflammatory response and is involved in the pathogenesis of endothelial dysfunction. In turn, decrease in heart rate produces benefits in congestive heart failure, myocardial infarction, atrial fibrillation, obesity, hyperinsulinemia, insulin resistance, and atherosclerosis. Alteration of other heart rate-related parameters, such as their variability and recovery after exercise, is associated with risk of cardiovascular events. Drugs reducing the heart rate (beta-blockers, calcium antagonists and inhibitors of If channels) have the potential to reduce cardiovascular events. Although not recommended in healthy subjects, interventions for reducing heart rate constitute a reasonable therapeutic goal in certain pathologies. Copyright © 2013 Elsevier España, S.L. All rights reserved.

  6. Reduced Dietary Sodium Intake Increases Heart Rate

    DEFF Research Database (Denmark)

    Graudal, Niels A; Hubeck-Graudal, Thorbjørn; Jürgens, Gesche

    2016-01-01

    Reduced dietary sodium intake (sodium reduction) increases heart rate in some studies of animals and humans. As heart rate is independently associated with the development of heart failure and increased risk of premature death a potential increase in heart rate could be a harmful side......-effect of sodium reduction. The purpose of the present meta-analysis was to investigate the effect of sodium reduction on heart rate. Relevant studies were retrieved from an updated pool of 176 randomized controlled trials (RCTs) published in the period 1973-2014. Sixty-three of the RCTs including 72 study...... populations reported data on heart rate. In a meta-analysis of these data sodium reduction increased heart rate with 1.65 beats per minute [95% CI: 1.19, 2.11], p heart rate. This effect was independent of baseline blood pressure. In conclusion sodium reduction...

  7. Heart rate in professional musicians

    Directory of Open Access Journals (Sweden)

    García Daniel

    2008-07-01

    Full Text Available Abstract Background Very few studies have analysed heart rate (HR with regard to music playing, and the scarce evidence available is controversial. The purpose of this study was to analyse the HR response of professional musicians during their real-work activity. Methods Sixty-two voluntary professional musicians (20 women, 42 men, whose ages ranged between 15 and 71 years old, underwent the test while playing their instruments in real life scenarios, i.e. rehearsals, practice and public concerts. The musicians carried Sport Tester PE4000 (Polar®, Finland pulsometers to record their HR. In order to compare data from differently aged subjects we calculated their Maximum Theoretical Heart Rate (MTHR. Later on we found out the MTHR percentages (%MTHR corresponding to the registered HR of each subject in different situations. The value of the MTHR for every musician was obtained by means of the 220 – age (in years formula. Results Throughout the HR recordings, we have observed that musicians present a heightened HR while playing (in soloists, mean and maximum HR were 72% and 85%MTHR, respectively. Cardiac demand is significantly higher in concerts than in rehearsals while performing the same musical piece. The HR curves corresponding to the same musician playing in repeated concerts (with the same programme were similar. Conclusion The cardiac demand of a professional instrument player is higher than previously described, much greater than what would be expected from a supposedly sedentary activity.

  8. Heart rate in professional musicians.

    Science.gov (United States)

    Iñesta, Claudia; Terrados, Nicolás; García, Daniel; Pérez, José A

    2008-07-25

    Very few studies have analysed heart rate (HR) with regard to music playing, and the scarce evidence available is controversial. The purpose of this study was to analyse the HR response of professional musicians during their real-work activity. Sixty-two voluntary professional musicians (20 women, 42 men), whose ages ranged between 15 and 71 years old, underwent the test while playing their instruments in real life scenarios, i.e. rehearsals, practice and public concerts. The musicians carried Sport Tester PE4000 (Polar(R), Finland) pulsometers to record their HR.In order to compare data from differently aged subjects we calculated their Maximum Theoretical Heart Rate (MTHR). Later on we found out the MTHR percentages (%MTHR) corresponding to the registered HR of each subject in different situations. The value of the MTHR for every musician was obtained by means of the 220 - age (in years) formula. Throughout the HR recordings, we have observed that musicians present a heightened HR while playing (in soloists, mean and maximum HR were 72% and 85%MTHR, respectively). Cardiac demand is significantly higher in concerts than in rehearsals while performing the same musical piece. The HR curves corresponding to the same musician playing in repeated concerts (with the same programme) were similar. The cardiac demand of a professional instrument player is higher than previously described, much greater than what would be expected from a supposedly sedentary activity.

  9. Benchmarking heart rate variability toolboxes.

    Science.gov (United States)

    Vest, Adriana N; Li, Qiao; Liu, Chengyu; Nemati, Shamim; Shah, Amit; Clifford, Gari D

    Heart rate variability (HRV) metrics hold promise as potential indicators for autonomic function, prediction of adverse cardiovascular outcomes, psychophysiological status, and general wellness. Although the investigation of HRV has been prevalent for several decades, the methods used for preprocessing, windowing, and choosing appropriate parameters lack consensus among academic and clinical investigators. A comprehensive and open-source modular program is presented for calculating HRV implemented in Matlab with evidence-based algorithms and output formats. We compare our software with another widely used HRV toolbox written in C and available through PhysioNet.org. Our findings show substantially similar results when using high quality electrocardiograms (ECG) free from arrhythmias. Our software shows equivalent performance alongside an established predecessor and includes validated tools for performing preprocessing, signal quality, and arrhythmia detection to help provide standardization and repeatability in the field, leading to fewer errors in the presence of noise or arrhythmias. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Heart rate and heart rate variability in normal young adults.

    Science.gov (United States)

    Coumel, P; Maison-Blanche, P; Catuli, D

    1994-11-01

    The relationships between heart rate (HR) and HR variability (HRV) are not simple. Because both depend on the autonomic nervous system (ANS), they are not independent variables. Technically, the quantification of HRV is influenced by the duration of the cardiac cycles. The complexity of these relationships does not justify ignoring HR when studying HRV, as frequently occurs. Using spectral and nonspectral methods, the HR and various normalized and non-normalized indices of HRV were studied in 24-hour recordings of a homogeneous cohort of seventeen 20-year-old healthy males. The HR-HRV relationships were appraised by analyzing the same data in two different ways. The 24 mean hourly values provide consistent information on the circadian behavior of the indices, while the average 24-hour individual data show a wide spectrum of normality. Combined approaches allow assessment of the direct impact of RR interval on HRV evaluation. The correlations between HR and normalized indices of HRV are weaker in 24-hour individual data than in pooled hourly data of the same individuals. These correlations are close to 1 in the latter case, which does not mean that measuring HRV is simply another method of evaluating HR, but that normal physiology supposes a harmonious behavior of the various indices. When considered individually without normalization, the specific indices of vagal modulation (high-frequency band of the spectrum, short-term HR oscillations of the nonspectral analysis) consistently increase at night and diminish during the day. However, the low-frequency power, which supposedly reflects sympathetic influences, also increases at night, whereas more logically the longer HR oscillations would predominate during the day. Moreover, the selective analysis of HR oscillations during HR acceleration or decrease indicates that their behavior differs accordingly. We recommend that closer attention be paid to the complex relationships between HR and HRV. The strong correlations

  11. Resting heart rate, heart rate variability and functional decline in old age

    DEFF Research Database (Denmark)

    Ogliari, Giulia; Mahinrad, Simin; Stott, David J

    2015-01-01

    BACKGROUND: Heart rate and heart rate variability, markers of cardiac autonomic function, have been linked with cardiovascular disease. We investigated whether heart rate and heart rate variability are associated with functional status in older adults, independent of cardiovascular disease. METHODS......: We obtained data from the Prospective Study of Pravastatin in the Elderly at Risk (PROSPER). A total of 5042 participants were included in the present study, and mean followup was 3.2 years. Heart rate and heart rate variability were derived from baseline 10-second electrocardiograms. Heart rate.......3 years. At baseline, higher heart rate was associated with worse ADL and IADL, and lower SDNN was related to worse IADL (all p values heart rate (range 71-117 beats/min) had a 1.79-fold (95% confidence interval [CI] 1.45-2.22) and 1.35-fold (95% CI 1...

  12. Heart rate reduction and longevity in mice.

    Science.gov (United States)

    Gent, Sabine; Kleinbongard, Petra; Dammann, Philip; Neuhäuser, Markus; Heusch, Gerd

    2015-03-01

    Heart rate correlates inversely with life span across all species, including humans. In patients with cardiovascular disease, higher heart rate is associated with increased mortality, and such patients benefit from pharmacological heart rate reduction. However, cause-and-effect relationships between heart rate and longevity, notably in healthy individuals, are not established. We therefore prospectively studied the effects of a life-long pharmacological heart rate reduction on longevity in mice. We hypothesized, that the total number of cardiac cycles is constant, and that a 15% heart rate reduction might translate into a 15% increase in life span. C57BL6/J mice received either placebo or ivabradine at a dose of 50 mg/kg/day in drinking water from 12 weeks to death. Heart rate and body weight were monitored. Autopsy was performed on all non-autolytic cadavers, and parenchymal organs were evaluated macroscopically. Ivabradine reduced heart rate by 14% (median, interquartile range 12-15%) throughout life, and median life span was increased by 6.2% (p = 0.01). Body weight and macroscopic findings were not different between placebo and ivabradine. Life span was not increased to the same extent as heart rate was reduced, but nevertheless significantly prolonged by 6.2%.

  13. Heart rate dependency of JT interval sections.

    Science.gov (United States)

    Hnatkova, Katerina; Johannesen, Lars; Vicente, Jose; Malik, Marek

    2017-08-09

    Little experience exists with the heart rate correction of J-Tpeak and Tpeak-Tend intervals. In a population of 176 female and 176 male healthy subjects aged 32.3±9.8 and 33.1±8.4years, respectively, curve-linear and linear relationship to heart rate was investigated for different sections of the JT interval defined by the proportions of the area under the vector magnitude of the reconstructed 3D vectorcardiographic loop. The duration of the JT sub-section between approximately just before the T peak and almost the T end was found heart rate independent. Most of the JT heart rate dependency relates to the beginning of the interval. The duration of the terminal T wave tail is only weakly heart rate dependent. The Tpeak-Tend is only minimally heart rate dependent and in studies not showing substantial heart rate changes does not need to be heart rate corrected. For any correction formula that has linear additive properties, heart rate correction of JT and JTpeak intervals is practically the same as of the QT interval. However, this does not apply to the formulas in the form of Int/RR(a) since they do not have linear additive properties. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Losartan improves heart rate variability and heart rate turbulence in heart failure due to ischemic cardiomyopathy.

    Science.gov (United States)

    Ozdemir, Murat; Arslan, Uğur; Türkoğlu, Sedat; Balcioğlu, Serhat; Cengel, Atiye

    2007-12-01

    Heart rate variability (HRV) and heart rate turbulence are known to be disturbed and associated with excess mortality in heart failure. The aim of this study was to investigate whether losartan, when added on top of beta-blocker and angiotensin-converting enzyme inhibitor (ACEI) therapy, could improve these indices in patients with systolic heart failure. Seventy-seven patients (mean age 60.4 +/- 8.0, 80.5% male) with ischemic cardiomyopathy (mean ejection fraction 34.5 +/- 4.4%) and New York Heart Association Class II-III heart failure symptoms, already receiving a beta-blocker and an ACEI, were randomly assigned to either open-label losartan (losartan group) or no additional drug (control group) in a 2:1 ratio and the patients were followed for 12 weeks. The HRV and heart rate turbulence indices were calculated from 24-hour Holter recordings both at the beginning and at the end of follow-up. The baseline clinical characteristics, HRV, and heart rate turbulence indices were similar in the 2 groups. At 12 weeks of follow-up, all HRV parameters except pNN50 increased (SDNN: 113.2 +/- 34.2 versus 127.8 +/- 24.1, P = .001; SDANN: 101.5 +/- 31.7 versus 115.2 +/- 22.0, P = .001; triangular index: 29.9 +/- 11.1 versus 34.2 +/- 7.9, P = .008; RMSSD: 29.1 +/- 20.2 versus 34.3 +/- 23.0, P = .009; NN50: 5015.3 +/- 5554.9 versus 6446.7 +/- 6101.1, P = .024; NN50: 5.65 +/- 6.41 versus 7.24 +/- 6.99, P = .089; SDNNi: 45.1 +/- 13.3 versus 50.3 +/- 14.5, P = .004), turbulence onset decreased (-0. 61 +/- 1.70 versus -1.24 +/- 1.31, P = .003) and turbulence slope increased (4.107 +/- 3.881 versus 5.940 +/- 4.281, P = .004) significantly in the losartan group as compared with controls. A 12-week-long losartan therapy significantly improved HRV and heart rate turbulence in patients with Class II-III heart failure and ischemic cardiomyopathy already on beta-blockers and ACEI.

  15. Mental load, heart rate and heart rate variability.

    NARCIS (Netherlands)

    Blitz, P.S.; Hoogstraten, J.; Mulder, G.

    1970-01-01

    "Several investigators have shown that diminished sinus arrhythmia can be seen as an indication of increased mental load. The present experiment deals with the influence of different levels of mental load, operationalized as the number of binary choices per minute, on the regularity of the heart

  16. Measuring heart rate with optical sensor

    NARCIS (Netherlands)

    Barachi, M. (Mitra)

    2014-01-01

    The problem addressed in this report is to verify the possibility of using an optical sensor in the SaxShirt in order to extract the heart rate. There are specifically three questions that we try to address. 1) How is it possible to extract heart rate (BPM) from the optical sensor? 2) Is it

  17. Resting heart rate estimation using PIR sensors

    Science.gov (United States)

    Kapu, Hemanth; Saraswat, Kavisha; Ozturk, Yusuf; Cetin, A. Enis

    2017-09-01

    In this paper, we describe a non-invasive and non-contact system of estimating resting heart rate (RHR) using a pyroelectric infrared (PIR) sensor. This infrared system monitors and records the chest motion of a subject using the analog output signal of the PIR sensor. The analog output signal represents the composite motion due to inhale-exhale process with magnitude much larger than the minute vibrations of heartbeat. Since the acceleration of the heart activity is much faster than breathing the second derivative of the PIR sensor signal monitoring the chest of the subject is used to estimate the resting heart rate. Experimental results indicate that this ambient sensor can measure resting heart rate with a chi-square significance level of α = 0.05 compared to an industry standard PPG sensor. This new system provides a low cost and an effective way to estimate the resting heart rate, which is an important biological marker.

  18. Heart rate and respiratory rate influence on heart rate variability repeatability: effects of the correction for the prevailing heart rate

    Directory of Open Access Journals (Sweden)

    Jakub Sławomir Gąsior

    2016-08-01

    Full Text Available Background: Since heart rate variability (HRV is associated with average heart rate (HR and respiratory rate (RespRate, alterations in these parameters may impose changes in HRV. Hence the repeatability of HRV measurements may be affected by differences in HR and RespRate. The study aimed to evaluate HRV repeatability and its association with changes in HR and RespRate.Methods: Forty healthy volunteers underwent two ECG examinations seven days apart. Standard HRV indices were calculated from 5-min ECG recordings. The ECG-derived respiration signal was estimated to assess RespRate. To investigate HR impact on HRV, HRV parameters were corrected for prevailing HR. Results: Differences in HRV parameters between the measurements were associated with the changes in HR and RespRate. However, in multiple regression analysis only HR alteration proved to be independent determinant of the HRV differences – every change in HR by 1 bpm changed HRV values by 16.5% on average. After overall removal of HR impact on HRV, coefficients of variation of the HRV parameters significantly dropped on average by 26.8% (p < 0.001, i.e. by the same extent HRV reproducibility improved. Additionally, the HRV correction for HR decreased association between RespRate and HRV. Conclusions: In stable conditions, HR but not RespRate is the most powerful factor determining HRV reproducibility and even a minimal change of HR may considerably alter HRV. However, the removal of HR impact may significantly improve HRV repeatability. The association between HRV and RespRate seems to be, at least in part, HR dependent.

  19. Peak heart rates at extreme altitudes

    DEFF Research Database (Denmark)

    Lundby, C; Van Hall, Gerrit

    2001-01-01

    We have measured maximal heart rate during a graded maximal bicycle exercise test to exhaustion in five healthy climbers before and during an expedition to Mt. Everest. Maximal heart rates at sea level were 186 (177-204) beats/min(-1) at sea level and 170 (169-182) beats/min(-1) with acute hypoxia....... After 1, 4 and 6 weeks of acclimatization to 5400 m, maximal heart rates were 155 (135-182), 158 (144-182), and 155 (140-183) beats/min(-1), respectively. Heart rates of two of the climbers were measured during their attempt to reach the summit of Mt. Everest without the use of supplemental oxygen....... The peak heart rates at 8,750 m for the two climbers were 142 and 144 beats/min(-1), which were similar to their maximal heart rates during exhaustive bicycle exercise at 5,400 m, the values being 144 and 148 beats/min(-1), respectively. The peak heart rates at 8,750 m are in agreement with other field...

  20. FPGA Implementation of Heart Rate Monitoring System.

    Science.gov (United States)

    Panigrahy, D; Rakshit, M; Sahu, P K

    2016-03-01

    This paper describes a field programmable gate array (FPGA) implementation of a system that calculates the heart rate from Electrocardiogram (ECG) signal. After heart rate calculation, tachycardia, bradycardia or normal heart rate can easily be detected. ECG is a diagnosis tool routinely used to access the electrical activities and muscular function of the heart. Heart rate is calculated by detecting the R peaks from the ECG signal. To provide a portable and the continuous heart rate monitoring system for patients using ECG, needs a dedicated hardware. FPGA provides easy testability, allows faster implementation and verification option for implementing a new design. We have proposed a five-stage based methodology by using basic VHDL blocks like addition, multiplication and data conversion (real to the fixed point and vice-versa). Our proposed heart rate calculation (R-peak detection) method has been validated, using 48 first channel ECG records of the MIT-BIH arrhythmia database. It shows an accuracy of 99.84%, the sensitivity of 99.94% and the positive predictive value of 99.89%. Our proposed method outperforms other well-known methods in case of pathological ECG signals and successfully implemented in FPGA.

  1. Heart rate response to hypoxic exercise

    DEFF Research Database (Denmark)

    Lundby, C; Møller, P; Kanstrup, I L

    2001-01-01

    This study examined the effects of dopamine D(2)-receptor blockade on the early decrease in maximal heart rate at high altitude (4559 m). We also attempted to clarify the time-dependent component of this reduction and the extent to which it is reversed by oxygen breathing. Twelve subjects performed...... progressively decreased the maximal heart rate from day 1 and onwards; also, hypoxia by itself increased plasma noradrenaline levels after maximal exercise. Domperidone further increased maximal noradrenaline concentrations, but had no effect on maximal heart rate. On each study day at altitude, oxygen...... breathing completely reversed the decrease in maximal heart rate to values not different from those at sea level. In conclusion, dopamine D(2)-receptor blockade with domperidone demonstrates that hypoxic exercise in humans activates D(2)-receptors, resulting in a decrease in circulating levels...

  2. Heart rate and heart rate variability in dogs with different degrees of myxomatous mitral valve disease

    DEFF Research Database (Denmark)

    Rasmussen, Caroline Elisabeth; Falk, Bo Torkel; Zois, Nora Elisabeth

    2011-01-01

    HEART RATE AND HEART RATE VARIABILITY IN DOGS WITH DIFFERENT DEGREES OF MYXOMATOUS MITRAL VALVE DISEASE. CE Rasmussen1, T Falk1, NE Zois1, SG Moesgaard1, HD Pedersen2, J Häggström3 and LH Olsen1. 1. Department of Basic Animal and Veterinary Sciences, Faculty of Life Sciences, University of Copenh......HEART RATE AND HEART RATE VARIABILITY IN DOGS WITH DIFFERENT DEGREES OF MYXOMATOUS MITRAL VALVE DISEASE. CE Rasmussen1, T Falk1, NE Zois1, SG Moesgaard1, HD Pedersen2, J Häggström3 and LH Olsen1. 1. Department of Basic Animal and Veterinary Sciences, Faculty of Life Sciences, University...

  3. Heart rate monitors and abnormal heart rhythm detection.

    Science.gov (United States)

    Boudet, G; Chamoux, A

    2000-10-01

    We test the accuracy of two third generation heart rate monitors (HRM), Accurex Plus and Vantage NV and compare these data with those of an older monitor, PE 4000. Then we investigate responses of the HRM's to abnormal heart rhythms (HR). Accurex Plus and Vantage NV, and PE 4000 were tested in the laboratory under both stable and transient conditions. The Phantom 320 HR simulator gave 7 stable heart rates, each lasting 3 min. The responses of the HRM's to abnormal heart rhythms were tested with an automatic arrhythmia program lasting 17 min. The new HRM's, Accurex Plus and Vantage NV, were more accurate (89 to 94% and over 98% at +/-3 beats per min) in the stable state than the PE 4000. They all showed a smoothing effect in transient measurements, which was stronger in decelerating HR (1st case) than in accelerating HR (2nd case). - 1st case: Accurex Plus =Vantage NV >PE 4000 -2nd case: PE 4000 >Accurex =Vantage. Most isolated heart rhythm disorders (missing beat, pause 4 s, important bradycardia or tachycardia.

  4. Hierarchical Structure of Heart Rate Variability in Humans

    Science.gov (United States)

    Gao, X. Z.; Ching, E. S. C.; Lin, D. C.

    2004-03-01

    We show a hierarchical structure (HS) of the She-Leveque form in the beat-to-beat RR intervals of heart rate variability (HRV) in humans. This structure, first found as an empirical law in turbulent fluid flows, implies further details in the HRV multifractal scaling. We tested HS using daytime RRi data from healthy subjects and heart diseased patients with congestive heart failure and found a universal law C(b) where b characterizes the multifractality of HRV and C is related to a co-dimension parameter of the most violent events in the fluctuation. The potential of diagnosis is discussed based on the characteristics of this finding. To model the HRV phenomenology, we propose a local-feedback-global-cascade (LFGC) model based on the She-Waymire (SW) cascade solution to the HS in fluid turbulence. This model extends from the previous work in that it integrates additive law multiplicatively into the cascade structure. It is an attempt to relate to the cardiovascular physiology which consists of numerous feedback controls that function primarily on the principle of additive law. In particular, the model is based on the same philosophy as the SW cascade that its multifractal dynamics consists of a singular and a modulating component. In the LFGC model, we introduce local feedback to model the dynamics of the modulating effect. The novelty of our model is to incorporate the cascade structure in the scheduling for the feedback control. This model also represents an alternative solution to the HS. We will present the simulation results by the LFGC model and discuss its implication in physiology terms.

  5. Effects of visual feedback on manipulation performance and patient ratings.

    Science.gov (United States)

    Triano, John J; Scaringe, John; Bougie, Jacqueline; Rogers, Carolyn

    2006-06-01

    This study examined the explicit targeted outcome (a criterion standard) and visual feedback on the immediate change in and the short-term retention of performance by novice operators for a high-velocity, low-amplitude procedure under realistic conditions. This study used a single-blind randomized experimental design. Forty healthy male (n = 26) and female (n = 14) chiropractic student volunteers with no formal training in spinal manipulative therapy participated. Biomechanical parameters of an L4 mammillary push spinal manipulation procedure performed by novice operators were quantified. Participants were randomly assigned to 2 groups and paired. One group received visual feedback from load-time histories of their performance compared with a criterion standard before a repeat performance. Participants then performed a 10-minute distractive exercise consisting of National Board of Chiropractic Examiners review questions. The second group received no feedback. An independent rating of performance was conducted for each participant by his/her partner. Results were analyzed separately for biomechanical parameters for partner ratings using the Student t test with levels of significance (P visual feedback was associated with change in the biomechanical performance of group 2, a minimum of 14% and a maximum of 32%. Statistical analysis rating of the performance favored the feedback group on 4 of the parameters (fast, P < .0008; force, P < .0056; precision, P < .0034; and composite, P < .0016). Quantitative feedback, based on a tangible conceptualization of the target performance, resulted in immediate and significant improvement in all measured parameters. Newly developed skills were retained at least over short intervals even after distractive tasks. Learning what to do with feedback on one's own performance may be more important than the classic teaching of how to do it.

  6. Heart Rate Variability - A Historical Perspective

    Directory of Open Access Journals (Sweden)

    George E Billman

    2011-11-01

    Full Text Available 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 heart rate variability. 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 1960’s, 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 heart rate variability.

  7. Heart rate variability biofeedback: how and why does it work?

    Science.gov (United States)

    Lehrer, Paul M; Gevirtz, Richard

    2014-01-01

    In recent years there has been substantial support for heart rate variability biofeedback (HRVB) as a treatment for a variety of disorders and for performance enhancement (Gevirtz, 2013). Since conditions as widely varied as asthma and depression seem to respond to this form of cardiorespiratory feedback training, the issue of possible mechanisms becomes more salient. The most supported possible mechanism is the strengthening of homeostasis in the baroreceptor (Vaschillo et al., 2002; Lehrer et al., 2003). Recently, the effect on the vagal afferent pathway to the frontal cortical areas has been proposed. In this article, we review these and other possible mechanisms that might explain the positive effects of HRVB.

  8. Heart rate variability biofeedback: How and why does it work?

    Directory of Open Access Journals (Sweden)

    Paul M Lehrer

    2014-07-01

    Full Text Available In recent years there has been substantial support for Heart Rate Variability Biofeedback (HRVB as a treatment for a variety of disorders and for performance enhancement (Gevirtz, 2013. Since conditions as widely varied as asthma and depression seem to respond to this form of cardiorespiratory feedback training, the issue of possible mechanisms becomes more salient. The most supported possible mechanism is the strengthening of homeostasis in the barorecptor (Vashillo, et al, 2002; Lehrer, et al, 2003. Recently, the effect on the vagal afferent pathway to the frontal cortical areas has been proposed. In this article, we review these and other possible mechanisms that might explain the positive effects of HRVB.

  9. Resting Heart Rate and Auditory Evoked Potential

    Directory of Open Access Journals (Sweden)

    Simone Fiuza Regaçone

    2015-01-01

    Full Text Available The objective of this study was to evaluate the association between rest heart rate (HR and the components of the auditory evoked-related potentials (ERPs at rest in women. We investigated 21 healthy female university students between 18 and 24 years old. We performed complete audiological evaluation and measurement of heart rate for 10 minutes at rest (heart rate monitor Polar RS800CX and performed ERPs analysis (discrepancy in frequency and duration. There was a moderate negative correlation of the N1 and P3a with rest HR and a strong positive correlation of the P2 and N2 components with rest HR. Larger components of the ERP are associated with higher rest HR.

  10. Low Resting Heart Rate and Stalking Perpetration.

    Science.gov (United States)

    Boisvert, Danielle; Wells, Jessica; Armstrong, Todd; Lewis, Richard H; Woeckener, Matthias; Nobles, Matt R

    2017-04-01

    There is consistent evidence to suggest that individuals with low resting heart rate are more likely to engage in a variety of antisocial behaviors. The present study examines whether this finding can be extended to stalking perpetration. Drawing from fearlessness theory and stimulation-seeking theory, as well as conceptual work of Meloy and Fisher, we find that individuals with low resting heart rates had significantly greater odds of engaging in stalking behavior, net of controls for sex, age, race, self-control, parental affection, delinquent peers, attitudes/beliefs toward crime, and aggression. When disaggregated by sex, the heart rate-stalking relationship was found to be significant for males, but not for females. The implications of these findings are discussed from a biosocial perspective.

  11. Improved ultrasound transducer positioning by fetal heart location estimation during Doppler based heart rate measurements.

    Science.gov (United States)

    Hamelmann, Paul; Vullings, Rik; Schmitt, Lars; Kolen, Alexander F; Mischi, Massimo; van Laar, Judith O E H; Bergmans, Jan W M

    2017-09-21

    Doppler ultrasound (US) is the most commonly applied method to measure the fetal heart rate (fHR). When the fetal heart is not properly located within the ultrasonic beam, fHR measurements often fail. As a consequence, clinical staff need to reposition the US transducer on the maternal abdomen, which can be a time consuming and tedious task. In this article, a method is presented to aid clinicians with the positioning of the US transducer to produce robust fHR measurements. A maximum likelihood estimation (MLE) algorithm is developed, which provides information on fetal heart location using the power of the Doppler signals received in the individual elements of a standard US transducer for fHR recordings. The performance of the algorithm is evaluated with simulations and in vitro experiments performed on a beating-heart setup. Both the experiments and the simulations show that the heart location can be accurately determined with an error of less than 7 mm within the measurement volume of the employed US transducer. The results show that the developed algorithm can be used to provide accurate feedback on fetal heart location for improved positioning of the US transducer, which may lead to improved measurements of the fHR.

  12. Effects of social stress on heart rate and heart rate variability in growing pigs

    NARCIS (Netherlands)

    de Jong, IC; Sgoifo, A; Lambooij, E; Korte, SM; Blokhuis, HJ; Koolhaas, JM

    The effects of social stress on heart rate, heart rate variability and the occurrence of cardiac arrhythmias were studied in 12 growing pigs. Social stress was induced during a good competition test with a pen mate, and subsequently during a resident-intruder test with an unacquainted pig in which

  13. Effects of social stress on heart rate and heart rate variability in growing pigs

    NARCIS (Netherlands)

    Jong, de I.C.; Sgoifo, A.; Lambooij, E.; Korte, S.M.; Blokhuis, H.J.; Koolhaas, J.M.

    2000-01-01

    The effects of social stress on heart rate, heart rate variability and the occurrence of cardiac arrhythmias were studied in 12 growing pigs. Social stress was induced during a good competition test with a pen mate, and subsequently during a resident-intruder test with an unacquainted pig in which

  14. Heart rate control via vagus nerve stimulation

    NARCIS (Netherlands)

    Buschman, H.P.J.; Storm, Corstiaan J.; Duncker, Dirk J.; Verdouw, Pieter D.; van der Aa, Hans E.; van der Kemp, Peter

    2006-01-01

    Objectives: There is ample and well-established evidence that direct electrical stimulation of the vagus nerve can change heart rate in animals and humans. Since tachyarrhythmias cannot always be controlled through medication, we sought, in this pilot study, to elucidate whether a clinical

  15. Heart Rate Fragmentation: A Symbolic Dynamical Approach

    Directory of Open Access Journals (Sweden)

    Madalena D. Costa

    2017-11-01

    Full Text Available Background: We recently introduced the concept of heart rate fragmentation along with a set of metrics for its quantification. The term was coined to refer to an increase in the percentage of changes in heart rate acceleration sign, a dynamical marker of a type of anomalous variability. The effort was motivated by the observation that fragmentation, which is consistent with the breakdown of the neuroautonomic-electrophysiologic control system of the sino-atrial node, could confound traditional short-term analysis of heart rate variability.Objective: The objectives of this study were to: (1 introduce a symbolic dynamical approach to the problem of quantifying heart rate fragmentation; (2 evaluate how the distribution of the different dynamical patterns (“words” varied with the participants' age in a group of healthy subjects and patients with coronary artery disease (CAD; and (3 quantify the differences in the fragmentation patterns between the two sample populations.Methods: The symbolic dynamical method employed here was based on a ternary map of the increment NN interval time series and on the analysis of the relative frequency of symbolic sequences (words with a pre-defined set of features. We analyzed annotated, open-access Holter databases of healthy subjects and patients with CAD, provided by the University of Rochester Telemetric and Holter ECG Warehouse (THEW.Results: The degree of fragmentation was significantly higher in older individuals than in their younger counterparts. However, the fragmentation patterns were different in the two sample populations. In healthy subjects, older age was significantly associated with a higher percentage of transitions from acceleration/deceleration to zero acceleration and vice versa (termed “soft” inflection points. In patients with CAD, older age was also significantly associated with higher percentages of frank reversals in heart rate acceleration (transitions from acceleration to

  16. Heart Rate Fragmentation: A Symbolic Dynamical Approach.

    Science.gov (United States)

    Costa, Madalena D; Davis, Roger B; Goldberger, Ary L

    2017-01-01

    Background: We recently introduced the concept of heart rate fragmentation along with a set of metrics for its quantification. The term was coined to refer to an increase in the percentage of changes in heart rate acceleration sign, a dynamical marker of a type of anomalous variability. The effort was motivated by the observation that fragmentation, which is consistent with the breakdown of the neuroautonomic-electrophysiologic control system of the sino-atrial node, could confound traditional short-term analysis of heart rate variability. Objective: The objectives of this study were to: (1) introduce a symbolic dynamical approach to the problem of quantifying heart rate fragmentation; (2) evaluate how the distribution of the different dynamical patterns ("words") varied with the participants' age in a group of healthy subjects and patients with coronary artery disease (CAD); and (3) quantify the differences in the fragmentation patterns between the two sample populations. Methods: The symbolic dynamical method employed here was based on a ternary map of the increment NN interval time series and on the analysis of the relative frequency of symbolic sequences (words) with a pre-defined set of features. We analyzed annotated, open-access Holter databases of healthy subjects and patients with CAD, provided by the University of Rochester Telemetric and Holter ECG Warehouse (THEW). Results: The degree of fragmentation was significantly higher in older individuals than in their younger counterparts. However, the fragmentation patterns were different in the two sample populations. In healthy subjects, older age was significantly associated with a higher percentage of transitions from acceleration/deceleration to zero acceleration and vice versa (termed "soft" inflection points). In patients with CAD, older age was also significantly associated with higher percentages of frank reversals in heart rate acceleration (transitions from acceleration to deceleration and vice

  17. Median maximal heart rate for heart rate calibration in different conditions: laboratory, field and competition.

    Science.gov (United States)

    Boudet, G; Garet, M; Bedu, M; Albuisson, E; Chamoux, A

    2002-05-01

    The objective of this study was to evaluate the variability of maximal heart rate in three different conditions: laboratory tests, field tests, and competitions. Sixteen male endurance volunteers were tested in five exhaustive tests for each condition. All exhaustive events were heart rate monitored (Accurex plus, Polar Electro, Finland) and true maximal heart rates were assessed and compared with each other and with predicted maximal heart rates. Results show that under the three conditions HR(peaks) were not statistically different (p = 0.62, NS, Friedman test). Mean HR(peaks) (SD) were: laboratory = 194.3 (7.8), field = 193.8 (11.8), competition = 192.3 (10.1) beats x min(-1). Conditions for reaching individual heart rate peak were in the laboratory (treadmill VO(2)max protocol) for 5 subjects, in field tests for 7 subjects and in competitions for 6 subjects (two circumstances for two subjects). A large intra-individual variation existed in the three circumstances (+/- 6 beats x min(-1)). Absolute median maximal heart rate was 190.0 bpm (9.32) i.e 7.6 bpm lower than heart rate peak. Both were highly related (rho = 0.89, z = 3.449, p = 0.0006, Spearman test). Median maximal heart rates inter-condition relationship were higher. Median maximal heart rate was more stable and took more information into account than an isolated peak. It gives a central value that minimizes the potential risk of under or over estimation when calibrating exercise intensities with HR.

  18. Gaussian mixture model of heart rate variability.

    Directory of Open Access Journals (Sweden)

    Tommaso Costa

    Full Text Available Heart rate variability (HRV is an important measure of sympathetic and parasympathetic functions of the autonomic nervous system and a key indicator of cardiovascular condition. This paper proposes a novel method to investigate HRV, namely by modelling it as a linear combination of Gaussians. Results show that three Gaussians are enough to describe the stationary statistics of heart variability and to provide a straightforward interpretation of the HRV power spectrum. Comparisons have been made also with synthetic data generated from different physiologically based models showing the plausibility of the Gaussian mixture parameters.

  19. Heart rate detection from plantar bioimpedance measurements.

    Science.gov (United States)

    González Landaeta, R; Casas, O; Pallàs-Areny, R

    2006-01-01

    The heart rate is a basic health indicator, useful in both clinical measurements and home health care. Current home care systems often require the attachment of electrodes or other sensors to the body, which can be cumbersome to the patient. Moreover, some measurements are sensitive to movement artifacts, are not user-friendly and require a specialized supervision. In this paper, a novel technique for heart rate measurement for a standing subject is proposed, which is based on plantar bioimpedance measurements, such as those performed by some bathroom weighting scales for body composition analysis. Because of the low level of heart-related impedance variations, the measurement system has a gain of 1400. We have implemented a fully differential AC amplifier with a common-mode rejection ratio (CMRR) of 105 dB at 10 kHz. Coherent demodulation based on synchronous sampling yields a signal-to-noise ratio (SNR) of 55 dB. The system has a sensitivity of 1.9 V/Omega. The technique has been demonstrated on 18 volunteers, whose bioimpedance signal and ECG were simultaneously measured to validate the results. The average cross-correlation coefficient between the heart rates determined from these two signals was 0.998 (std. dev. 0.001).

  20. Music determines heart rate variability of singers

    Directory of Open Access Journals (Sweden)

    Björn eVickhoff

    2013-07-01

    Full Text Available Choir singing is known to promote wellbeing. One reason for this may be that singing demands a slower than normal respiration which may in turn affect heart activity. Coupling of heart rate variability (HRV to respiration is called Respiratory sinus arrhythmia (RSA. This coupling has a subjective as well as a biologically soothing effect, and it is beneficial for cardiovascular function. RSA is seen to be more marked during slow-paced breathing and at lower respiration rates (0.1 Hz and below. In this study, we investigate how singing, which is a form of guided breathing, affects HRV and RSA. The study comprises a group of healthy 18 year olds of mixed gender. The subjects are asked to; (1 hum a single tone and breathe whenever they need to; (2 sing a hymn with free, unguided breathing; and (3 sing a slow mantra and breathe solely between phrases. Heart rate (HR is measured continuously during the study. The study design makes it possible to compare above three levels of song structure. In a separate case study, we examine five individuals performing singing tasks (1-(3. We collect data with more advanced equipment, simultaneously recording HR, respiration, skin conductance and finger temperature. We show how song structure, respiration and heart rate are connected. Unison singing of regular song structures makes the hearts of the singers accelerate and decelerate simultaneously. Implications concerning the effect on wellbeing and health are discussed as well as the question how this inner entrainment may affect perception and behavior.

  1. Lessons from the Heart: Individualizing Physical Education with Heart Rate Monitors.

    Science.gov (United States)

    Kirkpatrick, Beth; Birnbaum, Burton H.

    Learning about the relationship between heart rate and physical activity is an important aspect of fitness education. Use of a heart rate monitor (HRM) helps a student to understand how stretching and large muscle movements gradually increase the heart rate and blood flow, and enables students to measure their exercise heart rates and set goals…

  2. Changes in heart rate variability with age.

    Science.gov (United States)

    Reardon, M; Malik, M

    1996-11-01

    Depressed heart rate variability (HRV) after a myocardial infarction is associated with increased mortality. This is thought to be due to reduced parasympathetic activity and heightened sympathetic activity. Aging is associated with depressed HRV, but little is known of the affect of aging on parasympathetic activity. This study examined 56 healthy subjects (age range 40-102 years; 39 women). None had a history of heart disease or were on medication that would affect cardiac function. All had normal resting ECGs, normal heart size on chest X ray, and normal electrolytes. In all subjects, 24-hour Holter recordings were performed and used to measure HRV. In particular, the study examined the affect of age on HRV triangular index, which gives an estimate of overall HRV, and on RMSSD (square root of the mean squared differences of successive normal-to-normal RR intervals), which gives an estimate of short-term components of HRV and is thought to reflect the overall extent of vagal modulations of heart rates. Both these parameters were compared in patients younger and older than 70 years. Each recording lasted at least 17 hours; the majority of recordings were longer than 20 hours. There was a significant decrease in HRV triangular index with age (r = -0.4, P 70 years compared with those < 70 years (38.0 +/- 9.3 vs 31.0 +/- 11, respectively, P < 0.02). There was no significant difference in RMSSD between the two age groups (26.7 +/- 8.2 ms vs 28.4 +/- 11.3 ms, respectively, P = NS). Thus, the study concludes that aging reduces the global measure of HRV and may reflect reduced responsiveness of autonomic activity to external environmental stimuli with age. However, the time-domain short-term components of HRV are not affected by age and, therefore, the fast and presumably vagal modulations of heart rate appear to be maintained.

  3. Sound and vibration : effects on infants' heart rate and heart rate variability during neonatal transport

    OpenAIRE

    Karlsson, Björn-Markus; Lindkvist, Marie; Lindkvist, Markus; Karlsson, Marcus; Lundström, Ronnie; Håkansson, Stellan; Wiklund, Urban; van den Berg, Johannes

    2012-01-01

    Aim: To measure the effect of sound and whole-body vibration on infants' heart rate and heart rate variability during ground and air ambulance transport. Methods: Sixteen infants were transported by air ambulance with ground ambulance transport to and from the airports. Whole-body vibration and sound levels were recorded and heart parameters were obtained by ECG signal. Results: Sound and whole-body vibration levels exceeded the recommended limits. Mean whole-body vibration and sound levels w...

  4. [Music and heart rate variability. Study of the effect of music on heart rate variability in healthy adolescents].

    Science.gov (United States)

    Escher, J; Evéquoz, D

    1999-05-20

    The effect of trophotropic (relaxing) music on heart rate and heart rate variability has been investigated in 23 healthy young individuals by means of 24-hour Holter-ECG. Relaxing music (Bach, Vivaldi, Mozart) resulted in significant reduction of heart rate and also significant reduction of heart rate variability. The significance of these results for the use of music in coronary heart disease is discussed.

  5. Bluetooth Heart Rate Monitors For Spaceflight

    Science.gov (United States)

    Buxton, R. E.; West, M. R.; Kalogera, K. L.; Hanson, A. M.

    2016-01-01

    Heart rate monitoring is required for crewmembers during exercise aboard the International Space Station (ISS) and will be for future exploration missions. The cardiovascular system must be sufficiently stressed throughout a mission to maintain the ability to perform nominal and contingency/emergency tasks. High quality heart rate data are required to accurately determine the intensity of exercise performed by the crewmembers and show maintenance of VO2max. The quality of the data collected on ISS is subject to multiple limitations and is insufficient to meet current requirements. PURPOSE: To evaluate the performance of commercially available Bluetooth heart rate monitors (BT_HRM) and their ability to provide high quality heart rate data to monitor crew health aboard the ISS and during future exploration missions. METHODS: Nineteen subjects completed 30 data collection sessions of various intensities on the treadmill and/or cycle. Subjects wore several BT_HRM technologies for each testing session. One electrode-based chest strap (CS) was worn, while one or more optical sensors (OS) were worn. Subjects were instrumented with a 12-lead ECG to compare the heart rate data from the Bluetooth sensors. Each BT_HRM data set was time matched to the ECG data and a +/-5bpm threshold was applied to the difference between the 2 data sets. Percent error was calculated based on the number of data points outside the threshold and the total number of data points. RESULTS: The electrode-based chest straps performed better than the optical sensors. The best performing CS was CS1 (1.6% error), followed by CS4 (3.3% error), CS3 (6.4% error), and CS2 (9.2% error). The OS resulted in 10.4% error for OS1 and 14.9% error for OS2. CONCLUSIONS: The highest quality data came from CS1, but unfortunately it has been discontinued by the manufacturer. The optical sensors have not been ruled out for use, but more investigation is needed to determine how to obtain the best quality data. CS2 will be

  6. Optically Remote Noncontact Heart Rates Sensing Technique

    Science.gov (United States)

    Thongkongoum, W.; Boonduang, S.; Limsuwan, P.

    2017-09-01

    Heart rate monitoring via optically remote noncontact technique was reported in this research. A green laser (5 mW, 532±10 nm) was projected onto the left carotid artery. The reflected laser light on the screen carried the deviation of the interference patterns. The interference patterns were recorded by the digital camera. The recorded videos of the interference patterns were frame by frame analysed by 2 standard digital image processing (DIP) techniques, block matching (BM) and optical flow (OF) techniques. The region of interest (ROI) pixels within the interference patterns were analysed for periodically changes of the interference patterns due to the heart pumping action. Both results of BM and OF techniques were compared with the reference medical heart rate monitoring device by which a contact measurement using pulse transit technique. The results obtained from BM technique was 74.67 bpm (beats per minute) and OF technique was 75.95 bpm. Those results when compared with the reference value of 75.43±1 bpm, the errors were found to be 1.01% and 0.69%, respectively.

  7. The mitochondrial uniporter controls fight or flight heart rate increases.

    Science.gov (United States)

    Wu, Yuejin; Rasmussen, Tyler P; Koval, Olha M; Joiner, Mei-Ling A; Hall, Duane D; Chen, Biyi; Luczak, Elizabeth D; Wang, Qiongling; Rokita, Adam G; Wehrens, Xander H T; Song, Long-Sheng; Anderson, Mark E

    2015-01-20

    Heart rate increases are a fundamental adaptation to physiological stress, while inappropriate heart rate increases are resistant to current therapies. However, the metabolic mechanisms driving heart rate acceleration in cardiac pacemaker cells remain incompletely understood. The mitochondrial calcium uniporter (MCU) facilitates calcium entry into the mitochondrial matrix to stimulate metabolism. We developed mice with myocardial MCU inhibition by transgenic expression of a dominant-negative (DN) MCU. Here, we show that DN-MCU mice had normal resting heart rates but were incapable of physiological fight or flight heart rate acceleration. We found that MCU function was essential for rapidly increasing mitochondrial calcium in pacemaker cells and that MCU-enhanced oxidative phoshorylation was required to accelerate reloading of an intracellular calcium compartment before each heartbeat. Our findings show that MCU is necessary for complete physiological heart rate acceleration and suggest that MCU inhibition could reduce inappropriate heart rate increases without affecting resting heart rate.

  8. Case Studies in Electronic Fetal Heart Rate Monitoring

    OpenAIRE

    Yee, J.; Parboosingh, I.J.

    1986-01-01

    Subtle changes in the characteristics of the fetal heart rate are currently used to assess the condition of the fetus in late pregnancy and during labour. The authors present three case studies of fetal heart rate monitoring.

  9. BIOPHYSICAL CHARACTERISATION OF THE UNDER-APPRECIATED AND IMPORTANT RELATIONSHIP BETWEEN HEART RATE VARIABILITY AND HEART RATE

    Science.gov (United States)

    Monfredi, Oliver; Lyashkov, Alexey E; Johnsen, Anne-Berit; Inada, Shin; Schneider, Heiko; Wang, Ruoxi; Nirmalan, Mahesh; Wisloff, Ulrik; Maltsev, Victor A; Lakatta, Edward G; Zhang, Henggui; Boyett, Mark R

    2014-01-01

    Heart rate variability (beat-to-beat changes in the RR interval) has attracted considerable attention over the last 30+ years (PubMed currently lists >17,000 publications). Clinically, a decrease in heart rate variability is correlated to higher morbidity and mortality in diverse conditions, from heart disease to foetal distress. It is usually attributed to fluctuation in cardiac autonomic nerve activity. We calculated heart rate variability parameters from a variety of cardiac preparations (including humans, living animals, Langendorff-perfused heart and single sinoatrial nodal cell) in diverse species, combining this with data from previously published papers. We show that regardless of conditions, there is a universal exponential decay-like relationship between heart rate variability and heart rate. Using two biophysical models, we develop a theory for this, and confirm that heart rate variability is primarily dependent on heart rate and cannot be used in any simple way to assess autonomic nerve activity to the heart. We suggest that the correlation between a change in heart rate variability and altered morbidity and mortality is substantially attributable to the concurrent change in heart rate. This calls for re-evaluation of the findings from many papers that have not adjusted properly or at all for heart rate differences when comparing heart rate variability in multiple circumstances. PMID:25225208

  10. Heart Rate During Sleep: Implications for Monitoring Training Status

    OpenAIRE

    Waldeck, Miriam R.; Lambert, Michael I.

    2003-01-01

    Resting heart rate has sometimes been used as a marker of training status. It is reasonable to assume that the relationship between heart rate and training status should be more evident during sleep when extraneous factors that may influence heart rate are reduced. Therefore the aim of the study was to assess the repeatability of monitoring heart rate during sleep when training status remained unchanged, to determine if this measurement had sufficient precision to be used as a marker of train...

  11. Resting heart rate and cardiovascular events: risk factor or risk ...

    African Journals Online (AJOL)

    Review: Resting heart rate and cardiovascular events: risk factor or risk marker? 128. Vol 52 No 2. SA Fam Pract 2010. SA Fam Pract 2010;52(2): 128-129. Heart rate in epidemiological studies. Over the last 25 years numerous reports demonstrated a significant association between resting heart rate and all- cause mortality ...

  12. The computation of evoked heart rate and blood pressure

    NARCIS (Netherlands)

    Koers, G.; Mulder, L.J.M.; van der Veen, F.M.

    1999-01-01

    For many years psychophysiologists have been interested in stimulus related changes in heart rate and blood pressure. To represent these evoked heart rate and blood pressure patterns, heart rate and blood pressure data have to be transformed into equidistant time series. This paper presents an

  13. HEART-RATE-VARIABILITY SPECTRA BASED ON NONEQUIDISTANT SAMPLING - THE SPECTRUM OF COUNTS AND THE INSTANTANEOUS HEART-RATE SPECTRUM

    NARCIS (Netherlands)

    VANSTEENIS, HG; TULEN, JHM; MULDER, LJM

    This paper compares two methods to estimate heart rate variability spectra i.e., the spectrum of counts and the instantaneous heart rate spectrum. Contrary to Fourier techniques based on equidistant sampling of the interbeat intervals, the spectrum of counts of the instantaneous heart rate spectrum

  14. The Impact of Personalized Risk Feedback on Mexican Americans' Perceived Risk for Heart Disease and Diabetes

    Science.gov (United States)

    Hovick, Shelly R.; Wilkinson, Anna V.; Ashida, Sato; de Heer, Hendrik D.; Koehly, Laura M.

    2014-01-01

    Little is known about the effect of personalized risk information on risk perceptions over time, particularly among ethnically diverse subpopulations. The present study examines Mexican American's (MAs) risk perceptions for heart disease and diabetes at baseline and following receipt of risk feedback based on family health history. Participants…

  15. Listen to Your Heart: When False Somatic Feedback Shapes Moral Behavior

    Science.gov (United States)

    Gu, Jun; Zhong, Chen-Bo; Page-Gould, Elizabeth

    2013-01-01

    A pounding heart is a common symptom people experience when confronting moral dilemmas. The authors conducted 4 experiments using a false feedback paradigm to explore whether and when listening to a fast (vs. normal) heartbeat sound shaped ethical behavior. Study 1 found that perceived fast heartbeat increased volunteering for a just cause. Study…

  16. Heart rate monitoring during training and competition in cyclists.

    Science.gov (United States)

    Jeukendrup, A; VanDiemen, A

    1998-01-01

    To obtain optimal training effects and avoid overtraining, it is necessary to monitor the intensity of training. In cycling, speed is not an accurate indicator of exercise intensity, and therefore alternatives have to be found to monitor exercise intensity during training and competition. Power output may be the most direct indicator, but heart rate is easier to monitor and measure. There are, however, limitations that have to be taken into account when using a heart rate monitor. For example, the position on the bicycle may change heart rate at a given exercise intensity. More important, however, is the increase in heart rate over time, a phenomenon described as 'cardiac drift'. Cardiac drift can change the heart rate-power output relationship drastically, especially in hot environments or at altitude. It is important to determine whether one is interested in monitoring exercise intensity per se or measuring whole-body stress. Power output may be a better indicator of the former and heart rate may, under many conditions, be a better indicator of the latter. Heart rate can be used to evaluate a cyclist after training or competition, or to determine the exercise intensity during training. Heart rate monitoring is very useful in the detection of early overtraining, especially in combination with lactate curves and questionnaires. During overtraining, maximal heart rates as well as submaximal heart rates may be decreased, while resting and, in particular, sleeping - heart rates may be increased.

  17. Heart rate awareness in patients with chronic stable heart failure. A multi-center observational study.

    LENUS (Irish Health Repository)

    Moran, D

    2014-08-23

    We assessed adherence to European Society of Cardiology heart rate guidelines (i.e. heart rates less than 70bpm) in patients with chronic stable heart failure. We also investigated the percent of patients on target doses of rate controlling drugs.

  18. High readmission rate after heart valve surgery

    DEFF Research Database (Denmark)

    Sibilitz, K L; Berg, S K; Thygesen, Lau Caspar

    2015-01-01

    age (hazard ratio (95% CI): 1.3 (1.0-1.6)), male sex (1.2 (1.0-1.5)), mitral valve surgery (1.3 (1.0-1.6)), and infective endocarditis after surgery (1.8 (1.1-3.0), p: 0.01) predicted readmission, whereas higher age (2.3 (1.0-5.4)), higher comorbidity score (3.2 (1.8-6.0)), and infective endocarditis......BACKGROUND: After heart valve surgery, knowledge on long-term self-reported health status and readmission is lacking. Thus, the optimal strategy for out-patient management after surgery remains unclear. METHODS: Using a nationwide survey with linkage to Danish registers with one year follow-up, we...... included all adults 6-12 months after heart valve surgery irrespective of valve procedure, during Jan-June 2011 (n = 867). Participants completed a questionnaire regarding health-status (n = 742), and answers were compared with age- and sex-matched healthy controls. Readmission rates and mortality were...

  19. Fetal heart rate after vibroacoustic stimulation.

    Science.gov (United States)

    Hoh, Jeong Kyu; Park, Young-Sun; Cha, Kyung-Joon; Park, Moon-Il

    2009-07-01

    To define reference ranges for fetal heart rate (FHR) parameters after vibroacoustic stimulation (VAS) according to gestational age by determining the relationship between FHR and gestational age using a computerized analysis system. Data were analyzed from 3453 women using 10-minute observational recordings during nonstress testing (NST) and VAS testing. FHR parameters were analyzed according to gestational age. All FHR parameters were related to gestational age except for mean baseline FHR, which did not vary significantly with gestational age. All other parameters followed trends similar to the NST results, except for decelerations. FHR parameters after VAS differed significantly according to gestational age. The results suggest that the gestational age of the fetus should be considered when interpreting FHR patterns after VAS.

  20. Heart rate variability in familial Mediterranean fever.

    Science.gov (United States)

    Nussinovitch, Naomi; Livneh, Avi; Katz, Keren; Langevitz, Pnina; Feld, Olga; Nussinovitch, Moshe; Volovitz, Benjamin; Lidar, Merav; Nussinovitch, Udi

    2011-01-01

    Familial Mediterranean fever (FMF) is a hereditary disease, characterized by recurrent episodes of fever and polyserositis. Heart rate variability (HRV) is a powerful, simple and reliable technique to evaluate autonomic nervous system function. Previous studies of physiologic parameters during tilt-test have suggested that patients with FMF have abnormal cardiovascular reactivity and occult dysautonomia. Prompted by these findings, the present study sought to evaluate HRV in patients with FMF, at rest and in the standing position. The study sample included 34 patients with FMF and 34 sex- and age-matched control subjects. All underwent electrocardiography according to strict criteria. HRV parameters were computed with custom-made software. There was no significant difference in HRV parameters, in either the supine or standing position, between the FMF and control groups. In both groups, the upright position was associated with a significant decrease, when compared with the supine position, in maximal RR interval, minimal RR, average RR, root square of successive differences in RR interval, number of intervals differing by >50 ms from preceding interval (NN50), NN50 divided by total number of intervals (pNN50) and high-frequency components as well as a significant increase in average heart rate, very low frequency or low-frequency components, low-frequency/high-frequency components ratio and total power. In conclusion, patients with FMF who are continuously treated with low-dose colchicine have not developed amyloidosis and have normal HRV parameters in the supine and upright position. Further investigation of occult dysautonomia in FMF is needed.

  1. Biophysical characterization of the underappreciated and important relationship between heart rate variability and heart rate.

    Science.gov (United States)

    Monfredi, Oliver; Lyashkov, Alexey E; Johnsen, Anne-Berit; Inada, Shin; Schneider, Heiko; Wang, Ruoxi; Nirmalan, Mahesh; Wisloff, Ulrik; Maltsev, Victor A; Lakatta, Edward G; Zhang, Henggui; Boyett, Mark R

    2014-12-01

    Heart rate (HR) variability (HRV; beat-to-beat changes in the R-wave to R-wave interval) has attracted considerable attention during the past 30+ years (PubMed currently lists >17 000 publications). Clinically, a decrease in HRV is correlated to higher morbidity and mortality in diverse conditions, from heart disease to fetal distress. It is usually attributed to fluctuation in cardiac autonomic nerve activity. We calculated HRV parameters from a variety of cardiac preparations (including humans, living animals, Langendorff-perfused heart, and single sinoatrial nodal cell) in diverse species, combining this with data from previously published articles. We show that regardless of conditions, there is a universal exponential decay-like relationship between HRV and HR. Using 2 biophysical models, we develop a theory for this and confirm that HRV is primarily dependent on HR and cannot be used in any simple way to assess autonomic nerve activity to the heart. We suggest that the correlation between a change in HRV and altered morbidity and mortality is substantially attributable to the concurrent change in HR. This calls for re-evaluation of the findings from many articles that have not adjusted properly or at all for HR differences when comparing HRV in multiple circumstances. © 2014 American Heart Association, Inc.

  2. Influence of heavy cigarette smoking on heart rate variability and heart rate turbulence parameters

    DEFF Research Database (Denmark)

    Cagirci, Goksel; Cay, Serkan; Karakurt, Ozlem

    2009-01-01

    BACKGROUND: Cigarette smoking increases the risk of cardiovascular events related with several mechanisms. The most suggested mechanism is increased activity of sympathetic nervous system. Heart rate variability (HRV) and heart rate turbulence (HRT) has been shown to be independent and powerful...... predictors of mortality in a specific group of cardiac patients. The goal of this study was to assess the effect of heavy cigarette smoking on cardiac autonomic function using HRV and HRT analyses. METHODS: Heavy cigarette smoking was defined as more than 20 cigarettes smoked per day. Heavy cigarette smokers......, 69 subjects and nonsmokers 74 subjects (control group) were enrolled in this study. HRV and HRT analyses [turbulence onset (TO) and turbulence slope (TS)] were assessed from 24-hour Holter recordings. RESULTS: The values of TO were significantly higher in heavy cigarette smokers than control group...

  3. Genome-wide association studies and resting heart rate

    DEFF Research Database (Denmark)

    Oskari Kilpeläinen, Tuomas

    2016-01-01

    Genome-wide association studies (GWASs) have revolutionized the search for genetic variants regulating resting heart rate. In the last 10 years, GWASs have led to the identification of at least 21 novel heart rate loci. These discoveries have provided valuable insights into the mechanisms...... and pathways that regulate heart rate and link heart rate to cardiovascular morbidity and mortality. GWASs capture majority of genetic variation in a population sample by utilizing high-throughput genotyping chips measuring genotypes for up to several millions of SNPs across the genome in thousands...... of individuals. This allows the identification of the strongest heart rate associated signals at genome-wide level. While GWASs provide robust statistical evidence of the association of a given genetic locus with heart rate, they are only the starting point for detailed follow-up studies to locate the causal...

  4. Resting heart rate and the risk of heart failure in healthy adults: the Rotterdam Study.

    Science.gov (United States)

    Nanchen, David; Leening, Maarten J G; Locatelli, Isabella; Cornuz, Jacques; Kors, Jan A; Heeringa, Jan; Deckers, Jaap W; Hofman, Albert; Franco, Oscar H; Stricker, Bruno H Ch; Witteman, Jacqueline C M; Dehghan, Abbas

    2013-05-01

    An elevated resting heart rate is associated with rehospitalization for heart failure and is a modifiable risk factor in heart failure patients. We aimed to examine the association between resting heart rate and incident heart failure in a population-based cohort study of healthy adults without pre-existing overt heart disease. We studied 4768 men and women aged ≥55 years from the population-based Rotterdam Study. We excluded participants with prevalent heart failure, coronary heart disease, pacemaker, atrial fibrillation, atrioventricular block, and those using β-blockers or calcium channel blockers. We used extended Cox models allowing for time-dependent variation of resting heart rate along follow-up. During a median of 14.6 years of follow-up, 656 participants developed heart failure. The risk of heart failure was higher in men with higher resting heart rate. For each increment of 10 beats per minute, the multivariable adjusted hazard ratios in men were 1.16 (95% confidence interval, 1.05-1.28; P=0.005) in the time-fixed heart rate model and 1.13 (95% confidence interval, 1.02-1.25; P=0.017) in the time-dependent heart rate model. The association could not be demonstrated in women (P for interaction=0.004). Censoring participants for incident coronary heart disease or using time-dependent models to account for the use of β-blockers or calcium channel blockers during follow-up did not alter the results. Baseline or persistent higher resting heart rate is an independent risk factor for the development of heart failure in healthy older men in the general population.

  5. Heart rate variability and blood pressure during dynamic and static exercise at similar heart rate levels.

    Science.gov (United States)

    Weippert, Matthias; Behrens, Kristin; Rieger, Annika; Stoll, Regina; Kreuzfeld, Steffi

    2013-01-01

    Aim was to elucidate autonomic responses to dynamic and static (isometric) exercise of the lower limbs eliciting the same moderate heart rate (HR) response. 23 males performed two kinds of voluntary exercise in a supine position at similar heart rates: static exercise (SE) of the lower limbs (static leg press) and dynamic exercise (DE) of the lower limbs (cycling). Subjective effort, systolic (SBP) and diastolic blood pressure (DBP), mean arterial pressure (MAP), rate pressure product (RPP) and the time between consecutive heart beats (RR-intervals) were measured. Time-domain (SDNN, RMSSD), frequency-domain (power in the low and high frequency band (LFP, HFP)) and geometric measures (SD1, SD2) as well as non-linear measures of regularity (approximate entropy (ApEn), sample entropy (SampEn) and correlation dimension D2) were calculated. Although HR was similar during both exercise conditions (88±10 bpm), subjective effort, SBP, DBP, MAP and RPP were significantly enhanced during SE. HRV indicators representing overall variability (SDNN, SD 2) and vagal modulated variability (RMSSD, HFP, SD 1) were increased. LFP, thought to be modulated by both autonomic branches, tended to be higher during SE. ApEn and SampEn were decreased whereas D2 was enhanced during SE. It can be concluded that autonomic control processes during SE and DE were qualitatively different despite similar heart rate levels. The differences were reflected by blood pressure and HRV indices. HRV-measures indicated a stronger vagal cardiac activity during SE, while blood pressure response indicated a stronger sympathetic efferent activity to the vessels. The elevated vagal cardiac activity during SE might be a response mechanism, compensating a possible co-activation of sympathetic cardiac efferents, as HR and LF/HF was similar and LFP tended to be higher. However, this conclusion must be drawn cautiously as there is no HRV-marker reflecting "pure" sympathetic cardiac activity.

  6. Heart Rate, Life Expectancy and the Cardiovascular System: Therapeutic Considerations.

    Science.gov (United States)

    Boudoulas, Konstantinos Dean; Borer, Jeffrey S; Boudoulas, Harisios

    2015-01-01

    It has long been known that life span is inversely related to resting heart rate in most organisms. This association between heart rate and survival has been attributed to the metabolic rate, which is greater in smaller animals and is directly associated with heart rate. Studies have shown that heart rate is related to survival in apparently healthy individuals and in patients with different underlying cardiovascular diseases. A decrease in heart rate due to therapeutic interventions may result in an increase in survival. However, there are many factors regulating heart rate, and it is quite plausible that these may independently affect life expectancy. Nonetheless, a fast heart rate itself affects the cardiovascular system in multiple ways (it increases ventricular work, myocardial oxygen consumption, endothelial stress, aortic/arterial stiffness, decreases myocardial oxygen supply, other) which, in turn, may affect survival. In this brief review, the effects of heart rate on the heart, arterial system and survival will be discussed. © 2015 S. Karger AG, Basel.

  7. Accuracy of smartphone apps for heart rate measurement.

    Science.gov (United States)

    Coppetti, Thomas; Brauchlin, Andreas; Müggler, Simon; Attinger-Toller, Adrian; Templin, Christian; Schönrath, Felix; Hellermann, Jens; Lüscher, Thomas F; Biaggi, Patric; Wyss, Christophe A

    2017-08-01

    Background Smartphone manufacturers offer mobile health monitoring technology to their customers, including apps using the built-in camera for heart rate assessment. This study aimed to test the diagnostic accuracy of such heart rate measuring apps in clinical practice. Methods The feasibility and accuracy of measuring heart rate was tested on four commercially available apps using both iPhone 4 and iPhone 5. 'Instant Heart Rate' (IHR) and 'Heart Fitness' (HF) work with contact photoplethysmography (contact of fingertip to built-in camera), while 'Whats My Heart Rate' (WMH) and 'Cardiio Version' (CAR) work with non-contact photoplethysmography. The measurements were compared to electrocardiogram and pulse oximetry-derived heart rate. Results Heart rate measurement using app-based photoplethysmography was performed on 108 randomly selected patients. The electrocardiogram-derived heart rate correlated well with pulse oximetry ( r = 0.92), IHR ( r = 0.83) and HF ( r = 0.96), but somewhat less with WMH ( r = 0.62) and CAR ( r = 0.60). The accuracy of app-measured heart rate as compared to electrocardiogram, reported as mean absolute error (in bpm ± standard error) was 2 ± 0.35 (pulse oximetry), 4.5 ± 1.1 (IHR), 2 ± 0.5 (HF), 7.1 ± 1.4 (WMH) and 8.1 ± 1.4 (CAR). Conclusions We found substantial performance differences between the four studied heart rate measuring apps. The two contact photoplethysmography-based apps had higher feasibility and better accuracy for heart rate measurement than the two non-contact photoplethysmography-based apps.

  8. Factors underlying the perception of effort during constant heart rate running above and below the critical heart rate.

    Science.gov (United States)

    Bergstrom, Haley C; Housh, Terry J; Cochrane, Kristen C; Jenkins, Nathaniel D M; Zuniga, Jorge M; Buckner, Samuel L; Goldsmith, Jacob A; Schmidt, Richard J; Johnson, Glen O; Cramer, Joel T

    2015-10-01

    This study examined: (1) the sustainability of the critical heart rate (CHR) minus 5 b min(-1) (CHR - 5) and CHR plus 5 b min(-1) (CHR + 5); (2) the ratings of perceived exertion (RPE), velocity, [Formula: see text], minute ventilation ([Formula: see text]), breathing frequency (f b ), and electromyographic amplitude (EMG AMP) and EMG mean power frequency (MPF) responses during treadmill running at CHR - 5 and CHR + 5 to determine what factors underlie the perception of effort when heart rate (HR) is held constant; and (3) the relationships among RPE, [Formula: see text], and HR, to determine which variable(s) reflect exhaustion during exercise performed at a constant HR. The CHR was determined in eight runners (mean ± SD; age = 24 ± 3 years) from a series of four exhaustive, constant velocity runs. The RPE, velocity, [Formula: see text], [Formula: see text], f b , EMG AMP, and EMG MPF responses were recorded during runs at the CHR - 5 and CHR + 5. At CHR - 5, RPE, f b, and EMG MPF increased, while velocity, [Formula: see text], [Formula: see text], and EMG AMP decreased. At CHR + 5, RPE and f b increased, velocity, [Formula: see text], [Formula: see text], and EMG AMP decreased, and EMG MPF remained constant. The close association between f b and RPE throughout the run at CHR - 5 and during the last 50 % of the run at CHR + 5 indicated that muscle afferents may have provided feedback from metabolic and mechanical stimuli that contributed to the perceptual responses. In addition, only RPE consistently indicated exhaustion and the current findings supported its use to monitor exercise performed at a constant HR.

  9. Increased heart rate is associated with a prothrombotic state: The Framingham Heart Study.

    Science.gov (United States)

    Tofler, Geoffrey H; Massaro, Joseph; Levy, Daniel A; Sutherland, Patrice A; Buckley, Thomas; D'Agostino, Ralph B

    2017-03-01

    Background Although a higher heart rate is associated with an increased risk of cardiovascular disease, the mechanism is not well understood. As thrombosis has an important role in plaque development and acute coronary syndromes, the increase related to heart rate may result from a prothrombotic imbalance. Methods We investigated the relation between heart rate and thrombotic potential in 3451 participants from the Offspring Cohort of the Framingham Heart Study (mean age 54 years, 55% women). Participants were divided into quintiles based on heart rate derived from a resting electrocardiogram. Results Higher heart rates were associated with significant age-adjusted increases in fibrinogen, viscosity, factor VII antigen, and impaired fibrinolytic potential (plasminogen activator inhibitor and tissue plasminogen activator antigen) among men and women, and von Willebrand factor antigen among men. Fibrinogen levels were 9% higher among men with a heart rate of 80.9 ± 8.1 beats/min (quintile 5) vs. 50.0 ± 3.9 beats/min (quintile 1) (314 vs. 287 mg/dl, p heart rates are associated with a prothrombotic state. Because these factors are also associated with endothelial dysfunction and inflammation, these findings are consistent with an injurious effect of higher heart rates on the endothelium. Measures to reduce thrombotic potential may be of particular value in people with higher heart rates.

  10. HEART RATE DURING SLEEP: IMPLICATIONS FOR MONITORING TRAINING STATUS

    Directory of Open Access Journals (Sweden)

    Miriam R. Waldeck

    2003-12-01

    Full Text Available Resting heart rate has sometimes been used as a marker of training status. It is reasonable to assume that the relationship between heart rate and training status should be more evident during sleep when extraneous factors that may influence heart rate are reduced. Therefore the aim of the study was to assess the repeatability of monitoring heart rate during sleep when training status remained unchanged, to determine if this measurement had sufficient precision to be used as a marker of training status. The heart rate of ten female subjects was monitored for 24 hours on three occasions over three weeks whilst training status remained unchanged. Average, minimum and maximum heart rate during sleep was calculated. The average heart rate of the group during sleep was similar on each of the three tests (65 ± 9, 63 ± 6 and 67 ± 7 beats·min-1 respectively. The range in minimum heart rate variation during sleep for all subjects over the three testing sessions was from 0 to 10 beats·min-1 (mean = 5 ± 3 beats·min-1 and for maximum heart rate variation was 2 to 31 beats·min-1 (mean = 13 ± 9 beats·min-1. In summary it was found that on an individual basis the minimum heart rate during sleep varied by about 8 beats·min-1. This amount of intrinsic day-to-day variation needs to be considered when changes in heart rate that may occur with changes in training status are interpreted

  11. Heart rate during sleep: implications for monitoring training status.

    Science.gov (United States)

    Waldeck, Miriam R; Lambert, Michael I

    2003-12-01

    Resting heart rate has sometimes been used as a marker of training status. It is reasonable to assume that the relationship between heart rate and training status should be more evident during sleep when extraneous factors that may influence heart rate are reduced. Therefore the aim of the study was to assess the repeatability of monitoring heart rate during sleep when training status remained unchanged, to determine if this measurement had sufficient precision to be used as a marker of training status. The heart rate of ten female subjects was monitored for 24 hours on three occasions over three weeks whilst training status remained unchanged. Average, minimum and maximum heart rate during sleep was calculated. The average heart rate of the group during sleep was similar on each of the three tests (65 ± 9, 63 ± 6 and 67 ± 7 beats·min(-1) respectively). The range in minimum heart rate variation during sleep for all subjects over the three testing sessions was from 0 to 10 beats·min(-1) (mean = 5 ± 3 beats·min(-1)) and for maximum heart rate variation was 2 to 31 beats·min(-1) (mean = 13 ± 9 beats·min(-1)). In summary it was found that on an individual basis the minimum heart rate during sleep varied by about 8 beats·min(-1). This amount of intrinsic day-to-day variation needs to be considered when changes in heart rate that may occur with changes in training status are interpreted.

  12. Erythrocyte sedimentation rate as a marker for coronary heart disease.

    Science.gov (United States)

    Yayan, Josef

    2012-01-01

    Patients with angina pectoris or myocardial infarction frequently present without evidence of cardiac-specific heart enzymes by laboratory analysis or specific pathologic electro-cardiogram findings. The current study analyzed the efficacy of the erythrocyte sedimentation rate as an additional potential indicator for coronary heart disease, the aim being to enable quicker identification of patients with angina pectoris or myocardial infarction so that they can be more rapidly treated. Patients with angina pectoris or myocardial infarction who had undergone a heart catheter examination were included in the study. The diagnosis of acute coronary heart disease was made by the physician who performed coronary angiography. Patients without coronary heart disease were used as a control group. The erythrocyte sedimentation rate was measured in all patients. Patients with angina pectoris or myocardial infarction and an inflammatory or tumor disease were excluded. The erythrocyte sedimentation rate was prolonged in 79 (58.09%) of 136 patients; 69 (50.74%) patients (95% confidence interval ±8.4%, 42.34%-59.14%) had coronary heart disease and a prolonged erythrocyte sedimentation rate. The erythrocyte sedimentation rate was prolonged in ten (7.35%) patients (95% confidence interval ±4.39%, 2.96%-11.74%) without coronary heart disease by coronary angiography. The specificity of the erythrocyte sedimentation rate for coronary heart disease was 70.59% and the sensitivity was 67.65%. Erythrocyte sedimentation rate may be a useful additional diagnostic criterion for coronary heart disease.

  13. Reduced intrinsic heart rate is associated with reduced arrhythmic susceptibility in guinea-pig heart.

    Science.gov (United States)

    Osadchii, Oleg E

    2014-12-01

    In the clinical setting, patients with slower resting heart rate are less prone to cardiovascular death compared with those with elevated heart rate. However, electrophysiological adaptations associated with reduced cardiac rhythm have not been thoroughly explored. In this study, relationships between intrinsic heart rate and arrhythmic susceptibility were examined by assessments of action potential duration (APD) rate adaptation and inducibility of repolarization alternans in sinoatrial node (SAN)-driven and atrioventricular (AV)-blocked guinea-pig hearts perfused with Langendorff apparatus. Electrocardiograms, epicardial monophasic action potentials, and effective refractory periods (ERP) were assessed in normokalemic and hypokalemic conditions. Slower basal heart rate in AV-blocked hearts was associated with prolonged ventricular repolarization during spontaneous beating, and with attenuated APD shortening at increased cardiac activation rates during dynamic pacing, when compared with SAN-driven hearts. During hypokalemic perfusion, the inducibility of repolarization alternans and tachyarrhythmia by rapid pacing was found to be lower in AV-blocked hearts. This difference was ascribed to prolonged ERP in the setting of reduced basal heart rate, which prevented ventricular capture at critically short pacing intervals required to induce arrhythmia. Reduced basal heart rate is associated with electrophysiological changes that prevent electrical instability upon an abrupt cardiac acceleration.

  14. Maternal Psychopathology Influences Infant Heart Rate Variability: Generation R Study

    NARCIS (Netherlands)

    B. Dierckx (Bram); J.H.M. Tulen (Joke); M.P. Lambregtse-van den Berg (Mijke); A. Tharner (Anne); V.W.V. Jaddoe (Vincent); H.A. Moll (Henriëtte); A. Hofman (Albert); F.C. Verhulst (Frank); H.W. Tiemeier (Henning)

    2009-01-01

    textabstractAbstract OBJECTIVE: To assess the determinants of heart rate (HR) and heart rate variability (HRV) in children. The autonomic nervous system as measured by HR and HRV is considered a biological marker of psychopathology in children. METHODS: We examined the relationship of maternal

  15. Using photoplethysmography in heart rate monitoring of patients with epilepsy

    NARCIS (Netherlands)

    van Andel, Judith; Ungureanu, Constantin; Aarts, Ronald; Leijten, Frans; Arends, Johan

    2015-01-01

    Heart rate is a useful neurophysiological sign when monitoring seizures in patients with epilepsy. In an ambulatory setting, heart rate is measured with ECG involving electrodes on the skin. This method is uncomfortable which is burdensome for patients and is sensitive to motion artifacts, which

  16. Do high fetal catecholamine levels affect heart rate variability and ...

    African Journals Online (AJOL)

    Objectives. To deternrine the relationship between Umbilical arterial catecholamine levels and fetal heart rate variability and meconium passage. Study design. A prospective descriptive study was perfonned. Umbilical artery catecholamine levels were measured in 55 newborns and correlated with fetal heart rate before ...

  17. The Correlation Between Ultrasound-Measured Fetal Heart Rate ...

    African Journals Online (AJOL)

    A total of 400 apparently healthy pregnant women with singleton fetuses from Enugu, Southeast Nigeria were randomly selected for the study. The aims of the study are to establish: a normogram for fetal heart rate (FHR) and the relationship between fetal heart rate and gestational age (GA) by 2–D ultrasound. Crown rump ...

  18. Retrospective low heart rate variability overview in Jos, Nigeria ...

    African Journals Online (AJOL)

    Background: Heart Rate Variability (HRV) describes the variations of both instantaneous heart rate and R-R intervals in an electrocardiogram. Low HRV is considered to be a non-invasive measurement of autonomic inactivity and propensity lethal arrhythmias. Methodology: This was a retrospective study of patients with ...

  19. Effects of Malaria on Blood Pressure, Heart Rate, Electrocardiogram ...

    African Journals Online (AJOL)

    The effect of malaria on blood pressure, heart rate, electrocardiogram and the cardiovascular responses to postural change were studied in malaria patients. Blood pressure was measured by the sphygmomanometric-auscultatory method. Standard ECG machine was used to record the electrocardiogram. Heart rate was ...

  20. A comparison between heart rate and heart rate variability as indicators of cardiac health and fitness

    Directory of Open Access Journals (Sweden)

    Catharina Cornelia Grant

    2013-11-01

    Full Text Available Quantification of cardiac autonomic activity and control via heart rate (HR and heart rate variability (HRV is known to provide prognostic information in clinical populations. Issues with regard to standardisation and interpretation of HRV data make the use of the more easily accessible HR on its own as an indicator of autonomic cardiac control very appealing. The aim of this study was to investigate the strength of associations between an important cardio vascular health metric such as VO2max and the following: HR, HRV indicators and heart rate normalised HRV indicators. A cross sectional descriptive study was done including 145 healthy volunteers aged between 18 and 22 years. HRV was quantified by time domain, frequency domain and Poincaré plot analysis. Indirect VO2max was determined using the Multistage Coopers test. The Pearson correlation coefficient was calculated to quantify the strength of the associations. Both simple linear and multiple stepwise regressions were performed to be able to discriminate between the role of the individual indicators as well as their combined association with VO2max. Only HR, RR interval and pNN50 showed significant (p<0.01, p<0.01 and p=0.03 correlations with VO2max. Stepwise multiple regression indicated that, when combining all HRV indicators the most important predictor of cardio vascular fitness as represented by VO2max, is HR. HR explains 17% of the variation, while the inclusion of HF (high frequency HRV indicator added only an additional 3.1% to the coefficient of determination. Results also showed when testing the normalised indicators, HR explained of the largest percentage of the changes in VO2max (16.5%. Thus HR on its own is the most important predictor of changes in an important cardiac health metric such as VO2max. These results may indicate that during investigation of exercise ability (VO2max phenomena, quantification of HRV may not add significant value.

  1. Fetal Heart Rate Monitoring from Phonocardiograph Signal Using Repetition Frequency of Heart Sounds

    OpenAIRE

    Hong Tang; Ting Li; Tianshuang Qiu; Yongwan Park

    2016-01-01

    As a passive, harmless, and low-cost diagnosis tool, fetal heart rate (FHR) monitoring based on fetal phonocardiography (fPCG) signal is alternative to ultrasonographic cardiotocography. Previous fPCG-based methods commonly relied on the time difference of detected heart sound bursts. However, the performance is unavoidable to degrade due to missed heart sounds in very low signal-to-noise ratio environments. This paper proposes a FHR monitoring method using repetition frequency of heart sound...

  2. Assessing Heart Rate in Physical Education. Assessment Series: K-12 Physical Education.

    Science.gov (United States)

    Buck, Marilyn M.

    This guide discusses the assessment of heart rate and, in particular, the assessment of heart rate using a heart monitor. Part 1, "Foundation for the Use of Heart Rate," reviews literature about heart rate assessment and heart rate monitors, offering an overview of national guidelines for physical activity. It focuses on the importance…

  3. The clinical significance of detection to heart rate deceleration capacity and heart rate variability in patients with chronic heart failure

    Directory of Open Access Journals (Sweden)

    Jiang-rong Zhou

    2015-01-01

    Full Text Available Objective: To study the change of heart rate deceleration capacity ( DC and heart rate variability in patients with chronic heart failure (CHF and its relationship with left ventricular ejection fraction (LVEF. Methods: DC, LVEF, time and frequency domain parameters of HRV were measured in 66 patients with CHF and 34 healthy adults (control group by using 24h Holter recordings and Echocardiography. The standard deviation of normal R-R intervals( SDNN, squares of differences between adjacent NN intervals ( RMSSD,low frequency power( LFn and high frequency power( HFn and the changes of LVEF were compared between  the two groups,the relationship between DC,LVEF and HRV were studied in patients with CHF. Results: The median value of DC in the patients with CHF was significantly lower than that in control group( 3.1 ± 2.4 ms vs 7.2 ± 1.3 ms,P <0.01.Incidence of abnormal DC in the CHF group was 57.5%,which was significantly higher than that in the control group (P <0.01.The HRV index, including SDNN、RMSSD、LFn、HFn, in the CHF group was significantly lower than that in normal control group (P < 0.01. Significant positive correlation between HRV index and LVEF were confirmed (P < 0.01. Conclusions: DC and HRV index are lower in patients with CHF and have a good correlation with the left ventricular ejection fraction.

  4. The effect of heart rate on the heart rate variability response to autonomic interventions.

    Science.gov (United States)

    Billman, George E

    2013-01-01

    Heart rate variability (HRV), the beat-to-beat variation in either heart rate (HR) or heart period (R-R interval), has become a popular clinical and investigational tool to quantify cardiac autonomic regulation. However, it is not widely appreciated that, due to the inverse curvilinear relationship between HR and R-R interval, HR per se can profoundly influence HRV. It is, therefore, critical to correct HRV for the prevailing HR particularly, as HR changes in response to autonomic neural activation or inhibition. The present study evaluated the effects of HR on the HRV response to autonomic interventions that either increased (submaximal exercise, n = 25 or baroreceptor reflex activation, n = 20) or reduced (pharmacological blockade: β-adrenergic receptor, muscarinic receptor antagonists alone and in combination, n = 25, or bilateral cervical vagotomy, n = 9) autonomic neural activity in a canine model. Both total (RR interval standard deviation, RRSD) and the high frequency (HF) variability (HF, 0.24-1.04 Hz) were determined before and in response to an autonomic intervention. All interventions that reduced or abolished cardiac parasympathetic regulation provoked large reductions in HRV even after HR correction [division by mean RRsec or (mean RRsec)(2) for RRSD and HF, respectively] while interventions that reduced HR yielded mixed results. β-adrenergic receptor blockade reduced HRV (RRSD but not HF) while both RRSD and HF increased in response to increases in arterial blood (baroreceptor reflex activation) even after HR correction. These data suggest that the physiological basis for HRV is revealed after correction for prevailing HR and, further, that cardiac parasympathetic activity is responsible for a major portion of the HRV in the dog.

  5. The Effect of Heart Rate on the Heart Rate Variability Response to Autonomic Interventions

    Directory of Open Access Journals (Sweden)

    George E Billman

    2013-08-01

    Full Text Available Heart rate variability (HRV, the beat-to-beat variation in either heart rate (HR or heart period (R-R interval, has become a popular clinical and investigational tool to quantify cardiac autonomic regulation. However, it is not widely appreciated that, due to the inverse curvilinear relationship between HR and R-R interval, HR per se can profoundly influence HRV. It is, therefore, critical to correct HRV for the prevailing HR particularly, as HR changes in response to autonomic neural activation or inhibition. The present study evaluated the effects of HR on the HRV response to autonomic interventions that either increased (submaximal exercise, n = 25 or baroreceptor reflex activation, n = 20 or reduced (pharmacological blockade: β-adrenergic receptor, muscarinic receptor antagonists alone and in combination, n = 25, or bilateral cervical vagotomy, n = 9 autonomic neural activity in a canine model. Both total (RR interval standard deviation, RRSD and the high frequency variability (HF, 0.2 to 1.04 Hz were determined before and in response to an autonomic intervention. All interventions that reduced or abolished cardiac parasympathetic regulation provoked large reductions in HRV even after HR correction [division by mean RRsec or (mean RRsec2 for RRSD and HF, respectively] while interventions that reduced HR yielded mixed results. β-adrenergic receptor blockade reduced HRV (RRSD but not HF while both RRSD and HF increased in response to increases in arterial blood (baroreceptor reflex activation even after HR correction. These data suggest that the physiological basis for HRV is revealed after correction for prevailing HR and, further, that cardiac parasympathetic activity is responsible for a major portion of the HRV in the dog.

  6. Firefighter Incident Rehabilitation: Interpreting Heart Rate Responses.

    Science.gov (United States)

    Smith, Denise L; Haller, Jeannie M; Benedict, Ron; Moore-Merrell, Lori

    2016-01-01

    The primary objective of this observational study was to document the heart rate (HR) responses of firefighters during incident rehabilitation following firefighting activity in a high-rise building with a simulated fire on the 10th floor. Additionally, the study investigated potential factors, including firefighting workload, ambient temperature, firefighter movement, and individual characteristics, that may have affected HR during recovery. Firefighters (n = 198) were assigned to perform a simulation of fire suppression, search and rescue, or material support during one of six firefighting trials that involved different crew sizes and ascent modes, and were performed in different environmental conditions. After completing the simulated firefighting activity, firefighters reported to a rehabilitation area on the 8th floor. The rehabilitation area was staffed by firefighter/paramedics. HR was monitored continuously during simulated firefighting activity and a 15-minute rehabilitation period. Average HR during rehabilitation (HRmean) was calculated and compared across trials. Simulated firefighting activity was performed in the summer in Virginia, USA, and ambient conditions varied among trials (mean ± SD: 31 ± 4°C; 46 ± 15% relative humidity; 32 ± 4°C heat index). Duration of simulated firefighting activity ranged from 12.0 to 20.3 minutes among trials (mean: 15.4 ± 5.2 minutes). Over all trials, mean peak HR during simulations was 173 ± 18 beats·min(-1). Mean HR over all trials at entry into rehabilitation was 149 ± 24 beats·min(-1). Following 15 minutes of recovery, mean HR over all trials was 126 ± 23 beats·min(-1). Exploratory analyses revealed that higher workload during firefighting (stair trials), higher ambient temperature (≥30°C), greater movement during rehabilitation (≥0.1 g-force), higher age (≥45 years), and higher BMI (≥30.0 kg·m(-2)) were associated with higher HR responses during rehabilitation. During complex emergency

  7. Long‐term Cardiovascular Risks Associated With an Elevated Heart Rate: The Framingham Heart Study

    Science.gov (United States)

    Ho, Jennifer E.; Larson, Martin G.; Ghorbani, Anahita; Cheng, Susan; Coglianese, Erin E.; Vasan, Ramachandran S.; Wang, Thomas J.

    2014-01-01

    Background Higher heart rate has been associated with an adverse prognosis, but most prior studies focused on individuals with known cardiovascular disease or examined a limited number of outcomes. We sought to examine the association of baseline heart rate with both fatal and nonfatal outcomes during 2 decades of follow‐up. Methods and Results Our study included 4058 Framingham Heart Study participants (mean age 55 years, 56% women). Cox models were performed with multivariable adjustment for clinical risk factors and physical activity. A total of 708 participants developed incident cardiovascular disease (303 heart failure, 343 coronary heart disease, and 216 stroke events), 48 received a permanent pacemaker, and 1186 died. Baseline heart rate was associated with incident cardiovascular disease (hazard ratio [HR] 1.15 per 1 SD [11 bpm] increase in heart rate, 95% CI 1.07 to 1.24, P=0.0002), particularly heart failure (HR 1.32, 95% CI 1.18 to 1.48, Pheart rate was also associated with higher all‐cause (HR 1.17, 95% CI 1.11 to 1.24, Pheart rate abated or increased. In contrast, individuals with a higher heart rate had a lower risk of requiring permanent pacemaker placement (HR 0.55, 95% CI 0.38 to 0.79, P=0.001). Conclusions Individuals with a higher heart rate are at elevated long‐term risk for cardiovascular events, in particular, heart failure, and all‐cause death. On the other hand, a higher heart rate is associated with a lower risk of future permanent pacemaker implantation. PMID:24811610

  8. Heart Rate Responses to Synthesized Affective Spoken Words

    Directory of Open Access Journals (Sweden)

    Mirja Ilves

    2012-01-01

    Full Text Available The present study investigated the effects of brief synthesized spoken words with emotional content on the ratings of emotions and heart rate responses. Twenty participants' heart rate functioning was measured while they listened to a set of emotionally negative, neutral, and positive words produced by speech synthesizers. At the end of the experiment, ratings of emotional experiences were also collected. The results showed that the ratings of the words were in accordance with their valence. Heart rate deceleration was significantly the strongest and most prolonged to the negative stimuli. The findings are the first suggesting that brief spoken emotionally toned words evoke a similar heart rate response pattern found earlier for more sustained emotional stimuli.

  9. Fetal Heart Rate Pattern Notification Guidelines and Suggested Management Algorithm for Intrapartum Electronic Fetal Heart Rate Monitoring

    OpenAIRE

    Downs, Thomas; Zlomke, Evelyn

    2007-01-01

    Context: Numerous randomized controlled trials have demonstrated limited efficacy of intrapartum fetal heart rate monitoring in improving fetal outcome. A potential reason is the wide variability in clinical decision making seen with its use. Standardizing management of variant intrapartum fetal heart rate tracings may reduce this variability and lead to improvement in fetal outcome.

  10. Predictive value of casual ECG-based resting heart rate compared with resting heart rate obtained from Holter recording

    DEFF Research Database (Denmark)

    Carlson, Nicholas; Dixen, Ulrik; Marott, Jacob L

    2014-01-01

    BACKGROUND: Elevated resting heart rate (RHR) is associated with cardiovascular mortality and morbidity. Assessment of heart rate (HR) from Holter recording may afford a more precise estimate of the effect of RHR on cardiovascular risk, as compared to casual RHR. Comparative analysis was carried ...

  11. Heart rate and heart rate variability during a novel object test and a handling test in young horses

    NARCIS (Netherlands)

    Visser, E.K.; Reenen, van C.G.; Werf, van der J.T.N.; Schilder, M.B.H.; Knaap, J.H.; Barneveld, A.; Blokhuis, H.J.

    2002-01-01

    Forty-one Dutch Warmblood immature horses were used in a study to quantify temperamental traits on the basis of heart rate (HR) and heart rate variability (HRV) measures. Half of the horses received additional training from the age of 5 months onwards; the other half did not. Horses were tested at

  12. Job strain in relation to ambulatory blood pressure, heart rate, and heart rate variability among female nurses

    NARCIS (Netherlands)

    Riese, H.; Doornen, L.J.P. van; Houtman, I.L.D.; Geus, E.J.C. de

    2004-01-01

    Objective. This study examined the effects of exposure to job strain on independent predictors of cardiovascular disease (ambulatory blood pressure, heart rate, and heart rate variability). Methods. The participants comprised a homogeneous group of 159 healthy female nurses [mean age 35.9 (SD 8.5)

  13. Heart rate variability during cycloergometric exercise or judo wrestling eliciting the same heart rate level.

    Science.gov (United States)

    Cottin, François; Durbin, François; Papelier, Yves

    2004-03-01

    This study compared heart rate variability (HRV) in ten male judokas between two types of exercise eliciting the same near-maximal average heart rate (HR): judo wrestling vs. cycloergometric bout. Beat-to-beat RR intervals were recorded during (1) a 4-min judo randori (wrestling); (2) a 4-min cycloergometric exercise eliciting maximal oxygen consumption (VO(2MAX)). Time series were analyzed both by short term Fourier transform (STFT) and Poincaré plot (PP). The main results are as follows. First, despite the fact that the same maximal HR was reached during the two exercises, the spectral energy computed from the judo recordings was significantly higher than that recorded from the cycloergometric exercise. Second, according to the PP index of rapid HRV (SD1), the high-frequency spectral energy (HF) was significantly higher during judo than cycloergometric exercise as well. Third, judo spectra show chaotic harmonics in place of the precise HF peak observed during cycloergometric exercise. Fourth, the respective parts of normalized LFn and HFn are not different between the two exercise modes, suggesting that autonomic control during severe exercise cannot depend on the type of exercise. In conclusion, this study shows that it is possible, according to the observed kind of variability from RR time series, to differentiate between two types of effort: steady-state dynamic exercise or conversely exercise made of both isometric and irregular dynamic efforts (wrestling, collective sports, and others).

  14. Heart rate and heart rate variability modification in chronic insomnia patients.

    Science.gov (United States)

    Farina, Benedetto; Dittoni, Serena; Colicchio, Salvatore; Testani, Elisa; Losurdo, Anna; Gnoni, Valentina; Di Blasi, Chiara; Brunetti, Riccardo; Contardi, Anna; Mazza, Salvatore; Della Marca, Giacomo

    2014-01-01

    Chronic insomnia is highly prevalent in the general population, provoking personal distress and increased risk for psychiatric and medical disorders. Autonomic hyper-arousal could be a pathogenic mechanism of chronic primary insomnia. The aim of this study was to investigate autonomic activity in patients with chronic primary insomnia by means of heart rate variability (HRV) analysis. Eighty-five consecutive patients affected by chronic primary insomnia were enrolled (38 men and 47 women; mean age: 53.2 ± 13.6). Patients were compared with a control group composed of 55 healthy participants matched for age and gender (23 men and 32 women; mean age: 54.2 ± 13.9). Patients underwent an insomnia study protocol that included subjective sleep evaluation, psychometric measures, and home-based polysomnography with evaluation of HRV in wake before sleep, in all sleep stages, and in wake after final awakening. Patients showed modifications of heart rate and HRV parameters, consistent with increased sympathetic activity, while awake before sleep and during Stage-2 non-REM sleep. No significant differences between insomniacs and controls could be detected during slow-wave sleep, REM sleep, and post-sleep wake. These results are consistent with the hypothesis that autonomic hyper-arousal is a major pathogenic mechanism in primary insomnia, and confirm that this condition is associated with an increased cardiovascular risk.

  15. Heart rate, heart rate variability and inflammatory biomarkers among young and healthy adults.

    Science.gov (United States)

    Aeschbacher, Stefanie; Schoen, Tobias; Dörig, Laura; Kreuzmann, Rahel; Neuhauser, Charlotte; Schmidt-Trucksäss, Arno; Probst-Hensch, Nicole M; Risch, Martin; Risch, Lorenz; Conen, David

    2017-02-01

    Heart rate (HR), heart rate variability (HRV), and inflammation are all associated with cardiovascular morbidity and mortality. The aim of this study was to assess potential interrelationships between these parameters in a young and healthy population. Healthy individuals aged 25-41 years were included in a prospective population-based study. All participants underwent 24-h electrocardiography using a validated device. The standard deviation of all normal RR intervals (SDNN) was pre-defined as the main HRV outcome variable. High-sensitivity C-reactive protein (hs-CRP), total leukocyte (LC) count and LC subtypes were obtained from venous blood samples. A total of 2064 participants (47% men, 37 years) were included in this analysis. In multivariable linear regression analyses using SDNN as the outcome variable, β-coefficients (95% confidence intervals) per 1 standard deviation (SD) increase on the log-scale were -0.11 (-0.16; -0.07), p healthy adults, inflammatory parameters were strongly associated with increased HR and decreased HRV, suggesting an important interaction between inflammatory pathways and the autonomic nervous system. Key message Inflammatory biomarkers, such as high-sensitivity C-reactive protein and leukocyte cell count with its subtypes were inversely associated with HRV and positively associated with HR. Our findings suggest important interrelationships between inflammatory pathways and the ANS.

  16. Heart rate differentiates urgency and emergency in hypertensive crisis.

    Science.gov (United States)

    Al Bannay, Rashed; Böhm, Michael; Husain, Aysha

    2013-08-01

    To study the clinical significance of presenting blood pressure parameters and heart rate in patients with hypertensive crisis. In patients admitted with hypertensive crisis between January 2011 and May 2011, demography, mode of presentation, co-morbidities, blood pressure readings, and heart rate at presentation were documented. Further clustering of hypertensive crisis into emergency or urgency was based on the presence or absence of target organ involvement. The relationship between blood pressure parameters, heart rate, and other variables was analyzed. 189 patients in sinus rhythm were enrolled in this pilot study. The rate of hypertensive urgency was 56 %, whereas the rate of hypertensive emergency was 44 %, respectively. Subjects with hypertensive emergency had a higher mean heart rate (93 ± 22.7 bpm) than those with urgency (81 ± 11.5 bpm) (P = 0.015). Women had higher heart rates (92 ± 18.5 bpm) than men (86 ± 17.6 bpm) (P = 0.014). Heart rates below 100 bpm had a specificity of 94 %, classifying patients as hypertensive urgency. Tachycardia had a powerful statistical association with hypertensive left ventricular failure (P pulse pressure, and mean blood pressure relates neither to urgency nor to emergency. Diabetic patients with HBA1c levels of more than 53 mmol/mol had a heart rate of more than 100 bpm (P = 0.015) during hypertensive crisis. Normal heart rate is characteristic of hypertensive urgency. Tachycardia in this setting is an ominous sign and denotes hypertensive complications in particular left ventricular failure. Among diabetics, elevated heart rate is associated with poor glycemic control.

  17. Decreasing Trends in Malnutrition Prevalence Rates Explained by Regular Audits and Feedback

    NARCIS (Netherlands)

    Meijers, J.M.M.; Candel, M.J.M.M.; Schols, J.M.G.A.; van Bokhorst-de van der Schueren, M.A.E.; Halfens, R.J.G.

    2009-01-01

    To our knowledge, no studies have analyzed the influence of annual audit and feedback on the prevalence rates of malnutrition. This study analyzes the trend of malnutrition prevalence rates between 2004 and 2007 and the effects of previous audits and feedback from the annual Dutch National

  18. Adapting workload improves the measurement of heart rate recovery.

    Science.gov (United States)

    Lamberts, R P; Maskell, S; Borresen, J; Lambert, M I

    2011-09-01

    Heart rate after a standardized test varies with a change in training status, possibly compromising the accuracy of measuring changes in heart rate recovery (HRR). The aim of this study was to determine if a change in the exercise intensity would result in a change in heart rate recovery and/or the accuracy of the heart rate recovery measurement. 31 subjects performed 4 submaximal running tests (HIMS). Based on the heart rate after the first HIMS, subjects either completed 4 identical HIMS (SAME (n=9)), 2 standard and 2 faster HIMS (FASTER (n=10)) or 2 standard and 2 slower HIMS (SLOWER (n=12)). Although no changes in heart rate recovery were found when the HIMS protocol was adapted, lower coefficients of variation (CV) and typical errors of measurement (TEM) were found in the SLOWER (CV: 11 ± 7 to 5 ± 3% ( P=0.025)), TEM: 6 to 3 beats and FASTER group (CV: 11 ± 7 to 4 ± 3% ( P=0.048), TEM: 7 to 3 beats). To ensure the highest level of sensitivity in detecting meaningful changes in HRR over time, submaximal testing protocols should target exercise intensities ranging in-between 86-93% of heart rate maximum. © Georg Thieme Verlag KG Stuttgart · New York.

  19. Fetal Heart Rate Monitoring from Phonocardiograph Signal Using Repetition Frequency of Heart Sounds

    Directory of Open Access Journals (Sweden)

    Hong Tang

    2016-01-01

    Full Text Available As a passive, harmless, and low-cost diagnosis tool, fetal heart rate (FHR monitoring based on fetal phonocardiography (fPCG signal is alternative to ultrasonographic cardiotocography. Previous fPCG-based methods commonly relied on the time difference of detected heart sound bursts. However, the performance is unavoidable to degrade due to missed heart sounds in very low signal-to-noise ratio environments. This paper proposes a FHR monitoring method using repetition frequency of heart sounds. The proposed method can track time-varying heart rate without both heart sound burst identification and denoising. The average accuracy rate comparison to benchmark is 88.3% as the SNR ranges from −4.4 dB to −26.7 dB.

  20. Effect of Selective Heart Rate Slowing in Heart Failure With Preserved Ejection Fraction.

    Science.gov (United States)

    Pal, Nikhil; Sivaswamy, Nadiya; Mahmod, Masliza; Yavari, Arash; Rudd, Amelia; Singh, Satnam; Dawson, Dana K; Francis, Jane M; Dwight, Jeremy S; Watkins, Hugh; Neubauer, Stefan; Frenneaux, Michael; Ashrafian, Houman

    2015-11-03

    Heart failure with preserved ejection fraction (HFpEF) is associated with significant morbidity and mortality but is currently refractory to therapy. Despite limited evidence, heart rate reduction has been advocated, on the basis of physiological considerations, as a therapeutic strategy in HFpEF. We tested the hypothesis that heart rate reduction improves exercise capacity in HFpEF. We conducted a randomized, crossover study comparing selective heart rate reduction with the If blocker ivabradine at 7.5 mg twice daily versus placebo for 2 weeks each in 22 symptomatic patients with HFpEF who had objective evidence of exercise limitation (peak oxygen consumption at maximal exercise [o2 peak] heart rate compared with placebo in the HFpEF (107 versus 129 bpm; Pheart rate reduction with ivabradine for improving symptoms in a HFpEF population characterized by exercise limitation. URL: http://www.clinicaltrials.gov. Unique identifier: NCT02354573. © 2015 The Authors.

  1. Assesment of Autonomic Function in Metabolic Syndrome using Combination Heart Rate Variability and Heart Rate Turbulence

    Directory of Open Access Journals (Sweden)

    Gülay Aydın

    2013-12-01

    Full Text Available INTRODUCTION: Metabolic syndrome (MetS is described as a group of various abnormal metabolic risk factors such as obesity, dyslipidemia, increased blood pressure, increased plasma glucose levels, prothrombotic condition and proinflammatory state. These parameters are related to decreased parasympathetic and increased sympathetic activity. We aimed to evaluate autonomic function using a combination with heart rate variability (HRV and heart rate turbulence (HRT in metabolic syndrome to compare non-metabolic syndrome(non-MetS. METHODS: We selected consecutive 50 patients with MetS and 50 patients with healthy non-MetS individuals. All patients underwent 24 hours holter monitoring to evaluate HRT and HRV parameters. RESULTS: Age of patients was not different in two groups. Mean age of MetS patients was 57,50±12,13 and 54,6±10,25 in non- MetS individuals. Sex of patients was non different in MetS compared to non-MetS (37 female and 13 male vs. 22 female, 28 male p<0,05 respectively. SDNN and RMSSD was lower in MetS compared to those without MetS (131,96±49,12 vs 179,59±85,83 p=0,03 and 78,64±35,22 vs 112,73±81,24 p=0,08 respectively. SDANN, pNN50,Mean RR, mean heart rate, count of ventricular premature complex(VPC were not different between two groups. Turbulence Slope(TS was not different in two groups. Turbulence Onset(TO was higher in MetS compared to non-MetS (2,01±15,29 and -6,21±13,5 p=0,005. DISCUSSION AND CONCLUSION: We showed that autonomic function in MetS was impaired using a combination with HRT and HRV. These patients should be followed closely for adverse cardiovascular outcome especially including cardiac arrhythmia.

  2. Electronic fetal heart rate monitoring: where are we now?

    Science.gov (United States)

    Chez, Bonnie Flood; Baird, Suzanne McMurtry

    2011-01-01

    Electronic fetal heart rate monitoring (EFM) continues to be the primary method utilized for fetal assessment in the United States. Standardization of nomenclature associated with this perinatal technology has evolved over the past 40 years such that the current nomenclature recommended by the National Institute of Child Health and Human Development (NICHD) has been adopted by professional perinatal organizations as the agreed-upon method for professional communication and documentation. Current research continues to focus on the optimal management of intrapartum fetal heart rate tracings. The clinical controversies and challenges related to electronic fetal heart rate monitoring continue to evolve.

  3. Heart rate, heart rate variability, and arrhythmias in dogs with myxomatous mitral valve disease

    DEFF Research Database (Denmark)

    Rasmussen, Caroline Elisabeth; Falk, Bo Torkel; Zois, Nora Elisabeth

    2012-01-01

    Autonomic modulation of heart rhythm is thought to influence the pathophysiology of myxomatous mitral valve disease (MMVD).......Autonomic modulation of heart rhythm is thought to influence the pathophysiology of myxomatous mitral valve disease (MMVD)....

  4. Behaviour, heart rate, and heart rate variability in pigs exposed to novelty

    Directory of Open Access Journals (Sweden)

    Manja Zupan

    2016-03-01

    Full Text Available ABSTRACT In the present study, we investigated behavioural responses and determined parameters of heart rate variability (HRV to elucidate a relative activation of autonomic nervous system (ANS during baseline (10 min and in response to potentially stressful situations (10 min in two pig breeds and sexes. Gilts (n = 21 and barrows (n = 9 of the Landrace × Yorkshire (LY; n = 15 and Landrace/Yorkshire × Landrace/Duroc (LYLD; n = 15 breeds were subjected to a novel object test (NOT and a novel arena test (NAT. Basal ANS state differed in pigs across breeds but not sexes. Landrace × Yorkshire pigs had a significantly lower basal heart rate (HR and low-frequency band (LF with a higher root mean square of successive interbeat intervals (RMSSD and high-frequency band (HF than LYLD pigs. In the NOT, despite having similar cardiac responses, gilts had a longer duration of contact with a novel object, higher lying and standing duration, and a lower duration of walking compared with barrows. In the NAT, we found similar behaviour across sexes but a different degree of ANS state, with barrows having a significantly higher increase in LF/HF (power of the low frequency component divided by the power of the high-frequency band compared with gilts. Landrace/Yorkshire × Landrace/Duroc pigs showed longer duration of contact with a novel object in the NOT accompanied by less lying and standing than LY pigs in both tests. No difference in ANS activation between breeds was found in the NOT. In the NAT, HR increased more from baseline to testing in LY pigs than in LYLD pigs. There is a complex and often contradictory nature of relationships between behaviour and cardiac responses to novelty in pigs of different breeds and sexes.

  5. Guided imagery, anxiety, heart rate, and heart rate variability during centrifuge training.

    Science.gov (United States)

    Jing, Xiaolu; Wu, Ping; Liu, Fang; Wu, Bin; Miao, Danmin

    2011-02-01

    Centrifuge training is an important method of improving the hypergravity tolerance of pilots, cosmonauts, and Chinese astronauts. However, the concomitants of tension or anxiety often impede training. Guided imagery (GI), a mind-body relaxation technique, provides a behavioral and cognitive means whereby individuals are able to exert control over the focus of attention. This study aims to investigate the immediate effects of GI for reducing stress in centrifuge training. There were 12 healthy young men who were randomly assigned to a GI group or music group. We measured changes in heart rate during centrifuge training, in heart rate variability before and after centrifuge training, and also evaluated relaxation and anxiety in three phases: before intervention, after intervention, and following centrifuge training. The change in the pattern of anxiety was different in the two groups over the three phases. Anxiety (measured by State Anxiety Inventory) in the GI group changed from 31.7 +/- 5.9 to 26.8 +/- 2.6 and 27.8 +/- 4.1, whereas for the music group this changed from 32.2 +/- 7.6 to 31.2 +/- 8.3 and 26.8 +/- 6.8. During centrifuge training, the maximal HR for the GI group (101.2 +/- 8.8) was lower than that of the music group (123.0 +/- 19.1). In addition GI showed a decrease in low frequency (LF, 0.04-0.15 Hz) components and an increase in high frequency (HF, 0.15-0.4 Hz) components before and after centrifuge training. GI was capable of decreasing tension, anxiety, and sympathetic nervous system activity pre- or post-centrifugation.

  6. Comparison of Polar M600 Optical Heart Rate and ECG Heart Rate during Exercise.

    Science.gov (United States)

    Horton, John F; Stergiou, Pro; Fung, Tak S; Katz, Larry

    2017-12-01

    The purpose of this study was to evaluate the accuracy of the Polar M600 optical heart rate (OHR) sensor compared with ECG heart rate (HR) measurement during various physical activities. Thirty-six subjects participated in a continuous 76-min testing session, which included rest, cycling warm-up, cycling intervals, circuit weight training, treadmill intervals, and recovery. HR was measured using a three-lead ECG configuration and a Polar M600 Sport Watch on the left wrist. Statistical analyses included OHR percent accuracy, mean difference, mean absolute error, Bland-Altman plots, and a repeated-measures generalized estimating equation design. OHR percent accuracy was calculated as the percentage of occurrences where OHR measurement was within and including ±5 bpm from the ECG HR value. Of the four exercise phases performed, the highest OHR percent accuracy was found during cycle intervals (91.8%), and the lowest OHR percent accuracy occurred during circuit weight training (34.5%). OHR percent accuracy improved steadily within exercise transitions during cycle intervals to a maximum of 98.5% and during treadmill intervals to a maximum of 89.0%. Lags in HR calculated by the Polar M600 OHR sensor existed in comparison to ECG HR, when exercise intensity changed until steady state occurred. There was a tendency for OHR underestimation during intensity increases and overestimation during intensity decreases. No statistically significant interaction effect with device was found in this sample on the basis of sex, body mass index, V˙O2max, skin type, or wrist size. The Polar M600 was accurate during periods of steady-state cycling, walking, jogging, and running, but less accurate during some exercise intensity changes, which may be attributed to factors related to total peripheral resistance changes and pulse pressure.

  7. Increased heart rate variability but normal resting metabolic rate in hypocretin/orexin-deficient human narcolepsy.

    NARCIS (Netherlands)

    Fronczek, R.; Overeem, S.; Reijntjes, R.; Lammers, G.J.; Dijk, J.G.M.; Pijl, H.

    2008-01-01

    STUDY OBJECTIVES: We investigated autonomic balance and resting metabolic rate to explore their possible involvement in obesity in hypocretin/orexin-deficient narcoleptic subjects. METHODS: Resting metabolic rate (using indirect calorimetry) and variability in heart rate and blood pressure were

  8. Summary The effect of pregnancy on the heart rate, respiratory rate ...

    African Journals Online (AJOL)

    Summary. The effect of pregnancy on the heart rate, respiratory rate,. QRS axis and QRS complex duration of the ECG was investigated in 41 pregnant compared to 39 non pregnant age and height matched Nigerian subjects. Results obtained show that pregnancy had no significant effect (p>0.05) on heart rate, respiratory ...

  9. Arduino-based noise robust online heart-rate detection.

    Science.gov (United States)

    Das, Sangita; Pal, Saurabh; Mitra, Madhuchhanda

    2017-04-01

    This paper introduces a noise robust real time heart rate detection system from electrocardiogram (ECG) data. An online data acquisition system is developed to collect ECG signals from human subjects. Heart rate is detected using window-based autocorrelation peak localisation technique. A low-cost Arduino UNO board is used to implement the complete automated process. The performance of the system is compared with PC-based heart rate detection technique. Accuracy of the system is validated through simulated noisy ECG data with various levels of signal to noise ratio (SNR). The mean percentage error of detected heart rate is found to be 0.72% for the noisy database with five different noise levels.

  10. Signal processing methodologies for an acoustic fetal heart rate monitor

    Science.gov (United States)

    Pretlow, Robert A., III; Stoughton, John W.

    1992-01-01

    Research and development is presented of real time signal processing methodologies for the detection of fetal heart tones within a noise-contaminated signal from a passive acoustic sensor. A linear predictor algorithm is utilized for detection of the heart tone event and additional processing derives heart rate. The linear predictor is adaptively 'trained' in a least mean square error sense on generic fetal heart tones recorded from patients. A real time monitor system is described which outputs to a strip chart recorder for plotting the time history of the fetal heart rate. The system is validated in the context of the fetal nonstress test. Comparisons are made with ultrasonic nonstress tests on a series of patients. Comparative data provides favorable indications of the feasibility of the acoustic monitor for clinical use.

  11. Prognostic significance of heart rate turbulence parameters in patients with chronic heart failure

    OpenAIRE

    Yin, De-Chun; Wang, Zhao-Jun; Guo, Shuai; Xie, Hong-Yu; Sun, Lin; Feng, Wei; Qiu, Wei; Qu, Xiu-Fen

    2014-01-01

    Background This study is aimed to evaluate the clinical significance of heart rate turbulence (HRT) parameters in predicting the prognosis in patients with chronic heart failure (CHF). Methods From June 2011 to December 2012, a total of 104 CHF patients and 30 healthy controls were enrolled in this study. We obtained a 24-hour Holter ECG recording to assess the HRT parameters, included turbulence onset (TO), turbulence slope (TS), standard deviation of N-N intervals (SDNN), and resting heart ...

  12. Disentangling Respiratory Sinus Arrhythmia in Heart Rate Variability Records

    OpenAIRE

    Topçu, Çağdaş; Frühwirth, Matthias; Moser, Maximilian; Rosenblum, Michael; Pikovsky, Arkady

    2018-01-01

    Different measures of heart rate variability and particularly of respiratory sinus arrhythmia are widely used in research and clinical applications. Inspired by the ideas from the theory of coupled oscillators, we use simultaneous measurements of respiratory and cardiac activity to perform a nonlinear decomposition of the heart rate variability into the respiratory-related component and the rest. We suggest to exploit the technique as a universal preprocessing tool, both for the analysis of r...

  13. Accuracy of Heart Rate Watches: Implications for Weight Management.

    Directory of Open Access Journals (Sweden)

    Matthew P Wallen

    Full Text Available Wrist-worn monitors claim to provide accurate measures of heart rate and energy expenditure. People wishing to lose weight use these devices to monitor energy balance, however the accuracy of these devices to measure such parameters has not been established.To determine the accuracy of four wrist-worn devices (Apple Watch, Fitbit Charge HR, Samsung Gear S and Mio Alpha to measure heart rate and energy expenditure at rest and during exercise.Twenty-two healthy volunteers (50% female; aged 24 ± 5.6 years completed ~1-hr protocols involving supine and seated rest, walking and running on a treadmill and cycling on an ergometer. Data from the devices collected during the protocol were compared with reference methods: electrocardiography (heart rate and indirect calorimetry (energy expenditure.None of the devices performed significantly better overall, however heart rate was consistently more accurate than energy expenditure across all four devices. Correlations between the devices and reference methods were moderate to strong for heart rate (0.67-0.95 [0.35 to 0.98] and weak to strong for energy expenditure (0.16-0.86 [-0.25 to 0.95]. All devices underestimated both outcomes compared to reference methods. The percentage error for heart rate was small across the devices (range: 1-9% but greater for energy expenditure (9-43%. Similarly, limits of agreement were considerably narrower for heart rate (ranging from -27.3 to 13.1 bpm than energy expenditure (ranging from -266.7 to 65.7 kcals across devices.These devices accurately measure heart rate. However, estimates of energy expenditure are poor and would have implications for people using these devices for weight loss.

  14. Heart Rate at Hospital Discharge in Patients With Heart Failure Is Associated With Mortality and Rehospitalization

    Science.gov (United States)

    Laskey, Warren K.; Alomari, Ihab; Cox, Margueritte; Schulte, Phillip J.; Zhao, Xin; Hernandez, Adrian F.; Heidenreich, Paul A.; Eapen, Zubin J.; Yancy, Clyde; Bhatt, Deepak L.; Fonarow, Gregg C.

    2015-01-01

    Background Whether heart rate upon discharge following hospitalization for heart failure is associated with long‐term adverse outcomes and whether this association differs between patients with sinus rhythm (SR) and atrial fibrillation (AF) have not been well studied. Methods and Results We conducted a retrospective cohort study from clinical registry data linked to Medicare claims for 46 217 patients participating in Get With The Guidelines®–Heart Failure. Cox proportional‐hazards models were used to estimate the association between discharge heart rate and all‐cause mortality, all‐cause readmission, and the composite outcome of mortality/readmission through 1 year. For SR and AF patients with heart rate ≥75, the association between heart rate and mortality (expressed as hazard ratio [HR] per 10 beats‐per‐minute increment) was significant at 0 to 30 days (SR: HR 1.30, 95% CI 1.22 to 1.39; AF: HR 1.23, 95% CI 1.16 to 1.29) and 31 to 365 days (SR: HR 1.15, 95% CI 1.12 to 1.20; AF: HR 1.05, 95% CI 1.01 to 1.08). Similar associations between heart rate and all‐cause readmission and the composite outcome were obtained for SR and AF patients from 0 to 30 days but only in the composite outcome for SR patients over the longer term. The HR from 0 to 30 days exceeded that from 31 to 365 days for both SR and AF patients. At heart rates heart failure, higher discharge heart rate was associated with increased risks of death and rehospitalization, with higher risk in the first 30 days and for SR compared with AF. PMID:25904590

  15. Probability of detection of clinical seizures using heart rate changes.

    Science.gov (United States)

    Osorio, Ivan; Manly, B F J

    2015-08-01

    Heart rate-based seizure detection is a viable complement or alternative to ECoG/EEG. This study investigates the role of various biological factors on the probability of clinical seizure detection using heart rate. Regression models were applied to 266 clinical seizures recorded from 72 subjects to investigate if factors such as age, gender, years with epilepsy, etiology, seizure site origin, seizure class, and data collection centers, among others, shape the probability of EKG-based seizure detection. Clinical seizure detection probability based on heart rate changes, is significantly (pprobability of detecting clinical seizures (>0.8 in the majority of subjects) using heart rate is highest for complex partial seizures, increases with a patient's years with epilepsy, is lower for females than for males and is unrelated to the side of hemisphere origin. Clinical seizure detection probability using heart rate is multi-factorially dependent and sufficiently high (>0.8) in most cases to be clinically useful. Knowledge of the role that these factors play in shaping said probability will enhance its applicability and usefulness. Heart rate is a reliable and practical signal for extra-cerebral detection of clinical seizures originating from or spreading to central autonomic network structures. Copyright © 2015 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

  16. Power flow control based solely on slow feedback loop for heart pump applications.

    Science.gov (United States)

    Wang, Bob; Hu, Aiguo Patrick; Budgett, David

    2012-06-01

    This paper proposes a new control method for regulating power flow via transcutaneous energy transfer (TET) for implantable heart pumps. Previous work on power flow controller requires a fast feedback loop that needs additional switching devices and resonant capacitors to be added to the primary converter. The proposed power flow controller eliminates these additional components, and it relies solely on a slow feedback loop to directly drive the primary converter to meet the heart pump power demand and ensure zero voltage switching. A controlled change in switching frequency varies the resonant tank shorting period of a current-fed push-pull resonant converter, thus changing the magnitude of the primary resonant voltage, as well as the tuning between primary and secondary resonant tanks. The proposed controller has been implemented successfully using an analogue circuit and has reached an end-to-end power efficiency of 79.6% at 10 W with a switching frequency regulation range of 149.3 kHz to 182.2 kHz.

  17. Reliability and robustness of feedback-evoked brain-heart coupling after placebo, dopamine, and noradrenaline challenge.

    Science.gov (United States)

    Lueckel, Maximilian; Panitz, Christian; Nater, Urs M; Mueller, Erik M

    2018-01-27

    External and internal performance feedback triggers not only neural but also cardiac modulations, suggesting communication between brain and heart during feedback processing. Using Cardio-Electroencephalographic Covariance Tracing (CECT), it has accordingly been shown that feedback-evoked centromedial single-trial EEG at the P300 latency intraindividually predicts subsequent changes in heart period - the so called N300H phenomenon. While previous findings suggest that the N300H depends on serotonin, its relationship to central dopamine and noradrenaline is currently unknown. Here, we tested (1) the psychometric properties of this CECT-based component and (2) its putative catecholaminergic mechanisms. N = 54 healthy male participants received either a α2-adrenoceptor antagonist (yohimbine, 10 mg; n = 18), D2-dopamine-receptor antagonist (sulpiride, 200 mg; n = 18), or a placebo (n = 18). Afterwards, they performed a gambling task with feedback after each trial, while EEG and ECG were recorded. Feedback successfully evoked a significant N300H both across all 54 participants and within each substance group. Importantly, we show that N300H can be reliably measured in a priori defined time windows with as few as 240 feedback trials and is relatively unaffected when removing extreme single-trial values. However, we could not find any significant substance effects on N300H magnitude as well as on univariate feedback-related measures (FRN, P300, heart period). Altogether, the N300H component proves as a robust and reliable marker of cortico-cardiac coupling evoked by feedback. Furthermore, these findings suggest a subordinate role of catecholamines (i.e., noradrenaline and dopamine) and sympathetic pathways in feedback-evoked brain-heart communication as measured with N300H. Copyright © 2017. Published by Elsevier B.V.

  18. The effect of performance feedback on drivers' hazard perception ability and self-ratings.

    Science.gov (United States)

    Horswill, Mark S; Garth, Megan; Hill, Andrew; Watson, Marcus O

    2017-04-01

    Drivers' hazard perception ability has been found to predict crash risk, and novice drivers appear to be particularly poor at this skill. This competency appears to develop only slowly with experience, and this could partially be a result of poor quality performance feedback. We report an experiment in which we provided high-quality artificial feedback on individual drivers' performance in a validated video-based hazard perception test via either: (1) a graph-based comparison of hazard perception response times between the test-taker, the average driver, and an expert driver; (2) a video-based comparison between the same groups; or (3) both. All three types of feedback resulted in both an improvement in hazard perception performance and a reduction in self-rated hazard perception skill, compared with a no-feedback control group. Video-based and graph-based feedback combined resulted in a greater improvement in hazard perception performance than either of the individual components, which did not differ from one another. All three types of feedback eliminated participants' self-enhancement bias for hazard perception skill. Participants judged both interventions involving video feedback to be significantly more likely to improve their real-world driving than the no feedback control group. While all three forms of feedback had some value, the combined video and graph feedback intervention appeared to be the most effective across all outcome measures. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Exercise heart rate monitors for anxiety treatment in a rural primary care setting: a pilot study.

    Science.gov (United States)

    Houser, Melissa Marotta; Rosen, Lee; Seagrave, Martha P; Grabowski, Don; Matthew, John D; Craig, William A P

    2013-10-01

    Rural patients with anxiety often lack access to traditional biofeedback modalities. Exercise heart rate monitors (HRMs) are tools used in the fitness industry to provide athletes with feedback on heart rate and regulatory breathing strategies. HRMs are inexpensive, discrete, and publicly accessible. This randomized controlled pilot study explored whether use of HRMs for biofeedback during guided mindfulness, diaphragmatic breathing, and progressive muscle relaxation techniques could facilitate anxiety reduction as compared to these techniques alone. Fifty-three rural anxiety patients were randomized to HRM or control groups for four weekly 20-minute, scripted sessions with a non-behaviorist wherein they practiced these techniques; the HRM group received feedback on their heart rate response. The HRM group had significantly greater improvement in state anxiety (State-Trait Anxiety Inventory) and self-efficacy (General Self Efficacy Scale), and a greater percentage of the group indicated that they "felt in control of their anxiety." This pilot study demonstrates that this novel, inexpensive, and accessible tool may be a useful clinical intervention for anxiety and can be easily incorporated by both behaviorists and non-behaviorist primary care clinicians into individual or group biofeedback treatment for patients with anxiety. This tool has additional potential for patients to use for anxiety self-management. Further study with a larger sample and blinded design is warranted.

  20. Inadequate control of heart rate in patients with stable angina: results from the European heart survey.

    NARCIS (Netherlands)

    Daly, C.A.; Clemens, F.; Sendon, J.L.; Tavazzi, L.; Boersma, E.; Danchin, N.; Delahaye, F.; Gitt, A.; Julian, D.; Mulcahy, D.; Ruzyllo, W.; Thygesen, K.; Verheugt, F.W.A.; Fox, K.M.

    2010-01-01

    AIMS: To examine resting heart rate (HR) in a population presenting with stable angina in relation to prior and subsequent pharmacological treatment, comorbid conditions and clinical outcome. METHODS AND RESULTS: The European Heart Survey was a prospective, observational, cohort study of 3779

  1. Gene expression of stretch-activated channels and mechanoelectric feedback in the heart.

    Science.gov (United States)

    Kelly, D; Mackenzie, L; Hunter, P; Smaill, B; Saint, D A

    2006-07-01

    1. Mechanoelectric feedback (MEF) in the heart is the process by which mechanical forces on the myocardium can change its electrical properties. Mechanoelectric feedback has been demonstrated in many animal models, ranging from isolated cells, through isolated hearts to whole animals. In humans, MEF has been demonstrated directly in both the atria and the ventricles. It seems likely that MEF provides either the trigger or the substrate for some types of clinically important arrhythmias. 2. Mechanoelectric feedback may arise because of the presence of stretch-sensitive (or mechano-sensitive) ion channels in the cell membrane of the cardiac myocytes. Two types have been demonstrated: (i) a non-specific cation channel (stretch-activated channel (SAC); conductance of approximately 25 pS); and (ii) a potassium channel with a conductance of approximately 100 pS. The gene coding for the SAC has not yet been identified. The gene for the potassium channel is likely to be TREK, a member of the tandem pore potassium channel gene family. We have recorded stretch-sensitive potassium channels in rat isolated myocytes that have the properties of TREK channels expressed in heterologous systems. 3. It has been shown that TREK mRNA is expressed heterogeneously in the rat ventricular wall, with 17-fold more expression in endocardial compared with epicardial cells. This difference is reflected in the TREK currents recorded from endocardial and epicardial cells using whole-cell patch-clamp techniques, although the difference in current density was less pronounced (approximately threefold). Consistent with this, we show here that when the ventricle is stretched by inflation of an intraventricular balloon in a Langendorff perfused rat isolated heart, action potential shortening was more pronounced in the endocardium (30% shortening at 40 mmHg) compared with that in the epicardium (10% shortening at the same pressure). 4. Computer models of the mechanics of the (pig) heart show pronounced

  2. Evaluation of the metabolic rate based on the recording of the heart rate

    OpenAIRE

    MALCHAIRE, Jacques; ALFANO, Francesca Romana d?AMBROSIO; PALELLA, Boris Igor

    2017-01-01

    The assessment of harsh working conditions requires a correct evaluation of the metabolic rate. This paper revises the basis described in the ISO 8996 standard for the evaluation of the metabolic rate at a work station from the recording of the heart rate of a worker during a representative period of time. From a review of the literature, formulas different from those given in the standard are proposed to estimate the maximum working capacity, the maximum heart rate, the heart rate and the me...

  3. Heart rate variability and heart rate turbulence in mild-to-moderate aortic stenosis.

    Science.gov (United States)

    Arslan, Ugur; Ozdemir, Murat; Kocaman, Sinan Altan; Balcioglu, Serhat; Cemri, Mustafa; Cengel, Atiye

    2008-12-01

    To study heart rate (HR) variability and HR turbulence parameters in mild-to-moderate aortic stenosis (AS) and to disclose whether any relationship exists between these parameters and echocardiographic findings. Forty-three asymptomatic patients with mild-to-moderate AS (AS group) were studied. Echocardiographic parameters and HR variability and HR turbulence indices obtained over 24 Holter ECG recordings were compared with those of an age and sex matched control population free of cardiovascular disease. Correlation between echocardiographic findings and HR variability and HR turbulence indices was also studied in the AS group. All HR variability parameters except mean RR interval, RMSSD, and pNN50 and one HR turbulence parameter, turbulence onset, were significantly disturbed in the AS group. Echocardiographic findings of diastolic dysfunction had significant correlations with HR variability and HR turbulence parameters in AS patients. Symphatovagal imbalance as shown by disturbed HR variability and HR turbulence parameters was demonstrated for the first time in patients with mild-to-moderate AS. This imbalance, which was shown to be correlated with echocardiographic findings of diastolic dysfunction, may lead to arrhythmic complications in this seemingly low-risk patient population.

  4. Quantification of fetal heart rate regularity using symbolic dynamics

    Science.gov (United States)

    van Leeuwen, P.; Cysarz, D.; Lange, S.; Geue, D.; Groenemeyer, D.

    2007-03-01

    Fetal heart rate complexity was examined on the basis of RR interval time series obtained in the second and third trimester of pregnancy. In each fetal RR interval time series, short term beat-to-beat heart rate changes were coded in 8bit binary sequences. Redundancies of the 28 different binary patterns were reduced by two different procedures. The complexity of these sequences was quantified using the approximate entropy (ApEn), resulting in discrete ApEn values which were used for classifying the sequences into 17 pattern sets. Also, the sequences were grouped into 20 pattern classes with respect to identity after rotation or inversion of the binary value. There was a specific, nonuniform distribution of the sequences in the pattern sets and this differed from the distribution found in surrogate data. In the course of gestation, the number of sequences increased in seven pattern sets, decreased in four and remained unchanged in six. Sequences that occurred less often over time, both regular and irregular, were characterized by patterns reflecting frequent beat-to-beat reversals in heart rate. They were also predominant in the surrogate data, suggesting that these patterns are associated with stochastic heart beat trains. Sequences that occurred more frequently over time were relatively rare in the surrogate data. Some of these sequences had a high degree of regularity and corresponded to prolonged heart rate accelerations or decelerations which may be associated with directed fetal activity or movement or baroreflex activity. Application of the pattern classes revealed that those sequences with a high degree of irregularity correspond to heart rate patterns resulting from complex physiological activity such as fetal breathing movements. The results suggest that the development of the autonomic nervous system and the emergence of fetal behavioral states lead to increases in not only irregular but also regular heart rate patterns. Using symbolic dynamics to

  5. HEART-RATE-VARIABILITY IN LEFT-VENTRICULAR DYSFUNCTION AND HEART-FAILURE - EFFECTS AND IMPLICATIONS OF DRUG-TREATMENT

    NARCIS (Netherlands)

    TUININGA, YS; VANVELDHUISEN, DJ; BROUWER, J; HAAKSMA, J; CRIJNS, HJGM; MANINTVELD, AJ; LIE, KI

    1994-01-01

    Objective-To review the importance of heart rate variability analysis in left ventricular dysfunction and heart failure and to assess the effects of drug treatment. In patients with left: ventricular dysfunction or heart failure, a low heart rate variability is a strong predictor of a low

  6. Cognitive strategies, perception of effort and heart rate in endurance ...

    African Journals Online (AJOL)

    A light-weight micro-cassette recorder was used to document the subjects' verbalised thoughts while training. Effort was measured by the rate of perceived exertion (RPE) at the completion of each ride, and through the recording of heart rate every 60 seconds. A cycling-specific sub-category of thought ";equipment ...

  7. The Use of Heart Rate Monitors in Physical Education

    Science.gov (United States)

    Nichols, Randall; Davis, Kathryn L.; McCord, Tim; Schmidt, Dave; Slezak, Alex M.

    2009-01-01

    The ever-rising rate of obesity and the need for increased physical activity for young children is well documented. Data suggests that today's youth are not participating in enough quality health-enhancing physical activity either in or outside of school. Heart rate monitors have been used by adult exercisers for many years to monitor and assess…

  8. Heart rate-based lactate minimum test: a reproducible method.

    NARCIS (Netherlands)

    Strupler, M.; Muller, G.; Perret, C.

    2009-01-01

    OBJECTIVE: To find the individual intensity for aerobic endurance training, the lactate minimum test (LMT) seems to be a promising method. LMTs described in the literature consist of speed or work rate-based protocols, but for training prescription in daily practice mostly heart rate is used. The

  9. Impact of training load on the heart rate of horses

    Directory of Open Access Journals (Sweden)

    Eva Mlyneková

    2016-12-01

    Full Text Available In our work, we analyzed the effect of training load on the heart rate of horses in a simulated load by the loading regulator for horse motion Horse Gym 2000. In the experiment were observed 8 Slovak Warmblood horses (3 mares, 4 geldings, 1 stallion aged 6-10 years. The experiment was divided into two parts after three weeks. The speed of the tested horses was 4.9 km/h in the first part of experiment, in the second part was the speed 5.2 km/h with a gradual uphill up to 7 %. The tested horses achieved during the experiment an average heart rate level below 70 beats a minute, which is a light load. The maximum values of heart rate were recorded at 120 to 147 beats/min. Differences between tested horses in the values of heart rate were not statistically significant. After three weeks we recorded in the values of average and maximum heart rate onset of bradycardia, which is documented the adaptation of body to the specified load.

  10. Steep Trendelenburg position during robotic sacrocolpopexy and heart rate variability.

    Science.gov (United States)

    Lowenstein, Lior; Mustafa, Mona; Burke, Yechiel Z; Mustafa, Susana; Segal, Dror; Weissman, Amir

    2014-07-01

    The objective of this study was to evaluate heart rate variability and hemodynamic parameters following steep Trendelenburg positioning during robotic sacrocolpopexy. For 19 women, median age 57 (range: 45-72), blood pressure and ECG were recorded during surgery. From the ECG signals interbeat intervals were used to assess heart rate variability, analyzed in time and frequency domains using the Fast Fourier transform. The low frequency and high frequency spectral bands were used to assess sympathetic and parasympathetic pathways respectively. All women underwent robotic supracervical hysterectomy and sacrocolpopexy. A statistically significant decrease in the mean values of the low-frequency and high-frequency spectral bands, representing sympathetic and parasympathetic activity, respectively were demonstrated 5min following Trendelenburg positioning of the patients (from 3.6±1.4 to 2.9±0.8ms(2)/Hz, and from 3.5±1.4 to 2.9±1ms(2)/Hz, Pchanges correlated with a mean 20% decrease in heart rate, which lasted for 30min, and with a second drop in sympathetic and parasympathetic activity and heart rate, commencing 2h from the start of surgery, and lasting until the end of the operation. Steep Tredelenburg positioning during robotic urogynecology surgery results in significant changes in the autonomic nervous system modulation of heart rate variability and in other hemodynamic parameters. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  11. Heart rate measurement based on face video sequence

    Science.gov (United States)

    Xu, Fang; Zhou, Qin-Wu; Wu, Peng; Chen, Xing; Yang, Xiaofeng; Yan, Hong-jian

    2015-03-01

    This paper proposes a new non-contact heart rate measurement method based on photoplethysmography (PPG) theory. With this method we can measure heart rate remotely with a camera and ambient light. We collected video sequences of subjects, and detected remote PPG signals through video sequences. Remote PPG signals were analyzed with two methods, Blind Source Separation Technology (BSST) and Cross Spectral Power Technology (CSPT). BSST is a commonly used method, and CSPT is used for the first time in the study of remote PPG signals in this paper. Both of the methods can acquire heart rate, but compared with BSST, CSPT has clearer physical meaning, and the computational complexity of CSPT is lower than that of BSST. Our work shows that heart rates detected by CSPT method have good consistency with the heart rates measured by a finger clip oximeter. With good accuracy and low computational complexity, the CSPT method has a good prospect for the application in the field of home medical devices and mobile health devices.

  12. Heart rate detection from an electronic weighing scale.

    Science.gov (United States)

    González-Landaeta, R; Casas, O; Pallàs-Areny, R

    2007-01-01

    We propose a novel technique for heart rate detection on a subject that stands on a common electronic weighing scale. The detection relies on sensing force variations related to the blood acceleration in the aorta, works even if wearing footwear, and does not require any sensors attached to the body. We have applied our method to three different weighing scales, and estimated whether their sensitivity and frequency response suited heart rate detection. Scale sensitivities were from 490 nV/V/N to 1670 nV/V/N, all had an underdamped transient response and their dynamic gain error was below 19% at 10 Hz, which are acceptable values for heart rate estimation. We also designed a pulse detection system based on off-the-shelf integrated circuits, whose gain was about 70x10(3) and able to sense force variations about 240 mN. The signal-to-noise ratio (SNR) of the main peaks of the pulse signal detected was higher than 48 dB, which is large enough to estimate the heart rate by simple signal processing methods. To validate the method, the ECG and the force signal were simultaneously recorded on 12 volunteers. The maximal error obtained from heart rates determined from these two signals was +/-0.6 beats/minute.

  13. Randomised crossover trial of rate feedback and force during chest compressions for paediatric cardiopulmonary resuscitation.

    Science.gov (United States)

    Gregson, Rachael Kathleen; Cole, Tim James; Skellett, Sophie; Bagkeris, Emmanouil; Welsby, Denise; Peters, Mark John

    2017-05-01

    To determine the effect of visual feedback on rate of chest compressions, secondarily relating the forces used. Randomised crossover trial. Tertiary teaching hospital. Fifty trained hospital staff. A thin sensor-mat placed over the manikin's chest measured rate and force. Rescuers applied compressions to the same paediatric manikin for two sessions. During one session they received visual feedback comparing their real-time rate with published guidelines. Primary: compression rate. Secondary: compression and residual forces. Rate of chest compressions (compressions per minute (compressions per minute; cpm)) varied widely (mean (SD) 111 (13), range 89-168), with a fourfold difference in variation during session 1 between those receiving and not receiving feedback (108 (5) vs 120 (20)). The interaction of session by feedback order was highly significant, indicating that this difference in mean rate between sessions was 14 cpm less (95% CI -22 to -5, p=0.002) in those given feedback first compared with those given it second. Compression force (N) varied widely (mean (SD) 306 (94); range 142-769). Those receiving feedback second (as opposed to first) used significantly lower force (adjusted mean difference -80 (95% CI -128 to -32), p=0.002). Mean residual force (18 N, SD 12, range 0-49) was unaffected by the intervention. While visual feedback restricted excessive compression rates to within the prescribed range, applied force remained widely variable. The forces required may differ with growth, but such variation treating one manikin is alarming. Feedback technologies additionally measuring force (effort) could help to standardise and define effective treatments throughout childhood. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  14. Is the normal heart rate ``chaotic'' due to respiration?

    Science.gov (United States)

    Wessel, Niels; Riedl, Maik; Kurths, Jürgen

    2009-06-01

    The incidence of cardiovascular diseases increases with the growth of the human population and an aging society, leading to very high expenses in the public health system. Therefore, it is challenging to develop sophisticated methods in order to improve medical diagnostics. The question whether the normal heart rate is chaotic or not is an attempt to elucidate the underlying mechanisms of cardiovascular dynamics and therefore a highly controversial topical challenge. In this contribution we demonstrate that linear and nonlinear parameters allow us to separate completely the data sets of the three groups provided for this controversial topic in nonlinear dynamics. The question whether these time series are chaotic or not cannot be answered satisfactorily without investigating the underlying mechanisms leading to them. We give an example of the dominant influence of respiration on heart beat dynamics, which shows that observed fluctuations can be mostly explained by respiratory modulations of heart rate and blood pressure (coefficient of determination: 96%). Therefore, we recommend reformulating the following initial question: "Is the normal heart rate chaotic?" We rather ask the following: "Is the normal heart rate `chaotic' due to respiration?"

  15. QRS peak detection for heart rate monitoring on Android smartphone

    Science.gov (United States)

    Pambudi Utomo, Trio; Nuryani, Nuryani; Darmanto

    2017-11-01

    In this study, Android smartphone is used for heart rate monitoring and displaying electrocardiogram (ECG) graph. Heart rate determination is based on QRS peak detection. Two methods are studied to detect the QRS complex peak; they are Peak Threshold and Peak Filter. The acquisition of ECG data is utilized by AD8232 module from Analog Devices, three electrodes, and Microcontroller Arduino UNO R3. To record the ECG data from a patient, three electrodes are attached to particular body’s surface of a patient. Patient’s heart activity which is recorded by AD8232 module is decoded by Arduino UNO R3 into analog data. Then, the analog data is converted into a voltage value (mV) and is processed to get the QRS complex peak. Heart rate value is calculated by Microcontroller Arduino UNO R3 uses the QRS complex peak. Voltage, heart rate, and the QRS complex peak are sent to Android smartphone by Bluetooth HC-05. ECG data is displayed as the graph by Android smartphone. To evaluate the performance of QRS complex peak detection method, three parameters are used; they are positive predictive, accuracy and sensitivity. Positive predictive, accuracy, and sensitivity of Peak Threshold method is 92.39%, 70.30%, 74.62% and for Peak Filter method are 98.38%, 82.47%, 83.61%, respectively.

  16. Effect of Smoking on Blood Pressure and Resting Heart Rate

    DEFF Research Database (Denmark)

    Linneberg, Allan; Jacobsen, Rikke K; Skaaby, Tea

    2015-01-01

    BACKGROUND: -Smoking is an important cardiovascular disease risk factor, but the mechanisms linking smoking to blood pressure are poorly understood. METHODS AND RESULTS: -Data on 141,317 participants (62,666 never, 40,669 former, 37,982 current smokers) from 23 population-based studies were...... included in observational and Mendelian randomisation (MR) meta-analyses of the associations of smoking status and smoking heaviness with systolic and diastolic blood pressure (SBP, DBP), hypertension, and resting heart rate. For the MR analyses, a genetic variant rs16969968/rs1051730 was used as a proxy...... association of smoking heaviness with higher level of resting heart rate, but not with blood pressure. These findings suggest that part of the cardiovascular risk of smoking may operate through increasing resting heart rate....

  17. Effect of oxygen treatment on heart rate after abdominal surgery

    DEFF Research Database (Denmark)

    Rosenberg-Adamsen, S; Lie, C; Bernhard, A

    1999-01-01

    . METHODS: The authors studied the effect of oxygen therapy on arterial oxygen saturation and heart rate in 100 consecutive unselected patients randomly and double blindly allocated to receive air or oxygen therapy between the first and fourth day after major abdominal surgery. RESULTS: The median arterial...... supplementation were found between patients with or without an epidural catheter or between the postoperative day studied. CONCLUSION: Postoperative oxygen therapy increased arterial oxygen saturation and decreased heart rate after uncomplicated abdominal surgery in a consecutive unselected group of patients who......BACKGROUND: Cardiac complications are common during the postoperative period and may be associated with hypoxemia and tachycardia. Preliminary studies in high-risk patients after operation have shown a possible beneficial effect of oxygen therapy on arterial oxygen saturation and heart rate...

  18. Peak heart rate decreases with increasing severity of acute hypoxia

    DEFF Research Database (Denmark)

    Lundby, C; Araoz, M; Van Hall, Gerrit

    2001-01-01

    The purpose of the present study was to investigate the degree to which peak heart rate is reduced during exhaustive exercise in acute hypoxia. Five sea-level lowlanders performed maximal exercise at normobaric normoxia and at three different levels of hypobaric hypoxia (barometric pressures of 518......, 459, and 404 mmHg) in a hypobaric chamber and while breathing 9% O(2) in N(2). These conditions were equivalent to altitudes of 3300, 4300, 5300, and 6300 m above sea level, respectively. At 4300 m, maximal exercise was also repeated after 4 and 8 h. Peak heart rate (HR) decreased from 191 (182...

  19. Heart rate recovery in patients with obstructive sleep apnea syndrome

    OpenAIRE

    Karaşen, Rıza Murat; ÇİFTÇİ, Bülent; Acar, Baran; YALÇIN, Ahmet Arif; GÜVEN, Selma FIRAT

    2014-01-01

    To demonstrate the effects of obstructive sleep apnea syndrome (OSAS) on baroregulatory function by using heart rate recovery (HRR) parameters. Materials and methods: Fifty-four moderate and severe OSAS patients were included in the study. HRR was defined as the difference in heart rate between peak exercise and 1 min later; a value of 18 beats/min was considered abnormal. OSAS patients were enrolled in the study as group 1 (normal HRR; n = 12) and group 2 (abnormal HRR, n = 42). Left ventr...

  20. Electronic fetal heart rate monitoring: applying principles of patient safety.

    Science.gov (United States)

    Miller, David A; Miller, Lisa A

    2012-04-01

    In 1999, a highly publicized report from the Institute of Medicine identified major deficiencies in the United States health care system, which fueled the rapid growth of the modern patient safety movement. One of the greatest risks to patient safety in obstetrics is poor communication of electronic fetal heart rate monitoring findings. Standardization and elimination of unnecessary complexity are 2 of the cornerstones of improved patient safety. This article describes a standardized, simplified approach to the definition, interpretation, and management of electronic fetal heart rate monitoring that is evidence-based and reflects consensus in the literature. Copyright © 2012 Mosby, Inc. All rights reserved.

  1. Heart rate variability as determinism with jump stochastic parameters.

    Science.gov (United States)

    Zheng, Jiongxuan; Skufca, Joseph D; Bollt, Erik M

    2013-08-01

    We use measured heart rate information (RR intervals) to develop a one-dimensional nonlinear map that describes short term deterministic behavior in the data. Our study suggests that there is a stochastic parameter with persistence which causes the heart rate and rhythm system to wander about a bifurcation point. We propose a modified circle map with a jump process noise term as a model which can qualitatively capture such this behavior of low dimensional transient determinism with occasional (stochastically defined) jumps from one deterministic system to another within a one parameter family of deterministic systems.

  2. Heart rate regulation at different levels of convulsive readiness.

    Science.gov (United States)

    Mamalyga, M L

    2013-08-01

    Heart rate variability parameters and the level of convulsive readiness during pentylenetetrazole-induced kindling in rats were analyzed using telemetric ECG and EEG monitoring. Analysis of ECG recorded over many days showed that heart rate variability was equally reduced after 7 and 27 days of kindling irrespective of the level of convulsive readiness. Reduced sympathovagal index after 7 days of kindling showed the compensatory character of changes. However, compensatory mechanisms cannot prevent high risk of life-threatening arrhythmias. High convulsive readiness after 27 days of kindling was accompanied by a shift of autonomic balance towards the increase in sympathetic tone, which may lead to decompensation and transition to a prenosological state.

  3. Dopamine and noradrenaline are unrelated to renalase, heart rate, and blood pressure in heart transplant recipients.

    Science.gov (United States)

    Wasilewski, G; Przybyłowski, P; Janik, L; Nowak, E; Sadowski, J; Małyszko, J

    2014-10-01

    Renalase may degrade catecholamines and regulate sympathetic tone and blood pressure. The aim of this study was to assess dopamine, norepinephrine, and renalase in 80 heart transplant recipients and 22 healthy volunteers and their correlations with heart rate, blood pressure control, type of hypotensive therapy, and renal function. Renalase, dopamine, and norepinephrine were studied by using commercially available assays. Renalase levels were higher in heart transplant recipients compared with healthy volunteers, and noradrenaline levels were lower in the studied cohort patients than in the healthy volunteers. Noradrenaline was correlated with white blood cell count (r = -0.21, P noradrenaline nor dopamine was correlated with heart rate, blood pressure, kidney function, or New York Heart Association class. Noradrenaline was significantly higher in patients with elevated diastolic blood pressure (>90 mm Hg) compared with those with normal diastolic blood pressure (P < .05). Renalase was related to kidney function but was unrelated to catecholamines. Elevated renalase levels in heart transplant patients were related to kidney function but not linked to the sympathetic nervous system activity in this study population. In heart transplant recipients, these findings might suggest that sympathetic denervation and the modulation of β-receptors persist.

  4. When heart goes “BOOM” to fast. Heart rate greater than 80 as mortality predictor in acute myocardial infarction

    OpenAIRE

    Davidovic, Goran; Iric-Cupic, Violeta; Milanov, Srdjan; Dimitijevic, Aleksandra; Petrovic-Janicijevic, Mirjana

    2013-01-01

    Many prospective studies established association between high heart rate and increased cardiovascular morbidity and mortality, independently of other risk factors. Heart rate over 80 beats per minute more often leads to atherosclerotic plaque disruption, the main step in developing acute coronary syndrome. Purpose was to investigate the incidence of higher heart rate levels in patients with anterior wall acute myocardial infarction with ST-segment elevation and the influence of heart rate on ...

  5. Evaluation of the metabolic rate based on the recording of the heart rate.

    Science.gov (United States)

    Malchaire, Jacques; d'AMBROSIO Alfano, Francesca Romana; Palella, Boris Igor

    2017-06-08

    The assessment of harsh working conditions requires a correct evaluation of the metabolic rate. This paper revises the basis described in the ISO 8996 standard for the evaluation of the metabolic rate at a work station from the recording of the heart rate of a worker during a representative period of time. From a review of the literature, formulas different from those given in the standard are proposed to estimate the maximum working capacity, the maximum heart rate, the heart rate and the metabolic rate at rest and the relation (HR vs. M) at the basis of the estimation of the equivalent metabolic rate, as a function of the age, height and weight of the person. A Monte Carlo simulation is used to determine, from the approximations of these parameters and formulas, the imprecision of the estimated equivalent metabolic rate. The results show that the standard deviation of this estimate varies from 10 to 15%.

  6. [Bundle-branch block depending on the heart rate].

    Science.gov (United States)

    Apostolov, L

    1975-01-01

    Five patients are reported, admitted to the hospital, with diseases predominantly of the cardio-vascular system. During the electrocardiographic examinations bundle branch block was established, depending on heart rate. It fluctuated within the physiological limits from 50 to 90/min. In three of the patients, the bundle branch block appeared with the quickening of the heart rate (tachycardia-depending bundle branch block) and in two of the patients--the bundle branch block appeared during the slowing down of the heart action and disappeared with its quickening (bradicardia-depending bundle branch block). A brief literature review is presented and attention is paid to the possible diagnostic errors and the treatment mode of those patients with cardiac tonic and antiarrhythmic medicaments.

  7. Inhalation of ultrafine carbon particles alters heart rate and heart rate variability in people with type 2 diabetes.

    Science.gov (United States)

    Vora, Rathin; Zareba, Wojciech; Utell, Mark J; Pietropaoli, Anthony P; Chalupa, David; Little, Erika L; Oakes, David; Bausch, Jan; Wiltshire, Jelani; Frampton, Mark W

    2014-07-16

    Diabetes may confer an increased risk for the cardiovascular health effects of particulate air pollution, but few human clinical studies of air pollution have included people with diabetes. Ultrafine particles (UFP, ≤100 nm in diameter) have been hypothesized to be an important component of particulate air pollution with regard to cardiovascular health effects. 17 never-smoker subjects 30-60 years of age, with stable type 2 diabetes but otherwise healthy, inhaled either filtered air (0-10 particles/cm3) or elemental carbon UFP (~107 particles/cm3, ~50 ug/m3, count median diameter 32 nm) by mouthpiece, for 2 hours at rest, in a double-blind, randomized, crossover study design. A digital 12-lead electrocardiogram (ECG) was recorded continuously for 48 hours, beginning 1 hour prior to exposure. Analysis of 5-minute segments of the ECG during quiet rest showed reduced high-frequency heart rate variability with UFP relative to air exposure (p = 0.014), paralleled by non-significant reductions in time-domain heart rate variability parameters. In the analysis of longer durations of the ECG, we found that UFP exposure increased the heart rate relative to air exposure. During the 21- to 45-hour interval after exposure, the average heart rate increased approximately 8 beats per minute with UFP, compared to 5 beats per minute with air (p = 0.045). There were no UFP effects on cardiac rhythm or repolarization. Inhalation of elemental carbon ultrafine particles alters heart rate and heart rate variability in people with type 2 diabetes. Our findings suggest that effects may occur and persist hours after a single 2-hour exposure.

  8. Simplifying cardiovascular risk estimation using resting heart rate.

    LENUS (Irish Health Repository)

    Cooney, Marie Therese

    2010-09-01

    Elevated resting heart rate (RHR) is a known, independent cardiovascular (CV) risk factor, but is not included in risk estimation systems, including Systematic COronary Risk Evaluation (SCORE). We aimed to derive risk estimation systems including RHR as an extra variable and assess the value of this addition.

  9. Fetal heart rate variation after corticosteroids for fetal maturation

    NARCIS (Netherlands)

    Knaven, Olga; Ganzevoort, Wessel; de Boer, Marjon; Wolf, Hans

    2017-01-01

    Introduction: Several studies report a decrease of fetal heart rate (FHR) short-term variation (STV) after corticosteroids for improvement of fetal maturity and advice not to deliver a fetus for low STV within 2-3 days after corticosteroids. However, literature is not unanimous in this respect. This

  10. Noradrenaline: Central inhibitory control of blood pressure and heart rate

    NARCIS (Netherlands)

    Jong, Wybren de

    1974-01-01

    Noradrenaline injected bilaterally into the brainstem in the area of the nucleus tractus solitarii decreased systemic arterial blood pressure and heart rate of anesthetized rats. The effect of noradrenaline was prevented by a preceding injection of the α-adrenergic blocking agent phentolamine, at

  11. Allostatic load and heart rate variability as health risk indicators.

    African Journals Online (AJOL)

    Abstract. Background: Uncertainty often exists about the comparability of results obtained by different health risk indicator systems. Objectives: To compare two health risk indicator systems, i.e, allostatic load and heart rate variability (HRV). Additionally, to investigate the feasibility of inclusion of HRV indicators into allostatic ...

  12. Heart Rate Variability and Drawing Impairment in Hypoxemic COPD

    Science.gov (United States)

    Incalzi, Raffaele Antonelli; Corsonello, Andrea; Trojano, Luigi; Pedone, Claudio; Acanfora, Domenico; Spada, Aldo; D'Addio, Gianni; Maestri, Roberto; Rengo, Franco; Rengo, Giuseppe

    2009-01-01

    We studied 54 patients with hypoxemic chronic obstructive pulmonary disease (COPD). The Mini Mental State Examination and the Mental Deterioration Battery were used for neuropsychological assessment. Heart rate variability (HRV) was assessed based on 24-h Holter ECG recording. Mann-Whitney test was used to compare HRV parameters of patients…

  13. [Analysing heart rate variability to improve the monitoring of pain].

    Science.gov (United States)

    Butruille, Laura; De Jonckheere, Julien; Jeanne, Mathieu; Tavernier, Benoît; Logier, Régis

    2016-12-01

    An innovative technique based on the analysis of instantaneous heart rate variability helps to improve the prevention and management of pain and discomfort. Simple to implement, this non-invasive technique is based on the continuous recording of the electrocardiograph signal. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  14. Heart rate variability and sustained attention in ADHD children

    NARCIS (Netherlands)

    Börger, N.A.; Van der Meere, J.J.; Ronner, A.; Alberts, E.; Geuze, R.H.; Bogte, H

    The major goal of the current study was to investigate the association between continuous performance tests (CPTs) and the heart rate variability (HRV) of attention deficit hyperactivity disorder (ADHD) children. The HRV, specifically the 0.10-Hz component, may be considered to be a

  15. Heart Rate Variability Interventions for Concussion and Rehabilitation

    Directory of Open Access Journals (Sweden)

    Robert Lake Conder

    2014-08-01

    Full Text Available The study of Heart Rate Variability (HRV has emerged as an essential component of cardiovascular health, as well as a physiological mechanism by which one can increase the interactive communication between the cardiac and the neurocognitive systems (i.e., the body and the brain. It is well-established that lack of heart rate variability implies cardiopathology, morbidity, reduced quality-of-life, and precipitous mortality. On the positive, optimal heart rate variability has been associated with good cardiovascular health, autonomic nervous system (ANS control, emotional regulation, and enhanced neurocognitive processing. In addition to health benefits, optimal HRV has been shown to improve neurocognitive performance by enhancing focus, visual acuity and readiness, and by promoting emotional regulation needed for peak performance. In concussed athletes and soldiers, concussions not only alter brain connectivity, but also alter cardiac functioning and impair cardiovascular performance upon exertion. Altered sympathetic and parasympathetic balance in the ANS has been postulated as a critical factor in refractory Post Concussive Syndrome (PCS. This article will review both the pathological aspects of reduced heart rate variability on athletic performance, as well as the cardiovascular and cerebrovascular components of concussion and PCS. Additionally, this article will review interventions with HRV biofeedback (HRV BFB training as a promising and underutilized treatment for sports and military-related concussion. Finally, this article will review research and promising case studies pertaining to use of HRV BFB for enhancement of cognition and performance, with applicability to concussion rehabilitation.

  16. Continuous measurement of heart rate variability following carbon ...

    African Journals Online (AJOL)

    2010-07-16

    Jul 16, 2010 ... Power spectral analysis of the electrocardiographic R-R interval [heart rate variability: (HRV)] is a well known, non- invasive method for assessing autonomic nervous activity.1. Studies using HRV analysis during positive-pressure pneumoperitoneum (PPP) have demonstrated increased sympathetic ...

  17. Continuous measurement of heart rate variability following carbon ...

    African Journals Online (AJOL)

    Background: Previous studies of autonomic nervous system activity through analysis of heart rate variability (HRV) have demonstrated increased sympathetic activity during positive-pressure pneumoperitoneum. We employed an online, continuous method for rapid HRV analysis (MemCalc™, Tarawa, Suwa Trust, Tokyo, ...

  18. Applicability and performance of heart rate variability methods

    NARCIS (Netherlands)

    Haaksma, J; Brouwer, J; Dijk, WA; van den Berg, M; Takens, F; Dassen, WRM; Murray, A

    2003-01-01

    Heart Rate Variability (HRV) may be measured using different measurement techniques. Almost all of these techniques deal with ectopic beats. Either these beats are excluded from the analysis or they are required. To access the functional character and easiness of use of several HRV techniques we

  19. Exploring the Relationship between Fetal Heart Rate and Cognition

    Science.gov (United States)

    Kisilevsky, Barbara S.; Hains, Sylvia M. J.

    2010-01-01

    A relationship between fetal heart rate (HR) and cognition is explored within the context of infant, child and adult studies where the association is well established. Lack of direct access to the fetus and maturational changes limit research paradigms and response measures for fetal studies. Nevertheless, neural regulation of HR shows a number of…

  20. Heart Rate and Stress in a College Setting

    Science.gov (United States)

    Elwess, Nancy L.; Vogt, F. Daniel

    2005-01-01

    Conditions producing stress are present in all colleges and universities. In this paper we report on an investigation utilizing heart rate as an indicator of stress in students when participating in activities encountered in a college classroom or laboratory. The activities included presenting an oral report, taking an exam, and participating in a…

  1. Gonadal hormones and heart rate as an emotional response

    NARCIS (Netherlands)

    de Loos, Wolter Statius

    1988-01-01

    Animai experiments may give information on the physiology of hormones under stress conditions. The model for the investigation of acute emotional stress in animals that has been chosen permits the study of heart rate in freely moving laboratory rats as a sensitive psychophysiological parameter, This

  2. Decreased heart rate variability in surgeons during night shifts

    DEFF Research Database (Denmark)

    Amirian, Ilda; Toftegård Andersen, Lærke; Rosenberg, Jacob

    2014-01-01

    BACKGROUND: Heart rate variability (HRV) has been used as a measure of stress and mental strain in surgeons. Low HRV has been associated with death and increased risk of cardiac events in the general population. The aim of this study was to clarify the effect of a 17-hour night shift on surgeons'...

  3. Blood pressure and heart rate adjustment following acute Frenkel's ...

    African Journals Online (AJOL)

    Blood pressure and heart rate adjustment following acute Frenkel's ambulatory exercise in chronic hemiparetics stroke survivors: a comparative study. ... a pre, within and post-activity monitoring of stroke survivors while subjecting them to Frenkel's ambulatory activity. Keys words: cardiovascular, ambulatory activity, stroke ...

  4. Heart Rate Variability: Effect of Exercise Intensity on Postexercise Response

    Science.gov (United States)

    James, David V. B.; Munson, Steven C.; Maldonado-Martin, Sara; De Ste Croix, Mark B. A.

    2012-01-01

    The purpose of the present study was to investigate the influence of two exercise intensities (moderate and severe) on heart rate variability (HRV) response in 16 runners 1 hr prior to (-1 hr) and at +1 hr, +24 hr, +48 hr, and +72 hr following each exercise session. Time domain indexes and a high frequency component showed a significant decrease…

  5. Muscle metaboreflex and autonomic regulation of heart rate in humans

    DEFF Research Database (Denmark)

    Fisher, James P; Adlan, Ahmed M; Shantsila, Alena

    2013-01-01

    We elucidated the autonomic mechanisms whereby heart rate (HR) is regulated by the muscle metaboreflex. Eight male participants (22 ± 3 years) performed three exercise protocols: (1) enhanced metaboreflex activation with partial flow restriction (bi-lateral thigh cuff inflation) during leg cycling...

  6. Early Embryonic Heart Rate in Normal Pregnancies In Memory of ...

    African Journals Online (AJOL)

    To determine the appearance and development of embryonic heart rate a total of n = 317 Nigerian pregnant women were studied in the very early pregnancy from 23 – 56 days from the onset of last menstrual period (LMP). All pregnancies had a subsequent successful outcome. Transvaginal ultrasonography was ...

  7. Allostatic load and heart rate variability as health risk indicators ...

    African Journals Online (AJOL)

    Background: Uncertainty often exists about the comparability of results obtained by different health risk indicator systems. Objectives: To compare two health risk indicator systems, i.e, allostatic load and heart rate variability (HRV). Additionally, to investigate the feasibility of inclusion of HRV indicators into allostatic load ...

  8. The effect of exercise and lifestyle interventions on heart rate ...

    African Journals Online (AJOL)

    The effect of exercise and lifestyle interventions on heart rate variability in students at risk of cardiovascular disease –A pilot study. ... African Journal for Physical Activity and Health Sciences ... Cardiovascular disease is a major public health concern and it can be modified by diet, exercise and health awareness. However ...

  9. QT measurement and heart rate correction during hypoglycemia

    DEFF Research Database (Denmark)

    Christensen, Toke Folke; Randløv, Jette; Christensen, Leif Engmann

    2010-01-01

    Introduction. Several studies show that hypoglycemia causes QT interval prolongation. The aim of this study was to investigate the effect of QT measurement methodology, heart rate correction, and insulin types during hypoglycemia. Methods. Ten adult subjects with type 1 diabetes had hypoglycemia ...

  10. Assessing Metabolic Syndrome Through Increased Heart Rate During Exercise.

    Science.gov (United States)

    Sadeghi, Masoumeh; Gharipour, Mojgan; Nezafati, Pouya; Shafie, Davood; Aghababaei, Esmaeil; Sarrafzadegan, Nizal

    2016-11-01

    The present study aimed to assess changes in resting and maximum heart rates as primary indicators of cardiac autonomic function in metabolic syndrome (MetS) patients and to determine their value for discriminating MetS from non-MetS. 468 participants were enrolled in this cross-sectional study and assessed according to the updated adult treatment panel III (ATP-III) definition of MetS. Resting and maximum heart rates were recorded following the Bruce protocol during an exercise. A receiver operating characteristic (ROC) curve was used to identify the best cutoff point for discriminating MetS from the non-MetS state. 194 participants (41.5%) were diagnosed as MetS. The mean resting heart rate (RHR) was not statistically different between the two groups (P=0.078). However, the mean maximum heart (MHR) rate was considerably higher in participants with MetS (142.37±14.84 beats per min) compared to the non-MetS group (134.62±21.63 beats per min) (Pgroup, the MHR was positively correlated with the serum triglyceride level (β=0.185, P=0.033) and was inversely associated with age (β=-0.469, Page. Moreover, MHR can be used as a suspicious indicator for identifying MetS.

  11. Monitoring of fetal heart rate and uterine activity

    NARCIS (Netherlands)

    Graatsma, E.M.

    2010-01-01

    In this thesis a renewed monitoring technique for fetal heart rate (FHR) and uterine activity has been investigated. Through non-invasive measurements of electrical signals as recorded from the maternal abdomen, both the fetal-electrocardiogram (fECG) and uterine electrohysterogram (EHG) can be

  12. Blood pressure and heart rate adjustment following acute Frenkel's ...

    African Journals Online (AJOL)

    Procedure. This study is a comparative observational study of the pre/post test influence of Frenkel's ambulatory activity on heart rate and blood pressure in hemiparetic stroke survivors undergoing rehabilitation. The study was conducted in the gymnasium of the Department of Physiotherapy, Aminu Kano Teaching Hospital.

  13. Hydration status after exercise affect resting metabolic rate and heart rate variability.

    Science.gov (United States)

    Castro-Sepulveda, Mauricio; Cerda-Kohler, Hugo; Pérez-Luco, Cristian; Monsalves, Matías; Andrade, David Cristobal; Zbinden-Foncea, Herman; Báez-San Martín, Eduardo; Ramírez-Campillo, Rodrigo

    2014-12-17

    Heart rate variability and resting metabolic rate are commonly to assess athlete's physiological status and energy requirements. Exercise-induced dehydration can reach up to 5% of body mass per hour. Consequently, dehydration may have a profound physiological effect on human's homeostasis. To compare the effects of dehydration and rehydration after exercise on heart rate variability and resting metabolic rate in college athletes. 14 college athletes were divided into a dehydration group (n=7) and a rehydration group (n=7), both submitted to basal (T1) heart rate variability and resting metabolic rate measurements. After basal measurements both groups were actively dehydrated (-3.4 ± 0.4% of body mass for both groups). Afterwards, dehydration group rested, while rehydration group receive a fluid intake (during a 3 h period) equivalent to 150% of body mass loss achieved during active dehydration. Four hours after active dehydration heart rate variability and resting metabolic rate were re-assessed (T2). At T2 both rehydration group (+13%) and dehydration group (+30%) achieve a significant (phydration state before resting metabolic rate and heart rate variability assessment. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

  14. Heart rate turbulence analysis in female patients with fibromyalgia.

    Science.gov (United States)

    Dursun, Huseyin; Onrat, Ersel; Ercan, Emine; Demirdal, Umit Secil; Avsar, Alaettin; Dundar, Umit; Solak, Ozlem; Toktas, Hasan

    2015-04-01

    Fibromyalgia is characterized by diffuse musculoskeletal pain and discomfort. There are several reports regarding autonomic nervous system dysfunction in patients with fibromyalgia. Heart rate turbulence is expressed as ventriculophasic sinus arrhythmia and has been considered to reflect cardiac autonomic activity. Heart rate turbulence has been shown to be an independent and powerful predictor of sudden cardiac death in various cardiac abnormalities. The aim of this study is to determine whether heart rate turbulence is changed in female patients with fibromyalgia compared with healthy controls. Thirty-seven female patients (mean age, 40±11 years) with fibromyalgia, and 35 age- and sex-matched healthy female control subjects (mean age, 42±9 years) were included. Twenty-four hours of ambulatory electrocardiography recordings were collected for all subjects, and turbulence onset and turbulence slope values were automatically calculated. The baseline clinical characteristics of the two groups were similar. There were no significant differences in turbulence onset and turbulence slope measures between patients and control subjects (turbulence onset: -1.648±1.568% vs. -1.582±1.436%, p ϝ 0.853; turbulence slope: 12.933±5.693 ms/RR vs. 13.639±2.505 ms/RR, p ϝ 0.508). Although body mass index was negatively correlated with turbulence slope (r ϝ -0.258, p ϝ 0.046), no significant correlation was found between body mass index and turbulence onset (r ϝ 0.228, p ϝ 0.054). To the best of our knowledge, this is the first study to evaluate heart rate turbulence in patients with fibromyalgia. It appears that heart rate turbulence parameters reflecting cardiac autonomic activity are not changed in female patients with fibromyalgia.

  15. The heartbrake of social rejection: heart rate deceleration in response to unexpected peer rejection.

    Science.gov (United States)

    Gunther Moor, Bregtje; Crone, Eveline A; van der Molen, Maurits W

    2010-09-01

    Social relationships are vitally important in human life. Social rejection in particular has been conceptualized as a potent social cue resulting in feelings of hurt. Our study investigated the psychophysiological manifestation of hurt feelings by examining the beat-by-beat heart rate response associated with the processing of social rejection. Study participants were presented with a series of unfamiliar faces and were asked to predict whether they would be liked by the other person. Following each judgment, participants were provided with feedback indicating that the person they had viewed had either accepted or rejected them. Feedback was associated with transient heart rate slowing and a return to baseline that was considerably delayed in response to unexpected social rejection. Our results reveal that the processing of unexpected social rejection is associated with a sizable response of the parasympathetic nervous system. These findings are interpreted in terms of a cardiovagal manifestation of a neural mechanism implicated in the central control of autonomic function during cognitive processes and affective regulation.

  16. A healthy heart is not a metronome: an integrative review of the heart's anatomy and heart rate variability.

    Science.gov (United States)

    Shaffer, Fred; McCraty, Rollin; Zerr, Christopher L

    2014-01-01

    Heart rate variability (HRV), the change in the time intervals between adjacent heartbeats, is an emergent property of interdependent regulatory systems that operate on different time scales to adapt to challenges and achieve optimal performance. This article briefly reviews neural regulation of the heart, and its basic anatomy, the cardiac cycle, and the sinoatrial and atrioventricular pacemakers. The cardiovascular regulation center in the medulla integrates sensory information and input from higher brain centers, and afferent cardiovascular system inputs to adjust heart rate and blood pressure via sympathetic and parasympathetic efferent pathways. This article reviews sympathetic and parasympathetic influences on the heart, and examines the interpretation of HRV and the association between reduced HRV, risk of disease and mortality, and the loss of regulatory capacity. This article also discusses the intrinsic cardiac nervous system and the heart-brain connection, through which afferent information can influence activity in the subcortical and frontocortical areas, and motor cortex. It also considers new perspectives on the putative underlying physiological mechanisms and properties of the ultra-low-frequency (ULF), very-low-frequency (VLF), low-frequency (LF), and high-frequency (HF) bands. Additionally, it reviews the most common time and frequency domain measurements as well as standardized data collection protocols. In its final section, this article integrates Porges' polyvagal theory, Thayer and colleagues' neurovisceral integration model, Lehrer et al.'s resonance frequency model, and the Institute of HeartMath's coherence model. The authors conclude that a coherent heart is not a metronome because its rhythms are characterized by both complexity and stability over longer time scales. Future research should expand understanding of how the heart and its intrinsic nervous system influence the brain.

  17. Ambient air pollution alters heart rate regulation in aged mice.

    Science.gov (United States)

    Ramos-Bonilla, Juan P; Breysse, Patrick N; Dominici, Francesca; Geyh, Alison; Tankersley, Clarke G

    2010-03-01

    Heart rate alterations associated with exposure to particulate matter (PM) and gaseous pollutants have been observed in epidemiological studies and animal experiments. Nevertheless, the time-lag of these associations is still unclear. Determine the association at different time-lags between the complex mixture of ambient concentrations of PM, carbon monoxide (CO), and nitrogen dioxide (NO(2)), and markers of cardiac function in a model of aged mice. AKR/J inbred mice were exposed to ambient air, 6 h daily for 40 weekdays. During this period, the animals' electrocardiogram (ECG), deep body temperature (Tdb), and body weight (BW) were registered, and concentrations of PM, CO, NO(2), as well as air temperature and relative humidity (RH) were measured. Data analysis included random effects models with lagged covariate methods. CO was significantly associated with declines in heart rate (HR) and heart rate variability (HRV), PM was significantly associated with declines in HRV and BW, and NO(2) was significantly associated with declines in HR. Some significant associations occurred in the same day (PM and HRV, PM and BW, CO and HR), whereas others were delayed by 1 to 3 days (CO and HR, CO and HRV, NO(2) and HR, PM and HRV). Finding significant declines in heart function in aged mice associated with the combined effects of air pollutants at ambient concentrations and at different time-lags is of great importance to public health. These results further implicate the potential short term and delayed effects of air pollution on HR alterations.

  18. Asymmetric acceleration/deceleration dynamics in heart rate variability

    Science.gov (United States)

    Alvarez-Ramirez, J.; Echeverria, J. C.; Meraz, M.; Rodriguez, E.

    2017-08-01

    The heart rate variability (HRV) is an important physiological signal used either to assess the risk of cardiac death or to model the cardiovascular regulatory dynamics. Asymmetries in HRV data have been observed using 2D Poincare plots, which have been linked to a non-equilibrium operation of the cardiac autonomic system. This work further explores the presence of asymmetries but in the serial correlations of the dynamics of HRV data. To this end, detrended fluctuation analysis (DFA) was used to estimate the Hurst exponent both when the heart rate is accelerating and when it is decelerating. The analysis is conducted using data collected from subjects under normal sinus rhythm (NSR), congestive heart failure (CHF) and atrial fibrillation (AF) . For the NSR cases, it was found that correlations are stronger (p behavior was detected for the CHF and AF patients. Possible links between asymmetric correlations in the dynamics and the mechanisms controlling the operation of the heart rate are discussed, as well as their implications for modeling the cardiovascular regulatory dynamics.

  19. Heart rate variability in neonates of type 1 diabetic pregnancy.

    Science.gov (United States)

    Russell, Noirin E; Higgins, Mary F; Kinsley, Brendan F; Foley, Michael E; McAuliffe, Fionnuala M

    2016-01-01

    Cardiomyopathy is a common finding in offspring of pre-gestational type 1 diabetic pregnancy. Echocardiographic and biochemical evidence of fetal cardiac dysfunction have also been reported. Studies suggest that offspring of diabetic mothers (ODM) undergo a fetal programming effect due to the hyperglycaemic intrauterine milieu which increases their risk of cardiovascular morbidity in adult life. Decreased neonatal heart rate variability (HRV) has been described in association with in-utero growth restriction, prematurity, sudden infant death syndrome and congenital heart disease. The effect of in-utero exposure to hyperglycaemia in diabetic pregnancy on neonatal HRV is unknown. Our aim was to determine if neonatal HRV differs between normal and diabetic pregnancy. This was a prospective observational study of 38 patients with pregestational type 1 diabetes and 26 controls. HRV assessment was performed using Powerlab (ADI Instruments Ltd). Heart rate variability assessment and cord blood sampling for pH and glucose were performed for all neonates. Maternal glycaemic control was assessed via measurement of glycosylated haemoglobin in each trimester in the diabetic cohort. Neonates of diabetic mothers had evidence of altered heart rate variability, with increased low frequency to high frequency ratio (LF: HF), suggestive of a shift towards sympathetic predominance (pheart to fluctuations in maternal glycaemia with subsequent alterations in HRV may explain why infants of diabetic mothers are at greater risk of cardiovascular disease in later life. Copyright © 2015. Published by Elsevier Ireland Ltd.

  20. When heart goes "BOOM" to fast. Heart rate greater than 80 as mortality predictor in acute myocardial infarction.

    Science.gov (United States)

    Davidovic, Goran; Iric-Cupic, Violeta; Milanov, Srdjan; Dimitijevic, Aleksandra; Petrovic-Janicijevic, Mirjana

    2013-01-01

    Many prospective studies established association between high heart rate and increased cardiovascular morbidity and mortality, independently of other risk factors. Heart rate over 80 beats per minute more often leads to atherosclerotic plaque disruption, the main step in developing acute coronary syndrome. Purpose was to investigate the incidence of higher heart rate levels in patients with anterior wall acute myocardial infarction with ST-segment elevation and the influence of heart rate on mortality. Research included 140 patients with anterior wall acute myocardial infarction with ST-segment elevation treated in Coronary Unit, Clinical Center Kragujevac in the period from January 2001-June 2006. Heart rate was calculated as the mean value of baseline and heart rate in the first 30 minutes after admission. Other risk factors were also followed to determine their connection with elevated heart rate. Results showed that the majority of patients survived (over 70%). In a total number of patients, more than 75% had a heart rate levels greater than 80 beats per minute. There was a significant difference in heart rate on addmision between survivors and patients who died, with a greater levels in patients with fatal outcome. Both, univariate and multivariate regression analysis singled out heart rate greater than 80 beats per minute as independent mortality predictor in these patients. Heart rate greater than 80 beats per minute is a major, independent risk factor for morbidity and important predictor of mortality in patients with acute myocardial infarction.

  1. Rating leniency and halo in multisource feedback ratings: testing cultural assumptions of power distance and individualism-collectivism.

    Science.gov (United States)

    Ng, Kok-Yee; Koh, Christine; Ang, Soon; Kennedy, Jeffrey C; Chan, Kim-Yin

    2011-09-01

    This study extends multisource feedback research by assessing the effects of rater source and raters' cultural value orientations on rating bias (leniency and halo). Using a motivational perspective of performance appraisal, the authors posit that subordinate raters followed by peers will exhibit more rating bias than superiors. More important, given that multisource feedback systems were premised on low power distance and individualistic cultural assumptions, the authors expect raters' power distance and individualism-collectivism orientations to moderate the effects of rater source on rating bias. Hierarchical linear modeling on data collected from 1,447 superiors, peers, and subordinates who provided developmental feedback to 172 military officers show that (a) subordinates exhibit the most rating leniency, followed by peers and superiors; (b) subordinates demonstrate more halo than superiors and peers, whereas superiors and peers do not differ; (c) the effects of power distance on leniency and halo are strongest for subordinates than for peers and superiors; (d) the effects of collectivism on leniency were stronger for subordinates and peers than for superiors; effects on halo were stronger for subordinates than superiors, but these effects did not differ for subordinates and peers. The present findings highlight the role of raters' cultural values in multisource feedback ratings. PsycINFO Database Record (c) 2011 APA, all rights reserved

  2. Diminution of Heart Rate Variability in Bipolar Depression

    Directory of Open Access Journals (Sweden)

    Brandon Hage

    2017-12-01

    Full Text Available Autonomic nervous system (ANS dysregulation in depression is associated with symptoms associated with the ANS. The beat-to-beat pattern of heart rate defined as heart rate variability (HRV provides a noninvasive portal to ANS function and has been proposed to represent a means of quantifying resting vagal tone. We quantified HRV in bipolar depressed (BDD patients as a measure of ANS dysregulation seeking to establish HRV as a potential diagnostic and prognostic biomarker for treatment outcome. Forty-seven BDD patients were enrolled. They were randomized to receive either escitalopram–celecoxib or escitalopram-placebo over 8 weeks in a double-blind study design. Thirty-five patients completed the HRV studies. Thirty-six healthy subjects served as controls. HRV was assessed at pretreatment and end of study and compared with that of controls. HRV was quantified and corrected for artifacts using an algorithm that incorporates time and frequency domains to address non-stationarity of the beat-to-beat heart rate pattern. Baseline high frequency-HRV (i.e., respiratory sinus arrhythmia was lower in BDD patients than controls, although the difference did not reach significance. Baseline low-frequency HRV was significantly lower in BDD patients (ln4.20 than controls (ln = 5.50 (p < 0.01. Baseline heart period was significantly shorter (i.e., faster heart rate in BDD patients than controls. No significant change in HRV parameters were detected over the course of the study with either treatment. These findings suggest that components of HRV may be diminished in BDD patients.

  3. Endogenous vasopressin and the central control of heart rate during dynamic exercise

    Directory of Open Access Journals (Sweden)

    L.C. Michelini

    1998-09-01

    Full Text Available The present article contains a brief review on the role of vasopressinergic projections to the nucleus tractus solitarii in the genesis of reflex bradycardia and in the modulation of heart rate control during exercise. The effects of vasopressin on exercise tachycardia are discussed on the basis of both the endogenous peptide content changes and the heart rate response changes observed during running in sedentary and trained rats. Dynamic exercise caused a specific vasopressin content increase in dorsal and ventral brainstem areas. In accordance, rats pretreated with the peptide or the V1 blocker into the nucleus tractus solitarii showed a significant potentiation or a marked blunting of the exercise tachycardia, respectively, without any change in the pressure response to exercise. It is proposed that the long-descending vasopressinergic pathway to the nucleus tractus solitarii serves as one link between the two main neural controllers of circulation, i.e., the central command and feedback control mechanisms driven by the peripheral receptors. Therefore, vasopressinergic input could contribute to the adjustment of heart rate response (and cardiac output to the circulatory demand during exercise.

  4. Computed tomography coronary angiography with heart rate control premedication: a best practice implementation project.

    Science.gov (United States)

    Mander, Gordon Thomas Waterland

    2017-07-01

    Computed tomography coronary angiography patient preparation with heart rate control premedication is employed in departments across Australia. However, the methods of administration vary widely between institutions and do not always follow best practice. This aim of the study was to identify and promote best practice in the administration of heart rate premedication in computed tomography coronary angiography at a regional hospital in Australia. The Joanna Briggs Institute have validated audit and feedback tools to assist with best practice implementation projects. This project used these tools, which involve three phases of activity - a pre-implementation audit, reflecting on results and implementing strategies to address non-compliance, and a post-implementation audit to assess the outcomes. A baseline audit identified non-compliance in the majority of measured audit criteria. Following implementation of an institution-specific guideline and associated worksheet, improved compliance was shown across all audit criteria. Following the development and implementation of institution-specific evidence-based resources relating to heart rate control in computed tomography coronary angiography, a high level of compliance consistent with best practice was achieved.

  5. Has electronic fetal heart rate monitoring made a difference.

    Science.gov (United States)

    Steer, Philip J

    2008-02-01

    Electronic fetal heart rate monitoring (EFHRM) has revolutionised our understanding of the function of the cardiovascular system of the fetus during labour, and how the fetus responds to hypoxia. However, although it is a sensitive technique for the detection of hypoxia during labour, it is relatively non-specific for detecting the development of acidosis. Moreover, it is highly dependent on accurate interpretation of fetal heart rate (FHR) patterns, which has been shown to be commonly of a low standard in everyday clinical practice. Use of EFHRM has probably reduced the incidence of birth asphyxia, but it has also contributed to the rise in the caesarean section rate. Ancillary techniques, such as pulse oximetry, have not proved useful, although ST-segment analysis of the ECG waveform shows some promise. Computerised expert systems for the analysis of FHR patterns may be more successful at avoiding poor outcomes.

  6. [Research on conditional fluctuation characteristics of CHF heart rate variation].

    Science.gov (United States)

    Si, Junfeng; Zhou, Lingling; Huang, Xiaoling; Bian, Chunhua

    2013-12-01

    In this study, we applied generalized autoregressive conditional heteroskedasticity (GARCH) model to conditional fluctuation characteristics of heart rate variation (HRV) series (congestive heart failure, Normal), with all the data from PhysioNet ECG database. Research results proved the existence of condition fluctuation characteristic in the series of changing rate of HRV. In the GARCH model family, threshold GARCH (1,1)(TGARCH (1,1)) model performs best in fitting changing rate of HRV. Although the structure of ARCH (1) model is simple, its error is the closest to that of TGARCH (1, 1) model. The results also showed that the difference was obvious between disease group and normal group. All these results provide a new method to the research and clinical application of HRV.

  7. Heart Rate and Heart Rate Variability in Dairy Cows with Different Temperament and Behavioural Reactivity to Humans.

    Directory of Open Access Journals (Sweden)

    Levente Kovács

    Full Text Available From the 1990s, extensive research was started on the physiological aspects of individual traits in animals. Previous research has established two extreme (proactive and reactive coping styles in several animal species, but the means of reactivity with the autonomic nervous system (ANS activity has not yet been investigated in cattle. The aim of this study was the characterization of cardiac autonomic activity under different conditions in cows with different individual characteristics. For this purpose, we investigated heart rate and ANS-related heart rate variability (HRV parameters of dairy cows (N = 282 on smaller- and larger-scale farms grouped by (1 temperament and (2 behavioural reactivity to humans (BRH. Animals with high BRH scores were defined as impulsive, while animals with low BRH scores were defined as reserved. Cardiac parameters were calculated for undisturbed lying (baseline and for milking bouts, the latter with the presence of an unfamiliar person (stressful situation. Sympathetic tone was higher, while vagal activity was lower in temperamental cows than in calm animals during rest both on smaller- and larger-scale farms. During milking, HRV parameters were indicative of a higher sympathetic and a lower vagal activity of temperamental cows as compared to calm ones in farms of both sizes. Basal heart rate did not differ between BRH groups either on smaller- or larger-scale farms. Differences between basal ANS activity of impulsive and reserved cows reflected a higher resting vagal and lower sympathetic activity of reserved animals compared to impulsive ones both on smaller- and larger-scale farms. There was no difference either in heart rate or in HRV parameters between groups during milking neither in smaller- nor in larger-scale farms. These two groupings allowed to draw possible parallels between personality and cardiac autonomic activity during both rest and milking in dairy cows. Heart rate and HRV seem to be useful for

  8. A new physiological method for heart rate correction of the QT interval

    OpenAIRE

    Davey, P.

    1999-01-01

    AIM—To reassess QT interval rate correction.
BACKGROUND—The QT interval is strongly and inversely related to heart rate. To compare QT intervals between different subjects with different heart rates requires the application of a QT interval rate correction formula. To date these formulae have inappropriately assumed a fixed relation between QT interval and heart rate. An alternative method of QT interval rate correction that makes no assumptions about the QT interval-heart rate relation is ne...

  9. General anesthesia suppresses normal heart rate variability in humans

    Science.gov (United States)

    Matchett, Gerald; Wood, Philip

    2014-06-01

    The human heart normally exhibits robust beat-to-beat heart rate variability (HRV). The loss of this variability is associated with pathology, including disease states such as congestive heart failure (CHF). The effect of general anesthesia on intrinsic HRV is unknown. In this prospective, observational study we enrolled 100 human subjects having elective major surgical procedures under general anesthesia. We recorded continuous heart rate data via continuous electrocardiogram before, during, and after anesthesia, and we assessed HRV of the R-R intervals. We assessed HRV using several common metrics including Detrended Fluctuation Analysis (DFA), Multifractal Analysis, and Multiscale Entropy Analysis. Each of these analyses was done in each of the four clinical phases for each study subject over the course of 24 h: Before anesthesia, during anesthesia, early recovery, and late recovery. On average, we observed a loss of variability on the aforementioned metrics that appeared to correspond to the state of general anesthesia. Following the conclusion of anesthesia, most study subjects appeared to regain their normal HRV, although this did not occur immediately. The resumption of normal HRV was especially delayed on DFA. Qualitatively, the reduction in HRV under anesthesia appears similar to the reduction in HRV observed in CHF. These observations will need to be validated in future studies, and the broader clinical implications of these observations, if any, are unknown.

  10. Haptic feedback enhances rhythmic motor control by reducing variability, not improving convergence rate.

    Science.gov (United States)

    Ankarali, M Mert; Tutkun Sen, H; De, Avik; Okamura, Allison M; Cowan, Noah J

    2014-03-01

    Stability and performance during rhythmic motor behaviors such as locomotion are critical for survival across taxa: falling down would bode well for neither cheetah nor gazelle. Little is known about how haptic feedback, particularly during discrete events such as the heel-strike event during walking, enhances rhythmic behavior. To determine the effect of haptic cues on rhythmic motor performance, we investigated a virtual paddle juggling behavior, analogous to bouncing a table tennis ball on a paddle. Here, we show that a force impulse to the hand at the moment of ball-paddle collision categorically improves performance over visual feedback alone, not by regulating the rate of convergence to steady state (e.g., via higher gain feedback or modifying the steady-state hand motion), but rather by reducing cycle-to-cycle variability. This suggests that the timing and state cues afforded by haptic feedback decrease the nervous system's uncertainty of the state of the ball to enable more accurate control but that the feedback gain itself is unaltered. This decrease in variability leads to a substantial increase in the mean first passage time, a measure of the long-term metastability of a stochastic dynamical system. Rhythmic tasks such as locomotion and juggling involve intermittent contact with the environment (i.e., hybrid transitions), and the timing of such transitions is generally easy to sense via haptic feedback. This timing information may improve metastability, equating to less frequent falls or other failures depending on the task.

  11. What Does an Executive Coaching Intervention Add beyond Facilitated Multisource Feedback? Effects on Leader Self-Ratings and Perceived Effectiveness

    Science.gov (United States)

    Nieminen, Levi R. G.; Smerek, Ryan; Kotrba, Lindsey; Denison, Daniel

    2013-01-01

    Multisource ratings and feedback are now central components of many leader development programs. Research evaluating the outcomes of multisource feedback (MSF) underscores the importance of facilitation strategies that help leaders to interpret and use their feedback throughout the development process. Scholars and practitioners have recommended…

  12. Linear and Nonlinear Heart Rate Variability Indexes in Clinical Practice

    Directory of Open Access Journals (Sweden)

    Buccelletti Francesco

    2012-01-01

    Full Text Available Biological organisms have intrinsic control systems that act in response to internal and external stimuli maintaining homeostasis. Human heart rate is not regular and varies in time and such variability, also known as heart rate variability (HRV, is not random. HRV depends upon organism's physiologic and/or pathologic state. Physicians are always interested in predicting patient's risk of developing major and life-threatening complications. Understanding biological signals behavior helps to characterize patient's state and might represent a step toward a better care. The main advantage of signals such as HRV indexes is that it can be calculated in real time in noninvasive manner, while all current biomarkers used in clinical practice are discrete and imply blood sample analysis. In this paper HRV linear and nonlinear indexes are reviewed and data from real patients are provided to show how these indexes might be used in clinical practice.

  13. Association between oral variables and heart rate variability.

    Science.gov (United States)

    Santana, Milana Drumond Ramos; de Souza, Ana Cecilia Amorim; de Abreu, Luiz Carlos; Valenti, Vitor E

    2013-12-27

    The heart rate variability is a useful method to assess cardiac autonomic modulation in patients undergoing dental procedures, because knowledge of physiological conditions provides greater security to the professional as well as the possibility of a better plan treatment to patient benefit. The aim of our study was to describe the association between cardiac autonomic control and dental variables. We consulted the databases Medline, SciELO, Lilacs and Cochrane, using the terms "autonomic", "dentistry", "heart rate variability", "cardiovascular physiology." The selected studies indicated a strong relationship between dental variables and HRV. There was an association between malocclusion, TMD, dental procedures cirugia and low HRV. Thus, they become more studies that relate to HRV in dental science, especially in clinical practice.

  14. [Heart rate variability during sleep in children with multiple disabilities].

    Science.gov (United States)

    Bouquier, L; Amand, M; Van Eecke, D

    2013-12-01

    To study heart rate variability during sleep in children with multiple disabilities in order to observe the behavior of the autonomic nervous system. The R-R interval variability of 4 to 12 years old children was recorded with a heart rate monitor during one night. Children with multiple disabilities (G1) and healthy children (G2) were compared in time, frequency, and non-linear domains. Temporal (P0.05). The diseases encountered are probably the reason for these findings, but the variety of disorders and medications of the children with multiple disabilities needs to be studied with a larger and more varied sample. Sympathetic predominance during sleep in children with multiple disabilities is associated with a decrease in adaptive abilities of these children's autonomic nervous system. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  15. Cholesterol enhances classical conditioning of the rabbit heart rate response.

    Science.gov (United States)

    Schreurs, Bernard G; Smith-Bell, Carrie A; Darwish, Deya S; Wang, Desheng; Burhans, Lauren B; Gonzales-Joekes, Jimena; Deci, Stephen; Stankovic, Goran; Sparks, D Larry

    2007-07-19

    The cholesterol-fed rabbit is a model of atherosclerosis and has been proposed as an animal model of Alzheimer's disease. Feeding rabbits cholesterol has been shown to increase the number of beta amyloid immunoreactive neurons in the cortex. Addition of copper to the drinking water of cholesterol-fed rabbits can increase this number still further and may lead to plaque-like structures. Classical conditioning of the nictitating membrane response in cholesterol-fed rabbits is retarded in the presence of these plaque-like structures but may be facilitated in their absence. In a factorial design, rabbits fed 2% cholesterol or a normal diet (0% cholesterol) for 8 weeks with or without copper added to the drinking water were given trace classical conditioning using a tone and periorbital electrodermal stimulation to study the effects of cholesterol and copper on classical conditioning of heart rate and the nictitating membrane response. Cholesterol-fed rabbits showed significant facilitation of heart rate conditioning and conditioning-specific modification of heart rate relative to normal diet controls. Consistent with previous research, cholesterol had minimal effects on classical conditioning of the nictitating membrane response when periorbital electrodermal stimulation was used as the unconditioned stimulus. Immunohistochemical analysis showed a significant increase in the number of beta amyloid positive neurons in the cortex, hippocampus and amygdala of the cholesterol-fed rabbits. Supplementation of drinking water with copper increased the number of beta amyloid positive neurons in the cortex of cholesterol-fed rabbits but did not produce plaque-like structures or have a significant effect on heart rate conditioning. The data provide additional support for our finding that, in the absence of plaques, dietary cholesterol may facilitate learning and memory.

  16. Assessing Metabolic Syndrome Through Increased Heart Rate During Exercise

    Directory of Open Access Journals (Sweden)

    Masoumeh Sadeghi

    2016-12-01

    Full Text Available The present study aimed to assess changes in resting and maximum heart rates as primary indicators of cardiac autonomic function in metabolic syndrome (MetS patients and to determine their value for discriminating MetS from non-MetS. 468 participants were enrolled in this cross-sectional study and assessed according to the updated adult treatment panel III (ATP-III definition of MetS. Resting and maximum heart rates were recorded following the Bruce protocol during an exercise. A receiver operating characteristic (ROC curve was used to identify the best cutoff point for discriminating MetS from the non-MetS state. 194 participants (41.5% were diagnosed as MetS. The mean resting heart rate (RHR was not statistically different between the two groups (P=0.078. However, the mean maximum heart (MHR rate was considerably higher in participants with MetS (142.37±14.84 beats per min compared to the non-MetS group (134.62±21.63 beats per min (P<0.001. In the MetS group, the MHR was positively correlated with the serum triglyceride level (β=0.185, P=0.033 and was inversely associated with age (β=-0.469, P<0.001. The MHR had a moderate value for discriminating MetS from the non-MetS state (c=0.580, P=0.004 with the optimal cutoff point of 140 beats per min. In MetS patients, the MHR was significantly greater compared to non-MetS subjects and was directly correlated with serum triglyceride levels and inversely with advanced age. Moreover, MHR can be used as a suspicious indicator for identifying MetS.

  17. Applying Hyperspectral Imaging to Heart Rate Estimation for Adaptive Automation

    Science.gov (United States)

    2013-03-01

    Walker, G. H., Baber , C., & Jenkins, D. P. (2005). Human Factors Methods: A Practical Guide for Engineering and Design. Burlington, VT: Ashgate...the training, subjects were asked if they were ready to begin the experiment or if they wanted any extra time to practice . Test Sessions and Testing...intrusive and not practical for day-to-day operations. Several imaging techniques have been developed to remotely measure heart rate; however, each

  18. Active random noise control using adaptive learning rate neural networks with an immune feedback law

    Science.gov (United States)

    Sasaki, Minoru; Kuribayashi, Takumi; Ito, Satoshi

    2005-12-01

    In this paper an active random noise control using adaptive learning rate neural networks with an immune feedback law is presented. The adaptive learning rate strategy increases the learning rate by a small constant if the current partial derivative of the objective function with respect to the weight and the exponential average of the previous derivatives have the same sign, otherwise the learning rate is decreased by a proportion of its value. The use of an adaptive learning rate attempts to keep the learning step size as large as possible without leading to oscillation. In the proposed method, because of the immune feedback law change a learning rate of the neural networks individually and adaptively, it is expected that a cost function minimize rapidly and training time is decreased. Numerical simulations and experiments of active random noise control with the transfer function of the error path will be performed, to validate the convergence properties of the adaptive learning rate Neural Networks with the immune feedback law. Control results show that adaptive learning rate Neural Networks control structure can outperform linear controllers and conventional neural network controller for the active random noise control.

  19. Classifying work rate from heart rate measurements using an adaptive neuro-fuzzy inference system.

    Science.gov (United States)

    Kolus, Ahmet; Imbeau, Daniel; Dubé, Philippe-Antoine; Dubeau, Denise

    2016-05-01

    In a new approach based on adaptive neuro-fuzzy inference systems (ANFIS), field heart rate (HR) measurements were used to classify work rate into four categories: very light, light, moderate, and heavy. Inter-participant variability (physiological and physical differences) was considered. Twenty-eight participants performed Meyer and Flenghi's step-test and a maximal treadmill test, during which heart rate and oxygen consumption (VO2) were measured. Results indicated that heart rate monitoring (HR, HRmax, and HRrest) and body weight are significant variables for classifying work rate. The ANFIS classifier showed superior sensitivity, specificity, and accuracy compared to current practice using established work rate categories based on percent heart rate reserve (%HRR). The ANFIS classifier showed an overall 29.6% difference in classification accuracy and a good balance between sensitivity (90.7%) and specificity (95.2%) on average. With its ease of implementation and variable measurement, the ANFIS classifier shows potential for widespread use by practitioners for work rate assessment. Copyright © 2015 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  20. Heating and cooling rates and their etTects upon heart rate in the ...

    African Journals Online (AJOL)

    1988-03-16

    Mar 16, 1988 ... have investigated aspects of thermoregulation, but the results obtained are contradictory, and no heart rate measurements were done. The purpose of this study was to investigate the heating and cooling rates of the angulate tortoise, Chersina angulata, in the eastern Cape Province,. South Africa.

  1. Heating and cooling rates and their effects upon heart rate in the ...

    African Journals Online (AJOL)

    ... rates increase with increasing body temperature, and for all body temperatures heart rates were greater during heating than during cooling. This suggests that the cardiovascular system plays a role in the heat exchange of the tortoises, but further study is required to completely understand the thermoregulatory process.

  2. Emotions, heart rate and performance in archery. A case study.

    Science.gov (United States)

    Robazza, C; Bortoli, L; Nougier, V

    1999-06-01

    A case study of an elite female archer was conducted to gain insight into individual psychophysical reactions accompanying an athletic event, and to test predictions of pre-performance emotions effects upon performance. Good performance was expected when the actual pre-performance emotions resembled the recalled optimal emotion pattern. Conversely, poor performance was expected when the actual pre-performance emotions paralleled the recalled ineffective emotion pattern. the investigation comprised individual emotion profiling, emotions and heart rate monitoring, final interview and performance evaluation. The research was accomplished during the 1996 European Archery Championships, one of the most important international archery competitions. An 18-year-old female athlete of the Italian archery national team. Because of the exploratory nature of the study, no intervention was implemented. Emotion profiling was carried out using an idiographic approach based on recalled optimal and poor performances, according to the Individual Zones of Optimal Functioning (IZOF) model. Emotions, heart rate, and performance were monitored across the five days of practice and competition. Individual pre-performance optimal emotion pattern, heart rate deceleration during shooting, consistent shooting scores were revealed throughout practice and competition. The good performance predicted on the basis of pre-performance emotion assessments was met and was confirmed by the archer's interpretation.

  3. Assessing heart rate variability through wavelet-based statistical measures.

    Science.gov (United States)

    Wachowiak, Mark P; Hay, Dean C; Johnson, Michel J

    2016-10-01

    Because of its utility in the investigation and diagnosis of clinical abnormalities, heart rate variability (HRV) has been quantified with both time and frequency analysis tools. Recently, time-frequency methods, especially wavelet transforms, have been applied to HRV. In the current study, a complementary computational approach is proposed wherein continuous wavelet transforms are applied directly to ECG signals to quantify time-varying frequency changes in the lower bands. Such variations are compared for resting and lower body negative pressure (LBNP) conditions using statistical and information-theoretic measures, and compared with standard HRV metrics. The latter confirm the expected lower variability in the LBNP condition due to sympathetic nerve activity (e.g. RMSSD: p=0.023; SDSD: p=0.023; LF/HF: p=0.018). Conversely, using the standard Morlet wavelet and a new transform based on windowed complex sinusoids, wavelet analysis of the ECG within the observed range of heart rate (0.5-1.25Hz) exhibits significantly higher variability, as measured by frequency band roughness (Morlet CWT: p=0.041), entropy (Morlet CWT: p=0.001), and approximate entropy (Morlet CWT: p=0.004). Consequently, this paper proposes that, when used with well-established HRV approaches, time-frequency analysis of ECG can provide additional insights into the complex phenomenon of heart rate variability. Copyright © 2016. Published by Elsevier Ltd.

  4. Stress Detection Using Low Cost Heart Rate Sensors

    Directory of Open Access Journals (Sweden)

    Mario Salai

    2016-01-01

    Full Text Available The automated detection of stress is a central problem for ambient assisted living solutions. The paper presents the concepts and results of two studies targeted at stress detection with a low cost heart rate sensor, a chest belt. In the device validation study (n=5, we compared heart rate data and other features from the belt to those measured by a gold standard device to assess the reliability of the sensor. With simple synchronization and data cleaning algorithm, we were able to select highly (>97% correlated, low average error (2.2% data segments of considerable length from the chest data for further processing. The protocol for the clinical study (n=46 included a relax phase followed by a phase with provoked mental stress, 10 minutes each. We developed a simple method for the detection of the stress using only three time-domain features of the heart rate signal. The method produced accuracy of 74.6%, sensitivity of 75.0%, and specificity of 74.2%, which is impressive compared to the performance of two state-of-the-art methods run on the same data. Since the proposed method uses only time-domain features, it can be efficiently implemented on mobile devices.

  5. Practical remarks on the heart rate and saturation measurement methodology

    Science.gov (United States)

    Kowal, M.; Kubal, S.; Piotrowski, P.; Staniec, K.

    2017-05-01

    A surface reflection-based method for measuring heart rate and saturation has been introduced as one having a significant advantage over legacy methods in that it lends itself for use in special applications such as those where a person’s mobility is of prime importance (e.g. during a miner’s work) and excluding the use of traditional clips. Then, a complete ATmega1281-based microcontroller platform has been described for performing computational tasks of signal processing and wireless transmission. In the next section remarks have been provided regarding the basic signal processing rules beginning with raw voltage samples of converted optical signals, their acquisition, storage and smoothing. This chapter ends with practical remarks demonstrating an exponential dependence between the minimum measurable heart rate and the readout resolution at different sampling frequencies for different cases of averaging depth (in bits). The following section is devoted strictly to the heart rate and hemoglobin oxygenation (saturation) measurement with the use of the presented platform, referenced to measurements obtained with a stationary certified pulsoxymeter.

  6. Ivabradine reduces heart rate while preserving metabolic fluxes and energy status of healthy normoxic working hearts.

    Science.gov (United States)

    Lauzier, Benjamin; Vaillant, Fanny; Gélinas, Roselle; Bouchard, Bertrand; Brownsey, Roger; Thorin, Eric; Tardif, Jean-Claude; Des Rosiers, Christine

    2011-03-01

    Heart rate reduction (HRR) is an important target in the management of patients with chronic stable angina. Most available drugs for HRR, such as β-blockers, have adverse effects, including on cardiac energy substrate metabolism, a well-recognized determinant of cardiac homeostasis. This study aimed at 1) testing whether HRR by ivabradine (IVA) alters substrate metabolism in the healthy normoxic working heart and 2) comparing the effect of IVA with that of the β-blocker metoprolol (METO). This was assessed using our well-established model of ex vivo mouse heart perfusion in the working mode, which enables concomitant evaluation of myocardial contractility and metabolic fluxes using (13)C-labeled substrates. Hearts were perfused in the absence (controls; n = 10) or presence of IVA (n = 10, 3 μM) with or without atrial pacing to abolish HRR in the IVA group. IVA significantly reduced HR (35 ± 5%) and increased stroke volume (39 ± 9%) while maintaining similar cardiac output, contractility, power, and efficiency. Effects of IVA on HR and stroke volume were reversed by atrial pacing. At the metabolic level, IVA did not impact on substrate selection to citrate formation, rates of glycolysis, or tissue levels of high-energy phosphates. In contrast, METO, at concentrations up to 40 μM, decreased markedly cardiac function (flow: 25 ± 6%; stroke volume: 30 ± 10%; contractility: 31 ± 9%) as well as glycolysis (2.9-fold) but marginally affected HR. Collectively, these results demonstrate that IVA selectively reduces HR while preserving energy substrate metabolism of normoxic healthy working mouse hearts perfused ex vivo, a model that mimics to some extent the denervated transplanted heart. Our results provide the impetus for testing selective HRR by IVA on cardiac substrate metabolism in pathological models.

  7. Is there a relationship between obesity, heart rate variability and inflammatory parameters in heart failure?

    Science.gov (United States)

    Taçoy, Gülten; Açikgöz, Kadri; Kocaman, Sinan Altan; Ozdemir, Murat; Cengel, Atiye

    2010-02-01

    To investigate the effect of body mass index (BMI) on heart rate variability (HRV) and inflammatory parameters in patients with heart failure. We analyzed 55 consecutive patients (mean age, 63.5 +/- 12.8 years; male/female, 39/16) with symptomatic left ventricular systolic (ejection fraction or= 30 kg/m2). The cause of heart failure was mainly ischemic heart disease (75%) with mean ejection fraction 30 +/- 7%. Plasma N-terminal pro-brain natriuretic peptide (NT-proBNP) and C-reactive protein levels were measured, and time-domain HRV indices were determined on Holter electrocardiogram. The relationship between HRV indices and laboratory, inflammatory and echocardiographic parameters was investigated with correlation analysis. Age, sex, clinical characteristics (hypertension, diabetes mellitus, dyslipidemia, family history, smoking) were similar between groups. BMI was inversely correlated with NT-pro BNP levels (P = 0.001). HRV indices did not differ between groups. Correlation analysis demonstrated the relationship between HRV indices and fasting blood glucose (SDNN, SDANN, SDNNI, root mean square successive differences, VTI), C-reactive protein (SDANN, SDNNI, VTI), pulmonary artery pressure (SDNN, SDANN, VTI) levels. In systolic heart failure patients a higher BMI is associated with decreased NT-proBNP levels. Although HRV indices were not different between groups, inflammatory parameters, fasting blood glucose and pulmonary artery pressure were correlated with them.

  8. Relationship between exercise heart rate and music tempo preference

    OpenAIRE

    Karageorghis, CI; Jones, L; Low, DC

    2006-01-01

    The present study examined the predicted positive and linear relationship (Iwanaga, 1995a,1995b) between exercise heart rate and music tempo preference. Initially, 128 undergraduates (M 3 age = 20.0 years, SD = 0.9 years) were surveyed to establish their three favorite music artists of all time. A separate experimental group of 29 undergraduates (M age = 20.3 years, SD = 1.2 years) selected the music of a single artist from a choice of the three highest-rated artists from the earlier survey. ...

  9. Catecholamine-Independent Heart Rate Increases Require CaMKII

    Science.gov (United States)

    Gao, Zhan; Singh, Madhu V; Hall, Duane D; Koval, Olha M.; Luczak, Elizabeth D.; Joiner, Mei-ling A.; Chen, Biyi; Wu, Yuejin; Chaudhary, Ashok K; Martins, James B; Hund, Thomas J; Mohler, Peter J; Song, Long-Sheng; Anderson, Mark E.

    2011-01-01

    Background Catecholamines increase heart rate by augmenting the cAMP responsive HCN4 ‘pacemaker current’ (If) and/or by promoting inward Na+/Ca2+ exchanger current (INCX), by a ‘Ca2+ clock’ mechanism in sinoatrial nodal cells (SANCs). The importance, identity and function of signals that connect If and Ca2+ clock mechanisms are uncertain and controversial, but the multifunctional Ca2+ and calmodulin-dependent protein kinase II (CaMKII) is required for physiological heart rate responses to β-adrenergic receptor (β-AR) stimulation. The aim of this stuy is to measure the contribution of the Ca2+ clock and CaMKII to cardiac pacing independent of β-AR agonist stimulation. Methods and Results We used the L-type Ca2+ channel agonist BayK 8644 (BayK) to activate the SANC Ca2+ clock. BayK and isoproterenol were similarly effective in increasing rates in SANCs and Langendorff-perfused hearts from WT control mice. In contrast, SANCs and isolated hearts from mice with CaMKII inhibition by transgenic expression of an inhibitory peptide (AC3-I) were resistant to rate increases by BayK. BayK only activated CaMKII in control SANCs, but increased ICa equally in all SANCs, indicating that increasing ICa was insufficient and suggesting CaMKII activation was required for heart rate increases by BayK. BayK did not increase If or protein kinase A (PKA)-dependent phosphorylation of phospholamban (at Ser16), indicating that increased SANC Ca2+ by BayK did not augment cAMP/PKA signaling at these targets. Late diastolic intracellular Ca2+ release and INCX were significantly reduced in AC3-I SANCs and the response to BayK was eliminated by ryanodine in all groups. Conclusions The Ca2+ clock is capable of supporting physiological fight or flight responses, independent of β-AR stimulation or If increases. Complete Ca2+ clock and β-AR stimulation responses require CaMKII. PMID:21406683

  10. Bluetooth(Registered Trademark) Heart Rate Monitors for Spaceflight

    Science.gov (United States)

    Buxton, Roxanne E.; West, Michael R.; Kalogera, Kent L.; Hanson, Andrea M.

    2016-01-01

    Heart rate monitoring is required during exercise for crewmembers aboard the International Space Station (ISS) and will be for future exploration missions. The cardiovascular system must be sufficiently stressed throughout a mission to maintain the ability to perform nominal and contingency/emergency tasks. High quality heart rate data is required to accurately determine the intensity of exercise performed by the crewmembers and show maintenance of VO2max. The quality of the data collected on ISS is subject to multiple limitations and is insufficient to meet current requirements. PURPOSE: To evaluate the performance of commercially available Bluetooth® heart rate monitors (BT_HRM) and their ability to provide high quality heart rate data to monitor crew health on board ISS and during future exploration missions. METHODS: Nineteen subjects completed 30 data collection sessions of various intensities on the treadmill and/or cycle. Subjects wore several BT_HRM technologies for each testing session. One electrode-based chest strap (CS) was worn, while one or more optical sensors (OS) was worn. Subjects were instrumented with a 12-lead ECG to compare the heart rate data from the Bluetooth sensors. Each BT_RHM data set was time matched to the ECG data and a +/-5bpm threshold was applied to the difference between the two data sets. Percent error was calculated based on the number of data points outside the threshold and the total number of data points. REULTS: The electrode-based chest straps performed better than the optical sensors. The best performing CS was CS1 (1.6%error), followed by CS4 (3.3%error), CS3 (6.4%error), and CS2 (9.2%error). The OS resulted in 10.4% error for OS1 and 14.9% error for OS2. CONCLUSIONS: The highest quality data came from CS1, unfortunately it has been discontinued by the manufacturer. The optical sensors have not been ruled out for use, but more investigation is needed to determine how to get the best quality data. CS2 will be used in an

  11. Muscular Contraction Mode Differently Affects Autonomic Control During Heart Rate Matched Exercise

    Directory of Open Access Journals (Sweden)

    Matthias eWeippert

    2015-05-01

    Full Text Available The precise contributions of afferent feedback to cardiovascular and respiratory responses to exercise are still unclear. Aim of this crossover study was to assess whether and how autonomic cardiovascular and respiratory control differed in response to dynamic (DYN and isometric contractions (ISO at a similar, low heart rate (HR level. Therefore, 22 healthy males (26.7 ± 3.6 yrs performed two kinds of voluntary exercises at similar HR: ISO and DYN of the right quadriceps femoris muscle. Although HR was eqivalent (82 ± 8 bpm for DYN and ISO, respectively, rating of exertion, blood pressures, and rate pressure product were higher, whereas breathing frequency, minute ventilation, oxygen uptake and carbon dioxide output were significantly lower during ISO. Tidal volume, end-tidal partial pressures of O2 and CO2, respiratory exchange ratio and capillary blood lactate concentration were comparable between both contraction modes. Heart rate variability (HRV indicators, SDNN, HF-Power and LF-Power, representing both vagal and sympathetic influences, were significantly higher during ISO. Sample entropy, a nonlinear measure of HRV was also significantly affected by contraction mode. It can be concluded that, despite the same net effect on HR, the quality of cardiovascular control during low intensity exercise is significantly different between DYN and ISO. HRV analysis indicated a sympatho-vagal coactivation during ISO. Whether mechanoreceptor feedback alone, a change in central command, or the interaction of both mechanisms is the main contributor of the distinct autonomic responses to the different exercise modes remains to be elucidated.

  12. Mesenchymal Stem Cells Improve Heart Rate Variability and Baroreflex Sensitivity in Rats with Chronic Heart Failure

    Science.gov (United States)

    de Morais, Sharon Del Bem Velloso; da Silva, Luiz Eduardo Virgilio; Lataro, Renata Maria; Silva, Carlos Alberto Aguiar; de Oliveira, Luciano Fonseca Lemos; de Carvalho, Eduardo Elias Vieira; Simões, Marcus Vinicius; da Silva Meirelles, Lindolfo; Fazan, Rubens

    2015-01-01

    Heart failure induced by myocardial infarct (MI) attenuates the heart rate variability (HRV) and baroreflex sensitivity, which are important risk factors for life-threatening cardiovascular events. Therapies with mesenchymal stem cells (MSCs) have shown promising results after MI. However, the effects of MSCs on hemodynamic (heart rate and arterial pressure) variability and baroreflex sensitivity in chronic heart failure (CHF) following MI have not been evaluated thus far. Male Wistar rats received MSCs or saline solution intravenously 1 week after ligation of the left coronary artery. Control (noninfarcted) rats were also evaluated. MI size was assessed using single-photon emission computed tomography (SPECT). The left ventricular ejection fraction (LVEF) was evaluated using radionuclide ventriculography. Four weeks after MSC injection, the animals were anesthetized and instrumented for chronic ECG recording and catheters were implanted in the femoral artery to record arterial pressure. Arterial pressure and HRVs were determined in time and frequency domain (spectral analysis) while HRV was also examined using nonlinear methods: DFA (detrended fluctuation analysis) and sample entropy. The initial MI size was the same among all infarcted rats but was reduced by MSCs. CHF rats exhibited increased myocardial interstitial collagen and sample entropy combined with the attenuation of the following cardiocirculatory parameters: DFA indices, LVEF, baroreflex sensitivity, and HRV. Nevertheless, MSCs hampered all these alterations, except the LVEF reduction. Therefore, 4 weeks after MSC therapy was applied to CHF rats, MI size and myocardial interstitial fibrosis decreased, while baroreflex sensitivity and HRV improved. PMID:26059001

  13. Assessment of post-laparotomy pain in laboratory mice by telemetric recording of heart rate and heart rate variability

    Directory of Open Access Journals (Sweden)

    Kasermann Hans P

    2007-08-01

    Full Text Available Abstract Background Pain of mild to moderate grade is difficult to detect in laboratory mice because mice are prey animals that attempt to elude predators or man by hiding signs of weakness, injury or pain. In this study, we investigated the use of telemetry to identify indicators of mild-to-moderate post-laparotomy pain. Results Adult mice were subjected to laparotomy, either combined with pain treatment (carprofen or flunixin, 5 mg/kg s/c bid, for 1 day or without pain relief. Controls received anesthesia and analgesics or vehicle only. Telemetrically measured locomotor activity was undisturbed in all animals, thus confirming that any pain experienced was of the intended mild level. No symptoms of pain were registered in any of the groups by scoring the animals' outer appearance or spontaneous and provoked behavior. In contrast, the group receiving no analgesic treatment after laparotomy demonstrated significant changes in telemetry electrocardiogram recordings: increased heart rate and decreased heart rate variability parameters pointed to sympathetic activation and pain lasting for 24 hours. In addition, core body temperature was elevated. Body weight and food intake were reduced for 3 and 2 days, respectively. Moreover, unstructured cage territory and destroyed nests appeared for 1–2 days in an increased number of animals in this group only. In controls these parameters were not affected. Conclusion In conclusion, real-time telemetric recordings of heart rate and heart rate variability were indicative of mild-to-moderate post-laparotomy pain and could define its duration in our mouse model. This level of pain cannot easily be detected by direct observation.

  14. Assessment of post-laparotomy pain in laboratory mice by telemetric recording of heart rate and heart rate variability

    Science.gov (United States)

    Arras, Margarete; Rettich, Andreas; Cinelli, Paolo; Kasermann, Hans P; Burki, Kurt

    2007-01-01

    Background Pain of mild to moderate grade is difficult to detect in laboratory mice because mice are prey animals that attempt to elude predators or man by hiding signs of weakness, injury or pain. In this study, we investigated the use of telemetry to identify indicators of mild-to-moderate post-laparotomy pain. Results Adult mice were subjected to laparotomy, either combined with pain treatment (carprofen or flunixin, 5 mg/kg s/c bid, for 1 day) or without pain relief. Controls received anesthesia and analgesics or vehicle only. Telemetrically measured locomotor activity was undisturbed in all animals, thus confirming that any pain experienced was of the intended mild level. No symptoms of pain were registered in any of the groups by scoring the animals' outer appearance or spontaneous and provoked behavior. In contrast, the group receiving no analgesic treatment after laparotomy demonstrated significant changes in telemetry electrocardiogram recordings: increased heart rate and decreased heart rate variability parameters pointed to sympathetic activation and pain lasting for 24 hours. In addition, core body temperature was elevated. Body weight and food intake were reduced for 3 and 2 days, respectively. Moreover, unstructured cage territory and destroyed nests appeared for 1–2 days in an increased number of animals in this group only. In controls these parameters were not affected. Conclusion In conclusion, real-time telemetric recordings of heart rate and heart rate variability were indicative of mild-to-moderate post-laparotomy pain and could define its duration in our mouse model. This level of pain cannot easily be detected by direct observation. PMID:17683523

  15. Smartphone accelerometers for the detection of heart rate.

    Science.gov (United States)

    Landreani, Federica; Caiani, Enrico Gianluca

    2017-12-01

    Micro-electro-mechanical systems technology, now embedded into smartphones, potentially allows measuring heart mechanical activity by positioning the phone on the body and acquiring vibrational signals, without the need for additional peripherals or interfaces. However, lack of standardization in experimental protocol, processing methodology and validation procedures, together with the wide range of available smartphones on the market, impact on the comparability of results and their general validity. The aim of this review is to provide information on the state-of-the art of research in this field, with current limitations and potentials, thus potentially serving as a basis for the creation of a standard based on current experiences. Areas covered: The review focused on studies relevant to the extraction of the heart rate using accelerometric technology, searching for relevant literature (papers or conference proceedings) both in Pubmed and IEEE eXplore engines. Expert commentary: From the results of this review, the smartphone can be considered a powerful device able to accurately measure the resting heart rate, thanks to embedded accelerometer technology. However, lack of a shared standard in the acquisition protocol and analysis procedure, thus affecting user-collected data reliability, could limit clinical acceptability and prevent recommending this approach as a self-tracking tool in patients.

  16. Heart rate turbulence and variability in patients with ventricular arrhythmias

    Directory of Open Access Journals (Sweden)

    Diego Tarricone

    2009-08-01

    Full Text Available Background: To evaluate the changes in autonomic neural control mechanisms before malignant ventricular arrhythmias, we measured heart rate variability (HRV and heart rate turbulence (HRT in patients with ventricular tachycardia or fibrillation (Group I; n=6, non sustained ventricular tachycardia (Group II; n=32, frequent premature ventricular beats (Group III; n=26 and with ICD implantation (Group IV; n=11. Methods: Time domain parameters of HRV and turbulence onset (TO and slope (TS were calculated on 24 hour Holter recordings. Normal values were: SDNN > 70 msec for HRV, TO <0% and TS >2.5 msec/RR-I for HRT. Results: Whereas SDNN was within normal range and similar in all study groups, HRT parameters were significantly different in patients who experienced VT/VF during Holter recording. Abnormal TO and/or TS were present in 100% of Group I patients and only in about 50% of Group II and IV. On the contrary, normal HRT parameters were present in 40-70% of Group II, III and IV patients and none of Group I. Conclusions: These data suggest that HRT analysis is more suitable than HRV to detect those transient alterations in autonomic control mechanisms that are likely to play a major trigger role in the genesis of malignant cardiac arrhythmias. (Heart International 2007; 3: 51-7

  17. Design and validation of a knee brace with feedback to reduce the rate of loading.

    Science.gov (United States)

    Riskowski, J L; Mikesky, A E; Bahamonde, R E; Burr, D B

    2009-08-01

    The repetitive nature of walking can lead to repetitive stress and associated complications due to the rate of loading (ROL) experienced by the body at the initial contact of the foot with the ground. An individual's gait kinematics at initial contact has been suggested to give rise to the ROL, and a repetitive, high ROL may lead to several disorders, including osteoarthritis. We present the design, development, and validation of a knee brace that provides feedback to the user during gait. The feedback consists of an auditory signal when the specific parameters of knee angle or tibial acceleration 50 ms prior to contact are exceeded. Nine women were recruited for the gait analysis, and the gait characteristics with and without the brace and feedback are analyzed. Our results indicate that using a knee brace with feedback can effectively change the gait kinematics used during walking, leading to a reduced ROL experienced at initial contact. Using a knee brace with feedback is a novel approach to gait retraining. Al-though the kinetics of how the subjects change in gait pattern is unknown, the reduced ROL experienced is significant and warrants further investigation.

  18. Mosquito aging modulates the heart rate and the proportional directionality of heart contractions.

    Science.gov (United States)

    Doran, Charlotte R; Estévez-Lao, Tania Y; Hillyer, Julián F

    2017-08-01

    Mosquito aging impacts a myriad of physiological processes, including digestion, flight, mating, reproductive success, and immunity. In the present study, we conducted intravital video imaging in 1, 3, 5, 10, 15 and 20-day-old Anopheles gambiae female adults to assess whether aging impacts mosquito heart physiology. We found that the heart contraction rate increases over the first 15days of adulthood and then decreases. These changes occur for both contraction directions, although aging results in a relative change in the anterograde versus retrograde contraction rates. That is, whereas for the first 5days of life the anterograde and retrograde contraction rates are similar, from day 10 to day 20 the retrograde contraction rate is higher than the anterograde contraction rate. Aging also biases the proportional directionality of heart contractions, from approximately two thirds of the time being spent contracting in the anterograde direction and two thirds of the contractions propagating anterograde during the first 5days of life to an approximately even split between anterograde and retrograde when the mosquitoes have reached 10 to 20days of age. Transcriptional analyses of crustacean cardioactive peptide (CCAP), FMRFamide, calcium-calmodulin dependent kinase II (CaMKII), pygopus, manganese-iron superoxide dismutase (MnSOD1) and vinculin by quantitative RT-PCR revealed age-associated changes in gene expression, with MnSOD1 and vinculin expression showing a declining trend with age. RNAi-based knockdown of MnSOD1 or vinculin resulted in heart physiology that trended toward the aging phenotype for every parameter that was measured, suggesting that these two genes are involved in cardiac aging. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Heritability of cardiac vagal control in 24-h heart rate variability recordings: influence of ceiling effects at low heart rates.

    Science.gov (United States)

    Neijts, Melanie; Van Lien, Rene; Kupper, Nina; Boomsma, Dorret; Willemsen, Gonneke; de Geus, Eco J C

    2014-10-01

    This study estimated the heritability of 24-h heart rate variability (HRV) measures, while considering ceiling effects on HRV at low heart rates during the night. HRV was indexed by the standard deviation of all valid interbeat intervals (SDNN), the root mean square of differences between valid, successive interbeat intervals (RMSSD), and peak-valley respiratory sinus arrhythmia (pvRSA). Sleep and waking levels of cardiac vagal control were assessed in 1,003 twins and 285 of their non-twin siblings. Comparable heritability estimates were found for SDNN (46%-53%), RMSSD (49%-54%), and pvRSA (48%-57%) during the day and night. A nighttime ceiling effect was revealed in 10.7% of participants by a quadratic relationship between mean pvRSA and the interbeat interval. Excluding these participants did not change the heritability estimates. The genetic factors influencing ambulatory pvRSA, RMSSD, and SDNN largely overlap. These results suggest that gene-finding studies may pool the different cardiac vagal indices and that exclusion of participants with low heart rates is not required. Copyright © 2014 Society for Psychophysiological Research.

  20. Respiratory modulation and baroreflex control of heart rate in space

    Science.gov (United States)

    Verheyden, Bart; Couckuyt, Kurt; Liu, Jiexin; Aubert, Andre

    During everyday life, gravity constantly stresses the human circulation by diminishing venous return in the upright position. This induces baroreflex-mediated cardiovascular adjustments that are aimed to prevent the blood pressure from falling. In weightlessness, gravitational pressure gradients do not arise in the circulation so that baroreflex function remains chronically unchallenged. This may contribute to the development of post spaceflight orthostatic intolerance. The purpose of this study was to evaluate respiratory modulation and baroreflex control of heart rate after a week of weightlessness in space. We tested the hypothesis that cardiovascular control in space will be similar to the baseline supine condition on Earth. We studied nine male cosmonauts during seven different space missions aboard the ISS (age 40 - 52 yrs, height 1.69 - 1.85 m, weight 67 - 90 kg). Data collection was performed between 30 and 45 days before launch in the standing and supine positions, and after 8 days in space. Cosmonauts were carefully trained to perform in-flight data collection by themselves. They were instructed to pace their breathing to a fixed rate of 12 breaths per minute (0.2 Hz) for a total duration of 3 minutes. The electrocardiogram and beat-by-beat finger arterial blood pressure were recorded at 1-kHz sample rate. Respiratory rate was evaluated using an abdominal pressure sensor. We used power spectral analysis to calculate respiratory sinus arrhythmia (RSA) as well as the low-frequency (0.04 - 0.15 Hz) powers of spontaneous oscillations in heart rate and systolic blood pressure. Baroreflex sensitivity (BRS) was estimated in the time domain using cross-correlation analysis. As expected, there was a rise in heart rate upon assuming the standing position before space- flight (59 ± 6 to 79 ± 11 beats per min; p ¡ 0.001). This was accompanied by an increase in mean arterial blood pressure (84 ± 6 to 93 ± 6 mmHg; p ¡ 0.001). Standing up further induced a marked

  1. Exploring the impact of feedback on prescribing error rates: a pilot study.

    Science.gov (United States)

    Lloyd, Michael; Watmough, Simon David; O'Brien, Sarah Victoria; Hardy, Kevin; Furlong, Niall

    2017-10-01

    Background Prescribing errors are prevalent in hospital settings with feedback identified as one potential error reduction strategy. Hospital pharmacists work alongside prescribers at ward level and are credible facilitators of prescribing error feedback. A formalised programme of pharmacist-led prescribing error feedback was designed and implemented Objective To determine the impact of the feedback intervention on prescribing error rates. Method Prospective prescribing audits were undertaken at baseline for control (n = 11) and intervention group (n = 10) prescribers. The intervention group received pharmacist-led, individualised constructive feedback on their prescribing, whilst the control group continued with existing practice. Prescribing was re-audited following 3-months of the intervention. Data were analysed using chi-squared and independent t-tests. Results Error frequency (123/641 intervention and 121/649 control) was comparable between groups at baseline (p = 0.819) with significant differences (90/1677 intervention and 236/984 control) post intervention (p = <0.005). Prescribing error rates were lower in the intervention group (mean change of -11.5%) and higher in the control group (mean change of +5.9%) following the intervention, with a mean significant difference of 17.4% (SD 4.7, 95% CI, -27.3 to -7.6), t = -3.694, p < 0.05, between groups. Conclusion Pharmacist-led prescribing error feedback positively influences prescribing. This intervention shows promise for wider application in hospital settings to optimise patient safety.

  2. Audit and feedback using the Robson classification to reduce caesarean section rates: a systematic review.

    Science.gov (United States)

    Boatin, A A; Cullinane, F; Torloni, M R; Betrán, A P

    2018-01-01

    In most regions worldwide, caesarean section (CS) rates are increasing. In these settings, new strategies are needed to reduce CS rates. To identify, critically appraise and synthesise studies using the Robson classification as a system to categorise and analyse data in clinical audit cycles to reduce CS rates. Medline, Embase, CINAHL and LILACS were searched from 2001 to 2016. Studies reporting use of the Robson classification to categorise and analyse data in clinical audit cycles to reduce CS rates. Data on study design, interventions used, CS rates, and perinatal outcomes were extracted. Of 385 citations, 30 were assessed for full text review and six studies, conducted in Brazil, Chile, Italy and Sweden, were included. All studies measured initial CS rates, provided feedback and monitored performance using the Robson classification. In two studies, the audit cycle consisted exclusively of feedback using the Robson classification; the other four used audit and feedback as part of a multifaceted intervention. Baseline CS rates ranged from 20 to 36.8%; after the intervention, CS rates ranged from 3.1 to 21.2%. No studies were randomised or controlled and all had a high risk of bias. We identified six studies using the Robson classification within clinical audit cycles to reduce CS rates. All six report reductions in CS rates; however, results should be interpreted with caution because of limited methodological quality. Future trials are needed to evaluate the role of the Robson classification within audit cycles aimed at reducing CS rates. Use of the Robson classification in clinical audit cycles to reduce caesarean rates. © 2017 The Authors. BJOG An International Journal of Obstetrics and Gynaecology published by John Wiley & Sons Ltd on behalf of Royal College of Obstetricians and Gynaecologists.

  3. Heart rate responses to autonomic challenges in obstructive sleep apnea.

    Directory of Open Access Journals (Sweden)

    Paul M Macey

    Full Text Available Obstructive sleep apnea (OSA is accompanied by structural alterations and dysfunction in central autonomic regulatory regions, which may impair dynamic and static cardiovascular regulation, and contribute to other syndrome pathologies. Characterizing cardiovascular responses to autonomic challenges may provide insights into central nervous system impairments, including contributions by sex, since structural alterations are enhanced in OSA females over males. The objective was to assess heart rate responses in OSA versus healthy control subjects to autonomic challenges, and, separately, characterize female and male patterns. We studied 94 subjects, including 37 newly-diagnosed, untreated OSA patients (6 female, age mean ± std: 52.1 ± 8.1 years; 31 male aged 54.3 ± 8.4 years, and 57 healthy control subjects (20 female, 50.5 ± 8.1 years; 37 male, 45.6 ± 9.2 years. We measured instantaneous heart rate with pulse oximetry during cold pressor, hand grip, and Valsalva maneuver challenges. All challenges elicited significant heart rate differences between OSA and control groups during and after challenges (repeated measures ANOVA, p<0.05. In post-hoc analyses, OSA females showed greater impairments than OSA males, which included: for cold pressor, lower initial increase (OSA vs. control: 9.5 vs. 7.3 bpm in females, 7.6 vs. 3.7 bpm in males, OSA delay to initial peak (2.5 s females/0.9 s males, slower mid-challenge rate-of-increase (OSA vs. control: -0.11 vs. 0.09 bpm/s in females, 0.03 vs. 0.06 bpm/s in males; for hand grip, lower initial peak (OSA vs. control: 2.6 vs. 4.6 bpm in females, 5.3 vs. 6.0 bpm in males; for Valsalva maneuver, lower Valsalva ratio (OSA vs. control: 1.14 vs. 1.30 in females, 1.29 vs. 1.34 in males, and OSA delay during phase II (0.68 s females/1.31 s males. Heart rate responses showed lower amplitude, delayed onset, and slower rate changes in OSA patients over healthy controls, and impairments may be more pronounced in

  4. Newborn infant pain assessment using heart rate variability analysis.

    Science.gov (United States)

    Faye, Papa M; De Jonckheere, Julien; Logier, Regis; Kuissi, Eliane; Jeanne, Mathieu; Rakza, Thameur; Storme, Laurent

    2010-01-01

    Systems controlling cardiovascular function are closely coupled with the perception of pain. Heart rate variability (HRV) is a well-established noninvasive measure of cardiac autonomic control. We hypothesized that pain may alter HRV in the newborn infant and that HRV analysis could be used as an indicator of prolonged pain in the newborn infant. To test the hypothesis, we measured the magnitude of the heart rate high-frequency variations using an innovative High Frequency Variability Index (HFVI) in newborn infants at risk of postoperative pain. We investigated newborn infants with a gestational age (GA) more than 34 weeks, and who were admitted after a major surgical procedure. Inclusions ranged from 2 to 72 hours after the surgery. The postoperative pain was scored using EDIN scale (neonatal pain and discomfort scale) at the end of the 2 hours recording period. The infants were separated in: (1) Group "Low EDIN," when EDIN=5. Predictive positive and negative values of a threshold value of HFVI in assessing pain have been studied. Twenty-eight newborn infants were enrolled in the study (mean GA=37.8+/-1.5 wk) at a median delay between the surgery and the recording of 5 hours. Mean EDIN were 2+/-1 and 7+/-2 in respectively the groups "Low EDIN" and "High EDIN." The 2 groups were similar for GA, basal heart and respiratory rates, SpO2, mean arterial blood pressure, and morphine infusion rate. HFVI was significantly lower in the group "High EDIN" than in the group "Low EDIN" (0.7+/-0.2 vs. 1.2+/-0.3, respectively; P=5, with a sensitivity of 90%, and a specificity of 75%. The results of this study indicate that postoperative pain is associated with a decreased high-frequency HRV in full-term newborn infants. Our findings suggest that HRV could be used as an indicator to assess prolonged pain in the newborn infants.

  5. Loss of lag-response curvilinearity of indices of heart rate variability in congestive heart failure

    Science.gov (United States)

    Thakre, Tushar P; Smith, Michael L

    2006-01-01

    Background Heart rate variability (HRV) is known to be impaired in patients with congestive heart failure (CHF). Time-domain analysis of ECG signals traditionally relies heavily on linear indices of an essentially non-linear phenomenon. Poincaré plots are commonly used to study non-linear behavior of physiologic signals. Lagged Poincaré plots incorporate autocovariance information and analysis of Poincaré plots for various lags can provide interesting insights into the autonomic control of the heart. Methods Using Poincaré plot analysis, we assessed whether the relation of the lag between heart beats and HRV is altered in CHF. We studied the influence of lag on estimates of Poincaré plot indices for various lengths of beat sequence in a public domain data set (PhysioNet) of 29 subjects with CHF and 54 subjects with normal sinus rhythm. Results A curvilinear association was observed between lag and Poincaré plot indices (SD1, SD2, SDLD and SD1/SD2 ratio) in normal subjects even for a small sequence of 50 beats (p value for quadratic term 3 × 10-5, 0.002, 3.5 × 10-5 and 0.0003, respectively). This curvilinearity was lost in patients with CHF even after exploring sequences up to 50,000 beats (p values for quadratic term > 0.5). Conclusion Since lagged Poincaré plots incorporate autocovariance information, these analyses provide insights into the autonomic control of heart rate that is influenced by the non-linearity of the signal. The differences in lag-response in CHF patients and normal subjects exist even in the face of the treatment received by the CHF patients. PMID:16768800

  6. Loss of lag-response curvilinearity of indices of heart rate variability in congestive heart failure

    Directory of Open Access Journals (Sweden)

    Smith Michael L

    2006-06-01

    Full Text Available Abstract Background Heart rate variability (HRV is known to be impaired in patients with congestive heart failure (CHF. Time-domain analysis of ECG signals traditionally relies heavily on linear indices of an essentially non-linear phenomenon. Poincaré plots are commonly used to study non-linear behavior of physiologic signals. Lagged Poincaré plots incorporate autocovariance information and analysis of Poincaré plots for various lags can provide interesting insights into the autonomic control of the heart. Methods Using Poincaré plot analysis, we assessed whether the relation of the lag between heart beats and HRV is altered in CHF. We studied the influence of lag on estimates of Poincaré plot indices for various lengths of beat sequence in a public domain data set (PhysioNet of 29 subjects with CHF and 54 subjects with normal sinus rhythm. Results A curvilinear association was observed between lag and Poincaré plot indices (SD1, SD2, SDLD and SD1/SD2 ratio in normal subjects even for a small sequence of 50 beats (p value for quadratic term 3 × 10-5, 0.002, 3.5 × 10-5 and 0.0003, respectively. This curvilinearity was lost in patients with CHF even after exploring sequences up to 50,000 beats (p values for quadratic term > 0.5. Conclusion Since lagged Poincaré plots incorporate autocovariance information, these analyses provide insights into the autonomic control of heart rate that is influenced by the non-linearity of the signal. The differences in lag-response in CHF patients and normal subjects exist even in the face of the treatment received by the CHF patients.

  7. Association between atrial fibrillatory rate and heart rate variability in patients with atrial fibrillation and congestive heart failure.

    Science.gov (United States)

    Corino, Valentina D A; Cygankiewicz, Iwona; Mainardi, Luca T; Stridh, Martin; Vasquez, Rafael; Bayes de Luna, Antonio; Holmqvist, Fredrik; Zareba, Wojciech; Platonov, Pyotr G

    2013-01-01

    Even if atrial fibrillatory rate (AFR) has been related to clinical outcome in patients with atrial fibrillation (AF), its relation with ventricular response has not been deeply studied. The aim of this study was to investigate the relation between AFR and RR series variability in patients with AF. Twenty-minute electrocardiograms in orthogonal leads were processed to extract AFR, using spatiotemporal QRST cancellation and time frequency analysis, and RR series in 127 patients (age 69 ± 11 years) with congestive heart failure (NYHA II-III) enrolled in the MUSIC study (MUerte Subita en Insufficiencia Cardiaca). Heart rate variability and irregularity were assessed by time domain parameters and entropy-based indices, respectively and their correlation with AFR investigated. Variability measures seem not to be related to AFR, while irregularity measures do. A significant correlation between AFR and variability parameters of heart rate variability during AF was found only in patients not treated with antiarrhythmics drugs (correlation = 0.56 P < 0.05 for pNN50), while this correlation was lost in patients taking rate- or rhythm-control drugs. A significant positive correlation between AFR and indices of RR irregularity was found, showing that a higher AFR is related to a less organized RR series (correlation = 0.33 P < 0.05 for regularity index for all patients, correlation increased in subgroups of patients treated with the same drug). These results suggest that a higher AFR is associated with a higher degree of irregularity of ventricular response that is observed regardless of the use of rate-controlling drugs. ©2012, Wiley Periodicals, Inc.

  8. Heart rate turbulence predicts all-cause mortality and sudden death in congestive heart failure patients.

    Science.gov (United States)

    Cygankiewicz, Iwona; Zareba, Wojciech; Vazquez, Rafael; Vallverdu, Montserrat; Gonzalez-Juanatey, Jose R; Valdes, Mariano; Almendral, Jesus; Cinca, Juan; Caminal, Pere; de Luna, Antoni Bayes

    2008-08-01

    Abnormal heart rate turbulence (HRT) has been documented as a strong predictor of total mortality and sudden death in postinfarction patients, but data in patients with congestive heart failure (CHF) are limited. The aim of this study was to evaluate the prognostic significance of HRT for predicting mortality in CHF patients in New York Heart Association (NYHA) class II-III. In 651 CHF patients with sinus rhythm enrolled into the MUSIC (Muerte Subita en Insuficiencia Cardiaca) study, the standard HRT parameters turbulence onset (TO) and slope (TS), as well as HRT categories, were assessed for predicting total mortality and sudden death. HRT was analyzable in 607 patients, mean age 63 years (434 male), 50% of ischemic etiology. During a median follow up of 44 months, 129 patients died, 52 from sudden death. Abnormal TS and HRT category 2 (HRT2) were independently associated with increased all-cause mortality (HR: 2.10, CI: 1.41 to 3.12, P 120 ms. HRT is a potent risk predictor for both heart failure and arrhythmic death in patients with class II and III CHF.

  9. Comparison of heart rate and external performance at selected field tests for determining maximum heart rate for bicyclists and triathletes when cycling.

    OpenAIRE

    Podrazil, Tomáš

    2014-01-01

    Title: Comparison of the heart rate values and external performance is based on selected field tests determining maximal heart rate in cycling of cyclist and triathletes Objectives: Objective of thesis is to determine the values of maximal heart rate and external performance from selected field tests in cycling and compare them with one another. Methods: Three cyclist were measured in field tests and acquired results were used to create the graphs and tables. Data were obtained by cycling per...

  10. Omega-3 Polyunsaturated Fatty Acids and Heart Rate Variability

    Directory of Open Access Journals (Sweden)

    Jeppe Hagstrup Christensen

    2011-11-01

    Full Text Available Omega-3 polyunsaturated fatty acids (PUFA may modulate autonomic control of the heart because omega-3 PUFA is abundant in the brain and other nervous tissue as well as in cardiac tissue. This might partly explain why omega-3 PUFA offer some protection against sudden cardiac death (SCD. The autonomic nervous system is involved in the pathogenesis of SCD. Heart rate variability (HRV can be used as a non-invasive marker of cardiac autonomic control and a low HRV is a predictor for SCD and arrhythmic events. Studies on HRV and omega-3 PUFA have been performed in several populations such as patients with ischemic heart disease, patients with diabetes mellitus, patients with chronic renal failure, and in healthy subjects as well as in children.. The studies have demonstrated a positive association between cellular content of omega-3 PUFA and HRV and supplementation with omega-3 PUFA seems to increase HRV which could be a possible explanation for decreased risk of arrhythmic events and SCD sometimes observed after omega-3 PUFA supplementation. However, the results are not consistent and further research is needed

  11. Optimum Heart Rate to Minimize Pulsatile External Cardiac Power

    Science.gov (United States)

    Pahlevan, Niema; Gharib, Morteza

    2011-11-01

    The workload on the left ventricle is composed of steady and pulsatile components. Clinical investigations have confirmed that an abnormal pulsatile load plays an important role in the pathogenesis of left ventricular hypertrophy (LVH) and progression of LVH to congestive heart failure (CHF). The pulsatile load is the result of the complex dynamics of wave propagation and reflection in the compliant arterial vasculature. We hypothesize that aortic waves can be optimized to reduce the left ventricular (LV) pulsatile load. We used an in-vitro experimental approach to investigate our hypothesis. A unique hydraulic model was used for in-vitro experiments. This model has physical and dynamical properties similar to the heart-aorta system. Different compliant models of the artificial aorta were used to test the hypothesis under various aortic rigidities. Our results indicate that: i) there is an optimum heart rate that minimizes LV pulsatile power (this is in agreement with our previous computational study); ii) introducing an extra reflection site at the specific location along the aorta creates constructive wave conditions that reduce the LV pulsatile power.

  12. A novel modality for intrapartum fetal heart rate monitoring.

    Science.gov (United States)

    Ashwal, Eran; Shinar, Shiri; Aviram, Amir; Orbach, Sharon; Yogev, Yariv; Hiersch, Liran

    2017-11-02

    Intrapartum fetal heart rate (FHR) monitoring is well recommended during labor to assess fetal wellbeing. Though commonly used, the external Doppler and fetal scalp electrode monitor have significant shortcomings. Lately, non-invasive technologies were developed as possible alternatives. The objective of this study is to compare the accuracy of FHR trace using novel Electronic Uterine Monitoring (EUM) to that of external Doppler and fetal scalp electrode monitor. A comparative study conducted in a single tertiary medical center. Intrapartum FHR trace was recorded simultaneously using three different methods: internal fetal scalp electrode, external Doppler, and EUM. The latter, a multichannel electromyogram (EMG) device acquires a uterine signal and maternal and fetal electrocardiograms. FHR traces obtained from all devices during the first and second stages of labor were analyzed. Positive percent of agreement (PPA) and accuracy (by measuring root means square error between observed and predicted values) of EUM and external Doppler were both compared to internal scalp electrode monitoring. A Bland-Altman agreement plot was used to compare the differences in FHR trace between all modalities. For momentary recordings of fetal heart rate 160 bpm level of agreement, sensitivity, and specificity were also evaluated. Overall, 712,800 FHR momentary recordings were obtained from 33 parturients. Although both EUM and external Doppler highly correlated with internal scalp electrode monitoring (r2 = 0.98, p fetal heart rate 160 bpm, the PPA, sensitivity, and specificity of EUM as compared with internal fetal scalp electrode, were significantly greater than those of external Doppler (p monitoring than external Doppler. As such, it may provide a good framework for non-invasive evaluation of intrapartum FHR.

  13. Fetal heart rate monitoring: from Doppler to computerized analysis.

    Science.gov (United States)

    Kwon, Ji Young; Park, In Yang

    2016-03-01

    The monitoring of fetal heart rate (FHR) status is an important method to check well-being of the baby during labor. Since the electronic FHR monitoring was introduced 40 years ago, it has been expected to be an innovative screening test to detect fetuses who are becoming hypoxic and who may benefit from cesarean delivery or operative vaginal delivery. However, several randomized controlled trials have failed to prove that electronic FHR monitoring had any benefit of reducing the perinatal mortality and morbidity. Also it is now clear that the FHR monitoring had high intra- and interobserver disagreements and increased the rate of cesarean delivery. Despite such limitations, the FHR monitoring is still one of the most important obstetric procedures in clinical practice, and the cardiotocogram is the most-used equipment. To supplement cardiotocogram, new methods of computerized FHR analysis and electrocardiogram have been developed, and several clinical researches have been currently performed. Computerized equipment makes us to analyze beat-to-beat variability and short term heart rate patterns. Furthermore, researches about multiparameters of FHR variability will be ongoing.

  14. Caffeine Enhances Heart Rate Variability in Middle-Aged Healthy, But Not Heart Failure Subjects.

    Science.gov (United States)

    Notarius, Catherine F; Floras, John S

    2012-06-01

    In chronic heart failure (CHF) due to left ventricular dysfunction, diminished heart rate variability (HRV) is an independent predictor of poor prognosis. Caffeine has been shown to increase HRV in young healthy subjects. Such an increase may be of potential benefit to patients with CHF. We hypothesized that intravenous infusion of caffeine would increase HRV in CHF, and in age-matched healthy control subjects. On two separate days, 11 patients (1F) with CHF (age=51.3±4.6 years; left ventricular ejection fraction=18.6±2.7%; mean±standard error) and 10 healthy control subjects (age=48.0±4.0) according to a double-blind randomization design, received either saline or caffeine (4 mg/kg) infusion. We assessed HRV over 7 minutes of supine rest (fast Fourier Transform analysis) to determine total spectral power as well as its high-frequency (HF) (0.15-0.50 Hz) and low-frequency (LF) (0.05-0.15 Hz) components, and recorded muscle sympathetic nerve activity (MSNA) directly from the peroneal nerve (microneurography). In healthy control subjects, compared with saline, caffeine reduced both heart rate and sympathetic nerve traffic (p≤0.003) and increased the ratio of HF/total power (p≤0.05). Baseline LF power and the ratio LF/HF were significantly lower in CHF compared with controls (p=0.02), but caffeine had no effect on any element of HRV. Caffeine increases cardiac vagal heart rate modulation and reduces MSNA in middle-aged healthy subjects, but not in those with CHF.

  15. Impact of training load on the heart rate of horses

    OpenAIRE

    Eva Mlyneková; Marko Halo; Miroslav Maršálek; Lucie Starostová

    2016-01-01

    In our work, we analyzed the effect of training load on the heart rate of horses in a simulated load by the loading regulator for horse motion Horse Gym 2000. In the experiment were observed 8 Slovak Warmblood horses (3 mares, 4 geldings, 1 stallion) aged 6-10 years. The experiment was divided into two parts after three weeks. The speed of the tested horses was 4.9 km/h in the first part of experiment, in the second part was the speed 5.2 km/h with a gradual uphill up to 7 %. The tested horse...

  16. Neural Network Analysis and Evaluation of the Fetal Heart Rate

    Directory of Open Access Journals (Sweden)

    Yasuaki Noguchi

    2009-01-01

    Full Text Available The aim of the present study is to obtain a highly objective automatic fetal heart rate (FHR diagnosis. The neural network software was composed of three layers with the back propagation, to which 8 FHR data, including sinusoidal FHR, were input and the system was educated by the data of 20 cases with a known outcome. The output was the probability of a normal, intermediate, or pathologic outcome. The neural index studied prolonged monitoring. The neonatal states and the FHR score strongly correlated with the outcome probability. The neural index diagnosis was correct. The completed software was transferred to other computers, where the system function was correct.

  17. Simulation of heart rate variability model in a network

    Science.gov (United States)

    Cascaval, Radu C.; D'Apice, Ciro; D'Arienzo, Maria Pia

    2017-07-01

    We consider a 1-D model for the simulation of the blood flow in the cardiovascular system. As inflow condition we consider a model for the aortic valve. The opening and closing of the valve is dynamically determined by the pressure difference between the left ventricular and aortic pressures. At the outflow we impose a peripheral resistance model. To approximate the solution we use a numerical scheme based on the discontinuous Galerkin method. We also considering a variation in heart rate and terminal reflection coefficient due to monitoring of the pressure in the network.

  18. Heart rate and estimated energy expenditure during ballroom dancing.

    Science.gov (United States)

    Blanksby, B A; Reidy, P W

    1988-01-01

    Ten competitive ballroom dance couples performed simulated competitive sequences of Modern and Latin American dance. Heart rate was telemetered during the dance sequences and related to direct measures of oxygen uptake and heart rate obtained while walking on a treadmill. Linear regression was employed to estimate gross and net energy expenditures of the dance sequences. A multivariate analysis of variance with repeated measures on the dance factor was applied to the data to test for interaction and main effects on the sex and dance factors. Overall mean heart rate values for the Modern dance sequence were 170 beats.min-1 and 173 beats.min-1 for males and females respectively. During the Latin American sequence mean overall heart rate for males was 168 beats.min-1 and 177 beats.min-1 for females. Predicted mean gross values of oxygen consumption for the males were 42.8 +/- 5.7 ml.kg-1 min-1 and 42.8 +/- 6.9 ml.kg-1 min-1 for the Modern and Latin American sequences respectively. Corresponding gross estimates of oxygen consumption for the females were 34.7 +/- 3.8 ml.kg-1 min-1 and 36.1 +/- 4.1 ml.kg-1 min-1. Males were estimated to expand 54.1 +/- 8.1 kJ.min-1 of energy during the Modern sequence and 54.0 +/- 9.6 kJ.min-1 during the Latin American sequence, while predicted energy expenditure for females was 34.7 +/- 3.8 kJ.min-1 and 36.1 +/- 4.1 kJ.min-1 for Modern and Latin American dance respectively. The results suggested that both males and females were dancing at greater than 80% of their maximum oxygen consumption. A significant difference between males and females was observed for predicted gross and net values of oxygen consumption (in L.min-1 and ml.kg-1 min-1). PMID:3167503

  19. A comparative study of pulse rate variability and heart rate variability in healthy subjects.

    Science.gov (United States)

    Wong, Jih-Sen; Lu, Wan-An; Wu, Kung-Tai; Liu, Margaret; Chen, Gau-Yang; Kuo, Cheng-Deng

    2012-04-01

    Both heart rate variability (HRV) and pulse rate variability (PRV) are noninvasive means for the assessment of autonomic nervous control of the heart. However, it is not settled whether or not the PRV obtained from either hand can be the surrogate of HRV. The HRV measures obtained from electrocardiographic signals and the PRV measures obtained from the pulse waves recorded from the index fingers of both hands were compared in normal subjects by using linear regression analysis and Bland and Altman method. Highly significant correlations (P heart rate and ultra-low frequency power (ULFP). The PRV of either hand is close to, but not the same as the HRV in healthy subjects. The HRV, right PRV and left PRV are not surrogates of one another in normal subjects except heart rate and ULFP. Since HRV is generally accepted as the standard method for the assessment of the autonomic nervous modulation of a subject, the PRV of either hand may not be suitable for the assessment of the cardiac autonomic nervous modulation of the subject.

  20. Heart rate effects of intraosseous injections using slow and fast rates of anesthetic solution deposition.

    Science.gov (United States)

    Susi, Louis; Reader, Al; Nusstein, John; Beck, Mike; Weaver, Joel; Drum, Melissa

    2008-01-01

    The authors, using a crossover design, randomly administered, in a single-blind manner, 3 primary intraosseous injections to 61 subjects using: the Wand local anesthetic system at a deposition rate of 45 seconds (fast injection); the Wand local anesthetic system at a deposition rate of 4 minutes and 45 seconds (slow injection); a conventional syringe injection at a deposition rate of 4 minutes and 45 seconds (slow injection), in 3 separate appointments spaced at least 3 weeks apart. A pulse oximeter measured heart rate (pulse). The results demonstrated the mean maximum heart rate was statistically higher with the fast intraosseous injection (average 21 to 28 beats/min increase) than either of the 2 slow intraosseous injections (average 10 to 12 beats/min increase). There was no statistically significant difference between the 2 slow injections. We concluded that an intraosseous injection of 1.4 mL of 2% lidocaine with 1 : 100,000 epinephrine with the Wand at a 45-second rate of anesthetic deposition resulted in a significantly higher heart rate when compared with a 4-minute and 45-second anesthetic solution deposition using either the Wand or traditional syringe.

  1. Heart rate level of golf swing in patients with chronic ischemic heart disease and in healthy controls

    OpenAIRE

    下村, 雅昭; Shimomura, Masaaki; 羽田, 龍彦; Hata, Tatsuhiko; 上村, 桂子; Uemura, Keiko; 廣瀬, 美嘉; Hirose, Mika; 浜崎, 博; Hamazaki, Hiroshi

    2005-01-01

    PURPOSE: To evaluate the effect of golf swing on the heart rate level in patients with chronic ischemic heart disease (IHD) and healthy adults. METHODS: Study subjects were 7 male patients with IHD (mean age 59.3±8.7 years) and 7 age-matched, healthy male golfers. AIl subjects underwent golf swing at driving range, during which heart rate and electrocardiogram were monitored via telemetry system. Blood pressure was taken immediately after each golf swing. RESULTS: The average heart rate value...

  2. Identification of heart rate-associated loci and their effects on cardiac conduction and rhythm disorders.

    Science.gov (United States)

    den Hoed, Marcel; Eijgelsheim, Mark; Esko, Tõnu; Brundel, Bianca J J M; Peal, David S; Evans, David M; Nolte, Ilja M; Segrè, Ayellet V; Holm, Hilma; Handsaker, Robert E; Westra, Harm-Jan; Johnson, Toby; Isaacs, Aaron; Yang, Jian; Lundby, Alicia; Zhao, Jing Hua; Kim, Young Jin; Go, Min Jin; Almgren, Peter; Bochud, Murielle; Boucher, Gabrielle; Cornelis, Marilyn C; Gudbjartsson, Daniel; Hadley, David; van der Harst, Pim; Hayward, Caroline; den Heijer, Martin; Igl, Wilmar; Jackson, Anne U; Kutalik, Zoltán; Luan, Jian'an; Kemp, John P; Kristiansson, Kati; Ladenvall, Claes; Lorentzon, Mattias; Montasser, May E; Njajou, Omer T; O'Reilly, Paul F; Padmanabhan, Sandosh; St Pourcain, Beate; Rankinen, Tuomo; Salo, Perttu; Tanaka, Toshiko; Timpson, Nicholas J; Vitart, Veronique; Waite, Lindsay; Wheeler, William; Zhang, Weihua; Draisma, Harmen H M; Feitosa, Mary F; Kerr, Kathleen F; Lind, Penelope A; Mihailov, Evelin; Onland-Moret, N Charlotte; Song, Ci; Weedon, Michael N; Xie, Weijia; Yengo, Loic; Absher, Devin; Albert, Christine M; Alonso, Alvaro; Arking, Dan E; de Bakker, Paul I W; Balkau, Beverley; Barlassina, Cristina; Benaglio, Paola; Bis, Joshua C; Bouatia-Naji, Nabila; Brage, Søren; Chanock, Stephen J; Chines, Peter S; Chung, Mina; Darbar, Dawood; Dina, Christian; Dörr, Marcus; Elliott, Paul; Felix, Stephan B; Fischer, Krista; Fuchsberger, Christian; de Geus, Eco J C; Goyette, Philippe; Gudnason, Vilmundur; Harris, Tamara B; Hartikainen, Anna-Liisa; Havulinna, Aki S; Heckbert, Susan R; Hicks, Andrew A; Hofman, Albert; Holewijn, Suzanne; Hoogstra-Berends, Femke; Hottenga, Jouke-Jan; Jensen, Majken K; Johansson, Asa; Junttila, Juhani; Kääb, Stefan; Kanon, Bart; Ketkar, Shamika; Khaw, Kay-Tee; Knowles, Joshua W; Kooner, Angrad S; Kors, Jan A; Kumari, Meena; Milani, Lili; Laiho, Päivi; Lakatta, Edward G; Langenberg, Claudia; Leusink, Maarten; Liu, Yongmei; Luben, Robert N; Lunetta, Kathryn L; Lynch, Stacey N; Markus, Marcello R P; Marques-Vidal, Pedro; Mateo Leach, Irene; McArdle, Wendy L; McCarroll, Steven A; Medland, Sarah E; Miller, Kathryn A; Montgomery, Grant W; Morrison, Alanna C; Müller-Nurasyid, Martina; Navarro, Pau; Nelis, Mari; O'Connell, Jeffrey R; O'Donnell, Christopher J; Ong, Ken K; Newman, Anne B; Peters, Annette; Polasek, Ozren; Pouta, Anneli; Pramstaller, Peter P; Psaty, Bruce M; Rao, Dabeeru C; Ring, Susan M; Rossin, Elizabeth J; Rudan, Diana; Sanna, Serena; Scott, Robert A; Sehmi, Jaban S; Sharp, Stephen; Shin, Jordan T; Singleton, Andrew B; Smith, Albert V; Soranzo, Nicole; Spector, Tim D; Stewart, Chip; Stringham, Heather M; Tarasov, Kirill V; Uitterlinden, André G; Vandenput, Liesbeth; Hwang, Shih-Jen; Whitfield, John B; Wijmenga, Cisca; Wild, Sarah H; Willemsen, Gonneke; Wilson, James F; Witteman, Jacqueline C M; Wong, Andrew; Wong, Quenna; Jamshidi, Yalda; Zitting, Paavo; Boer, Jolanda M A; Boomsma, Dorret I; Borecki, Ingrid B; van Duijn, Cornelia M; Ekelund, Ulf; Forouhi, Nita G; Froguel, Philippe; Hingorani, Aroon; Ingelsson, Erik; Kivimaki, Mika; Kronmal, Richard A; Kuh, Diana; Lind, Lars; Martin, Nicholas G; Oostra, Ben A; Pedersen, Nancy L; Quertermous, Thomas; Rotter, Jerome I; van der Schouw, Yvonne T; Verschuren, W M Monique; Walker, Mark; Albanes, Demetrius; Arnar, David O; Assimes, Themistocles L; Bandinelli, Stefania; Boehnke, Michael; de Boer, Rudolf A; Bouchard, Claude; Caulfield, W L Mark; Chambers, John C; Curhan, Gary; Cusi, Daniele; Eriksson, Johan; Ferrucci, Luigi; van Gilst, Wiek H; Glorioso, Nicola; de Graaf, Jacqueline; Groop, Leif; Gyllensten, Ulf; Hsueh, Wen-Chi; Hu, Frank B; Huikuri, Heikki V; Hunter, David J; Iribarren, Carlos; Isomaa, Bo; Jarvelin, Marjo-Riitta; Jula, Antti; Kähönen, Mika; Kiemeney, Lambertus A; van der Klauw, Melanie M; Kooner, Jaspal S; Kraft, Peter; Iacoviello, Licia; Lehtimäki, Terho; Lokki, Marja-Liisa L; Mitchell, Braxton D; Navis, Gerjan; Nieminen, Markku S; Ohlsson, Claes; Poulter, Neil R; Qi, Lu; Raitakari, Olli T; Rimm, Eric B; Rioux, John D; Rizzi, Federica; Rudan, Igor; Salomaa, Veikko; Sever, Peter S; Shields, Denis C; Shuldiner, Alan R; Sinisalo, Juha; Stanton, Alice V; Stolk, Ronald P; Strachan, David P; Tardif, Jean-Claude; Thorsteinsdottir, Unnur; Tuomilehto, Jaako; van Veldhuisen, Dirk J; Virtamo, Jarmo; Viikari, Jorma; Vollenweider, Peter; Waeber, Gérard; Widen, Elisabeth; Cho, Yoon Shin; Olsen, Jesper V; Visscher, Peter M; Willer, Cristen; Franke, Lude; Erdmann, Jeanette; Thompson, John R; Pfeufer, Arne; Sotoodehnia, Nona; Newton-Cheh, Christopher; Ellinor, Patrick T; Stricker, Bruno H Ch; Metspalu, Andres; Perola, Markus; Beckmann, Jacques S; Smith, George Davey; Stefansson, Kari; Wareham, Nicholas J; Munroe, Patricia B; Sibon, Ody C M; Milan, David J; Snieder, Harold; Samani, Nilesh J; Loos, Ruth J F

    2013-06-01

    Elevated resting heart rate is associated with greater risk of cardiovascular disease and mortality. In a 2-stage meta-analysis of genome-wide association studies in up to 181,171 individuals, we identified 14 new loci associated with heart rate and confirmed associations with all 7 previously established loci. Experimental downregulation of gene expression in Drosophila melanogaster and Danio rerio identified 20 genes at 11 loci that are relevant for heart rate regulation and highlight a role for genes involved in signal transmission, embryonic cardiac development and the pathophysiology of dilated cardiomyopathy, congenital heart failure and/or sudden cardiac death. In addition, genetic susceptibility to increased heart rate is associated with altered cardiac conduction and reduced risk of sick sinus syndrome, and both heart rate-increasing and heart rate-decreasing variants associate with risk of atrial fibrillation. Our findings provide fresh insights into the mechanisms regulating heart rate and identify new therapeutic targets.

  3. Predictors of differences between Type A and B individuals in heart rate and blood pressure reactivity.

    Science.gov (United States)

    Lyness, S A

    1993-09-01

    Past estimates of the magnitude of Type A-B differences in cardiovascular reactivity are probably overly conservative. In addition, it is unclear which situations are more likely to elicit excessive reactivity in Type As. The present meta-analysis found that, overall, Type As had greater heart rate (mean d = .22), diastolic blood pressure (d = .22), and especially systolic blood pressure responses (d = .33) than Type Bs; these effect sizes were small but relatively consistent. However, Type As showed especially greater cardiovascular reactivity in situations characterized as having (a) positive or negative feedback evaluation, (b) socially aversive elements such as verbal harassment or criticism, and (c) elements inherent in playing video games. Measures of time urgency, Type A assessment method, and gender were not found to be strongly related to A-B differences in cardiovascular reactivity. Future studies that use more "Type A-relevant" situations will probably find greater effects.

  4. Evaluation for Intensity of Stress in Lesson using Heart Rate Variability Detected by Simultaneously Measurement

    Science.gov (United States)

    Horiguchi, Ayaka; Takatsu, Hiroaki; Ohno, Wataru; Ozeki, Osamu

    We studied the evaluation for the intensity of stress of students in lesson using heart rate variability. Heart rate of many students were measured simultaneously by developed portable measurement systems. Heart rate variability data suggests that many students have more stress in normal dictation lesson then video lesson using difficult subject.

  5. Discovery of novel heart rate-associated loci using the Exome Chip

    NARCIS (Netherlands)

    van den Berg, Marten E.; Warren, Helen R; Cabrera, Claudia P; Verweij, Niek; Mifsud, Borbala; Haessler, Jeffrey; Bihlmeyer, Nathan A.; Fu, Yi-Ping; Weiss, Stefan; Lin, Henry J.; Grarup, Niels; Li-Gao, Ruifang; Pistis, Giorgio; Shah, Nabi; Brody, Jennifer A.; Mueller-Nurasyid, Martina; Lin, Honghuang; Mei, Hao; Smith, Albert V.; Lyytikainen, Leo-Pekka; Hall, Leanne M; van Setten, Jessica; Trompet, Stella; Prins, Bram P.; Isaacs, Aaron; Radmanesh, Farid; Marten, Jonathan; Entwistle, Aiman; Kors, Jan A.; Silva, Claudia T; Alonso, Alvaro; Bis, Joshua C.; de Boer, Rudolf; de Haan, Hugoline G; de Mutsert, Renee; Dedoussis, George; Dominiczak, Anna F.; Doney, Alex S. F.; Ellinor, Patrick T.; Eppinga, Ruben N.; Felix, Stephan B.; Guo, Xiuqing; Hagemeijer, Yanick; Hansen, Torben; Harris, Tamara B.; Heckbert, Susan R.; Huang, Paul L.; Hwang, Shih-Jen; Kahonen, Mika; Kanters, Jorgen K.; Kolcic, Ivana; Launer, Lenore J.; Li, Man; Yao, Jie; Linneberg, Allan; Liu, Simin; MacFarlane, Peter W.; Mangino, Massimo; Morris, Andrew D.; Mulas, Antonella; Murray, Alison D.; Nelson, Christopher P.; Orru, Marco; Padmanabhan, Sandosh; Peters, Annette; Porteous, David J.; Poulter, Neil; Psaty, Bruce M.; Qi, Lihong; Raitakari, Olli T.; Rivadeneira, Fernando; Roselli, Carolina; Rudan, Igor; Sattar, Naveed; Sever, Peter; Sinner, Moritz F.; Soliman, Elsayed Z.; Spector, Timothy D.; Stanton, Alice V.; Stirrups, Kathleen E; Taylor, Kent D.; Tobin, Martin D.; Uitterlinden, Andre; Vaartjes, Ilonca; Hoes, Arno W.; van der Meer, Peter; Voelker, Uwe; Waldenberger, Melanie; Xie, Zhijun; Zoledziewska, Magdalena; Tinker, Andrew; Polasek, Ozren; Rosand, Jonathan; Jamshidi, Yalda; Duijn, Cornelia Mvan; Zeggini, Eleftheria; Jukema, Wouter J.; Asselbergs, Folkert W.; Samani, Nilesh J.; Lehtimaki, Terho; Gudnason, Vilmundur; Wilson, James G.; Lubitz, Steven A.; Kaeaeb, Stefan; Sotoodehnia, Nona; Caulfield, Mark J.; Palmer, Colin N. A.; Sanna, Serena; Mook-Kanamori, Dennis O.; Deloukas, Panos; Pedersen, Oluf; Rotter, Jerome I.; Doerr, Marcus; O'Donnell, Chris J.; Hayward, Caroline; Arking, Dan E.; Kooperberg, Charles; van der Harst, Pim; Eijgelsheim, Mark; Stricker, Bruno H.; Munroe, Patricia B.

    2017-01-01

    Resting heart rate is a heritable trait, and an increase in heart rate is associated with increased mortality risk. Genome-wide association study analyses have found loci associated with resting heart rate, at the time of our study these loci explained 0.9% of the variation. This study aims to

  6. Discovery of novel heart rate-associated loci using the Exome Chip

    NARCIS (Netherlands)

    M.E. van den Berg (Marten); H. Warren (Helen); Cabrera, C.P. (Claudia P.); Verweij, N. (Niek); Mifsud, B. (Borbala); J. Haessler (Jeff); N.A. Bihlmeyer (Nathan A.); Fu, Y.-P. (Yi-Ping); Weiss, S. (Stefan); Lin, H.J. (Henry J.); N. Grarup (Niels); Li-Gao, R. (Ruifang); G. Pistis (Giorgio); N. Shah (Nisha); J.A. Brody (Jennifer A.); Müller-Nurasyid, M. (Martina); H. Lin (Honghuang); H. Mei (Hao); A.V. Smith (Albert V.); L.-P. Lyytikäinen (Leo-Pekka); L.M. Hall (Leanne M.); J. van Setten (Jessica); S. Trompet (Stella); Prins, B.P. (Bram P.); A.J. Isaacs (Aaron); F. Radmanesh (Farid); J. Marten (Jonathan); Entwistle, A. (Aiman); J.A. Kors (Jan); C.T. Silva (Claudia Tamar); A. Alonso (Alvaro); J.C. Bis (Joshua); R.A. de Boer (Rudolf); H.G. De Haan (Hugoline G.); R. de Mutsert (Reneé); G.V. Dedoussis (George); A. Dominiczak (Anna); A.S.F. Doney (Alex); P.T. Ellinor (Patrick); Eppinga, R.N. (Ruben N.); S.B. Felix (Stephan); X. Guo (Xiuqing); Hagemeijer, Y. (Yanick); T. Hansen (T.); T.B. Harris (Tamara); S.R. Heckbert (Susan); Huang, P.L. (Paul L.); S.-J. Hwang (Shih-Jen); M. Kähönen (Mika); J.K. Kanters; I. Kolcic (Ivana); L.J. Launer (Lenore); M. Li (Man); J. Yao (Jiefen); A. Linneberg (Allan); Liu, S. (Simin); P.W. MacFarlane (Peter); M. Mangino (Massimo); Morris, A.D. (Andrew D.); Mulas, A. (Antonella); Murray, A.D. (Alison D.); C.P. Nelson (Christopher P.); M. Orrù (Marco); S. Padmanabhan (Sandosh); A. Peters (Annette); D.J. Porteous (David J.); N.R. Poulter (Neil); B.M. Psaty (Bruce M.); L. Qi (Lihong); Raitakari, O.T. (Olli T.); Rivadeneira, F. (Fernando); Roselli, C. (Carolina); I. Rudan (Igor); N. Sattar (Naveed); P. Sever (Peter); M.F. Sinner (Moritz); E.Z. Soliman (Elsayed); T.D. Spector (Timothy); A. Stanton (Alice); K. Stirrups (Kathy); K.D. Taylor (Kent); M.D. Tobin (Martin); A.G. Uitterlinden (André); I. Vaartjes (Ilonca); A.W. Hoes (Arno); van der Meer, P. (Peter); U. Völker (Uwe); Waldenberger, M. (Melanie); Xie, Z. (Zhijun); M. Zoledziewska (Magdalena); Tinker, A. (Andrew); O. Polasek (Ozren); J. Rosand (Jonathan); Jamshidi, Y. (Yalda); C.M. van Duijn (Cornelia); E. Zeggini (Eleftheria); J.W. Jukema (Jan Wouter); F.W. Asselbergs (Folkert); N.J. Samani (Nilesh); T. Lehtimäki (Terho); V. Gudnason (Vilmundur); J.F. Wilson (James); Lubitz, S.A. (Steven A.); S. Kääb (Stefan); N. Sotoodehnia (Nona); M. Caulfield (Mark); C.N.A. Palmer (Colin); S. Sanna (Serena); D.O. Mook-Kanamori (Dennis); Deloukas, P. (Panos); O. Pedersen (Oluf); J.I. Rotter (Jerome I.); M. Dörr (Marcus); C.J. O'Donnell (Christopher J.); C. Hayward (Caroline); D.E. Arking (Dan); C. Kooperberg (Charles); van der Harst, P. (Pim); M. Eijgelsheim (Mark); B.H.Ch. Stricker (Bruno); P. Munroe (Patricia)

    2017-01-01

    markdownabstractResting heart rate is a heritable trait, and an increase in heart rate is associated with increased mortality risk. Genome-wide association study analyses have found loci associated with resting heart rate, at the time of our study these loci explained 0.9% of the variation. This

  7. Discovery of novel heart rate-associated loci using the Exome Chip

    DEFF Research Database (Denmark)

    van den Berg, Marten E; Warren, Helen R; Cabrera, Claudia P

    2017-01-01

    Resting heart rate is a heritable trait, and an increase in heart rate is associated with increased mortality risk. Genome-wide association study analyses have found loci associated with resting heart rate, at the time of our study these loci explained 0.9% of the variation. This study aims to di...

  8. Making the Most of the "Daphnia" Heart Rate Lab: Optimizing the Use of Ethanol, Nicotine & Caffeine

    Science.gov (United States)

    Corotto, Frank; Ceballos, Darrel; Lee, Adam; Vinson, Lindsey

    2010-01-01

    Students commonly test the effects of chemical agents on the heart rate of the crustacean "Daphnia" magna, but the procedure has never been optimized. We determined the effects of three concentrations of ethanol, nicotine, and caffeine and of a control solution on heart rate in "Daphnia." Ethanol at 5% and 10% (v/v) reduced mean heart rate to…

  9. Heart Rate and Lactate Levels during Weight-Training Exercise in Trained and Untrained Men.

    Science.gov (United States)

    Stone, Michael H.; And Others

    1987-01-01

    A study of effects of squatting exercise on heart rate and blood lactate levels in trained and untrained males indicated that trained subjects performed more work and had higher heart rates and lactate levels at exhaustion untrained subjects, though heart rate and lactate levels were lower for trained subjects at a given bar mass or submaximal…

  10. Heart Rates of High School Physical Education Students during Team Sports, Individual Sports, and Fitness Activities

    Science.gov (United States)

    Laurson, Kelly R.; Brown, Dale D.; Cullen, Robert W.; Dennis, Karen K.

    2008-01-01

    This study examined how activity type influenced heart rates and time spent in target heart rate zones of high school students participating in physical education classes. Significantly higher average heart rates existed for fitness (142 plus or minus 24 beats per minute [bpm]) compared to team (118 plus or minus 24 bpm) or individual (114 plus or…

  11. Effects of Vibration and G-Loading on Heart Rate, Breathing Rate, and Response Time

    Science.gov (United States)

    Godinez, Angelica; Ayzenberg, Ruthie; Liston, Dorian B.; Stone, Leland S.

    2013-01-01

    Aerospace and applied environments commonly expose pilots and astronauts to G-loading and vibration, alone and in combination, with well-known sensorimotor (Cohen, 1970) and performance consequences (Adelstein et al., 2008). Physiological variables such as heart rate (HR) and breathing rate (BR) have been shown to increase with G-loading (Yajima et al., 1994) and vibration (e.g. Guignard, 1965, 1985) alone. To examine the effects of G-loading and vibration, alone and in combination, we measured heart rate and breathing rate under aerospace-relevant conditions (G-loads of 1 Gx and 3.8 Gx; vibration of 0.5 gx at 8, 12, and 16 Hz).

  12. Using the heart rate variability for classifying patients with and without chronic heart failure and periodic breathing

    OpenAIRE

    Giraldo Giraldo, Beatriz; Téllez, Joan P.; Herrera, Sergio; Benito, Salvador

    2013-01-01

    Assessment of the dynamic interactions between cardiovascular signals can provide valuable information that improves the understanding of cardiovascular control. Heart rate variability (HRV) analysis is known to provide information about the autonomic heart rate modulation mechanism. Using the HRV signal, we aimed to obtain parameters for classifying patients with and without chronic heart failure (CHF), and with periodic breathing (PB), non-periodic breathing (nPB), and Cheyne-Stokes respira...

  13. Analysis of heart rate variability in the presence of ectopic beats using the heart timing signal.

    Science.gov (United States)

    Mateo, Javier; Laguna, Pablo

    2003-03-01

    The time-domain signals representing the heart rate variability (HRV) in the presence of an ectopic beat exhibit a sharp transient at the position of the ectopic beat, which corrupts the signal, particularly the power spectral density (PSD) of the HRV. Consequently, there is a need for correction of this type of beat prior to any HRV analysis. This paper deals with the PSD estimation of the HRV by means of the heart timing (HT) signal when ectopic beats are present. These beat occurrence times are modeled from a generalized, continuous time integral pulse frequency modulation model and, from this point of view, a specific method for minimizing the effect of the presence of ectopic beats is presented to work together with the HT signal. By using both, a white noise driven autoregressive model of the HRV signal with artificially introduced ectopic beats and actual heart rate series including ectopic beats, the more usual methods of HRV spectral estimation are compared. Results of the PSD estimation error function of the number of ectopic beats are presented. These results demonstrate that the proposed method has one order of magnitude lower error than usual ectopic beats removal strategies in preserving PSD, thus, this strategy better recovers the original clinical indexes of interest.

  14. On the structure of atmospheric warming in models and observations: Implications for the lapse rate feedback

    Science.gov (United States)

    Po-Chedley, Stephen D.

    indicate that the prescribed ozone and stratospheric aerosol forcings do not effect T24/TLT amplification in models. On the other hand, model parameterizations for convection and microphysics and, to a lesser degree, uncertainty in the prescribed SST dataset can influence model amplification behavior and bring models into closer accord with observations. In all, significant T24/TLT discrepancies between models and observations remain, but may be reduced with improved model parameterizations. An underlying motivation for understanding the structure of atmospheric warming is that it is responsible for a large negative lapse rate feedback in future climate simulations. To understand factors that control the global lapse rate feedback across models, we use principal component analysis to find the modes of variability that best explain variance in the local lapse rate feedback. We find that models exhibit marked variability in the lapse rate feedback in the southern hemisphere extratropics. This mode is strongly correlated with the global average lapse rate feedback and is largely a function of the competing influence of tropical and Antarctic surface warming. We show that muted southern ocean sea surface warming and the non-local influence of tropical surface warming contributes to a highly variable lapse rate feedback in the sub-Antarctic across models. This behavior is dissimilar to northern hemisphere high latitudes, which are characterized by strong Arctic amplification and a relatively uniform local lapse rate feedback across GCMs. Climatological Antarctic sea ice extent influences Antarctic warming and, as a result, influences both the meridional profile of warming in the southern hemisphere and the global lapse rate feedback.

  15. Resting heart rate and incident heart failure in apparently healthy men and women in the EPIC-Norfolk study.

    Science.gov (United States)

    Pfister, Roman; Michels, Guido; Sharp, Stephen J; Luben, Robert; Wareham, Nick J; Khaw, Kay-Tee

    2012-10-01

    Increasing levels of resting heart rate are associated with increased risk of developing hypertension and cardiovascular disease, and seem to play a role in the progression of heart failure. The shape of the association between resting heart rate and risk of developing heart failure has not been examined in healthy individuals of the general population. Hazard ratios (HRs) of heart failure comparing categories of resting heart rate [51-60 b.p.m. (reference), 61-70 b.p.m., 71-80 b.p.m., 81-90 b.p.m., and 91-100 b.p.m.] were calculated in apparently healthy men (9805) and women (12 321) aged 39-79 participating in the 'European Prospective Investigation into Cancer and Nutrition' (EPIC) study in Norfolk. During a mean follow-up of 12.9 years, 1356 incident cases of heart failure occurred. In participants without potential heart rate-modifying medication, age- and sex-adjusted incidence rates of heart failure were 3.3, 3.7, 4.0, 5.1, and 5.5 per 1000 person-years for increasing categories of resting heart rate; compared with the reference category, HRs and 95% confidence intervals (CI) for increasing categories of resting heart rate were 1.08 (0.88-1.34), 1.17 (0.94-1.46), 1.39 (1.08-1.79), and 1.42 (1.00-2.03), respectively, in multivariable analysis adjusting for age, sex, body mass index, systolic blood pressure, prevalent diabetes, cholesterol concentration, social class, educational level, smoking, and physical activity. Within the reference range of resting heart rate (50-100 b.p.m.) each 10 b.p.m. increase was associated with an 11% increase in hazard of heart failure in multivariable analysis. The results did not change materially after adjusting for myocardial infarction and coronary heart disease events during follow up (1.12, 1.06-1.18). Resting heart rate shows a graded association with hazard of heart failure in apparently healthy men and women which is not mediated by coronary heart disease. Further study is needed to examine the underlying mechanisms.

  16. Impact of sleep-disordered breathing on heart rate turbulence in heart failure patients.

    Science.gov (United States)

    Yoshihisa, Akiomi; Suzuki, Satoshi; Takiguchi, Mai; Shimizu, Takeshi; Abe, Satoshi; Sato, Takamasa; Yamaki, Takayoshi; Sugimoto, Koichi; Kunii, Hiroyuki; Nakazato, Kazuhiko; Suzuki, Hitoshi; Saitoh, Shu-ichi; Takeishi, Yasuchika

    2014-01-01

    Sleep-disordered breathing (SDB) is associated with adverse outcomes in patients with chronic heart failure (CHF). Additionally, heart rate turbulence (HRT) reflects changes in the sinus cycle length of baroreceptor in response to hemodynamic fluctuations after ventricular premature beat. Recent studies have suggested that HRT as a marker of vagal activity has a predictive value of poor prognosis in CHF patients. However, little is known about the relationship between SDB and HRT in CHF patients. In this study, 75 patients with CHF were enrolled. We simultaneously performed Holter ECG during a 24-hr period and portable sleep monitoring at nighttime, and determined the respiratory disturbance index (RDI), HRT (turbulence onset (TO) and turbulence slope (TS)) during that 24-hr period. These patients were divided into two groups based on the presence of severe SDB: Group A (RDI≥30, n = 17) and Group B (RDICHF patients.

  17. On the ergodic secret message capacity of the wiretap channel with finite-rate feedback

    KAUST Repository

    Rezki, Zouheir

    2012-07-01

    We study the secret message capacity of an ergodic block fading wiretap channel with partial channel state information at the transmitter and perfect channel state information at the receivers. We consider that in addition to the statistics of the main and the eavesdropper channel state information (CSI), the sender is provided by the legitimate receiver with a q-bit feedback, at the beginning of each coherence block, through an error-free feedback channel, with capacity q bits. We establish upper and lower bounds on the secrecy capacity. We show that a positive secrecy rate is achievable even when the feedback is at the end of each coherence block and q = 1. We also show that the lower and the upper bounds coincide asymptotically as q → ∞. Finally, asymptotic analysis at high Signal-to-Noise Ratio (SNR) are presented where it is found that the capacity is bounded at high-SNR and present a simple suboptimal scalar quantizer that is capacity achieving, without the need of any numerical optimization, as q → ∞. When applied to Rayleigh fading channels, we show that, at high-SNR, a 4-bit feedback achieves 90% of the secrecy capacity when perfect main CSI is available at the transmitter. © 2012 IEEE.

  18. Mercury Exposure and Heart Rate Variability: a Systematic Review.

    Science.gov (United States)

    Gribble, Matthew O; Cheng, Alan; Berger, Ronald D; Rosman, Lori; Guallar, Eliseo

    2015-09-01

    Mercury affects the nervous system and has been implicated in altering heart rhythm and function. We sought to better define its role in modulating heart rate variability, a well-known marker of cardiac autonomic function. This is a systematic review study. We searched PubMed, Embase, TOXLINE, and DART databases without language restriction. We report findings as a qualitative systematic review because heterogeneity in study design and assessment of exposures and outcomes across studies, as well as other methodological limitations of the literature, precluded a quantitative meta-analysis. We identified 12 studies of mercury exposure and heart rate variability in human populations (ten studies involving primarily environmental methylmercury exposure and two studies involving occupational exposure to inorganic mercury) conducted in Japan, the Faroe Islands, Canada, Korea, French Polynesia, Finland, and Egypt. The association of prenatal mercury exposure with lower high-frequency band scores (thought to reflect parasympathetic activity) in several studies, in particular the inverse association of cord blood mercury levels with the coefficient of variation of the R-R intervals and with low-frequency and high-frequency bands at 14 years of age in the Faroe Islands birth cohort study, suggests that early mercury exposure could have a long-lasting effect on cardiac parasympathetic activity. Studies with later environmental exposures to mercury in children or in adults were heterogeneous and did not show consistent associations. The evidence was too limited to draw firm causal inferences. Additional research is needed to elucidate the effects of mercury on cardiac autonomic function, particularly as early-life exposures might have lasting impacts on cardiac parasympathetic function.

  19. Effect of uterine contractions on fetal heart rate in pregnancy: a prospective observational study.

    Science.gov (United States)

    Sletten, Julie; Kiserud, Torvid; Kessler, Jörg

    2016-10-01

    The new Holter monitoring technology enables long-term electrocardiographic recording of the fetal heart rate without discomfort for the mother. The aim of the study was to assess the feasibility of a fetal Holter monitor. This technology was further used to study fetal heart rate outside the hospital setting during normal daily activities and to test the hypothesis that uterine activity during pregnancy influences fetal heart rate. Prospective observational study including 12 healthy pregnant women at 20-40 weeks of gestation. Data were collected using the Monica AN24 system. Outcome measures were fetal heart rate, maternal heart rate, and uterine activity categorized according to the strength of the electrohysterographic signal. The recordings had a median length of 18.8 h, and fetal heart rate and maternal heart rate were obtained with success rates of 73.1 and 99.9%, respectively. Uterine activity was found to affect fetal heart rate in all participants. Compared with the basal tone and mild levels of uterine activity, moderate and strong levels of uterine activity were associated with increases in fetal heart rate of 4.0 and 5.7 beats/min, respectively. At night, the corresponding increases were 4.9 and 7.6 beats/min. Linear correlations were found between maternal heart rate and fetal heart rate in 11 of the 12 cases, with a mean coefficient beta of 0.189. Both maternal heart rate and fetal heart rate exhibited a diurnal pattern, with lower heart rates being recorded at night. Uterine activity during pregnancy is associated with a graded response in fetal heart rate and may represent a physiological challenge for the development and adaptation of the fetal cardiovascular system. © 2016 Nordic Federation of Societies of Obstetrics and Gynecology.

  20. Heart rate regulation during cycle-ergometer exercise via event-driven biofeedback.

    Science.gov (United States)

    Argha, Ahmadreza; Su, Steven W; Celler, Branko G

    2017-03-01

    This paper is devoted to the problem of regulating the heart rate response along a predetermined reference profile, for cycle-ergometer exercises designed for training or cardio-respiratory rehabilitation. The controller designed in this study is a non-conventional, non-model-based, proportional, integral and derivative (PID) controller. The PID controller commands can be transmitted as biofeedback auditory commands, which can be heard and interpreted by the exercising subject to increase or reduce exercise intensity. However, in such a case, for the purposes of effectively communicating to the exercising subject a change in the required exercise intensity, the timing of this feedback signal relative to the position of the pedals becomes critical. A feedback signal delivered when the pedals are not in a suitable position to efficiently exert force may be ineffective and this may, in turn, lead to the cognitive disengagement of the user from the feedback controller. This note examines a novel form of control system which has been expressly designed for this project. The system is called an "actuator-based event-driven control system". The proposed control system was experimentally verified using 24 healthy male subjects who were randomly divided into two separate groups, along with cross-validation scheme. A statistical analysis was employed to test the generalisation of the PID tunes, derived based on the average transfer functions of the two groups, and it revealed that there were no significant differences between the mean values of root mean square of the tracking error of two groups (3.9 vs. 3.7 bpm, [Formula: see text]). Furthermore, the results of a second statistical hypothesis test showed that the proposed PID controller with novel synchronised biofeedback mechanism has better performance compared to a conventional PID controller with a fixed-rate biofeedback mechanism (Group 1: 3.9 vs. 5.0 bpm, Group 2: 3.7 vs. 4.4 bpm, [Formula: see text]).

  1. Facets of psychopathy, heart rate variability and cognitive function.

    Science.gov (United States)

    Hansen, Anita Lill; Johnsen, Bjørn Helge; Thornton, David; Waage, Leif; Thayer, Julian F

    2007-10-01

    The aim of the present study was to investigate whether the four facets of Hare's Psychopathy Checklist-Revised (PCL-R; Hare, 1991; Bolt, Hare, Vitale, & Newman, 2004) were related to physiological and cognitive mechanisms. Fifty-three male prisoners participated in this study. Physiological responses were measured as heart rate variability (HRV) and heart rate (HR). Cognitive functions were measured using a continuous performance test (CPT; California Computerized Assessment Package, Abbreviated version) and a working memory test (WMT); based on Baddeley & Hitch (1974). The regression analysis of the HRV revealed that the interpersonal facet explained most of the variance during baseline (28%), CPT (16%), and WMT (12%). This was also true for the HR data during baseline (28%), CPT (20%), WMT (10%), and recovery (13%). The antisocial facet explained 10% of the variance only during baseline. Subjects scoring high compared to low on the interpersonal facet also showed better cognitive functioning. The study suggests that the different facets were differently associated with both physiological and cognitive functions.

  2. Human heart rate variability relation is unchanged during motion sickness

    Science.gov (United States)

    Mullen, T. J.; Berger, R. D.; Oman, C. M.; Cohen, R. J.

    1998-01-01

    In a study of 18 human subjects, we applied a new technique, estimation of the transfer function between instantaneous lung volume (ILV) and instantaneous heart rate (HR), to assess autonomic activity during motion sickness. Two control recordings of ILV and electrocardiogram (ECG) were made prior to the development of motion sickness. During the first, subjects were seated motionless, and during the second they were seated rotating sinusoidally about an earth vertical axis. Subjects then wore prism goggles that reverse the left-right visual field and performed manual tasks until they developed moderate motion sickness. Finally, ILV and ECG were recorded while subjects maintained a relatively constant level of sickness by intermittent eye closure during rotation with the goggles. Based on analyses of ILV to HR transfer functions from the three conditions, we were unable to demonstrate a change in autonomic control of heart rate due to rotation alone or due to motion sickness. These findings do not support the notion that moderate motion sickness is manifested as a generalized autonomic response.

  3. Heart rate variability (HRV) during virtual reality immersion.

    Science.gov (United States)

    Malińska, Marzena; Zużewicz, Krystyna; Bugajska, Joanna; Grabowski, Andrzej

    2015-01-01

    The goal of the study was assessment of the hour-long training involving handling virtual environment (sVR) and watching a stereoscopic 3D movie on the mechanisms of autonomic heart rate (HR) regulation among the subjects who were not predisposed to motion sickness. In order to exclude predispositions to motion sickness, all the participants (n=19) underwent a Coriolis test. During an exposure to 3D and sVR the ECG signal was continuously recorded using the Holter method. For the twelve consecutive 5-min epochs of ECG signal, the analysis of heart rate variability (HRV) in time and frequency domains was conducted. After 30 min from the beginning of the training in handling the virtual workstation a significant increase in LF spectral power was noted. The values of the sympathovagal LF/HF index while sVR indicated a significant increase in sympathetic predominance in four time intervals, namely between the 5th and the 10th minute, between the 15th and the 20th minute, between the 35th and 40th minute and between the 55th and the 60th minute of exposure.

  4. Noisy fluctuation of heart rate indicates cardiovascular system instability.

    Science.gov (United States)

    Fortrat, Jacques-Olivier; Baum, Charlotte; Jeanguillaume, Christian; Custaud, Marc-Antoine

    2013-09-01

    Heart rate spontaneously fluctuates despite homeostatic regulatory mechanisms to stabilize it. Harmonic and fractal fluctuations have been described. Non-harmonic non-fractal fluctuation has not been studied because it is usually thought that it is caused by apparatus noise. We hypothesized that this fluctuation looking like apparatus noise (that we call "noisy fluctuation") is linked to challenged blood pressure stabilization and not to apparatus noise. We assessed noisy fluctuation by quantifying the small and fastest beat-to-beat fluctuation of RR-interval by means of spectral analysis (Nyquist power of heart rate variability: nyHRV) after filtering out its fractal component. We observed nyHRV in healthy supine subjects and in patients with vasovagal symptoms. We challenged stabilization of blood pressure by upright posture (by means of a head-up tilt table test). Head-up position on the tilt table dramatically decreased nyHRV (0.128 ± 0.063 vs. 0.004 ± 0.002, p cardiovascular system is challenged (upright posture). It also indicates cardiovascular instability because it does not disappear in upright patients before vasovagal syncope, a transient failure of cardiovascular regulation.

  5. Importance of heart rate analysis in exercise tolerance test

    Directory of Open Access Journals (Sweden)

    Artur Haddad Herdy

    2003-08-01

    Full Text Available After many years away from the limelights, at the beginning of this century, exercise tolerance testing has earned back an important position in international medical journals. The different sorts of information derived from a variety of studies based on it have shown us that this propedeutic method has a highly valuable prognostic impact. Because of its low cost and easy applicability, the exercise testing reinforces its position in the clinical practice of the cardiologist. In the early 70's, research relating the influence of the autonomic nervous system in heart rate behavior in all phases of an exercise tolerance testing began. Ever since, a number of hypotheses tried to clarify which would be the mechanisms related to the chronotropic response during effort and its performance in the recovery period. In this updating article the authors deal with an important data referring to the chronotropic deficit and the abnormal heart rate recovery, commenting on the prognostic implication of keeping the focus on the potential of its clinical impact. In other words, approaches that can be used whenever there is someone performing a monitored exercise tolerance testing.

  6. Heart rate and sentiment experimental data with common timeline.

    Science.gov (United States)

    Salamon, Jaromír; Mouček, Roman

    2017-12-01

    Sentiment extraction and analysis using spoken utterances or written corpora as well as collection and analysis of human heart rate data using sensors are commonly used techniques and methods. On the other hand, these have been not combined yet. The collected data can be used e.g. to investigate the mutual dependence of human physical and emotional activity. The paper describes the procedure of parallel acquisition of heart rate sensor data and tweets expressing sentiment and difficulties related to this procedure. The obtained datasets are described in detail and further discussed to provide as much information as possible for subsequent analyses and conclusions. Analyses and conclusions are not included in this paper. The presented experiment and provided datasets serve as the first basis for further studies where all four presented data sources can be used independently, combined in a reasonable way or used all together. For instance, when the data is used all together, performing studies comparing human sensor data, acquired noninvasively from the surface of the human body and considered as more objective, and human written data expressing the sentiment, which is at least partly cognitively interpreted and thus considered as more subjective, could be beneficial.

  7. Correlation between electroencephalography and heart rate variability during sleep.

    Science.gov (United States)

    Ako, Mina; Kawara, Tokuhiro; Uchida, Sunao; Miyazaki, Shinichi; Nishihara, Kyoko; Mukai, Junko; Hirao, Kenzo; Ako, Junya; Okubo, Yoshiro

    2003-02-01

    It is known that autonomic nervous activities change in correspondence with sleep stages. However, the characteristics of continuous fluctuations in nocturnal autonomic nerve tone have not been clarified in detail. The study aimed to determine the possible correlation between the electroencephalogram (EEG) and autonomic nervous activities, and to clarify in detail the nocturnal fluctuations in autonomic nerve activities. Overnight EEGs and electrocardiograms of seven healthy males were obtained. These EEGs were analyzed by fast Fourier transformation algorithm to extract delta, sigma and beta power. Heart rate and heart rate variability (HRV) were calculated in consecutive 5-min epochs. The HRV indices of low frequency (LF), high frequency (HF) and LF/HF ratio were calculated from the spectral analysis of R-R intervals. The sleep stages were manually scored according to Rechtschaffen and Kales' criteria. Low frequency and LF/HF were significantly lower during non-rapid eye movement (NREM) than REM, and were lower in stages 3 and 4 than in stages 1 and 2. Furthermore, delta EEG showed inverse correlations with LF (r = - 0.44, P lightening.

  8. Smartphone-based photoplethysmographic imaging for heart rate monitoring.

    Science.gov (United States)

    Alafeef, Maha

    2017-07-01

    The purpose of this study is to make use of visible light reflected mode photoplethysmographic (PPG) imaging for heart rate (HR) monitoring via smartphones. The system uses the built-in camera feature in mobile phones to capture video from the subject's index fingertip. The video is processed, and then the PPG signal resulting from the video stream processing is used to calculate the subject's heart rate. Records from 19 subjects were used to evaluate the system's performance. The HR values obtained by the proposed method were compared with the actual HR. The obtained results show an accuracy of 99.7% and a maximum absolute error of 0.4 beats/min where most of the absolute errors lay in the range of 0.04-0.3 beats/min. Given the encouraging results, this type of HR measurement can be adopted with great benefit, especially in the conditions of personal use or home-based care. The proposed method represents an efficient portable solution for HR accurate detection and recording.

  9. Healthy lifestyle and heart rate variability in young adults.

    Science.gov (United States)

    Aeschbacher, Stefanie; Bossard, Matthias; Ruperti Repilado, Francisco Javier; Good, Nathalie; Schoen, Tobias; Zimny, Matylda; Probst-Hensch, Nicole M; Schmidt-Trucksäss, Arno; Risch, Martin; Risch, Lorenz; Conen, David

    2016-07-01

    We aimed to determine the association of a comprehensive healthy lifestyle with heart rate variability (HRV), a validated measure of autonomic function. This was a prospective cohort study. A population-based sample of 2079 individuals aged 25-41 years without prevalent cardiovascular disease was investigated. The standard deviation of all normal RR intervals (SDNN) during 24-hour electrocardiography was used as main HRV marker. Healthy lifestyle metrics were summed to a validated lifestyle-score ranging from 0 = most unhealthy to 7 = most healthy. One point was given for each of the following items: never smoking cigarettes; consuming a healthy diet; performing moderate (≥150 min/week) or vigorous (≥75 min/week) physical activity; body mass index (BMI)heart rate (HR) (β-estimate (95% CI) 0.07 (0.07-0.10), p healthy lifestyle in this large contemporary cohort of young adults from the general population. Adopting a healthy lifestyle has an important effect on autonomic function. © The European Society of Cardiology 2015.

  10. The relationship of heart rate and lactate to cumulative muscle fatigue during recreational alpine skiing.

    Science.gov (United States)

    Seifert, John; Kröll, Josef; Müller, Erich

    2009-05-01

    Common indices of fatigue may not respond similarly between downhill skiing and other activities because of the influence of factors such as snow conditions, changing terrain, and skiing style. The purpose of this study was to investigate the relationship and predictors of common fatigue indices during downhill skiing. Ten healthy female recreational skiers skied for 3 hours under standardized conditions. Feedback on heart rate (HR) and finishing time were given to each skier at the end of each run to maintain a relatively stable load. A chronic stress score (Cstress) was calculated from creatine kinase (CK), cortisol, and isometric endurance. Finishing times and HR from runs 2, 12, and 24 were similar. Heart rate averaged 82% of HRmax. Heart rate was an insignificant predictor (p = .65) and was poorly correlated (r = 0.16) to Cstress. Blood lactate (LA) was a significant predictor of the Cstress (p = 0.05; r = 0.62). Pre- to postskiing peak forces were not different (p = 0.62), but skiers experienced a significant decrease in isometric endurance from 106.1 +/- 29.6 to 93.2 +/- 24.0 seconds. Endurance decreased by 13%, whereas cortisol and CK increased by 16 and 42%, respectively. Isometric contraction endurance and blood LA were significant predictors of overall stress. Individual compensation mechanisms and skiing style contributed to highly variable responses during skiing. Whereas HR may indicate stress within a given run, it is not a significant indicator of Cstress and fatigue during recreational alpine skiing. However, the cumulative stress variables and LA can be used in field testing of skiers. It is suggested that LA is a practical on-hill marker of chronic stress.

  11. Assessment of cardiac autonomic functions by heart rate recovery, heart rate variability and QT dynamicity parameters in patients with acromegaly.

    Science.gov (United States)

    Dural, Muhammet; Kabakcı, Giray; Cınar, Neşe; Erbaş, Tomris; Canpolat, Uğur; Gürses, Kadri Murat; Tokgözoğlu, Lale; Oto, Ali; Kaya, Ergün Barış; Yorgun, Hikmet; Sahiner, Levent; Dağdelen, Selçuk; Aytemir, Kudret

    2014-04-01

    Cardiovascular complications are the most common causes of morbidity and mortality in acromegaly. However, there is little data regarding cardiac autonomic functions in these patients. Herein, we aimed to investigate several parameters of cardiac autonomic functions in patients with acromegaly compared to healthy subjects. We enrolled 20 newly diagnosed acromegalic patients (55% female, age:45.7 ± 12.6 years) and 32 age- and gender-matched healthy subjects. All participants underwent 24 h Holter recording. Heart rate recovery (HRR) indices were calculated by subtracting 1st, 2nd and 3rd minute heart rates from maximal heart rate. All patients underwent heart rate variability (HRV) and QT dynamicity analysis. Baseline characteristics were similar except diabetes mellitus and hypertension among groups. Mean HRR1 (29.2 ± 12.3 vs 42.6 ± 6.5, p = 0.001), HRR2 (43.5 ± 15.6 vs 61.1 ± 10.8, p = 0.001) and HRR3 (46.4 ± 16.2 vs 65.8 ± 9.8, p = 0.001) values were significantly higher in control group. HRV parameters as, SDNN [standard deviation of all NN intervals] (p = 0.001), SDANN [SD of the 5 min mean RR intervals] (p = 0.001), RMSSD [root square of successive differences in RR interval] (p = 0.001), PNN50 [proportion of differences in successive NN intervals >50 ms] (p = 0.001) and high-frequency [HF] (p = 0.001) were significantly decreased in patients with acromegaly; but low frequency [LF] (p = 0.046) and LF/HF (p = 0.001) were significantly higher in acromegaly patients. QTec (p = 0.009), QTac/RR slope (p = 0.017) and QTec/RR slope (p = 0.01) were significantly higher in patients with acromegaly. Additionally, there were significant negative correlation of disease duration with HRR2, HRR3, SDNN, PNN50, RMSSD, variability index. Our study results suggest that cardiac autonomic functions are impaired in patients with acromegaly. Further large scale studies are needed to exhibit the prognostic significance of impaired autonomic functions in patients with

  12. Modeling baroreflex regulation of heart rate during orthostatic stress

    DEFF Research Database (Denmark)

    Olufsen, Mette; Tran, Hien T.; Ottesen, Johnny T.

    2006-01-01

    in healthy and hypertensive elderly people the hysteresis loop shifts to higher blood pressure values and its area is diminished. Finally, for hypertensive elderly people the hysteresis loop is generally not closed indicating that during postural change from sitting to standing, the blood pressure resettles....... The model uses blood pressure measured in the finger as an input to model heart rate dynamics in response to changes in baroreceptor nerve firing rate, sympathetic and parasympathetic responses, vestibulo-sympathetic reflex, and concentrations of norepinephrine and acetylcholine. We formulate an inverse...... validate our model against clinical data it is necessary to include the vestibulo-sympathetic reflex. Furthermore our model reveals that the transfer between the nerve firing and blood pressure is non-linear and follows a hysteresis curve. In healthy young people, the hysteresis loop is wide, while...

  13. Fetal heart rate pattern recognition by the method of auscultation.

    Science.gov (United States)

    Miller, F C; Pearse, K E; Paul, R H

    1984-09-01

    The thesis that obstetric health care personnel can discriminate characteristics of baseline fetal heart rate (FHR) and FHR patterns by auscultation needs to be tested. For this study, audiotones of the FHR signals were recorded for eight representative FHR patterns. Each recording was for three minutes and included one uterine contraction. Physicians and nurses who use continuous electronic FHR monitoring on a regular basis listened to the eight recordings and attempted to identify the baseline rate, variability, and periodic patterns, and then matched their perceptions with the eight corresponding FHR tracings (not in order). Baseline FHR and FHR without periodic patterns were most frequently identified correctly. Late decelerations with and without good baseline variability were misdiagnosed 18.4 and 33% of the time, respectively. Although the FHR characteristics and periodic patterns were correctly identified most of the time, failure to recognize significant periodic patterns by as many as one-third of the participants is unacceptable in modern obstetrics.

  14. Resting heart rate as predictor for left ventricular dysfunction and heart failure: MESA (Multi-Ethnic Study of Atherosclerosis).

    Science.gov (United States)

    Opdahl, Anders; Ambale Venkatesh, Bharath; Fernandes, Veronica R S; Wu, Colin O; Nasir, Khurram; Choi, Eui-Young; Almeida, Andre L C; Rosen, Boaz; Carvalho, Benilton; Edvardsen, Thor; Bluemke, David A; Lima, João A C

    2014-04-01

    The objective of this study was to investigate the relationship between baseline resting heart rate and incidence of heart failure (HF) and global and regional left ventricular (LV) dysfunction. The association of resting heart rate to HF and LV function has not been well described in an asymptomatic multi-ethnic population. Resting heart rate was measured in participants in the MESA (Multi-Ethnic Study of Atherosclerosis) trial at inclusion. Incident HF was registered (n = 176) during follow-up (median 7 years) in those who underwent cardiac magnetic resonance imaging (n = 5,000). Changes in ejection fraction (ΔEF) and peak circumferential strain (Δεcc) were measured as markers of developing global and regional LV dysfunction in 1,056 participants imaged at baseline and 5 years later. Time to HF (Cox model) and Δεcc and ΔEF (multiple linear regression models) were adjusted for demographics, traditional cardiovascular risk factors, calcium score, LV end-diastolic volume, and mass in addition to resting heart rate. Cox analysis demonstrated that for 1 beat/min increase in resting heart rate, there was a 4% greater adjusted relative risk for incident HF (hazard ratio: 1.04; 95% CI: 1.02 to 1.06; p heart rate was positively associated with deteriorating εcc and decrease in EF, even when all coronary heart disease events were excluded from the model. Elevated resting heart rate was associated with increased risk for incident HF in asymptomatic participants in the MESA trial. Higher heart rate was related to development of regional and global LV dysfunction independent of subclinical atherosclerosis and coronary heart disease. (Multi-Ethnic Study of Atherosclerosis [MESA]; NCT00005487). Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  15. Hyperglycemia and hyperlipidemia blunts the Insulin-Inpp5f negative feedback loop in the diabetic heart.

    Science.gov (United States)

    Bai, Danna; Zhang, Yajun; Shen, Mingzhi; Sun, Yongfeng; Xia, Qing; Zhang, Yingmei; Liu, Xuedong; Wang, Haichang; Yuan, Lijun

    2016-02-24

    The leading cause of death in diabetic patients is diabetic cardiomyopathy, in which alteration of Akt signal plays an important role. Inpp5f is recently found to be a negative regulator of Akt signaling, while its expression and function in diabetic heart is largely unknown. In this study, we found that in both the streptozotocin (STZ) and high fat diet (HFD) induced diabetic mouse models, Inpp5f expression was coordinately regulated by insulin, blood glucose and lipid levels. Increased Inpp5f was inversely correlated with the cardiac function. Further studies revealed that Insulin transcriptionally activated Inpp5f in an Sp1 dependent manner, and increased Inpp5f in turn reduced the phosphorylation of Akt, forming a negative feedback loop. The negative feedback plays a protective role under diabetic condition. However, high blood glucose and lipid, which are characteristics of uncontrolled diabetes and type 2 diabetes, increased Inpp5f expression through activation of NF-κB, blunts the protective feedback. Thus, our study has revealed that Inpp5f provides as a negative feedback regulator of insulin signaling and downregulation of Inpp5f in diabetes is cardioprotective. Increased Inpp5f by hyperglycemia and hyperlipidemia is an important mediator of diabetic cardiomyopathy and is a promising therapeutic target for the disease.

  16. Sternal Pulse Rate Variability Compared with Heart Rate Variability on Healthy Subjects

    DEFF Research Database (Denmark)

    Chreiteh, Shadi; Belhage, Bo; Hoppe, Karsten

    2014-01-01

    The heart rate variability (HRV) is a commonly used method to quantify the sympathetic and the parasympathetic modulation of the heart rate. HRV is mainly conducted on electrocardiograms (ECG). However, the use of photoplethysmography (PPG) as a marker of the autonomic tone is emerging....... In this study we investigated the feasibility of deriving pulse rate variability (PRV) using PPG signals recorded by a reflectance PPG sensor attached to the chest bone (sternum) and comparing it to HRV. The recordings were conducted on 9 healthy subjects being in a relaxed supine position and under forced...... the parameters (r > 0:95 with p using sternal PPG can be an alternative to HRV analysis on healthy subjects at rest....

  17. Estimating 'lost heart beats' rather than reductions in heart rate during the intubation of critically-ill children.

    Science.gov (United States)

    Jones, Peter; Ovenden, Nick; Dauger, Stéphane; Peters, Mark J

    2014-01-01

    Reductions in heart rate occur frequently in children during critical care intubation and are currently considered the gold standard for haemodynamic instability. Our objective was to estimate loss of heart beats during intubation and compare this to reduction in heart rate alone whilst testing the impact of atropine pre-medication. Data were extracted from a prospective 2-year cohort study of intubation ECGs from critically ill children in PICU/Paediatric Transport. A three step algorithm was established to exclude variation in pre-intubation heart rate (using a 95%CI limit derived from pre-intubation heart rate variation of the children included), measure the heart rate over time and finally the estimate the numbers of lost beats. 333 intubations in children were eligible for inclusion of which 245 were available for analysis (74%). Intubations where the fall in heart rate was less than 50 bpm were accompanied almost exclusively by less than 25 lost beats (n = 175, median 0 [0-1]). When there was a reduction of >50 bpm there was a poor correlation with numbers of lost beats (n = 70, median 42 [15-83]). During intubation the median number of lost beats was 8 [1]-[32] when atropine was not used compared to 0 [0-0] when atropine was used (pheart rate during intubation of heart rate was >50 bpm the heart rate was poorly predictive of lost beats. A study looking at the relationship between lost beats and cardiac output needs to be performed. Atropine reduces both fall in heart rate and loss of beats. Similar area-under-the-curve methodology may be useful for estimating risk when biological parameters deviate outside normal range.

  18. A method to detect heart rate based on electrical bio-impedance

    Directory of Open Access Journals (Sweden)

    Li Kun-Yang

    2016-01-01

    Full Text Available As a basic health indicator, heart rate has been widely used in clinical measurement and daily health care. Electrical bio-impedance (EBI measurement provides non-invasive method for heart rate detection. Therefore, this paper proposed a method to detect heart rate based on EBI. With the BIOPAC EBI module, the signal can be de-noised in real-time. Finally, the de-noised EBI signal is used to compute heart rate. Four electrodes are located at radial artery of left upper limb in this method. The result proves that this method has high accuracy on heart rate measurement.

  19. Non-Bayesian Rate-Adaptive Wireless Communication Using ARQ-Feedback

    CERN Document Server

    Koksal, C Emre

    2009-01-01

    To combat the detrimental effects of the variability in wireless channels, we consider cross-layer rate adaptation. We study communication systems that utilize the limited feedback in the form of link-layer Automatic Repeat-reQuest (ARQ) to maximize the physical-layer transmission rate, subject to a certain upper bound on the expected packet error rate. We assume that there is no knowledge of the prior distribution of the channel state at the transmitter. We first analyze the fundamental limitations of such systems and derive an upper bound on the achievable rate for signalling schemes based on uncoded modulation with QAM and random-coded modulation with Gaussian ensembles. We show that, for channel estimation based on binary ARQ feedback, it may be preferable to use a separate training sequence at high error rates, rather than to exploit low-error-rate data packets themselves. We also develop an adaptive recursive estimator, which is provably asymptotically optimal and asymptotically efficient.

  20. Prognostic significance of heart rate turbulence parameters in patients with chronic heart failure.

    Science.gov (United States)

    Yin, De-Chun; Wang, Zhao-Jun; Guo, Shuai; Xie, Hong-Yu; Sun, Lin; Feng, Wei; Qiu, Wei; Qu, Xiu-Fen

    2014-04-13

    This study is aimed to evaluate the clinical significance of heart rate turbulence (HRT) parameters in predicting the prognosis in patients with chronic heart failure (CHF). From June 2011 to December 2012, a total of 104 CHF patients and 30 healthy controls were enrolled in this study. We obtained a 24-hour Holter ECG recording to assess the HRT parameters, included turbulence onset (TO), turbulence slope (TS), standard deviation of N-N intervals (SDNN), and resting heart rate (RHR). The relationships between HRT parameters and the prognosis of CHF patients were determined. The assessment follow-up period lasted until January 31, 2013. The overall mortality of CHF patients was 9.6% (10/104). Our results revealed that CHF patients had higher levels of TO than those of healthy subjects, but the TS levels of CHF patients were lower than that of the control group. CHF patients with NYHA grade IV had higher HRT1/2 rate than those with NYHA grade II/III. There were statistical differences in TS, LVEF, SDNN and RHR between the non-deteriorating group and the non-survivor group. Significant differences in TS among the three groups were also found. Furthermore, CHF patients in the non-survivor group had lower levels of TS than those in the deteriorating group. Correlation analyses indicated that TO negatively correlate with SDNN, while TS positively correlated with SDNN and left ventricular ejection fraction (LVEF). We also observed negative correlations between TS and left ventricular end-diastolic cavity dimension (LVEDD), RHR, homocysteine (Hcy) and C-reactive protein (CRP). Multivariate Cox regression analysis further confirmed that LVEF (≤30%), HRT2, SDNN and RHR were independent risk factors which can indicate poor prognosis in CHF patients. Our findings indicate that HRT may have good clinical predictive value in patients with CHF. Thus, quantifying HRT parameters could be a useful tool for predicting mortality in CHF patients.

  1. Clinical significance of heart rate turbulence assessment in patients with chronic heart failure.

    Science.gov (United States)

    Szymanowska, Katarzyna; Piatkowska, Anna; Nowicka, Anna; Michalski, Marek; Dankowski, Rafał; Kandziora, Magdalena; Biegalski, Wojciech; Wierzchowiecki, Michał; Poprawski, Kajetan

    2008-12-01

    Heart rate turbulence (HRT) is modulated by the baroreceptor reflex, and it has been suggested that it could be used as a measure of autonomic dysfunction. Impaired HRT has a significant prognostic value in patients after myocardial infarction. The usefulness of HRT parameters in CHF patients has not yet been well established. To assess the relationship between HRT parameters, clinical course of CHF and selected biochemical markers with respect to their prognostic value in CHF patients. A 64 of 100 consecutive CHF patients, in whom it was possible to calculate HRT, were divided into four groups according to NYHA class. Uric acid (UA) and brain natriuretic peptide (BNP) concentrations were measured. Heart rate turbulence was analysed from 24-hour Holter ECG and characterised by two parameters: turbulence onset (TO) and turbulence slope (TS). The results of 20 healthy persons served as a control group. Follow-up examinations were performed after 6 and 12 months. In patients with CHF both HRT parameters (TO and TS) were significantly impaired in comparison to TO and TS in healthy subjects. A negative correlation between these parameters was found. A strong positive correlation between TO and NYHA class and a significant negative correlation between TS and BNP and UA concentrations were observed. There were 11 deaths during one-year follow-up. Patients who died due to CHF had significantly lower TS and higher TO values in comparison to survivors. Heart rate turbulence is impaired in CHF patients. HRT parameters show a significant correlation with some clinical factors: NYHA class, BNP and UA concentrations. Both HRT parameters, TO and TS, seem to be significant prognostic markers in patients with CHF.

  2. An Overview of Heart Rate Variability Metrics and Norms

    Directory of Open Access Journals (Sweden)

    Fred Shaffer

    2017-09-01

    Full Text Available Healthy biological systems exhibit complex patterns of variability that can be described by mathematical chaos. Heart rate variability (HRV consists of changes in the time intervals between consecutive heartbeats called interbeat intervals (IBIs. A healthy heart is not a metronome. The oscillations of a healthy heart are complex and constantly changing, which allow the cardiovascular system to rapidly adjust to sudden physical and psychological challenges to homeostasis. This article briefly reviews current perspectives on the mechanisms that generate 24 h, short-term (~5 min, and ultra-short-term (<5 min HRV, the importance of HRV, and its implications for health and performance. The authors provide an overview of widely-used HRV time-domain, frequency-domain, and non-linear metrics. Time-domain indices quantify the amount of HRV observed during monitoring periods that may range from ~2 min to 24 h. Frequency-domain values calculate the absolute or relative amount of signal energy within component bands. Non-linear measurements quantify the unpredictability and complexity of a series of IBIs. The authors survey published normative values for clinical, healthy, and optimal performance populations. They stress the importance of measurement context, including recording period length, subject age, and sex, on baseline HRV values. They caution that 24 h, short-term, and ultra-short-term normative values are not interchangeable. They encourage professionals to supplement published norms with findings from their own specialized populations. Finally, the authors provide an overview of HRV assessment strategies for clinical and optimal performance interventions.

  3. Separating the effect of respiration from the heart rate variability for cases of constant harmonic breathing

    Directory of Open Access Journals (Sweden)

    Kircher Michael

    2015-09-01

    Full Text Available Heart Rate Variability studies are a known measure for the autonomous control of the heart rate. In special situations, its interpretation can be ambiguous, since the respiration has a major influence on the heart rate variability. For this reason it has often been proposed to measure Heart Rate Variability, while the subjects are breathing at a constant respiration rate. That way the spectral influence of the respiration is known. In this work we propose to remove this constant respiratory influence from the heart rate and the Heart Rate Variability parameters to gain respiration free autonomous controlled heart rate signal. The spectral respiratory component in the heart rate signal is detected and characterized. Subsequently the respiratory effect on Heart Rate Variability is removed using spectral filtering approaches, such as the Notch filter or the Raised Cosine filter. As a result new decoupled Heart Variability parameters are gained, which could lead to new additional interpretations of the autonomous control of the heart rate.

  4. Simultaneous measurement of instantaneous heart rate and chest wall plethysmography in short-term, metronome guided heart rate variability studies: suitability for assessment of autonomic dysfunction.

    Science.gov (United States)

    Perring, S; Jones, E

    2003-08-01

    Instantaneous heart rate and chest wall motion were measured using a 3-lead ECG and an air pressure chest wall plethysmography system. Chest wall plethysmography traces were found to accurately represent the breathing pattern as measured by spirometry (average correlation coefficient 0.944); though no attempt was made to calibrate plethysmography voltage output to tidal volume. Simultaneous measurements of heart rate and chest wall motion were made for short periods under metronome guided breathing at 6 breaths per minute. The average peak to trough heart rate change per breath cycle (AVEMAX) and maximum correlation between heart rate and breathing cycle (HRBRCORR) were measured. Studies of 44 normal volunteers indicated clear inverse correlation of heart rate variability parameters with age (AVEMAX R = -0.502, P heart rate variability in diabetics (P = 0.005 for AVEMAX) and significantly worse correlation between heart rate and breathing (P measurement of heart rate and breathing offers the possibility of more sensitive diagnosis of autonomic failure in a simple bedside test and gives further insight into the nature of cardio-ventilatory coupling.

  5. Relative influence of age, resting heart rate and sedentary life style in short-term analysis of heart rate variability

    Directory of Open Access Journals (Sweden)

    E.R. Migliaro

    2001-04-01

    Full Text Available In order to assess the relative influence of age, resting heart rate (HR and sedentary life style, heart rate variability (HRV was studied in two different groups. The young group (YG consisted of 9 sedentary subjects aged 15 to 20 years (YG-S and of 9 nonsedentary volunteers (YG-NS also aged 15 to 20. The elderly sedentary group (ESG consisted of 16 sedentary subjects aged 39 to 82 years. HRV was assessed using a short-term procedure (5 min. R-R variability was calculated in the time-domain by means of the root mean square successive differences. Frequency-domain HRV was evaluated by power spectrum analysis considering high frequency and low frequency bands. In the YG the effort tolerance was ranked in a bicycle stress test. HR was similar for both groups while ESG showed a reduced HRV compared with YG. Within each group, HRV displayed a negative correlation with HR. Although YG-NS had better effort tolerance than YG-S, their HR and HRV were not significantly different. We conclude that HRV is reduced with increasing HR or age, regardless of life style. The results obtained in our short-term study agree with others of longer duration by showing that age and HR are the main determinants of HRV. Our results do not support the idea that changes in HRV are related to regular physical activity.

  6. CAFFEINE IMPROVES HEART RATE WITHOUT IMPROVING SEPSIS SURVIVAL

    Science.gov (United States)

    Bauzá, Gustavo; Remick, Daniel

    2015-01-01

    Introduction Caffeine is consumed on a daily basis for its nervous system stimulant properties and is a global adenosine receptor antagonist. Since adenosine receptors have been found to play a major role in regulating the immune response to a septic insult, we investigated if caffeine consumption prior to a septic insult would alter immunological and physiological responses, as well as survival. Methods Two separate experimental designs were employed, both using outbred female ICR mice. In the first experiment mice were administered 20mg/kg of caffeine (equal to 2–3 cups of coffee for a human) or normal saline intraperitoneally at the time of cecal ligation and puncture (CLP). Immunological parameters including cytokines and local cell recruitment measured. In the second experiment caffeine (10mg/kg/hr) was delivered continuously for 24 hours via a subcutaneous infusion pump placed the day prior to CLP and hemodynamic parameters were examined. In both experiments survival was followed for five days. Results A single dose of caffeine at the initiation of sepsis did not alter survival. This single dose of caffeine did significantly increase in plasma levels of the chemokine KC six hours after the onset of sepsis compared to septic mice given normal saline. There were no changes in IL-6 or IL-10 levels in the caffeine groups. Peritoneal lavages performed 24 hours post-CLP showed no difference in the levels of IL-6, TNF, KC, MIP-1, IL-10 or the IL-1 receptor antagonist between caffeine and normal saline treated mice. Additionally, the lavages yielded similar numbers of cells (4.1×106 vehicle vs. 6.9×106 caffeine) and bacterial colony forming units (CFU, 4.1 million CFU vehicle vs. 2.8 million CFU caffeine). In the infusion group, caffeine also did not alter survival. However, caffeine infusion did increase heart rate prior to CLP, and prevented the decline in heart rate after CLP. Conclusion Caffeine increased heart rate in mice but does not impact cytokine

  7. Problem Behavior and Heart Rate Reactivity in Adopted Adolescents: Longitudinal and Concurrent Relations

    Science.gov (United States)

    Bimmel, Nicole; van IJzendoorn, Marinus H.; Bakermans-Kranenburg, Marian J.; Juffer, Femmie; De Geus, Eco J. C.

    2008-01-01

    The present longitudinal study examined resting heart rate and heart rate variability and reactivity to a stressful gambling task in adopted adolescents with aggressive, delinquent, or internalizing behavior problems and adopted adolescents without behavior problems (total N=151). Early-onset delinquent adolescents showed heart rate…

  8. Unobtrusive heart rate monitor based on a fiber specklegram sensor and a single-board computer

    Science.gov (United States)

    Benevides, Alessandro B.; Frizera, Anselmo; Cotrina, Anibal; Ribeiro, Moisés. R. N.; Segatto, Marcelo E. V.; Pontes, Maria José

    2015-09-01

    This paper proposes a portable and unobtrusive heart rate monitor based on fiber specklegram sensors. The proposed module uses the Raspberry Pi module to perform the image acquisition and the fiber specklegram sensor, which is based on multimode plastic optical fibers. The heart rate is obtained by welch power spectral density estimate and the heart beats are identified by means of a threshold analysis.

  9. Resting Heart Rate as Predictor for Left Ventricular Dysfunction and Heart Failure: The Multi-Ethnic Study of Atherosclerosis

    Science.gov (United States)

    Opdahl, Anders; Venkatesh, Bharath Ambale; Fernandes, Veronica R. S.; Wu, Colin O.; Nasir, Khurram; Choi, Eui-Young; Almeida, Andre L. C.; Rosen, Boaz; Carvalho, Benilton; Edvardsen, Thor; Bluemke, David A.; Lima, Joao A. C.

    2014-01-01

    OBJECTIVE To investigate the relationship between baseline resting heart rate and incidence of heart failure (HF) and global and regional left ventricular (LV) dysfunction. BACKGROUND The association of resting heart rate to HF and LV function is not well described in an asymptomatic multi-ethnic population. METHODS Participants in the Multi-Ethnic Study of Atherosclerosis had resting heart rate measured at inclusion. Incident HF was registered (n=176) during follow-up (median 7 years) in those who underwent cardiac MRI (n=5000). Changes in ejection fraction (ΔEF) and peak circumferential strain (Δεcc) were measured as markers of developing global and regional LV dysfunction in 1056 participants imaged at baseline and 5 years later. Time to HF (Cox model) and Δεcc and ΔEF (multiple linear regression models) were adjusted for demographics, traditional cardiovascular risk factors, calcium score, LV end-diastolic volume and mass in addition to resting heart rate. RESULTS Cox analysis demonstrated that for 1 bpm increase in resting heart rate there was a 4% greater adjusted relative risk for incident HF (Hazard Ratio: 1.04 (1.02, 1.06 (95% CI); Pheart rate was positively associated with deteriorating εcc and decrease in EF, even in analyses when all coronary heart disease events were excluded from the model. CONCLUSION Elevated resting heart rate is associated with increased risk for incident HF in asymptomatic participants in MESA. Higher heart rate is related to development of regional and global LV dysfunction independent of subclinical atherosclerosis and coronary heart disease. PMID:24412444

  10. CHANGES IN HEART RATE, HEART RATE VARIABILITY AND QT INTERVAL IN WOMEN WITH RHEUMATOID ARTHRITIS DURING RITUXIMAB TREATMENT

    Directory of Open Access Journals (Sweden)

    D. S. Novikova

    2014-01-01

    Full Text Available Rheumatoid arthritis (RA is a proven high cardiovascular risk disease. High heart rate (HR, lower heart rate variabil- ity (HRV, and increased QT interval are considered as predictors of cardiovascular events in patients with coronary heart disease, chronic heart failure, and diabetes mellitus. In RA, there is a pronounced rise in HR, a reduction in HRV, and an increase in QT interval mainly due to the factors reflecting the severity of the disease. Rituximab (RTM is successfully used to treat patients with high RA activity. At the same time there are only a few pieces of evidence for the effect of the drug on the cardiovascular system. Objective: to study changes in HR, HRV, and QT interval values obtained during electrocardiography (ECG Holter monitoring (ECG HM in RTM-treated women during a 6-month follow-up. Subjects and methods: The investigation enrolled 55 women (mean age 50 years with a definite diagnosis of RA and its high activity. The patients were examined 6 months after administration of RTM. The latter was infused intra- venously twice (500 and 1000 mg in 22% and 78% of the patients, respectively during therapy with disease-modifying antirheumatic and non-steroidal anti-inflammatory drugs and glucocorticoids. The RA patients were divided into two groups: 1 a satisfactory/good effect of RTM according to the EULAR criteria (n = 41; 2 no effect (n = 14. Analysis of 24-hour ECG HM yielded the values of HR and mean duration of corrected QT interval (QTc. The tim- ing HRV values obtained at ECG HM were standardized from age and mean HR (SDNNn, RMSSDn, and pNN50n. Results. The baseline HRmin and HRmean values were higher and SDNNn was lower in the RA patients in Group 1 than those in Group 2 (p < 0.05. In Group 1, RTM therapy was accompanied by a reduction in HRmean and HRmin by 8% and by an increase in SDNNn by 3%, RMSSDn by 26%, and pNN50n by 33% whereas no significant changes in HR and HRV were found in Group 2. The RTM therapy

  11. Effect of xylazine and ketamine on blood pressure, heart rate and respiratory rate in rabbits.

    Science.gov (United States)

    Sanford, T D; Colby, E D

    1980-06-01

    New Zealand white and New Zeland white-Dutch Belted cross rabbits of both sexes were anesthetized using xylazine and ketamine alone and in combination while blood pressure, heart and respiratory rates were monitored. Blood pressure effects were measured from the aortic arch by a cannula implant through the left carotid artery. Ketamine-xylazine in combination at 35 and 5 mg/kg body weight, respectively, produced 45-60 minutes of surgical plane anesthesia. Anesthesia was induced in approximately 10 minutes. The average initial blood pressure drop was complete in 10 minutes and was 30%. Heart and respiratory rates dropped 19% and 77%, respectively, in the same time span. An additional blood pressure drop of 6-7% occurred as consciousness was regained. Blood pressure recovery was nearly complete (normal) about 6 hours following injection of the drug combination.

  12. Sound-Intensity Feedback During Running Reduces Loading Rates and Impact Peak.

    Science.gov (United States)

    Tate, Jeremiah J; Milner, Clare E

    2017-08-01

    Study Design Controlled laboratory study, within-session design. Background Gait retraining has been proposed as an effective intervention to reduce impact loading in runners at risk of stress fractures. Interventions that can be easily implemented in the clinic are needed. Objective To assess the immediate effects of sound-intensity feedback related to impact during running on vertical impact peak, peak vertical instantaneous loading rate, and vertical average loading rate. Methods Fourteen healthy, college-aged runners who ran at least 9.7 km/wk participated (4 male, 10 female; mean ± SD age, 23.7 ± 2.0 years; height, 1.67 ± 0.08 m; mass, 60.9 ± 8.7 kg). A decibel meter provided real-time sound-intensity feedback of treadmill running via an iPad application. Participants were asked to reduce the sound intensity of running while receiving continuous feedback for 15 minutes, while running at their self-selected preferred speed. Baseline and follow-up ground reaction force data were collected during overground running at participants' self-selected preferred running speed. Results Dependent t tests indicated a statistically significant reduction in vertical impact peak (1.56 BW to 1.13 BW, P≤.001), vertical instantaneous loading rate (95.48 BW/s to 62.79 BW/s, P = .001), and vertical average loading rate (69.09 BW/s to 43.91 BW/s, P≤.001) after gait retraining, compared to baseline. Conclusion The results of the current study support the use of sound-intensity feedback during treadmill running to immediately reduce loading rate and impact force. The transfer of within-session reductions in impact peak and loading rates to overground running was demonstrated. Decreases in loading were of comparable magnitude to those observed in other gait retraining methods. J Orthop Sports Phys Ther 2017;47(8):565-569. Epub 6 Jul 2017. doi:10.2519/jospt.2017.7275.

  13. Effect of atrioventricular conduction on heart rate variability

    KAUST Repository

    Ahmad, Talha Jamal

    2011-08-01

    This paper discusses the effect of atrioventricular conduction time (AVCT) on the short-term Heart Rate Variability (HRV) by computing HRV parameters using intervals between the onsets of successive P waves (PP time series) for three groups: normal, arrhythmia and sudden cardiac death (SCD) patients. A very precise wavelet transform based ECG delineator was developed to detect PP, PR and RR time series. Mean PR variation in arrhythmia and SCD group was found to be significantly high as compared to the normal group. It was observed that when PR variations in arrhythmia and SCD cases crossed a certain threshold, RR variability no longer provided a very accurate estimate of HRV. In such cases, PP variability was able to provide a better assessment of HRV. © 2011 IEEE.

  14. Decreased heart rate variability responses during early postoperative mobilization

    DEFF Research Database (Denmark)

    Jans, Øivind; Brinth, Louise; Kehlet, Henrik

    2015-01-01

    BACKGROUND: Intact orthostatic blood pressure regulation is essential for early mobilization after surgery. However, postoperative orthostatic hypotension and intolerance (OI) may delay early ambulation. The mechanisms of postoperative OI include impaired vasopressor responses relating to postope......BACKGROUND: Intact orthostatic blood pressure regulation is essential for early mobilization after surgery. However, postoperative orthostatic hypotension and intolerance (OI) may delay early ambulation. The mechanisms of postoperative OI include impaired vasopressor responses relating...... to postoperative autonomic dysfunction. Thus, based on a previous study on haemodynamic responses during mobilization before and after elective total hip arthroplasty (THA), we performed secondary analyses of heart rate variability (HRV) and aimed to identify possible abnormal postoperative autonomic responses...... in relation to postural change. METHODS: A standardized mobilization protocol before, 6 and 24 h after surgery was performed in 23 patients scheduled for elective THA. Beat-to-beat arterial blood pressure was measured by photoplethysmography and HRV was derived from pulse wave interbeat intervals and analysed...

  15. Heart rate variability analysis with the R package RHRV

    CERN Document Server

    García Martínez, Constantino Antonio; Vila, Xosé A; Lado Touriño, María José; Rodríguez-Liñares, Leandro; Rodríguez Presedo, Jesús María; Méndez Penín, Arturo José

    2017-01-01

    This book introduces readers to the basic concepts of Heart Rate Variability (HRV) and its most important analysis algorithms using a hands-on approach based on the open-source RHRV software. HRV refers to the variation over time of the intervals between consecutive heartbeats. Despite its apparent simplicity, HRV is one of the most important markers of the autonomic nervous system activity and it has been recognized as a useful predictor of several pathologies. The book discusses all the basic HRV topics, including the physiological contributions to HRV, clinical applications, HRV data acquisition, HRV data manipulation and HRV analysis using time-domain, frequency-domain, time-frequency, nonlinear and fractal techniques. Detailed examples based on real data sets are provided throughout the book to illustrate the algorithms and discuss the physiological implications of the results. Offering a comprehensive guide to analyzing beat information with RHRV, the book is intended for masters and Ph.D. students in v...

  16. Automated Fetal Heart Rate Analysis in Labor: Decelerations and Overshoots

    Science.gov (United States)

    Georgieva, A. E.; Payne, S. J.; Moulden, M.; Redman, C. W. G.

    2010-10-01

    Electronic fetal heart rate (FHR) recording is a standard way of monitoring fetal health in labor. Decelerations and accelerations usually indicate fetal distress and normality respectively. But one type of acceleration may differ, namely an overshoot that may atypically reflect fetal stress. Here we describe a new method for detecting decelerations, accelerations and overshoots as part of a novel system for computerized FHR analysis (OxSyS). There was poor agreement between clinicians when identifying these FHR features visually, which precluded setting a gold standard of interpretation. We therefore introduced `modified' Sensitivity (SE°) and `modified' Positive Predictive Value (PPV°) as appropriate performance measures with which the algorithm was optimized. The relation between overshoots and fetal compromise in labor was studied in 15 cases and 15 controls. Overshoots showed promise as an indicator of fetal compromise. Unlike ordinary accelerations, overshoots cannot be considered to be reassuring features of fetal health.

  17. Algorithms for Computerized Fetal Heart Rate Diagnosis with Direct Reporting

    Directory of Open Access Journals (Sweden)

    Kazuo Maeda

    2015-06-01

    Full Text Available Aims: Since pattern classification of fetal heart rate (FHR was subjective and enlarged interobserver difference, objective FHR analysis was achieved with computerized FHR diagnosis. Methods: The computer algorithm was composed of an experts’ knowledge system, including FHR analysis and FHR score calculation, and also of an objective artificial neural network system with software. In addition, a FHR frequency spectrum was studied to detect ominous sinusoidal FHR and the loss of baseline variability related to fetal brain damage. The algorithms were installed in a central-computerized automatic FHR monitoring system, which gave the diagnosis rapidly and directly to the attending doctor. Results: Clinically perinatal mortality decreased significantly and no cerebral palsy developed after introduction of the centralized system. Conclusion: The automatic multichannel FHR monitoring system improved the monitoring, increased the objectivity of FHR diagnosis and promoted clinical results.

  18. Heart rate variability is reduced during acute uncomplicated diverticulitis

    DEFF Research Database (Denmark)

    Huang, Chenxi; Alamili, Mahdi; Rosenberg, Jacob

    2016-01-01

    BACKGROUND: The aim of the present study was to report the trajectory of heart rate variability (HRV) indices during a low-grade acute inflammation and their associations to biomarkers for infection. METHODS: Twelve patients with uncomplicated acute diverticulitis completed this observational study......, which composed of 3 sessions of continuous HRV recording from 9 PM to 8 AM during ongoing diverticulitis and at complete remission (baseline). The blood samples were collected at each study session measuring C-reactive protein (CRP) and leukocytes. RESULTS: This study showed that the trajectories...... of the HRV indices were decreased both in time and frequency domains during acute diverticulitis compared to baseline. In particular, the indices reflecting the balance of sympathetic and parasympathetic activities were affected: standard deviation of normal-to-normal beats (P = .003), low-frequency power (P...

  19. [Comparison of heart rate variability measurements between ballistocardiogram and electrocardiography].

    Science.gov (United States)

    Wang, Kun; Zhu, Tiangang; Zhang, Xianwen; Yu, Chao; Cao, Xinrong; Tang, Jintian; Wan, Zheng

    2015-05-01

    To compare the heart rate variability (HRV) measurements between ballistocardiogram (BCG) and electrocardiography (ECG). The signals of BCG and ECG of 21 patients were collected synchronously. JJ intervals of BCG and RR intervals of ECG were used to calculate the cardiac periods. The parameters of HRV analysis were calculated in time domain analysis, frequency domain analysis and nonlinear analysis. The results derived from BCG and ECG were compared. The parameters of HRV analysis calculated from BCG and ECG had high similarity. The correlation coefficients of SDNN, TP, LF, HF and SD2 between the BCG and ECG methods were high (r = 1). The correlation coefficients of rMSSD and SD2 were 0.99 and of PNN50 and LF/HF were 0.98 between the two methods. HRV analysis results derived from the two methods were similar (P > 0.05). HRV could also be measured reliably by calculating the JJ interval from BCG.

  20. Heart rate variability and motion sickness during forklift simulator driving.

    Science.gov (United States)

    Zużewicz, Krystyna; Saulewicz, Antoni; Konarska, Maria; Kaczorowski, Zbigniew

    2011-01-01

    The goal of the study was to determine the effect of a 1-h hour long forklift truck virtual simulator driving on the mechanism of autonomic heart rate (HR) regulation in operators. The participants were divided into 2 subgroups: subjects with no definite inclination to motion sickness (group A) and subjects with a definite inclination to motion sickness (group B). Holter monitoring of electrocardiogram (ECG) signal was carried out in all subjects during the virtual simulator driving. For 12 consecutive epochs of ECG signal, HR variability analysis was conducted in time and frequency domains. In subjects with a definite inclination to motion sickness after ~30 min of the driving, changes in parameter values were found indicating an increase in sympathetic and parasympathetic activity with parasympathetic dominance.

  1. Wearable depression monitoring system with heart-rate variability.

    Science.gov (United States)

    Roh, Taehwan; Hong, Sunjoo; Yoo, Hoi-Jun

    2014-01-01

    A wearable depression monitoring system is proposed with an application-specific system-on-chip (SoC) solution. The SoC is designed to accelerate the filtering and feature extraction of heart-rate variability (HRV) from the electrocardiogram (ECG). Thanks to the SoC solution and planar-fashionable circuit board (P-FCB), the monitoring system becomes a low-power wearable system. Its dimension is 14cm × 7cm with 5mm thickness covering the chest band for convenient usage. In addition, with 3.7V 500mAh battery, its lifetime is at least 10 hours. For user's convenience, the system is interfacing to smart phones through Bluetooth communication. With the features of the HRV and Beck depression inventory (BDI), the smart phone application trains and classifies the user's depression scale with 71% of accuracy.

  2. Extraction of heart rate variability from smartphone photoplethysmograms.

    Science.gov (United States)

    Peng, Rong-Chao; Zhou, Xiao-Lin; Lin, Wan-Hua; Zhang, Yuan-Ting

    2015-01-01

    Heart rate variability (HRV) is a useful clinical tool for autonomic function assessment and cardiovascular diseases diagnosis. It is traditionally calculated from a dedicated medical electrocardiograph (ECG). In this paper, we demonstrate that HRV can also be extracted from photoplethysmograms (PPG) obtained by the camera of a smartphone. Sixteen HRV parameters, including time-domain, frequency-domain, and nonlinear parameters, were calculated from PPG captured by a smartphone for 30 healthy subjects and were compared with those derived from ECG. The statistical results showed that 14 parameters (AVNN, SDNN, CV, RMSSD, SDSD, TP, VLF, LF, HF, LF/HF, nLF, nHF, SD1, and SD2) from PPG were highly correlated (r > 0.7, P maximum first derivative (M1D), maximum second derivative (M2D), and tangent intersection (TI). The results showed that M2D and TI algorithms had the best performance. These results suggest that the smartphone might be used for HRV measurement.

  3. Breathing frequency bias in fractal analysis of heart rate variability.

    Science.gov (United States)

    Perakakis, Pandelis; Taylor, Michael; Martinez-Nieto, Eduardo; Revithi, Ioanna; Vila, Jaime

    2009-09-01

    Detrended Fluctuation Analysis (DFA) is an algorithm widely used to determine fractal long-range correlations in physiological signals. Its application to heart rate variability (HRV) has proven useful in distinguishing healthy subjects from patients with cardiovascular disease. In this study we examined the effect of respiratory sinus arrhythmia (RSA) on the performance of DFA applied to HRV. Predictions based on a mathematical model were compared with those obtained from a sample of 14 normal subjects at three breathing frequencies: 0.1Hz, 0.2Hz and 0.25Hz. Results revealed that: (1) the periodical properties of RSA produce a change of the correlation exponent in HRV at a scale corresponding to the respiratory period, (2) the short-term DFA exponent is significantly reduced when breathing frequency rises from 0.1Hz to 0.2Hz. These findings raise important methodological questions regarding the application of fractal measures to short-term HRV.

  4. Alterations in the heart rate and activity rhythms of three orbital astronauts on a space mission

    Science.gov (United States)

    Liu, Zhizhen; Wan, Yufeng; Zhang, Lin; Tian, Yu; Lv, Ke; Li, Yinghui; Wang, Chunhui; Chen, Xiaoping; Chen, Shanguang; Guo, Jinhu

    2015-01-01

    Environmental factors in space are dramatically different from those on Earth. The spaceflight environment has been known to influence human physiology and behavior on orbital missions. In this study, we investigated alterations in the diurnal rhythms of activity and heart rate of three Chinese astronauts on a space mission. An analysis of the heart rate data showed a significant decrease in heart rate amplitudes during flight in all three subjects. The heart rate amplitudes of all the three astronauts were significantly dampened during flight, and the minimum as well as the maximum value of heart rate increased after flight. A phase shift in heart rate was observed in one of the three astronauts after flight. These results demonstrate the influence of spaceflight on heart physiology and function. In addition, a significant decrease in body trunk activity and rhythmicity occurred during flight, demonstrating that the spaceflight environment disturbs motion adaptation and diurnal activity rhythms.

  5. Resting and postexercise heart rate variability in professional handball players.

    Science.gov (United States)

    Kayacan, Yildirim; Yildiz, Sedat

    2016-03-01

    The aim of this study was to evaluate heart rate variability (HRV) in professional handball players during rest and following a 5 min mild jogging exercise. For that purpose, electrocardiogram (ECG) of male handball players (N.=12, mean age 25±3.95 years) and sedentary controls (N.=14, mean age 23.5±2.95 years) were recorded for 5 min at rest and just after 5 min of mild jogging. ECGs were recorded and following HRV parameters were calculated: time-domain variables such as heart rate (HR), average normal-to-normal RR intervals, standard deviation of normal-to-normal RR intervals, square root of the mean of the squares of differences between adjacent NN intervals, percentage of differences between adjacent NN intervals that are greater than 50 milliseconds (pNN50), and frequency-domain variables such as very low frequency, low (LF) and high frequency (HF) of the power and LF/HF ratio. Unpaired t-test was used to find out differences among groups while paired t-test was used for comparison of each group for pre- and postjogging HRV. Pearson correlations were carried out to find out the relationships between the parameters. Blood pressures were not different between handball players and sedentary controls but exercise increased systolic blood pressure (Phandball players (Phandball players (Phandball players in response to a mild, short-time (5 min) jogging exercise. However, in sedentary subjects, either the sympathetic regulation of the autonomous nervous system increased or vagal withdrawal occurred.

  6. Heart rate variability as a biomarker for epilepsy seizure prediction.

    Science.gov (United States)

    Moridani, M K; Farhadi, H

    2017-01-01

    Epilepsy is a neurological disorder that causes seizures of many different types. Recent research has shown that epileptic seizures can be predicted by using the electrocardiogrami instead of the electroencephalogram. In this study, we used the heart rate variability that is generated by the fluctuating balance of sympathetic and parasympathetic nervous systems to predict epileptic seizures. We studied 11 epilepsy patients to predict the seizure interval. With regar tos the fact that HRV signals are nonstationary, our analysis focused on linear features in the time and frequency domain of HRV signal such as RR Interval (RRI), mean heart rate (HR), high-frequency (HF) (0.15-0.40 Hz) and low-frequency (LF) (0.04-0.15 Hz), as well as LF/HF. Also, quantitative analyses of Poincaré plot features (SD1, SD2, and SD1/SD2 ratio) were performed. HRV signal was divided into intervals of 5 minutes. In each segment linear and nonlinear features were extracted and then the amount of each segment compared to the previous segment using a threshold. Finally, we evaluated the performance of our method using specificity and sensitivity. During seizures, mean HR, LF/HF, and SD2/SD1 ratio significantly increased while RRI significantly decreased. Significant differences between two groups were identified for several HRV features. Therefore, these parameters can be used as a useful feature to discriminate a seizure from a non-seizure The seizure prediction algorithm proposed based on HRV achieved 88.3% sensitivity and 86.2 % specificity. These results indicate that the HRV signal contains valuable information and can be a predictor for epilepsy seizure. Although our results in comparison with EEG ares a little bit weaker, the recording of ECG is much easier and faster than EEG. Also, our finding showed the results of this study are considerably better than recent research based on ECG (Tab. 1, Fig. 10, Ref. 17).

  7. Differences in heart rate variability during haemodialysis and haemofiltration.

    Science.gov (United States)

    Genovesi, Simonetta; Bracchi, Oscar; Fabbrini, Paolo; Luisetto, Elena; Viganò, Maria Rosa; Lucini, Daniela; Malacarne, Mara; Stella, Andrea; Pagani, Massimo

    2007-08-01

    The aim of our study was to evaluate whether convective (haemofiltration, Hf) and diffusive (haemodialysis, Hd) dialysis techniques induce different patterns of long- and short-term autonomic adjustments in haemodynamically stable dialysis patients. Ten haemodynamically stable Hd patients were studied. Each patient underwent a block of six Hd sessions, then was switched to six Hf. During the last session of each dialytic treatment, continuous beat to beat measurements of systolic arterial pressure (SAP) and heart rate (HR) were performed. Spectral analysis of heart rate variability (HRV) was made before and during the treatment to evaluate the modification of autonomic nervous system activity. Baseline values of plasma sodium, body weight, HR and SAP were not different for the two considered methods of dialysis, while the baseline values of normalized LF were significantly higher in Hf as compared to Hd and the opposite was observed for HF powers (P < 0.001). Sodium balance and body weight loss per hour did not differ between Hd and Hf while body temperature was kept constant in all sessions. Throughout the dialytic procedures, with both techniques, SAP was constant, while HR diminished from the first hour till the end of the procedure (P < 0.05). An increase in LF (and decrease in HF) was noticed only in the case of Hd, considering normalized units (P < 0.05). These selective changes were maintained also during the recovery after the procedure. The spectral analysis of RR interval variability during Hd and Hf suggests a potential autonomic advantage with Hf, to be added to the well-recognized intrinsic greater haemodynamic stability.

  8. Venipuncture procedure affects heart rate variability and chronotropic response.

    Science.gov (United States)

    Kliszczewicz, Brian; Esco, Michael R; E Bechke, Emily; Feito, Yuri; M Williamson, Cassie; Brown, Danielle; Price, Brandi

    2017-10-01

    Heart rate variability (HRV) has been shown to be influenced by several factors such as noise, sleep status, light, and emotional arousal; however, little evidence is available concerning autonomic responses to a venipuncture. The purpose of this study was to investigate changes of HRV indexes and heart rate (HR) during and following a venipuncture procedure among healthy individuals. 33 healthy individuals (22.8 ± 0.56 years, 167 ± 1.56 cm, 69.5 ± 2.61 kg) participated. Testing included 10-minute HRV analysis prior to the venipuncture, a 1-minute venipuncture procedure followed by a 10-minute analysis of HRV, and a total recording of 21 minutes. The first 5 minutes of the 21-minute recordings were discarded, and the remaining 5 minutes of the resting segment was analyzed (PRE), and the last 5 minutes of the 21-minute recording (POST). The log transformation of the time domain root mean squared of successive differences (lnRMSSD) and the frequency domains of high frequency (lnHF) and low frequency (lnLF) and LF/HF ratio (lnLF/HF) were used to quantify autonomic activity. HR was measured in 1-minute segments at 2 minutes prior (PRE), venipuncture (STICK), and post (P1-5). HR significantly increased at STICK (P = 0.002), and fell below resting at P-5 (P < 0.001). lnRMSSD and lnHF increased significantly by POST (P < 0.001, P = 0.005). lnLF/HF ratio significantly decreased at POST (P = 0.047), while no significant changes occurred for lnLF (P = 0.590). HRV and HR are influenced for 10 minutes following the venipuncture procedure. Practitioners and researchers who are interested in collecting blood and measuring HRV need to account for the influence of the venipuncture. © 2017 Wiley Periodicals, Inc.

  9. Heart rate variability in porcine progressive peritonitis-induced sepsis

    Directory of Open Access Journals (Sweden)

    Dagmar eJarkovska

    2016-01-01

    Full Text Available Accumulating evidence suggests that heart rate variability (HRV alterations could serve as an indicator of sepsis progression and outcome, however, the relationships of HRV and major pathophysiological processes of sepsis remain unclear. Therefore, in this experimental study HRV was investigated in a clinically relevant long-term porcine model of severe sepsis/septic shock. HRV was analyzed by several methods and the parameters were correlated with pathophysiological processes of sepsis.In 16 anesthetized, mechanically ventilated and instrumented domestic pigs of either gender, sepsis was induced by fecal peritonitis. Experimental subjects were screened up to the refractory shock development or death. ECG was continuously recorded throughout the experiment, afterwards RR intervals were detected and HRV parameters computed automatically using custom made measurement and analysis MATLAB routines. In all septic animals, progressive hyperdynamic septic shock developed. The statistical measures of HRV, geometrical measures of HRV and Poincaré plot analysis revealed a pronounced reduction of HRV that developed quickly upon the onset of sepsis and was maintained throughout the experiment. The frequency domain analysis demonstrated a decrease in the high frequency component and increase in the low frequency component together with an increase of the low/high frequency component ratio. The reduction of HRV parameters preceded sepsis-associated hemodynamic changes including heart rate increase or shock progression.In a clinically relevant porcine model of peritonitis-induced progressive septic shock, reduction of HRV parameters heralded sepsis development. HRV reduction was associated with a pronounced parasympathetic inhibition and a shift of sympathovagal balance. Early reduction of HRV may serve as a non-invasive and sensitive marker of systemic inflammatory syndrome, thereby widening the therapeutic window for early interventions.

  10. Cuff-Free Blood Pressure Estimation Using Pulse Transit Time and Heart Rate.

    Science.gov (United States)

    Wang, Ruiping; Jia, Wenyan; Mao, Zhi-Hong; Sclabassi, Robert J; Sun, Mingui

    2014-10-01

    It has been reported that the pulse transit time (PTT), the interval between the peak of the R-wave in electrocardiogram (ECG) and the fingertip photoplethysmogram (PPG), is related to arterial stiffness, and can be used to estimate the systolic blood pressure (SBP) and diastolic blood pressure (DBP). This phenomenon has been used as the basis to design portable systems for continuously cuff-less blood pressure measurement, benefiting numerous people with heart conditions. However, the PTT-based blood pressure estimation may not be sufficiently accurate because the regulation of blood pressure within the human body is a complex, multivariate physiological process. Considering the negative feedback mechanism in the blood pressure control, we introduce the heart rate (HR) and the blood pressure estimate in the previous step to obtain the current estimate. We validate this method using a clinical database. Our results show that the PTT, HR and previous estimate reduce the estimated error significantly when compared to the conventional PTT estimation approach (p<0.05).

  11. Rate Control Management of Atrial Fibrillation: May a Mathematical Model Suggest an Ideal Heart Rate?

    CERN Document Server

    Anselmino, Matteo; Camporeale, Carlo; Saglietto, Andrea; Gaita, Fiorenzo; Ridolfi, Luca

    2015-01-01

    Background. Despite the routine prescription of rate control therapy for atrial fibrillation (AF), clinical evidence demonstrating a heart rate target is lacking. Aim of the present study was to run a mathematical model simulating AF episodes with a different heart rate (HR) to predict hemodynamic parameters for each situation. Methods. The lumped model, representing the pumping heart together with systemic and pulmonary circuits, was run to simulate AF with HR of 50, 70, 90, 110 and 130 bpm, respectively. Results. Left ventricular pressure increased by 56.7%, from 33.92+-37.56 mmHg to 53.15+-47.56 mmHg, and mean systemic arterial pressure increased by 27.4%, from 82.66+-14.04 mmHg to 105.29+-7.63 mmHg, at the 50 and 130 bpm simulations, respectively. Stroke volume (from 77.45+-8.5 to 39.09+-8.08 mL), ejection fraction (from 61.1+-4.4 to 39.32+-5.42%) and stroke work (SW, from 0.88+-0.04 to 0.58+-0.09 J) decreased by 49.5, 35.6 and 34.2%, at the 50 and 130 bpm simulations, respectively. In addition, oxygen co...

  12. The predictive value of resting heart rate following osmotherapy in brain injury: back to basics

    Directory of Open Access Journals (Sweden)

    Hasanpour Mir Mahsa

    2012-12-01

    Full Text Available Abstract Background The importance of resting heart rate as a prognostic factor was described in several studies. An elevated heart rate is an independent risk factor for adverse cardiovascular events and total mortality in patients with coronary artery disease, chronic heart failure, and the general population. Also heart rate is elevated in the Multi Organ Dysfunction Syndrome (MODS and the mortality due to MODS is highly correlated with inadequate sinus tachycardia. To evaluate the value of resting heart rate in predicting mortality in patients with traumatic brain injury along scoring systems like Acute Physiology and Chronic Health Evaluation(APACHE II, Sequential Organ Failure Assessment (SOFA and Glasgow Coma Score (GCS. Method By analyzing data which was collected from an open labeled randomized clinical trial that compared the different means of osmotherapy (mannitol vs bolus or infusion hypertonic saline, heart rate, GCS, APACHE II and SOFA score were measured at baseline and daily for 7 days up to 60 days and the relationship between elevated heart rate and mortality during the first 7 days and 60th day were assessed. Results After adjustments for confounding factors, although there was no difference in mean heart rate between either groups of alive and expired patients, however, we have found a relative correlation between 60th day mortality rate and resting heart rate (P=0.07. Conclusion Heart rate can be a prognostic factor for estimating mortality rate in brain injury patients along with APACHE II and SOFA scores in patients with brain injury.

  13. Keeping Pace with Your Eating: Visual Feedback Affects Eating Rate in Humans.

    Directory of Open Access Journals (Sweden)

    Laura L Wilkinson

    Full Text Available Deliberately eating at a slower pace promotes satiation and eating quickly has been associated with a higher body mass index. Therefore, understanding factors that affect eating rate should be given high priority. Eating rate is affected by the physical/textural properties of a food, by motivational state, and by portion size and palatability. This study explored the prospect that eating rate is also influenced by a hitherto unexplored cognitive process that uses ongoing perceptual estimates of the volume of food remaining in a container to adjust intake during a meal. A 2 (amount seen; 300 ml or 500 ml x 2 (amount eaten; 300 ml or 500 ml between-subjects design was employed (10 participants in each condition. In two 'congruent' conditions, the same amount was seen at the outset and then subsequently consumed (300 ml or 500 ml. To dissociate visual feedback of portion size and actual amount consumed, food was covertly added or removed from a bowl using a peristaltic pump. This created two additional 'incongruent' conditions, in which 300 ml was seen but 500 ml was eaten or vice versa. We repeated these conditions using a savoury soup and a sweet dessert. Eating rate (ml per second was assessed during lunch. After lunch we assessed fullness over a 60-minute period. In the congruent conditions, eating rate was unaffected by the actual volume of food that was consumed (300 ml or 500 ml. By contrast, we observed a marked difference across the incongruent conditions. Specifically, participants who saw 300 ml but actually consumed 500 ml ate at a faster rate than participants who saw 500 ml but actually consumed 300 ml. Participants were unaware that their portion size had been manipulated. Nevertheless, when it disappeared faster or slower than anticipated they adjusted their rate of eating accordingly. This suggests that the control of eating rate involves visual feedback and is not a simple reflexive response to orosensory stimulation.

  14. Keeping Pace with Your Eating: Visual Feedback Affects Eating Rate in Humans.

    Science.gov (United States)

    Wilkinson, Laura L; Ferriday, Danielle; Bosworth, Matthew L; Godinot, Nicolas; Martin, Nathalie; Rogers, Peter J; Brunstrom, Jeffrey M

    2016-01-01

    Deliberately eating at a slower pace promotes satiation and eating quickly has been associated with a higher body mass index. Therefore, understanding factors that affect eating rate should be given high priority. Eating rate is affected by the physical/textural properties of a food, by motivational state, and by portion size and palatability. This study explored the prospect that eating rate is also influenced by a hitherto unexplored cognitive process that uses ongoing perceptual estimates of the volume of food remaining in a container to adjust intake during a meal. A 2 (amount seen; 300 ml or 500 ml) x 2 (amount eaten; 300 ml or 500 ml) between-subjects design was employed (10 participants in each condition). In two 'congruent' conditions, the same amount was seen at the outset and then subsequently consumed (300 ml or 500 ml). To dissociate visual feedback of portion size and actual amount consumed, food was covertly added or removed from a bowl using a peristaltic pump. This created two additional 'incongruent' conditions, in which 300 ml was seen but 500 ml was eaten or vice versa. We repeated these conditions using a savoury soup and a sweet dessert. Eating rate (ml per second) was assessed during lunch. After lunch we assessed fullness over a 60-minute period. In the congruent conditions, eating rate was unaffected by the actual volume of food that was consumed (300 ml or 500 ml). By contrast, we observed a marked difference across the incongruent conditions. Specifically, participants who saw 300 ml but actually consumed 500 ml ate at a faster rate than participants who saw 500 ml but actually consumed 300 ml. Participants were unaware that their portion size had been manipulated. Nevertheless, when it disappeared faster or slower than anticipated they adjusted their rate of eating accordingly. This suggests that the control of eating rate involves visual feedback and is not a simple reflexive response to orosensory stimulation.

  15. Keeping Pace with Your Eating: Visual Feedback Affects Eating Rate in Humans

    Science.gov (United States)

    Bosworth, Matthew L.; Godinot, Nicolas; Martin, Nathalie; Rogers, Peter J.; Brunstrom, Jeffrey M.

    2016-01-01

    Deliberately eating at a slower pace promotes satiation and eating quickly has been associated with a higher body mass index. Therefore, understanding factors that affect eating rate should be given high priority. Eating rate is affected by the physical/textural properties of a food, by motivational state, and by portion size and palatability. This study explored the prospect that eating rate is also influenced by a hitherto unexplored cognitive process that uses ongoing perceptual estimates of the volume of food remaining in a container to adjust intake during a meal. A 2 (amount seen; 300ml or 500ml) x 2 (amount eaten; 300ml or 500ml) between-subjects design was employed (10 participants in each condition). In two ‘congruent’ conditions, the same amount was seen at the outset and then subsequently consumed (300ml or 500ml). To dissociate visual feedback of portion size and actual amount consumed, food was covertly added or removed from a bowl using a peristaltic pump. This created two additional ‘incongruent’ conditions, in which 300ml was seen but 500ml was eaten or vice versa. We repeated these conditions using a savoury soup and a sweet dessert. Eating rate (ml per second) was assessed during lunch. After lunch we assessed fullness over a 60-minute period. In the congruent conditions, eating rate was unaffected by the actual volume of food that was consumed (300ml or 500ml). By contrast, we observed a marked difference across the incongruent conditions. Specifically, participants who saw 300ml but actually consumed 500ml ate at a faster rate than participants who saw 500ml but actually consumed 300ml. Participants were unaware that their portion size had been manipulated. Nevertheless, when it disappeared faster or slower than anticipated they adjusted their rate of eating accordingly. This suggests that the control of eating rate involves visual feedback and is not a simple reflexive response to orosensory stimulation. PMID:26828922

  16. A new approach to the measurement of heart rate in patients with chronic heart failure-heart rate performance index: an observational study.

    Science.gov (United States)

    Akyüz, Aydın; Alpsoy, Şeref; Akkoyun, Dursun Çayan; Güler, Niyazi

    2013-05-01

    In order to evaluate the utility of the heart rate performance index (HRPI), which is obtained by dividing HR mean by the difference of HR max and HR min in the context of Holter monitoring, we sought to determine whether there was any correlation or relationship between the HRPI and LVEF values as determined by echocardiography and to compare the HRPI between the study and control groups. This study is a cross-sectional, controlled observational study. Thirty-two patients with symptomatic or asymptomatic left ventricular systolic dysfunction (LVEF heart failure (CHF) were included as a control group. In the study group, 10 patients were in NYHA class I (31.2%), 12 - were in NYHA class II (37.6%) and 10 - were in NYHA class III (31.2%). Heart rate analysis was measured using 24-hour Holter ambulatory electrocardiography. To determine the HRPI, the difference between maximum (HR max) and minimum heart rate (HR min) was divided by mean heart rate (HR mean) (beats/minute): HRPI=(HR max-HR min) / HR mean. Statistical analysis was performed using t-test for independent samples, Mann-Whitney U test, Chi-square test, Kruskal-Wallis test, Pearson's correlation and linear regression analyses. The HRPI index value was markedly decreased [0.83 (0.58-1.1) and 1.10 (0.74-1.3), pheart rate derivatives (unstandardized β=42.43 95% CI: 21.98-50.51, p=0.231). According to our findings, patients with CHF exhibited higher HR mean values, reduced HR max-min values and significantly decreased HRPI values. There is a positive correlation between HRPI and LVEF, a decreased HRPI is associated with a decreased LVEF, but there is no relationship between these two variables. Therefore, HRPI values may represent a viable option for assessing daily exercise activity and potentially sympathetic activation in patients with CHF. The assessment of HRPI may be helpful the evaluation of CHF patients, as well as resting HR.

  17. Resonance of about-weekly human heart rate rhythm with solar activity change.

    Science.gov (United States)

    Cornelissen, G; Halberg, F; Wendt, H W; Bingham, C; Sothern, R B; Haus, E; Kleitman, E; Kleitman, N; Revilla, M A; Revilla, M; Breus, T K; Pimenov, K; Grigoriev, A E; Mitish, M D; Yatsyk, G V; Syutkina, E V

    1996-12-01

    In several human adults, certain solar activity rhythms may influence an about 7-day rhythm in heart rate. When no about-weekly feature was found in the rate of change in sunspot area, a measure of solar activity, the double amplitude of a circadian heart rate rhythm, approximated by the fit of a 7-day cosine curve, was lower, as was heart rate corresponds to about-weekly features in solar activity and/or relates to a sunspot cycle.

  18. Variability in heart rate recovery measurements over 1 year in healthy, middle-aged adults.

    Science.gov (United States)

    Mellis, M G; Ingle, L; Carroll, S

    2014-02-01

    This study assessed the longer-term (12-month) variability in post-exercise heart rate recovery following a submaximal exercise test. Longitudinal data was analysed for 97 healthy middle-aged adults (74 male, 23 female) from 2 occasions, 12 months apart. Participants were retrospectively selected if they had stable physical activity habits, submaximal treadmill fitness and anthropometric measurements between the 2 assessment visits. A submaximal Bruce treadmill test was performed to at least 85% age-predicted maximum heart rate. Absolute heart rate and Δ heart rate recovery (change from peak exercise heart rate) were recorded for 1 and 2 min post-exercise in an immediate supine position. Heart rate recovery at both time-points was shown to be reliable with intra-class correlation coefficient values ≥ 0.714. Absolute heart rate 1-min post-exercise showed the strongest agreement between repeat tests (r = 0.867, P heart rate values rather than Δ heart rate recovery, and for 1-min rather than 2-min post-exercise recovery time points. Log-transformed values generated better variability with acceptable coefficient of variation for all measures (2.2-10%). Overall, 1 min post-exercise heart rate recovery data had least variability over the 12-month period in apparently healthy middle-aged adults. © Georg Thieme Verlag KG Stuttgart · New York.

  19. [The exercise training restores the heart rate variability in heart failure patients. A systematic review].

    Science.gov (United States)

    Segovia, Victoria; Manterola, Carlos; González, Marcelo; Rodríguez-Núñez, Iván

    Cardiovascular diseases are a significant cause of morbidity and mortality in the general population. In this sense, the autonomic imbalance is the cornerstone of the pathophysiology underlying the development of these diseases. The aim of this study was to determine the efficacy of exercise training on heart rate variability (HRV) in adult patients with chronic heart failure. A systematic literature review was conducted in electronic databases. The considered studies were randomised clinical trials, quasi-experimental studies with non-randomised control group, quasi-experimental studies with analysis of pre- and post- intervention, and crossover studies with randomly assigned training and non-training periods. The standardised mean differences were calculated between pre- and post-intervention in both the control and experimental group. Within-subject analysis of the control group showed no statistical significance in the standardised mean differences of HRV. In the experimental group, the standardised mean differences were positive for the root mean square of successive difference (+0.468±0.215; P=.032), high frequency band (HF) (0.934±0.256; P < .001) and low frequency band (LF) (< 0.415±0.096; P=.001). Moreover, the standardised mean difference was negative for LF/HF (-0.747±0.369, P=<.044). On the other hand, only 3 studies entered the comparative meta-analysis. The effect of exercise training was favourable for the experimental group in LF/HF (-2.21±95% CI: -3.83 to -0.60), HF, and LF. The exercise training was effective in increasing HRV and restoring the autonomic balance in patients with heart failure. Copyright © 2016 Instituto Nacional de Cardiología Ignacio Chávez. Publicado por Masson Doyma México S.A. All rights reserved.

  20. Clinic and ambulatory heart rates in patients with ischaemic heart disease and/or chronic heart failure taking rate-limiting medications: are they interchangeable?

    Science.gov (United States)

    Javed, Omar; Koo, Kenneth; El-Omar, Omar; Allen, Stuart; Squires, Alexander; El-Omar, Magdi

    2015-01-01

    The prognostic benefit from heart rate (HR) reduction in patients with ischaemic heart disease (IHD) and/or chronic heart failure (CHF) is now firmly established. Most decisions regarding initiation and/or dose adjustment of HR-limiting medications in such patients are based on clinic HR. Yet, this is a highly variable parameter that may not necessarily reflect HR control over the 24 h period. To examine the level of agreement between mean clinic and mean ambulatory HRs in patients with IHD and/or CHF taking rate-limiting medications. Prospective, observational study. Fifty patients with IHD and/or CHF who attended cardiology outpatient clinics at the Manchester Heart Centre and underwent same-day 24 h continuous ECG recording between March and October 2013 were included in the study. Mean clinic HR was compared with mean 24 h, daytime and night-time HRs. Limits-of-agreement plots were constructed to examine the relationship between the two HR measures in more detail. The mean clinic HR was numerically similar to the mean HRs of all ambulatory time periods examined. However, on Bland-Altman plots, the limits of agreement between clinic and ambulatory HR means were quite wide, with the mean clinic HR ranging between 10.93 and 13.58 bpm below and 8.4 and 18.15 bpm above the mean ambulatory HR. Although numerically similar, the means of clinic and ambulatory HRs in patients with IHD and/or CHF display wide limits of agreement. As such, the two measures cannot be regarded as interchangeable. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  1. Post-exercise heart-rate recovery correlates to resting heart-rate variability in healthy men.

    Science.gov (United States)

    Molina, Guilherme Eckhardt; Fontana, Keila Elizabeth; Porto, Luiz Guilherme Grossi; Junqueira, Luiz Fernando

    2016-12-01

    The relationship between post-exercise heart-rate recovery (HRR) and resting cardiac autonomic modulation is an incompletely explored issue. To correlate HRR with resting supine and orthostatic autonomic status. HRR at the 1st, 3th, and 5th min following maximal treadmill exercise were correlated with 5-min time-domain (CV, pNN50 and rMSSD) and frequency-domain (TP, LF, HF, LFn, HFn, and LF/HF ratio) indices of heart-rate variability (HRV) in both supine and standing positions in 31 healthy physically active non-athletes men. Statistical analysis employed non-parametric tests with two-tailed p value set at 5 %. Absolute HRR and Δ %HRR at each post-exercise time did not correlated with HRV in supine position, as well as at 1st min in standing position. At the 3rd min and 5th min, these measures negatively correlated with pNN50, rMSSD, TP, and HF indices, and only in the 5th min, they showed negative correlation with HFn and positive correlation with LF, LFn, and LF/HF ratio in the standing position. Coefficient of HRR (CHRR) at the 1st min negatively correlated with pNN50 and rMSSD and at 3rd and 5th min showed positive correlation with LFn and LF/HF ratio in supine position. With HRV indices in standing position CHRR from the 1st to 5th min showed the same respective negative and positive correlations as the other measures. HRR from the 1st to 5th min post-exercise negatively correlated with parasympathetic modulation in resting orthostatic, but showed no correlation in supine position. At the 3rd and 5th min, a positive correlation with combined sympathetic-parasympathetic modulation in both positions was observed.

  2. The Effect of Valsartan on Heart Rate Variability and Heart Rate Recovery in Patients with Mild to Moderate Mitral Stenosis

    Directory of Open Access Journals (Sweden)

    Ali Metin Esen

    2010-04-01

    Full Text Available Summary: Atrial fibrillation (AF is known to be one of the most important complications of mitral stenosis (MS. It has been reported that autonomic nervous system (ANS had an effect on AF development, heart rate variability (HRV and heart rate recovery (HRR were under the control of ANS, and their disorders were present in MS. We studied the effect of Valsartan on HRV and HRT, and thus its effect on ANS. Methods: Eleven patients (39±8 years, 10 females with mild to moderate MS were included in the study. Sixteen volunteers (38±8 years, 14 females matched for age and sex were selected for control group. All subjects underwent transthoracic echocardiography (TTE, symptom-limited treadmill test and 24 hour Holter monitorization.The patients were administered 160 mg of Valsartan daily for 14 weeks. TTE, treadmill test and Holter monitorization were repeated at the end of treatment period. In Holter monitorization, the time and frequency domain analysis of HRV and in exercise test, HRR at first and third minutes (HRR1 and HRR3 were examined. Results: Before Valsartan treatment, no significant difference was found in HRR and HRV parameters between the two groups. Systolic and diastolic blood pressure, and also HRR1values were significantly decreased after treatment of Valsartan (117±6 vs. 107±4 mmHg p<0.002, 76±6 vs. 69±9 mmHg p<0.044, 44±14 vs. 33±12 p< 0.014, respectively, while the exercise time was significantly increased (786±114 vs. 846±95 sn p< 0.044. In Holter analysis neither time nor frequency domain of HRV parameters showed a meaningful change. Conclusion: In moderate MS, treatment with Valsartan improved the effort capacity, while autonomic function parameters have been defined on the base of HRV and HRR were not significantly different.

  3. Autonomic imbalance induced breakdown of long-range dependence in healthy heart rate.

    Science.gov (United States)

    Aoyagi, N; Struzik, Z R; Kiyono, K; Yamamoto, Y

    2007-01-01

    The investigation of the relation between the long-range correlation property of heart rate and autonomic balance. An investigation of the fractal scaling properties of heart rate variability was carried out by using detrended fluctuation analysis (DFA). Eleven healthy subjects were examined for two consecutive days, which included usual daily activity, strenuous prolonged experimental exercise, and sleep. We also considered two patient groups with autonomic dysfunction characterized by selective sympathetic and parasympathetic dominance. Robust long-range dependence in heart rate is observed only in the state of usual daily activity, characterized by normal heart rate typical of balanced autonomic sympathetic and parasympathetic regulation. This confirms the previously postulated behavioral independence of heart rate regulation, but reveals that the occurrence of 1/f, long-range dependence is restricted to only the state of autonomic balance. Both the sympathetic dominant high heart rate state, realized during strenuous experimental exercise, and the parasympathetic dominant low heart rate state, prevalent in (deep) sleep, are characterized by uncorrelated, near white-noise-like scaling, lacking long-range dependence. Remarkably, the breakdown of the long-range correlations observed in healthy heart rate in the states of sympathetic and parasympathetic dominance is in stark contrast to the increased correlations which have previously been observed in neurogenic parasympathetic and sympathetic dominance in patients suffering from primary autonomic failure and congestive heart failure, respectively. Our findings further reveal the diagnostic capabilities of heart rate dynamics, by differentiating physiological healthy states from pathology.

  4. Reduced Dietary Sodium Intake Increases Heart Rate. A Meta-Analysis of 63 Randomized Controlled Trials Including 72 Study Populations

    National Research Council Canada - National Science Library

    Graudal, Niels A; Hubeck-Graudal, Thorbjørn; Jürgens, Gesche

    2016-01-01

    .... As heart rate is independently associated with the development of heart failure and increased risk of premature death a potential increase in heart rate could be a harmful side-effect of sodium reduction...

  5. The Performance of Short-Term Heart Rate Variability in the Detection of Congestive Heart Failure.

    Science.gov (United States)

    Lucena, Fausto; Barros, Allan Kardec; Ohnishi, Noboru

    2016-01-01

    Congestive heart failure (CHF) is a cardiac disease associated with the decreasing capacity of the cardiac output. It has been shown that the CHF is the main cause of the cardiac death around the world. Some works proposed to discriminate CHF subjects from healthy subjects using either electrocardiogram (ECG) or heart rate variability (HRV) from long-term recordings. In this work, we propose an alternative framework to discriminate CHF from healthy subjects by using HRV short-term intervals based on 256 RR continuous samples. Our framework uses a matching pursuit algorithm based on Gabor functions. From the selected Gabor functions, we derived a set of features that are inputted into a hybrid framework which uses a genetic algorithm and k-nearest neighbour classifier to select a subset of features that has the best classification performance. The performance of the framework is analyzed using both Fantasia and CHF database from Physionet archives which are, respectively, composed of 40 healthy volunteers and 29 subjects. From a set of nonstandard 16 features, the proposed framework reaches an overall accuracy of 100% with five features. Our results suggest that the application of hybrid frameworks whose classifier algorithms are based on genetic algorithms has outperformed well-known classifier methods.

  6. The Performance of Short-Term Heart Rate Variability in the Detection of Congestive Heart Failure

    Directory of Open Access Journals (Sweden)

    Fausto Lucena

    2016-01-01

    Full Text Available Congestive heart failure (CHF is a cardiac disease associated with the decreasing capacity of the cardiac output. It has been shown that the CHF is the main cause of the cardiac death around the world. Some works proposed to discriminate CHF subjects from healthy subjects using either electrocardiogram (ECG or heart rate variability (HRV from long-term recordings. In this work, we propose an alternative framework to discriminate CHF from healthy subjects by using HRV short-term intervals based on 256 RR continuous samples. Our framework uses a matching pursuit algorithm based on Gabor functions. From the selected Gabor functions, we derived a set of features that are inputted into a hybrid framework which uses a genetic algorithm and k-nearest neighbour classifier to select a subset of features that has the best classification performance. The performance of the framework is analyzed using both Fantasia and CHF database from Physionet archives which are, respectively, composed of 40 healthy volunteers and 29 subjects. From a set of nonstandard 16 features, the proposed framework reaches an overall accuracy of 100% with five features. Our results suggest that the application of hybrid frameworks whose classifier algorithms are based on genetic algorithms has outperformed well-known classifier methods.

  7. [Design of Oxygen Saturation, Heart Rate, Respiration Rate Detection System Based on Smartphone of Android Operating System].

    Science.gov (United States)

    Zhu, Mingshan; Zeng, Bixin

    2015-03-01

    In this paper, we designed an oxygen saturation, heart rate, respiration rate monitoring system based on smartphone of android operating system, physiological signal acquired by MSP430 microcontroller and transmitted by Bluetooth module.

  8. Effect of Aerobic Training on Heart Rate Recovery in Patients with Established Heart Disease; a Systematic Review: e83907

    National Research Council Canada - National Science Library

    Johan A Snoek; Sietske van Berkel; Nico van Meeteren; Frank J G Backx; Hein A M Daanen

    2013-01-01

      Background Although a delayed decrease in heart rate during the first minute after graded exercise has been identified as a powerful predictor of overall mortality in cardiac patients, the potential...

  9. Analysis of heart rate during a tennis training session and its relationship with heart-healthy index

    National Research Council Canada - National Science Library

    Díaz Casasola, César

    2010-01-01

    .... The aims of this research were: first, to assess heart rate obtained during a tennis training, changing the intensity at those stages in which the player is hitting the ball, through various forms of displacement: 1...

  10. Nanoimprinted distributed feedback dye laser sensors for high frame rate refractometric imaging of dissolution and fluid flow

    DEFF Research Database (Denmark)

    Vannahme, Christoph; Sørensen, Kristian Tølbøl; Gade, Carsten

    2015-01-01

    High frame rate refractometric dissolution and fluid flow monitoring in one and two dimensions of space with distributed feedback dye laser sensors is presented. The sensors provide both low detection limits and high spatial resolution. © 2015 OSA.......High frame rate refractometric dissolution and fluid flow monitoring in one and two dimensions of space with distributed feedback dye laser sensors is presented. The sensors provide both low detection limits and high spatial resolution. © 2015 OSA....

  11. Sternal pulse rate variability compared with heart rate variability on healthy subjects.

    Science.gov (United States)

    Chreiteh, Shadi S; Belhage, Bo; Hoppe, Karsten; Branebjerg, Jens; Thomsen, Erik V

    2014-01-01

    The heart rate variability (HRV) is a commonly used method to quantify the sympathetic and the parasympathetic modulation of the heart rate. HRV is mainly conducted on electrocardiograms (ECG). However, the use of photo-plethysmography (PPG) as a marker of the autonomic tone is emerging. In this study we investigated the feasibility of deriving pulse rate variability (PRV) using PPG signals recorded by a reflectance PPG sensor attached to the chest bone (sternum) and comparing it to HRV. The recordings were conducted on 9 healthy subjects being in a relaxed supine position and under forced respiration, where the subjects were asked to breathe following a visual scale with a rate of 27 breaths/min. HRV parameters such as the mean intervals (meanNN), the standard deviation of intervals (SDNN), the root mean square of difference of successive intervals (RMSSD), and the proportion of intervals differing more than 50 ms (pNN50) were calculated from the R peak-to-R peak (R-R) and pulse-to-pulse (P-P) intervals. In the frequency domain the low and high frequency ratio of the power spectral density (LF/HF) was also computed. The Pearson correlation coefficient showed significant correlation for all the parameters (r > 0.95 with p healthy subjects at.

  12. Heart rate modulation in stable coronary artery disease without clinical heart failure: What we have already learned from SIGNIFY?

    Directory of Open Access Journals (Sweden)

    Gian Piero Perna

    2016-12-01

    In conclusion, heart rate is a marker of risk but is not a risk factor and/or a target of therapy in patients with stable coronary artery disease and preserved ventricular systolic function. Standard doses of ivabradine are indicated for treatment of angina as an alternative or in addition to beta-blockers, but should not be administered in association with CYP3A4 inhibitors or heart rate-lowering calcium-channel blockers.

  13. Are smoking and passive smoking related with heart rate variability in male adolescents?

    Science.gov (United States)

    Gondim, Renata Melo; Farah, Breno Quintella; Santos, Carolina da Franca Bandeira Ferreira; Ritti-Dias, Raphael Mendes

    2015-01-01

    To analyze the relation between smoking and passive smoking with heart rate variability parameters in male adolescents. The sample consisted of 1,152 males, aged 14 and 19 years. Data related to smoking and passive smoking were collected using a questionnaire. RR intervals were obtained by a heart rate monitor, on supine position, for 10 minutes. After collecting the RR intervals, time (standard deviation of all RR intervals, root mean square of the squared differences between adjacent normal RR intervals and the percentage of adjacent intervals over 50ms) and frequency domains (low and high frequency and sympathovagal balance) parameters of heart rate variability were obtained. No significant differences between smoker and nonsmoker adolescents were observed in heart rate variability parameters (p>0.05). Similarly, heart rate variability parameters did not show significant difference between exposed and not exposed to passive smoking (p>0.05). Cigarette smoking and passive smoking are not related to heart rate variability in adolescence.

  14. Heart rates of elementary physical education students during the dancing classrooms program.

    Science.gov (United States)

    Nelson, Larry; Evans, Melissa; Guess, Wendy; Morris, Mary; Olson, Terry; Buckwalter, John

    2011-06-01

    We examined how different types of dance activities, along with their duration, influenced heart rate responses among fifth-grade physical education students (N = 96) who participated in the Dancing Classrooms program. Results indicated that the overall Dancing Classrooms program elicits a moderate cardiovascular heart rate response (M = 124.4 bpm), in which 47% of class time was spent above a 60% maximal heart rate threshold. The swing dance in particular (M = 143.4 bpm) stimulated a much higher heart rate level than all other dances in the program, with a mean heart rate change of 52.6 bpm. Girls (127.3 bpm) achieved marginally higher heart rates (p = .059) than boys (121.1 bpm).

  15. Approximate entropy and point correlation dimension of heart rate variability in healthy subjects

    DEFF Research Database (Denmark)

    Storella, R J; Wood, H W; Mills, K M

    1999-01-01

    The contribution of nonlinear dynamics to heart rate variability in healthy humans was examined using surrogate data analysis. Several measures of heart rate variability were used and compared. Heart rates were recorded for three hours and original data sets of 8192 R-R intervals created. For each...... original data set (n = 34), three surrogate data sets were made by shuffling the order of the R-R intervals while retaining their linear correlations. The difference in heart rate variability between the original and surrogate data sets reflects the amount of nonlinear structure in the original data set....... Heart rate variability was analyzed by two different nonlinear methods, point correlation dimension and approximate entropy. Nonlinearity, though under 10 percent, could be detected with both types of heart rate variability measures. More importantly, not only were the correlations between...

  16. Reliability of heart rate mobile apps in young healthy adults: exploratory study and research directions.

    Science.gov (United States)

    Parpinel, Maria; Scherling, Laura; Lazzer, Stefano; Della Mea, Vincenzo

    2017-06-30

    Recently, a number of smartphone apps appeared that allow for heart rate measurements basing on the photoplethysmography principle. In fact, almost every smartphone now has a camera with flash that could be used for that. Some studies appeared on the reliability of some of those apps, with heterogeneous results. The present study aims at adding up evidence in particular during physical activity, by comparing 3 apps on two different platforms (IOs and Android), on a broad range of heart rates. As gold standard, heart rate has been measured with a traditional heart rate monitor. The results suggest that heart rate apps might be used for measuring heart rate for fitness aims for many individuals, but further research is needed to i) analyse influence of smartphone features; ii) identify personal factors hindering measurements, and iii) verify reliability on different measurement sites.

  17. A model of blood pressure, heart rate, and vaso-vagal responses produced by vestibulo-sympathetic activation

    Directory of Open Access Journals (Sweden)

    Theodore eRaphan

    2016-03-01

    Full Text Available Blood Pressure (BP, comprised of recurrent systoles and diastoles, is controlled by central mechanisms to maintain blood flow. Periodic behavior of BP was modeled to study how peak amplitudes and frequencies of the systoles are modulated by vestibular activation. The model was implemented as a relaxation oscillator, driven by a central signal related to Desired BP. Relaxation oscillations were maintained by a second order system comprising two integrators and a threshold element in the feedback loop. The output signal related to BP was generated as a nonlinear function of the derivative of the first state variable, which is a summation of an input related to desired BP, feedback from the states, and an input from the vestibular system into one of one of the feedback loops. This nonlinear function was structured to best simulate the shapes of systoles and diastoles, the relationship between BP and Heart Rate (HR as well as the amplitude modulations of BP and Pulse Pressure. Increases in threshold in one of the feedback loops produced lower frequencies of HR, but generated large pulse pressures to maintain orthostasis, without generating a VasoVagal Response (VVR. Pulse pressures were considerably smaller in the anesthetized rats than during the simulations, but simulated pulse pressures were lowered by including saturation in the feedback loop. Stochastic changes in Threshold maintained the compensatory Baroreflex Sensitivity. Sudden decreases in Desired BP elicited non-compensatory VVRs with smaller pulse pressures, consistent with experimental data. The model suggests that the Vestibular Sympathetic Reflex modulates BP and HR of an oscillating system by manipulating parameters of the baroreflex feedback and the signals that maintain the oscillations. It also shows that a VVR is generated when the vestibular input triggers a marked reduction in Desired BP.

  18. Circadian heart rate variability in patients with primary arterial hypertension.

    Science.gov (United States)

    Kolasińska-Kloch, Władysława; Furgała, Agata; Banach, Tomasz; Laskiewicz, Janusz; Thor, Piotr J

    2002-01-01

    Abnormalities of autonomic nervous system function (ANS) exist in patients with hypertension and have been considered as one of the important factors in developing of essential hypertension. However the information about the effect of antihypertensive treatment (angiotensin-converting enzyme inhibitors--ACEI) on cardiac ANS activity is scarce. The main aim of our study was to evaluate circadian heart rate variability changes in primary hypertension treated with ACE inhibitors. Fourteen patients with essential hypertension with night/day differences of mean blood pressure of more than 10% (dippers) aged 26 to 61 years (mean 52.9 +/- 9.2) and 14 healthy volunteers, 14 healthy volunteers were recruited and matched for age and gender. Ambulatory 24 hour arterial blood pressure measurement using HolCARD (Aspel, Poland) recorder with simultaneous ECG monitoring using the Mediarc-Premier IV Holter Monitoring System (DRG-International) undertaken in both groups of patients. The hypertensive patients were tested before and after one year of the enalapril treatment. The HRV analysis was performed according to a standard Fast Fourier Transformation (FFT). The time and spectral analysis parameters were compared within the examined groups of patients during day and night. The results obtained in the control group showed the great circadian fluctuations in sympathetic and parasympathetic activity. A simultaneous circadian HRV evaluation showed also significant increases in night RMSSD, TP, VLF, LF and HF mean values (p < 0.05) with significantly decreased night LF/HF ratio (p < 0.05) in comparison to the day time recordings. After one year of ACE inhibitors treatment, we noted the following circadian changes: Significant increase of RMSSD, pNN50 (p < 0.05), TP, VLF, LF and HF (p < 0.05) parameters with non-significant increases in LF/HF ratio during night recording. A comparison between daily HRV parameters, before and after 1 year of ACEI treatment, presented significant

  19. A Rate-Compatible Sphere-Packing Analysis of Feedback Coding with Limited Retransmissions

    CERN Document Server

    Williamson, Adam R; Wesel, Richard D

    2012-01-01

    Recent work by Polyanskiy et al. and Chen et al. have excited new interest in using feedback to approach capacity with low latency. Polyanskiy showed that feedback identifying the first symbol at which decoding is successful allows capacity to be approached with surprisingly low latency. This paper uses Chen's rate-compatible sphere-packing (RCSP) analysis to study what happens when symbols must be transmitted in packets, as with a traditional hybrid ARQ system, and limited to relatively few (six or fewer) incremental transmissions. Numerical optimizations find the series of progressively growing cumulative block lengths that enable RCSP to approach capacity with the minimum possible latency. RCSP analysis shows that five incremental transmissions are sufficient to achieve 92% of capacity with an average block length of fewer than 101 symbols on the AWGN channel with SNR of 2.0 dB. The RCSP analysis provides a decoding error trajectory that specifies the decoding error rate for each cumulative block length. T...

  20. Cold-hearted bats: uncoupling of heart rate and metabolism during torpor at subzero temperatures.

    Science.gov (United States)

    Currie, Shannon E; Stawski, Clare; Geiser, Fritz

    2017-11-07

    Many hibernating animals thermoregulate during torpor and defend their body temperature (Tb) below 10°C by an increase in metabolic rate. Above a critical temperature (Tcrit) animals usually thermoconform. We investigated the physiological responses above and below Tcrit for a small tree dwelling bat (Chalinolobus gouldii, ∼14 g) that is often exposed to subzero temperatures during winter. Through simultaneous measurement of heart rate (HR) and oxygen consumption (V̇O2) we show that the relationship between oxygen transport and cardiac function is substantially altered in thermoregulating torpid bats between 1 and -2°C, compared with thermoconforming torpid bats at mild ambient temperatures (Ta 5-20°C). Tcrit for this species was Ta 0.7±0.4°C, with a corresponding Tb of 1.8±1.2°C. Below Tcrit animals began to thermoregulate, indicated by a considerable but disproportionate increase in both HR and V̇O2 The maximum increase in HR was only 4-fold greater than the average thermoconforming minimum, compared to a 46-fold increase in V̇O2 The differential response of HR and V̇O2 to low Ta was reflected in a 15-fold increase in oxygen delivery per heart beat (cardiac oxygen pulse). During torpor at low Ta, thermoregulating bats maintained a relatively slow HR and compensated for increased metabolic demands by significantly increasing stroke volume and tissue oxygen extraction. Our study provides new information on the relationship between metabolism and HR in an unstudied physiological state that may occur frequently in the wild and can be extremely costly for heterothermic animals. © 2017. Published by The Company of Biologists Ltd.

  1. Effect of changing heart rate during treatment of hypertension on incidence of heart failure.

    Science.gov (United States)

    Okin, Peter M; Kjeldsen, Sverre E; Julius, Stevo; Hille, Darcy A; Dahlöf, Björn; Devereux, Richard B

    2012-03-01

    An elevated heart rate (HR) at rest at baseline is associated with an increased risk of incident heart failure (HF) and with greater cardiovascular event rates in patients with chronic HF. However, despite the high attributable risk of hypertension for HF, whether the in-treatment HR predicts incident HF in patients with treated hypertension has not been evaluated. The HR was evaluated on annual electrocardiograms from 9,024 patients with hypertension without HF who were treated with losartan- or atenolol-based regimens. During a mean follow-up of 4.7 ± 1.1 years, HF developed in 285 patients (3.2%). On multivariate Cox analyses adjusted for randomized treatment, the baseline risk factors for HF, baseline and in-treatment blood pressure, QRS duration, and electrocardiographic left ventricular hypertrophy, a greater in-treatment HR predicted a 45% greater adjusted risk of new HF for every 10-beats/min increase in the HR (95% confidence interval [CI] 34% to 57%) or a 159% greater risk of HF in patients with the persistence or development of a HR of ≥84 beats/min (95% CI 88% to 257%). In contrast, with adjustment for the same covariates, the baseline HR as a continuous variable was a significantly less powerful predictor of new HF (hazard ratio 1.15 per 10 beats/min, 95% CI 1.03 to 1.28) and a baseline HR of ≥84 beats/min did not predict new HF (hazard ratio 1.00, 95% CI 0.63 to 1.58). In conclusion, a greater in-treatment HR on the serial electrocardiograms predicts a greater risk of incident HF during antihypertensive treatment, independent of the covariates, in patients with hypertension with electrocardiographic left ventricular hypertrophy. These findings support serial HR assessment to improve the risk stratification of patients with hypertension. Copyright © 2012 Elsevier Inc. All rights reserved.

  2. Heart rate variability in sleep-related migraine without aura.

    Science.gov (United States)

    Vollono, Catello; Gnoni, Valentina; Testani, Elisa; Dittoni, Serena; Losurdo, Anna; Colicchio, Salvatore; Di Blasi, Chiara; Mazza, Salvatore; Farina, Benedetto; Della Marca, Giacomo

    2013-07-15

    This is an observational study aimed to investigate the activity of autonomic nervous system during sleep in patients with sleep-related migraine. Eight consecutive migraineurs without aura were enrolled (6 women and 2 men), aged 30 to 62 years (mean 48.1 ± 9.3 years). Inclusion criteria were: high frequency of attacks (> 5 per month) and occurrence of more than 75% of the attacks during sleep causing an awakening. Patients were compared with a control group of 55 healthy subjects (23 men and 32 women, mean age 54.2 ± 13.0 years), and with a further control group of 8 age- and gender-matched healthy controls. Patient and controls underwent polysomnography and heart rate variability analysis. A significant reduction of the LF/HF ratio during N2 and N3 sleep stages was observed in migraineurs compared with controls. No differences in sleep macrostructure were observed; cyclic alternating pattern (CAP) time and CAP rate were lower in migraineurs than in controls. These findings indicate a peculiar modification of the autonomic balance during sleep in sleep-related migraine. The reduction of LF/HF ratio in NREM sleep was observed in controls, but it was quantitatively much more evident in migraineurs. Changes in LF/HF could be consequent to an autonomic unbalance which could manifest selectively (or alternatively become more evident) during sleep. These findings, together with the reduction in CAP rate, could be an expression of reduced arousability during sleep in patients with sleep-related migraine. The simultaneous involvement of the autonomic, arousal, and pain systems might suggest involvement of the hypothalamic pathways.

  3. Running wavelet archetype aids the determination of heart rate from the video photoplethysmogram during motion.

    Science.gov (United States)

    Addison, Paul S; Foo, David M H; Jacquel, Dominique

    2017-07-01

    The extraction of heart rate from a video-based biosignal during motion using a novel wavelet-based ensemble averaging method is described. Running Wavelet Archetyping (RWA) allows for the enhanced extraction of pulse information from the time-frequency representation, from which a video-based heart rate (HRvid) can be derived. This compares favorably to a reference heart rate derived from a pulse oximeter.

  4. Decomposition of heart rate variability by adaptive filtering for estimation of cardiac vagal tone

    OpenAIRE

    Han, Kedu; Nagel, Joachim H.; Hurwitz, Barry E.; Schneiderman, Neil

    1991-01-01

    Heart rate fluctuations resulting from respiration and other influences upon the cardiovascular system are encoded into the patterns of heart rate variability (HRV). The fluctuations due to respiration are called respiratory sinus arrhythmia (RSA). Since RSA is primarily mediated through the autonomic nervous system (ANS), it is of interest to separate RSA from other influences to assess the underlying ANS function. On the other hand, the RSA may obscure heart rate responses to external manip...

  5. Components of the cannabinoid system in the dorsal periaqueductal gray are related to resting heart rate

    OpenAIRE

    Dean, Caron; Hillard, Cecilia J.; Seagard, Jeanne L.; Hopp, Francis A.; Hogan, Quinn H.

    2016-01-01

    The present study was undertaken to examine whether variations in endocannabinoid signaling in the dorsal periaqueductal gray (dPAG) are associated with baseline autonomic nerve activity, heart rate, and blood pressure. Blood pressure was recorded telemetrically in rats, and heart rate and power spectral analysis of heart rate variability were determined. Natural variations from animal to animal provided a range of baseline values for analysis. Transcript levels of endocannabinoid signaling c...

  6. Analysis of feedbacks between nucleation rate, survival probability and cloud condensation nuclei formation

    Science.gov (United States)

    Westervelt, D. M.; Pierce, J. R.; Adams, P. J.

    2014-06-01

    Aerosol nucleation is an important source of particle number in the atmosphere. However, in order to become cloud condensation nuclei (CCN), freshly nucleated particles must undergo significant condensational growth while avoiding coagulational scavenging. In an effort to quantify the contribution of nucleation to CCN, this work uses the GEOS-Chem-TOMAS global aerosol model to calculate changes in CCN concentrations against a broad range of nucleation rates and mechanisms. We then quantify the factors that control CCN formation from nucleation, including daily nucleation rates, growth rates, coagulation sinks, condensation sinks, survival probabilities, and CCN formation rates, in order to examine feedbacks that may limit growth of nucleated particles to CCN. Nucleation rate parameterizations tested in GEOS-Chem-TOMAS include ternary nucleation (with multiple tuning factors), activation nucleation (with two pre-factors), binary nucleation, and ion-mediated nucleation. We find that nucleation makes a significant contribution to boundary layer CCN(0.2%), but this contribution is only modestly sensitive to the choice of nucleation scheme, ranging from 49 to 78% increase in concentrations over a control simulation with no nucleation. Moreover, a two order-of-magnitude increase in the globally averaged nucleation rate (via changes to tuning factors) results in small changes (less than 10%) to global CCN(0.2%) concentrations. To explain this, we present a simple theory showing that survival probability has an exponentially decreasing dependence on the square of the condensation sink. This functional form stems from a negative correlation between condensation sink and growth rate and a positive correlation between condensation sink and coagulational scavenging. Conceptually, with a fixed condensable vapor budget (sulfuric acid and organics), any increase in CCN concentrations due to higher nucleation rates necessarily entails an increased aerosol surface area in the

  7. Heart rate variability and heart rate turbulence in patients with type 2 diabetes mellitus with versus without cardiac autonomic neuropathy.

    Science.gov (United States)

    Balcioğlu, Serhat; Arslan, Uğur; Türkoğlu, Sedat; Ozdemir, Murat; Cengel, Atiye

    2007-09-01

    Cardiac autonomic neuropathy (CAN) is an important complication of diabetes mellitus (DM) and confers an increased cardiovascular risk. The aim of this study was to disclose the place of heart rate (HR) variability and HR turbulence for the detection of CAN in patients with type 2 DM and no obvious heart disease. Ninety patients who were /=2 years were studied. CAN was diagnosed with a battery of cardiovascular reflex tests and the degree of neuropathic involvement was graded by the Ewing score. Time-domain HR variability and HR turbulence parameters were assessed on 24-hour digital Holter recordings. Thirty-five patients were found to have CAN. The clinical characteristics of patients with and without CAN were similar, except that the mean duration of DM and the number of patients using insulin were significantly increased in the group with CAN. All time-domain HR variability parameters were significantly lower in the group with CAN. Of the 2 HR turbulence parameters studied, turbulence onset was similar but turbulence slope was significantly lower in the group with CAN. The Ewing score significantly correlated negatively with all HR variability parameters and turbulence slope, and among all, turbulence slope was the most strongly correlated (r = -0.617, p <0.01). Receiver-operating characteristics analysis revealed a sensitivity of 97% and a specificity of 71% at a turbulence slope cut-off value of 3.32 for the detection of CAN. In conclusion, time-domain HR variability and HR turbulence parameters, except turbulence, onset were found to be significantly depressed in patients with type 2 DM and CAN. Decreases in all these parameters were found to correlate significantly with degree of neuropathic involvement. The most strongly correlated parameter, turbulence slope, was found to be highly sensitive and specific for the detection of CAN at a cut-off value of 3.32.

  8. High frame rate multi-resonance imaging refractometry with distributed feedback dye laser sensor

    DEFF Research Database (Denmark)

    Vannahme, Christoph; Dufva, Martin; Kristensen, Anders

    2015-01-01

    High frame rate and highly sensitive imaging of refractive index changes on a surface is very promising for studying the dynamics of dissolution, mixing and biological processes without the need for labeling. Here, a highly sensitive distributed feedback (DFB) dye laser sensor for high frame rate...... by analyzing laser light from all areas in parallel with an imaging spectrometer. With this multi-resonance imaging refractometry method, the spatial position in one direction is identified from the horizontal, i.e., spectral position of the multiple laser lines which is obtained from the spectrometer charged...... coupled device (CCD) array. The orthogonal spatial position is obtained from the vertical spatial position on the spectrometer CCD array as in established spatially resolved spectroscopy. Here, the imaging technique is demonstrated by monitoring the motion of small sucrose molecules upon dissolution...

  9. Relationship between heart rate and quiescent interval of the cardiac cycle in children using MRI.

    Science.gov (United States)

    Zhang, Wei; Bogale, Saivivek; Golriz, Farahnaz; Krishnamurthy, Rajesh

    2017-11-01

    Imaging the heart in children comes with the challenge of constant cardiac motion. A prospective electrocardiography-triggered CT scan allows for scanning during a predetermined phase of the cardiac cycle with least motion. This technique requires knowing the optimal quiescent intervals of cardiac cycles in a pediatric population. To evaluate high-temporal-resolution cine MRI of the heart in children to determine the relationship of heart rate to the optimal quiescent interval within the cardiac cycle. We included a total of 225 consecutive patients ages 0-18 years who had high-temporal-resolution cine steady-state free-precession sequence performed as part of a magnetic resonance imaging (MRI) or magnetic resonance angiography study of the heart. We determined the location and duration of the quiescent interval in systole and diastole for heart rates ranging 40-178 beats per minute (bpm). We performed the Wilcoxon signed rank test to compare the duration of quiescent interval in systole and diastole for each heart rate group. The duration of the quiescent interval at heart rates bpm and >90 bpm was significantly longer in diastole and systole, respectively (Pbpm [P=.02]). For heart rates 80-89 bpm, diastolic interval was longer than systolic interval, but the difference was not statistically significant (P=.06). We created a chart depicting optimal quiescent intervals across a range of heart rates that could be applied for prospective electrocardiography-triggered CT imaging of the heart. The optimal quiescent interval at heart rates bpm is in diastole and at heart rates ≥90 bpm is in systole. The period of quiescence at heart rates 80-89 bpm is uniformly short in systole and diastole.

  10. Gender- and age-related differences in heart rate dynamics: are women more complex than men?

    Science.gov (United States)

    Ryan, S. M.; Goldberger, A. L.; Pincus, S. M.; Mietus, J.; Lipsitz, L. A.

    1994-01-01

    OBJECTIVES. This study aimed to quantify the complex dynamics of beat-to-beat sinus rhythm heart rate fluctuations and to determine their differences as a function of gender and age. BACKGROUND. Recently, measures of heart rate variability and the nonlinear "complexity" of heart rate dynamics have been used as indicators of cardiovascular health. Because women have lower cardiovascular risk and greater longevity than men, we postulated that there are important gender-related differences in beat-to-beat heart rate dynamics. METHODS. We analyzed heart rate dynamics during 8-min segments of continuous electrocardiographic recording in healthy young (20 to 39 years old), middle-aged (40 to 64 years old) and elderly (65 to 90 years old) men (n = 40) and women (n = 27) while they performed spontaneous and metronomic (15 breaths/min) breathing. Relatively high (0.15 to 0.40 Hz) and low (0.01 to 0.15 Hz) frequency components of heart rate variability were computed using spectral analysis. The overall "complexity" of each heart rate time series was quantified by its approximate entropy, a measure of regularity derived from nonlinear dynamics ("chaos" theory). RESULTS. Mean heart rate did not differ between the age groups or genders. High frequency heart rate power and the high/low frequency power ratio decreased with age in both men and women (p cardiovascular disease risk and greater longevity in women requires further study.

  11. Episodic arterial oxygen desaturation and heart rate variations following major abdominal surgery

    DEFF Research Database (Denmark)

    Rosenberg, J; Dirkes, W E; Kehlet, H

    1989-01-01

    In 20 patients undergoing elective major abdominal surgery, heart rate and arterial oxygen saturation were monitored continuously during the night 2 days before operation and during the first and second nights after operation (23:00 to 07:30). Mean heart rate increased by 16 beat min-1 (P less than...... arrhythmias on the morning of the third day after operation. In another patient the episodes of desaturation correlated with increases in heart rate. There was no correlation between administration of opioids and heart rate and saturation disturbances. The mechanism and clinical relevance of episodic...

  12. The role of preparatory heart rate deceleration on balance beam performance.

    Science.gov (United States)

    Cottyn, Jorge; de Clercq, Dirk; Crombez, Geert; Lenoir, Matthieu

    2008-04-01

    Preparatory heart rate deceleration occurs in tasks with an external focus of attention and is often assumed to facilitate balance performance. However, its effects upon sport-related complex balance movements have not been studied. Heart rate patterns during the preparation period of an acrobatic element (flic-flac) on the balance beam were studied in 14 female gymnasts (M age 13.2 years). A significant heart rate deceleration was found in attempts with a fall in the consecutive acrobatic element, but not in attempts without a fall. These data suggest that preparatory heart rate deceleration may be detrimental to the performance of complex movements on the balance beam.

  13. Variation in heart rate during submaximal exercise: implications for monitoring training.

    Science.gov (United States)

    Lamberts, Robert P; Lemmink, Koen A P M; Durandt, Justin J; Lambert, Michael I

    2004-08-01

    A change in heart rate at a controlled submaximal exercise intensity is used as a marker of training status. However, the standard error of measurement has not been studied systematically, and therefore a change in heart rate, which can be considered relevant, has not been determined. Forty-four subjects (26.5 +/- 5.4 years; mean +/- standard deviation) participated in a submaximal running test at the same time of day for 5 consecutive days. Heart rates were determined during each of the 4 exercise intensities (2 minutes each) of increasing intensity and during the 1-minute recovery period after each stage. The repeatability of the heart rate on a day-to-day basis during the stages and recovery periods were high (intraclass correlation coefficient: 95% confidence interval R = 0.94- 0.99). The lowest variation in heart rate occurred in the fourth stage ( approximately 90% maximum heart rate) with heart rate varying 5 +/- 2 b.min(-1) (95% confidence interval for coefficient of variation = 1.1-1.4%). In conclusion, the standard error of measurement of submaximal heart rate is 1.1-1.4%. This magnitude of measurement error needs to be considered when heart rate is used as a marker of training status.

  14. THE ANALYSIS OF HEART RATE VARIABILITY IN ELITE ATHLETES DURING NON STATION NARY PROCESSES

    Directory of Open Access Journals (Sweden)

    G. V. Korobeynikov

    2016-06-01

    Full Text Available The heart rate variability during non stationary processes in athletes was studied. The 29 elite athletes were examined. The parameters of scattergram for analysis of non stationnary processes of heart rate regulation were used. The results are shows about of tendency for decrease of periodic and non periodic variations of cardiac intervals depending from characters of reaction of heart rate. The obtained result showed the aging increasing of tension of autonomic regulation of heart rate of athletes as fatigue or non adequate performance.

  15. Rate-Optimal Multiuser Scheduling with Reduced Feedback Load and Analysis of Delay Effects

    Directory of Open Access Journals (Sweden)

    Alouini Mohamed-Slim

    2006-01-01

    Full Text Available We propose a feedback algorithm for wireless networks that always collects feedback from the user with the best channel conditions and has a significant reduction in feedback load compared to full feedback. The algorithm is based on a carrier-to-noise threshold, and closed-form expressions for the feedback load as well as the threshold value that minimizes the feedback load have been found. We analyze two delay scenarios. The first scenario is where the scheduling decision is based on outdated channel estimates, and the second scenario is where both the scheduling decision and the adaptive modulation are based on outdated channel estimates.

  16. G protein-coupled estrogen receptor regulates embryonic heart rate in zebrafish.

    Science.gov (United States)

    Romano, Shannon N; Edwards, Hailey E; Souder, Jaclyn Paige; Ryan, Kevin J; Cui, Xiangqin; Gorelick, Daniel A

    2017-10-24

    Estrogens act by binding to estrogen receptors alpha and beta (ERα, ERβ), ligand-dependent transcription factors that play crucial roles in sex differentiation, tumor growth and cardiovascular physiology. Estrogens also activate the G protein-coupled estrogen receptor (GPER), however the function of GPER in vivo is less well understood. Here we find that GPER is required for normal heart rate in zebrafish embryos. Acute exposure to estrogens increased heart rate in wildtype and in ERα and ERβ mutant embryos but not in GPER mutants. GPER mutant embryos exhibited reduced basal heart rate, while heart rate was normal in ERα and ERβ mutants. We detected gper transcript in discrete regions of the brain and pituitary but not in the heart, suggesting that GPER acts centrally to regulate heart rate. In the pituitary, we observed gper expression in cells that regulate levels of thyroid hormone triiodothyronine (T3), a hormone known to increase heart rate. Compared to wild type, GPER mutants had reduced levels of T3 and estrogens, suggesting pituitary abnormalities. Exposure to exogenous T3, but not estradiol, rescued the reduced heart rate phenotype in gper mutant embryos, demonstrating that T3 acts downstream of GPER to regulate heart rate. Using genetic and mass spectrometry approaches, we find that GPER regulates maternal estrogen levels, which are required for normal embryonic heart rate. Our results demonstrate that estradiol plays a previously unappreciated role in the acute modulation of heart rate during zebrafish embryonic development and suggest that GPER regulates embryonic heart rate by altering maternal estrogen levels and embryonic T3 levels.

  17. Nonlinear Control of Heart Rate Variability in Human Infants

    Science.gov (United States)

    Sugihara, George; Allan, Walter; Sobel, Daniel; Allan, Kenneth D.

    1996-03-01

    Nonlinear analyses of infant heart rhythms reveal a marked rise in the complexity of the electrocardiogram with maturation. We find that normal mature infants (gestation >= 35 weeks) have complex and distinctly nonlinear heart rhythms (consistent with recent reports for healthy adults) but that such nonlinearity is lacking in preterm infants (gestation physiological states.

  18. Heart Rate Variability Analysis in Patients with Allergic Rhinitis

    Directory of Open Access Journals (Sweden)

    Ming-Ying Lan

    2013-01-01

    Full Text Available Background. Very few studies investigate the role of the autonomic nervous system in allergic rhinitis. In this study, we evaluated the autonomic nervous system in allergic rhinitis patients using heart rate variability (HRV analysis. Methods. Eleven patients with allergic rhinitis and 13 healthy controls, aged between 19 and 40 years old, were enrolled in the study. Diagnosis of allergic rhinitis was based on clinical history, symptoms, and positive Phadiatop test. Electrocardiographic recordings on the sitting and supine positions were obtained for HRV analysis. Results. In the supine position, there were no significant statistical differences in very-low-frequency power (VLF, ≤0.04 Hz, low-frequency power (LF, 0.04–0.15 Hz, high-frequency power (HF, 0.15–0.40 Hz, and the ratio of LF to HF (LF/HF between the patient and control groups. The mean RR intervals significantly increased, while LF% and LF/HF significantly decreased in the patient group in the sitting position. Moreover, mean RR intervals, LF, and LF/HF, which were significantly different between the two positions in the control group, did not show a significant change with the posture change in the patient group. Conclusion. These suggest that patients with allergic rhinitis may have poor sympathetic modulation in the sitting position. Autonomic dysfunction may therefore play a role in the pathophysiology of allergic rhinitis.

  19. Multiscale analysis of heart rate variability in nonstationary environments

    Directory of Open Access Journals (Sweden)

    Jianbo eGao

    2013-05-01

    Full Text Available Heart rate variability (HRV is highly nonstationary, even if no perturbing influences can be identified during the recording of the data. The nonstationarity becomes more profound when HRV data are measured in intrinsically nonstationary environments, such as social stress. In general, HRV data measured in such situations are more difficult to analyze than those measured in constant environments. In this paper, we analyze HRV data measured during a social stress test using two multiscale approaches, the adaptive fractal analysis (AFA and scale-dependent Lyapunov exponent (SDLE, for the purpose of uncovering differences in HRV between chronic fatigue syndrome (CFS patients and their matched-controls. CFS is a debilitating, heterogeneous illness with no known biomarker. HRV has shown some promise recently as a non-invasive measure of subtle physiological disturbances and trauma that are otherwise difficult to assess. If the HRV in persons with CFS are significantly different from their healthy controls, then certain cardiac irregularities may constitute good candidate biomarkers for CFS. Our multiscale analyses show that there are notable differences in HRV between CFS and their matched controls before a social stress test, but these differences seem to diminish during the test. These analyses illustrate that the two employed multiscale approaches could be useful for the analysis of HRV measured in various environments, both stationary and nonstationary.

  20. Heart-rate monitoring by air pressure and causal analysis

    Science.gov (United States)

    Tsuchiya, Naoki; Nakajima, Hiroshi; Hata, Yutaka

    2011-06-01

    Among lots of vital signals, heart-rate (HR) is an important index for diagnose human's health condition. For instance, HR provides an early stage of cardiac disease, autonomic nerve behavior, and so forth. However, currently, HR is measured only in medical checkups and clinical diagnosis during the rested state by using electrocardiograph (ECG). Thus, some serious cardiac events in daily life could be lost. Therefore, a continuous HR monitoring during 24 hours is desired. Considering the use in daily life, the monitoring should be noninvasive and low intrusive. Thus, in this paper, an HR monitoring in sleep by using air pressure sensors is proposed. The HR monitoring is realized by employing the causal analysis among air pressure and HR. The causality is described by employing fuzzy logic. According to the experiment on 7 males at age 22-25 (23 on average), the correlation coefficient against ECG is 0.73-0.97 (0.85 on average). In addition, the cause-effect structure for HR monitoring is arranged by employing causal decomposition, and the arranged causality is applied to HR monitoring in a setting posture. According to the additional experiment on 6 males, the correlation coefficient is 0.66-0.86 (0.76 on average). Therefore, the proposed method is suggested to have enough accuracy and robustness for some daily use cases.

  1. Heart rate variability is reduced during acute uncomplicated diverticulitis.

    Science.gov (United States)

    Huang, Chenxi; Alamili, Mahdi; Rosenberg, Jacob; Gögenur, Ismail

    2016-04-01

    The aim of the present study was to report the trajectory of heart rate variability (HRV) indices during a low-grade acute inflammation and their associations to biomarkers for infection. Twelve patients with uncomplicated acute diverticulitis completed this observational study, which composed of 3 sessions of continuous HRV recording from 9 PM to 8 AM during ongoing diverticulitis and at complete remission (baseline). The blood samples were collected at each study session measuring C-reactive protein (CRP) and leukocytes. This study showed that the trajectories of the HRV indices were decreased both in time and frequency domains during acute diverticulitis compared to baseline. In particular, the indices reflecting the balance of sympathetic and parasympathetic activities were affected: standard deviation of normal-to-normal beats (P = .003), low-frequency power (P diverticulitis suggesting inflammatory involvement in the observed HRV alterations. We found substantial HRV depression in relation to acute uncomplicated diverticulitis, and this was associated with the elevated CRP levels. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Heart rate recovery predicts memory performance in older adults.

    Science.gov (United States)

    Pearman, Ann; Lachman, Margie E

    2010-06-01

    The current study examined cardiovascular reactivity and recovery during memory testing in a sample of 28 younger and 28 older adults. Heart rate (HR) levels were measured before, during, and after a memory test (word list recall). Contrary to prediction, older adults did not have a blunted cardiovascular response to memory tasks compared to younger adults. Word list recall performance was predicted by both Age and an Age x HR recovery interaction. As expected, younger adults performed better on the word list task than older adults. In addition, older adults with better posttest HR recovery performed significantly better than older adults with poor posttest HR recovery, whereas HR recovery differences in younger adults were inconsequential. These relationships were not affected by subjective appraisals of anxiety and task difficulty. Overall, cardiac dysregulation, seen here as low HR recovery, represents an important, potentially modifiable, factor in memory performance in older adults. In addition to being beneficial to overall health, interventions designed to help older adults regulate their HR responses may help offset certain memory declines.

  3. Heart Rate Recovery after Cognitive Challenge is Preserved with Age

    Science.gov (United States)

    Shcheslavskaya, Olga V.; Burg, Matthew M.; McKinley, Paula S.; Schwartz, Joseph E.; Gerin, William; Ryff, Carol D.; Weinstein, Maxine; Seeman, Teresa E.; Sloan, Richard P.

    2010-01-01

    Objectives To investigate the effect of age on heart rate recovery (HRR) from cognitive challenge. Background Aging is an independent risk factor for the development of cardiovascular disease. HRR from exercise is an established predictor of cardiac morbidity and mortality, and evidence suggests that HRR from cognitive challenge is predictive of cardiac morbidity as well. Aging is associated with delayed HRR from exercise stress, but little is known about the effect of aging on HRR from psychological stress. We tested the hypothesis that age would be related to delayed HRR from psychological stress. Methods HRR following exposure to cognitive challenge (mental arithmetic and Stroop) was investigated in a sample of 436 participants aged 35–84 in MIDUS II, a national study of health and well-being. HRR was measured as (1) the amount of change from the stress level; (2) time to recover; and (3) the area under the curve (AUC). The analyses were controlled for medical comorbidities and medications that influence HR, such as BMI, smoking, sex, menopausal status, and amount of physical activity/exercise. Results There was no effect for age on HRR as evaluated by all three recovery assessment methods. Conclusions Contrary to expectation and in contrast to findings concerning HRR from exercise, HRR from cognitive challenge was preserved with age. These findings require further inquiry into differential mechanism(s) underlying HRR from psychological vs. exercise stress, including any role for improved emotion regulation with greater age. PMID:20028831

  4. Heart rate variability: a tool to explore the sleeping brain?

    Directory of Open Access Journals (Sweden)

    Florian eChouchou

    2014-12-01

    Full Text Available Sleep is divided into two main sleep stages: 1 non-rapid eye movement sleep (non-REMS, characterized among others by reduced global brain activity; and 2 rapid eye movement sleep (REMS, characterized by global brain activity similar to that of wakefulness. Results of heart rate variability (HRV analysis, which is widely used to explore autonomic modulation, have revealed higher parasympathetic tone during normal non-REMS and a shift toward sympathetic predominance during normal REMS. Moreover, HRV analysis combined with brain imaging has identified close connectivity between autonomic cardiac modulation and activity in brain areas such as the amygdala and insular cortex during REMS, but no connectivity between brain and cardiac activity during non-REMS. There is also some evidence for an association between HRV and dream intensity and emotionality. Following some technical considerations, this review addresses how brain activity during sleep contributes to changes in autonomic cardiac activity, organized into three parts: 1 the knowledge on autonomic cardiac control, 2 differences in brain and autonomic activity between non-REMS and REMS, and 3 the potential of HRV analysis to explore the sleeping brain, and the implications for psychiatric disorders.

  5. Extraction of Heart Rate Variability from Smartphone Photoplethysmograms

    Directory of Open Access Journals (Sweden)

    Rong-Chao Peng

    2015-01-01

    Full Text Available Heart rate variability (HRV is a useful clinical tool for autonomic function assessment and cardiovascular diseases diagnosis. It is traditionally calculated from a dedicated medical electrocardiograph (ECG. In this paper, we demonstrate that HRV can also be extracted from photoplethysmograms (PPG obtained by the camera of a smartphone. Sixteen HRV parameters, including time-domain, frequency-domain, and nonlinear parameters, were calculated from PPG captured by a smartphone for 30 healthy subjects and were compared with those derived from ECG. The statistical results showed that 14 parameters (AVNN, SDNN, CV, RMSSD, SDSD, TP, VLF, LF, HF, LF/HF, nLF, nHF, SD1, and SD2 from PPG were highly correlated (r>0.7, P<0.001 with those from ECG, and 7 parameters (AVNN, TP, VLF, LF, HF, nLF, and nHF from PPG were in good agreement with those from ECG within the acceptable limits. In addition, five different algorithms to detect the characteristic points of PPG wave were also investigated: peak point (PP, valley point (VP, maximum first derivative (M1D, maximum second derivative (M2D, and tangent intersection (TI. The results showed that M2D and TI algorithms had the best performance. These results suggest that the smartphone might be used for HRV measurement.

  6. Long-term measurement of heart rate in chicken eggs.

    Science.gov (United States)

    Akiyama, R; Matsuhisa, A; Pearson, J T; Tazawa, H

    1999-12-01

    Taking advantage of acoustocardiogram (ACG), we measured the heart rate (HR) of chick embryos continuously from day 12 until hatching and then investigated the development of HR irregularities (HRI), HR variability (HRV), and the existence of a circadian rhythm in mean HR (MHR). HRI comprised transient bradycardia and tachycardia, which first developed on day 14 and 16 in most embryos, respectively. Transient bradycardia increased in frequency and magnitude with embryonic development and occurred over periods of up to 30 min in some embryos. MHR was maximal on around days 14-15 and thereafter decreased to about 250-260 bpm on days 16-18. Baseline HRV, which is an oscillation of the MHR baseline, occurred as HR decreased from days 15-16 and became predominant on days 17-18. The magnitude of the baseline oscillations reached up to 50 bpm in some embryos and the period ranged between about 40-90 min (ultradian rhythm). A circadian rhythm of MHR was not found in late chick embryos. On days 18-19, embryonic activities were augmented and then breathing movements began to occur, disturbing ACG signals and thus making it difficult to measure the HR. Instead, the development of breathing activities was recorded. Breathing frequency was irregular at first and then increased to a maximum of about 1.5 Hz prior to hatching.

  7. Heart Rate Variability Discriminates Competitive Levels in Professional Soccer Players.

    Science.gov (United States)

    Proietti, Riccardo; di Fronso, Selenia; Pereira, Lucas A; Bortoli, Laura; Robazza, Claudio; Nakamura, Fabio Y; Bertollo, Maurizio

    2017-06-01

    Heart rate variability (HRV) has been increasingly used to monitor team sports athletes. Besides the traditional time domain indices (i.e., the SD of successive RR intervals [SDNN] and the root mean square difference of successive normal RR intervals [RMSSD]), recently the use of the stress score (SS), which is an inverse function of the SD2 index derived from the Poincaré plot, and the sympathetic/parasympathetic ratio (S/PS) to monitor soccer players has been proposed. However, the reliability of these new indices and the ability of HRV to differentiate between soccer competitive levels are unknown. The aim of this study was to analyze the reliability of the different HRV-derived indices in professional soccer players during the competitive period and to compare HRV of professional soccer players from 3 teams of distinct competitive levels (i.e., Italian Second Division [2D], European League [EL], and Champions League [CL]). Fifty-four male professional soccer players from 3 different teams of 2 European countries (Italy and Germany) participated in the study. The intraclass correlation coefficient values of the HRV indices varied from 0.78 (very large) to 0.90 (near perfect). The coefficient of variation (CV) values for RMSSD and SDNN were all soccer players and is able to differentiate between international- and national-level players.

  8. Categorizing Fetal Heart Rate Variability with and without Visual Aids.

    Science.gov (United States)

    Ashdown, Amanda J; Scerbo, Mark W; Belfore, Lee A; Davis, Stephen S; Abuhamad, Alfred Z

    2016-10-01

    Objective This study examined the ability of clinicians to correctly categorize images of fetal heart rate (FHR) variability with and without the use of exemplars. Study Design A sample of 33 labor and delivery clinicians inspected static FHR images and categorized them into one of four categories defined by the National Institute of Child Health and Human Development (NICHD) based on the amount of variability within absent, minimal, moderate, or marked ranges. Participants took part in three conditions: two in which they used exemplars representing FHR variability near the center or near the boundaries of each range, and a third control condition with no exemplars. The data gathered from clinicians were compared with those from a previous study using novices. Results Clinicians correctly categorized more images when the FHR variability fell near the center rather than the boundaries of each range, F (1,32) = 71.69, p visual aids to improve judgments about FHR variability and potentially enhance safety in labor and delivery.

  9. Determining cardiac vagal threshold from short term heart rate complexity

    Directory of Open Access Journals (Sweden)

    Hamdan Rami Abou

    2016-09-01

    Full Text Available Evaluating individual aerobic exercise capacity is fundamental in sports and exercise medicine but associated with organizational and instrumental effort. Here, we extract an index related to common performance markers, the aerobic and anaerobic thresholds enabling the estimation of exercise capacity from a conventional sports watch supporting beatwise heart rate tracking. Therefore, cardiac vagal threshold (CVT was determined in 19 male subjects performing an incremental maximum exercise test. CVT varied around the anaerobic threshold AnT with mean deviation of 7.9 ± 17.7 W. A high correspondence of the two thresholds was indicated by Bland-Altman plots with limits of agreement −27.5 W and 43.4 W. Additionally, CVT was strongly correlated AnT (rp = 0.86, p < 0.001 and reproduced this marker well (rc = 0.81. We conclude, that cardiac vagal threshold derived from compression entropy time course can be useful to assess physical fitness in an uncomplicated way.

  10. Target heart rates for the development of cardiorespiratory fitness.

    Science.gov (United States)

    Swain, D P; Abernathy, K S; Smith, C S; Lee, S J; Bunn, S A

    1994-01-01

    The American College of Sports Medicine (ACSM) recommends the use of 40%, 60%, 80%, and 85% of maximal oxygen consumption (VO2max) as target values in developing exercise prescriptions. Further, the ACSM states that 55%, 70%, 85%, and 90% of maximal heart rate (HRmax) may be used as indices of these respective levels of % VO2max for the general population. The current study evaluated this relationship between %HRmax and %VO2max in apparently healthy, young adults. Eighty-one men and 81 women between the ages of 18 and 34 engaged in an incremental exercise test to exhaustion. Linear regressions of %HRmax and %VO2max were performed on each subject. From these regressions, target values of %HRmax were computed for each individual. Mean percentages of HRmax were 63%, 76%, 89%, and 92% at 40%, 60%, 80%, and 85% of VO2max, respectively. At all of these values of %VO2max, the values obtained for %HRmax were significantly greater (P < 0.001) than those used by the ACSM. Fitness affected these results, particularly among men. High fit men averaged 2% higher in %HRmax than low fit men at any given value of %VO2max.

  11. Short- and long-term variations in non-linear dynamics of heart rate variability

    DEFF Research Database (Denmark)

    Kanters, J K; Højgaard, M V; Agner, E

    1996-01-01

    variability. METHODS: Twelve healthy subjects were investigated by 3-h ambulatory ECG recordings repeated on 3 separate days. Correlation dimension, non-linear predictability, mean heart rate, and heart rate variability in the time and frequency domains were measured and compared with the results from......OBJECTIVES: The purpose of the study was to investigate the short- and long-term variations in the non-linear dynamics of heart rate variability, and to determine the relationships between conventional time and frequency domain methods and the newer non-linear methods of characterizing heart rate...... corresponding surrogate time series. RESULTS: A small significant amount of non-linear dynamics exists in heart rate variability. Correlation dimensions and non-linear predictability are relatively specific parameters for each individual examined. The correlation dimension is inversely correlated to the heart...

  12. Ergodic secret message capacity of the wiretap channel with finite-rate feedback

    KAUST Repository

    Rezki, Zouheir

    2014-06-01

    We study the secret message capacity of an ergodic block fading wiretap channel with partial channel state information at the transmitter and perfect channel state information at the receivers, under both a short term power constraint (STPC) and a long term power constraint (LTPC). We consider that in addition to the statistics of the main and the eavesdropper channel state information (CSI), the sender is provided by the legitimate receiver with a q-bit feedback, at the beginning of each coherence block, through an error-free public channel, with capacity q bits. We establish upper and lower bounds on the secrecy capacity. We show that the lower and the upper bounds coincide asymptotically as q → ∞. When applied to Rayleigh fading channels, we show that, a 4-bit feedback achieves about 90% of the secrecy capacity when perfect main CSI is available at the transmitter. Finally, asymptotic analysis at high and low Signal-to-Noise Ratio (SNR) is presented. It is found that the capacity is bounded at high-SNR, whereas at asymptotically low-SNR, the lower bounds and the upper bound scale linearly with SNR under STPC. Furthermore, subject to LTPC, the capacity at low-SNR is equal to the capacity of the main channel without secrecy constraint and with perfect CSI at both the transmitter and the receiver, under a mild condition on the fading statistics. We also show that a positive secrecy rate is achievable even when the feedback is at the end of each coherence block and q=1. © 2002-2012 IEEE.

  13. Heart rate in pediatric trauma: rethink your strategy.

    Science.gov (United States)

    Ko, Ara; Harada, Megan Y; Murry, Jason S; Nuño, Miriam; Barmparas, Galinos; Ma, Annie A; Thomsen, Gretchen M; Ley, Eric J

    2016-04-01

    The optimal heart rate (HR) for children after trauma is based on values derived at rest for a given age. As the stages of shock are based in part on HR, a better understanding of how HR varies after trauma is necessary. Admission HRs of pediatric trauma patients were analyzed to determine which ranges were associated with lowest mortality. The National Trauma Data Bank was used to evaluate all injured patients ages 1-14 years admitted between 2007 and 2011. Patients were stratified into eight groups based on age. Clinical characteristics and outcomes were recorded, and regression analysis was used to determine mortality odds ratios (ORs) for HR ranges within each age group. A total of 214,254 pediatric trauma patients met inclusion criteria. The average admission HR and systolic blood pressure were 104.7 and 120.4, respectively. Overall mortality was 0.8%. The HR range associated with lowest mortality varied across age groups and, in children ages 7-14, was narrower than accepted resting HR ranges. The lowest risk of mortality for patients ages 5-14 was captured at HR 80-99. The HR associated with lowest mortality after pediatric trauma frequently differs from resting HR. Our data suggest that a 7y old with an HR of 115 bpm may be in stage III shock, whereas traditional HR ranges suggest that this is a normal rate for this child. Knowing when HR is critically high or low in the pediatric trauma population will better guide treatment. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Heart rate variability predicts mortality in peritoneal dialysis patients.

    Science.gov (United States)

    Pei, Juan; Tang, Wen; Li, Li-Xian; Su, Chun-Yan; Wang, Tao

    2015-08-01

    The predictive value of heart rate variability (HRV) in peritoneal dialysis (PD) has never been tested. In this study, the associations between HRV measures and the mortality in 81 PD patients were analyzed. HRV was measured by using 5-min recordings of a stationary system by a standardized method. Both time domain and frequency domain parameters were analyzed. During a follow-up period of 43.78 ± 14.77 months, 25 patients died, four patients were transferred to hemodialysis. Of the 81 patients, the time domain parameters, such as the standard deviation of differences between adjacent normal sinus to normal sinus (NN) intervals (SDSD) and the square root of the mean of the squared differences between adjacent normal NN intervals (RMSSD), were higher; the frequency domain parameters, such as the ratio of low-frequency power to high-frequency power (LF/HF) and the normalized LF, were lower, and the normalized HF was higher in the non-survived group as compared with the survived group. A Cox proportional hazards model analysis revealed that, of the HRV measures, decrease of the normalized LF, LF/HF and increase of rMSSD, SDSD, normalized HF had significant predictive value for mortality. After adjustment for other univariate predictors including age, urine volume, renal Kt/V, high-sensitivity C-reactive protein (hs-CRP), the predictive value of decreased LF/HF remained significant. Kaplan-Meier survival analysis showed mortality rate was much higher in patients with a low LF/HF (median value of 1.56). The decreases of LF/HF which reflects impaired sympathetic nerve regulation is an independent predictor of mortality in PD patients.

  15. Heart rate variability analysis using robust period detection.

    Science.gov (United States)

    Skotte, Jørgen H; Kristiansen, Jesper

    2014-09-23

    Heart rate variability (HRV) analysis, which is an important tool for activity assessment of the cardiac autonomic nervous system, very often includes the estimation of power spectra for series of interbeat intervals (IBI). Ectopic beats and artifacts have a destructive effect on the standard methods (Fourier transform, FFT) for frequency analysis. This study investigates an alternative method for calculation of the periodogram using a robust period detection (RPD). Error free IBI series of 5 minutes for 221 subjects during one day were artificially distorted by randomly changing IBI values by ±15-40%. The low to high frequency rate (LF/HF) were calculated from periodograms estimated by the FFT, RPD and Lomb (LSP) methods for both error free and distorted series and for series with removed beats. Log transformed LF/HF values for series with distorted/removed beats were compared to undistorted values by linear regression. For series with 10% of distorted IBI values the regression analysis between distorted and undistorted series showed a goodness of fit, coefficient and intercept of 0.98, 0.94 and 0.02, respectively. In comparison, the values of these parameters were (0.34, 0.46, -1.61) and (0.28, 0.42,-1.32) for the FFT and LSP methods, respectively. Similarly, the comparison between series with removed and undistorted beats yielded goodness of fit, coefficient and intercept of (0.98, 0.96, -0.01), (0.93, 0.78, -0.02) and (0.98, 0.95, 0.19) for RPD, FFT and LSP, respectively. The RPD method demonstrated superior performance compared to the FFT and LSP method by estimation of power spectral characteristics for HRV analysis.

  16. HEART RATE VARIABILITY IN PREGNANT WOMEN WITH VENTRICULAR EXTRASYSTOLES

    Directory of Open Access Journals (Sweden)

    Yevgeniya Chekashkina

    2016-03-01

    Full Text Available Frequent ventricular extrasystoles (VE can affect haemodynamic indexes and lead to negative consequences for the health of not only an expectant mother, but also a fetus. The analysis of heart rate variability (HRV is recognized as an informative method for noninvasive assessment of the impact of the autonomic nervous system on the cardiovascular system. HRV in pregnant women has been understudied. Therefore, the goal of the present research is to investigate HRV indexes in pregnant women with frequent VE in the 3-rd trimester of pregnancy and early postnatal period. Materials and Methods HRV was estimated in 40 pregnant women with frequent VE, who were divided into 2 groups: group 1– in the 3-rd trimester of pregnancy, and group 2 – in the early postnatal period. A control group included 20 normal pregnant women without any arrhythmias. In addition, HRV indexes in these groups were compared to the indexes in the group of healthy non-pregnant women at the age of 18 to 30. The investigation of HRV was conducted by using the 24-hour HM-ECG with “Valenta” cardioregistrator (Russia. SDNN, SDAN, HRVi, HF, LF, VLF and LF/HF indexes of HRV were under the study. Results The analysis of time indexes revealed the decreased of HRV during pregnancy: in the 3-rd trimester SDNN decreased. In the postnatal period SDNN increased. It was found that rMSSD decresed in pregnant women and increased in the postnatal period that is indicative of enhanced parasympathetic effects. Similar dynamics was noted in analyzing the HF index associated with vagal activity. Vagal activity tended to decrease in pregnancy as compared to its normal values and increased significantly in the early postnatal period. We sould note that the LF waves activity reflecting the sympathetic effects on the heart increased gradually in pregnant women and decreased in the postnatal period. Discussion and Conclusions The investigation of HRV allows to estimate an extent of the autonomic

  17. Effects of Exercise Training on Heart Rate Variability in Chagas Heart Disease

    Directory of Open Access Journals (Sweden)

    Bruno Ramos Nascimento

    2014-09-01

    Full Text Available Background: Heart rate variability (HRV is a marker of autonomic dysfunction severity. The effects of physical training on HRV indexes in Chagas heart disease (CHD are not well established. Objective: To evaluate the changes in HRV indexes in response to physical training in CHD. Methods: Patients with CHD and left ventricular (LV dysfunction, physically inactive, were randomized either to the intervention (IG, N = 18 or control group (CG, N = 19. The IG participated in a 12-week exercise program consisting of 3 sessions/week. Results: Mean age was 49.5 ± 8 years, 59% males, mean LVEF was 36.3 ± 7.8%. Baseline HRV indexes were similar between groups. From baseline to follow-up, total power (TP: 1653 (IQ 625 - 3418 to 2794 (1617 - 4452 ms, p = 0.02 and very low frequency power: 586 (290 - 1565 to 815 (610 - 1425 ms, p = 0.047 increased in the IG, but not in the CG. The delta (post - pre HRV indexes were similar: SDNN 11.5 ± 30.0 vs. 3.7 ± 25.1 ms. p = 0.10; rMSSD 2 (6 - 17 vs. 1 (21 - 9 ms. p = 0.43; TP 943 (731 - 3130 vs. 1780 (921 - 2743 Hz. p = 0.46; low frequency power (LFP 1.0 (150 - 197 vs. 60 (111 - 146 Hz. p = 0.85; except for high frequency power, which tended to increase in the IG: 42 (133 - 92 vs. 79 (61 - 328 Hz. p = 0.08. Conclusion: In the studied population, the variation of HRV indexes was similar between the active and inactive groups. Clinical improvement with physical activity seems to be independent from autonomic dysfunction markers in CHD.

  18. Impact of sleep-disordered breathing on heart rate turbulence in heart failure patients.

    Directory of Open Access Journals (Sweden)

    Akiomi Yoshihisa

    Full Text Available BACKGROUND: Sleep-disordered breathing (SDB is associated with adverse outcomes in patients with chronic heart failure (CHF. Additionally, heart rate turbulence (HRT reflects changes in the sinus cycle length of baroreceptor in response to hemodynamic fluctuations after ventricular premature beat. Recent studies have suggested that HRT as a marker of vagal activity has a predictive value of poor prognosis in CHF patients. However, little is known about the relationship between SDB and HRT in CHF patients. METHODS AND RESULTS: In this study, 75 patients with CHF were enrolled. We simultaneously performed Holter ECG during a 24-hr period and portable sleep monitoring at nighttime, and determined the respiratory disturbance index (RDI, HRT (turbulence onset (TO and turbulence slope (TS during that 24-hr period. These patients were divided into two groups based on the presence of severe SDB: Group A (RDI≥30, n = 17 and Group B (RDI<30, n = 58. TS was significantly lower in Group A than in Group B across the 24-hr period (nighttime: 3.6±1.1 vs. 6.9±1.3; daytime: 3.7±0.8 vs. 7.0±1.1; all-day: 3.5±0.7 vs. 6.7±0.9% ms/RR, P<0.05, respectively. TO did not differ between the two groups. Furthermore, there was a significant negative correlation between all-day TS and RDI (R = -0.257, P = 0.027. Moreover, in the multiple regression analysis, RDI was an independent factor to determine all-day TS. CONCLUSIONS: In patients with severe SDB, blunted TS was observed across 24 hours. These results suggest that SDB induce impairment of vagal activity across a 24-hour period and may be associated with poor prognosis in CHF patients.

  19. Prognostic impact of heart rate in elderly with systolic heart failure and concomitant atrial fibrillation.

    Science.gov (United States)

    Barywani, Salim; Petzold, Max

    2017-08-01

    The present study aimed to investigate the impact of resting heart rate (HR) on 5-year all-cause mortality in patients ≥80 years with heart failure (HF) with reduced ejection fraction (HFrEF) and concomitant atrial fibrillation (AF) after optimal up-titration of beta-blockers (BBs). Patients (n = 185) aged ≥80 years with HF and left ventricular ejection fraction ≤40% were included between January 2000 and January 2008 from two university hospitals, Sahlgrenska and Östra and retrospectively studied from January 2 to May 30, 2013. Up-titrations of guideline recommended medications were performed at HF outpatient clinics. Of whole study population, 54% (n= 100) had AF. After optimal up-titration of BBs and angiotensin converting enzyme inhibitors (ACEIs)/angiotensin receptor blockers (ARBs), mean HR in patients with AF was 73 ± 15 beats/minute (bpm), 36% had resting HR ≤65 bpm. Five-year all-cause mortality among patients with AF was significantly lower in patients with HR ≤65 bpm (63%) compared to HR >65 (80%). Cox proportional-hazard regression analysis adjusted for clinically important baseline variables and doses of ACEIs/ARBs and BBs demonstrated resting HR ≤65 bpm as an independent predictor of improved survival compared to resting HR >65 bpm (HR 0.3, 95%CI 0.1-0.7, P 0.005). In octogenarians with HFrEF and concomitant AF, lowering resting HR to levels as low as HR ≤65 bpm was still associated with improved survival from all-cause mortality. Our data indicate that mortality in AF became comparable to SR when patients were on maximally up-titrated beta-blocker doses with HR as low as 75 bpm.

  20. Low-Bit Rate Feedback Strategies for Iterative IA-Precoded MIMO-OFDM-Based Systems

    Directory of Open Access Journals (Sweden)

    Sara Teodoro

    2014-01-01

    Full Text Available Interference alignment (IA is a promising technique that allows high-capacity gains in interference channels, but which requires the knowledge of the channel state information (CSI for all the system links. We design low-complexity and low-bit rate feedback strategies where a quantized version of some CSI parameters is fed back from the user terminal (UT to the base station (BS, which shares it with the other BSs through a limited-capacity backhaul network. This information is then used by BSs to perform the overall IA design. With the proposed strategies, we only need to send part of the CSI information, and this can even be sent only once for a set of data blocks transmitted over time-varying channels. These strategies are applied to iterative MMSE-based IA techniques for the downlink of broadband wireless OFDM systems with limited feedback. A new robust iterative IA technique, where channel quantization errors are taken into account in IA design, is also proposed and evaluated. With our proposed strategies, we need a small number of quantization bits to transmit and share the CSI, when comparing with the techniques used in previous works, while allowing performance close to the one obtained with perfect channel knowledge.

  1. Low-Bit Rate Feedback Strategies for Iterative IA-Precoded MIMO-OFDM-Based Systems

    Science.gov (United States)

    Teodoro, Sara; Silva, Adão; Dinis, Rui; Gameiro, Atílio

    2014-01-01

    Interference alignment (IA) is a promising technique that allows high-capacity gains in interference channels, but which requires the knowledge of the channel state information (CSI) for all the system links. We design low-complexity and low-bit rate feedback strategies where a quantized version of some CSI parameters is fed back from the user terminal (UT) to the base station (BS), which shares it with the other BSs through a limited-capacity backhaul network. This information is then used by BSs to perform the overall IA design. With the proposed strategies, we only need to send part of the CSI information, and this can even be sent only once for a set of data blocks transmitted over time-varying channels. These strategies are applied to iterative MMSE-based IA techniques for the downlink of broadband wireless OFDM systems with limited feedback. A new robust iterative IA technique, where channel quantization errors are taken into account in IA design, is also proposed and evaluated. With our proposed strategies, we need a small number of quantization bits to transmit and share the CSI, when comparing with the techniques used in previous works, while allowing performance close to the one obtained with perfect channel knowledge. PMID:24678274

  2. Using Complexity Metrics With R-R Intervals and BPM Heart Rate Measures

    DEFF Research Database (Denmark)

    Wallot, Sebastian; Fusaroli, Riccardo; Tylén, Kristian

    2013-01-01

    on variability of the data, different choices regarding the kind of measures can have a substantial impact on the results. In this article we compare linear and non-linear statistics on two prominent types of heart beat data, beat-to-beat intervals (R-R interval) and beats-per-minute (BPM). As a proof...... of interpersonal coordination. However, there is no consensus about which measurements and analytical tools are most appropriate in mapping the temporal dynamics of heart rate and quite different metrics are reported in the literature. As complexity metrics of heart rate variability depend critically......-of-concept, we employ a simple rest-exercise-rest task and show that non-linear statistics – fractal (DFA) and recurrence (RQA) analyses – reveal information about heart beat activity above and beyond the simple level of heart rate. Non-linear statistics unveil sustained post-exercise effects on heart rate...

  3. Relationship between obesity, negative affect and basal heart rate in predicting heart rate reactivity to psychological stress among adolescents.

    Science.gov (United States)

    Park, Andres E; Huynh, Pauline; Schell, Anne M; Baker, Laura A

    2015-08-01

    Reduced cardiovascular responses to psychological stressors have been found to be associated with both obesity and negative affect in adults, but have been less well studied in children and adolescent populations. These findings have most often been interpreted as reflecting reduced sympathetic nervous system response, perhaps associated with heightened baseline sympathetic activation among the obese and those manifesting negative affect. However, obesity and negative affect may themselves be correlated, raising the question of whether they both independently affect cardiovascular reactivity. The present study thus examined the separate effects of obesity and negative affect on both cardiovascular and skin conductance responses to stress (e.g., during a serial subtraction math task) in adolescents, while controlling for baseline levels of autonomic activity during rest. Both obesity and negative affect had independent and negative associations with cardiovascular reactivity, such that reduced stress responses were apparent for obese adolescents and those with high levels of negative affect. In contrast, neither obesity nor negative affect was related to skin conductance responses to stress, implicating specifically noradrenergic mechanisms rather than sympathetic mechanisms generally as being deficient. Moreover, baseline heart rate was unrelated to obesity in this sample, which suggests that heightened baseline of sympathetic activity is not necessary for the reduced cardiovascular reactivity to stress. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Association between the Rating Perceived Exertion, Heart Rate and Blood Lactate in Successive Judo Fights (Randori)

    Science.gov (United States)

    Branco, Braulio H.M.; Massuça, Luis M.; Andreato, Leonardo V.; Marinho, Bruno F.; Miarka, Bianca; Monteiro, Luis; Franchini, Emerson

    2013-01-01

    Purpose This study aims to investigate the association between the rating of perceived exertion (RPE), heart rate (HR) and the blood lactate concentration ([La]) in successive judo fight simulations (randori). Methods Ten athletes participated in the study (age: 25.6±2.1 years; stature: 1.75±0.07 m; body mass: 75.6±14.9kg; %BF: 11.5±7.8%; practice: 14.5±6.2 years) and completed 4 judo fight simulations (T1 to T4) with duration of 5 min separated by 5 min passive recovery periods. Before each randori, [La] and HR were collected, and after each randori, the same measures and the RPE (CR-10 scale) were collected. Results Significant correlations were observed between: (1) CR-10 and HR (T2: r =0.70; T3: r =0.64; both, Pjudo fight simulations (Pjudo, should be done with caution. PMID:23802054

  5. Influence of proprioceptive feedback on the firing rate and recruitment of motoneurons

    Science.gov (United States)

    De Luca, C. J.; Kline, J. C.

    2012-02-01

    We investigated the relationships of the firing rate and maximal recruitment threshold of motoneurons recorded during isometric contraction with the number of spindles in individual muscles. At force levels above 10% of maximal voluntary contraction, the firing rate was inversely related to the number of spindles in a muscle, with the slope of the relationship increasing with force. The maximal recruitment threshold of motor units increased linearly with the number of spindles in the muscle. Thus, muscles with a greater number of spindles had lower firing rates and a greater maximal recruitment threshold. These findings may be explained by a mechanical interaction between muscle fibres and adjacent spindles. During low-level (0% to 10%) voluntary contractions, muscle fibres of recruited motor units produce force twitches that activate nearby spindles to respond with an immediate excitatory feedback that reaches maximal level. As the force increases further, the twitches overlap and tend towards tetanization, the muscle fibres shorten, the spindles slacken, their excitatory firings decrease, and the net excitation to the homonymous motoneurons decreases. Motoneurons of muscles with greater number of spindles receive a greater decrease in excitation which reduces their firing rates, increases their maximal recruitment threshold, and changes the motoneuron recruitment distribution.

  6. Wave reflections, arterial stiffness, heart rate variability and orthostatic hypotension.

    Science.gov (United States)

    Lu, Dai-Yin; Sung, Shih-Hsien; Yu, Wen-Chung; Cheng, Hao-Min; Chuang, Shao-Yuan; Chen, Chen-Huan

    2014-12-01

    Increased arterial stiffness and wave reflections are independently associated with orthostatic hypotension (OH). This study investigated whether heart rate variability (HRV) is also involved in the modulation of orthostatic blood pressure (BP) change. A total of 429 subjects (65.1 ± 16.4 years, 77.4% men) were enrolled in this study. OH was defined as a ⩾ 20 mm Hg decrease in brachial systolic blood pressure (SBP) or a ⩾ 10 mm Hg diastolic blood pressure (DBP) decrease upon standing. Measurements of carotid-femoral pulse wave velocity (cf-PWV) and the amplitude of the reflected pressure wave from a decomposed carotid pressure wave (Pb) were obtained by carotid tonometry in the supine position. The power spectrum from a 5-min recording of an electrocardiogram at rest was analyzed to provide components in the high frequency (HF) and low frequency (LF) ranges. Subjects with OH (n = 59, 13.8%) had significantly higher cf-PWV and Pb and significantly lower LogHF and LogLF than those without OH (n = 370). The cf-PWV, Pb, LogHF and LogLF were significantly associated with postural SBP and DBP changes. Furthermore, cf-PWV but not Pb was significantly associated with LogHF and LogLF. Multivariate analysis showed that Pb (odds ratio (OR) per 1 s.d. 1.65, 95% confidence interval (CI) 1.282-2.137; P = 0.003) and LogHF (OR 0.628, 95% CI 0.459-0.860, P = 0.004), but not cf-PWV (OR 1.279, 95% CI 0.932-1.755, P = 0.128), were significant independent determinants of OH. Increased wave reflections may predispose OH independently of arterial stiffness and HRV. In contrast, increased arterial stiffness may cause OH through the modulation of HRV.

  7. Reiki improves heart rate homeostasis in laboratory rats.

    Science.gov (United States)

    Baldwin, Ann Linda; Wagers, Christina; Schwartz, Gary E

    2008-05-01

    To determine whether application of Reiki to noise-stressed rats can reduce their heart rates (HRs) and blood pressures. In a previous study, we showed that exposure of rats to 90 dB white noise for 15 minutes caused their HRs and blood pressures to significantly increase. Reiki has been shown to significantly decrease HR and blood pressure in a small group of healthy human subjects. However, use of humans in such studies has the disadvantage that experimental interpretations are encumbered by the variable of belief or skepticism regarding Reiki. For that reason, noise-stressed rats were used as an animal model to test the efficacy of Reiki in reducing elevated HR and blood pressure. Three unrestrained, male Sprague-Dawley rats implanted with radiotelemetric transducers were exposed daily for 8 days to a 15-minute white noise regimen (90 dB). For the last 5 days, the rats received 15 minutes of Reiki immediately before the noise and during the noise period. The experiment was repeated on the same animals but using sham Reiki. The animals were housed in a quiet room in University of Arizona Animal Facility. Mean HRs and blood pressure were determined before Reiki/sham Reiki, during Reiki/sham Reiki, and during the noise in each case. Reiki, but not sham Reiki, significantly reduced HR compared to initial values. With Reiki, there was a high correlation between change in HR and initial HR, suggesting a homeostatic effect. Reiki, but not sham Reiki, significantly reduced the rise in HR produced by exposure of the rats to loud noise. Neither Reiki nor sham Reiki significantly affected blood pressure. Reiki is effective in modulating HR in stressed and unstressed rats, supporting its use as a stress-reducer in humans.

  8. Gum chewing modulates heart rate variability under noise stress.

    Science.gov (United States)

    Ekuni, Daisuke; Tomofuji, Takaaki; Takeuchi, Noriko; Morita, Manabu

    2012-12-01

    Gum chewing may relieve stress, although this hypothesis has not been proven. Heart-rate variability (HRV) is commonly used to measure stress levels. However, it is not known if gum chewing modulates HRV under acute stress. The aim of this study was to investigate the effects of gum chewing on HRV under acute stress. A cross-over study involving 47 non-smoking healthy subjects, aged 22-27 years, was carried out. The subjects received a stress procedure with gum chewing (GS group) and without gum chewing (S group). Additionally, the other 20 subjects were allocated to the gum chewing without stress group (G group). The GS and S groups were exposed to noise for 5 min (75 dBA) as stress. Before and after stress exposure/gum chewing, participants completed the state portion of the State-Trait Anxiety Inventory (STAI-s) and a single Stress Visual Analogue Scale (VAS) measurement. HRV measurement was performed before and during stress/gum chewing for 5 min. After the stress procedure, VAS score significantly increased in the GS and S groups. During the stress procedure, the GS group showed a significantly lower level of high frequency (HF) and higher levels of low frequency (LF) and LF/HF than the S group. However, there were no significant differences in the scores of the state portion of the State-Trait Anxiety Inventory (STAI-s) and VAS between the two stress groups. These findings suggest that gum chewing modulates HRV, but may not relieve acute stress caused by noise.

  9. Association of Fetal Heart Rate Baseline Change and Neonatal Outcomes.

    Science.gov (United States)

    Yang, Michael; Stout, Molly J; López, Julia D; Colvin, Ryan; Macones, George A; Cahill, Alison G

    2017-07-01

    Objective The objective of this study was to describe the incidence of baseline change within normal range during labor and its prediction of neonatal outcomes. Materials and Methods This was a prospective cohort of singleton, nonanomalous, term neonates with continuous electronic fetal monitoring and normal baseline fetal heart rate throughout the last 2 hours of labor. We determined baseline in 10-minute segments using Eunice Kennedy Shriver National Institute of Child Health and Human Development criteria. We evaluated baseline changes of ≥ 20 and ≥ 30 bpm for association with acidemia (umbilical cord arterial pH ≤ 7.10) and neonatal intensive care unit (NICU) admission. Finally, we performed a sensitivity analysis of normal neonates, excluding those with acidemia, NICU admission, or 5-minute Apgar bpm; 272 (9.0%) had ≥ 30 bpm. Among normal neonates (n = 2,939), 1,221 (41.5%) had change ≥20 bpm. Acidemia was not associated with baseline change of any direction or magnitude. NICU admission was associated with decrease ≥ 20 bpm (adjusted odds ratio [aOR]: 2.93; 95% confidence interval [CI]: 1.19 - 7.21) or any direction ≥ 20 bpm (aOR: 4.06; 95% CI: 1.46-11.29). For decrease ≥ 20 bpm, sensitivity and specificity were 40.0 and 81.7%; for any direction ≥ 20 bpm, 75.0 and 58.3%. Conclusion Changes of normal baseline are common in term labor and poorly predict morbidity, regardless of direction or magnitude. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  10. Isoflurane depresses baroreflex control of heart rate in decerebrate rats.

    Science.gov (United States)

    Lee, Jong S; Morrow, Don; Andresen, Michael C; Chang, Kyoung S K

    2002-05-01

    Isoflurane inhibits baroreflex control of heart rate (HR) by poorly understood mechanisms. The authors examined whether suprapontine central nervous system cardiovascular regulatory sites are required for anesthetic depression. The effects of isoflurane (1 and 2 rat minimum alveolar concentration [MAC]) on the baroreflex control of HR were determined in sham intact and midcollicular-transected decerebrate rats. Intravenous phenylephrine (0.2-12 microg/kg) and nitroprusside (1-60 microg/kg) were used to measure HR responses to peak changes in mean arterial pressure (MAP). Sigmoidal logistic curve fits to HR-MAP data assessed baroreflex sensitivity (HR/MAP), HR range, lower and upper HR plateau, and MAP at half the HR range (BP50). Four groups (two brain intact and two decerebrate) were studied before, during, and after isoflurane. To assess sympathetic and vagal contributions to HR baroreflex, beta-adrenoceptor (1 mg/kg atenolol) or muscarinic (0.5 mg/kg methyl atropine) antagonists were administered systemically. Decerebration did not alter resting MAP and HR or baroreflex parameters. Isoflurane depressed baroreflex slope and HR range in brain-intact and decerebrate rats. In both groups, 1 MAC reduced HR range by depressing peak reflex tachycardia. Maximal reflex bradycardia during increases in blood pressure was relatively preserved. Atenolol during 1 MAC did not alter maximum reflex tachycardia. In contrast, atropine during 1 MAC fully blocked reflex bradycardia. Therefore, 1 MAC predominantly depresses sympathetic components of HR baroreflex. Isoflurane at 2 MAC depressed both HR plateaus and decreased BP50 in both groups. Isoflurane depresses HR baroreflex control by actions that do not require suprapontine central nervous system sites. Isoflurane actions seem to inhibit HR baroreflex primarily by the sympathetic nervous system.

  11. Postural Heart Rate Changes in Young Patients With Vasovagal Syncope.

    Science.gov (United States)

    Medow, Marvin S; Merchant, Sana; Suggs, Melissa; Terilli, Courtney; O'Donnell-Smith, Breige; Stewart, Julian M

    2017-04-01

    Recurrent postural vasovagal syncope (VVS) is caused by transient cerebral hypoperfusion from episodic hypotension and bradycardia; diagnosis is made by medical history. VVS contrasts with postural tachycardia syndrome (POTS), defined by chronic daily symptoms of orthostatic intolerance with excessive upright tachycardia without hypotension. POTS has recently been conflated with VVS when excessive tachycardia is succeeded by hypotension during tilt testing. We hypothesize that excessive tachycardia preceding hypotension and bradycardia is part of the vasovagal response during tilt testing of patients with VVS. We prospectively performed head-up tilt (HUT) testing on patients with recurrent VVS (n = 47, 17.9 ± 1.1 y), who fainted at least 3 times within the last year, and control subjects (n = 15, 17.1 ± 1.0 y), from age and BMI-matched volunteers and measured blood pressure, heart rate (HR), cardiac output, total peripheral resistance, and end tidal carbon dioxide. Baseline parameters were the same in both groups. HR (supine versus 5 and 10 minutes HUT) significantly increased in control (65 ± 2.6 vs 83 ± 3.6 vs 85 ± 3.7, P < .001) and patients with VVS (69 ± 1.6 vs 103 ± 2.3 vs 109 ± 2.4, P < .001). HUT in controls maximally increased HR by 20.3 ± 2.9 beats per minute; the increase in patients with VVS of 39.8 ± 2.1 beats per minute was significantly greater (P < .001). An increase in HR of ≥40 beats per minute by 5 and 10 minutes or before faint with HUT, occurred in 26% and 44% of patients with VVS, respectively, but not in controls. Orthostasis in VVS is accompanied by large increases in HR that should not be construed as POTS. Copyright © 2017 by the American Academy of Pediatrics.

  12. Heart rate variability (HRV): an indicator of stress

    Science.gov (United States)

    Kaur, Balvinder; Durek, Joseph J.; O'Kane, Barbara L.; Tran, Nhien; Moses, Sophia; Luthra, Megha; Ikonomidou, Vasiliki N.

    2014-05-01

    Heart rate variability (HRV) can be an important indicator of several conditions that affect the autonomic nervous system, including traumatic brain injury, post-traumatic stress disorder and peripheral neuropathy [3], [4], [10] & [11]. Recent work has shown that some of the HRV features can potentially be used for distinguishing a subject's normal mental state from a stressed one [4], [13] & [14]. In all of these past works, although processing is done in both frequency and time domains, few classification algorithms have been explored for classifying normal from stressed RRintervals. In this paper we used 30 s intervals from the Electrocardiogram (ECG) time series collected during normal and stressed conditions, produced by means of a modified version of the Trier social stress test, to compute HRV-driven features and subsequently applied a set of classification algorithms to distinguish stressed from normal conditions. To classify RR-intervals, we explored classification algorithms that are commonly used for medical applications, namely 1) logistic regression (LR) [16] and 2) linear discriminant analysis (LDA) [6]. Classification performance for various levels of stress over the entire test was quantified using precision, accuracy, sensitivity and specificity measures. Results from both classifiers were then compared to find an optimal classifier and HRV features for stress detection. This work, performed under an IRB-approved protocol, not only provides a method for developing models and classifiers based on human data, but also provides a foundation for a stress indicator tool based on HRV. Further, these classification tools will not only benefit many civilian applications for detecting stress, but also security and military applications for screening such as: border patrol, stress detection for deception [3],[17], and wounded-warrior triage [12].

  13. Heart Rate Response of Professional Musicians When Playing Music.

    Science.gov (United States)

    Vellers, Heather L; Irwin, Conor; Lightfoot, J T

    2015-06-01

    The primary aim was to determine the level of physiological stress evoked while playing music in a standing position as indicated by heart rate (HR) response. A secondary aim was to analyze the effect of music genre (classic rock, western, contemporary Christian, and metal rock) on the relative HR response. Lastly, we considered potential physiological initiators of the music-playing-induced HR response. HR response was monitored in 27 professional musicians (3 women, 24 men) between the ages of 21 and 67 yrs old during rehearsal and public performances. The percent maximal HR (%MHR) evoked was determined by taking a percentage of the age-predicted maximal HR for each musician and comparing the average %MHR in each genre during public and rehearsal events. The role of the potential initiators of these responses (e.g., number of years playing in public, event type, instrument type, tempo, etc.) was determined using multiple regression analyses. The overall average %MHR responses were 52 ± 5% and 59 ± 5% during rehearsal and public performances, respectively, with genre type having a significant effect on the HR response (p=0.01). Body mass index and tempo were each found to be significant contributors to the HR response while playing music (r²=0.506, p=0.001). Playing music professionally evokes considerable increases in HR response, with music genre influencing the level of the physiological response. We concluded that 50% of the HR response while playing music was associated with body mass index, music tempo, and instrument type.

  14. VASCULAR REMODELING AND HEART RATE VARIABILITY IN DIFFERENT ANTIHYPERTENSIVE THERAPIES

    Directory of Open Access Journals (Sweden)

    E. D. Golovanova

    2008-01-01

    Full Text Available Aim. To study the effect of the long-term antihypertensive monotherapy with indapamide (Arifon Retard, 1,5 mg/d, metoprolol tartrate (Egilok Retard, 50 mg/d and combined therapy with indapamide and perindopril (Noliprel Forte, 1 tab/d: perindopril 4 mg and indapamide 1,25 mg on pulse wave velocity (PWV, cardio-ankle vascular index (CAVI and the sympathetic system activity.Material and methods. 88 patients, aged 30-59 y.o. (32 normotensive patients, 56 with arterial hypertension [HT] of 1-2 grades were examined. Biological age (BA was determined by the linear regression and the vascular wall age (VWA was estimated with the use of volume sphygmography (“VaSera-1000”, “Fucuda Denshi”, Japan. 39 patients with HT were randomized into 3 parallel groups with studied therapies lasted for 6 months. PWV, CAVI of the vessels of elastic, muscular and mixed types, blood pressure, measured in upper and lower extremities and heart rate variability (HRV were determined before and at the end of the therapies.Results. BA and VWA were elevated in all of patients with HT as compared with normotensive patients. The reduction in PWV and CAVI of the vessels of elastic and mixed types, HRV increase were found in patients with Arifon Retard monotherapy. Monotherapy with metoprolol significantly improved HVR without any influence on the vascular remodeling. Noliprel Forte significantly decreased in blood pressure in the upper and lower extremities, PWV and CAVI of the vessels of all types, decreased in VWA and increased in parasympathetic drive.Conclusion. Long-term therapy with Arifon Retard and Noliprel Forte resulted in decrease in vascular remodeling and increase in HRV simultaneously with significant antihypertensive effect in patients with HT. Metoprolol low doses therapy resulted in normalization of autonomic drive independently on antihypertensive action.

  15. Estimating mental fatigue based on electroencephalogram and heart rate variability

    Science.gov (United States)

    Zhang, Chong; Yu, Xiaolin

    2010-01-01

    The effects of long term mental arithmetic task on psychology are investigated by subjective self-reporting measures and action performance test. Based on electroencephalogram (EEG) and heart rate variability (HRV), the impacts of prolonged cognitive activity on central nervous system and autonomic nervous system are observed and analyzed. Wavelet packet parameters of EEG and power spectral indices of HRV are combined to estimate the change of mental fatigue. Then wavelet packet parameters of EEG which change significantly are extracted as the features of brain activity in different mental fatigue state, support vector machine (SVM) algorithm is applied to differentiate two mental fatigue states. The experimental results show that long term mental arithmetic task induces the mental fatigue. The wavelet packet parameters of EEG and power spectral indices of HRV are strongly correlated with mental fatigue. The predominant activity of autonomic nervous system of subjects turns to the sympathetic activity from parasympathetic activity after the task. Moreover, the slow waves of EEG increase, the fast waves of EEG and the degree of disorder of brain decrease compared with the pre-task. The SVM algorithm can effectively differentiate two mental fatigue states, which achieves the maximum classification accuracy (91%). The SVM algorithm could be a promising tool for the evaluation of mental fatigue. Fatigue, especially mental fatigue, is a common phenomenon in modern life, is a persistent occupational hazard for professional. Mental fatigue is usually accompanied with a sense of weariness, reduced alertness, and reduced mental performance, which would lead the accidents in life, decrease productivity in workplace and harm the health. Therefore, the evaluation of mental fatigue is important for the occupational risk protection, productivity, and occupational health.

  16. An Adaptive Learning Rate for RBFNN Using Time-Domain Feedback Analysis

    Directory of Open Access Journals (Sweden)

    Syed Saad Azhar Ali

    2014-01-01

    Full Text Available Radial basis function neural networks are used in a variety of applications such as pattern recognition, nonlinear identification, control and time series prediction. In this paper, the learning algorithm of radial basis function neural networks is analyzed in a feedback structure. The robustness of the learning algorithm is discussed in the presence of uncertainties that might be due to noisy perturbations at the input or to modeling mismatch. An intelligent adaptation rule is developed for the learning rate of RBFNN which gives faster convergence via an estimate of error energy while giving guarantee to the l2 stability governed by the upper bounding via small gain theorem. Simulation results are presented to support our theoretical development.

  17. Upper stellar mass limit by radiative feedback at low-metallicities: metallicity and accretion rate dependence

    Science.gov (United States)

    Fukushima, Hajime; Omukai, Kazuyuki; Hosokawa, Takashi

    2018-02-01

    We investigate the upper stellar mass limit set by radiative feedback for a forming star with various accretion rates and metallicities. Thus, we numerically solve the structures of both a protostar and its surrounding accretion envelope assuming a spherical symmetric and steady flow. The optical depth of the dust cocoon, a dusty part of the accretion envelope, differs for direct light from the stellar photosphere and diffuse light re-emitted as dust thermal emission. As a result, varying the metallicity qualitatively changes the way that the radiative feedback suppresses the accretion flow. With a fixed accretion rate of 10-3 M⊙ yr-1, both direct and diffuse light jointly operate to prevent mass accretion at Z ≳ 10-1 Z⊙. At Z ≲ 10-1 Z⊙, the diffuse light is no longer effective and the direct light solely limits the mass accretion. At Z ≲ 10-3 Z⊙, formation of the H II region plays an important role in terminating the accretion. The resultant upper mass limit increases with decreasing metallicity, from a few × 10 M⊙ to ∼103 M⊙ over Z = 1 Z⊙-10-4 Z⊙. We also illustrate how the radiation spectrum of massive star-forming cores changes with decreasing metallicity. First, the peak wavelength of the spectrum, which is located around 30 μm at 1 Z⊙, shifts to < 3 μm at Z ≲ 0.1 Z⊙. Secondly, a characteristic feature at 10 μm due to the amorphous silicate band appears as a dip at 1 Z⊙, but changes to a bump at Z ≲ 0.1 Z⊙. Using these spectral signatures, we can search massive accreting protostars in nearby low-metallicity environments with upcoming observations.

  18. RPE-derived work rates can be accurately produced without external feedback or reference to the RPE Scale.

    Science.gov (United States)

    Mauger, Alexis R; Huntley, Tabo; Fletcher, Iain M

    2014-04-01

    Ratings of perceived exertion (RPE) are used to prescribe exercise intensity. This study assessed whether the accurate production of exercise intensity is affected when the rater cannot see the RPE scale. After completing a graded exercise test, 15 active, male participants (M age = 34, SD = 6.7 yr.; M mass = 73.9, SD = 14.8kg, M height = 1.74, SD = 0.08m) completed 3 x 4 min. cycling trials at four randomised RPE-based intensities (RPEs 11, 13, 15, and 17). Participants were allocated to a Full feedback group or a No feedback group (RPEs not in view). On the third trial, No feedback conditions were imposed on the Full feedback group. No statistically significant differences between groups' mean work rates were observed. Changing from Full feedback to No feedback conditions led to a significant overestimation between the trials for power output at RPE 11. Intra-class correlations were significant at RPEs 11, 13, and 17 between all trials for both conditions. Provided adequate familiarisation, active participants can accurately produce RPE derived work rates, even when RPE is not in view.

  19. The Predictive Value of Resting Heart rate Following Osmotherapy in Brain injury: Back to Basics

    Directory of Open Access Journals (Sweden)

    Mahsa Hasanpour Mir

    2012-12-01

    Full Text Available Background: The importance of resting heart rate as a prognostic factor was described in several studies. An elevated heart rate is an independent risk factor for adverse cardiovascular events and total mortality in patients with coronary artery disease, chronic heart failure, and the general population. Also heart rate is elevated in the Multi Organ Dysfunction Syndrome (MODS and the mortality due to MODS is highly correlated with inadequate sinus tachycardia.To evaluate the value of resting heart rate in predicting mortality in patients with traumatic brain injury along scoring systems like Acute Physiology and Chronic Health Evaluation(APACHE II, Sequential Organ Failure Assessment (SOFA and Glasgow Coma Score (GCS.Method: By analyzing data which was collected from an open labeled randomized clinical trial that compared the different means of osmotherapy (mannitol vs bolus or infusion hypertonic saline, heart rate, GCS, APACHE II and SOFA score were measured at baseline and daily for 7 days up to 60 days and the relationship between elevatedheart rate and mortality during the first 7 days and 60th day were assessed.Results: After adjustments for confounding factors, although there was no difference in mean heart rate between either groups of alive and expired patients, however, we have found a relative correlation between 60th day mortality rate and resting heart rate (P=0.07.Conclusion: Heart rate can be a prognostic factor for estimating mortality rate in brain injury patients along with APACHE II and SOFA scores in patients with brain injury.Keywords: Heart rate, APACHE II score, SOFA score, GCS score, Head injury

  20. Utility of a novel biofeedback device for within-breath modulation of heart rate in rats: a quantitative comparison of vagus nerve versus right atrial pacing.

    Directory of Open Access Journals (Sweden)

    Erin Louise O'Callaghan

    2016-02-01

    Full Text Available In an emerging bioelectronics era, there is a clinical need for physiological devices incorporating biofeedback that permits natural and demand-dependent control in real time. Here, we describe a novel device termed a central pattern generator (CPG that uses cutting edge analogue circuitry producing temporally controlled, electrical stimulus outputs based on the real time integration of physiological feedback. Motivated by the fact that respiratory sinus arrhythmia (RSA, which is the cyclical changes in heart rate every breath, is an essential component of heart rate variability (an indicator of cardiac health, we have explored the versatility and efficiency of the CPG for producing respiratory modulation of heart rate in anaesthetised, spontaneously breathing rats. Diaphragmatic electromyographic activity was used as the input to the device and its output connected to either the right cervical vagus nerve or the right atrium for pacing heart rate. We found that the CPG could induce respiratory related heart rate modulation that closely mimicked RSA. Whether connected to the vagus nerve or right atrium, the versatility of the device was demonstrated by permitting: (i heart rate modulation in any phase of the respiratory cycle, (ii control of the magnitude of heart rate modulation and (iii instant adaptation to changes in respiratory frequency. Vagal nerve pacing was only possible following transection of the nerve limiting its effective use chronically. Pacing via the right atrium permitted better flexibility and control of heart rate above its intrinsic level. This investigation now lays the foundation for future studies using this biofeedback technology permitting closer analysis of both the function and dysfunction of RSA.

  1. NUMERIC ANALYSIS OF HEART-RATE VARIATION IN INTRAUTERINE GROWTH RETARDED FETUSES - A LONGITUDINAL-STUDY

    NARCIS (Netherlands)

    SNIJDERS, RJM; RIBBERT, LSM; VISSER, GHA; MULDER, EJH

    OBJECTIVE: We attempted to determine changes occurring with time in fetal heart rate and its variation in fetuses with intrauterine growth retardation in whom late antepartum fetal heart rate decelerations eventually develop. STUDY DESIGN: Thirteen fetuses with intrauterine growth retardation were

  2. Elevated resting heart rate, physical fitness and all-cause mortality

    DEFF Research Database (Denmark)

    Jensen, Magnus Thorsten; Suadicani, Poul; Hein, Hans Ole

    2013-01-01

    To examine whether elevated resting heart rate (RHR) is an independent risk factor for mortality or a mere marker of physical fitness (VO2Max).......To examine whether elevated resting heart rate (RHR) is an independent risk factor for mortality or a mere marker of physical fitness (VO2Max)....

  3. Identification of heart rate-associated loci and their effects on cardiac conduction and rhythm disorders

    NARCIS (Netherlands)

    den Hoed, M.A.H.; Eijgelsheim, M.; Esko, T.; Brundel, B.J.; Peal, D.S.; Evans, D.M.; Nolte, I.M.; Segrè, A.V.; Holm, H.; Handsaker, R.E.; Westra, H.J.; Johnson, T.; Isaacs, A.; Yang, L.; Lundby, A.; Zhao, J.H.; Kim, Y.J.; Go, M.J.; Almgren, P.; Bochud, M.; Boucher, G.; Cornelis, M.C.; Gudbjartsson, D.F.; Hadley, D.; van der Harst, P.; Hayward, C.; den Heijer, M.; Igl, W.; Jackson, A.U.; Kutalik, Z.; Luan, J.; Kemp, J.P.; Kristiansson, K.; Ladenvall, C.; Lorentzon, M.; Montasser, M.E.; Njajou, O.T.; O'Reilly, P.F.; Padmanabhan, S.; St Pourcain, B.; Rankinen, T.; Salo, P.; Tanaka, T.; Timpson, N.J.; Vitart, V.; Waite, L.; Wheeler, W.; Zhang, W.; Draisma, H.H.M.; Feitosa, M.F.; Kerr, K.F.; Lind, P.A.; Mihailov, E.; Onland-Moret, N.C.; Song, C.; Weedon, M.N.; Xie, W.; Yengo, L.; Absher, D.; Albert, C.M.; Alonso, A.; Arking, D.E.; de Bakker, P.I.; Balkau, B.; Barlassina, C.; Benaglio, P.; Bis, J.C.; Bouatia-Naji, N.; Brage, S.; Chanock, S.J.; Chines, P.S.; Chung, M.; Darbar, D.; Dina, C.; Dörr, M.; Elliott, P.; Felix, S.B.; Fischer, K.; Fuchsberger, C.; de Geus, E.J.C.; Goyette, P.; Gudnason, V.; Harris, T.B.; Hartikainen, A.L.; Havulinna, A.S.; Heckbert, S.R.; Hicks, A.A.; Hofman, A.; Holewijn, S.; Hoogstra-Berends, F.; Hottenga, J.J.; Jensen, M.K.; Johansson, A.; Junttila, J.; Kääb, S.; Kanon, B.; Ketkar, S.; Khaw, K.T.; Knowles, J.W.; Kooner, A.S.; Kors, J.A.; Kumari, M.; Milani, L.; Laiho, P.; Lakatta, E.G.; Langenberg, C.; Leusink, M.; Liu, Y.; Luben, R.N.; Lunetta, K.L.; Lynch, S.N.; Markus, M.R.; Marques-Vidal, P.; Mateo Leach, I.; McArdle, W.L.; McCarroll, S.A.; Medland, S.E.; Miller, K.A.; Montgomery, G.W.; Morrison, A.C.; Müller-Nurasyid, M.; Navarro, P.; Nelis, M.; O'Connell, J.R.; O'Donnell, C.J.; Ong, K.K.; Newman, A.B.; Peters, A.; Polasek, O.; Pouta, A.; Pramstaller, P.P.; Psaty, B.M.; Rao, D.C.; Ring, S.M.; Rossin, E.J.; Rudan, D.; Sanna, S.; Scott, R.A.; Sehmi, J.S.; Sharp, S.; Shin, J.T.; Singleton, A.B.; Smith, A.V.; Soranzo, N.; Spector, T.D.; Stewart, C.; Stringham, H.M.; Tarasov, K.V.; Uitterlinden, A.G.; Vandenput, L.; Hwang, S.J.; Whitfield, J.B.; Wijmenga, C.; Wild, S.H.; Willemsen, G.; Wilson, J.F.; Witteman, J.C.; Wong, A.; Wong, Q.; Jamshidi, Y.; Zitting, P.; Boer, J.M.; Boomsma, D.I.; Borecki, I.B.; van Duijn, C.M.; Ekelund, U.; Forouhi, N.G.; Froguel, P.; Hingorani, A.D.; Ingelsson, E.; Kivimaki, M.; Kronmal, R.A.; Kuh, D; Lind, L.; Martin, N.G.; Oostra, B.A.; Pedersen, N.L.; Quertermous, T.; Rotter, J.I.; van der Schouw, Y.T.; Verschuren, W.M.; Walker, M.; Albanes, D.; Arnar, D.O.; Assimes, T.L.; Bandinelli, S.; Boehnke, M.; de Boer, R.A.; Bouchard, C.; Caulfield, W.L.; Chambers, J.C.; Curhan, G.; Cusi, D.; Eriksson, J.; Ferrucci, L.; van Gilst, W.H.; Glorioso, N.; de Graaf, J.; Groop, L.; Gyllensten, U.; Hsueh, W.C.; Hu, F.B.; Huikuri, H.V.; Hunter, D.J.; Iribarren, C.; Isomaa, B.; Järvelin, M.R.; Jula, A.; Kähönen, M.; Kiemeney, L.A.; van der Klauw, M.M.; Kooner, J.S.; Kraft, P.; Iacoviello, L.; Lehtimäki, T.; Lokki, M.L.; Mitchell, B.D.; Navis, G.; Nieminen, M.S.; Ohlsson, C.; Poulter, N.R.; Qi, L.; Raitakari, O.T.; Rimm, E.B.; Rioux, J.D.; Rizzi, F.; Rudan, I.; Salomaa, V.; Sever, P.S.; Shields, D.C.; Shuldiner, A.R.; Sinisalo, J.; Stanton, A.V.; Stolk, R.P.; Strachan, D.P.; Tardif, J.C.; Thorsteinsdottir, U.; Tuomilehto, J.; van Veldhuisen, D.J.; Virtamo, J.; Viikari, J.; Vollenweider, P.; Waeber, G.; Widen, E.; Cho, Y.S.; Olsen, J.V.; Visscher, P.M.; Willer, C.J.; Franke, L; Erdmann, J.; Thompson, J.R.; Pfeufer, A.; Sotoodehnia, N.; Newton-Cheh, C.; Ellinor, P.T.; Stricker, B.H.C.; Metspalu, A.; Perola, M.; Beckmann, J.S.; Smith, G.D.; Stefansson, K.; Wareham, N.J.; Munroe, P.B.; Sibon, O.C.M.; Milan, D.J.; Snieder, H.; Samani, N.J.; Loos, R.J.

    2013-01-01

    Elevated resting heart rate is associated with greater risk of cardiovascular disease and mortality. In a 2-stage meta-analysis of genome-wide association studies in up to 181,171 individuals, we identified 14 new loci associated with heart rate and confirmed associations with all 7 previously

  4. Antepartum sinusoidal and decelerative heart-rate patterns in rh disease

    NARCIS (Netherlands)

    Visser, G. H. A.

    1982-01-01

    A review was made of the data on 42 cases of Rh disease that resulted in the birth of a liver infant after 33 weeks' gestation. On 12 occasions, antepartum monitoring of fetal heart rate (FHR) showed a sinusoidal and/or decelerative heart rate pattern. All 12 infants were anemic at birth; only one

  5. Modulations of Heart Rate, ECG, and Cardio-Respiratory Coupling Observed in Polysomnography

    Directory of Open Access Journals (Sweden)

    Thomas Penzel

    2016-10-01

    Full Text Available The cardiac component of cardio-respiratory polysomnography is covered by ECG and heart rate recordings. However their evaluation is often underrepresented in summarizing reports. As complements to EEG, EOG, and EMG, these signals provide diagnostic information for autonomic nervous activity during sleep. This review presents major methodological developments in sleep research regarding heart rate, ECG and cardio-respiratory couplings in a chronological (historical sequence. It presents physiological and pathophysiological insights related to sleep medicine obtained by new technical developments. Recorded nocturnal ECG facilitates conventional heart rate variability analysis, studies of cyclical variations of heart rate, and analysis of ECG waveform. In healthy adults, the autonomous nervous system is regulated in totally different ways during wakefulness, slow-wave sleep, and REM sleep. Analysis of beat-to-beat heart-rate variations with statistical methods enables us to estimate sleep stages based on the differences in autonomic nervous system regulation. Furthermore, up to some degree, it is possible to track transitions from wakefulness to sleep by analysis of heart-rate variations. ECG and heart rate analysis allow assessment of selected sleep disorders as well. Sleep disordered breathing can be detected reliably by studying cyclical variation of heart rate combined with respiration-modulated changes in ECG morphology (amplitude of R wave and T wave.

  6. Association between vasomotor hot flashes and heart rate variability in recently postmenopausal women.

    Science.gov (United States)

    Hoikkala, Hanna; Haapalahti, Petri; Viitasalo, Matti; Väänänen, Heikki; Sovijärvi, Anssi R A; Ylikorkala, Olavi; Mikkola, Tomi S

    2010-03-01

    The aim of this study was to investigate whether cardiovascular autonomic reactivity and risk profile are associated with the frequency and severity of hot flashes in recently postmenopausal women. A total of 150 postmenopausal women with varying degrees of severity of hot flashes (none, mild, moderate, or severe) underwent 24-hour electrocardiographic recording. The function of the autonomic nervous system was assessed via heart rate variability in time and frequency domains. The effects of hot flashes on cardiac autonomic function were studied by assessing heart rate variability in the presence and absence of symptoms. There were no differences in mean heart rate, heart rate extremes, or total number of ectopic beats between women without and women with mild, moderate, or severe hot flashes. However, most women (14/17, 82%) with frequent ventricular ectopic beats and all women with ventricular runs belonged to the symptomatic groups. Although there were no differences in 24-hour or nighttime heart rate variability between the study groups, the very-low-frequency spectral component of heart rate variability increased by 72% (P hot flash period compared with the control period and was accompanied by an increase in heart rate (3%; P hot flashes in recently postmenopausal women. However, during a hot flash episode, there were signs of altered autonomic control of heart rate, which may be involved in the regulatory mechanisms of hot flashes.

  7. Identification of heart rate-associated loci and their effects on cardiac conduction and rhythm disorders

    DEFF Research Database (Denmark)

    den Hoed, Marcel; Eijgelsheim, Mark; Esko, Tõnu

    2013-01-01

    Elevated resting heart rate is associated with greater risk of cardiovascular disease and mortality. In a 2-stage meta-analysis of genome-wide association studies in up to 181,171 individuals, we identified 14 new loci associated with heart rate and confirmed associations with all 7 previously es...

  8. Variation in heart rate during submaximal exercise: Implications for monitoring training : Implications for monitoring training

    NARCIS (Netherlands)

    Lamberts, R.P.; Lemmink, K.A.P.M.; Durandt, J.J.; Lambert, M.I.

    2004-01-01

    A change in heart rate at a controlled submaximal exercise intensity is used as a marker of training status. However, the standard error of measurement has not been studied systematically, and therefore a change in heart rate, which can be considered relevant, has not been determined. Forty-four

  9. Problem behavior and heart rate reactivity in adopted adolescents: Longitudinal and concurrent relations.

    NARCIS (Netherlands)

    Bimmel, N.; van IJzendoorn, M.H.; Bakermans-Kranenburg, M.J.; Juffer, F.; de Geus, E.J.C.

    2008-01-01

    The present longitudinal study examined resting heart rate and heart rate variability and reactivity to a stressful gambling task in adopted adolescents with aggressive, delinquent, or internalizing behavior problems and adopted adolescents without behavior problems (total N=151). Early-onset

  10. The Influence of Motor Impairment on Autonomic Heart Rate Modulation among Children with Cerebral Palsy

    Science.gov (United States)

    Zamuner, Antonio Roberto; Cunha, Andrea Baraldi; da Silva, Ester; Negri, Ana Paola; Tudella, Eloisa; Moreno, Marlene Aparecida

    2011-01-01

    The study of heart rate variability is an important tool for a noninvasive evaluation of the neurocardiac integrity. The present study aims to evaluate the autonomic heart rate modulation in supine and standing positions in 12 children diagnosed with cerebral palsy and 16 children with typical motor development (control group), as well as to…

  11. Resemblances of Parents and Twins in Sport Participation and Heart Rate

    NARCIS (Netherlands)

    Boomsma, D.I.; van den Bree, M.B.; Orlebeke, J.F.; Molenaar, P.C.M.

    1989-01-01

    A model to analyze resemblances of twins and parents using LISREL is outlined and applied to sports participation and heart-rate data. Sports participation and heart rate were measured in 44 monozygotic and 46 dizygotic adolescent twin pairs and in their parents. Genetic factors influence variation

  12. Skeletal muscle signaling and the heart rate and blood pressure response to exercise

    DEFF Research Database (Denmark)

    Mortensen, Stefan P; Svendsen, Jesper H; Ersbøll, Mads

    2013-01-01

    -extensor training and 2 weeks of deconditioning of the other leg (leg cast). Hemodynamics and muscle interstitial nucleotides were determined during exercise with the (1) deconditioned leg, (2) trained leg, and (3) trained leg with atrial pacing to the heart rate obtained with the deconditioned leg. Heart rate...

  13. Autonomic heart-rate control in response to standing in toxemic and normotensive primigravid pregnancies

    NARCIS (Netherlands)

    WJ Jaspers; PA de Jong; PJ Kurver; MD E.J.M. Wouters

    1984-01-01

    Heart-rate changes after transition from a supine to a standing posture were measured in 12 hypertensive and 12 normotensive primigravid women, in their last trimester of gestation. The subjects beat-to-beat heart-rate (HR) changes were recorded on both an ordinary cardiotocograph and on magnetic

  14. Heart rate variability and the metabolic syndrome: a systematic review of the literature.

    Science.gov (United States)

    Stuckey, Melanie I; Tulppo, Mikko P; Kiviniemi, Antti M; Petrella, Robert J

    2014-11-01

    A number of cross-sectional studies have examined associations between heart rate variability and metabolic syndrome, but differences in study populations, data collection and analysis methodologies make synthesis difficult. The purpose of this study was to systematically review published primary research examining associations between heart rate variability and metabolic syndrome or its individual risk factors. A systematic literature search of PubMed and EMBASE was conducted to identify relevant articles published from January 1999 to December 2012. Studies were included if they examined associations between heart rate variability analysed by standard protocols and metabolic syndrome risk factors according to published definitions. All papers were scored with a modified Downs and Black instrument, and data were extracted. Fourteen studies were included. Heart rate variability generally was reduced in women with metabolic syndrome compared to those without, while results in men were inconsistent. Time and frequency domain heart rate variability parameters were associated with individual metabolic syndrome risk factors, though sex differences exist. Only two studies considered nonlinear and Poincaré plot heart rate variability parameters, which were reduced in metabolic syndrome. Heart rate variability is altered differently in men and women with metabolic syndrome. Future studies should follow consistent heart rate variability analysis protocols and metabolic syndrome definitions and include more comprehensive analyses to investigate potential mechanisms. Copyright © 2014 John Wiley & Sons, Ltd.

  15. Identification of heart rate-associated loci and their effects on cardiac conduction and rhythm disorders

    NARCIS (Netherlands)

    den Hoed, Marcel; Eijgelsheim, Mark; Esko, Tonu; Brundel, Bianca J. J. M.; Peal, David S.; Evans, David M.; Nolte, Ilja M.; Segre, Ayellet V.; Holm, Hilma; Handsaker, Robert E.; Westra, Harm-Jan; Johnson, Toby; Isaacs, Aaron; Yang, Jian; Lundby, Alicia; Zhao, Jing Hua; Kim, Young Jin; Go, Min Jin; Almgren, Peter; Bochud, Murielle; Boucher, Gabrielle; Cornelis, Marilyn C.; Gudbjartsson, Daniel; Hadley, David; van der Harst, Pim; Hayward, Caroline; den Heijer, Martin; Igl, Wilmar; Jackson, Anne U.; Kutalik, Zoltan; Luan, Jian'an; Kemp, John P.; Kristiansson, Kati; Ladenvall, Claes; Lorentzon, Mattias; Montasser, May E.; Njajou, Omer T.; O'Reilly, Paul F.; Padmanabhan, Sandosh; Pourcain, Beate St.; Rankinen, Tuomo; Salo, Perttu; Tanaka, Toshiko; Timpson, Nicholas J.; Vitart, Veronique; Waite, Lindsay; Wheeler, William; Zhang, Weihua; Draisma, Harmen H. M.; Feitosa, Mary F.; Kerr, Kathleen F.; Lind, Penelope A.; Mihailov, Evelin; Onland-Moret, N. Charlotte; Song, Ci; Weedon, Michael N.; Xie, Weijia; Yengo, Loic; Absher, Devin; Albert, Christine M.; Alonso, Alvaro; Arking, Dan E.; de Bakker, Paul I. W.; Balkau, Beverley; Barlassina, Cristina; Benaglio, Paola; Bis, Joshua C.; Bouatia-Naji, Nabila; Brage, Soren; Chanock, Stephen J.; Chines, Peter S.; Chung, Mina; Darbar, Dawood; Dina, Christian; Doerr, Marcus; Elliott, Paul; Felix, Stephan B.; Fischer, Krista; Fuchsberger, Christian; de Geus, Eco J. C.; Goyette, Philippe; Gudnason, Vilmundur; Harris, Tamara B.; Hartikainen, Anna-Liisa; Havulinna, Aki S.; Heckbert, Susan R.; Hicks, Andrew A.; Hofman, Albert; Holewijn, Suzanne; Hoogstra-Berends, Femke; Hottenga, Jouke-Jan; Jensen, Majken K.; Johansson, Asa; Junttila, Juhani; Kaeaeb, Stefan; Kanon, Bart; Ketkar, Shamika; Khaw, Kay-Tee; Knowles, Joshua W.; Kooner, Angrad S.; Kors, Jan A.; Kumari, Meena; Milani, Lili; Laiho, Paeivi; Lakatta, Edward G.; Langenberg, Claudia; Leusink, Maarten; Liu, Yongmei; Luben, Robert N.; Lunetta, Kathryn L.; Lynch, Stacey N.; Markus, Marcello R. P.; Marques-Vidal, Pedro; Mateo Leach, Irene; McArdle, Wendy L.; McCarroll, Steven A.; Medland, Sarah E.; Miller, Kathryn A.; Montgomery, Grant W.; Morrison, Alanna C.; Mueller-Nurasyid, Martina; Navarro, Pau; Nelis, Mari; O'Connell, Jeffrey R.; O'Donnell, Christopher J.; Ong, Ken K.; Newman, Anne B.; Peters, Annette; Polasek, Ozren; Pouta, Anneli; Pramstaller, Peter P.; Psaty, Bruce M.; Rao, Dabeeru C.; Ring, Susan M.; Rossin, Elizabeth J.; Rudan, Diana; Sanna, Serena; Scott, Robert A.; Sehmi, Jaban S.; Sharp, Stephen; Shin, Jordan T.; Singleton, Andrew B.; Smith, Albert V.; Soranzo, Nicole; Spector, Tim D.; Stewart, Chip; Stringham, Heather M.; Tarasov, Kirill V.; Uitterlinden, Andre G.; Vandenput, Liesbeth; Hwang, Shih-Jen; Whitfield, John B.; Wijmenga, Cisca; Wild, Sarah H.; Willemsen, Gonneke; Wilson, James F.; Witteman, Jacqueline C. M.; Wong, Andrew; Wong, Quenna; Jamshidi, Yalda; Zitting, Paavo; Boer, Jolanda M. A.; Boomsma, Dorret I.; Borecki, Ingrid B.; van Duijn, Cornelia M.; Ekelund, Ulf; Forouhi, Nita G.; Froguel, Philippe; Hingorani, Aroon; Ingelsson, Erik; Kivimaki, Mika; Kronmal, Richard A.; Kuh, Diana; Lind, Lars; Martin, Nicholas G.; Oostra, Ben A.; Pedersen, Nancy L.; Quertermous, Thomas; Rotter, Jerome I.; van der Schouw, Yvonne T.; Verschuren, W. M. Monique; Walker, Mark; Albanes, Demetrius; Arnar, David O.; Assimes, Themistocles L.; Bandinelli, Stefania; Boehnke, Michael; de Boer, Rudolf A.; Bouchard, Claude; Caulfield, W. L. Mark; Chambers, John C.; Curhan, Gary; Cusi, Daniele; Eriksson, Johan; Ferrucci, Luigi; van Gilst, Wiek H.; Glorioso, Nicola; de Graaf, Jacqueline; Groop, Leif; Gyllensten, Ulf; Hsueh, Wen-Chi; Hu, Frank B.; Huikuri, Heikki V.; Hunter, David J.; Iribarren, Carlos; Isomaa, Bo; Jarvelin, Marjo-Riitta; Jula, Antti; Kahonen, Mika; Kiemeney, Lambertus A.; van der Klauw, Melanie M.; Kooner, Jaspal S.; Kraft, Peter; Iacoviello, Licia; Lehtimaki, Terho; Lokki, Marja-Liisa L.; Mitchell, Braxton D.; Navis, Gerjan; Nieminen, Markku S.; Ohlsson, Claes; Poulter, Neil R.; Qi, Lu; Raitakari, Olli T.; Rimm, Eric B.; Rioux, John D.; Rizzi, Federica; Rudan, Igor; Salomaa, Veikko; Sever, Peter S.; Shields, Denis C.; Shuldiner, Alan R.; Sinisalo, Juha; Stanton, Alice V.; Stolk, Ronald P.; Strachan, David P.; Tardif, Jean-Claude; Thorsteinsdottir, Unnur; Tuomilehto, Jaako; van Veldhuisen, Dirk J.; Virtamo, Jarmo; Viikari, Jorma; Vollenweider, Peter; Waeber, Gerard; Widen, Elisabeth; Cho, Yoon Shin; Olsen, Jesper V.; Visscher, Peter M.; Willer, Cristen; Franke, Lude; Erdmann, Jeanette; Thompson, John R.; Pfeufer, Arne; Sotoodehnia, Nona; Newton-Cheh, Christopher; Ellinor, Patrick T.; Stricker, Bruno H. Ch; Metspalu, Andres; Perola, Markus; Beckmann, Jacques S.; Smith, George Davey; Stefansson, Kari; Wareham, Nicholas J.; Munroe, Patricia B.; Sibon, Ody C. M.; Milan, David J.; Snieder, Harold; Samani, Nilesh J.; Loos, Ruth J. F.

    Elevated resting heart rate is associated with greater risk of cardiovascular disease and mortality. In a 2-stage meta-analysis of genome-wide association studies in up to 181,171 individuals, we identified 14 new loci associated with heart rate and confirmed associations with all 7 previously

  16. Heart Rates of Elementary Physical Education Students during the Dancing Classrooms Program

    Science.gov (United States)

    Nelson, Larry; Evans, Melissa; Guess, Wendy; Morris, Mary; Olson, Terry; Buckwalter, John

    2011-01-01

    We examined how different types of dance activities, along with their duration, influenced heart rate responses among fifth-grade physical education students (N = 96) who participated in the Dancing Classrooms program. Results indicated that the overall Dancing Classrooms program elicits a moderate cardiovascular heart rate response (M = 124.4…

  17. Decreased nighttime heart rate variability is associated with increased stroke risk

    DEFF Research Database (Denmark)

    Binici, Zeynep; Mouridsen, Mette Rauhe; Køber, Lars

    2011-01-01

    Prediction of stroke in healthy individuals is challenging and there is a diurnal variation of stroke onset. We hypothesized that heart rate variability with a focus on nighttime heart rate variability will predict the risk of stroke in apparently healthy middle-age and elderly subjects....

  18. Electroencephalogram and Heart Rate Regulation to Familiar and Unfamiliar People in Children with Autism Spectrum Disorders

    Science.gov (United States)

    Van Hecke, Amy Vaughan; Lebow, Jocelyn; Bal, Elgiz; Lamb, Damon; Harden, Emily; Kramer, Alexis; Denver, John; Bazhenova, Olga; Porges, Stephen W.

    2009-01-01

    Few studies have examined whether familiarity of partner affects social responses in children with autism. This study investigated heart rate regulation (respiratory sinus arrhythmia [RSA]: The myelinated vagus nerve's regulation of heart rate) and temporal-parietal electroencephalogram (EEG) activity while nineteen 8- to 12-year-old children with…

  19. Reproducibility of heart rate variability and baroreflex sensitivity measurements in children

    NARCIS (Netherlands)

    Dietrich, Andrea; Rosmalen, Judith G. M.; Althaus, Monika; van Roon, Arie M.; Mulder, Lambertus J. M.; Minderaa, Ruud B.; Oldehinkel, Albertine J.; Riese, Harriette

    Despite their extensive use, the reproducibility of cardiac autonomic measurements in children is not well-known. We investigated the reproducibility of short-term continuous measurements of heart rate (HR), heart rate variability (HRV, time and frequency domain), and spontaneous baroreflex

  20. Modulations of Heart Rate, ECG, and Cardio-Respiratory Coupling Observed in Polysomnography.

    Science.gov (United States)

    Penzel, Thomas; Kantelhardt, Jan W; Bartsch, Ronny P; Riedl, Maik; Kraemer, Jan F; Wessel, Niels; Garcia, Carmen; Glos, Martin; Fietze, Ingo; Schöbel, Christoph

    2016-01-01

    The cardiac component of cardio-respiratory polysomnography is covered by ECG and heart rate recordings. However, their evaluation is often underrepresented in summarizing reports. As complements to EEG, EOG, and EMG, these signals provide diagnostic information for autonomic nervous activity during sleep. This review presents major methodological developments in sleep research regarding heart rate, ECG, and cardio-respiratory couplings in a chronological (historical) sequence. It presents physiological and pathophysiological insights related to sleep medicine obtained by new technical developments. Recorded nocturnal ECG facilitates conventional heart rate variability (HRV) analysis, studies of cyclical variations of heart rate, and analysis of ECG waveform. In healthy adults, the autonomous nervous system is regulated in totally different ways during wakefulness, slow-wave sleep, and REM sleep. Analysis of beat-to-beat heart-rate variations with statistical methods enables us to estimate sleep stages based on the differences in autonomic nervous system regulation. Furthermore, up to some degree, it is possible to track transitions from wakefulness to sleep by analysis of heart-rate variations. ECG and heart rate analysis allow assessment of selected sleep disorders as well. Sleep disordered breathing can be detected reliably by studying cyclical variation of heart rate combined with respiration-modulated changes in ECG morphology (amplitude of R wave and T wave).

  1. Neighborhood blight, stress, and health: a walking trial of urban greening and ambulatory heart rate

    Science.gov (United States)

    Eugenia C. South; Michelle C. Kondo; Rose A. Cheney; Charles C. Branas

    2015-01-01

    We measured dynamic stress responses using ambulatory heart rate monitoring as participants in Philadelphia, Pennsylvania walked past vacant lots before and after a greening remediation treatment of randomly selected lots. Being in view of a greened vacant lot decreased heart rate significantly more than did being in view of a nongreened vacant lot or not in view of...

  2. Heart Rate Level and Antisocial Behavior in Children and Adolescents: A Meta-Analysis

    Science.gov (United States)

    Ortiz, Jame; Raine, Adrian

    2004-01-01

    Objective: To assess whether antisocial children are characterized by low heart rate. Method: A meta-analysis was conducted on 45 independent effect sizes of the resting heart rate-antisocial behavior relationship obtained from 40 studies meeting inclusion and exclusion criteria. Studies were conducted between 1971 to 2002 using a total of 5,868…

  3. Using Heart Rate Monitors in Research on Fitness Levels of Children in Physical Education.

    Science.gov (United States)

    Strand, Brad; Reeder, Steve

    1993-01-01

    Demonstrates the use of heart rate monitors (HRMs) in fitness research and examines heart rate intensity levels of middle school students while they participated in a variety of physical education activities throughout a school year. Research shows the HRM has considerable potential in assessing fitness achievements in school-age children. (GLR)

  4. External physical stimulation of the human-fetus during episodes of low heart-rate variation

    NARCIS (Netherlands)

    Visser, G. H. A.; ZEELENBERG, HJ; DEVRIES, JIP; DAWES, GS

    1983-01-01

    The effect of shaking the fetus through the maternal abdomen during episodes of low (nonreactive) fetal heart rate variation was studied in 10 healthy nulliparous women near term. Heart rate monitoring from an abdominal electrocardiogram was combined with real-time scanning for body movements and

  5. Middle School Student's Heart Rates during Different Curricular Activities in Physical Education

    Science.gov (United States)

    Gao, Zan; Hannon, James C.; Carson, Russell L.

    2009-01-01

    The purpose of this study was to determine if students' heart rate outcomes in physical education varied as a function of activity and grade. A total of 146 sixth to eighth graders participated in different activities (i.e., walking/jogging, line dancing, soccer, and catch ball). Their average heart rate (AHR) and percentage of time in and above…

  6. Eurythmy therapy increases specific oscillations of heart rate variability.

    Science.gov (United States)

    Edelhäuser, Friedrich; Minnerop, Antje; Trapp, Barbara; Büssing, Arndt; Cysarz, Dirk

    2015-06-06

    Mind-body therapies are beneficial for several diseases (e.g. chronic pain, arterial hypertension, mood disorders). Eurythmy therapy (EYT) is a mind-body therapy from Anthroposophic Medicine. In each EYT exercise a short sequence of body movements and simultaneous guided imagery is repeated several times. In this study, the simultaneous effects of two different EYT exercises on cardiac autonomic regulation as assessed by spectral analysis of heart rate variability (HRV) were investigated. Twenty healthy subjects (age: 29.1 ± 9.3 years, 13 female) performed two different EYT exercises (EYT-A and EYT-B) for 8 min. Each EYT exercise was compared against two matched control exercises: control exercise 1 (CE1-A and CE1-B) consisted of a repetition of the body movements of the EYT exercise but without guided imagery, control exercise 2 consisted of walking on the spot (CE2-A and CE2-B). Spectral power of HRV during each exercise was quantified on the basis of Holter ECG recordings. During EYT-A the frequency of the peak oscillation in the very low frequency (VLF) band matched the repetition rate of the sequence of body movements (0.02 Hz). Low frequency (LF) oscillations were augmented when compared to the control exercises (EYT-A: 7.31 ± 0.84, CE1-A: 6.98 ± 0.90, CE2-A: 6.52 ± 0.87 ln ms(2), p exercises (EYT-B: 9.32 ± 0.82, CE1-B: 6.31 ± 0.75, CE2-B: 6.04 ± 0.80 ln ms(2), p exercises clearly affected cardiac autonomic regulation in a rhythmic manner according to the stimulus of the specific body movements of each EYT exercise. These results offer a physiological basis to develop a rationale for specific clinical indications of these EYT exercises such as stress reduction or prevention of hypertension. DRKS00006760 (registered on 10/10/2014, i.e. retrospective registration); view details at http://www.drks.de/DRKS00006760.

  7. Effect of mibefradil on heart rate variability in patients with chronic heart failure

    NARCIS (Netherlands)

    Brouwer, J; de Kam, PJ; Haaksma, J; Crijns, HJGM; van Veldhuisen, DJ

    2000-01-01

    Background: Mibefradil was recently withdrawn from the market because of an unfavorable clinical profile in patients with chronic heart failure. Although drug interactions appear to play a role, other mechanisms such as proarrhythmia and autonomic deterioration could also be relevant. Chronic heart

  8. Mechanoelectric feedback does not contribute to the Frank-Starling relation in the rat and guinea pig heart

    Directory of Open Access Journals (Sweden)

    D Kelly

    2014-12-01

    Full Text Available Mechanoelectric feedback (MEF is the process by which mechanical forces on the myocardium can alter its electrical properties. The effect can be large enough to induce ectopic beats or fibrillation. However, the role of MEF at physiological levels of mechanical stress is not clear. We have investigated alteration in action potential morphology in rat and guinea pig ventricle and in rat atrial tissue at levels of stretch near the plateau of the Frank-Starling curve. Stretch of >100 mm.Hg End Diastolic Left Ventricular Pressure (EDLVP or rapidly applied stretch (EDLVP increased by 25 mm.Hg within 100 ms often triggered ectopic beats in isolated rat and guinea-pig hearts. However, ventricular epicardial monophasic action potentials (MAPs recorded during stretch to EDLVP up to 30 mm. Hg showed no consistent changes in action potential duration (at APD20, APD50 or APD80 in either species. MAP recording detected APD prolongation with very small concentrations of 4-AP (10 μM, confirming the discrimination of the recording technique. In isolated rat atrial strips, no changes in intracellular action potential morphology or membrane potential were seen when stretched to levels producing an optimum increase in contractility. We conclude that alteration in action potential morphology with stretch does not contribute to the Frank-Starling relation in ventricle of rat or guinea-pig isolated heart, or in rat atrial tissue.

  9. Helping from the heart: Voluntary upregulation of heart rate variability predicts altruistic behavior.

    Science.gov (United States)

    Bornemann, Boris; Kok, Bethany E; Böckler, Anne; Singer, Tania

    2016-09-01

    Our various daily activities continually require regulation of our internal state. These regulatory processes covary with changes in High Frequency Heart Rate Variability (HF-HRV), a marker of parasympathetic activity. Specifically, incidental increases in HF-HRV accompany positive social engagement behavior and prosocial action. Little is known about deliberate regulation of HF-HRV and the role of voluntary parasympathetic regulation in prosocial behavior. Here, we present a novel biofeedback task that measures the ability to deliberately increase HF-HRV. In two large samples, we find that a) participants are able to voluntarily upregulate HF-HRV, and b) variation in this ability predicts individual differences in altruistic prosocial behavior, but not non-altruistic forms of prosociality, assessed through 14 different measures. Our findings suggest that self-induction of parasympathetic states is involved in altruistic action. The biofeedback task may provide a measure of deliberate parasympathetic regulation, with implications for the study of attention, emotion, and social behavior. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Resting heart rate and the risk of hypertension and heart failure: a dose-response meta-analysis of prospective studies.

    Science.gov (United States)

    Shi, Yuanyuan; Zhou, Wen; Liu, Xuejiao; Ping, Zhiguang; Li, Yu-Qian; Wang, Chongjian; Lu, Jie; Mao, Zhen-Xing; Zhao, Jingzhi; Yin, Lei; Zhang, Dongdong; Li, Linlin

    2017-11-25

    Studies on the relationship of resting heart rate to the risks of hypertension and heart failure have been inconsistent, and the question as to whether there is a linear association between them is unanswered. To evaluate this possible relationship, we carried out a dose-response meta-analysis of studies that looked at risks associated with resting heart rate and hypertension or heart failure. We searched PubMed, Embase, CNKI and WanFang databases for articles published before 15 June 2017. A random-effect model was used to pool relative risks and 95% confidence intervals. Restricted cubic spline analysis was used to model the resting heart rate-hypertension and heart failure risk association. We identified 13 and 17 cohort studies for hypertension and heart failure, respectively. The risk for each disease, respectively, increased by 11% relative risk: 1.11 (95% confidence interval: 1.07-1.15) and 19% relative risk: 1.19 (95% confidence interval: 1.13-1.25) for each 10 beats-per-minute increment in resting heart rate. The relationship between resting heart rate and hypertension or heart failure was consistent in most subgroup analyses except for gender subgroups, with no significant association observed in the women subgroup. The results provide no evidence of a nonlinear association of elevated resting heart rate with hypertension and heart failure risk. Resting heart rate shows a linear positive association with the incidence of hypertension and heart failure.

  11. Reduction of Heart Rate by Omega-3 Fatty Acids and the Potential Underlying Mechanisms

    Directory of Open Access Journals (Sweden)

    Jing Xuan Kang

    2012-10-01

    Full Text Available An elevated resting heart rate is one of the strongest predictors of cardiovascular mortality and is independently associated with sudden cardiac death (SCD. Agents capable of reducing heart rate without significant side effects are therefore of particular interest for the prevention of SCD. Recent human and animal studies have shown that omega-3 fatty acids can reduce heart rate. Our work has shown that omega-3 fatty acids significantly reduce membrane electrical excitability of the cardiac myocyte by lowering its resting membrane potential and the duration of the refractory period through inhibition of ion channels. We propose that these actions may be the underlying mechanisms for the omega-3 fatty acid-induced reduction of heart rate observed in both humans and animals. The heart rate-lowering capability of omega-3 fatty acids may contribute to their preventive effect against SCD.

  12. Dynamics of heart rate parameters in students with various personal anxiety levels during computerized testing.

    Science.gov (United States)

    Dzhebrailova, T D; Sulejmanova, R G

    2012-09-01

    Students with low level of initial (pre-test) personal anxiety demonstrated a high level of modulating effects on the heart rate in all basic frequency ranges (VLF, LF, and HF) resulting in a greater total power of heart rate variability spectrum compared to students with high personal anxiety. The peculiarities of dynamics of heart rate variability were revealed during a real learning task, which correlated with personal anxiety level. In comparison with highly anxious students, the low-anxious group demonstrated more pronounced drop in the power of all ranges of the heart rate variability spectrum during testing followed by restoration of these power indices to initial levels after completion of the test. In contrast, the drop of the total power of the heart rate variability spectrum and in the power of its individual components persisted in students with high anxiety level even after the end of the testing.

  13. Selective attenuation of norepinephrine release and stress-induced heart rate increase by partial adenosine A1 agonism.

    Directory of Open Access Journals (Sweden)

    Lorenz Bott-Flügel

    Full Text Available The release of the neurotransmitter norepinephrine (NE is modulated by presynaptic adenosine receptors. In the present study we investigated the effect of a partial activation of this feedback mechanism. We hypothesized that partial agonism would have differential effects on NE release in isolated hearts as well as on heart rate in vivo depending on the genetic background and baseline sympathetic activity. In isolated perfused hearts of Wistar and Spontaneously Hypertensive Rats (SHR, NE release was induced by electrical stimulation under control conditions (S1, and with capadenoson 6 · 10(-8 M (30 µg/l, 6 · 10(-7 M (300 µg/l or 2-chloro-N(6-cyclopentyladenosine (CCPA 10(-6 M (S2. Under control conditions (S1, NE release was significantly higher in SHR hearts compared to Wistar (766+/-87 pmol/g vs. 173+/-18 pmol/g, p<0.01. Capadenoson led to a concentration-dependent decrease of the stimulation-induced NE release in SHR (S2/S1  =  0.90 ± 0.08 with capadenoson 6 · 10(-8 M, 0.54 ± 0.02 with 6 · 10(-7 M, but not in Wistar hearts (S2/S1  =  1.05 ± 0.12 with 6 · 10(-8 M, 1.03 ± 0.09 with 6 · 10(-7 M. CCPA reduced NE release to a similar degree in hearts from both strains. In vivo capadenoson did not alter resting heart rate in Wistar rats or SHR. Restraint stress induced a significantly greater increase of heart rate in SHR than in Wistar rats. Capadenoson blunted this stress-induced tachycardia by 45% in SHR, but not in Wistar rats. Using a [(35S]GTPγS assay we demonstrated that capadenoson is a partial agonist compared to the full agonist CCPA (74+/-2% A(1-receptor stimulation. These results suggest that partial adenosine A(1-agonism dampens stress-induced tachycardia selectively in rats susceptible to strong increases in sympathetic activity, most likely due to a presynaptic attenuation of NE release.

  14. Heart rate regulation in diving sea lions: the vagus nerve rules.

    Science.gov (United States)

    Ponganis, Paul J; McDonald, Birgitte I; Tift, Michael S; Williams, Cassondra L

    2017-04-15

    Recent publications have emphasized the potential generation of morbid cardiac arrhythmias secondary to autonomic conflict in diving marine mammals. Such conflict, as typified by cardiovascular responses to cold water immersion in humans, has been proposed to result from exercise-related activation of cardiac sympathetic fibers to increase heart rate, combined with depth-related changes in parasympathetic tone to decrease heart rate. After reviewing the marine mammal literature and evaluating heart rate profiles of diving California sea lions (Zalophus californianus), we present an alternative interpretation of heart rate regulation that de-emphasizes the concept of autonomic conflict and the risk of morbid arrhythmias in marine mammals. We hypothesize that: (1) both the sympathetic cardiac accelerator fibers and the peripheral sympathetic vasomotor fibers are activated during dives even without exercise, and their activities are elevated at the lowest heart rates in a dive when vasoconstriction is maximal, (2) in diving animals, parasympathetic cardiac tone via the vagus nerve dominates over sympathetic cardiac tone during all phases of the dive, thus producing the bradycardia, (3) adjustment in vagal activity, which may be affected by many inputs, including exercise, is the primary regulator of heart rate and heart rate fluctuations during diving, and (4) heart beat fluctuations (benign arrhythmias) are common in marine mammals. Consistent with the literature and with these hypotheses, we believe that the generation of morbid arrhythmias because of exercise or stress during dives is unlikely in marine mammals. © 2017. Published by The Company of Biologists Ltd.

  15. Behavioral correlates of heart rates of free-living Greater White-fronted Geese

    Science.gov (United States)

    Ely, C.R.; Ward, D.H.; Bollinger, K.S.

    1999-01-01

    We simultaneously monitored the heart rate and behavior of nine free-living Greater White-fronted Geese (Anser albifrons) on their wintering grounds in northern California. Heart rates of wild geese were monitored via abdominally-implanted radio transmitters with electrodes that received electrical impulses of the heart and emitted a radio signal with each ventricular contraction. Post-operative birds appeared to behave normally, readily rejoining flocks and flying up to 15 km daily from night-time roost sites to feed in surrounding agricultural fields. Heart rates varied significantly among individuals and among behaviors, and ranged from less than 100 beats per minute (BPM) during resting, to over 400 BPM during flight. Heart rates varied from 80 to 140 BPM during non-strenuous activities such as walking, feeding, and maintenance activities, to about 180 BPM when birds became alert, and over 400 BPM when birds were startled, even if they did not take flight. Postflight heart rate recovery time averaged postures, as heart rates were context-dependent, and were highest in initial encounters among individuals. Instantaneous measures of physiological parameters, such as heart rate, are often better indicators of the degree of response to external stimuli than visual observations and can be used to improve estimates of energy expenditure based solely on activity data.

  16. Clutch effects explain heart rate variation in embryonic frogs (Cave Coqui, Eleutherodactylus cooki).

    Science.gov (United States)

    Burggren, W; Crossley, D; Rogowitz, G; Thompson, D

    2003-01-01

    Few physiological studies to date have focused on whether variation among sibling groups during development can account for often large, intraspecific physiological variation. In this study, we measured heart rate in the direct-developing frog Eleutherodactylus cooki throughout its embryonic development and examined heart rate variation among egg clutches comprising from 10 to 40 eggs. Clutches were collected in the wild in Yubucoa, Puerto Rico, and individual eggs were maintained under equivalent conditions in the lab. Heart rate showed large increases during development, rising from about 40 beats min(-1) in the earliest stages to about 110 beats min(-1) at hatching. The effect of stage (averaged across clutches) was highly significant (P<0.001). However, repeated-measures MANOVA also revealed that there were highly significant effects on heart rate associated with both clutch (variation among clutches averaged across development; P<0.001) and clutch-stage interactions (differences among clutches in the developmental change in heart rate; P<0.0001). These effects and interactions reveal that throughout development, heart rate in siblings is much more similar than in nonsiblings and that sib groups follow different heart rate trajectories during their development. Collectively, these data indicate that "clutch effects" caused by genetic and/or maternal influences can strongly affect patterns of heart function during development within cave coqui populations. This phenomenon also occurs in bird eggs and armadillo neonates, suggesting that physiological variation attributable to clutch effects might be a widespread phenomenon in vertebrates.

  17. Heart rate variability and salivary cortisol in very preterm children during school age.

    Science.gov (United States)

    Urfer-Maurer, Natalie; Ludyga, Sebastian; Stalder, Tobias; Brand, Serge; Holsboer-Trachsler, Edith; Gerber, Markus; Grob, Alexander; Weber, Peter; Lemola, Sakari

    2018-01-01

    The autonomic nervous system (ANS) plays a major role in the human stress response and reflects physical and psychological adaptability to a changing environment. Long-term exposure to early life stressors may alter the function of the ANS. The present study examines differences in the ANS between children born very preterm and full-term as well as the association between the ANS and the hypothalamic-pituitary-adrenal (HPA) axis, the other main branch of the human stress system. Fifty-four healthy children born very preterm (position at rest (wake) and during different sleep stages (stage 2 sleep, slow wave sleep, rapid-eye-movement sleep). Autonomic function was assessed by use of heart rate variability, specifically low frequency power (LF), high frequency power (HF), total spectral power (Tot Pow), and the LF/HF ratio. HPA axis activity was measured using salivary cortisol the next morning at awakening, 10, 20, and 30min later. Children born very preterm had lower LF/HF ratio during wake and stage 2 sleep compared to full-term children. Moreover, higher LF, Tot Pow, and LF/HF ratio during wake, stage 2 sleep, and REM sleep were related to more post-awakening cortisol secretion. The present study provides evidence on long-term ANS alterations after very preterm birth. Moreover, findings suggest a relation between the ANS and the HPA axis and therefore support the notion of mutual feedback between the two human stress systems. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Gender- and age-related differences in heart rate dynamics: are women more complex than men?

    Science.gov (United States)

    Ryan, S. M.; Goldberger, A. L.; Pincus, S. M.; Mietus, J.; Lipsitz, L. A.

    1994-01-01

    OBJECTIVES. This study aimed to quantify the complex dynamics of beat-to-beat sinus rhythm heart rate fluctuations and to determine their differences as a function of gender and age. BACKGROUND. Recently, measures of heart rate variability and the nonlinear "complexity" of heart rate dynamics have been used as indicators of cardiovascular health. Because women have lower cardiovascular risk and greater longevity than men, we postulated that there are important gender-related differences in beat-to-beat heart rate dynamics. METHODS. We analyzed heart rate dynamics during 8-min segments of continuous electrocardiographic recording in healthy young (20 to 39 years old), middle-aged (40 to 64 years old) and elderly (65 to 90 years old) men (n = 40) and women (n = 27) while they performed spontaneous and metronomic (15 breaths/min) breathing. Relatively high (0.15 to 0.40 Hz) and low (0.01 to 0.15 Hz) frequency components of heart rate variability were computed using spectral analysis. The overall "complexity" of each heart rate time series was quantified by its approximate entropy, a measure of regularity derived from nonlinear dynamics ("chaos" theory). RESULTS. Mean heart rate did not differ between the age groups or genders. High frequency heart rate power and the high/low frequency power ratio decreased with age in both men and women (p gender-as well as age-related differences in heart rate dynamics. Whether these gender differences are related to lower cardiovascular disease risk and greater longevity in women requires further study.

  19. Association of impaired heart rate recovery with cardiopulmonary complications after lung cancer resection surgery.

    Science.gov (United States)

    Ha, Duc; Choi, Humberto; Zell, Katrina; Raymond, Daniel P; Stephans, Kevin; Wang, Xiao-Feng; Videtic, Gregory; McCarthy, Kevin; Minai, Omar A; Mazzone, Peter J

    2015-04-01

    Patients who undergo lung resection surgery are at risk for postoperative morbidity and mortality. Appropriate selection of the surgical candidate is crucial in the treatment of lung cancer. Heart rate recovery is a measure of physical fitness. We aimed to investigate the association of impaired heart rate recovery with cardiopulmonary complications after lung resection surgery for treatment of lung cancer. Data from consecutive patients who, between 2009 and 2013, underwent heart rate recovery evaluation after 6-minute walk tests before lung resection surgery were retrospectively reviewed. Impaired heart rate recovery was defined as a 12-beat or less decrease in peak heart rate at 1 minute after the 6-minute walk test. Postoperative cardiopulmonary complications were as defined by the Society of Thoracic Surgeons General Thoracic Surgery Database. Logistic regression was performed, including previously known risk factors for postoperative complications after lung resection surgery. A total of 96 patients had heart rate recovery evaluated within 6 months of lung resection surgery for treatment of lung cancer. Thirty-one patients had impaired heart rate recovery, 17 of whom (55%) had cardiopulmonary complications. A total of 65 patients had normal heart rate recovery, 17 of whom (26%) had cardiopulmonary complications. In multivariable logistic regression analysis, impaired heart rate recovery was significantly associated with postoperative cardiopulmonary complications (odds ratio, 4.97; confidence interval, 1.79-13.8; P = .002). No patient died within 30 days after surgery. Impaired heart rate recovery after the 6-minute walk test is associated with postoperative cardiopulmonary complications in patients who underwent lung resection surgery for treatment of lung cancer. Copyright © 2015 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

  20. Impact of Narrative Expressive Writing on Heart Rate, Heart Rate Variability, and Blood Pressure After Marital Separation.

    Science.gov (United States)

    Bourassa, Kyle J; Allen, John J B; Mehl, Matthias R; Sbarra, David A

    Divorce is a common stressor that is associated with increased risk for poor long-term physical and mental health. Using an experimental design, the current study examined the impact of expressive writing (EW) on average heart rate (HR), HR variability (HRV), and blood pressure (BP) 7.5 months later. Participants from a community sample of recently separated adults (N = 109) were assigned to one of three conditions: traditional EW, narrative EW, or a control writing condition, and were assessed three times for an average of 7.5 months. Each study visit included 27 minutes of physiological assessment; the primary outcomes at each assessment were mean-level HR, HRV, BP scores averaged across six different tasks. Participants in the traditional EW condition did not significantly differ from control participants in their later HR, HRV, or BP. However, relative to control participants, those in the narrative EW condition had significantly lower HR (B = -3.41, 95% confidence interval = -5.76 to -1.06, p = .004) and higher HRV 7.5 months later (B = 0.41, 95% confidence interval = 0.16 to 0.74, p = .001). When comparing narrative EW participants to those in the traditional EW and control writing as a single group, these effects remained and were moderately sized, Cohen d values of -0.61 and 0.60, respectively, and durable across all task conditions when analyzed in independent models. The writing condition groups did not differ in their later BP. Narrative EW decreased HR and increased HRV after marital separation but did not affect BP. We discuss the possible disconnect between psychology and physiology in response to EW, as well as possible future clinical applications after marital separation.

  1. Heart rate response to exercise in heart failure patients: The prognostic role of metabolic-chronotropic relation and heart rate recovery.

    Science.gov (United States)

    Hajdusek, Pavel; Kotrc, Martin; Kautzner, Josef; Melenovsky, Vojtech; Benesova, Eva; Jarolim, Petr; Benes, Jan

    2017-02-01

    The dynamics of the sinus node response to exercise is linked to functional capacity and outcome in heart failure (HF). The goal of the work was to analyze determinants and impacts of cardio-acceleration, described by the concept of metabolic-chronotropic relation (MCR) and of cardio-deceleration, described by heart rate recovery (HRR). A cohort of 25 healthy controls and 78 patients with advanced systolic HF and optimized medical and/or device therapy (97% receiving beta-blockers, 54% ICD) underwent maximal cardiopulmonary exercise test and were prospectively followed. HF patients had impaired exercise performance compared with controls (pVO2 15±4 vs. 29±7ml.kg-1.min-1, pslope (0.54±0.24 vs. 0.90±0.15, pslope was inversely associated with beta-blocker dose (r=-0.24), NYHA class (r=-0.28) and HF duration (r=-0.25), whereas HRR with estimated glomerular filtration rate (eGFR, r=0.39), age (r=-0.28) and BMI (r=-0.31, all pslope (p=0.02) but not HRR (p=0.19). MCR slope (but not HRR) was a significant outcome predictor (p=0.02 for Cox unadjusted model) even after adjustment for LVEF, serum natrium, systolic blood pressure, eGFR and NT-proBNP (p=0.04). MCR slope is associated with different clinical variables than HRR. Compared to HRR, MCR slope provides significant prognostic information in HF patients. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  2. Influence of deep breathing exercise on spontaneous respiratory rate and heart rate variability: a randomised controlled trial in healthy subjects.

    Science.gov (United States)

    Tharion, Elizabeth; Samuel, Prasanna; Rajalakshmi, R; Gnanasenthil, G; Subramanian, Rajam Krishna

    2012-01-01

    Studies show that yogic type of breathing exercises reduces the spontaneous respiratory rate. However, there are no conclusive studies on the effects of breathing exercise on heart rate variability. We investigated the effects of non-yogic breathing exercise on respiratory rate and heart rate variability. Healthy subjects (21-33 years, both genders) were randomized into the intervention group (n=18), which performed daily deep breathing exercise at 6 breaths/min (0.1 Hz) for one month, and a control group (n=18) which did not perform any breathing exercise. Baseline respiratory rate and short-term heart rate variability indices were assessed in both groups. Reassessment was done after one month and the change in the parameters from baseline was computed for each group. Comparison of the absolute changes [median (inter-quartile ranges)] of the parameters between the intervention and control group showed a significant difference in the spontaneous respiratory rate [intervention group -2.50 (-4.00, -1.00), control group 0.00 (-1.00, 1.00), cycles/min, Prate and cardiac autonomic modulation of the intervention group were significant, when compared to the changes in the control group. Thus practice of deep slow breathing exercise improves heart rate variability in healthy subjects, without altering their cardiac autonomic balance. These findings have implications in the use of deep breathing exercises to improve cardiac autonomic control in subjects known to have reduced heart rate variability.

  3. The effect of real-time vibrotactile feedback delivered through an augmented fork on eating rate, satiation, and food intake.

    Science.gov (United States)

    Hermans, Roel C J; Hermsen, Sander; Robinson, Eric; Higgs, Suzanne; Mars, Monica; Frost, Jeana H

    2017-06-01

    Eating rate is a basic determinant of appetite regulation, as people who eat more slowly feel sated earlier and eat less. Without assistance, eating rate is difficult to modify due to its automatic nature. In the current study, participants used an augmented fork that aimed to decelerate their rate of eating. A total of 114 participants were randomly assigned to the Feedback Condition (FC), in which they received vibrotactile feedback from their fork when eating too fast (i.e., taking more than one bite per 10 s), or a Non-Feedback Condition (NFC). Participants in the FC took fewer bites per minute than did those in the NFC. Participants in the FC also had a higher success ratio, indicating that they had significantly more bites outside the designated time interval of 10 s than did participants in the NFC. A slower eating rate, however, did not lead to a significant reduction in the amount of food consumed or level of satiation. These findings indicate that real-time vibrotactile feedback delivered through an augmented fork is capable of reducing eating rate, but there is no evidence from this study that this reduction in eating rate is translated into an increase in satiation or reduction in food consumption. Overall, this study shows that real-time vibrotactile feedback may be a viable tool in interventions that aim to reduce eating rate. The long-term effectiveness of this form of feedback on satiation and food consumption, however, awaits further investigation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Intrathecal fentanyl blockade of afferent neural feedback from skeletal muscle during exercise in heart failure patients: Influence on circulatory power and pulmonary vascular capacitance.

    Science.gov (United States)

    Van Iterson, Erik H; Snyder, Eric M; Joyner, Michael J; Johnson, Bruce D; Olson, Thomas P

    2015-12-15

    Secondary pulmonary hypertension is common in heart failure (HF) patients. We hypothesized that inhibition of feedback from locomotor muscle group III/IV neurons contributes to reduced pulmonary vascular pressures independent of changes in cardiac function during exercise in HF. 9 HF patients (ages, 60 ± 2; EF, 26.7 ± 1.9%; New York Heart Association classes, I-III) and 9 age/gender matched controls (ages, 63 ± 2) completed five-minutes of constant-load cycling (65% Workloadpeak) with intrathecal fentanyl or placebo on randomized separate days. Mean arterial pressure (MAP), heart rate (HR), end-tidal partial pressure of CO2 (PETCO2), and oxygen consumption (VO2) were measured at rest and exercise. Non-invasive surrogates for cardiac power (circulatory power, CircP=VO2 × MAP), stroke volume (oxygen pulse, O2pulse=VO2/HR), and pulmonary arterial pressure (GXCAP=O2pulse × PETCO2) were calculated. At rest and end-exercise, differences between fentanyl versus placebo were not significant for CircP in HF or controls. Differences between fentanyl versus placebo for GXCAP were not significant at rest in HF or controls. At end-exercise, GXCAP was significantly higher with fentanyl versus placebo in HF (691 ± 59 versus 549 ± 38 mL/beat × mmHg), but not controls (536 ± 59 versus 474 ± 43 mL/beat × mmHg). Slopes (rest to end-exercise) for GXCAP were significantly higher with fentanyl versus placebo in HF (95.1 ± 9.8 versus 71.6 ± 6.0 mL/beat × mmHg), but not controls (74.3 ± 9.5 versus 60.8 ± 6.5 mL/beat × mmHg). CircP slopes did not differ between fentanyl versus placebo in HF or controls (p>0.05). We conclude that feedback from locomotor muscle group III/IV neurons may evoke increases in pulmonary vascular pressures independent of changes in cardiac function during exercise in HF. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  5. ROC Analysis and a Realistic Model of Heart Rate Variability

    CERN Document Server

    Thurner, S; Teich, M C; Thurner, Stefan; Feurstein, Markus C.; Teich, Malvin C.

    1998-01-01

    We have carried out a pilot study on a standard collection of electrocardiograms from patients who suffer from congestive heart failure, and subjects without cardiac pathology, using receiver-operating-characteristic (ROC) analysis. The scale-dependent wavelet-coefficient standard deviation superior to two commonly used measures of cardiac dysfunction when the two classes of patients cannot be completely separated. A jittered integrate-and-fire model with a fractal Gaussian-noise kernel provides a realistic simulation of heartbeat sequences for both heart-failure patients and normal subjects.

  6. Pathogen-induced heart rate changes associated with cholinergic nervous system activation.

    Science.gov (United States)

    Fairchild, Karen D; Srinivasan, Varadamurthy; Moorman, J Randall; Gaykema, Ronald P A; Goehler, Lisa E

    2011-02-01

    The autonomic nervous system plays a central role in regulation of host defense and in physiological responses to sepsis, including changes in heart rate and heart rate variability. The cholinergic anti-inflammatory response, whereby infection triggers vagal efferent signals that dampen production of proinflammatory cytokines, would be predicted to result in increased vagal signaling to the heart and increased heart rate variability. In fact, decreased heart rate variability is widely described in humans with sepsis. Our studies elucidate this apparent paradox by showing that mice injected with pathogens demonstrate transient bradyarrhythmias of vagal origin in a background of decreased heart rate variability (HRV). Intraperitoneal injection of a large inoculum of Gram-positive or Gram-negative bacteria or Candida albicans rapidly induced bradyarrhythmias of sinus and AV nodal block, characteristic of cardiac vagal firing and dramatically increased short-term HRV. These pathogen-induced bradycardias were immediately terminated by atropine, an antagonist of muscarinic cholinergic receptors, demonstrating the role of vagal efferent signaling in this response. Vagal afferent signaling following pathogen injection was demonstrated by intense nuclear c-Fos activity in neurons of the vagal sensory ganglia and brain stem. Surprisingly, pathogen-induced bradycardia demonstrated rapid and prolonged desensitization and did not recur on repeat injection of the same organism 3 h or 3 days after the initial exposure. After recovery from the initial bradycardia, depressed heart rate variability developed in some mice and was correlated with elevated plasma cytokine levels and mortality. Our findings of decreased HRV and transient heart rate decelerations in infected mice are similar to heart rate changes described by our group in preterm neonates with sepsis. Pathogen sensing and signaling via the vagus nerve, and the desensitization of this response, may account for periods of

  7. Effect of Exercise Testing on Short-term Heart Rate Variability in Patients with Coronary Heart Disease

    DEFF Research Database (Denmark)

    Niu, Hui-Yan; Zhang, Dai-Fu; Liang, Bo

    2005-01-01

    Objective To study the effect of exercise testing on short term heart rate variability in patients with CHD.Methods In 12 patients with CHD and 12 age-and sex-matched healthy controls, short-term frequency domain analysis was performed at respective stage before, during and after ET.Results It sh......Objective To study the effect of exercise testing on short term heart rate variability in patients with CHD.Methods In 12 patients with CHD and 12 age-and sex-matched healthy controls, short-term frequency domain analysis was performed at respective stage before, during and after ET...

  8. A healthy heart is not a metronome: An integrative review of the heart’s anatomy and heart rate variability

    Directory of Open Access Journals (Sweden)

    Fredric Bruce Shaffer

    2014-09-01

    Full Text Available Heart rate variability (HRV, the change in the time intervals between adjacent heartbeats, is an emergent property of interdependent regulatory systems that operate on different time scales to adapt to challenges and achieve optimal performance. This article briefly reviews neural regulation of the heart, and its basic anatomy, the cardiac cycle, and the sinoatrial and atrioventricular pacemakers. The cardiovascular regulation center in the medulla integrates sensory information and input from higher brain centers, and afferent cardiovascular system inputs to adjust heart rate and blood pressure via sympathetic and parasympathetic efferent pathways. This article reviews sympathetic and parasympathetic influences on the heart, and examines the interpretation of HRV and the association between reduced HRV, risk of disease and mortality, and the loss of regulatory capacity. This article also discusses the intrinsic cardiac nervous system and the heart-brain connection, through which afferent information can influence activity in the subcortical and frontocortical areas, and motor cortex. It also considers new perspectives on the putative underlying physiological mechanisms and properties of the ultra-low-frequency (ULF, very-low-frequency (VLF, low-frequency (LF, and high-frequency (HF bands. Additionally, it reviews the most common time and frequency domain measurements as well as standardized data collection protocols. In its final section, this article integrates Porges’ polyvagal theory, Thayer and colleagues’ neurovisceral integration model, Lehrer, Vaschillo, and Vaschillo’s resonance frequency model, and the Institute of HeartMath’s coherence model. The authors conclude that a coherent heart is not a metronome because its rhythms are characterized by both complexity and stability over longer time scales. Future research should expand understanding of how the heart and its intrinsic nervous system influence the brain.

  9. Effects of Interval Training Programme on Resting Heart Rate in ...

    African Journals Online (AJOL)

    Conclusion: It was concluded that moderate intensity interval training programs is effective in the non-pharmacological adjunct management of hypertension and may prevent cardiovascular event through the down regulation of HR in hypertension. Keywords: Hypertension; Interval exercise; cardiovascular risk factor; Heart ...

  10. veteran athletes exercise at higher maximum heart rates than

    African Journals Online (AJOL)

    Maximal HR in veteran athletes during specific sporting activities was significantly higher than that attained ... false-positive results due to the athletic heart syndrome have been described,13 it is accepted that a positive test is a risk .... group (210 (21) v. 185. (18) mmHg, P < 0.05, Table ill). Exercise time to fatigue in the. lID I ...

  11. Effects of Interval Training Programme on Resting Heart Rate in ...

    African Journals Online (AJOL)

    DATONYE ALASIA

    Student's t and Pearson correlation tests were used in data analysis. Results: Findings of the study revealed significant effect of exercise training program on HR ... presentwith a series of functional and anatomic deficits, such as increasedvascular resistance, vessel rarefaction, increased heart energy expenditure, increased.

  12. Cardiac concomitants of feedback processing.

    NARCIS (Netherlands)

    Crone, E.A.; van der Veen, F.M.; van der Molen, M.W.; Somsen, R.J.; van Beek, B.; Jennings, J.R.

    2003-01-01

    This study examined the heart rate changes associated with positive and negative performance feedback in a probabilistic learning task derived from Holroyd and Coles (2002). In this task, 21 20-29 yr old college students were presented with six stimuli and asked to respond by pressing a left versus

  13. A new lattice hydrodynamic model based on control method considering the flux change rate and delay feedback signal

    Science.gov (United States)

    Qin, Shunda; Ge, Hongxia; Cheng, Rongjun

    2018-02-01

    In this paper, a new lattice hydrodynamic model is proposed by taking delay feedback and flux change rate effect into account in a single lane. The linear stability condition of the new model is derived by control theory. By using the nonlinear analysis method, the mKDV equation near the critical point is deduced to describe the traffic congestion. Numerical simulations are carried out to demonstrate the advantage of the new model in suppressing traffic jam with the consideration of flux change rate effect in delay feedback model.

  14. Patient Feedback as a Quality Improvement Strategy in an Acute Care, Inpatient Unit: An Investigation of Outcome and Readmission Rates.

    Science.gov (United States)

    Reese, Robert J; Duncan, Barry L; Kodet, Jonathan; Brown, Holly M; Meiller, Carolyn; Farook, Minnah W; Lengerich, Alex J; Vasilj, Igor; Hong, Sang-Hee; Bohanske, Robert T

    2017-07-13

    High psychiatric readmission rates continue while evidence suggests that care is not perceived by patients as "patient centered." Research has focused on aftercare strategies with little attention to the inpatient treatment itself as an intervention to reduce readmission rates. Quality improvement strategies based on patient-centered care may offer an alternative. We evaluated outcomes and readmission rates using a benchmarking methodology with a naturalistic data set from an inpatient psychiatric facility (N = 2,247) that used a quality-improvement strategy called systematic patient feedback. Benchmarks were constructed using randomized clinical trials (RCTs) from inpatient treatment for depression, RCTs from patient feedback in outpatient settings, and national data on psychiatric hospital readmission rates. A systematic patient feedback system, the Partners for Change Outcome Management System (PCOMS), was used. Overall pre-post effect sizes were d = 1.33 and d = 1.38 for patients diagnosed with a mood disorder. These effect sizes were statistically equivalent to RCT benchmarks for feedback and depression. Readmission rates were 6.1% (30 days), 9.5% (60 days), and 16.4% (180 days), all lower than national benchmarks. We also found that patients who achieved clinically significant treatment outcomes were less likely to be readmitted. We tentatively suggest that a focus on real-time patient outcomes as well as care that is "patient centered" may provide a path toward lower readmission rates in addition to other evidence-based strategies after discharge. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  15. Effects of melatonin and ethanol on the heart rate of Daphnia magna

    Directory of Open Access Journals (Sweden)

    Rebecca Kohn

    2009-01-01

    Full Text Available Melatonin, an endogenous hormone that may regulate circadian rhythms by modulating cholinergic activity, is increasing in popular use as a natural treatment for sleep disorders. However, the effects of melatonin on the human heart are not well characterized, and the consequences of combining alcohol with melatonin are unknown. The myogenic heart of the water flea Daphnia magna (D. magna is regulated by inhibitory cholinergic neurons that modulate cardiac function, including heart rate. D. magna is a useful model organism for cardiovascular function, due to its physical transparency and susceptibility to cardioactive drugs known to affect the human heart. In this study, the effects of immersion in 10 mg/L melatonin and 5% ethanol on the heart rate of D. magna were quantified. Two-hour exposure to melatonin caused a significant decrease in heart rate, from 228 ± 2 bpm to 167 ± 8 bpm. Six-minute immersion in ethanol also significantly depressed the heart rate to 176 ± 10 bpm. Pretreatment with melatonin prior to the addition of ethanol resulted in a greater decrease in heart rate (89 ± 7 bpm than ethanol or melatonin alone. These findings indicate that melatonin and alcohol may combine to cause a greater depressive effect on cardiac function.

  16. Design of heart rate monitor based on piezoelectric sensor using an Arduino

    Science.gov (United States)

    Setyowati, Veni; Muninggar, Jodelin; Shanti. N. A, Made R. S.

    2017-01-01

    Reading of result heart rate using an acoustic stethoscope needs a particular skill, quiet environment, and hearing sensitivity. This project had the purpose design of a user-friendly automatic heart rate monitor and especially in a noisy area which to eliminate problems and incorrect reading of result. The liquid crystal display shows a heart rate as a result of measurements. The design of the heart rate monitor has two main parts; the signal recorder that a piezoelectric sensor, a filter, and an amplifier as recorder. The second parts was Arduino microcontroller with reinforced. Besides, three supporting buttons provided as the manual switches, the ‘on’, the ‘start’, and ‘reset’ buttons. The values acquired from the heart rate monitor indicate that those were on the Vernier BPS-BTA value range. The measurement error factor of the heart rate monitor then compared to the Vernier BPS-BTA test device was 3.15%. Besides, the value of statistical independent-test indicates that there is no significant difference (P = 0.971) between the heart rate monitor device and the Vernier BPS-BTA. In conclusion, this device was ready to be used because it has almost the same accuracy with the standart device.

  17. Minimal changes in heart rate of incubating American Oystercatchers (Haematopus palliatus) in response to human activity

    Science.gov (United States)

    Borneman, Tracy E.; Rose, Eli T.; Simons, Theodore R.

    2014-01-01

    An organism's heart rate is commonly used as an indicator of physiological stress due to environmental stimuli. We used heart rate to monitor the physiological response of American Oystercatchers (Haematopus palliatus) to human activity in their nesting environment. We placed artificial eggs with embedded microphones in 42 oystercatcher nests to record the heart rate of incubating oystercatchers continuously for up to 27 days. We used continuous video and audio recordings collected simultaneously at the nests to relate physiological response of birds (heart rate) to various types of human activity. We observed military and civilian aircraft, off-road vehicles, and pedestrians around nests. With the exception of high-speed, low-altitude military overflights, we found little evidence that oystercatcher heart rates were influenced by most types of human activity. The low-altitude flights were the only human activity to significantly increase average heart rates of incubating oystercatchers (12% above baseline). Although statistically significant, we do not consider the increase in heart rate during high-speed, low-altitude military overflights to be of biological significance. This noninvasive technique may be appropriate for other studies of stress in nesting birds.

  18. [Interrelation between well-being of the mother and heart rate variability of her preterm infant].

    Science.gov (United States)

    Djordjevic, Dragana; Linderkamp, Otwin; Brüssau, Jürgen; Cierpka, Manfred

    2007-01-01

    The relationship between mothers' well-being and the heart rate variability of their preterm babies was investigated. In order to study a possible influence of the mother's well-being on the calming quality of her voice and thereby on the heart rate variability of her preterm infant, maternal/paternal stress and competences as well as family functionality were assessed via respective questionnaires. (N = 30) Preterm babies at the postnatal age of approximately 4 weeks were acoustically stimulated with the voice of their own mother. Various heart rate variability measures (NN interval mean value, NN interval median, variance of NN intervals, standard deviation of NN intervals, pnn 6,25, RMSSD, SDSD and RSA) were recorded 15 minutes before, 15 minutes during and 15 minutes after the acoustic stimulation. Non-REM sleep sections of 2 minutes duration were matter of analyses. The correlations between the mothers' well-being and their babies' heart rate variability indicate a strong relationship. The correlations point out that a higher family functionality is associated with a higher heart rate variability of preterm babies. Contradictory to the expectations, higher burden and lower resources as well as lower competences of the mothers were associated with a higher heart rate variability of the preterm babies. Simultaneous real-time investigations of the mothers' and the babies' heart rate variability during a live mother-baby-interaction seems necessary to provide further explanations.

  19. Heart rate as a sublethal indicator of thermal stress in juvenile freshwater mussels.

    Science.gov (United States)

    Pandolfo, Tamara J; Cope, W Gregory; Arellano, Consuelo

    2009-11-01

    Freshwater mussels (Unionoida) are one of the most sensitive and rapidly declining faunal groups in the world. Rising water temperatures, caused by industrial discharges, land development, or climate change can further challenge threatened unionid communities. The direct relationship between heart rate and temperature in ectotherms enables the use of heart rate as an indicator of whole-animal thermal stress. The purpose of this study was to assess the utility of heart rate as an indicator of thermal stress in freshwater mussels. Seven species of juvenile mussels (Lampsilis siliquoidea, Potamilus alatus, Ligumia recta, Ellipsaria lineolata, Megalonaias nervosa, Alasmidonta varicosa, and Villosa delumbis) were evaluated in response to a range of experimental temperatures (20-36 degrees C) at three acclimation temperatures (17, 22, and 27 degrees C). Heart rate was measured by direct visual observation through transparent mussel shells. The average heart rate for all 7 species at 20 degrees C was 55bpm, with a range from 38bpm (L. recta) to 65bpm (P. alatus). L. recta and V. delumbis exhibited significant changes in heart rate with increasing temperature at each of the three acclimation temperatures. The use of heart rate appears to be a suitable indicator of thermal stress in some unionid mussels.

  20. Triboelectric Nanogenerator Enabled Body Sensor Network for Self-Powered Human Heart-Rate Monitoring.

    Science.gov (United States)

    Lin, Zhiming; Chen, Jun; Li, Xiaoshi; Zhou, Zhihao; Meng, Keyu; Wei, Wei; Yang, Jin; Wang, Zhong Lin

    2017-09-26

    Heart-rate monitoring plays a critical role in personal healthcare management. A low-cost, noninvasive, and user-friendly heart-rate monitoring system is highly desirable. Here, a self-powered wireless body sensor network (BSN) system is developed for heart-rate monitoring via integration of a downy-structure-based triboelectric nanogenerator (D-TENG), a power management circuit, a heart-rate sensor, a signal processing unit, and Bluetooth module for wireless data transmission. By converting the inertia energy of human walking into electric power, a maximum power of 2.28 mW with total conversion efficiency of 57.9% was delivered at low operation frequency, which is capable of immediately and sustainably driving the highly integrated BSN system. The acquired heart-rate signal by the sensor would be processed in the signal process circuit, sent to an external device via the Bluetooth module, and displayed on a personal cell phone in a real-time manner. Moreover, by combining a TENG-based generator and a TENG-based sensor, an all-TENG-based wireless BSN system was developed, realizing continuous and self-powered heart-rate monitoring. This work presents a potential method for personal heart-rate monitoring, featured as being self-powered, cost-effective, noninvasive, and user-friendly.

  1. [Heart rate measurement for determination of training intensity in outpatient pulmonary sport groups].

    Science.gov (United States)

    Baumann, H J; Kluge, S; Klose, H; Hellweger, A; Braumann, K M; Meyer, A

    2009-02-01

    Exercise training is an integral component of the management of patients with asthma and COPD. A training intensity of 60-80% of maximum oxygen uptake (VO(2)max) has been recommended. Instead of ergospirometry measurement of heart rate can be used for training guidance. It is unknown whether the given target can be reached in outpatient training groups with substantial heterogeneity concerning diagnosis, disease severity, and age. 61 adult patients (m = 15, w = 46; 63 +/- 9 years) with asthma (n = 50) or COPD (n = 11) exercised in groups of ambulant lung sports. An individualized target heart rate was calculated corresponding to an intensity of 60% to 80% of calculated VO(2)max which was equivalent to a heart rate from 97 to 137 beats per minute in the population studied. Heart rate, as a measure of the intensity of charge, was measured continuously with pulse frequency meters. All but one asthma patient exercised in the targeted heart rate range. Patients reached 81 +/- 9% of the training goal of calculated 80% VO(2)max (asthma patients: 79 +/- 9% vs. COPD patients: 88 +/- 9%, p heart rate target range. COPD patients were training at a significantly higher relative training intensity. Heart rate is an easy to use parameter for training guidance.

  2. The relationship between heart rate as an indicator of work hardness and results of dynamometry.

    Science.gov (United States)

    Sadeghi, Nasrin; Tolide-ie, Hamidreza; Ghaderi, Fatemeh

    2012-01-01

    Heart rate is associated with work hardness and increase linearly with its increasing. In the average of energy consumption, heart rate measurement is simple but non-accurate method for calculation of work hardness. Our purpose in this research was to evaluate the relationship between heart rate and dynamometry results with hypothesis of work hardness effectiveness on the human power. This study was conducted on 102 porcelain workers. Participants were selected randomly. The research tools include stethoscope, the dynamometer. Heart rate, and pinch, grip, and back-leg-chest force were measured and relationships between variables were analyzed with Pearson correlation test and independent T-test using Spss 16 software. The average heart rate of participants were 4.11 ± 1.79 with minimum 60 and maximum 120. The average force of pinch, grip, and back-leg-chest were 8.9 ± 3.20, 4.2 ± 4.5 and 9.36 ± 6.55, respectively. Work hardness for 3.86% of workers were light, 7.12% were moderate and 1% were heavy. Pinch, grip, and back-leg-chest force relation with heart rate were not significant (r=0.01, p=0.85), (r=-0.03, p=0.74), and (r=0.05, p= 0.59), respectively. There was no correlation between heart rate and work hardness. So we can't use the dynamometry results to determine of work hardness.

  3. Heart rate variability and Omega-3 Index in euthymic patients with bipolar disorders.

    Science.gov (United States)

    Voggt, A; Berger, M; Obermeier, M; Löw, A; Seemueller, F; Riedel, M; Moeller, H J; Zimmermann, R; Kirchberg, F; Von Schacky, C; Severus, E

    2015-02-01

    Affective disorders are associated with an increased risk of cardiovascular disease, which, at least partly, appears to be independent of psychopharmacological treatments used to manage these disorders. Reduced heart rate variability (SDNN) and a low Omega-3 Index have been shown to be associated with increased risk for death after myocardial infarction. Therefore, we set out to investigate heart rate variability and the Omega-3 Index in euthymic patients with bipolar disorders. We assessed heart rate variability (SDNN) and the Omega-3 Index in 90 euthymic, mostly medicated patients with bipolar disorders (Bipolar-I, Bipolar-II) on stable psychotropic medication, free of significant medical comorbidity and in 62 healthy controls. Heart rate variability was measured from electrocardiography under a standardized 30 minutes resting state condition. Age, sex, BMI, smoking, alcohol consumption and caffeine consumption as potential confounders were also assessed. Heart rate variability (SDNN) was significantly lower in patients with bipolar disorders compared to healthy controls (35.4 msec versus 60.7 msec; Pbipolar disorders versus healthy controls) and age significantly predicted heart rate variability (SDNN). Heart rate variability (SDNN) may provide a useful tool to study the impact of interventions aimed at reducing the increased risk of cardiovascular disease in euthymic patients with bipolar disorders. The difference in SDNN between cases and controls cannot be explained by a difference in the Omega-3 Index. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  4. Daily physical activity and heart rate response in people with a unilateral traumatic transtibial amputation.

    Science.gov (United States)

    Bussmann, Johannes B; Schrauwen, Hannelore J; Stam, Henk J

    2008-03-01

    To test the hypothesis that people with a unilateral traumatic transtibial amputation are less active than people without an amputation, and to explore whether both groups have a similar heart rate response while walking. A case-comparison study. General community. Nine subjects with a unilateral traumatic transtibial amputation and 9 matched subjects without known impairments. Not applicable. Percentage of dynamic activities in 48 hours (expressing activity level). Additionally, we examined heart rate and percentage heart rate reserve during walking (expressing heart rate response) and body motility during walking (expressing walking speed). These parameters were objectively measured at participants' homes on 2 consecutive days. Subjects with an amputation showed a lower percentage of dynamic activities (6.0% vs 11.7% in a 48-h period, P=.02). No significant differences were found between the 2 groups in heart rate (91.1 bpm vs 89.5 bpm, P=.86) and percentage heart rate reserve during walking (28.2% vs 27.5%, P=1.0). Body motility during walking was lower in the amputation group (.14 g vs .18 g, Ptranstibial amputation are considerably less active than persons without known impairments. The results indicate that heart rate response during walking is similar in both groups, and is probably regulated by adapting one's walking speed.

  5. Change of Diurnal Heart Rate Patterns During Pregnancy and Lactation in Dogs (Canis familiaris

    Directory of Open Access Journals (Sweden)

    Häggström J

    2003-09-01

    Full Text Available Pregnancy and lactation involve great demands on the cardiovascular system. The purpose of this study was to investigate how the heart rate and diurnal heart rate pattern change when dogs become pregnant or lactate. Five clinically healthy female beagle dogs were mated, and delivered three to seven healthy puppies. The heart rate was investigated with 24-h ECG (Holter once during anoestrus, at 3, 5, 7 and 9 weeks of pregnancy, and at week 4 postpartum (lactation. However, at 9 weeks, the ECG could not be recorded for the fully 24 h in 4 of 5 dogs, because labour started and the dogs then appeared disturbed by the recordings. The results at this date are not included in the statistical comparison. The heart rate increased progressively during pregnancy and was still elevated at 4 weeks of lactation. During late pregnancy the difference in heart rates between daytime and nighttime became smaller, but the heart rate was significantly higher in daytime in all periods. In conclusion, the increased heart rates during pregnancy and lactation reflect increased demands on the cardiovascular system and may be important to consider in clinical practice.

  6. The effect of respiratory oscillations in heart rate on detrended fluctuation analysis

    Science.gov (United States)

    Govindan, Rathinaswamy B.; Kota, Srinivas; Al-Shargabi, Tareq; Swisher, Christopher B.; du Plessis, Adre

    2017-10-01

    Characterization of heart rate using detrended fluctuation analysis (DFA) is impeded by respiratory oscillations. In particular, the short-term exponent measured from 15 to 30 beats is compromised in the DFA. We reconstruct respiratory signal from electrocardiograms and attenuate the respiratory oscillation in the heart rate using a frequency-dependent subtraction approach. We validate this method by applying it to an electrocardiogram signal simulated using a coupled differential equation with the respiratory oscillation modelled using a sine function. The exponent estimated using the proposed approach agreed with the exponent incorporated in the model within a narrow range. In contrast, the exponent obtained from the raw data deviated from the expected value. Furthermore, the exponents obtained for the raw heart rate are smaller than the exponents obtained for the respiration oscillation attenuated heart rate. We apply this approach to heart rate measured from 12 preterm infants that were being treated for prematurity related complications. As observed in the simulated data, we show that compared to the raw heart rate, the respiratory oscillation attenuated heart rate shows higher short-term exponent (p < 0.001).

  7. Prognostic Significance of Heart Rate and its Long-term Trend in Cardiac Transplant Patients.

    Science.gov (United States)

    Barge-Caballero, Eduardo; Jiménez-López, Jesús; Chávez-Leal, Sergio; Barge-Caballero, Gonzalo; Paniagua-Martin, María Jesús; Marzoa Rivas, Raquel; Grille-Cancela, Zulaika; Cuenca-Castillo, José Joaquín; Castro-Beiras, Alfonso; Crespo-Leiro, María G

    2015-11-01

    The aim of the present study was to examine the prognostic significance of heart rate and its trend in heart transplantation. This observational study enrolled 170 patients who received a bicaval heart transplant between 1995 and 2005; all were in sinus rhythm. The resting heart rate was determined via electrocardiography at the end of the first posttransplant year and annually until the tenth year. Cox analysis was used to evaluate the incidence of adverse events with a mean (standard deviation) follow-up of 8.9 (3.1) years. The primary study end point was the composite outcome of death or graft dysfunction. The resting heart rate at the end of the first posttransplant year was an independent predictor of the primary composite end point (hazard ratio=1.054; 95% confidence interval, 1.028-1.080; P<.001) and was significantly associated with total mortality (hazard ratio=1.058; 95% confidence interval, 1.030-1.087; P<.001) and mortality from cardiac causes (hazard ratio=1.069; 95% confidence interval, 1.026-1.113; P=.001), but not with graft dysfunction (hazard ratio=1.028; 95% confidence interval, 0.989-1.069; P=.161). For patients with a heart rate ≥ 105 or<90 bpm vs those with 90-104 bpm, the hazard ratios of the primary end point were 2.233 (95% confidence interval, 1.250-3.989; P=.007) and 0.380 (95% confidence interval, 0.161-0.895; P=.027), respectively. Heart rate tended to decrease in the first 10 years after transplantation (P=.001). Patients with a net increase in heart rate during follow-up showed a higher incidence of adverse events. An elevated heart rate is an adverse prognostic marker after heart transplantation. Copyright © 2014 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

  8. Kiloparsec-scale Simulations of Star Formation in Disk Galaxies. IV. Regulation of Galactic Star Formation Rates by Stellar Feedback

    Energy Technology Data Exchange (ETDEWEB)

    Butler, Michael J. [Max Planck Institute for Astronomy, Königstuhl 17, D-69117 Heidelberg (Germany); Tan, Jonathan C. [Departments of Astronomy and Physics, University of Florida, Gainesville, FL 32611 (United States); Teyssier, Romain; Nickerson, Sarah [Institute for Computational Science, University of Zurich, 8049 Zurich (Switzerland); Rosdahl, Joakim [Leiden Observatory, Leiden University, P.O. Box 9513, NL-2300 RA Leiden (Netherlands); Van Loo, Sven [School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT (United Kingdom)

    2017-06-01

    Star formation from the interstellar medium of galactic disks is a basic process controlling the evolution of galaxies. Understanding the star formation rate (SFR) in a local patch of a disk with a given gas mass is thus an important challenge for theoretical models. Here we simulate a kiloparsec region of a disk, following the evolution of self-gravitating molecular clouds down to subparsec scales, as they form stars that then inject feedback energy by dissociating and ionizing UV photons and supernova explosions. We assess the relative importance of each feedback mechanism. We find that H{sub 2}-dissociating feedback results in the largest absolute reduction in star formation compared to the run with no feedback. Subsequently adding photoionization feedback produces a more modest reduction. Our fiducial models that combine all three feedback mechanisms yield, without fine-tuning, SFRs that are in excellent agreement with observations, with H{sub 2}-dissociating photons playing a crucial role. Models that only include supernova feedback—a common method in galaxy evolution simulations—settle to similar SFRs, but with very different temperatures and chemical states of the gas, and with very different spatial distributions of young stars.

  9. Heart rate changes during the Valsalva maneuver in patients with isolated aortic insufficiency

    Directory of Open Access Journals (Sweden)

    Navarro A.E.

    1997-01-01

    Full Text Available To determine the possible relationship between left ventricular dilatation and heart rate changes provoked by the Valsalva maneuver (Valsalva ratio, we studied 9 patients with isolated chronic aortic insufficiency. Left ventricular systolic function was assessed by two-dimensional echocardiography and cardiac catheterization. All patients were asymptomatic (functional class I of the New York Heart Association. The left ventricular internal diameters and volumes were significantly increased in all patients. The asymptomatic patients had either normal or slightly depressed ejection fraction (EF>0.40. The Valsalva ratio of these asymptomatic patients showed no significant correlation with the left ventricular volumes or with the left ventricular ejection fraction. In other words, parasympathetic heart rate control, as expressed by the Valsalva ratio, was normal in the asymptomatic patients with left ventricular dilatation and preserved left ventricular ejection fraction. Therefore, left ventricular dilatation may not be the major mechanism responsible for the abnormal parasympathetic heart rate control of patients with acquired heart disease

  10. Visibility graph analysis of heart rate time series and bio-marker of congestive heart failure

    Science.gov (United States)

    Bhaduri, Anirban; Bhaduri, Susmita; Ghosh, Dipak

    2017-09-01

    Study of RR interval time series for Congestive Heart Failure had been an area of study with different methods including non-linear methods. In this article the cardiac dynamics of heart beat are explored in the light of complex network analysis, viz. visibility graph method. Heart beat (RR Interval) time series data taken from Physionet database [46, 47] belonging to two groups of subjects, diseased (congestive heart failure) (29 in number) and normal (54 in number) are analyzed with the technique. The overall results show that a quantitative parameter can significantly differentiate between the diseased subjects and the normal subjects as well as different stages of the disease. Further, the data when split into periods of around 1 hour each and analyzed separately, also shows the same consistent differences. This quantitative parameter obtained using the visibility graph analysis thereby can be used as a potential bio-marker as well as a subsequent alarm generation mechanism for predicting the onset of Congestive Heart Failure.

  11. Level of agreement between heart rate variability and pulse rate variability in healthy individuals.

    Science.gov (United States)

    Bulte, Carolien S E; Keet, Sander W M; Boer, Christa; Bouwman, R Arthur

    2011-01-01

    According to international standards, autonomic function is assessed by heart rate variability (HRV) calculated from R-R intervals obtained with an electrocardiogram (ECG). However, intra-operative movement artefacts and electrical interference may complicate R-wave detection. Pulse rate variability (PRV) derived from continuous blood pressure measurements may provide a feasible alternative for HRV. We aimed to investigate the level of agreement between PRV and traditional HRV using a novel beat-to-beat non-invasive blood pressure monitoring device. In this prospective observational study, R-R intervals and non-invasive blood pressure waveforms were recorded simultaneously from 20 healthy male individuals at rest. HRV and PRV were analysed offline by spectral analysis, which divides the signal into its composing frequencies. Spearman's correlation coefficient, intra-class correlation coefficients and Bland-Altman analysis were used to study the level of agreement between HRV and PRV. The correlation coefficient between HRV and PRV was 0.99 (P blood pressure waveforms corresponds well with traditional HRV derived from ECG. These results indicate that under standard conditions, blood pressure waveforms may replace HRV in healthy individuals and that the use of PRV in the peri-operative setting should be further evaluated.

  12. [Effect of the hypothalamus on the diurnal rhythm of heart rate in the Rana temporaria].

    Science.gov (United States)

    Karmanova, I G; Belich, A I; Shilling, N V

    1983-01-01

    Computer treatment of the continuous row of R-R intervals of the ECG revealed the general pattern and masked periodicity of the diurnal dynamics of the heart rate in the frog Rana temporaria. It was found that in day time intact frogs exhibit tonic decrease of the heart rate with a maximum at about 12 a.m. At night, there is a tendency to tachycardia with a maximum at about 4 a.m. This periodicity of the heart rate is monitored mainly by the anterior and posterior hypothalamus.

  13. Fitbit Charge HR Wireless Heart Rate Monitor: Validation Study Conducted Under Free-Living Conditions.

    Science.gov (United States)

    Gorny, Alexander Wilhelm; Liew, Seaw Jia; Tan, Chuen Seng; Müller-Riemenschneider, Falk

    2017-10-20

    Many modern smart watches and activity trackers feature an optical sensor that estimates the wearer's heart rate. Recent studies have evaluated the performance of these consumer devices in the laboratory. The objective of our study was to examine the accuracy and sensitivity of a common wrist-worn tracker device in measuring heart rates and detecting 1-min bouts of moderate to vigorous physical activity (MVPA) under free-living conditions. Ten healthy volunteers were recruited from a large university in Singapore to participate in a limited field test, followed by a month of continuous data collection. During the field test, each participant would wear one Fitbit Charge HR activity tracker and one Polar H6 heart rate monitor. Fitbit measures were accessed at 1-min intervals, while Polar readings were available for 10-s intervals. We derived intraclass correlation coefficients (ICCs) for individual participants comparing heart rate estimates. We applied Centers for Disease Control and Prevention heart rate zone cut-offs to ascertain the sensitivity and specificity of Fitbit in identifying 1-min epochs falling into MVPA heart rate zone. We collected paired heart rate data for 2509 1-min epochs in 10 individuals under free-living conditions of 3 to 6 hours. The overall ICC comparing 1-min Fitbit measures with average 10-s Polar H6 measures for the same epoch was .83 (95% CI .63-.91). On average, the Fitbit tracker underestimated heart rate measures by -5.96 bpm (standard error, SE=0.18). At the low intensity heart rate zone, the underestimate was smaller at -4.22 bpm (SE=0.15). This underestimate grew to -16.2 bpm (SE=0.74) in the MVPA heart rate zone. Fitbit devices detected 52.9% (192/363) of MVPA heart rate zone epochs correctly. Positive and negative predictive values were 86.1% (192/223) and 92.52% (2115/2286), respectively. During subsequent 1 month of continuous data collection (270 person-days), only 3.9% of 1-min epochs could be categorized as MVPA according

  14. Effect of aerobic training on heart rate recovery in patients with established heart disease; a systematic review

    NARCIS (Netherlands)

    Snoek, J.A.; Berkel, S. van; Meeteren, N. van; Backx, F.J.G.; Daanen, H.A.M.

    2013-01-01

    Background: Although a delayed decrease in heart rate during the first minute after graded exercise has been identified as a powerful predictor of overall mortality in cardiac patients, the potential to influence this risk factor by aerobic training remains to be proven. Objective: The aim was to

  15. Nonlinear analysis of heart rate variability in patients with eating disorders

    NARCIS (Netherlands)

    Vigo, Daniel E.; Castro, Mariana N.; Dorpinghaus, Andrea; Weidema, Hylke; Cardinali, Daniel P.; Siri, Leonardo Nicola; Rovira, Bernardo; Fahrer, Rodolfo D.; Nogues, Martin; Leiguarda, Ramon C.; Guinjoan, Salvador M.

    2008-01-01

    Patients with anorexia nervosa or bulimia nervosa often have signs of autonomic dysfunction potentially deleterious to the heart. The aim of this study was to ascertain the nonlinear properties of heart rate variability in patients with eating disorders. A group of 33 women with eating disorders (14

  16. Heart Rate and Treatment Effect in Children with Disruptive Behavior Disorders

    Science.gov (United States)

    Stadler, Christina; Grasmann, Dorte; Fegert, Jorg M.; Holtmann, Martin; Poustka, Fritz; Schmeck, Klaus

    2008-01-01

    Objective: To examine whether