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1

Heart Rate and Exercise  

Science.gov (United States)

In this activity about heart health (on page 27 of the PDF), learners measure their heart rates after a variety of physical activities and compare the results with their resting heart rates, and with the heart rates of other learners in their groups. Learners also make predictions about their pulse rates. This lesson guide includes background information, setup and management tips, extension ideas, information about the heart in space and a handout.

Tharp, Barbara Z.; Erdmann, Deanne B.; Matyas, Marsha L.; Mcneel, Ronald L.; Moreno, Nancy P.

2009-01-01

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Target Heart Rate  

Science.gov (United States)

Students will practice how to calculate their Target Heart Rate to use during exercise routines. This will help students monitor the intensity of their workouts, and ultimately help them achieve results from their workout. Standard 2: Objective 2: a,b,c Before we discuss what the Target Heart Range is and how we can us it, we must first have some basic knowledge of the heart and it's functions. Click the "habits of the heart" to learn the basics of the heart and how it circulates blood throughout the body. Habits of the Heart The hearts ...

Peterson, Mr.

2011-09-18

3

Conclusion  

International Nuclear Information System (INIS)

In this chapter of book are present conclusions about work done by author, in particular that he found comparatively simple and available ways of synthesis of glycerin of acetylene line and glycerin of ethylen line which before was unknown or almost unknown in the chemical literature

1961-01-01

4

Conclusions  

Directory of Open Access Journals (Sweden)

Full Text Available In his conclusions on the general subject of “Turkey and the EU: Charting the Course Ahead”, the author points out the main challenges that Turkey and the EU must confront on their long road to integration, and he manifests the importance of building bridges, using all of the political resources available, as well as taking advantage of one of theprincipal resources of European governance: networks.

Francesc Morata

2006-11-01

5

Conclusion  

Directory of Open Access Journals (Sweden)

Full Text Available Articles of this special issue highlighted several different but complementary aspects linked to local and locally made products. The first part of the conclusion is directly oriented towards the concept of local food, its use and definition: local food is obviously a pluri-dimensional concept. The second part looks at the conceptual frameworks employed to deconstruct and understand the meaning of local food by various authors. In the third and final part we look again at the impact on and in...

Georgina Holt

2007-04-01

6

Multifractality and heart rate variability  

Science.gov (United States)

In this paper, we participate to the discussion set forth by the editor of Chaos for the controversy, ``Is the normal heart rate chaotic?'' Our objective was to debate the question, ``Is there some more appropriate term to characterize the heart rate variability (HRV) fluctuations?'' We focused on the ~24 h RR series prepared for this topic and tried to verify with two different techniques, generalized structure functions and wavelet transform modulus maxima, if they might be described as being multifractal. For normal and congestive heart failure subjects, the hq exponents showed to be decreasing for increasing q with both methods, as it should be for multifractal signals. We then built 40 surrogate series to further verify such hypothesis. For most of the series (~75%-80% of cases) multifractality stood the test of the surrogate data employed. On the other hand, series coming from patients in atrial fibrillation showed a small, if any, degree of multifractality. The population analyzed is too small for definite conclusions, but the study supports the use of multifractal series to model HRV. Also it suggests that the regulatory action of autonomous nervous system might play a role in the observed multifractality.

Sassi, Roberto; Signorini, Maria Gabriella; Cerutti, Sergio

2009-06-01

7

Heart rate in professional musicians  

Directory of Open Access Journals (Sweden)

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.

García Daniel

2008-07-01

8

Heart rate variability in healthy population  

International Nuclear Information System (INIS)

Background: Heart rate variability has been considered as an indicator of autonomic status. Little work has been done on heart rate variability in normal healthy volunteers. We aimed at evolving the reference values of heart rate variability in our healthy population. Methods: Twenty-four hour holter monitoring of 37 healthy individuals was done using Holter ECG recorder 'Life card CF' from 'Reynolds Medical'. Heart rate variability in both time and frequency domains was analysed with 'Reynolds Medical Pathfinder Digital/700'. Results: The heart rate variability in normal healthy volunteers of our population was found in time domain using standard deviation of R-R intervals (SDNN), standard deviation of average NN intervals (SDANN), and Square root of the mean squared differences of successive NN intervals (RMSSD). Variation in heart rate variability indices was observed between local and foreign volunteers and RMSSD was found significantly increased (p<0.05) in local population. Conclusions: The values of heart rate variability (RMSSD) in healthy Pakistani volunteers were found increased compared to the foreign data reflecting parasympathetic dominance in our population. (author)

2010-01-01

9

Vocalization of Heart Rate Variability.  

Science.gov (United States)

In this paper we have proposed vocalization of heart rate variability (HRV) as a perceptual analysis tool. We adapted a phonation-production model to encode external signals and generate audible representations of them. HRV changes caused by induced pertu...

S. Saliu A. Birand G. Kudaiberdieva

2001-01-01

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Dimensional Analysis of Heart Rate Variability in Heart Transplant Recipients.  

Science.gov (United States)

The authors discuss periodicities in the heart rate in normal and transplanted hearts. The authors then consider the possibility of dimensional analysis of these periodicities in transplanted hearts and problems associated with the record. (ERA citation 1...

J. P. Zbilut G. Mayer-Kress K. Geist

1987-01-01

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Heart rate recovery after exercise: relations to heart rate variability and complexity  

Directory of Open Access Journals (Sweden)

Full Text Available Physical exercise is associated with parasympathetic withdrawal and increased sympathetic activity resulting in heart rate increase. The rate of post-exercise cardiodeceleration is used as an index of cardiac vagal reactivation. Analysis of heart rate variability (HRV and complexity can provide useful information about autonomic control of the cardiovascular system. The aim of the present study was to ascertain the association between heart rate decrease after exercise and HRV parameters. Heart rate was monitored in 17 healthy male subjects (mean age: 20 years during the pre-exercise phase (25 min supine, 5 min standing, during exercise (8 min of the step test with an ascending frequency corresponding to 70% of individual maximal power output and during the recovery phase (30 min supine. HRV analysis in the time and frequency domains and evaluation of a newly developed complexity measure - sample entropy - were performed on selected segments of heart rate time series. During recovery, heart rate decreased gradually but did not attain pre-exercise values within 30 min after exercise. On the other hand, HRV gradually increased, but did not regain rest values during the study period. Heart rate complexity was slightly reduced after exercise and attained rest values after 30-min recovery. The rate of cardiodeceleration did not correlate with pre-exercise HRV parameters, but positively correlated with HRV measures and sample entropy obtained from the early phases of recovery. In conclusion, the cardiodeceleration rate is independent of HRV measures during the rest period but it is related to early post-exercise recovery HRV measures, confirming a parasympathetic contribution to this phase.

M. Javorka

2002-08-01

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Heart rate recovery after exercise: relations to heart rate variability and complexity  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Physical exercise is associated with parasympathetic withdrawal and increased sympathetic activity resulting in heart rate increase. The rate of post-exercise cardiodeceleration is used as an index of cardiac vagal reactivation. Analysis of heart rate variability (HRV) and complexity can provide use [...] ful information about autonomic control of the cardiovascular system. The aim of the present study was to ascertain the association between heart rate decrease after exercise and HRV parameters. Heart rate was monitored in 17 healthy male subjects (mean age: 20 years) during the pre-exercise phase (25 min supine, 5 min standing), during exercise (8 min of the step test with an ascending frequency corresponding to 70% of individual maximal power output) and during the recovery phase (30 min supine). HRV analysis in the time and frequency domains and evaluation of a newly developed complexity measure - sample entropy - were performed on selected segments of heart rate time series. During recovery, heart rate decreased gradually but did not attain pre-exercise values within 30 min after exercise. On the other hand, HRV gradually increased, but did not regain rest values during the study period. Heart rate complexity was slightly reduced after exercise and attained rest values after 30-min recovery. The rate of cardiodeceleration did not correlate with pre-exercise HRV parameters, but positively correlated with HRV measures and sample entropy obtained from the early phases of recovery. In conclusion, the cardiodeceleration rate is independent of HRV measures during the rest period but it is related to early post-exercise recovery HRV measures, confirming a parasympathetic contribution to this phase.

M., Javorka; I., Zila; T., Balhárek; K., Javorka.

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Increased heteroscedasticity of heart rate in fatal heart failure  

Science.gov (United States)

Healthy human heart rate is known to fluctuate in a highly complex manner, displaying complexity characteristics such as those shared by physical systems at a critical state. It is, however, widely believed that chronic heart failure reduces this complexity and that heart rate data from chronic-heart-failure patients can be used for the validation of complexity measures and paradigms applicable both to heart rate and more generally to assess any system's complexity. Here, we counter the above belief, showing an increase in fluctuations and in complexity of heart rate in chronic-heart-failure patients, in particular those at risk of death. This is supported by evidence of increased non-Gaussianity and heteroscedasticity resulting from the emergence of a characteristic correlation scale in the magnitude correlation landscape.

Struzik, Z. R.; Kiyono, K.; Hayano, J.; Watanabe, E.; Yamamoto, Y.

2008-04-01

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Heart Rate Variability – A Historical Perspective  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 contrib...

2011-01-01

15

Heart rate and heart rate variability, a pharmacological target.  

Science.gov (United States)

Heart rate varies with respiration, blood pressure, emotion, etc., and heart rate variability (HRV) is presently one of the best indices to predict fatal issues in cardiac failure and after myocardial infarction. HRV depends on various reflexes. In addition, parallel studies of HRV and the myocardial adrenergic and muscarinic transduction system in experimental models of cardiac hypertrophy (CH) have suggested that the myocardial phenotype at the sinus-node level may also play a role. A transgenic strain of mice with atrial overexpression of the beta 1-adrenergic receptors was generated with attenuated HRV, which demonstrates that the phenotype itself is a determinant of HRV. HRV is explored by noninvasive techniques, including simple determination of the standard error of the mean, time-domain analysis, and Fourier transformation. We recently developed a time and frequency domain method of analysis, the smoothed pseudo-Wigner-Ville transformation, which allows better exploration of nonstationarity. Nonlinear methods have also been applied due to the extreme complexity of the biological determinants, and have provided evidence of a chaotic attractor in certain conditions. It is proposed that in steady state a very simple process, which is not completely deterministic, could better explain intermit interval regulations than chaotic behavior. In contrast, under extreme circumstances the regulation proceeds using chaotic behavior. Arrhythmias and HRV can be quantitated in 16-month-old unanesthetized spontaneously hypertensive rats (SHR). Ventricular premature beats are more frequent in SHR than in age-matched controls; they disappear after converting enzyme inhibition (CEI) relative to the reduction of both cardiac hypertrophy and ventricular fibrosis. HRV is attenuated in SHR, as it is in compensatory CH in humans. When CH is prevented, HRV returns to normal. CEI is therefore antiarrhythmic. Another pharmacological application of this concept concerns the bradycardic agents that may improve HRV. PMID:9110110

Swynghedauw, B; Jasson, S; Chevalier, B; Clairambault, J; Hardouin, S; Heymes, C; Mangin, L; Mansier, P; Médigue, C; Moalic, J M; Thibault, N; Carré, F

1997-01-01

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Heart rate recovery and prognosis in heart failure patients  

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The aim of this study is to evaluate the usefulness of heart rate recovery (HRRec) for assessing risk of death in heart failure (HF) patients. Echocardiographic and clinical exercise data were analyzed retrospectively on 712 HF patients (EF ? 45%). HRRec was calculated as peak exercise heart rate – heart rate at 1 min of active recovery. Patients were followed for all-cause mortality (5.9 ± 3.3 years follow-up). Groups were identified according to HRRec: group-1 (HRR ? 4 bpm), group-2 ...

Kubrychtova, Vera; Olson, Thomas P.; Bailey, Kent R.; Thapa, Prabin; Allison, Thomas G.; Johnson, Bruce D.

2009-01-01

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Heart rate control during treadmill exercise.  

Science.gov (United States)

A computer-controlled treadmill and related data collection and processing systems have been developed for the control of heart rate during treadmill exercise. Minimizing deviations of heart rate from a preset profile is achieved by controlling the speed and/or the gradient of the treadmill. A simple and practical heart rate measurement algorithm has been developed to robustly measure the variations of heart rate. Both conventional Proportional-Integral-Derivative (PID) control and fuzzy Proportional-Integral (PI) control approaches have been employed for the controller design. The fuzzy Proportional-Integral algorithm achieved better heart rate tracking performance. Finally, a heart rate based exercising protocol was successfully implemented on the newly designed exercise system. PMID:17282738

Su, S W; Wang, L; Celler, B G; Savkin, A

2005-01-01

18

Heart rate variability in diastolic dysfunction and diastolic heart failure  

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Reduced heart rate variability (HRV) is associated with increased morbidity and mortality in patients with systolic heart failure (HF). So far available data regarding the prognostic significance of HRV in diastolic heart failure is insufficient. We prospectively analyzed HRV in pts. with diastolic dysfunction (DD) with or without diastolic HF. Pts. aged 50 to 85 years with at least one of the following diagnoses were included: arterial hypertension, diabetes mellitus, manifestation of athero...

2013-01-01

19

Effect of oxygen treatment on heart rate after abdominal surgery.  

DEFF Research Database (Denmark)

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. 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 oxygen saturation rate increased significantly from 96% to 99% (P < 0.0001) and the heart rate decreased significantly from 85 beats/min to 81 beats/min (P < 0.0001) during oxygen supplementation compared with air administered by a binasal catheter. The greatest decrease in heart rate occurred in patients with the lowest oxygen saturation or the highest heart rate values before oxygen supplementation. Overall, 73% of this unselected group of patients responded with decreased heart rate during supplemental oxygen therapy. No significant differences in changes in heart rate after oxygen 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 received routine postoperative care.

Rosenberg-Adamsen, S; Lie, C

1999-01-01

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Heart rate and heart rate variability responses to Tai Chi and jogging in Beijing and Graz  

Directory of Open Access Journals (Sweden)

Full Text Available Background: Tai Chi is a famous training method in China, and jogging is a popular kind of exercise both in Austria and China. Nevertheless, there is little information concerning online monitoring of biosignals during both training activities in parallel. Within the last years innovative scientific monitoring tools for evaluating features of neurocardial fitness have been developed. Aims: The goal of this study was to demonstrate heart rate and heart rate variability analysis for the first time during Tai Chi and jogging. Volunteers and Methods: Continuous electrocardiographic monitoring over a period of 75 minutes was performed simultaneously in two healthy volunteers using the same type of equipment (medilog AR12 systems. Two healthy persons (both male, 49 years and 52 years, respectively, both hobby sportsmen, were monitored continuously during two resting periods before and after active sport and also during Tai Chi and jogging, respectively. Results: Data acquisition was performed without any technical problems in both subjects. Poincaré plots of sequential R-R intervals (beat to beat variability show two ellipses of different shape and magnitude. During resting periods blood pressure effects can be clearly seen in one subject (jogging. The same effects, however reduced, are obvious in the other volunteer during Tai Chi. Conclusions: The present investigations during Tai Chi and jogging highlight the potential value of heart rate and heart rate variability monitoring even under difficult conditions. The innovative kind of analysis helps to show how well the human body reacts to sport, stress and recovery.

Gerhard Litscher

2011-02-01

 
 
 
 
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Heart Rate Variability Analysis in the Assessment of Autonomic Function in Heart Failure.  

Science.gov (United States)

Heart rate is not static but rather changes continuously in response to physical and mental demands. In fact, an invariant heart rate is associated with disease processes such as heart failure. Heart rate variability analysis is a noninvasive technique us...

M. J. De Jong D. C. Randall

2004-01-01

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Effect of yoga therapy on heart rate, blood pressure and cardiac autonomic function in heart failure.  

Science.gov (United States)

Background and Objective: It is well known that a hall mark of heart failure is adverse changes in autonomic function. Elevated blood pressure is a powerful predictor of congestive heart failure and other Cardiovascular Disease (CVD) outcomes. In this study, we planned to examine the effects of a 12 week yoga therapy on blood pressure, heart rate, heart rate variability, and rate pressure product (RPP). Methods: Out of 130 heart failure patients recruited for the study, 65 patients were randomly selected to receive 12 week yoga therapy along with standard medical therapy (yoga group). Other patients (n=65) received only standard medical therapy (control group). Heart rate, blood pressure, cardiac autonomic function (by short-term heart-rate variability analysis) and myocardial oxygen consumption (by RPP) were assessed before and after 12 weeks. In the yoga group, 44 patients and in the control group, 48 patients completed the study. Results: There was a significant decrease in heart rate, blood pressure and RPP in yoga group compared to control group. Also, LFnu and LF-HF ratio decreased significantly and HFnu increased significantly in yoga group compared to control group. Conclusion: Twelve-week yoga therapy significantly improved the parasympathetic activity and decreased the sympathetic activity in heart failure patients (NYHA I&II). PMID:24596712

Krishna, Bandi Hari; Pal, Pravati; G K, Pal; J, Balachander; E, Jayasettiaseelon; Y, Sreekanth; M G, Sridhar; G S, Gaur

2014-01-01

23

Volitional control of the heart rate.  

Science.gov (United States)

The heart rate is largely under control of the autonomic nervous system. The aim of the present study is to investigate the interactions between the brain and heart underlying volitional control of the heart and to explore the effectiveness of volition as a strategy to control the heart rate without biofeedback. Twenty seven healthy male subjects voluntarily participated in the study and were instructed to decrease and increase their heart beats according to rhythmic, computer generated sound either 10% faster or slower than the subjects' measured heart rate. Sympathetic and parasympathetic activities were estimated with the heart rate variability (HRV) obtained by power spectral analysis of RR intervals. Functional coupling patterns of cerebral cortex with the heart were determined by Partial directed coherence (PDC). In HR(slow) task; HR and sympathetic activity significantly decreased. However parasympathetic activity and power spectral density of EEG in low Alpha (8-10.5 Hz) band significantly increased. Moreover information flow from parietal area (P3 and P4) to RR interval significantly increased. During HR(quick) task; HR, sympathetic activity and power spectral density of EEG in low Beta (14-24 Hz) band significantly increased. Parasympathetic activity significantly decreased. Information flow from FT8, CZ and T8 electrodes to RR interval significantly increased. Our findings suggested that the heart beat can be controlled by volition and is related to some special areas in the cortex. PMID:23810994

Abukonna, Ahmed; Yu, Xiaolin; Zhang, Chong; Zhang, Jianbao

2013-11-01

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Heart Rate Variability-A Bibliographical Survey  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The study of heart rate variability (HRV) provides a mean for observing the heart?s ability to respond to normal regulatory signals that affect its rhythm. The HRV analysis has proven useful in diagnosis, treatment and monitoring of various pathologies. The modern field of HRV processing is extremely diverse, involving many areas like spectral estimation, system modeling, nonlinear dynamics and chaotic analysis, etc. With the recognition of significant relationship between the autonomi...

2008-01-01

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Metaiodobenzylguanidine and heart rate variability in heart failure  

International Nuclear Information System (INIS)

It is assumed that the low-frequency power (LF) of heart rate variability (HRV) increases with progress of congestive heart failure (CHF), therefore positively correlating with cardiac 123I-metaiodobenzylguanidine (MIBG) washout. It is demonstrated here that HRV, including normalized LF, correlated inversely with MIBG washout and positively with the ratio of heart-to-mediastinum MIBG activity in controls and CHF patients, whereas these correlations were not observed within CHF patients. Thus MIBG washout may increase and HRV including normalized LF may decrease with CHF, although the HRV and MIBG measures may not similarly change in proportion to the severity of the cardiac autonomic dysfunction in CHF. (author)

1998-10-01

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Metaiodobenzylguanidine and heart rate variability in heart failure  

Energy Technology Data Exchange (ETDEWEB)

It is assumed that the low-frequency power (LF) of heart rate variability (HRV) increases with progress of congestive heart failure (CHF), therefore positively correlating with cardiac {sup 123}I-metaiodobenzylguanidine (MIBG) washout. It is demonstrated here that HRV, including normalized LF, correlated inversely with MIBG washout and positively with the ratio of heart-to-mediastinum MIBG activity in controls and CHF patients, whereas these correlations were not observed within CHF patients. Thus MIBG washout may increase and HRV including normalized LF may decrease with CHF, although the HRV and MIBG measures may not similarly change in proportion to the severity of the cardiac autonomic dysfunction in CHF. (author)

Kurata, Chinori; Shouda, Sakae; Mikami, Tadashi; Uehara, Akihiko; Ishikawa, Keiko [Hamamatsu Univ., Shizuoka (Japan). School of Medicine; Tawarahara, Kei; Nakano, Tomoyasu; Matoh, Fumitaka; Takeuchi, Kazuhiko

1998-10-01

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Influence of heart failure severity on heart rate variability  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Introduction. Autonomic regulation of cardiovascular functions in congestive heart failure is characterised by enhanced sympathetic and diminished parasympathetic activity. The long term predominance of sympathetic tone is a significant factor in arrhythmogenesis, sudden cardiac death, and progressive pump failure. Heart rate variability (HRV) is a noninvasive method for estimating the sympatho vagal balance in cardiovascular control. Aim. The aim of this study was to analyse the influence of...

Zamaklar-Trifunovi? Danijela; Seferovi? Petar M.; Živkovi? Mirjana; Jeli? Vera; Vukomanovi? Goran; Petrovi? Milan; Mili? Nataša; Risti? Arsen D.; Simeunovi? Dejan

2005-01-01

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Erythrocyte sedimentation rate as a marker for coronary heart disease  

Directory of Open Access Journals (Sweden)

Full Text Available Josef YayanDepartment of Internal Medicine, Vinzentius Hospital, Landau, GermanyBackground: Patients with angina pectoris or myocardial infarction frequently present without evidence of cardiac-specific heart enzymes by laboratory analysis or specific pathologic electrocardiogram 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.Methods: 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.Results: 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%.Conclusion: Erythrocyte sedimentation rate may be a useful additional diagnostic criterion for coronary heart disease.Keywords: erythrocyte sedimentation rate, coronary heart disease, myocardial infarction, coronary angiography

Yayan J

2012-04-01

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Heart rate recovery after exercise: relations to heart rate variability and complexity  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Physical exercise is associated with parasympathetic withdrawal and increased sympathetic activity resulting in heart rate increase. The rate of post-exercise cardiodeceleration is used as an index of cardiac vagal reactivation. Analysis of heart rate variability (HRV) and complexity can provide useful information about autonomic control of the cardiovascular system. The aim of the present study was to ascertain the association between heart rate decrease after exercise and HRV parameters. He...

2002-01-01

30

Heart rate indication using musical data.  

Science.gov (United States)

Heart rate data reflects various physiological states such as biological workload, stress at work and concentration on tasks, drowsiness and the active state of the autonomic nervous system. This paper proposes system to indicate heart rate using musical data. Music changes physiological states for the better by relaxing people, or contributing to patient treatment through music therapy. Information in the form of music is advantageous because it does not hinder work as does verbal information and it contains more information than warning noises. We introduce and evaluate a prototype heart rate indication system and describe evaluation results of biofeedback effects on the worker during mental workload. The prototype system sequentially inputs the instantaneous heart rate into the computer, converts the data into musical instrument digital interface, the digital music format, and outputs it from the sound source. PMID:12083308

Yokoyama, Kiyoko; Ushida, Jun-ichiroh; Sugiura, Yasue; Mizuno, Mikako; Mizuno, Yasufumi; Takata, Kazuyuki

2002-07-01

31

Heart Rate and Electrocardiography Monitoring in Mice  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The majority of current cardiovascular research involves studies in genetically engineered mouse models. The measurement of heart rate is central to understanding cardiovascular control under normal conditions, with altered autonomic tone, superimposed stress or disease states, both in wild type mice as well as those with altered genes. Electrocardiography (ECG) is the “gold standard” using either hard wire or telemetry transmission. In addition, heart rate is measured or monitored from t...

2011-01-01

32

Heart Rate Variability Analysis in General Medicine  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Autonomic nervous system plays an integral role in homeostasis. Autonomic modulation can frequently be altered in patients with cardiac disorders as well as in patients with other critical illnesses or injuries. Assessment of heart rate variability is based on analysis of consecutive normal R-R intervals and may provide quantitative information on the modulation of cardiac vagal and sympathetic nerve input. The hypothesis that depressed heart rate variability may occur over a broad range of i...

2003-01-01

33

Heart rate variability analysis in general medicine  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Autonomic nervous system plays an integral role in homeostasis. Autonomic modulation can frequently be altered in patients with cardiac disorders as well as in patients with other critical illnesses or injuries. Assessment of heart rate variability is based on analysis of consecutive normal R-R intervals and may provide quantitative information on the modulation of cardiac vagal and sympathetic nerve input. The hypothesis that depressed heart rate variability may occur over a broad range of i...

2003-01-01

34

Heart rate variability in left ventricular hypertrophy.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

BACKGROUND--Electrocardiographic left ventricular hypertrophy and strain are associated with increased cardiac morbidity and mortality. Impaired cardiac autonomic function, assessed non-invasively by spontaneous heart rate variability on Holter monitoring, is associated with an increased risk of sudden death after myocardial infarction. AIM--To study the effect of left ventricular hypertrophy on heart rate variability. PATIENTS--36 controls and 154 patients with left ventricular hypertrophy (...

Mandawat, M. K.; Wallbridge, D. R.; Pringle, S. D.; Riyami, A. A.; Latif, S.; Macfarlane, P. W.; Lorimer, A. R.; Cobbe, S. M.

1995-01-01

35

Electrocardiographic pill for cattle heart rate determination.  

Science.gov (United States)

Decreased agricultural profit margins and recent bioterrorism concerns have led to an increased interest in monitoring livestock health. Heart rate and core body temperature are traditional vital parameters for cattle health assessment, as they provide warnings for illness and disease. However, obtaining these data in the field is time and labor intensive, which speaks to the need for solutions that provide continuous and automatic acquisition of these parameters. This paper presents the design of a pill that can remain in an animal's reticulum and use electrocardiographic techniques to ascertain heart rate. The wired prototype has been tested with a fistulated steer. These tests demonstrate that consistent heart vector data can be acquired even in the presence of animal movement and rumination. After minor processing, these signals are suitable for use with peak detection circuitry that can automate heart rate determination. PMID:19163803

Warren, Steve; Martinez, Angel; Sobering, Timothy; Andresen, Daniel

2008-01-01

36

Ear Acupressure, Heart Rate, and Heart Rate Variability in Patients with Insomnia  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This high-tech “teleacupuncture study” describes a neurovegetative ear acupressure effect in patients with chronic insomnia by using heart rate variability analysis. Heart rate (HR) and heart rate variability (HRV) measurements in 31 patients (mean age?±?SD: 54.3?±?10.6 years) were performed under standardized conditions in Harbin, China, and the data analysis was performed in Graz, Austria. Similar to our previous clinical and basic teleacupuncture research works, the electroca...

Wang, Lu; Cheng, Weiping; Sun, Zhongren; Xu, Yangyang; Cheng, Guangyu; Gaischek, Ingrid; Kuang, Haixue; Litscher, Gerhard

2013-01-01

37

Gaussian Mixture Model of Heart Rate Variability  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 m...

Costa, Tommaso; Boccignone, Giuseppe; Ferraro, Mario

2012-01-01

38

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 le...

Karlsson, Bjo?rn-markus; Lindkvist, Marie; Lindkvist, Markus; Karlsson, Marcus; Lundstro?m, Ronnie; Ha?kansson, Stellan; Wiklund, Urban; Den Berg, Johannes

2012-01-01

39

Heart Rate Variability - A Historical Perspective  

Directory of Open Access Journals (Sweden)

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.

GeorgeEBillman

2011-11-01

40

Heart Rate Conditioning in Newborn Infants: Relationships Among Conditionability, Heart Rate Variability, and Sex  

Science.gov (United States)

Trace conditioning was evaluated in newborn infants by measurements of heart rate responses to a conditioned stimulus in anticipation of or in absence of the unconditioned stimulus. Data suggest females have higher levels of heart rate variability than males, which parallels their greater conditionability. (GO)

Stamps, Leighton E.; Porges, Stephen W.

1975-01-01

 
 
 
 
41

Heart rate variability in assessment of clinical status, functional conditions and prognosis in heart failure  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Data about heart rate variability analysis in healthy people and patients with chronic heart failure are reviewed. Prognostic value of time-domain and spectral measures is mentioned. Influence of standard therapy on heart rate variability is described.

2006-01-01

42

Heart rate variability and its relation to ventricular arrhythmias in congestive heart failure.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

BACKGROUND--It has been shown that heart rate variability is decreased in patients with congestive heart failure and that depressed heart rate variability is associated with a propensity to ventricular arrhythmias. Little is known, however, about heart rate variability in patients with both congestive heart failure and ventricular arrhythmias. METHODS--Spectral heart rate variability was analysed from 24 hour ambulatory electrocardiograms in 15 controls, 15 patients with non-sustained ventric...

1994-01-01

43

Wireless monitoring of Heart Rate using Microcontroller  

Directory of Open Access Journals (Sweden)

Full Text Available This paper describes the development of wireless monitoring of a heart rate based on a microcontroller. We can record the ECG signals and Heart beats of all patients in a single computer. These biomedical signals are acquired and then processed with a microcontroller. After processing, all data are sent to a communication interface that can send this information to a personal computer. For the patient suffering from the cardiac disease it is very necessary to perform accurate and quick diagnosis. For this purpose a continuous monitoring of the ECG signal, patient’s current heart rate and BP are essential. We can monitor the patient’s ECG signal by using Bluetooth transmission and reception in the central place in any hospital. The MATLAB software is used to simulate the ECG waveform.

J.S. Prasath

2013-02-01

44

Information scaling properties of heart rate variability.  

Science.gov (United States)

Many chaos detection methods have proven inherently ambiguous in that they yield similar results for chaotic signals and correlated noise. The purpose of this work was to determine whether human resting heart period sequences have global properties characteristic of chaotic systems. We investigated the inherent global organization of heart period sequences by quantifying how the information content of the embedded sequences varied as a function of scale. We compared the information scaling characteristics of 60-min heart period sequences obtained from 10 healthy resting volunteers with those obtained from numerous periodic and chaotic control sequences. The information scaling properties of the heart period sequences were significantly different from those obtained for the controls, particularly at the coarsest scales (P = 0.0003 vs. low-dimensional periodic controls; P = 0.0005 vs. low-dimensional chaotic controls; P = 0.0003 vs. low-dimensional periodic and chaotic controls). We also showed that nondeterministic components, such as large tachycardic (or bradycardic) events or aperiodic fluctuations, can lead to scaling characteristics similar to those observed for the resting heart period sequences. This, in addition to previous evidence from spectral, nonlinear predictability and lexical studies, favors an events-based approach to understanding heart rate variability. PMID:9841524

Roach, D E; Sheldon, R S

1998-06-01

45

Effect of early bereavement on heart rate and heart rate variability.  

Science.gov (United States)

Early bereavement is associated with increased cardiovascular events. The mechanism, however, has not been well studied. We assessed whether bereavement is associated with an increased heart rate (HR) and decreased heart rate variability that might contribute to increased cardiovascular risk. A total of 78 bereaved spouses and parents (55 women and 23 men; aged 34 to 87 years, mean 65) were studied with 24-hour Holter monitoring within 2 weeks of bereavement (acute) and at 6 months. Their findings were compared to those from a nonbereaved reference group (52 women and 27 men) aged 33 to 91 years (mean 63.6). All participants were in sinus rhythm. We assessed the mean HR, atrial and ventricular arrhythmias, and both time and frequency domain heart rate variability measures. Acute bereavement was associated with increased 24-hour HR (mean ± SE, 75.1 ± 1.1 vs 70.7 ± 1.0; p = 0.004) and reduced heart rate variability, as indicated by lower standard deviation of the NN intervals index (median 45.4 vs 49.9, p = 0.017), total power (7.78 ± 0.10 vs 8.02 ± 0.09, p = 0.03), very low frequency (7.23 ± 0.09 vs 7.44, p = 0.046) and low frequency (5.76 ± 0.12 vs 6.16 ± 0.09, p = 0.01). At 6 months, the bereaved had a significantly lower HR (p = 0.001) and increased standard deviation of the NN intervals index (p = 0.02), square root of the mean square of differences of successive intervals (p = 0.045), number of interval differences of successive NN intervals >50 ms divided by the number of NN intervals (p = 0.039), low-frequency power (p = 0.02), and high frequency (p = 0.002) compared to the initial acute levels. In conclusion, the present study, the first to report 24-hour HR monitoring in the early weeks of bereavement, has demonstrated increased HR and altered autonomic function that might contribute to the increased cardiovascular events in early bereavement. PMID:22853984

Buckley, Thomas; Stannard, Angela; Bartrop, Roger; McKinley, Sharon; Ward, Christopher; Mihailidou, Anastasia Susie; Morel-Kopp, Marie-Christie; Spinaze, Monica; Tofler, Geoffrey

2012-11-01

46

Music determines heart rate variability of singers  

Directory of Open Access Journals (Sweden)

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.

RebeckaJörnsten

2013-07-01

47

Streaming updates for heart rate variability algorithms.  

Science.gov (United States)

Heart rate variability (HRV) quantifies the fluctuations of the lengths of consecutive heart beat intervals, and is a reliable descriptor of many physiological factors modulating the normal rhythm of the heart. As the heart rate signal is nonstationary, indicators deduced from it may be present at all times, but may also occur episodically at nonpredetermined time instances. The potential for real-time feedback long-term ambulatory recordings is thus apparent. Numerous methods for measuring HRV have been standardized and are in active use, but are typically not designed to operate at real time. In this paper, we study the most popular HRV quantification methods and propose streaming algorithms that maximally utilize previously computed information without altering the output of the methods. We demonstrate speedups of more than two orders of magnitude for typical use-case scenarios. Using our algorithms on embedded systems that compute HRV leads to dramatic decreases in power consumption and in some cases allows for computation of metrics that were not previously possible at real time. PMID:24956611

Stergiou, Stergios; Balakrishnan, Rajalakshmi

2014-07-01

48

Heart rate and heart rate variability responses to Tai Chi and jogging in Beijing and Graz  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Background: Tai Chi is a famous training method in China, and jogging is a popular kind of exercise both in Austria and China. Nevertheless, there is little information concerning online monitoring of biosignals during both training activities in parallel. Within the last years innovative scientific monitoring tools for evaluating features of neurocardial fitness have been developed. Aims: The goal of this study was to demonstrate heart rate and heart rate variability analysis for the first t...

Gerhard Litscher; Weibo Zhang; Tao Huang; Lu Wang

2011-01-01

49

Effects of aerobic training on heart rate  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Regular physical exercise is an important factor to reduce the indexes of cardiovascular and all causes morbimortality. However, there is, apparently, additional and independent benefits of the regular practice of physical exercise and the improvement of the level of aerobic condition. Heart rate (H [...] R) is mediated primarily by the direct activity of the autonomic nervous system (ANS), specifically through the sympathetic and parasympathetic branches activities over the sinus node autorhythmicity, with predominance of the vagal activity (parasympathetic) at rest, that is progressively inhibited since the onset of the exercise. The HR behavior has been widely studied during different conditions and protocols associated to the exercise. A reduction of the cardiac vagal tone (parasympathetic function) and consequently a diminished HR variability in rest, independently of the protocol of measurement used, is related to an autonomic dysfunction, chronic-degenerative diseases and increased mortality risk. Individuals with high levels of aerobic condition have a lower resting HR, along with a larger parasympathetic activity or smaller sympathetic activity, but it is not necessarily a direct consequence of the exercise training, as long as other inherent adaptations to the aerobic conditioning can influence the resting HR. The HR response in the onset of the exercise represents the integrity of the vagus nerve, and the HR recovery on the post-exercise transient also denotes important prognostic information; by the way, individuals that have a slow HR recovery in the first minute post-exercise have increased mortality risk. In conclusion, the physiological mechanisms modulating HR during or after an exercise program are not totally clear, and further studies are needed.

Almeida, Marcos B.; Araújo, Claudio Gil S..

50

Effects of aerobic training on heart rate  

Directory of Open Access Journals (Sweden)

Full Text Available Regular physical exercise is an important factor to reduce the indexes of cardiovascular and all causes morbimortality. However, there is, apparently, additional and independent benefits of the regular practice of physical exercise and the improvement of the level of aerobic condition. Heart rate (HR is mediated primarily by the direct activity of the autonomic nervous system (ANS, specifically through the sympathetic and parasympathetic branches activities over the sinus node autorhythmicity, with predominance of the vagal activity (parasympathetic at rest, that is progressively inhibited since the onset of the exercise. The HR behavior has been widely studied during different conditions and protocols associated to the exercise. A reduction of the cardiac vagal tone (parasympathetic function and consequently a diminished HR variability in rest, independently of the protocol of measurement used, is related to an autonomic dysfunction, chronic-degenerative diseases and increased mortality risk. Individuals with high levels of aerobic condition have a lower resting HR, along with a larger parasympathetic activity or smaller sympathetic activity, but it is not necessarily a direct consequence of the exercise training, as long as other inherent adaptations to the aerobic conditioning can influence the resting HR. The HR response in the onset of the exercise represents the integrity of the vagus nerve, and the HR recovery on the post-exercise transient also denotes important prognostic information; by the way, individuals that have a slow HR recovery in the first minute post-exercise have increased mortality risk. In conclusion, the physiological mechanisms modulating HR during or after an exercise program are not totally clear, and further studies are needed.

Marcos B. Almeida

2003-04-01

51

Modeling heart rate variability by stochastic feedback  

Science.gov (United States)

We consider the question of how the cardiac rhythm spontaneously self-regulates and propose a new mechanism as a possible answer. We model the neuroautonomic regulation of the heart rate as a stochastic feedback system and find that the model successfully accounts for key characteristics of cardiac variability, including the 1/ f power spectrum, the functional form and scaling of the distribution of variations of the interbeat intervals, and the correlations in the Fourier phases which indicate nonlinear dynamics.

Amaral, Luís. A. Nunes; Goldberger, Ary L.; Ivanov, Plamen Ch.; Stanley, H. Eugene

52

Modeling heart rate variability by stochastic feedback  

Science.gov (United States)

We consider the question of how the cardiac rhythm spontaneously self-regulates and propose a new mechanism as a possible answer. We model the neuroautonomic regulation of the heart rate as a stochastic feedback system and find that the model successfully accounts for key characteristics of cardiac variability, including the 1/f power spectrum, the functional form and scaling of the distribution of variations of the interbeat intervals, and the correlations in the Fourier phases which indicate nonlinear dynamics.

Amaral, L. A.; Goldberger, A. L.; Stanley, H. E.

1999-01-01

53

Heart Rate Variability in Obstructive Sleep Apnea.  

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Introduction: Obstructive Sleep Apnea (OSA) is characterized by repeated episodes of upper airway obstruction leading to increased airway resistance and respiratory effort, producing oxygen desaturation, hypercapnia and central nervous system arousal. The intermittent hypoxemia and carbon-dioxide retention is responsible for the changes in autonomic and hemodynamic responses to sleep. Heart rate variability (HRV) is a marker of autonomic activity and can be analyzed using...

Selvakumar Jagannathan; Cruz, Suzanne Maria D.; Valarmathy Selvakumar; Vishwanatha Rao Badanidiyur

2013-01-01

54

Doppler Radar for Heartbeat Rate and Heart Rate Variability Extraction  

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This paper presents a Doppler radar system used to detect the heartbeat signal from a d?istance of one meter. The proposed system is based on using a vector network analyzer and two antennas. Measurements are performed at 16 GHz for different power levels between 0 and -25 dBm. Both heartbeat rate and heart rate variability are extracted and compared to a simultaneous ECG signal.

Obeid, Dany; Sadek, Sawsan; Zaharia, Gheorghe; El Zein, Ghai?s

2011-01-01

55

Heart rate and physical activity patterns in persons with profound intellectual and multiple disabilities.  

Science.gov (United States)

Because physical fitness and health are related to physical activity, it is important to gain an insight into the physical activity levels of persons with profound intellectual and multiple disabilities (PIMD). The purpose of this study was to examine heart rate patterns to measure the activity levels of persons with PIMD and to analyze these heart rate patterns according to participant characteristics, observed level of activity, days, and time of day. The heart rate patterns of 24 participants with PIMD were measured continuously using a heart rate monitor for 8 h · d for a period of 6 days. Physical activity levels were measured with questionnaires. Data were analyzed using multilevel analysis. The results indicate that the participants use only 32% of their heart rate reserve over 6 days. The intensity of heart rate reserve ranged from 1 to 62%. On a given day, wide ranges in heart rates between participants and within persons were observed. Between days, only small ranges in the heart rate were found. The participants could be grouped into 4 classes according to their heart rate. In addition, factors such as time of day, physical activity, and age are significantly related to heart rate patterns. In conclusion, this study is an important first step in exploring activity patterns based on heart rate patterns in persons with PIMD. The participants used relatively small fractions of their heart rate reserves. Time of day and age appear to have a considerable influence on heart rate patterns. The observed classes in heart rate patterns suggest that other probably more personal and psychosocial factors have significant influences on heart rate patterns, as well. PMID:23442278

Waninge, Aly; van der Putten, Annette A J; Stewart, Roy E; Steenbergen, Bert; van Wijck, Ruud; van der Schans, Cees P

2013-11-01

56

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

DEFF Research Database (Denmark)

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 Copenhagen, Frederiksberg, Denmark. 2. Novo Nordic A/S, Maaloev, Denmark. 3. Department of Clinical Sciences, Swedish University of Agricultural Science, Uppsala, Sweden. Heart rate variability (HRV) is an indirect measurement of the autonomic modulation of heart rate (HR). Reduced HRV measured from short-time electrocardiography is seen in dogs with heart failure (HF) secondary to myxomatous mitral valve disease (MMVD). However, HRV is suggested to increase with disease severity at early stages of MMVD. The aims of this study were 1) to associate HR and HRV with severity of MMVD in Cavalier King Charles Spaniels (CKCS) and 2) to compare HR and HRV between CKCS and other dog breeds in a group of dogs in HF secondary toMMVD. One-hundred dogs were examined by echocardiography and 24-hour electrocardiography. The dogs were divided into five groups: 1) CKCS with no/minimal mitral regurgitation (MR) (MR jet=15% of the left atrial area using color Doppler mapping) and no murmur, 2) CKCS with mild MR (20%50%) and no clinical signs of HF, 4) CKCS in HF (HF defined as left atrium to aortic root ratio (LA/Ao) >1.5, clinical signs of HF and furosemide responsiveness) and 5) non-CKCS in HF. Dogs in HF were allowed HF therapy. Both HR and HRV were analysed over a 24-hour period, while HRV were also analysed over a 6-hour nightly period. Analyses of variance were performed with HR or HRV as response variables and the explanatory variables dog group and echocardiographic indices of MMVD were included separately. All P-values were Bonferroni corrected. Minimum- and mean HR were significantly higher in CKCS with moderate/severe MR and in HF compared to CKCS with no/minimal and mild MR (all P<0.001). Seven out of 26 HRV variables were significantly decreased in CKCS with moderate/severe MR and in HF compared to CKCS with no/minimal and mild MR (all P<0.02). Another 10 HRV variables showed the same groupwise differences (all P<0.02), except that the difference between CKCS with mild MR and CKCS with moderate/severe MR did not reach statistical significance. Minimum HR, mean HR and the HRV variables (7 and 10) differing between dog groups, also consistently decreased with increasing MR, LA/Ao and the proximal isovelocity surface area in CKCS. Non-CKCS in HF had a lower minimum HR compared to CKCS in HF (P=0.03) and a higher triangular index measured in both periods (all P<0.04). In conclusion, HR increased and most HRV variables decreased with increasing severity of MMVD in CKCS, even prior to the development of HF. Other breeds in HF secondary to MMVD had lower minimum HR, but higher triangular index compared to CKCS in HF.

Rasmussen, Caroline Elisabeth; Falk, Bo Torkel

2011-01-01

57

Adjusting heart rate during sleep using activity variance.  

Science.gov (United States)

In order to mimic the natural decrease in heart rate that occurs during sleep, an algorithm was devised to decrease the base rate to a programmable sleep rate. The algorithm was developed using activity and sinus rate data obtained from 18 normal subjects ranging in age from 22-80 years. The data were recorded in the event record of a "taped-on" pacemaker. The surface ECG signal was used to inhibit a pacer programmed to VVI at 45 ppm. The ECG documented the sinus rate while the accelerometer-based activity signals were recorded in an event record. An algorithm was used to estimate the smoothed acceleration variance every 26 seconds. The activity variance was stored in a histogram. Results: The lower 7/24ths of the histogram entries were primarily attributable to sleep. If the activity variance was entered into the lower 7/24ths of the histogram and the accelerometer reading was below rate responsive threshold, the base rate was switched to sleep rate. Using least mean squares to estimate optimal slope, base rate, and sleep rate, the root mean square error between activity derived heart rate and sinus rate was 12 beats/min. Conclusion: This study supports using an estimate of activity variance to automatically decrease pacing rate below programmed base rate. This decrease may be actuated during an afternoon nap or nighttime sleep. PMID:7845794

Bornzin, G A; Arambula, E R; Florio, J; Levine, P A; Hauck, G

1994-11-01

58

Heart rate variability in left ventricular dysfunction and heart failure: effects and implications of drug treatment.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 probability of survival. Because drug treatment in these patients has rapidly changed over the past two decades, the effect of these drugs on heart rate variability needs special attention. DESIGN--A study o...

Tuininga, Y. S.; Veldhuisen, D. J.; Brouwer, J.; Haaksma, J.; Crijns, H. J.; Man In T Veld, A. J.; Lie, K. I.

1994-01-01

59

Effects of Hemoglobin Concentration on Heart Rate Variability  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Context: Previous studies reported decreased heart rate variability (HRV) among subjects with anemia. However, the underlying pathology of anemia may be the direct cause of low HRV which may preclude fromdrawing the conclusion that anemia per se causes diminished HRV. Aim: To detect the relationship between hemoglobin concentrations and HRV. Setting and Design: It was a cross-sectional case-control laboratorybased study. Patients and Methods: The study involved 25 apparently healthy males and...

2011-01-01

60

Intermittency in Human Heart Rate Variability  

International Nuclear Information System (INIS)

Intermittency in time series of the time intervals between heart beats (RR intervals) extracted from 24 hour (portable) ECG is found for some cases of humans with arrhythmia. Laminar phases are found by sweeping a short (5 intervals) time window through the time series and calculating the standard deviation of the series in each window. 8 of the 18 arrhythmia cases studied had a bimodal distribution of the standard deviation values indicating some kind of intermittency. The distribution of lengths of the laminar phases identifies the intermittency obtained in human heart rate variability as Type 1 in the Pomeau and Manneville classification. Although the arrhythmia cases studied were medically very different - in those instances that intermittency did occur the probability distributions of laminar phase lengths were strikingly similar. (author)

2001-05-01

 
 
 
 
61

Time Domain Measures Of Heart Rate Variability In Heavy Workers  

Directory of Open Access Journals (Sweden)

Full Text Available Background: Physical inactivity and low resting heart rate variability (HRV are associated with increased incidence of coronary heart disease. Heavy physical activity is associated with higher heart rate variability and reduces the risk of coronary heart diseaseObjective: To assess some time domain measures of HRV in order to compare Cardiac Autonomic Function between sedentary and heavy workers.Methods: This cross sectional study was carried out in the Department of Physiology, Bangabandhu Sheikh Mujib Medical University between 1st July 2008 to 30th June 2009 on 30 apparently healthy heavy workers aged 28-50 years from low socioeconomic condition (study group. For comparison 30 age, sex, BMI and socioeconomic status matched apparently healthy sedentary subjects (group A were also studied. The study subjects were selected among rickshaw-pullers living in the slum areas nearby BSMMU, Dhaka and the controls were from fourth class employee of BSMMU, Dhaka. Heart Rate Variability were assessed by a Polygraph. Several time domain measures of HRV such as mean R-R interval, mean HR, SDNN, RMSSD were analyzed. For statistical analysis, Independent-Samples t-test, and Pearson’s correlation coefficient tests were done as applicable.Results: Resting mean heart rate (P<0.01, SDNN (P<0.01 and RMSSD (P<0.001 were significantly lower but mean R-R interval (P<0.001 was significantly higher in heavy workers than those of sedentary control. The mean R-R interval (P<0.05 showed significant positive correlation in heavy workers but significant negative correlation in sedentary workers with BMI.Conclusion: Cardiac autonomic nerve function status may be higher with parasympathetic dominance by increased physical activity.

Taskina Ali

2011-12-01

62

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

Directory of Open Access Journals (Sweden)

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.

Hasanpour Mir Mahsa

2012-12-01

63

Heart rate overshoot in running events.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The phenomenon of heart rate overshoot has been examined in 6 high-school athletes aged 15-16 years and in 8 university athletes aged 19-20 years. The incidence was 100% over distances of 50, 100 and 200 metres, and only one subject failed to show an overshoot following a 400 metre run. However, the overshoot was relatively larger and more long-lived following the shorter runs. While an accumulation of anaerobic metabolites seems the most likely explanation of the phenomenon over the longer d...

Yamaji, K.; Shephard, R. J.

1986-01-01

64

Heart rate variability in childhood obesity.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Obesity is characterized by hemodynamic and metabolic alterations. Autonomic control on cardiac function involvement is controversial. The aim of the study was to assess early sign of cardiac autonomic dysfunction in obesity, using time- and frequency-domain heart rate variability (HRV) analysis in a pediatric population. METHODS: 32 obese children (OB) (17 M, 15 F; 13.9 +/- 1.7 y) were compared with 13 healthy lean subjects (7 M, 6 F; 12.9 +/- 1.6 y). For each participant, the authors perfor...

2001-01-01

65

Impaired heart rate recovery indices in psoriasis patients  

Science.gov (United States)

Background Psoriasis is a systemic inflammatory disease associated with increased risk of cardiovascular diseases. The heart rate recovery index (HRRI) is an indicator of autonomic nervous system function and is an independent prognostic risk factor for cardiovascular diseases. The aim of this study was to evaluate the heart rate recovery indices in patients with psoriasis. Material/methods Thirty-three psoriasis patients (22 male; mean age 41±11 years) and 26 healthy individuals (15 male; mean age 39±11 years) as a control group were included in the study. Baseline electrocardiography, transthoracic echocardiographic examinations, and exercise stress tests were performed in psoriasis and control groups. The heart rate recovery of the psoriasis group at 1, 2, 3, 4, and 5 minutes after maximal exercise were calculated and compared to those of the control group. Results Baseline demographic and clinical characteristics of psoriasis and control groups including age, sex, body mass index, systolic blood pressure, and echocardiographic parameters were similar. Total cholesterol, low-density lipoprotein cholesterol, and triglyceride levels were significantly higher and high-density lipoprotein cholesterol levels were significantly lower in the psoriasis group (p<0.05). Heart rate recovery at 1, 2, 3, 4, and 5 minutes after maximal exercise were found to be significantly lower in the psoriasis group (p<0.05). Additionally, baseline heart rates before exercise were significantly higher in the psoriasis group (p<0.05). Conclusions We found that impaired HRRI in psoriasis patients, which indicates the underlying autonomic nervous system dysfunction, is a pathophysiologic mechanism for increased cardiovascular disease risk.

Yuksel, Esra Pancar; Yuksel, Serkan; Yenercag, Mustafa; Soylu, Korhan; Aydin, Fatma; Senturk, Nilgun; Yucel, Huriye; Canturk, Tayyar; Turanli, Ahmet Y.

2014-01-01

66

Impaired heart rate recovery indices in psoriasis patients.  

Science.gov (United States)

Background Psoriasis is a systemic inflammatory disease associated with increased risk of cardiovascular diseases. The heart rate recovery index (HRRI) is an indicator of autonomic nervous system function and is an independent prognostic risk factor for cardiovascular diseases. The aim of this study was to evaluate the heart rate recovery indices in patients with psoriasis. Material and Methods Thirty-three psoriasis patients (22 male; mean age 41±11 years) and 26 healthy individuals (15 male; mean age 39±11 years) as a control group were included in the study. Baseline electrocardiography, transthoracic echocardiographic examinations, and exercise stress tests were performed in psoriasis and control groups. The heart rate recovery of the psoriasis group at 1, 2, 3, 4, and 5 minutes after maximal exercise were calculated and compared to those of the control group. Results Baseline demographic and clinical characteristics of psoriasis and control groups including age, sex, body mass index, systolic blood pressure, and echocardiographic parameters were similar. Total cholesterol, low-density lipoprotein cholesterol, and triglyceride levels were significantly higher and high-density lipoprotein cholesterol levels were significantly lower in the psoriasis group (pHeart rate recovery at 1, 2, 3, 4, and 5 minutes after maximal exercise were found to be significantly lower in the psoriasis group (p<0.05). Additionally, baseline heart rates before exercise were significantly higher in the psoriasis group (p<0.05). Conclusions We found that impaired HRRI in psoriasis patients, which indicates the underlying autonomic nervous system dysfunction, is a pathophysiologic mechanism for increased cardiovascular disease risk. PMID:24584215

Pancar Yuksel, Esra; Yuksel, Serkan; Yenercag, Mustafa; Soylu, Korhan; Aydin, Fatma; Senturk, Nilgun; Yucel, Huriye; Canturk, Tayyar; Turanli, Ahmet Yasar

2014-01-01

67

Gender differences of heart rate variability in healthy volunteers  

International Nuclear Information System (INIS)

Objective: To identify the basic values of heart rate variability in Pakistani population and to verify our hypothesis that there are gender differences in cardiovascular autonomic modulation. Methods: The descriptive cross sectional study based on convenience probability sampling was conducted at Armed Forces Institute of Cardiology/National Institute of Heart Diseases (AFIC/NIHD) Pakistan. The duration of the study was from December 2009 to July 2010. It involved 24-hour holter monitoring of 45 healthy individuals using holter electrocardiography (ECG) recorder. Heart rate variability was analysed in time (SDNN, SDANN, SDNNi, rMSSD, pNN50) and frequency domains (power, VLF, LF, and HF). Results: The time domain indices; SDNN (male=140 +- 36 ms vs. females=122 +- 33 ms; p =0.09), SDANN (male=123 +- 34 ms vs. females=111+- 34 ms; P= 0.23), SDNNi (male=64 +-19 ms vs. females=52 +- 14 ms; P= 0.03), and pNN50 (male=14 +- 10 ms vs. females=12 +- 7 ms; P= 0.43) were decreased in female volunteers when compared with males. Comparison of frequency domain indices; Total power (male=4041 +- 3150 ms/sup 2/ vs. females=2750 +- 1439 ms/sup 2/; P= 0.07), VLF (male=291 2675 ms/sup 2/ vs. females=1843 +- 928 ms/sup 2/; P= 0.06), LF (male=788 +- 397 ms/sup 2/ vs. females=556 +- 346 ms/sup 2/; P= 0.04) and HF (male=318 +- 251 ms/sup 2/ vs. females=31 277 ms/sup 2/; P= 0.94) amongst males and females showed attenuated heart rate variability in females. Of all the observed values, SDNNi and LF were found significantly (p <0.05) decreased in women. Conclusion: In healthy population, heart rate variability is low in women than men. It reflects sympathetic dominance in women in our population. (author)

2012-05-01

68

General anesthesia suppresses normal heart rate variability in humans  

Science.gov (United States)

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.

Matchett, Gerald; Wood, Philip

2014-06-01

69

Controlling the emotional heart: Heart rate biofeedback improves cardiac control during emotional reactions  

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When regulating negative emotional reactions, one goal is to reduce physiological reactions. However, not all regulation strategies succeed in doing that. We tested whether heart rate biofeedback helped participants reduce physiological reactions in response to negative and neutral pictures. When viewing neutral pictures, participants could regulate their heart rate whether the heart rate feedback was real or not. In contrast, when viewing negative pictures, participants could regulate heart ...

2014-01-01

70

Study of Heart Rate and Heart Rate Variability during Rapid Decompression to 50,000 FT.  

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A previous study of the heart rate (HR) response to positive pressure breathing (PPB), anxiety and hypoxia during rapid decompression (RD) revealed a consistent pattern in the beat-to-beat or interbeat interval variability of HR, known in the literature a...

C. S. Chopp J. B. Bomar J. A. Dellinger

1994-01-01

71

Drug Effects on Heart Rate and Heart Rate Variability During a Prolonged Reaction Task.  

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The effects of an amphetamine and a barbiturate on heart rate were investigated during long term performance (three hours in a serial reaction task). Besides the interbeat interval (IBI) derived from the successive R-tops of the ECG, the variability of IB...

A. W. K. Gaillard D. A. Trumbo A. J. Krul

1975-01-01

72

Time Domain Measures Of Heart Rate Variability In Heavy Workers  

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Background: Physical inactivity and low resting heart rate variability (HRV) are associated with increased incidence of coronary heart disease. Heavy physical activity is associated with higher heart rate variability and reduces the risk of coronary heart diseaseObjective: To assess some time domain measures of HRV in order to compare Cardiac Autonomic Function between sedentary and heavy workers.Methods: This cross sectional study was carried out in the Department of Physiology, Bangabandhu ...

2011-01-01

73

Heart rate variability in patients with systemic sclerosis  

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Objectives. Heart rate variability depends on the state of the autonomic nervous system as well as on the state of heart muscle. It may be possible that some signs or symptoms of the heart involvement in systemic sclerosis patients result from the recently recognized autonomic nervous system manifestations. Methods. Heart rate variability was determined by an integral computer-based standard system in 18 patients with systemic sclerosis (but only the results of 15 patients were statistically ...

Sielan?czyk, Andrzej W.; Jagodzin?ski, Leszek; Gmyrek, Joanna; Goz?dzik, Joanna; Kucharz, Eugene J.

2007-01-01

74

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

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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.

Kasermann Hans P

2007-08-01

75

Heart rate and vasomotor control during exercise.  

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Spontaneous baroreflex function and vascular changes were assessed in young adults during dynamical mild exercise. Windkessel time constant was assessed by two different methods: two-element windkessel model, and by an autoregressive (AR) model, while the baroreflex sensitivity (BRS, ms/mmHg) was assessed by the sequence method. Results showed a change in the baroreflex control of heart rate (HR) with the severity of exercise, as well as the resetting phenomenon. Methods used to estimate the windkessel time constant were poorly correlated. Subject by subject correlation was found between the BRS and the time constant derived from the AR model within exercise and recovery period. These results may suggest that reflex mechanisms controlling HR may also participate in controlling peripheral circulation or, viceversa, BRS is influenced by vascular tone. PMID:18002022

Vallais, Frederic; Baselli, Giuseppe; Lucini, Daniela; Pagani, Massimo

2007-01-01

76

Global Heart Failure Rates and Erythropoietin  

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Full Text Available Global variation in heart failure (HF prevalence and mortality rates is evident and multiple factors have been hypothesised to explain such non-random distribution. The author hypothesised that this non-random HF distribution could be attributed, in part, to individual variation in the level of erythropoietin (EPO, a hormone and a possible cardioprotectant. Such individual EPO variation can be explained by hypoxia resulting from regional differences in geographic elevation. This hypothesis was justified using results from various animal-based and clinical studies. In addition, data from the population-based Healthcare Cost and Utilization Project was used. The global distribution of HF can be explained, in part, by the geographic landscape. Prospective studies based on the author’s hypothesis may provide new treatment opportunities for such an important health issue as HF. In addition, this hypothesis may demonstrate new insights into the mechanism of HF.

Rovshan M. Ismailov

2012-07-01

77

Procedural Pain Heart Rate Responses in Massaged Preterm Infants  

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Heart rate (HR) responses to the removal of a monitoring lead were assessed in 56 preterm infants who received moderate pressure, light pressure or no massage therapy. The infants who received moderate pressure massage therapy exhibited lower increases in HR suggesting an attenuated pain response. The heart rate of infants who received moderate pressure massage also returned to baseline faster than the heart rate of the other two groups, suggesting a faster recovery rate.

Diego, Miguel A.; Field, Tiffany; Hernandez-reif, Maria

2009-01-01

78

Ordinal pattern statistics for the assessment of heart rate variability  

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The recognition of all main features of a healthy heart rhythm (the so-called sinus rhythm) is still one of the biggest challenges in contemporary cardiology. Recently the interesting physiological phenomenon of heart rate asymmetry has been observed. This phenomenon is related to unbalanced contributions of heart rate decelerations and accelerations to heart rate variability. In this paper we apply methods based on the concept of ordinal pattern to the analysis of electrocardiograms (inter-peak intervals) of healthy subjects in the supine position. This way we observe new regularities of the heart rhythm related to the distribution of ordinal patterns of lengths 3 and 4.

Graff, G.; Graff, B.; Kaczkowska, A.; Makowiec, D.; Amigó, J. M.; Piskorski, J.; Narkiewicz, K.; Guzik, P.

2013-06-01

79

Heart rate variability study of childhood anxiety disorders  

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Background: The current study aims at assessment of heart rate variability among children and adolescents with childhood anxiety disorder, using the case-control design. Materials and Methods: The study was carried out at a tertiary care multispecialty hospital. It included 34 children and adolescents with diagnosis of childhood anxiety disorder, in the age range of eight to eighteen years, and 30 age- and sex-matched healthy controls. Heart-rate variability was studied using the standard protocol. Results: Significantly reduced variability of the heart rate was observed in both the time as well as frequency domains in the disorder group as compared to the control group. These findings indicate decreases in the sympathetic and parasympathetic activity in the disorder group, thus representing diminished physiological variability at rest. Conclusions: The notion of autonomic inflexibility, as seen in the current study, has important implications for stability in biological systems. The loss of variability in the physiological systems in general, and in the cardiovascular system in particular, has an association with a number of diseases and dysfunctions.

Sharma, Rajiv Kumar; Balhara, Yatan Pal Singh; Sagar, Rajesh; Deepak, K. K.; Mehta, Manju

2011-01-01

80

Heart Rate Variability in Patients with Rheumatoid Arthritis  

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Full Text Available Background: Altered cardiovascular autonomic nerve function with impaired sympathovagal balance is found in rheumatoid arthritis (RA. Heart Rate Variability (HRV analysis is an important tool for assessment of autonomic nerve activity.Objective: To assess cardiac autonomic nerve function status in patients with Rheumatoid arthritis (RA by time domain measures of HRV.Methods: This cross sectional study was conducted in the Department of Physiology, Bangabandhu Sheikh Mujib Medical University (BSMMU, Dhaka from January to December 2010. Sixty female RA patients, age range 18-50 years were constituted study group enrolled from the Out- patient Rheumatology Wing, Department of Medicine, BSMMU. Age matched thirty apparently healthy females were studied as control. Time domain measures of Heart Rate Variability (HRV such as Mean RR intervals, Mean HR, SDNN, RMSSD, NN50% and PNN 50% were recorded for 5 minutes by a Polygraph machine to observe cardiac autonomic nerve function activity. Data were analyzed by independent sample t test.Results: Mean R-R interval, SDNN, RMSSD, PNN50%, NN50% were significantly lower (p<0.001 but heart rate was significantly (P<0.001 higher in rheumatoid arthritis patients.Conclusion: Cardiac autonomic nerve function is impaired and characterized by reduced resting parasympathetic activity in female Rheumatoid Arthritis patients.

Kawser Jahan, Noorzahan Begum, Sultana Ferdousi

2012-12-01

 
 
 
 
81

Controlling the emotional heart: heart rate biofeedback improves cardiac control during emotional reactions.  

Science.gov (United States)

When regulating negative emotional reactions, one goal is to reduce physiological reactions. However, not all regulation strategies succeed in doing that. We tested whether heart rate biofeedback helped participants reduce physiological reactions in response to negative and neutral pictures. When viewing neutral pictures, participants could regulate their heart rate whether the heart rate feedback was real or not. In contrast, when viewing negative pictures, participants could regulate heart rate only when feedback was real. Ratings of task success paralleled heart rate. Participants' general level of anxiety, emotion awareness, or cognitive emotion regulation strategies did not influence the results. Our findings show that accurate online heart rate biofeedback provides an efficient way to down-regulate autonomic physiological reactions when encountering negative stimuli. PMID:24373886

Peira, Nathalie; Fredrikson, Mats; Pourtois, Gilles

2014-03-01

82

AUTONOMIC CONTROL OF HEART RATE AFTER EXERCISE IN TRAINED WRESTLERS  

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The objective of this study was to establish differences in vagal reactivation, through heart rate recovery and heart rate variability post exercise, in Brazilian jiu-jitsu wrestlers (BJJW). A total of 18 male athletes were evaluated, ten highly trained (HT) and eight moderately trained (MT), who performed a maximum incremental test. At the end of the exercise, the R-R intervals were recorded during the first minute of recovery. We calculated heart rate recovery (HRR60s), and performed linear...

2013-01-01

83

Heart Rate Turbulence as Risk-Predictor after Myocardial Infarction  

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Heart rate turbulence (HRT) is the baroreflex-mediated short-term oscillation of cardiac cycle lengths after spontaneous ventricular premature complexes. HRT is composed of a brief heart rate acceleration followed by a gradual heart rate deceleration. In high risk patients after myocardial infarction (MI) HRT is blunted or diminished. Since its first description in 1999 HRT emerged as one of the most potent risk factors after MI. Predictive power of HRT has been studied in more than 10,000 po...

Zuern, Christine S.; Barthel, Petra; Bauer, Axel

2011-01-01

84

Host and environmental determinants of heart rate and heart rate variability in four European populations  

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OBJECTIVE: In a population-based sample of nuclear families recruited in the framework of the European Project on Genes in Hypertension (EPOGH), we investigated the association between heart rate (HR) and its variability (HRV), and gender, age, posture, breathing frequency, body mass index, systolic blood pressure, family history of hypertension and various lifestyle factors, such as smoking, alcohol and coffee consumption and physical activity. METHODS: RR interval and respiration were regis...

2003-01-01

85

The genetic contribution to heart rate and heart rate variability in quiescent mice  

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Recent studies have suggested a genetic component to heart rate (HR) and HR variability (HRV). However, a systematic examination of the genetic contribution to the variation in HR and HRV has not been performed. This study investigated the genetic contribution to HR and HRV using a wide range of inbred and recombinant inbred (RI) mouse strains. Electrocardiogram data were recorded from 30 strains of inbred mice and 29 RI strains. Significant differences in mean HR and total power (TP) HRV wer...

2008-01-01

86

Heart rate differences between right and left unilateral electroconvulsive therapy.  

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Left and right unilateral electrode placements were alternately applied in electroconvulsive therapy given to 21 men with melancholia. Accompanying heart rate elevations were greater following right unilateral treatment than left unilateral, apparently because of longer persistence of peak rates. This is consistent with right cerebral hemisphere superiority in the control of heart rate activity in neurologically intact humans.

Swartz, C. M.; Abrams, R.; Lane, R. D.; Dubois, M. A.; Srinivasaraghavan, J.

1994-01-01

87

Predictors of abnormal heart rate recovery in patients with heart failure reduced and preserved ejection fraction.  

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BACKGROUND: Heart rate recovery (HRR) is becoming an important prognostic maker in heart failure (HF), but very little is known about the underlying mechanisms responsible for its clinical efficacy. Therefore, we examined echocardiographic and exercise (submaximal and maximal) characteristics to gain a better appreciation of HRR and factors responsible for the development of abnormal HRR in patients with both heart failure reduced ejection fraction (HFrEF) and heart failure preserved ejection fraction (HFpEF). METHODS: Cardiopulmonary exercise testing (CPX), a 6-minute walk test (6MWT), and resting 2D echocardiography were randomly performed in 240 HF patients (200 HFrEF, 40 HFpEF) after which HRR was measured. HRR was defined as the difference between heart rate at peak exercise and 1?minute following test termination. RESULTS: Bivariate correlation analyses found significant relationships among most CPX and 6MWT measurements with the highest correlations between 6MWT HRR and 6MWT peak HR (r?=?0.65; p?CONCLUSIONS: HRR after both CPX and the 6MWT is significantly related to many exercise and echocardiographic measures with the most significant predictors of abnormal HRR being related to indices of cardiorespiratory performance in patients with HFrEF and HFpEF. PMID:23335654

Cahalin, Lawrence P; Arena, Ross; Labate, Valentina; Bandera, Francesco; Guazzi, Marco

2013-03-11

88

Variations in circadian heart rate in psychiatric disorders: theoretical and practical implications  

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Full Text Available HG Stampfer,1 SB Dimmitt2 1School of Psychiatry and Clinical Neurosciences, University of Western Australia, 2School of Medicine and Pharmacology, University of Western Australia, Crawley, WA, AustraliaBackground: Data are presented to demonstrate dimensions of variation in circadian heart rate in patients under treatment for a psychiatric disorder and to comment on their clinical relevance.Method: Serial recordings of 24-hour heart rates were obtained from individuals under treatment for a psychiatric disorder and from healthy volunteers.Results: The mean 24-hour heart rate can vary independently of the circadian rate pattern or “rate architecture.” Sleep and waking heart rate can vary independently. Variations in circadian heart rate are state-dependent: broadly different clinical states are associated with distinctly different patterns of circadian heart rate, particularly during sleep.Conclusion: Different regulatory mechanisms or pathways are involved in mediating different aspects of circadian heart rate. An analysis of circadian heart rate can contribute useful physiological adjunct information to psychiatric assessment and the monitoring of patient response to treatment.Keywords: anxiety, depression, neuroendocrine regulation

Stampfer HG

2013-04-01

89

Heart rate turbulence and variability in patients with ventricular arrhythmias  

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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

Diego Tarricone

2009-08-01

90

Heart Rate Variability Analysis in Different Age and Pathological Conditions  

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Full Text Available Problem statement: Heart Rate Variability (HRV has been used as a measure of mortality primarily with patients who had undergone cardiac surgery. The analysis of Heart Rate Variability (HRV demands specific capabilities which are not provided either by parametric or nonparametric conventional estimation methods. The Empirical Mode Decomposition (EMD adaptively estimates the Intrinsic Mode Functions (IMFs of nonlinear nonstationary signals. Approach: The intrinsic mode functions estimated from the HRV signal were based on local characteristics of the signal. The principle objective was to analyze the HRV latencies of healthy subjects in different age and pathological conditions. The method was applied to HRV signal of 17 healthy young control subjects, 17 healthy old control subjects and 20 congestive heart failure patients for half hour duration. Results: The results showed that a healthy person?s HRV rapidly rises to its maximum response much earlier than the HRV of pathological subjects. The rising slope of the time scale?s plot discriminates the healthy controls and pathological subjects with 100% sensitivity and specificity. Conclusion: This fact makes the method a promising approach to be applied in clinical practice as a screening test for specific risk-groups.

M. E.S. Chelladurai

2011-01-01

91

Study Heart Rate by Tools from Complex Networks  

International Nuclear Information System (INIS)

Heart rate measured as beat-to-beat time intervals varies in time. It is believed that time intervals between subsequent normal heart contractions carry information about the regulatory system of the heart. How to quantify such signals is not clear and because of that heart rate variability is still apart from the clinic routine. In the following, we propose a method for representing a heart rate signal as a directed network. Then we study the signal properties by complex network tools. The signals to study were collected from patients recovering after the heart transplantation. The aim is to classify the progress of adapting of the new heart - graft. Moreover, it is expected that the method allows for visual classification. Our investigations are preliminary, however the obtained results are promising. (authors)

2010-06-16

92

Variation in heart rate influences the assessment of transient ischemic dilation in myocardial perfusion scintigraphy  

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Full Text Available Abstract Background Transient arrhythmias can affect transient ischemic dilation (TID ratios. This study was initiated to evaluate the frequency and effect of normal heart rate change on TID measures in routine clinical practice. Methods Consecutive patients undergoing stress/rest sestamibi gated myocardial perfusion scintigraphy were studied (N = 407. Heart rate at the time of stress and rest imaging were recorded. TID ratios were analyzed in relation to absolute change in heart rate (stress minus rest for subjects with normal perfusion and systolic function (Group 1, N = 169 and those with abnormalities in perfusion and/or function (Group 2, N = 238. Results In Group 1, mean TID ratio was inversely correlated with the change in heart rate (r = -0.47, P Conclusion Normal variation in heart rate between the stress and rest components of myocardial perfusion scans is common and can influence TID ratios in patients with normal and abnormal cardiac scans.

Levin Daniel P

2007-01-01

93

The influence of respiratory pattern on heart rate variability analysis in heart failure  

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Introduction. Autonomic dysfunction is present early in the course of heart failure, and has a direct role on deterioration of cardiac function and prognosis. Heart rate variability (HRV) estimates sympathovagal control of heart frequency. The influence of respiratory pattern on HRV is clinically important. Breathing disorders are common in heart failure and highly affect HRV and autonomic evaluation. It was previously shown that slow and deep breathing increased parasympathetic tone, but eff...

Zamaklar-Trifunovi? Danijela; Seferovi? Petar M.; Petrovi? Milan; Živkovi? Mirjana; Vukomanovi? Goran; Mili? Nataša; Risti? Arsen D.; Zdravkovi? Marija

2007-01-01

94

Heart Rate and Cardiovascular Disease: An Alternative to Beta Blockers  

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Ivabradine, an If inhibitor, acts primarily on the sinoatrial node and is used to reduce the heart rate with minimal effect on myocardial contractility, blood pressure, and intracardiac conduction. Heart rate reduction is an important aspect of care in patients with chronic stable angina and heart failure. Many patients with coronary artery disease have coexisting asthma or chronic obstructive airway disease, and most of them are unable to tolerate beta blockers. Ivabradine may thus be a usef...

Liang, Michael; Puri, Aniket; Devlin, Gerard

2009-01-01

95

Heart-Rate Recovery Index Is Impaired in Behçet's Disease  

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Behçet's disease, a multisystemic inflammatory disorder, has been associated with a number of cardiovascular dysfunctions, including ventricular arrhythmias and sudden cardiac death. Heart-rate recovery after exercise can provide both an estimate of impaired parasympathetic tone and a prognosis in regard to all-cause and cardiovascular death. The aim of our study was to evaluate heart-rate recovery in Behçet's disease

Kaya, Ergun Baris; Yorgun, Hikmet; Akdogan, Ali; Ates, Ahmet Hakan; Canpolat, Ugur; Sunman, Hamza; Aytemir, Kudret; Tokgozoglu, Lale; Kabakci, Giray; Calguneri, Meral; Ozkutlu, Hilmi; Oto, Ali

2009-01-01

96

The Predictive Value of Resting Heart rate Following Osmotherapy in Brain injury: Back to Basics  

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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

Mahsa Hasanpour Mir

2012-12-01

97

Conventional heart rate variability analysis of ambulatory electrocardiographic recordings fails to predict imminent ventricular fibrillation  

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OBJECTIVES. The purpose of this report was to study heart rate variability in Holter recordings of patients who experienced ventricular fibrillation during the recording. BACKGROUND. Decreased heart rate variability is recognized as a long-term predictor of overall and arrhythmic death after myocardial infarction. It was therefore postulated that heart rate variability would be lowest when measured immediately before ventricular fibrillation. METHODS. Conventional indexes of heart rate variability were calculated from Holter recordings of 24 patients with structural heart disease who had ventricular fibrillation during monitoring. The control group consisted of 19 patients with coronary artery disease, of comparable age and left ventricular ejection fraction, who had nonsustained ventricular tachycardia but no ventricular fibrillation. RESULTS. Heart rate variability did not differ between the two groups, and no consistent trends in heart rate variability were observed before ventricular fibrillation occurred. CONCLUSIONS. Although conventional heart rate variability is an independent long-term predictor of adverse outcome after myocardial infarction, its clinical utility as a short-term predictor of life-threatening arrhythmias remains to be elucidated.

Vybiral, T.; Glaeser, D. H.; Goldberger, A. L.; Rigney, D. R.; Hess, K. R.; Mietus, J.; Skinner, J. E.; Francis, M.; Pratt, C. M.

1993-01-01

98

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

Directory of Open Access Journals (Sweden)

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.

CatharinaCorneliaGrant

2013-11-01

99

Decreased heart rate variability is associated with poststroke depression  

Science.gov (United States)

Objective Although decreased heart rate variability (HRV) has been well documented in association with depression following myocardial infarction, this phenomenon has not been studied in patients with stroke. The present study was designed to prospectively assess HR in relationship to depression among patients with acute stroke. Design Using 24 hour Holter monitoring, assess HRV. Setting A large university rehabilitation hospital. Participants patients, with first ever stroke and no other severe physical illness, cigarette smoking or drug therapy that could affect HRV, were evaluated over 24 hours for heart rate variability. Measurements Patients were evaluated using the Structured Clinical Interview for depression diagnosis. Severity was assessed by Hamilton Depression Rating Scale. Stroke severity was assessed by the NIH Stroke Scale, the Barthel Index and the Mini Mental State Exam. The standard deviation of time in msec between normal heart beats (SDNN) was the primary measure of HRV. Results Among patients with poststroke major or minor depression (N=33), the SDNN was 109±32.6 SD compared with nondepressed patients (N=16) whose SDNN was 133.9±40.1 SD(Wilcoxon rank test S=492, p=0.048). The SDNN was significantly and independently related to the existence of depression, but no other intergroup differences. Conclusions These findings, for the first time, have provided some evidence that both major and minor poststroke depression may lead to decreased HRV. Future research in larger groups of patients should determine whether other measures of HRV more specific to sympathetic-parasympathetic tone are decreased in patients with poststroke depression.

Spalletta, Gianfranco; Jorge, Ricardo E.; Bassi, Andrea; Colivicchi, Furio; Ripa, Alessandra; Caltagirone, Carlo

2008-01-01

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The effect of metaprolol alone and metaprolol plus bromazepam on heart rate and heart rate variability during multislice computed tomography angiography  

International Nuclear Information System (INIS)

Objective: The purpose of this study was to determine the effect of metaprolol alone and metaprolol plus bromazepam on heart rate and heart rate variability during multi slice computed tomography (MSCT) angiography. Methodology: This was a Double blind randomized controlled trial was conducted at AFIC/NIHD, Rawalpindi, from May 2011 to November 2011. Patients undergoing first MSCT angiography meeting inclusion criteria with heart rates (HR) more than 80 beats/min were included. Patients were randomized in to two groups using random numbers table. Group 1 was administered metaprolol plus placebo while group 2 was administered metaprolol plus bromazepam one hour before the scan. Both groups had scans under strictly similar conditions. HR before and during scan along with heart rate variability (HRV) were recorded. Results: A total of 80 patients were included. Patients mean age was 49 + 13, 57 % were males while 43 % were females. Risk factor profile was similar in both groups. HR reduction in group 1 was 15+ 6.0 and in group 2, was 21+9.0 (p= 0.002). HRV in group 1 was 3.9 + 1.32 and in group 2 was 2.3 + 1.0 (p= 0.003). Group 2 had significantly lower HR and significantly less HRV as compared with group 1. Conclusion: Combination of bromazepam and metaprolol results in significant and further reduction in heart rate and heart rate variability than metaprolol alone. Both drugs can be used together for a better control of heart rate and heart rate variability during MSCT angiography for improving the quality of images. (author)

2012-01-01

 
 
 
 
101

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

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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: ?-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. ?-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.

GeorgeEBillman

2013-08-01

102

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

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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. PMID:24128278

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

2014-07-01

103

Heart rate variability and turbulence analysis in patients with psoriasis  

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Full Text Available Objectives: Psoriasis vulgaris (PV is a chronic inflammatory skin disorder with increased incidence of many systemic abnormalities. However, the effects of psoriasis on autonomic nervous system have not been previously well-defined. Impaired autonomic function with an increase in sympathetic activity may be associated with ventricular arrhythmias and sudden cardiac death in the general population. Heart rate turbulence (HRT is a noninvasive test to reflect the increased sympathetic tone and abnormal baroreflex sensitivity. The aim of current study was to investigate the effect of psoriasis on cardiac autonomic function by using HRT and heart rate variability (HRV parameters as possible indicators of increased risk for ventricular arrhythmias and sudden cardiac death.Materials and methods: The study comprised 20 psoriatic patients without cardiovascular involvement and age and sex matched 20 healthy subjects. The severity of the disease was evaluated by the “Psoriasis Area and Severity Index”. The HRV and turbulence analysis were assessed from a 24-hour Holter recording.Results: There were no statistically significant differences between the two groups with respect to clinical, demographic and biochemical characteristics. When HRT parameters were compared; the values of the turbulence onset and slope in psoriatic patients were not significantly different from the control group (p>0.05. HRV parameters except for high frequency power (significantly lower in psoriatic patients, p0.05.Conclusion: Psoriasis appeared not to be associated with impaired autonomic function regarding to HRT and HRV values. Further investigations are needed to confirm these results

Asuman Biçer

2010-12-01

104

[Association between level of intelligence and heart rate variability].  

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Earlier we discovered that heart rate variability was associated with the level of intelligence. The purpose of this study is to confirm this association using more reliable method and to define more precisely the frequency band within which the amplitude of the heart rate modulations is related to intelligence. 13 males (aged 14 to 17) were the study subjects. The total score of the computer game Tetris was taken as a general measure of the intelligence level. Heart rate was recorded electrocardiographically both at rest and during playing Tetris. Frequency analysis of heart rate was carried out with digital Fourier transformation. Correlation analysis showed that there was positive association between the level of intelligence and the amplitude of heart rate modulation at the frequencies 0.30 and 0.15 modulations per RR interval. This association is closer for the heart rate at rest than for the heart rate during mental work and for the frequency 0.30 than for the 0.15 modulations per RR interval. PMID:21961308

Mukhin, V N; Iakovlev, N M

2011-08-01

105

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

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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 rate (RHR). The relationships between HRT parameters and the prognosis of CHF patients were determined. Results 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. Conclusions 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.

2014-01-01

106

A New Approach to Detect Congestive Heart Failure Using Short-Term Heart Rate Variability Measures  

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Heart rate variability (HRV) analysis has quantified the functioning of the autonomic regulation of the heart and heart's ability to respond. However, majority of studies on HRV report several differences between patients with congestive heart failure (CHF) and healthy subjects, such as time-domain, frequency domain and nonlinear HRV measures. In the paper, we mainly presented a new approach to detect congestive heart failure (CHF) based on combination support vector machine (SVM) and three nonstandard heart rate variability (HRV) measures (e.g. SUM_TD, SUM_FD and SUM_IE). The CHF classification model was presented by using SVM classifier with the combination SUM_TD and SUM_FD. In the analysis performed, we found that the CHF classification algorithm could obtain the best performance with the CHF classification accuracy, sensitivity and specificity of 100%, 100%, 100%, respectively.

Wang, Qian; Zhou, GuangMin; Wang, Ying; Jiang, Qing

2014-01-01

107

Heart rate turbulence as risk-predictor after myocardial infarction  

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Full Text Available Heart Rate Turbulence (HRT is the baroreflex-mediated short-term oscillation of cardiac cycle lengths after spontaneous ventricular premature complexes (VPC. HRT is composed of a brief heart rate acceleration followed by a gradual heart rate deceleration. In high risk patients after myocardial infarction (MI HRT is blunted or diminished. Since its first description in 1999 HRT emerged as one of the most potent risk factors after MI. Predictive power of HRT has been studied in more than 10,000 post-infarction patients. This review is intended to provide an overview of HRT as risk predictor after MI.

ChristineStefanieZuern

2011-12-01

108

Heart Rate Recovery in Asymptomatic Patients with Chagas Disease  

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Background Chagas disease patients with right bundle-branch block (RBBB) have diverse clinical presentation and prognosis, depending on left ventricular (LV) function. Autonomic disorder can be an early marker of heart involvement. The heart rate recovery (HRR) after exercise may identify autonomic dysfunction, with impact on therapeutic strategies. This study was designed to assess the HRR after symptom-limited exercise testing in asymptomatic Chagas disease patients with RBBB without ventricular dysfunction compared to patients with indeterminate form of Chagas disease and healthy controls. Methods One hundred and forty-nine subjects divided into 3 groups were included. A control group was comprised of healthy individuals; group 1 included patients in the indeterminate form of Chagas disease; and group 2 included patients with complete RBBB with or without left anterior hemiblock, and normal ventricular systolic function. A symptom-limited exercise test was performed and heart rate (HR) response to exercise was assessed. HRR was defined as the difference between HR at peak exercise and 1 min following test termination. Results There were no differences in heart-rate profile during exercise between healthy individuals and patients in indeterminate form, whereas patients with RBBB had more prevalence of chronotropic incompetence, lower exercise capacity and lower HRR compared with patients in indeterminate form and controls. A delayed decrease in the HR after exercise was found in 17 patients (15%), 9% in indeterminate form and 24% with RBBB, associated with older age, worse functional capacity, impaired chronotropic response, and ventricular arrhythmias during both exercise and recovery. By multivariable analysis, the independent predictors of a delayed decrease in the HRR were age (odds ratio [OR] 1.11; 95% confidence interval [CI] 1.03 to 1.21; p?=?0.010) and presence of RBBB (OR 3.97; 95% CI 1.05 to 15.01; p?=?0.042). Conclusions A small proportion (15%) of asymptomatic Chagas patients had attenuated HRR after exercise, being more prevalent in patients with RBBB compared with patients in indeterminate form and controls.

de Alencar, Maria Clara Noman; Rocha, Manoel Otavio da Costa; Lima, Marcia Maria de Oliveira; Costa, Henrique Silveira; Sousa, Giovane Rodrigo; Carneiro, Renata de Carvalho Bicalho; Silva, Guilherme Canabrava Rodrigues; Brandao, Fernando Vieira; Kreuser, Lucas Jordan; Ribeiro, Antonio Luiz Pinho; Nunes, Maria Carmo Pereira

2014-01-01

109

Heart rate and heart rate variability in pregnant warmblood and Shetland mares as well as their fetuses.  

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Heart rate (HR) is an important parameter of fetal well-being. In horses, HR and heart rate variability (HRV) can be determined by fetomaternal electrocardiography (ECG) from mid-pregnancy to foaling. Normal values for physiological parameters in larger breeds are often used as reference values in ponies. However, HR increases with decreasing size of the animal and in ponies is higher than in warmblood horses. It is not known if fetal HR is affected by breed and if values obtained in larger breeds can be used to assess Shetland fetuses. We have determined fetomaternal beat-to-beat (RR) interval (inversely correlated to HR) and HRV in warmblood (n=6) and Shetland pregnancies (n=7) at days 280 and 300 of gestation by ECG. Maternal RR interval was lower in pony than in warmblood mares (day 280: Shetland: 958±110, warmblood: 1489±126ms, pShetland: 606±39, warmblood: 589±38ms). In conclusion, although maternal RR interval is clearly higher in Shetland than in warmblood mares, fetal RR interval in the two breeds is on the same level. PMID:21907506

Nagel, Christina; Aurich, Jörg; Palm, Franziska; Aurich, Christine

2011-09-01

110

Serum AChE Activities Predict Exercise Heart Rate Parameters of Asymptomatic Individuals  

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Full Text Available Background specific heart rate parameters notably associate with variable risks of cardiovascular disease and mortal-ity, however, to date there are no readily available blood tests associated with these parameters. Because of the estab-lished parasympathetic contributions towards cardiac regulation, we challenged the working hypothesis that serum acetylcholinesterase (AChE activity is involved. Methods A total of 403 Healthy men and women were included in the study and underwent treadmill exercise testing. Prior to exercise testing the subject’s serum AChE activity levels were assessed by measuring rates of acetylthiocholine hydrolysis. Results In male subjects AChE activity was positively cor-related to resting heart rate (r = 0.210, p = 0.001. Complementing this observation, AChE activity was negatively correlated to the exercise-induced heart rate increase (r = –0.181, p = 0.005 and to heart rate recovery at 1, 2 and 5 minutes following cessation of exercise (r = –0.150, p = 0.022; r = –0.157, p = 0.016; r = –0.176, p = 0.008 respec-tively. This indicated that lower than average AChE activities, which presumably reflect increased peripheral ACh levels, might be correlated to favorable heart rate parameters. Similar observations were made in female subjects, ex-cept for lack of correlation to their resting heart rate. Additionally, we observed that we were able to stratify subjects into two groups of significantly different AChE activity (p = 0.001 based on a cut point of heart rate recovery below 20 beats one minute after cessation of exercise. Conclusion In asymptomatic individuals lower than average AChE activity is associated with favorable indices of exercise-inducible heart rate increase as well as heart rate recovery. Future studies will be needed to evaluate the added prognostic significance gained by implementing this marker into routine practice.

Canaani Jonathan

2010-12-01

111

Design and Development of a Heart Rate Measuring Device using Fingertip  

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In this paper, we presented the design and development of a new integrated device for measuring heart rate using fingertip to improve estimating the heart rate. As heart related diseases are increasing day by day, the need for an accurate and affordable heart rate measuring device or heart monitor is essential to ensure quality of health. However, most heart rate measuring tools and environments are expensive and do not follow ergonomics. Our proposed Heart Rate Measuring (H...

Hashem, M. M. A.; Shams, Rushdi; Kader, Md Abdul; Sayed, Md Abu

2013-01-01

112

Interrelation between donor and recipient heart rates during exercise after heterotopic cardiac transplantation.  

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The interrelation between the rates of the innervated recipient heart and the denervated donor heart at rest, on standing, and during the different phases of maximal exercise was studied in nine patients 1-6 months after heterotopic cardiac transplantation. The resting heart rate was significantly higher in the donor heart compared with the recipient heart. Eight of the nine recipient hearts and none of the donor hearts showed an increase in heart rate on standing up. All patients were exerci...

Yusuf, S.; Mitchell, A.; Yacoub, M. H.

1985-01-01

113

Method of Discriminant Gravity Tolerance using Heart Rate Variability  

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When returning on the earth by the space flight, the space deconditioning may be developed. As this countermeasure, the artificial gravity load device using the centrifuge is proposed in the space station. But the gravity load might cause the faint, and safe gravity load is uncertainty. We proposed that discriminate strength of gravity tolerance using heart rate variability time series. Step function was inputted to AR model estimated from heart rate variability time series during rest or under light gravity load, and strength of the gravity tolerance was discriminated by the step response function. On the result, discriminant accuracy was 87.5% by using heart rate variability time series when gravity load of 1.0 G was added to the human lying on the supine. Therefore, possibility of discriminant of gravity tolerance was obtained by using heart rate variability time series when sympathetic hyperactivity. Discriminant of the gravity tolerance is expected before countermeasure of space deconditioning is executed.

Yoshida, Yutaka; Yokoyama, Kiyoko; Takada, Hiroki; Iwase, Satoshi

114

Monofractality in RR Heart Rate by Multifractal Tools  

International Nuclear Information System (INIS)

Multifractal formalism is tested if it can work as a robust estimator of monofractals when scaling intervals are fixed. Intervals for scaling are selected to be consistent with known frequency bands of power spectral analysis used in estimates of heart rate variability: low frequency (LF), very low frequency (VLF), and ultra low frequency (ULF). Tests on fractional Brownian motions and a binomial cascade are performed to validate popular multifractal methods: Wavelet Transform Modulus Maxima and Multifractal Detrended Fluctuation Analysis. Then the methods are applied to identify monofractal elements of control processes driving the heart rate. A transition is found in the dynamic organization of autonomic nervous system control of the heart rate related to the change in scaling intervals. The control over the diurnal heart rate is of a multifractal type when considered in LF and of a monofractal type when observed in ULF. Additionally, this transition affects on a switch in a relation between widths of diurnal and nocturnal multifractal spectra. (author)

2009-05-01

115

Computer Sleep Stage Classification Using Heart Rate Data.  

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The paper explores the possibility of using discriminant analysis and Bayes classification procedures to determine sleep stage using only heart rate data. The recognition of sleep stages or even the ability to differentiate sleep from wakefulness using he...

A. J. Welch P. C. Richardson

1972-01-01

116

Recurrence Plots of Heart Rate Signals during Meditation  

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Full Text Available The current study analyses the dynamics of the heart rate signals during specific psychological states in order to obtain a detailed understanding of the heart rate patterns during meditation. In the proposed approach, heart rate time series available in Physionet database are used. The dynamics of the signals are then analyzed before and during meditation by examining the attractors in the phase space and recurrence quantification analysis. In general, the results reveal that the heart rate signals transit from a chaotic, highly-complex behavior before meditation to a low dimensional chaotic (and quasi-periodic motion during meditation. This can be due to decreased nonlinear interaction of variables in meditation states and may be related to increased parasympathetic activity and increase of relaxation state. The results suggest that nonlinear chaotic indices may serve as a quantitative measure for psychophysiological states.

Ateke Goshvarpour

2012-03-01

117

Heart Rate Response and Lactic Acid Concentration in Squash Players.  

Science.gov (United States)

It was concluded that playing squash is an activity that results in heart rate responses of sufficient intensity to elicit aerobic training effects without producing high lactic acid concentration in the blood. (MM)

Beaudin, Paula; And Others

1978-01-01

118

Peripheral oxygen saturation, heart rate, and blood pressure during dental treatment of children with cyanotic congenital heart disease  

Science.gov (United States)

OBJECTIVES: In this observational study, we evaluated the peripheral oxygen saturation (SpO2), heart rate, and blood pressure of children with cyanotic congenital heart disease who were undergoing dental extraction. METHODS: Forty-four patients between the ages of 6 and 12 years who underwent upper primary tooth extraction were included in the study. Of these, 20 patients were in the cyanotic congenital heart disease group and 24 were in the control group. RESULTS: Peripheral oxygen saturation, heart rate, and systolic blood pressure in the cyanotic congenital heart disease group varied quite significantly during the treatment protocol (p<0.05), with values of 80.5% (±7.6) to 82.8% (±7.8), 95.3 beats per minute (bpm) (±11.3) to 101.3 bpm (±9.8), and 93.6 mm Hg (±13,3) to 103.8 mm Hg (±12.7), respectively. The variations in the control group during the procedure were also significant. CONCLUSIONS: The changes observed during the study protocol, although statistically significant, were mild and lacked clinical relevance. The results indicate that dental treatment of children with cyanotic heart disease using a standardized protocol in decentralized offices without the support of a surgical center is safe.

Dutra, Rosane Menezes Faria; Neves, Itamara Lucia Itagiba; Neves, Ricardo Simoes; Atik, Edmar; de Paula Santos, Ubiratan

2014-01-01

119

A comparison of heart rate responses in racquet games.  

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The present study investigated the heart rate response to playing tennis with special reference to the skill levels and ages of the participants. Data obtained in a similar manner during earlier studies of badminton and squash players were compared with that obtained during tennis. The number of rallies, mean rally time and actual playing time in 30 minutes of play was also compared for the different skill levels and sports. Results showed that playing tennis raised the players' heart rates t...

Docherty, D.

1982-01-01

120

Heart rate turbulence and variability in patients with ventricular arrhythmias  

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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)...

2009-01-01

 
 
 
 
121

Heart rate variability in patients with chronic cerebral ischemia  

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The purpose of the work is to estimate the status of autonomic nervous system in patients with chronic cerebral ischemia by means of the analysis of heart rate variability at various stages of disease. 120 patients with chronic cerebral ischemia aged from 45 to 65 took part in the research. The comparison group included 30 patients with an arterial hypertension and without chronic cerebral ischemia. Heart rate variability analisis included time-domain and frequency-domain methods of five-minu...

2010-01-01

122

Heart rate turbulence and variability in patients with ventricular arrhythmias  

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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)...

2007-01-01

123

Heart rate variability and baroreflex sensitivity in idiopathic dilated cardiomyopathy  

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OBJECTIVE—To examine the relation between cardiac autonomic tone, assessed by baroreflex sensitivity and heart rate variability, and left ventricular function, arrhythmias on Holter monitoring, and clinical variables in patients with idiopathic dilated cardiomyopathy.?DESIGN—A prospective observational study.?PATIENTS—160 patients with idiopathic dilated cardiomyopathy and preserved sinus rhythm in the absence of antiarrhythmic drug treatment. Measures of heart rate variabil...

2000-01-01

124

Linear and Nonlinear Heart Rate Variability Indexes in Clinical Practice  

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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 ...

2012-01-01

125

Reduced heart rate variability following repair of tetralogy of Fallot  

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OBJECTIVE—To examine autonomic function as assessed by heart rate variability in patients 10 or more years after repair of tetralogy of Fallot, and to relate this to cardiac structure, function, and electrocardiographic indices.?METHODS—Heart rate variability was measured by standard time domain techniques on a 24 hour Holter ECG in 28 patients, aged 12 to 34 years (mean 19.5), who had undergone repair of tetralogy of Fallot at least 10 years previously. Echocardiography was p...

Mcleod, K.; Hillis, W.; Houston, A.; Wilson, N.; Trainer, A.; Neilson, J.; Doig, W.

1999-01-01

126

Heart Rate Variability Predicts ESRD and CKD-Related Hospitalization  

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Autonomic imbalance, a feature of both diabetes and hypertension, may contribute to adverse cardiovascular outcomes. In animal models, sympathetic nerve activity contributes to renal damage but the extent to which autonomic dysfunction precedes the development of CKD and ESRD in humans is unknown. We measured resting heart rate and heart rate variability in 13,241 adults (45- to 64-years old) followed for a median of 16 years in the Atherosclerosis Risk in Communities (ARIC) Study. We examine...

Brotman, Daniel J.; Bash, Lori D.; Qayyum, Rehan; Crews, Deidra; Whitsel, Eric A.; Astor, Brad C.; Coresh, Josef

2010-01-01

127

Heart rate and estimated energy expenditure during ballroom dancing.  

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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 interact...

Blanksby, B. A.; Reidy, P. W.

1988-01-01

128

Automatic recording of fish heart rate on a personal computer  

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From acoustic tags operated into fish in a closed system, the heartbeat signals are sent via underwater telemetry and counted on a personal computer. The computer removes false pulses caused by noise, and calculates the heart rate for one minute based on reliable heartbeats. Up to 6 fish can be monitored in a sequence of one minute per fish. The heart rate is stored on a file, or transferred to another computer.

Floen, Svein; Totland, Bjørn; Øvredal, Jan Tore

1988-01-01

129

Heart rate variability in natural time and 1/f "noise"  

Science.gov (United States)

Several studies have shown that heart rate fluctuations exhibit the ubiquitous 1/f behavior which is altered in desease. Furthermore, the analysis of electrocardiograms in natural time reveals that important malfunctions in the complex system of the human heart can be identified. Here, we present a simple evolution model in natural time that exhibits the 1/fa behavior with a close to unity. The results of this model are consistent with a progressive modification of heart rate variability in healthy children and adolescents. The model results in complexity measures that separate healthy dynamics from patients as well as from sudden cardiac death individuals.

Sarlis, N. V.; Skordas, E. S.; Varotsos, P. A.

2009-07-01

130

Heart rate variability predicts ESRD and CKD-related hospitalization.  

Science.gov (United States)

Autonomic imbalance, a feature of both diabetes and hypertension, may contribute to adverse cardiovascular outcomes. In animal models, sympathetic nerve activity contributes to renal damage but the extent to which autonomic dysfunction precedes the development of CKD and ESRD in humans is unknown. We measured resting heart rate and heart rate variability in 13,241 adults (45- to 64-years old) followed for a median of 16 years in the Atherosclerosis Risk in Communities (ARIC) Study. We examined heart rate parameters by quartiles, defining those in the lowest quartile (by time and frequency domain measures separately) as the risk group of interest. We identified 199 cases of incident ESRD and 541 patients with CKD-related hospitalizations; higher resting heart rate and lower heart rate variability associated with both outcomes. The fully adjusted hazard ratios for ESRD were 1.98 (95% confidence interval [CI] 1.45 to 2.70) among those in the highest heart rate quartile and 1.56 (95% CI 1.14 to 2.14) for high-frequency power. Other time and frequency domain measures were similarly and significantly associated with ESRD and CKD-related hospitalizations. These results suggest that autonomic dysfunction may be an important risk factor for ESRD and CKD-related hospitalizations and call for further studies to define the mechanisms that underlie these associations. PMID:20616169

Brotman, Daniel J; Bash, Lori D; Qayyum, Rehan; Crews, Deidra; Whitsel, Eric A; Astor, Brad C; Coresh, Josef

2010-09-01

131

Age related reference ranges for respiration rate and heart rate from 4 to 16 years  

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Background: Clinical vital signs in children (temperature, heart rate, respiration rate, and blood pressure) are an integral part of clinical assessment of degree of illness or normality. Despite this, only blood pressure and temperature have a reliable evidence base. The accepted ranges of heart and respiration rate vary widely.

Wallis, L.; Healy, M.; Undy, M.; Maconochie, I.

2005-01-01

132

Effect of Aerobic Training on Heart Rate Recovery in Patients with Established Heart Disease; a Systematic Review  

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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 study the relationship between aerobic training and Heart Rate Recovery (HRR) in patients with established heart disease. Methods (Quasi) randomized clinical trials on aerobic exercise training in adults with established heart disease were identified through electronic database and reference screening. Two reviewers extracted data and assessed the risk of bias and therapeutic validity. Methodological validity was evaluated using an adapted version of the Cochrane Collaboration’s tool for assessing risk of bias and the therapeutic validity of the interventions was assessed with a nine-itemed, expert-based rating scale (CONTENT). Scores range from 0 to 9 (score ? 6 reflecting therapeutic validity). Results Of the 384 articles retrieved, 8 studies (449 patients) were included. Three of the included studies demonstrated adequate therapeutic validity and five demonstrated low risk of bias. Two studies showed both adequate therapeutic validity and a low risk of bias. For cardiac patients aerobic exercise training was associated with more improvement in HRR compared to usual care. Conclusion The present systematic review shows a level 1A evidence that aerobic training increases HRR in patients with established heart disease.

Snoek, Johan A.; van Berkel, Sietske; van Meeteren, Nico; Backx, Frank J. G.; Daanen, Hein A. M.

2013-01-01

133

Cuff inflation during ambulatory blood pressure monitoring and heart rate  

Directory of Open Access Journals (Sweden)

Full Text Available Mia Skov-Madsen, My Svensson, Jeppe Hagstrup ChristensenDepartment of Nephrology, Aarhus University Hospital, Aalborg, DenmarkIntroduction: Twenty four-hour ambulatory blood pressure monitoring is a clinically validated procedure in evaluation of blood pressure (BP. We hypothesised that the discomfort during cuff inflation would increase the heart rate (HR measured with 24-h ambulatory BP monitoring compared to a following HR measurement with a 24-h Holter monitor.Methods: The study population (n = 56 were recruited from the outpatient’s clinic at the Department of Nephrology, Aalborg Hospital, Aarhus University Hospital at Aalborg, Denmark. All the patients had chronic kidney disease (CKD. We compared HR measured with a 24-h Holter monitor with a following HR measured by a 24-h ambulatory BP monitoring.Results: We found a highly significant correlation between the HR measured with the Holter monitor and HR measured with 24-h ambulatory blood pressure monitoring (r = 0.77, p < 0.001. Using the Bland-Altman plot, the mean difference in HR was only 0.5 beat/min during 24 hours with acceptable limits of agreement for both high and low HR levels. Dividing the patients into groups according to betablocker treatment, body mass index, age, sex, angiotensin-converting enzyme inhibitor treatment, statins treatment, diuretic treatment, or calcium channel blocker treatment revealed similar results as described above.Conclusion: The results indicate that the discomfort induced by cuff inflation during 24-h ambulatory BP monitoring does not increase HR. Thus, 24-h ambulatory BP monitoring may be a reliable measurement of the BP among people with CKD.Keywords: ambulatory blood pressure monitoring, Holter monitoring, heart rate, chronic kidney disease, hypertension

Mia Skov-Madsen

2008-11-01

134

Heart rate recovery in patients with hypertrophic cardiomyopathy.  

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Recovery in heart rate (HR) after exercise is a measure of autonomic function and a prognostic indicator in cardiovascular disease. The aim of this study was to characterize heart rate recovery (HRR) and to determine its relation to cardiac function and morphology in patients with hypertrophic cardiomyopathy (HC). We studied 18 healthy volunteers and 41 individuals with HC. All patients underwent clinical assessment and transthoracic echocardiography. Continuous beat-by-beat assessment of HR was obtained during and after cardiopulmonary exercise testing using finger plethysmography. HRR and power spectral densities were calculated on 3 minutes of continuous RR recordings. Absolute HRR was lower in patients than that in controls at 1, 2, and 3 minutes (25.7 ± 8.4 vs 35.3 ± 11.0 beats/min, p <0.001; 36.8 ± 9.4 vs 53.6 ± 13.2 beats/min, p <0.001; 41.2 ± 12.2 vs 62.1 ± 14.5 beats/min, p <0.001, respectively). HRR remained lower in patients at 2 and 3 minutes after normalization to peak HR. After normalization to the difference in HR between peak exercise and rest, HRR was significantly impaired in individuals with obstructive HC at 3 minutes compared with controls. HR at 3 minutes correlated with peak left ventricular outflow tract gradient (B 0.154 beats/min/mm Hg, confidence interval 0.010 to 0.299, p = 0.037) and remained a significant predictor of HRR after multivariable analysis. Spectral analysis showed a trend toward an increased low-frequency to high-frequency ratio in patients (p = 0.08) suggesting sympathetic predominance. In conclusion, HRR is impaired in HC and correlates with the severity of left ventricular outflow tract gradient. Prospective studies of the prognostic implications of impaired HRR in HC are warranted. PMID:24461767

Patel, Vimal; Critoph, Christopher H; Finlay, Malcolm C; Mist, Bryan; Lambiase, Pier D; Elliott, Perry M

2014-03-15

135

Heart rate variability and heat sensation during CT coronary angiography: Low-osmolar versus iso-osmolar contrast media  

International Nuclear Information System (INIS)

Background: During computed tomography coronary angiography (CTCA) unexpected changes in heart rate while scanning may affect image quality. Purpose: To evaluate whether an iso-osmolar contrast medium (IOCM, iodixanol) and a low-osmolar contrast medium (LOCM, iomeprol) affect heart rate and experienced heat sensation differently. Material and Methods: One hundred patients scheduled for CTCA were randomized to receive either iodixanol 320 mgI/ml or iomeprol 400 mgI/ml. Depending on their heart rate, the patients were assigned to one of five scanning protocols, each optimized for different heart rate ranges. During scanning the time between each heart beat (hb) was recorded, and the corresponding heart rate was calculated. For each contrast medium (CM) the average heart rate, the variation in heart rate from individual mean heart rate, and the mean deviation from the predefined scanning protocol were calculated. Experience of heat was obtained immediately after scanning by using a visual analog scale (VAS). Examination quality was rated by two radiologists on a three-point scale. Results: The mean variation in heart rate after IOCM was 1.4 hb/min and after LOCM it was 4.4 hb/min (NS). The mean deviations in heart rate from that in the predefined scanning protocol were 2.0 hb/min and 4.7 hb/min, respectively (NS). A greater number of arrhythmic hb were observed after LOCM compared with IOCM (P<0.001). There was no statistically significant difference in image quality. The LOCM group reported a stronger heat sensation after CM injection than the IOCM group (VAS =36 mm and 18 mm, P<0.05). Conclusion: At clinically used concentrations the IOCM, iodixanol 320 mgI/ml, does not increase the heart rate during CTCA and causes less heart arrhythmia and less heat sensation than the LOCM, iomeprol 400 mgI/ml

2010-09-01

136

Blood pressure and heart rate in young thalassemia major patients.  

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The analysis of blood pressure (BP) and heart rate (HR) variability is currently used to investigate the mechanisms responsible for cardiovascular control; therefore, we assessed whether an impairment of 24-h BP and HR profiles and sympathovagal interaction modulating cardiovascular function was present in patients with thalassemia major (TM) in preclinical phase of heart disease. Nine beta-thalassemic patients 18 years old without clinical signs of cardiac failure and 9 age- and sex-matched ...

1998-01-01

137

Estimating Energy Expenditure from Heart Rate in Older Adults: A Case for Calibration  

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Background Accurate measurement of free-living energy expenditure is vital to understanding changes in energy metabolism with aging. The efficacy of heart rate as a surrogate for energy expenditure is rooted in the assumption of a linear function between heart rate and energy expenditure, but its validity and reliability in older adults remains unclear. Objective To assess the validity and reliability of the linear function between heart rate and energy expenditure in older adults using different levels of calibration. Design Heart rate and energy expenditure were assessed across five levels of exertion in 290 adults participating in the Baltimore Longitudinal Study of Aging. Correlation and random effects regression analyses assessed the linearity of the relationship between heart rate and energy expenditure and cross-validation models assessed predictive performance. Results Heart rate and energy expenditure were highly correlated (r?=?0.98) and linear regardless of age or sex. Intra-person variability was low but inter-person variability was high, with substantial heterogeneity of the random intercept (s.d.?=?0.372) despite similar slopes. Cross-validation models indicated individual calibration data substantially improves accuracy predictions of energy expenditure from heart rate, reducing the potential for considerable measurement bias. Although using five calibration measures provided the greatest reduction in the standard deviation of prediction errors (1.08 kcals/min), substantial improvement was also noted with two (0.75 kcals/min). Conclusion These findings indicate standard regression equations may be used to make population-level inferences when estimating energy expenditure from heart rate in older adults but caution should be exercised when making inferences at the individual level without proper calibration.

Schrack, Jennifer A.; Zipunnikov, Vadim; Goldsmith, Jeff; Bandeen-Roche, Karen; Crainiceanu, Ciprian M.; Ferrucci, Luigi

2014-01-01

138

A comparison of heart rate responses in racquet games.  

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The present study investigated the heart rate response to playing tennis with special reference to the skill levels and ages of the participants. Data obtained in a similar manner during earlier studies of badminton and squash players were compared with that obtained during tennis. The number of rallies, mean rally time and actual playing time in 30 minutes of play was also compared for the different skill levels and sports. Results showed that playing tennis raised the players' heart rates to 68-70% of their predicted maximum heart rate (PMHR). Playing squash and badminton could raise heart rates to 80-85% of the players' PMHR which was significantly higher than the values obtained for tennis. The actual skill level of the participants within their chosen sport did not have a significant effect in predicting the physical demands of squash or tennis but was important in predicting the heart rate response of badminton players. The more skillful the badminton player the greater the cardiac response as a result of game play. Analysis of time spent in actual play revealed that tennis players were involved in play for only five of the thirty minutes of game play, compared to 15 and 10 min respectively for squash and badminton. Skill level within each sport was only a significant factor in predicting length of play for squash players in which the medium and highly skilled groups played significantly longer than those of a lower level of skill. PMID:7104564

Docherty, D

1982-06-01

139

AUTONOMIC CONTROL OF HEART RATE AFTER EXERCISE IN TRAINED WRESTLERS  

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The objective of this study was to establish differences in vagal reactivation, through heart rate recovery and heart rate variability post exercise, in Brazilian jiu-jitsu wrestlers (BJJW). A total of 18 male athletes were evaluated, ten highly trained (HT) and eight moderately trained (MT), who performed a maximum incremental test. At the end of the exercise, the R-R intervals were recorded during the first minute of recovery. We calculated heart rate recovery (HRR60s), and performed linear and non-linear (standard deviation of instantaneous beat-to-beat R-R interval variability – SD1) analysis of heart rate variability (HRV), using the tachogram of the first minute of recovery divided into four segments of 15 s each (0-15 s, 15-30 s, 30-45 s, 45-60 s). Between HT and MT individuals, there were statistically significant differences in HRR60s (p <0.05) and in the non linear analysis of HRV from SD130-45s (p <0.05) and SD145-60s (p <0.05). The results of this research suggest that heart rate kinetics during the first minute after exercise are related to training level and can be used as an index for autonomic cardiovascular control in BJJW.

Baez, San Martin E.; Von Oetinger, A.; Canas, Jamett R.; Ramirez, Campillo R.

2013-01-01

140

AUTONOMIC CONTROL OF HEART RATE AFTER EXERCISE IN TRAINED WRESTLERS  

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Full Text Available The objective of this study was to establish differences in vagal reactivation, through heart rate recovery and heart rate variability post exercise, in Brazilian jiu-jitsu wrestlers (BJJW. A total of 18 male athletes were evaluated, ten highly trained (HT and eight moderately trained (MT, who performed a maximum incremental test. At the end of the exercise, the R-R intervals were recorded during the first minute of recovery. We calculated heart rate recovery (HRR60s, and performed linear and non-linear (standard deviation of instantaneous beat-to-beat R-R interval variability – SD1 analysis of heart rate variability (HRV, using the tachogram of the first minute of recovery divided into four segments of 15 s each (0-15 s, 15-30 s, 30-45 s, 45-60 s. Between HT and MT individuals, there were statistically significant differences in HRR60s (p <0.05 and in the non linear analysis of HRV from SD130-45s (p <0.05 and SD145-60s (p <0.05. The results of this research suggest that heart rate kinetics during the first minute after exercise are related to training level and can be used as an index for autonomic cardiovascular control in BJJW.

Carlos F Henríquez

2013-04-01

 
 
 
 
141

Autonomic control of heart rate after exercise in trained wrestlers.  

Science.gov (United States)

The objective of this study was to establish differences in vagal reactivation, through heart rate recovery and heart rate variability post exercise, in Brazilian jiu-jitsu wrestlers (BJJW). A total of 18 male athletes were evaluated, ten highly trained (HT) and eight moderately trained (MT), who performed a maximum incremental test. At the end of the exercise, the R-R intervals were recorded during the first minute of recovery. We calculated heart rate recovery (HRR60s), and performed linear and non-linear (standard deviation of instantaneous beat-to-beat R-R interval variability - SD1) analysis of heart rate variability (HRV), using the tachogram of the first minute of recovery divided into four segments of 15 s each (0-15 s, 15-30 s, 30-45 s, 45-60 s). Between HT and MT individuals, there were statistically significant differences in HRR60s (p <0.05) and in the non linear analysis of HRV from SD130-45s (p <0.05) and SD145-60s (p <0.05). The results of this research suggest that heart rate kinetics during the first minute after exercise are related to training level and can be used as an index for autonomic cardiovascular control in BJJW. PMID:24744476

Henríquez, Olguín C; Báez, San Martín E; Von Oetinger, A; Cañas, Jamett R; Ramírez, Campillo R

2013-06-01

142

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

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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.

Ali Metin Esen

2010-04-01

143

Heart rate recovery in exercise test in diabetic patients with and without microalbuminuria  

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BACKGROUND Diabetes mellitus (DM) has a lot of complications such as macrovessel and microvessel disease. Another complication of DM is cardiac autonomic neuropathy (CAN), which have effect on automatic nervous system of heart. Failure in heart rate slowing after exercise is a presentation of this abnormality. METHODS We selected diabetic patients and divided them to case and control group based on microalbuminuria. Case group comprised of diabetic patients with microalbuminuria and control group included those without microalbuminuria. Patients in both groups exercised on treadmill using Bruce protocol and heart rate was measured in first and second minutes in the recovery period. RESULTS We selected 35 patients with microalbuminuria (case group) and 35 without microalbuminuria (control group) among diabetic patients. No statistically significant difference was seen in sex and age between case and control groups. Heart rate recovery in the first minute of recovery in the case and control groups did not show significant difference; but in the second minute of recovery, it was significantly higher in control group (97 ± 19.4 vs. 101.9 ± 12.4 beat per minute, P = 0.04). CONCLUSION In this study we evaluated the heart rate recovery or deceleration in diabetic patients with albuminuria and without microalbuminuria in recovery phase after exercise test. We found out that heart rate recovery at the second minute in the case and control groups has statistically significant difference but at the first minute, it did not.

Pourmoghaddas, Ali; Moghaddasian, Adrineh; Garakyaraghi, Mohammad; Nezarat, Negin; Mehrabi, Ali

2013-01-01

144

Heart rate variability and target organ damage in hypertensive patients  

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Full Text Available Abstract Background We evaluated the association between linear standard Heart Rate Variability (HRV measures and vascular, renal and cardiac target organ damage (TOD. Methods A retrospective analysis was performed including 200 patients registered in the Regione Campania network (aged 62.4?±?12, male 64%. HRV analysis was performed by 24-h holter ECG. Renal damage was assessed by estimated glomerular filtration rate (eGFR, vascular damage by carotid intima-media thickness (IMT, and cardiac damage by left ventricular mass index. Results Significantly lower values of the ratio of low to high frequency power (LF/HF were found in the patients with moderate or severe eGFR (p-value? Conclusions Depressed HRV appeared to be associated with vascular and renal TOD, suggesting the involvement of autonomic imbalance in the TOD. However, as the mechanisms by which abnormal autonomic balance may lead to TOD, and, particularly, to renal organ damage are not clearly known, further prospective studies with longitudinal design are needed to determine the association between HRV and the development of TOD.

Melillo Paolo

2012-11-01

145

Effect of furosemide and torasemide on heart rate variability and ventricular rhythm disorders in patients with chronic heart failure complicating ischemic heart disease: comparative nonrandomized study  

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Full Text Available Aim. To study effect of diuretic therapy with furosemide and torasemide on heart rate variability (HRV and frequency of ventriclar rhythm disorders in patients with chronic heart failure (CHF complicating ischemic heart disease (IHD.Material and methods. Patients (n=107 with CHF III-IV functional class (NYHA complicating IHD were examined. The first group of patients received furosemide, 20-60 mg QD (n=52, the second group received torasemide, 5-20 mg QD (n=55. Analysis of heart rhythm disorders and the basic HRV indicators was performed by ECG 10-minute recordings initially and after 10 days of therapy.Results. Decrease in time and spectral HRV parameters and increase in daily number of ventricular extrasystoles was found in furosemide treated patients. Improvement of HRV parameters and reduction of daily number of ventricular rhythm disorders was found torasemide treated patients.Conclusion. Torasemide therapy improves an autonomic regulation of heart rhythm and leads to the reduction of ventricular heart rhythm disorders in patients with CHF complicating IHD.

H.H. Shugushev

2010-01-01

146

Discrimination power of long-term heart rate variability measures for Chronic Heart Failure detection  

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The aim of this study was to investigate the discrimination power of standard long-term Heart Rate Variability (HRV) measures for the diagnosis of Chronic Heart Failure (CHF). We performed a retrospective analysis on 4 public Holter databases, analyzing the data of 72 normal subjects and 44 patients suffering from CHF. To assess the discrimination power of HRV measures, we adopted an exhaustive search of all possible combinations of HRV measures and we developed classifiers based on Classi...

Melillo, Paolo; Fusco, Roberta; Sansone, Mario; Bracale, Marcello; Pecchia, Leandro

2011-01-01

147

Heart dimensions may influence the occurrence of the heart rate deflection point in highly trained cyclists  

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OBJECTIVES: To determine whether the heart rate (HR) response to exercise in 21 highly trained cyclists (mean (SD) age 25 (3) years) was related to their heart dimensions. METHODS: Before performing an incremental exercise test involving a ramp protocol with workload increases of 25 W/min, each subject underwent echocardiographic evaluation of the following variables: left ventricular end diastolic internal diameter (LVIDd), left ventricular posterior wall thickness at end diastole (LVP...

Lucia, A.; Carvajal, A.; Boraita, A.; Serratosa, L.; Hoyos, J.; Chicharro, J. L.

1999-01-01

148

Chaotic Signatures of Heart Rate Variability and Its Power Spectrum in Health, Aging and Heart Failure  

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A paradox regarding the classic power spectral analysis of heart rate variability (HRV) is whether the characteristic high- (HF) and low-frequency (LF) spectral peaks represent stochastic or chaotic phenomena. Resolution of this ftitration undamental issue is key to unraveling the mechanisms of HRV, which is critical to its proper use as a noninvasive marker for cardiac mortality risk assessment and stratification in congestive heart failure (CHF) and other cardiac dysfunctions. However, co...

Wu, Guo-qiang; Arzeno, Natalia M.; Shen, Lin-lin; Tang, Da-kan; Zheng, Da-an; Zhao, Nai-qing; Eckberg, Dwain L.; Poon, Chi-sang

2009-01-01

149

Analysis of Heart Rate Variability Using Time-Varying Filtering of Heart Transplanted Patients  

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In this paper, we analyze the heart rate variability (HRV), obtained by using the time-varying integral pulse frequency modulation (TVIPFM) which is well adapted to the exercise stress testing. We consider that the mean heart period is varying function of time, during exercise. This technique allows the estimation of the autonomic nervous system modulation (ANS) from the beat occurrences. The estimated respiratory sinus arrhythmia is then filtered in the time-frequency domain around the respi...

Laouini, Ghailen; Meste, Olivier; Meo, Marianna

2012-01-01

150

Kramers-Moyal Expansion of Heart Rate Variability  

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The first six Kramers-Moyal coefficients were extracted from human heart rate variability recordings. The method requires the determination of the Markov time and of the proper conditional probability densities. We analyzed heart rate data recorded in a group of ten young, healthy subjects. We obtained non-negligible higher order Kramers-Moyal (K-M) terms in 6 h nighttime parts of the 24 h recordings. This indicates that the data is a non-Gaussian process and probably a correlated signal. The analysis yielded important new insights into the character and distribution of the stochastic processes measured in healthy group. In the night hours, the dominant oscillation in the heart rate is the so called respiratory sinus arrhythmia (RSA) -- a physiological phenomenon in which respiration acts as a drive for the heart rate. Certain kinds of pathology may disrupt RSA. We compared nighttime recordings of the healthy group with those recorded in six patients with hypertrophic cardiomyopathy (HCM). HCM is generally a pathology of heart cells but abnormalities in autonomic regulation are also observed. Using the higher order Kramers-Moyal coefficients, we analyzed the skewness and kurtosis in the nighttime recordings for the normal subjects.

Petelczyc, M.; ?ebrowski, J. J.; Baranowski, R.

2009-05-01

151

Heart rate, alveolar gases and blood lactate during synchronized swimming.  

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Heart rate, alveolar gas partial pressures and blood lactate (BLa) concentration were measured during synchronized swimming in six subjects. During upside-down breath-holding lasting 50 s, heart rate fell progressively from 98 +/- 14 to 70 +/- 7 beats min-1 (mean +/- S.D.). While breath-holding during the compulsory figures, the subjects' heart rate increased to 142 +/- 5 beats min-1 and then fell to 72 +/- 10 beats min-1. At the end of breath-holding, alveolar oxygen pressure had fallen significantly (60 mmHg), whereas alveolar carbon dioxide pressure showed only minor changes (48 mmHg). The increase in BLa concentration due to the execution of compulsory figures was approximately 1 mM; in the free routines, BLa concentration increased by 3.4 +/- 0.5 mM. The net energy cost of completing a compulsory figures lasting 45 s was 34.6 kJ. PMID:8497011

Figura, F; Cama, G; Guidetti, L

1993-04-01

152

Estimating sleep disordered breathing based on heart rate analysis.  

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Heart rate variability and the analysis of the ECG with ECG derived respiration has been used to diagnose sleep disordered breathing. Recently it was possible to distinguish obstructive sleep apnea and central sleep apnea. This can be achieved by analyzing both, heart rate variability and the more mechanically induced ECG derived respiration in parallel. In addition the analysis of cardiopulmonary coupling facilitates to predict the personal risk factor for cardiovascular disorders. The analysis of heart rate, ECG and respiration goes beyond this analysis. Some studies indicate that it is possible to derive sleep stages from these signals. In order to derive sleep stages a more complex analysis of the signals is applied taking into account non-linear properties by using methods of statistical physics. To extract coupling information supports the distinction between sleep stages. Results are reported in this review. PMID:24111248

Penzel, Thomas; Glos, Martin; Schobel, Christoph; Lal, Sara; Fietze, Ingo

2013-01-01

153

Impaired heart rate recovery in patients with endemic fluorosis.  

Science.gov (United States)

The objective of the present study was to determine the heart rate recovery index (HRRI), a marker of autonomic nervous system function in patients with endemic fluorosis. Forty patients with endemic fluorosis (16 men/24 women) and 40 age-, sex-, and body mass index-matched healthy controls (16 men/24 women) with normal fluoride intake were enrolled in this study. HRRI was calculated by subtracting the heart rate values at the first, second, and third minutes of the recovery phase from the peak heart rate (HRRI 1, HRRI 2, HRRI 3). Urine fluoride levels of fluorosis patients were significantly (P?

Adali, M Koray; Varol, Ercan; Aksoy, Fatih; Icli, Atilla; Ersoy, I Hakki; Ozaydin, Mehmet; Erdogan, Dogan; Dogan, Abdullah

2013-06-01

154

Effect of ivabradine-induced heart rate reduction on flow-mediated dilation measured with high-sensitivity ultrasound in patients with stable coronary heart disease  

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Background Experimental data suggests that exclusive heart rate reduction with ivabradine is associated with the amelioration of the endothelial function. Since it is presently unknown whether this also applies to humans, the aim of this pilot study was to investigate whether heart rate reduction with ivabradine modulates the endothelial function in humans with an established coronary heart disease. Methods Using high-sensitivity ultrasound, we analysed the flow-mediated (FMD) and nitro-mediated dilation (NMD) of the brachial artery in 25 patients (62.9?±?8.4 years) with a stable coronary heart disease and a resting heart rate of ?70 beats per minute (bpm). To assess acute effects, measurements were performed before and 4 hours after the first intake of ivabradine 7.5 mg. Sustained effects of an ivabradine therapy (5 mg to 7.5 mg twice daily) were investigated after 4 weeks. Results We found a significant decrease in heart rate, both 4 hours after the intake of 7.5 mg of ivabradine (median -8 [interquartile range (IQR) -14 to -4] bpm) and after 4 weeks of twice daily intake (median -10 [IQR-17 to -5] bpm) (p?FMD did not change significantly: neither after first dose of ivabradine nor after sustained therapy (baseline FMD: median 5.0 [IQR 2.4 to 7.9]%; FMD 4 hours after 7.5 mg of ivabradine: median 4.9 [IQR 2.7 to 9.8]%; FMD after 4 weeks of ivabradine therapy: median 6.1 [IQR 4.3 to 8.2]%). No significant changes of the NMD were observed. In regression analysis, the heart rate and FMD did not correlated, irrespective of the ivabradine intake (r2?=?0.086). Conclusion In conclusion, in our study heart rate reduction through ivabradine does not improve the endothelial function in patients with a stable coronary heart disease. Moreover, we found no correlation between the heart rate and the endothelial function.

2014-01-01

155

Evaluation of the heart rate and arrhythmias following the Maze procedure for chronic atrial fibrillation  

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Full Text Available PURPOSE: To assess the presence and the prevalence of arrhythmias and the variability of the heart rate in the medium-term postoperative period following the maze procedure for chronic atrial fibrillation (AF. METHODS: Seventeen patients with a mean age of 51.7±12.9 years, who previously underwent the maze procedure without cryoablation for chronic atrial fibrillation, were evaluated with the 24 hour electrocardiogram (ECG - Holter monitoring from the 6th month after the operation. Valvular and coronary procedures were concomitantly performed. RESULTS: The mean heart rate during Holter monitoring was 82±8bpm; the maximal heart rate was 126 ± 23bpm and the minimal heart rate 57±7bpm. Sinus rhythm was found in 10 (59% patients and atrial rhythm was found in 7 (41%. Supraventricular extrasystoles had a rate of 2.3±5.5% of the total number of heartbeats and occurred in 16 (94% patients. Six (35% patients showed nonsustained atrial tachycardia. Ventricular extrasystoles, with a rate of 0.8±0.5% of the total heartbeats, occurred in 14 (82% patients. The chronotropic competence was normal in 9 (53% patients and attenuated in 8 (47%. The atrioventricular conduction (AV was unchanged in 13 (76% patients and there were 4 (24% cases of first degree atrioventricular block (AVB. CONCLUSION: After the maze procedure, the values for the mean heart rate, AV conduction and chronotropic competence approach the normal range, although some cases show attenuation of the chronotropic response, first degree AV block or benign arrhythmias.

Cunha Bartira

1999-01-01

156

Music structure determines heart rate variability of singers  

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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 be...

2013-01-01

157

Thermoregulation mediated by conditioned heart-rate changes in pigeons  

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Pigeons were subjected to an apparent heat (44 °C) or cold (30 °C) load by means of a thermode located next to their thermosensitive spinal cord. They were then able to obtain brief thermonormality (40 °C) spells if they changed their heart-rate by a preset amount above (or below) their baseline heartrate. In the final experiments the animals increased (or decreased) their heart-rate by about 25% within 12 training sessions, thereby achieving a partial thermoregulation: they were able to m...

Delius, Juan; Sieland, Markus; Rautenberg, Werner; May, Ba?rbel

1981-01-01

158

Phase plane based identification of fetal heart rate patterns  

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Using a phase plane analysis (PPA) of the spatial spread of trajectories of the fetal heart rate and its time-derivative we characterize the fetal heart rate patterns (fHRP) as defined by Nijhuis. For this purpose, we collect 22 fetal magnetocardiogram using a 151 SQUID system from 22 low-risk fetuses in gestational ages ranging from 30 to 37 weeks. Each study lasted for 30 minutes. After the attenuation of the maternal cardiac signals, we identify the R waves using an adaptive Hilbert transf...

Govindan, Rathinaswamy B.; Vairavan, Srinivasan; Sriram, Bhargavi; Wilson, James D.; Preissl, Hubert; Eswaran, Hari

2011-01-01

159

Pathophysiology of exercise heart rate recovery: a comprehensive analysis.  

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Expanded use of exercise heart rate recovery (HRR) has renewed interest in the pathophysiology of heart rate control. This study uses basic physiologic principles to construct a unique model capable of describing the full time course of sympathetic and parasympathetic activity during HRR. The model is tested in a new study of 22 diverse subjects undergoing both maximal and submaximal treadmill exercise. Based on this analysis, prolongation of HRR involves changes within the sinus node, changes in sympathetic function, in parasympathetic function, and in the central mechanisms regulating autonomic balance. The methods may provide unique insight into alterations in autonomic control in health and disease. PMID:23530480

Pierpont, Gordon L; Adabag, Selcuk; Yannopoulos, Demetri

2013-03-01

160

Association of Metabolic Syndrome With Exercise Capacity and Heart Rate Recovery in Patients With Coronary Heart Disease in the Heart and Soul Study  

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It is not known whether the metabolic syndrome is associated with poor exercise capacity among patients who have established coronary heart disease. We evaluated the association of the metabolic syndrome with treadmill exercise capacity and heart rate recovery among patients who had coronary heart disease. We measured treadmill exercise capacity (METs) and heart rate recovery (beats per minute) in 943 subjects who had known coronary heart disease. Of these, 377 (40%) had the metabolic syndrom...

Spies, Christian; Otte, Christian; Kanaya, Alka; Pipkin, Sharon S.; Schiller, Nelson B.; Whooley, Mary A.

2005-01-01

 
 
 
 
161

Migration and torsions of the conotruncus in the chick embryo heart: observational evidence and conclusions drawn from experimental intervention.  

Science.gov (United States)

It seems difficult to escape the conclusion that conotruncal migration and torsions do occur: The amplitude, direction and timing of these movements can be accurately tracked and they can be experimentally arrested. The movements have a significant function: Associated with the partitionings, they regulate the outlet ventricular distribution at two levels, permitting an adjustment between the ampullae and conus (a function of migration) and between the proximal and distal conal segments (via torsions). Their defects result in malalignments--double outlet right ventricle and transposition of the great vessels, respectively. The mechanism of the migration is linked to the differential growth of ampullae; the right ampulla and certain areas of this ampulla appear as dominant during the embryonic period. The conus is carried by the right ampulla and passively undergoes migration. The mechanism of the torsions is not entirely clear. The proximal torsion appears to be linked to a myocardium--jelly dissociation; the distal torsion seems to be linked to an oriented myocardial growth of its wall; the torsion of the truncus is evidently passive, occurring as a consequence of the conus distal torsion. PMID:3831028

Dor, X; Corone, P

1985-11-01

162

Impact of Sleep-Disordered Breathing on Heart Rate Turbulence in Heart Failure Patients  

Science.gov (United States)

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.

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

163

An exploration of heart rate response to differing music rhythm and tempos.  

Science.gov (United States)

The aim of this study was to investigate acute cardiac response and heart rate variability (HRV) when listening to differing forms of music. Eleven healthy men aged between 18 and 25 years old were included in the study. HRV was recorded at rest for ten minutes with no music, then were asked to listen to classical baroque or heavy metal music for a period of 20 min. It was noted that heart rate variability did not affect HRV indices for time and frequency. In conclusion, music with different tempos does not influence cardiac autonomic regulation in men. However more studies are suggested to explore this topic in greater detail. PMID:24767959

da Silva, Ariany G; Guida, Heraldo L; Antônio, Ana Márcia Dos S; Marcomini, Renata S; Fontes, Anne M G G; Carlos de Abreu, Luiz; Roque, Adriano L; Silva, Sidney B; Raimundo, Rodrigo D; Ferreira, Celso; Valenti, Vitor E

2014-05-01

164

Effects of Moxa (Artemisia Vulgaris Smoke Inhalation on Heart Rate and Its Variability  

Directory of Open Access Journals (Sweden)

Full Text Available Objective: To evaluate the changes of human heart rate (HR and heart rate variability (HRV during and after moxa smoke inhalation and to investigate the effects of moxa smoke on human autonomic nervous system. Methods: 24 healthy volunteers were exposed to moxa smoke with their HRV parameters measured before, during and after the moxa smoke inhalation. Results: The healthy volunteers exposed to moxa smoke had significant reductions in HR and also significant changes in HRV parameters. Conclusions: Moxa smoke can improve the autonomic nervous system activity. The inhalation of moxa smoke will induce a depressant effect on human body.

Ping Liu

2011-06-01

165

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

Science.gov (United States)

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.

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

2013-01-01

166

Interchangeability between heart rate and photoplethysmography variabilities during sympathetic stimulations  

International Nuclear Information System (INIS)

Photoplethysmography variability (PPGV) is currently considered to be a good surrogate to heart rate variability (HRV) measurements using the time between two pulse waves instead of RR intervals. Nevertheless, the interchangeability between HRV and PPGV has never been evaluated in situations with severe alterations in the autonomic nervous system (ANS). We aimed to identify the conditions for a correct utilization of PPGV in evaluating the consequences of sympathetic stimulations. Nine subjects performed three tests: active orthostatic test, slow walk and moderate and exhaustive cycling exercises in the supine position. Pulse waves at the fingertip and RR intervals were recorded at the same time. We used correlations and the Bland and Altman method to compare and evaluate interchangeability between several HRV indices. Bland and Altman analysis highlighted small discrepancies between PPGV and HRV for all HRV indices in the supine position and for LFms2, HFms2, LFpeak and RMSSD in the upright position. During the slow walk, it was impossible to detect properly PPG peaks. We observed large differences between the two methods during the cycling exercise. In conclusion, PPGV can be used instead of HRV without reserve in the supine position but only for some HRV indices in the upright position and not during slow walk and cycling exercise

2009-12-01

167

Office and 24-hour heart rate and target organ damage in hypertensive patients  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background We investigated the association between heart rate and its variability with the parameters that assess vascular, renal and cardiac target organ damage. Methods A cross-sectional study was performed including a consecutive sample of 360 hypertensive patients without heart rate lowering drugs (aged 56 ± 11 years, 64.2% male. Heart rate (HR and its standard deviation (HRV in clinical and 24-hour ambulatory monitoring were evaluated. Renal damage was assessed by glomerular filtration rate and albumin/creatinine ratio; vascular damage by carotid intima-media thickness and ankle/brachial index; and cardiac damage by the Cornell voltage-duration product and left ventricular mass index. Results There was a positive correlation between ambulatory, but not clinical, heart rate and its standard deviation with glomerular filtration rate, and a negative correlation with carotid intima-media thickness, and night/day ratio of systolic and diastolic blood pressure. There was no correlation with albumin/creatinine ratio, ankle/brachial index, Cornell voltage-duration product or left ventricular mass index. In the multiple linear regression analysis, after adjusting for age, the association of glomerular filtration rate and intima-media thickness with ambulatory heart rate and its standard deviation was lost. According to the logistic regression analysis, the predictors of any target organ damage were age (OR = 1.034 and 1.033 and night/day systolic blood pressure ratio (OR = 1.425 and 1.512. Neither 24 HR nor 24 HRV reached statistical significance. Conclusions High ambulatory heart rate and its variability, but not clinical HR, are associated with decreased carotid intima-media thickness and a higher glomerular filtration rate, although this is lost after adjusting for age. Trial Registration ClinicalTrials.gov: NCT01325064

García-García Ángel

2012-03-01

168

Heart Rate Variability and Drawing Impairment in Hypoxemic COPD  

Science.gov (United States)

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…

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

169

Relationship between Exercise Heart Rate and Music Tempo Preference  

Science.gov (United States)

The present study examined the predicted positive and linear relationship (Iwanaga, 1995a, 1995b) between exercise heart rate and music tempo preference. Initially, 128 undergraduate students (M age = 20.0 years, SD = 0.9) were surveyed to establish their three favorite music artists. A separate experimental group of 29 undergraduates (M age =…

Karageorghis, Costas I.; Jones, Leighton; Low, Daniel C.

2006-01-01

170

CNV-Heart Rate Response Under Gradual Sleep Reduction.  

Science.gov (United States)

Four young subjects underwent a gradual reduction of sleep duration. To measure the effects of sleep shortening, heart rate changes were measured with a PDP-12 computer for each and every trial under a fixed fore-period reaction time paradigm. Contingent ...

P. Naitoh R. P. Hilbert

1973-01-01

171

Heart Rate Variability During Early Adaptation to Space  

Science.gov (United States)

A recent report hypothesized that episodes of space motion sickness (SMS) were reliably associated with low frequency oscillations (less than 0.03 to less than 0.01 Hz) in heart rate variability. This paper archives a large data set for review of investigators in this field which may facilitate the evaluation of this hypothesis. Continuous recording of Electro-cardiography (ECG) and other measures were made for 6 to 12 hours per day (waking hours) of six Shuttle crewmembers for the first 3 mission days of two separate Shuttle flights. Spectral analyses of heart rate variability during approximately 200 hours of inflight is presented. In addition, nearly 200 hours of data collected on these same individuals during ground tests prior to the mission are presented. The Purpose of this Publication is to document the incidence of low frequency oscillations of heart rate in 4 people exposed to microgravity over a period of five days. In addition, this report contains spectral analyses of heart rate data collected on these same individuals during ground-based mission simulations. By archiving these data in this manner, it is our intention to make this information available to other investigators interested in studying this phenomena.

Toscano, W. B.; Cowings, P. S.

1994-01-01

172

Practical Implementations of Real-Time Heart Rate Variability.  

Science.gov (United States)

Heart rate variability (HRV) is a useful, non-invasive indicator of autonomic nervous system responsiveness that can be used to signal the need for life-saving interventions, but to date it has not been possible to use it in real-time (RT). Because HRV re...

A. Sastre

2004-01-01

173

Phase plane based identification of fetal heart rate patterns  

Science.gov (United States)

Using a phase plane analysis (PPA) of the spatial spread of trajectories of the fetal heart rate and its time-derivative we characterize the fetal heart rate patterns (fHRP) as defined by Nijhuis. For this purpose, we collect 22 fetal magnetocardiogram using a 151 SQUID system from 22 low-risk fetuses in gestational ages ranging from 30 to 37 weeks. Each study lasted for 30 minutes. After the attenuation of the maternal cardiac signals, we identify the R waves using an adaptive Hilbert transform approach and calculate the fetal heart rate. On these datasets, we apply the proposed approach and the traditionally used approaches such as standard deviation of the normal to normal intervals (SDNN) and root mean square of the successive difference (RMSSD). Heart rate patterns are scored by an expert using Nijhuis criteria and revealed A, B, and D patterns. A receiver operator characteristic (ROC) curve is used to assess the performance of the metric to differentiate the different patterns. Results showed that only PPA was able to differentiate all pairs of fHRP with high performance.

Vairavan, Srinivasan; Sriram, Bhargavi; Wilson, James D.; Preissl, Hubert; Eswaran, Hari

2012-01-01

174

Embryonic Heart Rate correlation with pregnancy outcome in women with first trimester bleeding  

Directory of Open Access Journals (Sweden)

Full Text Available Objective : To assess the correlation between fetal heart rate and the fate of pregnancy in women with first trimester bleeding. Methods : This prospective observational study included 281 consecutive women with first trimester bleeding and Singleton pregnancies. The embryonic heart rate measured at the time of first trans-vaginal scan as per protocol in our university hospital for the evaluation of pregnancy. The heart rate was classified as slow if it was fewer than 110 beats per minute. The primary outcome measure is the occurrence of spontaneous early pregnancy loss prior to 12 weeks. Other outcome measures included the occurrence of late pregnancy loss (prior to 24 weeks, gestational age at birth, and fetal weight at birth. Results : Embryonic heart rate at less than 110 bpm was associated with a high likelihood of pregnancy loss. The sensitivity, specificity, positive and negative predictive value, and accuracy were 43.1%, 86%, 40.7%, 87.2%, and 78.2%, respectively. The OR (95% CI of first-trimester pregnancy. Conclusion: embryonic heart rate can be an independent predictor of the outcome of pregnancy in women with intrauterine pregnancy complaining of first trimester bleeding.

Naemat Mohamed H.ELDin Shiry

2011-10-01

175

Omega-3 Polyunsaturated Fatty Acids and Heart Rate Variability  

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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 arr...

2011-01-01

176

Functionality of the baroreceptor nerves in heart rate regulation  

DEFF Research Database (Denmark)

Two models describing the afferent baroreceptor firing are analyzed, a basic model predicting firing using a single nonlinear differential equation, and an extended model, coupling K nonlinear responses. Both models respond to the the rate (derivative) and the rate history of the carotid sinus arterial pressure. As a result both the rate and the relative level of the carotid sinus arterial pressure is sensed. Simulations with these models show that responses to step changes in pressure follow from the rate sensitivity as observed in experimental studies. Adaptation and asymmetric responses 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 change from sitting to standing and during head-up tilt. The efferent model couples the afferent nerve paths to the sympathetic and parasympathetic outflow, and subsequently predicts the build up of an action potential at the sinus knot of the heart. In this paper, we analyze the nonlinear afferent model and show that the coupled model is able to predict heart rate regulation using blood pressure data as an input.

Ottesen, Johnny T.; Olufsen, Mette

2011-01-01

177

Heart rate detection from an electronic weighing scale  

International Nuclear Information System (INIS)

We propose a novel technique for beat-to-beat heart rate detection based on the ballistocardiographic (BCG) force signal from a subject standing 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 because it uses the load cells in the scale. We have devised an approach to estimate the sensitivity and frequency response of three commercial weighing scales to assess their capability to detect the BCG force signal. Static sensitivities ranged from 490 nV V?1 N?1 to 1670 nV V?1 N?1. The frequency response depended on the subject's mass but it was broad enough for heart rate estimation. We have designed an electronic pulse detection system based on off-the-shelf integrated circuits to sense heart-beat-related force variations of about 0.24 N. The signal-to-noise ratio of the main peaks of the force signal detected was higher than 30 dB. A Bland–Altman plot was used to compare the RR time intervals estimated from the ECG and BCG force signals for 17 volunteers. The error was ±21 ms, which makes the proposed technique suitable for short-term monitoring of the heart rate

2008-08-01

178

Music structure determines heart rate variability of singers  

Science.gov (United States)

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 HR 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.

Vickhoff, Bjorn; Malmgren, Helge; Astrom, Rickard; Nyberg, Gunnar; Ekstrom, Seth-Reino; Engwall, Mathias; Snygg, Johan; Nilsson, Michael; Jornsten, Rebecka

2013-01-01

179

Pathogen-induced heart rate changes associated with cholinergic nervous system activation  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 describ...

Fairchild, Karen D.; Srinivasan, Varadamurthy; Randall Moorman, J.; Gaykema, Ronald P. A.; Goehler, Lisa E.

2011-01-01

180

Some Conclusions  

Science.gov (United States)

How can one be conclusive about something which has not yet happened? How can one come to conclusions about something as insubstantial as the medium-term future? Nonetheless, some common themes have emerged from the Spring Colloquium, as well as from earlier work in the "Teaching 2020" project, which seem to indicate a possible context for the…

Newby, Mike

2005-01-01

 
 
 
 
181

Multi-detector computed tomography to analyze in-stent-restenoses at different heart rates  

International Nuclear Information System (INIS)

Purpose: This study was performed to evaluate the visualization of coronary in-stent restenosis by multi-detector computed tomography (MDCT). Materials and Methods: A restenosis phantom with different stented stenoses was used. The phantom was placed into a dynamic heart phantom with heart rates from 40 to 120 bpm. MDCT was performed with two scan protocols: a standard and an ultra-high resolution scan protocol. Results: Using the ultra-high resolution protocol, artifacts occurred at 0.6 mm around the stent struts (p30% was feasible up to 120 bpm. Conclusion: Multi-detector computed tomography ultra-high resolution scans allowed the assessment of a wide range of degrees of in-stent restenoses. In this experimental setup, standard protocols allowed a discrimination of low, moderate and high-grade stenoses even at heart rates above 100 bpm

2008-09-01

182

COMPARISON OF HEART RATE AND BLOOD PRESSURE CHANGES DURING WALKING AND RUNNING BEFORE AND AFTER TRAINING IN HEALTHY ADULT WOMEN  

Directory of Open Access Journals (Sweden)

Full Text Available AIM: Physical exercise has been associated with heart rate and blood pressure in observational studies and individual clinical trails. The purpose of these study was to asses heart rate and blood pressure changes in healthy adult women students before and after training during walking and running. MATERIALS and METHODS: Fourty healthy women were taken as the subjects. Heart rate and blood pressure recorded before and after training during waking and running. In these study 1600 metres track measured using PCV reel tape was used for walking and running. The durational training programme five months. Every day 15-20 minutes walking and running. RESULT: The examination at parameters BMI, Heart rate, Blood pressure, and SBP, DBP and study statistical analysis was estimated for all subjects. The data were analysed by disruptive and intervention studies. DISCUSION: The finding suggested a significant decrease in heart rate and blood pressure in healthy adult women after training as compared to before training for both during walking and running show that heart rate and blood pressure changes. CONCLUSION: The present study should that physical activity has the ability to decrease the heart rate and arterial blood pressure in healthy adult women. After training physical activity reduce the risk of heart diseases.

Kaarna Munisekhar

2014-06-01

183

Circadian pattern of blood pressure and heart rate in the longer term after heart transplantation.  

Science.gov (United States)

A loss of the circadian rhythm pattern of the blood pressure (BP) and heart rate (HR) as well as the development of hypertension has been found after heart transplantation (Htx). To determine whether a reappearance of this rhythm occurs in the long term after Htx, we used 24-h ambulatory monitoring to study 27 patients 1.7+/-1.6 years (range of 10 days to 4.3 years) after Htx. Patients were divided into two groups: group I (short term), Htx less than 6 months (n = 7); and group 2 (long term), Htx more than 6 months previously (n = 20). Group 2 had significantly higher diastolic BP as well as a greater fall in systolic BP during the night (-0.4+/-8.0 vs. 9.0+/-7.2 mm Hg, p reinervation of the heart, although other neurohumoral factors or concomitant medication (lower steroid dosages) may play a role. PMID:11527142

von Pölnitz, A; Bracht, C; Kemkes, B; Höfling, B

1990-01-01

184

HEART RATE AND ACTIVITY PROFILE FOR YOUNG FEMALE SOCCER  

Directory of Open Access Journals (Sweden)

Full Text Available The physical and physiological demands of high-level male soccer have been studied extensively, while few studies have investigated the demands placed on females during match-play, however, there is no information available about the heart rate and activity profile of young female soccer players during match play. Therefore, the aim of this study was to examine cardiovascular (heart-rates HR and physical demands of young female soccer players during a match. Players were observed during a friendly competitive match (7-a-side over 2 x 25-min halves. Match activities were assessed with Global Position System technology (1Hz. Result showed that young female soccer players attain 88±4.4% and 86.3±4.8% of HRmax during the first and second half respectively (P=0.3, the average heart rate was 87%. During the first and second half, they covered 2072±197 m and 1905±144 m (P13 km/h resulted lower than that previously reported for age-matched male soccer players and elite female soccer players. This seems to indicate that gender and competitive level differences in match physical performance seem to occur mainly in the absolute match work-rate domain.

Granda, J.

2008-07-01

185

Analysis of the work rates and heart rates of association football referees.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This study aimed to describe the work-rate profiles of referees during soccer matches and record heart-rate responses during these games. Using video-recordings 14 referees were observed and their heart rates during the games were monitored by short-range radio telemetry. These included 11 football league matches. The exercise intensity was largely submaximal with a change in activity every 6 s. The mean distance covered during the game was 9.44 km; a significant fall in work rate was noted i...

1993-01-01

186

Modulation of Heart Rate Variability During Severe Hemorrhage at Different Rates in Conscious Rats  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This study was undertaken to evaluate heart rate (HR) regulation during severe hemorrhage (HEM) at different rates of blood loss. Chronically instrumented male rats underwent HEM at one of three rates: slow (0.5 ml/min/kg; S-HEM), intermediate (1.0 ml/min/kg I-HEM), or 2.0 ml/min/kg (fast; F-HEM) until 30% of the estimated total blood volume (ETBV) was withdrawn. Heart rate variability analysis was performed and the absolute power within the low frequency (LF; 0.16-0.6 Hz) and high frequency ...

Porter, Karen; Ahlgren, Joslyn; Stanley, Jessie; Hayward, Linda F.

2009-01-01

187

The predictive value of low heart rate and heart rate variability during stress for reoffending in delinquent male adolescents.  

Science.gov (United States)

Low autonomic (re)activity is a consistent correlate of antisocial behavior in juveniles. However, longitudinal research relating autonomic measures to persistent antisocial behavior has remained scarce. Therefore, in the present study we examined the predictive value of heart rate (HR) and heart rate variability (HRV, often studied as respiratory sinus arrhythmia) for reoffending in delinquent male adolescents. At initial assessment, HR and HRV were measured at rest and in response to a public speaking task. Registered reoffending was assessed after 5-year follow-up. Attenuated HR response and stronger HRV response to stress predicted higher reoffending rates. Results provide evidence that HR/HRV reactivity are neurobiological markers for persistent juvenile antisocial behavior. Although effect sizes were small to moderate, our findings underscore the consistency of the relationship between autonomic markers and antisocial behavior. PMID:21824152

De Vries-Bouw, Marjan; Popma, Arne; Vermeiren, Robert; Doreleijers, Theo A H; Van De Ven, Peter M; Jansen, Lucres M C

2011-11-01

188

Predicting energy expenditures for activities of caribou from heart rates  

Directory of Open Access Journals (Sweden)

Full Text Available Highly significant (P<0.001 linear relationships between oxygen comsumption (VO2 and heart rate (HR were found for six caribou (Rangifer tarandus grand at several times during the year. The standard error of the estimate for predicting VO2 from HR was within 10% of the mean VO2 for 9 of 13 caribou/season combinations. Energy expenditures by caribou while feeding on grain at a trough, grazing, browsing and walking within a large enclosure were 12%, 17%, 18% and 46% higher than the cost of standing. HR's recorded during a given activity decreased sharply during September and October, and reached a minimum in January. An abrupt increase in HR's of female caribou occurred 3 weeks prior to parturition. Heart rate telemetry can be used to determine the relative energy expenditures of free-ranging caribou with reasonable accuracy.

Robert G. White

1986-06-01

189

gHRV: Heart rate variability analysis made easy.  

Science.gov (United States)

In this paper, the gHRV software tool is presented. It is a simple, free and portable tool developed in python for analysing heart rate variability. It includes a graphical user interface and it can import files in multiple formats, analyse time intervals in the signal, test statistical significance and export the results. This paper also contains, as an example of use, a clinical analysis performed with the gHRV tool, namely to determine whether the heart rate variability indexes change across different stages of sleep. Results from tests completed by researchers who have tried gHRV are also explained: in general the application was positively valued and results reflect a high level of satisfaction. gHRV is in continuous development and new versions will include suggestions made by testers. PMID:24854108

Rodríguez-Liñares, L; Lado, M J; Vila, X A; Méndez, A J; Cuesta, P

2014-08-01

190

Low Cost Heart Rate Monitor Using Led-Led Sensor  

Directory of Open Access Journals (Sweden)

Full Text Available A high sensitivity, low power and low cost sensor has been developed for photoplethysmography (PPG measurement. The PPG principle was applied to follow the dilatation and contraction of skin blood vessels during the cardiac cycle. A standard light emitting diodes (LEDs has been used as a light emitter and detector, and in order to reduce the space, cost and power, the classical analogue-to-digital converters (ADCs replaced by the pulse-based signal conversion techniques. A general purpose microcontroller has been used for the implementation of measurement protocol. The proposed approach leads to better spectral sensitivity, increased resolution, reduction in cost, dimensions and power consumption. The basic sensing configuration presented is capable of detecting the PPG signal from a finger or toe, and it is very simple to extract the heart rate and heart rate variability from such a signal.

Ahmed Mahrous Ragib

2009-01-01

191

Correlation of radiation dose and heart rate in dual-source computed tomography coronary angiography  

International Nuclear Information System (INIS)

Background: Computed tomography coronary angiography (CTCA) has been widely used since the introduction of 64-slice scanners and dual-source CT technology, but the relatively high radiation dose remains a major concern. Purpose: To evaluate the relationship between radiation exposure and heart rate (HR), in dual-source CTCA. Material and Methods: Data from 218 CTCA examinations, performed with a dual-source 64-slices scanner, were statistically evaluated. Effective radiation dose, expressed in mSv, was calculated as the product of the dose-length product (DLP) times a conversion coefficient for the chest (mSv = DLPx0.017). Heart rate range and mean heart rate, expressed in beats per minute (bpm) of each individual during CTCA, were also provided by the system. Statistical analysis of effective dose and heart rate data was performed by using Pearson correlation coefficient and two-sample t-test. Results: Mean HR and effective dose were found to have a borderline positive relationship. Individuals with a mean HR >65 bpm observed to receive a statistically significant higher effective dose as compared to those with a mean HR =65 bpm. Moreover, a strong correlation between effective dose and variability of HR of more than 20 bpm was observed. Conclusion: Dual-source CT scanners are considered to have the capability to provide diagnostic examinations even with high HR and arrhythmias. However, it is desirable to keep the mean heart rate below 65 bpm and heart rate fluctuation less than 20 bpm in order to reduce the radiation exposure

2011-04-01

192

Empirical Mode Decomposition Analysis of Heart Rate Variability  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The analysis of heart rate variability (HRV) demands specific capabilities not provided by either parametric or nonparametric spectral estimation methods. Empirical mode decomposition (EMD) has the possibility of dealing with nonstationary and nonlinear embedded phenomena, for a proper assessment of dynamic and transient changes in amplitude and time scales of HRV signal. In this work EMD and a non-linear curve fitting technique are used to study half an hour HRV signal and its intrinsic mode...

2010-01-01

193

Heart Rate Variability Dynamics for the Prognosis of Cardiovascular Risk  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Statistical, spectral, multi-resolution and non-linear methods were applied to heart rate variability (HRV) series linked with classification schemes for the prognosis of cardiovascular risk. A total of 90 HRV records were analyzed: 45 from healthy subjects and 45 from cardiovascular risk patients. A total of 52 features from all the analysis methods were evaluated using standard two-sample Kolmogorov-Smirnov test (KS-test). The results of the statistical procedure provided input to multi-lay...

2011-01-01

194

Point Process Heart Rate Variability Assessment during Sleep Deprivation  

Digital Repository Infrastructure Vision for European Research (DRIVER)

To investigate the potential relationships between Heart rate variability (HRV) and objective performance-subjective alertness measures during sleep deprivation, a novel point process algorithm was applied to ECG data from healthy young subjects in a 52-hour Constant Routine protocol, which includes sleep deprivation. Our algorithm is able to estimate the time-varying behavior of the HRV spectral indexes in an on-line instantaneous fashion. Results demonstrate the ability of our framework to ...

2010-01-01

195

Clinical Application of Heart Rate Variability after Acute Myocardial Infarction  

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Heart rate (HR) variability has been extensively studied in patients surviving an acute myocardial infarction (AMI). The majority of studies have shown that patients with reduced or abnormal HR variability/turbulence have an increased risk of mortality within few years after an AMI. Various measures of HR dynamics, such as time-domain, spectral, and non-linear measures of HR variability, as well as HR turbulence, have been used in risk stratification of post-AMI patients. The prognostic power...

2012-01-01

196

Heart Rate Variability Analysis Using Threshold of Wavelet Package Coefficients  

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In this paper, a new efficient feature extraction method based on the adaptive threshold of wavelet package coefficients is presented. This paper especially deals with the assessment of autonomic nervous system using the background variation of the signal Heart Rate Variability HRV extracted from the wavelet package coefficients. The application of a wavelet package transform allows us to obtain a time-frequency representation of the signal, which provides better insight in the frequency dist...

2009-01-01

197

Assessment and diagnostic applications of heart rate variability  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Though heart rate (HR) is one of the basic parameters in medical diagnostics, precise and reliable assessment of its variability is still an engineering and physiological challenge. Measurement of HR and its changes over time, as in a stress test, is a routine diagnostic procedure to evaluate the cardiovascular condition of a patient. Prenatal monitoring, with its unique problems regarding noninvasive acquisition of reliable fetal data, heavily relies on diagnostic HR analysis.

1993-01-01

198

Increased heart rate and atherosclerosis: Potential implications of ivabradine therapy  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Despite all the therapeutic advances in the field of cardiology, cardiovascular diseases, and in particular coronary artery disease, remain the leading cause of death and disability worldwide, thereby underlining the importance of acquiring new therapeutic options in this field. A reduction in elevated resting heart rate (HR) has long been postulated as a therapeutic approach in the management of cardiovascular disease. An increased HR has been shown to be associated with increased progressio...

Dominguez-rodriguez, Alberto; Blanco-palacios, Gabriela; Abreu-gonzalez, Pedro

2011-01-01

199

Cuff inflation during ambulatory blood pressure monitoring and heart rate  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Mia Skov-Madsen, My Svensson, Jeppe Hagstrup ChristensenDepartment of Nephrology, Aarhus University Hospital, Aalborg, DenmarkIntroduction: Twenty four-hour ambulatory blood pressure monitoring is a clinically validated procedure in evaluation of blood pressure (BP). We hypothesised that the discomfort during cuff inflation would increase the heart rate (HR) measured with 24-h ambulatory BP monitoring compared to a following HR measurement with a 24-h Holter monitor.Methods: The study populat...

Mia Skov-Madsen; My Svensson; Jeppe Hagstrup Christensen

2008-01-01

200

Scientific Comparison of Different Online Heart Rate Monitoring Systems  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Recent technical development focused on real-time heart rate monitoring instead of postexercise evaluation of recorded data. There are several systems on the market that allow direct and real-time monitoring of several individuals at the same time. The present study compared the systems of Polar, Acentas, Activio, and Suunto in a field test with twelve subjects regarding failure quota, operating distance, and ECG validity. Moreover, the installation and use of software and hardware were evalu...

Scho?nfelder, Martin; Hinterseher, Georg; Peter, Philipp; Spitzenpfeil, Peter

2011-01-01

 
 
 
 
201

Heart rate variability related to effort at work.  

Science.gov (United States)

Changes in autonomic nervous system function have been related to work stress induced increases in cardiovascular morbidity and mortality. Our purpose was to examine whether various heart rate variability (HRV) measures and new HRV-based relaxation measures are related to self-reported chronic work stress and daily emotions. The relaxation measures are based on neural network modelling of individual baseline heart rate and HRV information. Nineteen healthy hospital workers were studied during two work days during the same work period. Daytime, work time and night time heart rate, as well as physical activity were recorded. An effort-reward imbalance (ERI) questionnaire was used to assess chronic work stress. The emotions of stress, irritation and satisfaction were assessed six times during both days. Seventeen subjects had an ERI ratio over 1, indicating imbalance between effort and reward, that is, chronic work stress. Of the daily emotions, satisfaction was the predominant emotion. The daytime relaxation percentage was higher on Day 2 than on Day 1 (4 ± 6% vs. 2 ± 3%, p < 0.05) and the night time relaxation (43 ± 30%) was significantly higher than daytime or work time relaxation on the both Days. Chronic work stress correlated with the vagal activity index of HRV. However, effort at work had many HRV correlates: the higher the work effort the lower daytime HRV and relaxation time. Emotions at work were also correlated with work time (stress and satisfaction) and night time (irritation) HRV. These results indicate that daily emotions at work and chronic work stress, especially effort, is associated with cardiac autonomic function. Neural network modelling of individual heart rate and HRV information may provide additional information in stress research in field conditions. PMID:21356531

Uusitalo, Arja; Mets, Terhi; Martinmäki, Kaisu; Mauno, Saija; Kinnunen, Ulla; Rusko, Heikki

2011-11-01

202

The Effect of Mindfulness on Heart Rate Control  

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An experiment was conducted to test the hypothesis that mindful attention to change regarding heart rate (HR) would result in greater control over HR. Experimental groups monitored the changing or stable nature of HR, respectively. All participants' HR slowed during the decrease phase. Participants whose attention was directed to the stable nature of HR performed the worst on the increase phase of the HR control task. These results suggest that mindfulness, instantiated here as attention to v...

Williams, Ryan P.; Delizonna, Laura L.; Langer, Ellen

2009-01-01

203

QT intervals and heart rate variability in hypertensive patients.  

Science.gov (United States)

Low heart rate variability and increased QT dispersion are risk factors for cardiac mortality in various patient populations. We studied dispersion of QT interval, i.e. an index of inhomogeneity of repolarization, and heart rate variability (HRV) i.e., a measure of cardiac autonomic modulation in 76 essential hypertension cases (45 women, 53.0 +/- 11.1 years, body mass index: 25.1 +/- 1.4 kg/m2) and 70 healthy cases (42 women, 54.0 +/- 10.2 years, body mass index: 25.5 +/- 1.6 kg/m2, p > 0.05). QT-corrected QT intervals and their dispersions were significantly higher in the hypertensive group (p ventricular mass index and high Lown grade ventricular rhythm problems. Time domain measures like standard deviation of RR intervals, standard deviation of the means of all corrected RR intervals calculated at 5 min intervals (p intervals differing by > 50 msec (p = 0.005), HRV triangular index (p = 0.007), the square root of the mean squared differences of successive RR intervals (p = 0.011), and the high frequency (HF, 0.16-0.40 Hz, p ventricular rhythm problems, whereas LF and LF / HF showed direct relations with high levels of systolic and diastolic blood pressures and high Lown grade ventricular rhythm problems. The measures of heart rate variability apart from LF and LF / HF were inversely related with the QT intervals and dispersions, whereas LF / HF was directly related with them. Therefore, we conclude that the levels of both systolic and diastolic blood pressures are related to the generation of ventricular rhythm problems either via increasing left ventricular mass which results in an increase in QT parameter measurements, or by altering heart rate variability measures indicating a disturbance in cardiac autonomic balance in essential hypertension. PMID:10850533

Kaftan, A H; Kaftan, O

2000-03-01

204

Peripheral oxygen saturation, heart rate, and blood pressure during dental treatment of children with cyanotic congenital heart disease  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english OBJECTIVES: In this observational study, we evaluated the peripheral oxygen saturation (SpO2), heart rate, and blood pressure of children with cyanotic congenital heart disease who were undergoing dental extraction. METHODS: Forty-four patients between the ages of 6 and 12 years who underwent upp [...] er primary tooth extraction were included in the study. Of these, 20 patients were in the cyanotic congenital heart disease group and 24 were in the control group. RESULTS: Peripheral oxygen saturation, heart rate, and systolic blood pressure in the cyanotic congenital heart disease group varied quite significantly during the treatment protocol (p

Rosane Menezes Faria, Dutra; Itamara Lucia Itagiba, Neves; Ricardo Simões, Neves; Edmar, Atik; Ubiratan de Paula, Santos.

205

Heart Rate Variability and Nonlinear Dynamics in Risk Stratification  

Directory of Open Access Journals (Sweden)

Full Text Available The time domain measures and power spectral analysis of heart rate variability (HRV are classic conventional methods to assess the complex regulatory system between autonomic nervous system and heart rate and are most widely used. There are abundant scientific data about the prognostic significance of the conventional measurements of HRV in patients with various conditions, particularly with myocardial infarction. Some studies have suggested that some newer measures describing nonlinear dynamics of heart rate, such as fractal measures, may reaveal prognostic information beyond that obtained by the conventional measures of HRV. An ideal risk indicator could specifically predict sudden arrhythmic death as the implantable cardioverter-defibrillator (ICD therapy can prevent such events. In postinfarction patients, numerically the highest number of sudden deaths occur in patients with better preserved left ventricular function than in those with severe left ventricular dysfunction. Recent data support the concept that HRV measurements, when analyzed several weeks after acute myocardial infarction, predict life-threatening ventricular tachyarrhythmias in patients with moderately depressed left ventricular function. However, well-designed prospective randomized studies are needed to evaluate whether the ICD therapy based on the assessment of HRV alone or with other risk indicators improves the patients´ prognosis. Several issues, such as the optimal target population, optimal timing of HRV measurements, optimal methods of HRV analysis and optimal cutpoints for different HRV parameters, need clarification before the HRV analysis can be a widespread clinical tool in risk stratification.

JuhaPerkiömäki

2011-11-01

206

Heart rate variability in patients with Sjögren's syndrome.  

Science.gov (United States)

Heart rate variability (HRV) gives information about sympathetic parasympathetic autonomic balance. Our purpose was to determine whether HRV is abnormal in patients with Sjögren's syndrome. In 16 patients with Sjögren's syndrome and 30 matched controls, a short time analysis of HRV was performed for both the frequency and the time domain. In the time domain, patients tended to display a slower heart rate, greater R-R variability and higher standard deviation of the mean (SDNN) than did healthy subjects, but the differences were not statistically significant. In the frequency domain the spectral measures of HRV showed a slight reduction of LF and an increase of HF; as a result, the ratio between high and low frequencies, representative of sympathovagal modulation, was significantly reduced. Our data suggest an increase in the parasympathetic control of heart rate in patients with Sjögren's syndrome. This predominance in vagal tone could exert a protective and antiarrhythmic role in patients with primary Sjögren's syndrome, and may be relevant with reference to the lower incidence of sudden death in this disorder compared to other major autoimmune diseases. PMID:11147760

Tumiati, B; Perazzoli, F; Negro, A; Pantaleoni, M; Regolisti, G

2000-01-01

207

Automated diagnosis of diabetes using heart rate variability signals.  

Science.gov (United States)

An automated diagnostic system for diabetes mellitus (DM), from heart rate variability (HRV) measures, using feed forward neural network has been developed. Changes in autonomic nervous system activity caused by DM are quantified by means of time domain and frequency domain analysis of HRV. Electrocardiograms of 70 DM patients and 65 healthy volunteers were recorded. Nine time domain measures-standard deviation of all NN intervals, square root of mean of sum of squares of differences between adjacent NN interval (RMSSD), number of adjacent NN intervals differing more than 50 ms. (NN50 count), percentage of NN50 count, R-R triangular index, triangular interpolation of NN intervals (TINN), standard deviation of the mean heart rate, mean R-R interval and mean heart rate-were used as the input features to the neural network. This diagnostic system classifies DM patients and normal volunteers from morphologically identical ECGs. Diagnostic results show that the system is performing well with an accuracy of 93.08%, specificity of 96.92% and sensitivity of 89.23%. PMID:21271353

P T, Ahamed Seyd; Joseph, Paul K; Jacob, Jeevamma

2012-06-01

208

Impaired post exercise heart rate recovery in anabolic steroid users.  

Science.gov (United States)

Previous study showed that muscle sympathetic nerve activity (MSNA) was augmented in anabolic steroids users (AASU). In the present study, we tested the hypothesis that the heart rate (HR) responses after maximal exercise testing would be reduced in AASU. 10 male AASU and 10 AAS nonusers (AASNU) were studied. Cardiopulmonary exercise was performed to assess the functional capacity and heart rate recovery. MSNA was recorded directly from the peroneal nerve by microneurography technique. Peak oxygen consumption (VO?) was lower in AASU compared to AASNU (43.66±2.24 vs. 52.70±1.68 ml/kg/min, P=0.005). HR recovery (HRR) at first and second minute was lower in AASU than AASNU (21±2 vs. 27±2 bpm, P=0.02 and 37±4 vs. 45±2 bpm, P=0.05, respectively). MSNA was higher in AASU than AASNU (29±3 vs. 20±1 bursts/min, P=0.01). Further analysis showed a correlation between HRR and MSNA (r=- 0.64, P=0.02), HRR at first minute and peak VO? (r=0.70, P=0.01) and HRR at second minute and peak VO? (r=0.62, P=0.02). The exacerbated sympathetic outflow associated with a lower parasympathetic activation after maximal exercise, which impairs heart rate recovery, strengthens the idea of autonomic imbalance in AASU. PMID:23606338

dos Santos, M R; Dias, R G; Laterza, M C; Rondon, M U P B; Braga, A M F W; de Moraes Moreau, R L; Negrão, C E; Alves, M-J N N

2013-10-01

209

Electron-beam CT coronary angiography in the patients with high heart rate arrhythmia or pacemaker  

International Nuclear Information System (INIS)

Objective: To report the clinical applicability of coronary angiography for patients with high heart rate, arrhythmia or cardiac pacing using the new-generation of electron-beam CT (e-Speed). Methods: EBCT (GE e-Speed) coronary angiography was performed in 36 eases (male 27, female 9, mean age 58), including the heart rate more than 90 bpm in 20 patients, frequent ectopic beats in 11 cases, implantation of cardiac pacemaker in 4 patients and the unacceptable MSCT image quality due to variability of interscan heart rate (from 82 bpm to 104 bpm) in 1 case. After volume data set was acquired using spiral mode with prospective ECG-gating, the reconstructions of MIP, CPR, VR and Cine were performed. The VR quality was evaluated using a five-point scale. Results: The quality of coronary imaging in all of 36 cases were acceptable. The total visualization rate of coronary artery branches was 80.0%. Left main, left anterior artery and right coronary artery were visualized in all patients and in 94.3% of all cases circumflex artery were visible. Conclusion: EBCT (e-Speed) is applicable in noninvasive coronary angiography for patients with high heart rate, arrhythmia or implanted cardiac pacemaker', and this examination can obtain satisfied diagnosis. (authors)

2006-03-01

210

10 Conclusion  

10 Conclusion The role of regional trade integration in conflict prevention ...being pursued behind closed doors in bilateral and regional agreements rather than under the uncomfortable glare of ...help to manage disagreements between countries and that trade integration can bind countries’ divergent national interests to a

211

Drawing Conclusions  

Science.gov (United States)

Drawing conclusions involves comparing initial ideas with new evidence and then deciding whether the ideas fit or need to be changed. It is the key to the investigation, where mental and practical activity comes together. This is how scientists approach i

Klentschy, Michael P.

2008-04-01

212

256-slice CT coronary angiography in atrial fibrillation: The impact of mean heart rate and heart rate variability on image quality  

Science.gov (United States)

The aim of this study was to evaluate the image quality of 256-MDCT in atrial fibrillation and to compare the findings with those among patients in sinus rhythm.MaterialsAll reconstructed images were evaluated by two independent experienced readers blinded to patient information, heart rate, and ECG results to assess the diagnostic quality of images of the coronary artery segments using axial images, multi-planar reformations, maximum intensity projections, and volume rendering technique.ResultsNo statistical significance was detected in terms of the overall image quality between patients in sinus rhythm and with atrial fibrillation. Pearson's correlation analysis showed no significant association between image quality and mean heart rate no matter for patients in sinus rhythm or with atrial fibrillation. Similarly, there was no correlation between image quality and heart rate variability for either patients in sinus rhythm or with atrial fibrillation. Our results showed that the optimal reconstruction window depends on patient's HR, and the pattern for patients in atrial fibrillation is similar to that obtained from non-atrial fibrillation patients.ConclusionThis study shows the potential of using 256-MDCT coronary angiography in patients with atrial fibrillation. Our results suggest that when appropriate reconstruction timing window is applied, patients with atrial fibrillation do not have to be excluded from MDCT coronary angiographic examinations.

Chen, Liang-Kuang; Hsu, Shih-Ming; Mok, Greta S. P.; Law, Wei-Yip; Lu, Kun-Mu; Yang, Ching-Ching; Wu, Tung-Hsin

2011-08-01

213

256-slice CT coronary angiography in atrial fibrillation: The impact of mean heart rate and heart rate variability on image quality  

International Nuclear Information System (INIS)

Objective: The aim of this study was to evaluate the image quality of 256-MDCT in atrial fibrillation and to compare the findings with those among patients in sinus rhythm. Materials: All reconstructed images were evaluated by two independent experienced readers blinded to patient information, heart rate, and ECG results to assess the diagnostic quality of images of the coronary artery segments using axial images, multi-planar reformations, maximum intensity projections, and volume rendering technique. Results: No statistical significance was detected in terms of the overall image quality between patients in sinus rhythm and with atrial fibrillation. Pearson's correlation analysis showed no significant association between image quality and mean heart rate no matter for patients in sinus rhythm or with atrial fibrillation. Similarly, there was no correlation between image quality and heart rate variability for either patients in sinus rhythm or with atrial fibrillation. Our results showed that the optimal reconstruction window depends on patient's HR, and the pattern for patients in atrial fibrillation is similar to that obtained from non-atrial fibrillation patients. Conclusion: This study shows the potential of using 256-MDCT coronary angiography in patients with atrial fibrillation. Our results suggest that when appropriate reconstruction timing window is applied, patients with atrial fibrillation do not have to be excluded from MDCT coronary angiographic examinations.

2011-08-21

214

256-slice CT coronary angiography in atrial fibrillation: The impact of mean heart rate and heart rate variability on image quality  

Energy Technology Data Exchange (ETDEWEB)

Objective: The aim of this study was to evaluate the image quality of 256-MDCT in atrial fibrillation and to compare the findings with those among patients in sinus rhythm. Materials: All reconstructed images were evaluated by two independent experienced readers blinded to patient information, heart rate, and ECG results to assess the diagnostic quality of images of the coronary artery segments using axial images, multi-planar reformations, maximum intensity projections, and volume rendering technique. Results: No statistical significance was detected in terms of the overall image quality between patients in sinus rhythm and with atrial fibrillation. Pearson's correlation analysis showed no significant association between image quality and mean heart rate no matter for patients in sinus rhythm or with atrial fibrillation. Similarly, there was no correlation between image quality and heart rate variability for either patients in sinus rhythm or with atrial fibrillation. Our results showed that the optimal reconstruction window depends on patient's HR, and the pattern for patients in atrial fibrillation is similar to that obtained from non-atrial fibrillation patients. Conclusion: This study shows the potential of using 256-MDCT coronary angiography in patients with atrial fibrillation. Our results suggest that when appropriate reconstruction timing window is applied, patients with atrial fibrillation do not have to be excluded from MDCT coronary angiographic examinations.

Chen, Liang-Kuang [Department of Radiology, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan (China); College of Medicine, Fu Jen Catholic University, Taipei, Taiwan (China); Hsu, Shih-Ming [Department of Biomedical Imaging and Radiological Science, China Medical University, Taichung, Taiwan (China); Mok, Greta S.P. [Department of Electrical and Electronics Engineering, Faculty of Science and Technology, University of Macau, Macau (China); Law, Wei-Yip; Lu, Kun-Mu [Department of Radiology, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan (China); Yang, Ching-Ching, E-mail: g39220003@yahoo.com.tw [Department of Radiological Technology, Tzu Chi College of Technology, 880, Sec.2, Chien-kuo Rd. Hualien 970, Taiwan (China); Wu, Tung-Hsin, E-mail: tung@ym.edu.tw [Department of Biomedical Imaging and Radiological Sciences, National Yang Ming University, 155 Li-Nong St., Sec. 2, Taipei 112, Taiwan (China)

2011-08-21

215

Effect of meditation on scaling behavior and complexity of human heart rate variability  

CERN Document Server

The heart beat data recorded from samples before and during meditation are analyzed using two different scaling analysis methods. These analyses revealed that mediation severely affects the long range correlation of heart beat of a normal heart. Moreover, it is found that meditation induces periodic behavior in the heart beat. The complexity of the heart rate variability is quantified using multiscale entropy analysis and recurrence analysis. The complexity of the heart beat during mediation is found to be more.

Sarkar, A

2006-01-01

216

Skinfold thickness is related to cardiovascular autonomic control as assessed by heart rate variability and heart rate recovery.  

Science.gov (United States)

The purpose of this study was to determine if heart rate recovery (HRR) and heart rate variability (HRV) are related to maximal aerobic fitness and selected body composition measurements. Fifty men (age = 21.9 ± 3.0 years, height = 180.8 ± 7.2 cm, weight = 80.4 ± 9.1 kg, volunteered to participate in this study. For each subject, body mass index (BMI), waist circumference (WC), and the sum of skinfolds across the chest, abdomen, and thigh regions (SUMSF) were recorded. Heart rate variability (HRV) was assessed during a 5-minute period while the subjects rested in a supine position. The following frequency domain parameters of HRV were recorded: normalized high-frequency power (HFnu), and low-frequency to high-frequency power ratio (LF:HF). To determine maximal aerobic fitness (i.e., VO2max), each subject performed a maximal graded exercise test on a treadmill. Heart rate recovery was recorded 1 (HRR1) and 2 (HRR2) minutes during a cool-down period. Mean VO2max and BMI for all the subjects were 49.5 ± 7.5 ml·kg(-1)·min(-1) and 24.7 ± 2.2 kg·m(-2), respectively. Although VO2max, WC, and SUMSF was each significantly correlated to HRR and HRV, only SUMSF had a significant independent correlation to HRR1, HRR2, HFnu, LF:HF (p < 0.01). The results of the regression procedure showed that SUMSF accounted for the greatest variance in HRR1, HRR2, HFnu, and LF:HF (p < 0.01). The results of this study suggest that cardiovascular autonomic modulation is significantly related to maximal aerobic fitness and body composition. However, SUMSF appears to have the strongest independent relationship with HRR and HRV, compared to other body composition parameters and VO2max. PMID:21691230

Esco, Michael R; Williford, Henry N; Olson, Michele S

2011-08-01

217

Heart rate variability in patients with chronic cerebral ischemia  

Directory of Open Access Journals (Sweden)

Full Text Available The purpose of the work is to estimate the status of autonomic nervous system in patients with chronic cerebral ischemia by means of the analysis of heart rate variability at various stages of disease. 120 patients with chronic cerebral ischemia aged from 45 to 65 took part in the research. The comparison group included 30 patients with an arterial hypertension and without chronic cerebral ischemia. Heart rate variability analisis included time-domain and frequency-domain methods of five-minute sequence of the electrocardiographic intervals registered in at rest and in or-thostatic probe. The results of research have shown, that autonomic disorders with prevalence of sympathetic nervous system accompany initial implications of chronic cerebral ischemia. The second stage of disease is characterized by depression of activity of both autonomic, and central regulation. The expressed depression of autonomic maintenance of regulation of heart rhythm of both from sympathetic, and from parasympathetic nervous system was observed at the third stage of chronic cerebral ischemia

Smyshlaeva ?.?.

2010-12-01

218

BREAKDOWN OF SCALING PROPERTIES IN ABNORMAL HEART RATE VARIABILITY  

Directory of Open Access Journals (Sweden)

Full Text Available The heart rate variability (HRV of subjects with normal sinus rhythm (NSR and subjects with congestive heart failure(CHF is compared by using a structure function borrowed from turbulence studies. Firstly, it is shown that the HRV ofsubjects with NSR displays a power law scaling property, which indicates the presence of structured heartbeat controlmechanisms. Secondly, it is found that such a scaling property is partially lost for subjects with CHF. The absence ofscaling properties is associated to the presence of uncorrelated (i.e., noise-like heart rate variations. In order to gaininsights on the source of the scaling property, the HRV is analyzed from a systemic (i.e., feedback control viewpoint inthe frequency domain. It is found that the HRV of subjects with NSR is governed by a stable adaptive control mechanismpresumably located in the autonomic nervous system. In the case of subjects with CHF, the results show that thisregulation mechanism is partially or totally absent, which is interpreted as the cause of the breakdown of the scalinglaw property.

Rodríguez, E.

2006-04-01

219

Association between the Rating Perceived Exertion, Heart Rate and Blood Lactate in Successive Judo Fights (Randori  

Directory of Open Access Journals (Sweden)

Full Text Available 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, P<0.05; (2 ?CR-10 and ?[La] (T1-T2: r = .71, P< 0.05; T2-T3: r =0.92, P<0.01; T3-T4: r =0.73, P<0.05. Moreover, significant differences were noted in the behavior of the HR between the 2nd (T2 and 3rd (T3 judo fight simulations (P<0.05.Conclusion: The use of CR-10 in the evaluation process, as well as in deciding the load of training in judo, should be done with caution

Braulio Henrique Magnani Branco

2013-06-01

220

Evaluation of the heart rate and arrhythmias following the Maze procedure for chronic atrial fibrillation  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english PURPOSE: To assess the presence and the prevalence of arrhythmias and the variability of the heart rate in the medium-term postoperative period following the maze procedure for chronic atrial fibrillation (AF). METHODS: Seventeen patients with a mean age of 51.7±12.9 years, who previously underwent [...] the maze procedure without cryoablation for chronic atrial fibrillation, were evaluated with the 24 hour electrocardiogram (ECG) - Holter monitoring from the 6th month after the operation. Valvular and coronary procedures were concomitantly performed. RESULTS: The mean heart rate during Holter monitoring was 82±8bpm; the maximal heart rate was 126 ± 23bpm and the minimal heart rate 57±7bpm. Sinus rhythm was found in 10 (59%) patients and atrial rhythm was found in 7 (41%). Supraventricular extrasystoles had a rate of 2.3±5.5% of the total number of heartbeats and occurred in 16 (94%) patients. Six (35%) patients showed nonsustained atrial tachycardia. Ventricular extrasystoles, with a rate of 0.8±0.5% of the total heartbeats, occurred in 14 (82%) patients. The chronotropic competence was normal in 9 (53%) patients and attenuated in 8 (47%). The atrioventricular conduction (AV) was unchanged in 13 (76%) patients and there were 4 (24%) cases of first degree atrioventricular block (AVB). CONCLUSION: After the maze procedure, the values for the mean heart rate, AV conduction and chronotropic competence approach the normal range, although some cases show attenuation of the chronotropic response, first degree AV block or benign arrhythmias.

Cunha, Bartira; Kalil, Renato A. K.; Albrecht, Álvaro S.; Lima, Gustavo G.; Kruse, José Cláudio L..

 
 
 
 
221

Study of foetal heart rate patterns in pregnancy with intra-uterine growth restriction during antepartum period  

International Nuclear Information System (INIS)

Objectives: To evaluate foetal heart rate pattern during antepartum period in pregnancies suffering from intra-uterine growth restriction. Methods: The case control study was conducted at the Alzahra Hospital, Tabriz, Iran from April 2008 to April 2011. It comprised 100 pregnancies with intra-uterine growth restriction and 92 normal pregnancies. The foetal heart rate pattern including basal heart rate, beat-to-beat variation, non-stress test (NST) result and acceleration and deceleration patterns of the heart rate were determined in both groups during the antepartum period. Findings were compared between the two groups and their relation with pregnancy-foetal outcomes was specified in the case group. SPSS 15 was used for statistical analysis. Results: There was no statistically significant difference between the foetus mean basal heart rate in the two groups (p <0.960). Frequency of cases with non-reactive non-stress test in the Cases was significantly higher than Controls (p <0.005). The difference in heart rate acceleration was also not statistically significant (p <0.618). Frequency of cases with low birth weight and caesarian was non-significantly but borderline higher among the Cases (p <0.081 and 0.060, respectively). Conclusion: Abnormal foetal heart rate pattern is more common in pregnancies marked by intra-uterine growth restriction and is directly associated with worse pregnancy/foetal outcomes. (author)

2013-07-01

222

General conclusions  

International Nuclear Information System (INIS)

In conclusion, a general consensus of a number of points which the author endeavours to summarize in this article: -doctors are an excellent channel for passing on information to the public -doctors feel that they do not know enough about the subject and a training on radiobiology and radiation protection is a necessity for them -communication between doctors and the general public is poor in this field -research should be encouraged in numerous areas such as: carcinogenic effect of low doses of radiation, pedagogy and risk perception

1993-01-01

223

Analysis of heart rate variability using fuzzy measure entropy.  

Science.gov (United States)

This paper proposed a new entropy measure, Fuzzy Measure Entropy (FuzzyMEn), for the analysis of heart rate variability (HRV) signals. FuzzyMEn was calculated based on the fuzzy set theory and improved the poor statistical stability in the approximate entropy (ApEn) and sample entropy (SampEn). The simulation results also demonstrated that the FuzzyMEn had better algorithm discrimination ability when compared with the recently published fuzzy entropy (FuzzyEn), The validity of FuzzyMEn was tested for clinical HRV analysis on 120 subjects (60 heart failure and 60 healthy control subjects). It is concluded that FuzzyMEn could be considered as a valid and reliable method for a clinical HRV application. PMID:23273774

Liu, Chengyu; Li, Ke; Zhao, Lina; Liu, Feng; Zheng, Dingchang; Liu, Changchun; Liu, Shutang

2013-02-01

224

Usefulness of the heart-rate variability complex for predicting cardiac mortality after acute myocardial infarction  

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Background Previous studies indicate that decreased heart-rate variability (HRV) is related to the risk of death in patients after acute myocardial infarction (AMI). However, the conventional indices of HRV have poor predictive value for mortality. Our aim was to develop novel predictive models based on support vector machine (SVM) to study the integrated features of HRV for improving risk stratification after AMI. Methods A series of heart-rate dynamic parameters from 208 patients were analyzed after a mean follow-up time of 28 months. Patient electrocardiographic data were classified as either survivals or cardiac deaths. SVM models were established based on different combinations of heart-rate dynamic variables and compared to left ventricular ejection fraction (LVEF), standard deviation of normal-to-normal intervals (SDNN) and deceleration capacity (DC) of heart rate. We tested the accuracy of predictors by assessing the area under the receiver-operator characteristics curve (AUC). Results We evaluated a SVM algorithm that integrated various electrocardiographic features based on three models: (A) HRV complex; (B) 6 dimension vector; and (C) 8 dimension vector. Mean AUC of HRV complex was 0.8902, 0.8880 for 6 dimension vector and 0.8579 for 8 dimension vector, compared with 0.7424 for LVEF, 0.7932 for SDNN and 0.7399 for DC. Conclusions HRV complex yielded the largest AUC and is the best classifier for predicting cardiac death after AMI.

2014-01-01

225

Time Domain Measures of Heart Rate Variability to Assess Autonomic Dysfunction In Irritable Bowel Syndrome  

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Full Text Available AbstractBackground: Autonomic nerve function impairment is related to development of Irritable Bowel Syndrome (IBS. Time domain measures of Heart rate variability (HRV is a useful tool to measure autonomic nerve function activity.Objective: To assess autonomic nerve function activity by time domain measures of heart rate variability in patients with Irritable Bowel Syndrome.Methods: This cross sectional study was conducted in the Department of Physiology, Bangabandhu Sheikh Mujib Medical University (BSMMU, Dhaka in 2011. Ninety patients aged 20-50 years of both sex with Irritable bowel syndrome were included in the study group. They were collected from the OPD of Gastroenterology in BSMMU. Age and sex matched 30 apparently healthy subjects served as control. For assessing HRV by time domain method, Mean heart rate Mean R-R interval, Max/Min R-R interval, SDNN, RMSSD, PNN50%, NN50% were recorded by a digital Polyrite. ANOVA, independent sample t-test and Pearson’s correlation coefficient tests were performed as applicable.Results: Mean heart rate were significantly higher and Mean R-R interval, Max/Min R-R interval, SDNN, RMSSD, PNN50%, NN50% were significantly lower in IBS groups compared to those of control. Correlation analysis showed negative correlations of SDNN, RMSSD, PNN50%, NN50% with duration of disease.Conclusion: This study concludes that parasympathetic activity was reduced in patients of IBS. In addition, decreased vagal modulation is inversely related to the duration IBS.

Mohammad Nayem, Noorzahan Begum, Sultana Ferdousi

2012-12-01

226

Bilateral Hegu Acupoints Have the Same Effect on the Heart Rate Variability of the Healthy Subjects  

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Background. The specificity of acupuncture points (acupoints) is one of the key concepts in traditional acupuncture theory, but the question of whether there is adequate scientific evidence to prove or disprove specificity has been vigorously debated in recent years. Acupoint laterality is an important aspect of acupoint specificity. Data is particularly scarce regarding the laterality of the same channel, namesake acupoint located on opposite sides of the body. Our previous study results suggest that Neiguan acupoint (PC6) has the laterality. The aim of this study was to investigate whether Hegu (LI4) also has laterality from the perspective of heart rate variability. Methods. A total of twenty-eight healthy female volunteers were recruited for this study and were randomly separated into the group I (n = 14) and the group II (n = 14) according to the register order. In the group I, left LI4 was stimulated in the first epoch and the right LI4 was stimulated in the second epoch. In the group II, right LI4 was stimulated in the first epoch and left LI4 was stimulated in the second epoch. Electrocardiogram was recorded and heart rate variability was analyzed. Results. The results show that there were no significant differences of heart rate variablity between the group I and the group II in the time domain and in the frequency domain. Conclusions. Bilateral Hegu acupoints have the same effect on the heart rate variability of the healthy subjects.

Yuying, Tian; Shuyong, Jia; Wenting, Zhou; Weibo, Zhang

2014-01-01

227

Genome-wide association analysis identifies multiple loci related to resting heart rate  

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Higher resting heart rate is associated with increased cardiovascular disease and mortality risk. Though heritable factors play a substantial role in population variation, little is known about specific genetic determinants. This knowledge can impact clinical care by identifying novel factors that influence pathologic heart rate states, modulate heart rate through cardiac structure and function or by improving our understanding of the physiology of heart rate regulation. To identify common ge...

2010-01-01

228

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

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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.

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; Heijer, Martin Den; 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, S?ren; Chanock, Stephen J; Chines, Peter S; Chung, Mina; Darbar, Dawood; Dina, Christian; Dorr, 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; Kaab, Stefan; Kanon, Bart; Ketkar, Shamika; Khaw, Kay-Tee; Knowles, Joshua W; Kooner, Angrad S; Kors, Jan A; Kumari, Meena; Milani, Lili; Laiho, Paivi; 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; Leach, Irene Mateo; McArdle, Wendy L; McCarroll, Steven A; Medland, Sarah E; Miller, Kathryn A; Montgomery, Grant W; Morrison, Alanna C; Muller-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

2013-01-01

229

[A DSP-based design method for detecting fetal heart rate signals].  

Science.gov (United States)

The paper presents the development and design of an ultrasonic Doppler fetal heart rate monitoring system based on DSP, and explains the realization of a algorithm for detecting fetal heart rate. Clinical practice has proved that this system is able to pick up the real-time fetal heart rate correctly and rapidly. PMID:17300006

Yang, Xiao-feng; Li, Peng; Zhang, Da-long; Bian, Zheng-zhong

2006-11-01

230

Dynamic analysis of heart rate may predict subsequent ventricular tachycardia after myocardial infarction  

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Dynamics analysis of RR interval behavior and traditional measures of heart rate variability were compared between postinfarction patients with and without vulnerability to ventricular tachyarrhythmias in a case-control study. Short-term fractal correlation of heart rate dynamics was better than traditional measures of heart rate variability in differentiating patients with and without life-threatening arrhythmias.

Makikallio, T. H.; Seppanen, T.; Airaksinen, K. E.; Koistinen, J.; Tulppo, M. P.; Peng, C. K.; Goldberger, A. L.; Huikuri, H. V.

1997-01-01

231

Optimum Heart Rate to Minimize Pulsatile External Cardiac Power  

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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.

Pahlevan, Niema; Gharib, Morteza

2011-11-01

232

Omega-3 Polyunsaturated Fatty Acids and Heart Rate Variability  

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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

JeppeHagstrupChristensen

2011-11-01

233

Noisy fluctuation of heart rate indicates cardiovascular system instability.  

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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 < 0.01) in healthy subjects (n = 12). Head-up position also decreased nyHRV in patients without vasovagal symptoms (n = 24; 0.220 ± 0.058 vs. 0.034 ± 0.015, p < 0.05), but not in patients with vasovagal symptoms during a head-up tilt table test (age and sex paired, 0.103 ± 0.041 vs. 0.122 ± 0.069, not significant). Heart rate variability includes a physiological non-harmonic non-fractal noisy fluctuation. This noisy fluctuation indicates low engagement of regulatory mechanisms because it disappears when the 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. PMID:23652709

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

2013-09-01

234

Multi-detector computed tomography to analyze in-stent-restenoses at different heart rates  

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Purpose: This study was performed to evaluate the visualization of coronary in-stent restenosis by multi-detector computed tomography (MDCT). Materials and Methods: A restenosis phantom with different stented stenoses was used. The phantom was placed into a dynamic heart phantom with heart rates from 40 to 120 bpm. MDCT was performed with two scan protocols: a standard and an ultra-high resolution scan protocol. Results: Using the ultra-high resolution protocol, artifacts occurred at 0.6 mm around the stent struts (p<0.001). Artifacts compromised the discrimination between no stenosis and low-grade stenosis. Approximately 73% of the central lumen diameter was able to be assessed without limiting artifacts allowing the discrimination of no or low vs. moderate and high-grade stenoses (p<0.05). Using the standard protocol in the dynamic phantom, the image quality and visibility of stenoses decreased with an increasing heart rate (p<0.0002 and p<0.004). This was able to be compensated by analysis in an appropriate RR-interval. At the optimal RR-interval, an assessment of the grade of stenoses >30% was feasible up to 120 bpm. Conclusion: Multi-detector computed tomography ultra-high resolution scans allowed the assessment of a wide range of degrees of in-stent restenoses. In this experimental setup, standard protocols allowed a discrimination of low, moderate and high-grade stenoses even at heart rates above 100 bpm.

Koester, R.; Kaehler, J.; Meinertz, T. [Klinik und Poliklinik fuer Kardiologie und Angiologie, Universitaeres Herzzentrum Hamburg (Germany); Van Stevendaal, U.; Grass, M. [Research Sector Medical Imaging Systems, Philips Research Hamburg (Germany); Yamamura, J.; Adam, G.; Begemann, P.G. [Klinik und Poliklinik fuer Diagnostische und Interventionelle Radiologie, Universitaetsklinikum Hamburg-Eppendorf (Germany)

2008-09-15

235

Determinants for Heart Rate Variability in a Normal Korean Population  

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This study examined the normal ranges and the determinants for various parameters of the short-term heart rate variability (HRV) measurements in a large Korean sample of healthy people. HRV measurements were obtained in 2,748 healthy men and 735 healthy women 18-65 yr of age. The mean total power (TP), low frequency (LF), high frequency (HF), and LF/HF ratio were 1,358.9 ± 1,840.8 ms2, 417.3 ± 807.6 ms2, 254.1 ± 414.1 ms2, and 2.4 ± 20.9 ms2 in the frequency-domain spectral analysis. The ...

2011-01-01

236

Heart rate variability on antihypertensive drugs in black patients living in sub-Saharan Africa  

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Background Compared with Caucasians, African Americans have lower heart rate variability (HRV) in the high-frequency domain, but there are no studies in blacks born and living in Africa. Methods In the Newer versus Older Antihypertensive agents in African Hypertensive patients trial (NCT01030458), patients (30–69 years) with uncomplicated hypertension (140–179/90–109 mmHg) were randomized to single-pill combinations of bisoprolol/hydrochlorothiazide (R) or amlodipine/valsartan (E). 72 R and 84 E patients underwent 5-min ECG recordings at randomization and 8, 16 and 24 weeks. HRV was determined by fast Fourier transform and autoregressive modelling. Results Heart rate decreased by 9.5 beats/min in R patients with no change in E patients (? 2.2 beats/min). R patients had reduced total (? 0.13 ms²; p = 0.0038) and low-frequency power (? 3.6 nu; p = 0.057), higher high-frequency (+ 3.3 nu; p = 0.050) and a reduced low- to high-frequency ratio (? 0.08; p = 0.040). With adjustment for heart rate, these differences disappeared, except for the reduced low-frequency power in the R group (? 4.67 nu; p = 0.02). Analyses confined to 39 R and 47 E patients with HRV measurements at all visits or based on autoregressive modelling were confirmatory. Conclusion In native black African patients, antihypertensive drugs modulate HRV, an index of autonomous nervous tone. However, these effects were mediated by changes in heart rate except for low-frequency variability, which was reduced on beta blockade independent of heart rate.

Osakwe, Chukwunomso E.; Jacobs, Lotte; Anisiuba, Benedict C.; Ndiaye, Mouhamado B.; Lemogoum, Daniel; Ijoma, Chinwuba K.; Kamdem, Marius M.; Thijs, Lutgarde; Boombhi, Hilaire J.; Kaptue, Joseph; Kolo, Philip M.; Mipinda, Jean B.; Odili, Augustine N.; Ezeala-Adikaibe, Birinus; Kingue, Samuel; Omotoso, Babatunde A.; Ba, Serigne A.; Ulasi, Ifeoma I.; M'buyamba-Kabangu, Jean-Rene

2014-01-01

237

Regulation of ?-adrenergic control of heart rate by GTP-cyclohydrolase 1 (GCH1) and tetrahydrobiopterin  

Science.gov (United States)

Aims Clinical markers of cardiac autonomic function, such as heart rate and response to exercise, are important predictors of cardiovascular risk. Tetrahydrobiopterin (BH4) is a required cofactor for enzymes with roles in cardiac autonomic function, including tyrosine hydroxylase and nitric oxide synthase. Synthesis of BH4 is regulated by GTP cyclohydrolase I (GTPCH), encoded by GCH1. Recent clinical studies report associations between GCH1 variants and increased heart rate, but the mechanistic importance of GCH1 and BH4 in autonomic function remains unclear. We investigate the effect of BH4 deficiency on the autonomic regulation of heart rate in the hph-1 mouse model of BH4 deficiency. Methods and results In the hph-1 mouse, reduced cardiac GCH1 expression, GTPCH enzymatic activity, and BH4 were associated with increased resting heart rate; blood pressure was not different. Exercise training decreased resting heart rate, but hph-1 mice retained a relative tachycardia. Vagal nerve stimulation in vitro induced bradycardia equally in hph-1 and wild-type mice both before and after exercise training. Direct atrial responses to carbamylcholine were equal. In contrast, propranolol treatment normalized the resting tachycardia in vivo. Stellate ganglion stimulation and isoproterenol but not forskolin application in vitro induced a greater tachycardic response in hph-1 mice. ?1-adrenoceptor protein was increased as was the cAMP response to isoproterenol stimulation. Conclusion Reduced GCH1 expression and BH4 deficiency cause tachycardia through enhanced ?-adrenergic sensitivity, with no effect on vagal function. GCH1 expression and BH4 are novel determinants of cardiac autonomic regulation that may have important roles in cardiovascular pathophysiology.

Adlam, David; Herring, Neil; Douglas, Gillian; De Bono, Joseph P.; Li, Dan; Danson, Edward J.; Tatham, Amy; Lu, Cheih-Ju; Jennings, Katie A.; Cragg, Stephanie J.; Casadei, Barbara; Paterson, David J.; Channon, Keith M.

2012-01-01

238

Blue 405 nm laser light mediates heart rate – investigations at the acupoint Neiguan (Pe.6 in Chinese adults  

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Full Text Available Background: In previous studies, we showed that laser needle acupuncture with red and infrared light has specific effects on bio-signals of the brain and heart. Aims: In this publication we report the effect of blue laser light on heart rate and heart rate variability (HRV before, during and after acupuncture at the acupoint Neiguan (Pe.6 in Chinese adults. These are the first data published concerning heart rate and HRV, obtained with blue laser acupuncture equipment. Patients and Methods: The investigations were carried out in 13 healthy Chinese volunteers with a mean age of 31.2 ± 7.5 years within a randomized, controlled study. Stimulation was performed with painless blue laser light (wavelength: 405 nm; activation: 10 minutes bilaterally at Pe.6. In a second session, for control reasons the laser was not activated. Results Heart rate showed a significant (p=0.008 decrease during blue laser light stimulation. In contrast, no significant changes were found when the laser was deactivated. The evaluation parameter LF/HF ratio (low frequency/high frequency ratio from the HRV spectral analysis showed a very slight increase during stimulation, however it was not significant. Conclusions: Our main conclusion is that continuous blue laser light stimulation on Neiguan significantly reduces heart rate of Chinese adults.

Gerhard Litscher

2009-10-01

239

Heart rate and respiratory rhythm dynamics on ascent to high altitude.  

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OBJECTIVE--To investigate the alterations in autonomic control of heart rate at high altitude and to test the hypothesis that hypoxaemic stress during exposure to high altitude induces non-linear, periodic heart rate oscillations, similar to those seen in heart failure and the sleep apnoea syndrome. SUBJECTS--11 healthy subjects aged 24-64. MAIN OUTCOME MEASURES--24 hour ambulatory electrocardiogram records obtained at baseline (1524 m) and at 4700 m. Simultaneous heart rate and respiratory d...

Lipsitz, L. A.; Hashimoto, F.; Lubowsky, L. P.; Mietus, J.; Moody, G. B.; Appenzeller, O.; Goldberger, A. L.

1995-01-01

240

Human heart rate variability relation is unchanged during motion sickness  

Science.gov (United States)

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.

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

1998-01-01

 
 
 
 
241

Importance of heart rate analysis in exercise tolerance test  

Directory of Open Access Journals (Sweden)

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.

Artur Haddad Herdy

2003-08-01

242

Importance of heart rate analysis in exercise tolerance test  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english 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.

Herdy, Artur Haddad; Fay, Carlos Eduardo Schio; Bornschein, Christian; Stein, Ricardo.

243

Double blind placebo controlled trial of short term transdermal scopolamine on heart rate variability in patients with chronic heart failure.  

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OBJECTIVE: To test the hypothesis that short term application of transdermal scopolamine increases heart rate variability (HRV) and restores sympathovagal balance in patients with stable congestive heart failure (CHF). DESIGN: A double blind placebo controlled crossover study. SETTING: Tertiary referral centre. PATIENTS: Twelve patients (mean age 66 (10)) with New York Heart Association class II-IV CHF. All patients had coronary artery disease (mean left ventricular ejection fraction 26.7 (8....

Venkatesh, G.; Fallen, E. L.; Kamath, M. V.; Connolly, S.; Yusuf, S.

1996-01-01

244

Heart rates increase after hatching in two species of Natricine snakes.  

Science.gov (United States)

Experimental studies have shown heart rates to decrease from embryo to hatchling stage in turtles, remain steady in skinks, and increase in birds. However, no snake species has been studied in this regard. I recorded heart rate evolution trajectories from embryo to juvenile stage in 78 eggs from two species of European Natricine snakes. Unexpectedly, snakes behaved more like birds than turtles or lizards: heart rates increased after hatching in both N. maura and N. natrix, respectively by 43.92 ± 22.84% and 35.92 ± 24.52%. Heart rate shift was not related to an abrupt elevation of metabolism per se (snakes that increased their heart rates the most sharply grew the least after birth), but rather due to a number of smaller eggs that experienced lower than normal heart rates throughout the incubation and recovered a normal heart rate post-birth. This finding is discussed in the light of hatching synchrony benefits. PMID:24287712

Aubret, Fabien

2013-01-01

245

Contact-free heart rate measurement using multiple video data  

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In this paper, we propose a contact-free heart rate measurement method by analyzing sequential images of multiple video data. In the proposed method, skin-like pixels are firstly detected from multiple video data for extracting the color features. These color features are synchronized and analyzed by independent component analysis. A representative component is finally selected among these independent component candidates to measure the HR, which achieves under 2% deviation on average compared with a pulse oximeter in the controllable environment. The advantages of the proposed method include: 1) it uses low cost and high accessibility camera device; 2) it eases users' discomfort by utilizing contact-free measurement; and 3) it achieves the low error rate and the high stability by integrating multiple video data.

Hung, Pang-Chan; Lee, Kual-Zheng; Tsai, Luo-Wei

2013-10-01

246

Heart rate recovery and heart rate variability are unchanged in patients with coronary artery disease following 12 weeks of high-intensity interval and moderate-intensity endurance exercise training.  

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Decreased heart rate variability and attenuated heart rate recovery following exercise are associated with an increased risk of mortality in cardiac patients. This study investigated the effects of 12 weeks of moderate-intensity endurance exercise (END) and a novel low-volume high-intensity interval exercise protocol (HIT) on measures of heart rate recovery and heart rate variability in patients with coronary artery disease (CAD). Fourteen males with CAD participated in 12 weeks of END or HIT training, each consisting of 2 supervised exercise sessions per week. END consisted of 30-50 min of continuous cycling at 60% peak power output (PPO). HIT involved ten 1-min intervals at 88% PPO separated by 1-min intervals at 10% PPO. Heart rate recovery at 1 min and 2 min was measured before and after training (pre- and post-training, respectively) using a submaximal exercise bout. Resting time and spectral and nonlinear domain measures of heart rate variability were calculated. Following 12 weeks of END and HIT, there was no change in heart rate recovery at 1 min (END, 40 ± 12 beats·min(-1) vs. 37 ± 19 beats·min(-1); HIT, 31 ± 8 beats·min(-1) vs. 35 ± 8 beats·min(-1); p ? 0.05 for pre- vs. post-training) or 2 min (END, 44 ± 18 beats·min(-1) vs. 43 ± 19 beats·min(-1); HIT, 42 ± 10 beats·min(-1) vs. 50 ± 6 beats·min(-1); p ? 0.05 for pre- vs. post-training). All heart rate variability indices were unchanged following END and HIT training. In conclusion, neither END nor HIT exercise programs elicited training-induced improvements in cardiac autonomic function in patients with CAD. The absence of improvements with training may be attributed to the optimal medical management and normative pretraining state of our sample. PMID:23724882

Currie, Katharine D; Rosen, Lee M; Millar, Philip J; McKelvie, Robert S; Macdonald, Maureen J

2013-06-01

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The slope of the oxygen pulse curve does not depend on the maximal heart rate in elite soccer players  

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INTRODUCTION: It is unknown whether an extremely high heart rate can affect oxygen pulse profile during progressive maximal exercise in healthy subjects. OBJECTIVE: Our aim was to compare relative oxygen pulse (adjusted for body weight) curves in athletes at their maximal heart rate during treadmill cardiopulmonary exercise testing. METHODS: A total of 180 elite soccer players were categorized in quartiles according to their maximum heart rate values (n ?=? 45). Oxygen consumption, maximum heart rate and relative oxygen pulse curves in the extreme quartiles, Q1 and Q4, were compared at intervals corresponding to 10% of the total duration of a cardiopulmonary exercise testing. RESULTS: Oxygen consumption was similar among all subjects during cardiopulmonary exercise testing; however subjects in Q1 started to exhibit lower maximum heart rate values when 20% of the test was complete. Conversely, the relative oxygen pulse was higher in this group when cardiopulmonary exercise testing was 40% complete (p<.01). Although the slopes of the lines were similar (p?=?.25), the regression intercepts differed (p<.01) between Q1 and Q4. During the last two minutes of testing, a flat or decreasing oxygen pulse was identified in 20% of the soccer players, and this trend was similar between subjects in Q1 and Q4. CONCLUSION: Relative oxygen pulse curve slopes, which serve as an indirect and non-invasive surrogate for stroke volume, suggest that the stroke volume is similar in young and aerobically fit subjects regardless of the maximum heart rate reached.

Perim, Raphael Rodrigues; Signorelli, Gabriel Ruiz; Myers, Jonathan; Arena, Ross; de Araujo, Claudio Gil Soares

2011-01-01

248

The slope of the oxygen pulse curve does not depend on the maximal heart rate in elite soccer players  

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Full Text Available INTRODUCTION: It is unknown whether an extremely high heart rate can affect oxygen pulse profile during progressive maximal exercise in healthy subjects. OBJECTIVE: Our aim was to compare relative oxygen pulse (adjusted for body weight curves in athletes at their maximal heart rate during treadmill cardiopulmonary exercise testing. METHODS: A total of 180 elite soccer players were categorized in quartiles according to their maximum heart rate values (n = 45. Oxygen consumption, maximum heart rate and relative oxygen pulse curves in the extreme quartiles, Q1 and Q4, were compared at intervals corresponding to 10% of the total duration of a cardiopulmonary exercise testing. RESULTS: Oxygen consumption was similar among all subjects during cardiopulmonary exercise testing; however subjects in Q1 started to exhibit lower maximum heart rate values when 20% of the test was complete. Conversely, the relative oxygen pulse was higher in this group when cardiopulmonary exercise testing was 40% complete (p<.01. Although the slopes of the lines were similar (p = .25, the regression intercepts differed (p<.01 between Q1 and Q4. During the last two minutes of testing, a flat or decreasing oxygen pulse was identified in 20% of the soccer players, and this trend was similar between subjects in Q1 and Q4. CONCLUSION: Relative oxygen pulse curve slopes, which serve as an indirect and non-invasive surrogate for stroke volume, suggest that the stroke volume is similar in young and aerobically fit subjects regardless of the maximum heart rate reached.

Raphael Rodrigues Perim

2011-01-01

249

Heart rate response to hypoxic exercise : role of dopamine D2-receptors and effect of oxygen supplementation  

DEFF Research Database (Denmark)

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 two consecutive maximal exercise tests, without and with oxygen supplementation respectively, at sea level and after 1, 3 and 5 days at altitude. On each study day, domperidone (30 mg; n=6) or no medication (n=6) was given 1 h before the first exercise session. Compared with sea level, hypoxia 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 of noradrenaline. However, dopamine D(2)-receptors are not involved in the hypoxia-induced decrease in the maximal heart rate. These data suggest that receptor uncoupling, and not down-regulation, of cardiac adrenoreceptors, is responsible for the early decrease in heart rate at maximal hypoxic exercise.

Lundby, C; Møller, P

2001-01-01

250

Role of GABAA receptors of bed nucleus stria terminalis in controlling of blood pressure and heart rate in rats  

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Full Text Available Introduction: The Bed nucleus stria terminalis (BST is a part of the limbic system. It was recently shown that chemical stimulation of the BST by L-glutamate elicited cardiovascular depressive responses. In the present study, we have investigated the possible cardiovascular role of the GABAergic receptors in BST by microinjection of its agonist and antagonists. Methods: Experiments were performed on 21 anaesthetized rats. Drugs were microinjected into the BST in volume of 50 nl using streotaxic apparatus. Blood pressure and heart rate were recorded before and throughout each experiment. The averages of maximum changes in the arterial pressure and heart rate were compared with control group and with its average in before injections using student t-test and paired t-test, respectively. Results: GABAA receptor antagonist, bicuculline met iodide (BMI, 1 mM, increased both arterial pressure (+14.2±3.08 and heart rate (+9.8± 2.5 (p<0.05. Muscimole, a GABAA agonist (5 mM, caused a significant decrease of the arterial pressure (-10.2 ±4.1 and heart rate (-20.3±9.40 (p<0.01. However, microinjection of phaclofen (5 mM, a GABAB receptor antagonist caused small unsignificant changes of the heart rate and blood pressure. Conclusion: GABAergic inhibitory neurons of the BST seems to cause decrease in the blood pressure and heart rate by GABAA but not GABAB receptors.

Maesoumeh Hatam

2007-03-01

251

Heart rate variability in risk stratification of cardiac patients.  

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Heart rate (HR) variability has been extensively studied in cardiac patients, especially in patients surviving an acute myocardial infarction (AMI) and also in patients with congestive heart failure (CHF) or left ventricular (LV) dysfunction. The majority of studies have shown that patients with reduced or abnormal HR variability have an increased risk of mortality within a few years after an AMI or after a diagnosis of CHF/LV dysfunction. Various measures of HR dynamics, such as time-domain, spectral, and non-linear measures of HR variability have been used in risk stratification. The prognostic power of various measures, except of those reflecting rapid R-R interval oscillations, has been almost identical, albeit some non-linear HR variability measures, such as short-term fractal scaling exponent have provided somewhat better prognostic information than the others. Abnormal HR variability predicts both sudden and non-sudden cardiac death. Because of remodeling of the arrhythmia substrate after AMI, early measurement of HR variability to identify those at high risk should likely be repeated later in order to assess the risk of fatal arrhythmia events. Future randomized trials using HR variability/turbulence as one of the pre-defined inclusion criteria will show whether routine measurement of HR variability/turbulence will become a routine clinical tool for risk stratification of cardiac patients. PMID:24215747

Huikuri, Heikki V; Stein, Phyllis K

2013-01-01

252

Evaluation of an Exercise Field Test Using Heart Rate Monitors to Assess Cardiorespiratory Fitness and Heart Rate Recovery in an Asymptomatic Population  

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Purpose Measures of cardiorespiratory fitness (CRF) and heart rate recovery (HRR) can improve risk stratification for cardiovascular disease, but these measurements are rarely made in asymptomatic individuals due to cost. An exercise field test (EFT) to assess CRF and HRR would be an inexpensive method for cardiovascular disease risk assessment in large populations. This study assessed 1) the predictive accuracy of a 12-minute run/walk EFT for estimating CRF () and 2) the accuracy of HRR measured after an EFT using a heart rate monitor (HRM) in an asymptomatic population. Methods Fifty subjects (48% women) ages 18–45 years completed a symptom-limited exercise tolerance test (ETT) (Bruce protocol) and an EFT on separate days. During the ETT, was measured by a metabolic cart, and heart rate was measured continuously by a HRM and a metabolic cart. Results EFT distance and sex independently predicted. The average absolute difference between observed and predicted was 0.26±3.27 ml·kg?1·min?1 for our model compared to 7.55±3.64 ml·kg?1·min?1 for the Cooper model. HRM HRR data were equivalent to respective metabolic cart values during the ETT. HRR at 1 minute post-exercise during ETT compared to the EFT had a moderate correlation (r?=?0.75, p<0.001). Conclusion A more accurate model to estimate CRF from a 12-minute run/walk EFT was developed, and HRR can be measured using a HRM in an asymptomatic population outside of clinical settings.

Coolbaugh, Crystal L.; Anderson, Ivan B.; Wilson, Machelle D.; Hawkins, David A.; Amsterdam, Ezra A.

2014-01-01

253

Heart rate monitoring on the stroke unit. What does heart beat tell about prognosis? An observational study  

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Full Text Available Abstract Background Guidelines recommend maintaining the heart rate (HR of acute stroke patients within physiological limits; data on the frequency and predictors of significant deviations from these limits are scarce. Methods Demographical data, stroke risk factors, NIH stroke scale score, lesion size and location, and ECG parameters were prospectively assessed in 256 patients with ischemic stroke. Patients were continuously monitored for at least 24 hours on a certified stroke unit. Tachycardia (HR ?120 bpm and bradycardia (HR Results HR ?120 bpm occurred in 39 patients (15%. Stroke severity (larger lesion size/higher NIHSS-score on admission, atrial fibrillation and HR on admission predicted its occurrence. HR Conclusions Significant tachycardia and bradycardia are frequent phenomena in acute stroke; however they do not independently predict clinical course or outcome. Continuous monitoring allows detecting rhythm disturbances in stroke patients and allows deciding whether urgent medical treatment is necessary.

Stypmann Jörg

2011-04-01

254

Heart Rate Variability Analysis Using Threshold of Wavelet Package Coefficients  

CERN Document Server

In this paper, a new efficient feature extraction method based on the adaptive threshold of wavelet package coefficients is presented. This paper especially deals with the assessment of autonomic nervous system using the background variation of the signal Heart Rate Variability HRV extracted from the wavelet package coefficients. The application of a wavelet package transform allows us to obtain a time-frequency representation of the signal, which provides better insight in the frequency distribution of the signal with time. A 6 level decomposition of HRV was achieved with db4 as mother wavelet, and the above two bands LF and HF were combined in 12 specialized frequencies sub-bands obtained in wavelet package transform. Features extracted from these coefficients can efficiently represent the characteristics of the original signal. ANOVA statistical test is used for the evaluation of proposed algorithm.

Kheder, G; Massoued, M Ben; Samet, M

2009-01-01

255

Spectral and Time Based Assessment of Meditative Heart Rate Signals  

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Full Text Available The objective of this article was to study the effects of Chi meditation on heart rate variability (HRV. For this purpose, the statistical and spectral measures of HRV from the RR intervals were analyzed. In addition, it is concerned with finding adequate Auto-Regressive Moving Average (ARMA model orders for spectral analysis of the time series formed from RR intervals. Therefore, Akaike’s Final Prediction Error (FPE was taken as the base for choosing the model order. The results showed that overall the model order chosen most frequently for FPE was p = 8 for before meditation and p = 5 for during meditation. The results suggested that variety of orders in HRV models upon different psychological states could be due to some differences in intrinsic properties of the system.

Ateke Goshvarpour

2013-04-01

256

Neuro-Fuzzy Approach to Heart Rate Variability Analysis  

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Full Text Available Heart rate variability (HRV analysis attempts to assess cardiac autonomic regulation through quantification of sinus rhythm variability. The sinus rhythm times series is derived from the QRS to QRS (RR interval sequence of the electrocardiogram (ECG, by extracting only normal sinus to normal sinus (NN interbeat intervals. Relatively high frequency variations in sinus rhythm reflect parasympathetic (vagal modulation, and slower variations reflect a combination of both parasympathetic and sympathetic modulation and non-autonomic factors. The paper focuses on the Neuro-fuzzy system. It is used to recognize the HRV signals for diagnosis by extract the QRST zone of ECG signals using Discrete Cosine Transform (DCT. The result is exciting as much as we have used only one of ECG lead to records input data, while the current diagnosis approaches require the set of 12 lead ECG signals!

Hoang ChuDuc

2013-09-01

257

Should the augmentation index be normalized to heart rate?  

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Pulse wave analysis(PWA) is widely used to investigate systemic arterial stiffness. The augmentation index(AIx), the primary outcome derived from PWA, is influenced by the mean arterial pressure(MAP), age, gender and heart rate(HR). Gender- and age-specific reference values have been devised, and it is recommended that the MAP be used as a statistical covariate. The AIx is also commonly statistically adjusted to a HR of 75 b·min(-1); however, this approach may be physiologically and statistically inappropriate. First, there appears to be an important physiological chronic interaction between HR and arterial stiffness. Second, the method used to correct to HR assumes that the relationship with AIx is uniform across populations. A more appropriate practice may be to include HR as an independent predictor or covariate; this approach is particularly recommended for longitudinal studies, in which changes in HR may help to explain changes in arterial stiffness. PMID:24257465

Stoner, Lee; Faulkner, James; Lowe, Andrew; M Lambrick, Danielle; M Young, Joanna; Love, Richard; S Rowlands, David

2014-01-23

258

Automated Fetal Heart Rate Analysis in Labor: Decelerations and Overshoots  

International Nuclear Information System (INIS)

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 deg.) and 'modified' Positive Predictive Value (PPV deg.) 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.

2010-10-25

259

Association between Heart Rate Variability, Blood Pressure and Autonomic Activity in Cyclic Alternating Pattern during Sleep  

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Study Objectives: Cyclic alternating pattern (CAP) is frequently followed by changes in heart rate (HR) and blood pressure (BP), but the sequential associations between CAP and autonomic nerve activity have not been studied. The study aimed to reveal the precise changes in heart rate variability (HRV) during phase A of the CAP cycle. Design: Polysomnography was recorded according to the CAP Atlas (Terzano, 2002), and BP and electrocardiogram were simultaneously recorded. The complex demodulation method was used for analysis of HRV and evaluation of autonomic nerve activity. Setting: Academic sleep laboratory. Participants: Ten healthy males. Measurements and Results: The increase in HR (median [first quartile – third quartile]) for each subtype was as follows: A1, 0.64 (-0.30 to 1.69), A2, 1.44 (0.02 to 3.79), and A3, 6.24 (2.53 to 10.76) bpm (A1 vs. A2 P < 0.001, A1 vs. A3 P < 0.001, A2 vs. A3 P < 0.001). The increase in BP for each subtype was as follows: A1, 1.23 (-2.04 to 5.75), A2, 1.76 (-1.46 to 9.32), and A3, 12.51 (4.75 to 19.94) mm Hg (A1 vs. A2 P = 0.249, A1 vs. A3 P < 0.001, A2 vs. A3 P < 0.001). In all of phase A, the peak values for HR and BP appeared at 4.2 (3.5 to 5.4) and 8.4 (7.0 to 10.3) seconds, respectively, after the onset of phase A. The area under the curve for low-frequency and high-frequency amplitude significantly increased after the onset of CAP phase A (P < 0.001) and was higher in the order of subtype A3, A2, and A1 (P < 0.001). Conclusions: All phase A subtypes were accompanied with increased heart rate variability, and the largest heart rate variability was seen in subtype A3, while a tendency for less heart rate variability was seen in subtype A1. Citation: Kondo H; Ozone M; Ohki N; Sagawa Y; Yamamichi K; Fukuju M; Yoshida T; Nishi C; Kawasaki; Mori; Kanbayashi T; Izumi M; Hishikawa Y; Nishino S; Shimizu T. Association between heart rate variability, blood pressure and autonomic activity in cyclic alternating pattern during sleep. SLEEP 2014;37(1):187-194.

Kondo, Hideaki; Ozone, Motohiro; Ohki, Noboru; Sagawa, Yohei; Yamamichi, Keiichirou; Fukuju, Mitsuki; Yoshida, Takeshi; Nishi, Chikako; Kawasaki, Akiko; Mori, Kaori; Kanbayashi, Takashi; Izumi, Motomori; Hishikawa, Yasuo; Nishino, Seiji; Shimizu, Tetsuo

2014-01-01

260

Limitations of oximetry to measure heart rate variability measures.  

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Measuring heart rate variability (HRV) is widely used to assess autonomic nervous system function. It requires accurate measurement of the interval between successive heartbeats. This can be achieved from recording the electrocardiogram (ECG), which is non-invasive and widely available. However, methodological problems inherent in recording and analyzing ECG traces have motivated a search for alternative means of measuring the interval between successive heartbeats. Recording blood oxygenation pulsations (photoplethysmography-PPG) is also convenient, non-invasive and widely available, and has been suggested as an effective alternative to ECG to derive HRV. Moreover, it has been claimed that the pulse waveforms produced by oximetry may be more practicable than R-R intervals measured from the by ECG, especially for ambulatory recordings. We have therefore compared PPG with ECG recordings to measure HRV applying the same signal analysis techniques to PPG and ECG recordings made simultaneously. Comparison of 5 min recording epochs demonstrated a very high degree of correlation, in temporal, frequency domains and non-linear analysis, between HRV measures derived from the PPG and ECG. However, we found that the PPG signal is especially vulnerable to motion artifacts when compared to the ECG, preventing any HRV analysis at all in a significant minority of PPG recordings. Our results demonstrate that even though PPG provides accurate interpulse intervals to measure heart rate variability under ideal conditions, it is less reliable due to its vulnerability to motion artifacts. Therefore it is unlikely to prove a practical alternative to the ECG in ambulatory recordings or recordings made during other activities. PMID:19728090

Lu, Guohua; Yang, Fang

2009-09-01

 
 
 
 
261

HEART RATE AND BLOOD LACTATE RESPONSES TO CHANGQUAN AND DAOSHU FORMS OF MODERN WUSHU  

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Full Text Available The development of specific training designed to enhance physiological aspects of performance relies heavily on the availability of accurate and validity physiological data. In the combat sport of Wushu, katas are used to develop aerobic fitness. It is arguably important to assess and monitor heart rate (HR and lactate (La responses when designing effective training programs. The aim of this pilot study was to investigate heart rate and lactate responses to forms execution among Wushu combatants. Male elite modern Wushu athletes (n = 4 from a South Brazilian regional team participated in the study. Athletes were aged 22.5 ± 2.08 years old and had at least eight years of Wushu experience. Athletes carried out the Changquan and Daoshu forms in random order, HR and La were measured pre- and post-exercise. Results indicate that HR was 176 ± 3 and 176 ± 2 bpm and La was 4.38 ± 1.3 and 5.15 ± 1.07 mmol·l-1 for Changquan and Daoshu forms, respectively. There were no significantly differences in HR and La between the two forms. HR values represent 89.2 ± 1.1 and 89.1 ± 1.8% of age-predicted maximal heart rate and lactate was near of 4 mmol·l-1 point. In conclusion, training programs to Wushu combatants could target the range of physiological values cited above with no differences between two forms

Jerri Luiz Ribeiro

2006-07-01

262

Comparison of heart rate variability and pulse rate variability detected with photoplethysmography  

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This study compares ear photoplethysmography (PPG) and electrocardiogram (ECG) in providing accurate heart beat intervals for use in calculations of heart rate variability (HRV, from ECG) or of pulse rate variability (PRV, from PPG) respectively. Simultaneous measurements were taken from 44 healthy subjects at rest during spontaneous breathing and during forced metronomic breathing (6/min). Under both conditions, highly significant (p > 0.001) correlations (1.0 > r > 0.97) were found between all evaluated common HRV and PRV parameters. However, under both conditions the PRV parameters were higher than HRV. In addition, we calculated the limits of agreement according to Bland and Altman between both techniques and found good agreement ( 20%) agreement for other standard HRV and PRV parameters. Thus, PRV data seem to be acceptable for screening purposes but, at least at this state of knowledge, not for medical decision making. However, further studies are needed before more certain determination can be made.

Rauh, Robert; Limley, Robert; Bauer, Rainer-Dieter; Radespiel-Troger, Martin; Mueck-Weymann, Michael

2004-08-01

263

Statins, ventricular arrhythmias and heart rate variability in patients with implantable cardioverter defibrillators and coronary heart disease  

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The aim of this study was to evaluate whether the incidence of ventricular arrhythmias and heart rate variability were influenced by statin treatment and lipid levels in patients treated with an implantable cardioverter defibrillator (ICD). Heart rate variability measurements were performed in 86 patients with coronary heart disease and an ICD implant. The number of events with ventricular fibrillation and ventricular tachycardia were recorded during a 12-month period. This study lends little support for an antiarrhythmic effect of statins or any relation between plasma lipids and lipoproteins and malignant ventricular arrhythmias in patients with an ICD.

Riahi, Sam; Schmidt, Erik Berg

2005-01-01

264

Dynamics of the heart rate variability in patients with atrial fibrillation during atorvastatin therapy  

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Full Text Available Aim. To evaluate the heart rate variability (HRV in patients with ischemic heart disease (IHD and paroxysmal atrial fibrillation (AF during atorvastatin therapy.Material and methods. 60 patients with IHD and paroxysmal AF were included in the study. Patients were divided into two groups – control group (basic antiarrhythmic therapy and second group (basic antiarrhythmic therapy and atorvastatin (Liptonorm, Pharmstandart, Russia 10mg/day. HRV was compared before and after 3 months of therapy in both groups.Results. Liptonorm significantly improved HRV indices in comparison with basic therapy alone: RMSSD increased on 33% (?<0,02, total power (TP of spectrum on 28% (?<0,03 and high frequency (HF component on 53 % (?<0,01.Conclusion. Liptonorm therapy improves autonomic balance in patients with IHD and paroxysmal AF.

E.S. Kozlova

2008-01-01

265

Initial heart rate and cardiovascular outcomes in patients presenting with acute coronary syndrome.  

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Abstract Objectives: To assess the impact of on-admission heart rate (HR) in patients presenting with acute coronary syndrome (ACS). Methods: Data were collected retrospectively from the second Gulf Registry of Acute Coronary Events. Patients were divided according to their initial HR into: (I: HR. Groups I and V were associated with worse hospital outcomes. Multivariate analysis showed initial tachycardia as an independent predictor for heart failure (OR 2.2; 95%CI: 1.39-3.32), while bradycardia was independently associated with higher one-month mortality (OR 2.0; 95%CI: 1.04-3.85) Conclusion: The majority of ACS patients present with tachycardia. However, low or high HR is a marker of high risk that needs more attention and management. PMID:24702593

Asaad, Nidal; El-Menyar, Ayman; Alhabib, Khalid F; Shabana, Adel; Alsheikh-Ali, Alawi A; Almahmeed, Wael; Al Faleh, Hussam; Hersi, Ahmad; Al Saif, Shukri; Al-Motarreb, Ahmed; Sulaiman, Kadhim; Al Nemer, Khalid; Amin, Haitham; Al Suwaidi, Jassim

2014-06-01

266

Effect of bronchodilators on heart rate variability in patients with chronic obstructive pulmonary disease  

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Full Text Available Aim. To study effect of long-acting theophylline (Theotard, KRKA and combination of salmeterol and fluticasone (Seretide, GlaxoSmithKline on heart rhythm variability (HRV and number of arrhythmic episodes in patients with chronic obstructive pulmonary disease (COPD.Material and methods. 144 patients with COPD and 35 patients of control group were examined. The analysis of HRV and Holter monitoring were made f on 2th and 14th days. Results. Treatment with both drugs led to increase in power of low- and high frequencies and their ratio (LF/HF, decrease in rate of supraventricular and ventricular arrhythmias. Theophylline therapy raised in a number of single and pair supraventricular extrasystoles. Treatment with combination of salmeterol and fluticasone did not change a number of extrasystoles.Conclusion. Combination of salmeterol and fluticasone is more preferable as a broncholytic therapy for patients with COPD and heart rhythm disorders.

H.H. Shugushev

2007-01-01

267

Heart Rate Variability in Cavalier King Charles Spaniels with Different Degree of Myxomatous Mitral Valve Disease  

DEFF Research Database (Denmark)

Heart Rate Variability in Cavalier King Charles Spaniels with Different Degree of Myxomatous Mitral Valve Disease Rasmussen, C.E. 1, Falk, T. 1, Zois, N.E. 1, Moesgaard, S.G. 1, Häggström, J. 2, Pedersen, H.D. 3 and Olsen, L.H1. 1Department of Basic Animal and Veterinary Sciences, Faculty of Life Sciences, University of Copenhagen, Frederiksberg, Denmark, 2Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden; and 3Novo Nordic A/S, Maaloev, Denmark. Introduction: Modulation of heart rate by the autonomic nervous system can indirectly be measured by heart rate variability (HRV). Reduced HRV is seen in dogs with heart failure secondary to myxomatous mitral valve disease (MMVD). However, HRV is suggested to increase with disease progression in dogs with early stages of MMVD. Comparable results are found in people with primary mitral valve prolapse, a disease resembling canine MMVD. Aim: To associate progression of MMVD in dogs with time and frequency domain HRV, analysed from 24-hour electrocardiography. Materials and Methods: Eighty-one Cavalier King Charles Spaniels (CKCS) were examined by echocardiography and 24-hour electrocardiography. CKCS were divided into 4 groups: 1) no or minimal mitral regurgitation (MR) (MR jet=15% of the left atrial area) and no murmur, 2) mild MR (20%50%) and no clinical signs of heart failure, 4) left atrium to aortic root ratio >1.5, clinical signs of heart failure and furosemide responsiveness. Results: Ten out of 13 HRV variables decreased with increasing MMVD severity. In group 1, 10 HRV variables were increased compared to group 3 and 4 (P<0.05) and 2 HRV variables were increased compared to group 2 (P<0.04). Eight and 10 HRV variables were increased in group 2 compared to group 3 (P<0.01) and group 4 (P<0.001), respectively. Group 1 and 2 were younger than group 3 and 4 (P<0.0001). Only 2 HRV variables were influenced by age. Discussion and conclusion: Most HRV variables decreased with progression of MMVD in dogs; even prior to the development of overt congestive heart failure.

Rasmussen, Caroline Elisabeth; Falk, Bo Torkel

268

Effects of umbilical venous catheters on arrhythmia and heart rate variability in premature newborns  

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Full Text Available Aim: Cardiac rhythm abnormalities associated with umbilical venous catheters in newborns are limited to anecdotal case reports. The present study intended to evaluate association between umbilical venous catheter, arrhythmic potential, and changes in heart rate variability.Material and Method: The study consisted of two groups; 26 preterm newborns with a umbilical venous catheter (group 1, and 26 control group without (group 2. The following parameters were recorded prospectively: gender, gestation at birth, birth weight, and clinical assessment scores (SNAP-II and SNAPPE-II. Holter recordings were fitted in all newborns. The heart rate variability study was performed by utilizing time-domain and frequency-domain analyses. Results: The study population consisted of group 1 (30.63±2.67 weeks of gestation and group 2 (31.60±2.45 weeks of gestation. There was no statistical difference between the two groups for gestational age, birth weight, SNAP-II and SNAPPE- II scores. When compared for arrhythmia there was no statistical difference in any parameters between the two study groups. Premature atrial contraction was noted in 11 babies (42.3% in group 1 and in 7 babies (26.9% in group 2. Premature ventricular contraction was noted in 3 babies (11.5% in group 1 and in one baby in group 2. Sinus tachycardia detected in 3 patients in only the group 1. None of the heart rate variability parameters were found to be statistically different between the two groups.Conclusions: Our study reassuringly demonstrated that umbilical venous catheter does not have any significant effect on arrhythmia or heart rate variability in preterm newborns. (Turk Arch Ped 2013; 48: 131-7

Kadir Babao?lu

2013-06-01

269

Noninvasive coronary angiography using 64-slice spiral computed tomography in an unselected patient collective: Effect of heart rate, heart rate variability and coronary calcifications on image quality and diagnostic accuracy  

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Objective: The aim of this study was to assess the impact of heart rate, heart rate variability and calcification on image quality and diagnostic accuracy in an unselected patient collective. Subjects and methods: One hundred and two consecutive patients with known or suspected coronary artery disease underwent both 64-MSCT and invasive coronary angiography. Image quality (IQ) was assessed by independent observers using a 4-point scale from excellent (1) to non-diagnostic (4). Accuracy of MSCT regarding detection or exclusion of significant stenosis (>50%) was evaluated on a per segment basis in a modified AHA 13-segment model. Effects of heart rate, heart rate variability, calcification and body mass index (BMI) on IQ and accuracy were evaluated by multivariate regression. IQ and accuracy were further analysed in subgroups of significant predictor variables and simple regression performed to calculate thresholds for adequate IQ. Results: Mean heart rate was 68.2 {+-} 13.3 bpm, mean heart rate variability 11.5 {+-} 16.0 beats per CT-examination (bpct) and median Agatston score 226.5. Average IQ score was 2 {+-} 0.6 whilst diagnostic quality was obtained in 89% of segments. Overall sensitivity, specificity, PPV or NPV was 91.2%, 99.2%, 95.3% or 98.3%. According to multivariate regression, overall IQ was significantly related to heart rate and calcification (P = 0.0038; P < 0.0001). The effect of heart rate variability was limited to IQ of RCA segments (P = 0.018); BMI was not related to IQ (P = 0.52). Calcification was the only predictor variable with significant effect on the number of non-diagnostic segments (P < 0.0001). In a multivariate regression, calcification was also the single factor with impact on diagnostic accuracy (P = 0.0049). Conclusion: Whilst heart rate, heart rate variability and calcification all show an inverse correlation to IQ, severe calcium burden remains the single factor with translation of such effect into decrease of diagnostic accuracy.

Brodoefel, H. [Department of Diagnostic Radiology, Eberhard-Karls-University, Hoppe-Seyler-Str. 3, 72076 Tuebingen (Germany)], E-mail: h.brodoefel@t-online.de; Reimann, A. [Department of Diagnostic Radiology, Eberhard-Karls-University, Hoppe-Seyler-Str. 3, 72076 Tuebingen (Germany); Burgstahler, C. [Department of Cardiology, Eberhard-Karls-University, Otfried-Mueller-Str. 10, 72076 Tuebingen (Germany); Schumacher, F. [Department of Diagnostic Radiology, Eberhard-Karls-University, Hoppe-Seyler-Str. 3, 72076 Tuebingen (Germany); Herberts, T. [Department of Medical Biometry, Westbahnhofstr. 55, 72070 Tuebingen (Germany); Tsiflikas, I. [Department of Diagnostic Radiology, Eberhard-Karls-University, Hoppe-Seyler-Str. 3, 72076 Tuebingen (Germany); Schroeder, S. [Department of Cardiology, Eberhard-Karls-University, Otfried-Mueller-Str. 10, 72076 Tuebingen (Germany); Claussen, C.D.; Kopp, A.F.; Heuschmid, M. [Department of Diagnostic Radiology, Eberhard-Karls-University, Hoppe-Seyler-Str. 3, 72076 Tuebingen (Germany)

2008-04-15

270

Noninvasive coronary angiography using 64-slice spiral computed tomography in an unselected patient collective: Effect of heart rate, heart rate variability and coronary calcifications on image quality and diagnostic accuracy  

International Nuclear Information System (INIS)

Objective: The aim of this study was to assess the impact of heart rate, heart rate variability and calcification on image quality and diagnostic accuracy in an unselected patient collective. Subjects and methods: One hundred and two consecutive patients with known or suspected coronary artery disease underwent both 64-MSCT and invasive coronary angiography. Image quality (IQ) was assessed by independent observers using a 4-point scale from excellent (1) to non-diagnostic (4). Accuracy of MSCT regarding detection or exclusion of significant stenosis (>50%) was evaluated on a per segment basis in a modified AHA 13-segment model. Effects of heart rate, heart rate variability, calcification and body mass index (BMI) on IQ and accuracy were evaluated by multivariate regression. IQ and accuracy were further analysed in subgroups of significant predictor variables and simple regression performed to calculate thresholds for adequate IQ. Results: Mean heart rate was 68.2 ± 13.3 bpm, mean heart rate variability 11.5 ± 16.0 beats per CT-examination (bpct) and median Agatston score 226.5. Average IQ score was 2 ± 0.6 whilst diagnostic quality was obtained in 89% of segments. Overall sensitivity, specificity, PPV or NPV was 91.2%, 99.2%, 95.3% or 98.3%. According to multivariate regression, overall IQ was significantly related to heart rate and calcification (P = 0.0038; P < 0.0001). The effect of heart rate variability was limited to IQ of RCA segments (P = 0.018); BMI was not related to IQ (P = 0.52). Calcification was the only predictor variable with significant effect on the number of non-diagnostic segments (P < 0.0001). In a multivariate regression, calcification was also the single factor with impact on diagnostic accuracy (P = 0.0049). Conclusion: Whilst heart rate, heart rate variability and calcification all show an inverse correlation to IQ, severe calcium burden remains the single factor with translation of such effect into decrease of diagnostic accuracy

2008-04-01

271

Skeletal muscle signaling and the heart rate and blood pressure response to exercise : insight from heart rate pacing during exercise with a trained and a deconditioned muscle group  

DEFF Research Database (Denmark)

Endurance training lowers heart rate and blood pressure responses to exercise, but the mechanisms and consequences remain unclear. To determine the role of skeletal muscle for the cardioventilatory response to exercise, 8 healthy young men were studied before and after 5 weeks of 1-legged knee-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 was Ë?15 bpm lower during exercise with the trained leg (P

Mortensen, Stefan Peter; Svendsen, Jesper H

2013-01-01

272

Altered heart rate and blood pressure variability in mice lacking the Mas protooncogene  

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Heart rate variability is a relevant predictor of cardiovascular risk in humans. A significant genetic influence on heart rate variability is suggested, although the genes involved are ill-defined. The Mas-protooncogene encodes a G-protein-coupled receptor with seven transmembrane domains highly expressed in testis and brain. Since this receptor is supposed to interact with the signaling of angiotensin II, which is an important regulator of cardiovascular homeostasis, heart rate and blood pre...

2000-01-01

273

Decomposition of heart rate variability by adaptive filtering for estimation of cardiac vagal tone  

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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...

Han, Kedu; Nagel, Joachim H.; Hurwitz, Barry E.; Schneiderman, Neil

1991-01-01

274

Reduction of heart rate by omega-3 fatty acids and the potential underlying mechanisms  

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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...

Kang, Jing X.

2012-01-01

275

Influence of blood glucose on heart rate and cardiac autonomic function. The DESIR study.  

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OBJECTIVES: To evaluate in a general population, the relationships between dysglycaemia, insulin resistance and metabolic variables, and heart rate, heart rate recovery and heart rate variability. METHODS: Four hundred and forty-seven participants in the Data from an Epidemiological Study on the Insulin Resistance syndrome (DESIR) study were classified according to glycaemic status over the preceding 9 years. All were free of self-reported cardiac antecedents and were not taking drugs which a...

Valensi, Paul; Extramiana, Fabrice; Lange, Ce?line; Cailleau, Martine; Haggui, Abdeddayem; Maison Blanche, Pierre; Tichet, Jean; Balkau, Beverley

2011-01-01

276

Scaling graphs of heart rate time series in athletes demonstrate the VLF, LF and HF regions  

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Scaling analysis of heart rate time series has emerged as an useful tool for assessment of autonomic cardiac control. We investigate the heart rate time series of ten athletes (five males and five females), by applying detrended fluctuation analysis (DFA). High resolution ECGs are recorded under standardized resting conditions over 30 minutes and subsequently heart rate time series are extracted and artefacts filtered. We find three distinct regions of scale-invariance, whic...

Baumert, M.; Brechtel, Lm; Lock, J.; Voss, A.; Abbott, D.

2006-01-01

277

A comparison between computer-controlled and set work rate exercise based on target heart rate  

Science.gov (United States)

Two methods are compared for observing the heart rate (HR), metabolic equivalents, and time in target HR zone (defined as the target HR + or - 5 bpm) during 20 min of exercise at a prescribed intensity of the maximum working capacity. In one method, called set-work rate exercise, the information from a graded exercise test is used to select a target HR and to calculate a corresponding constant work rate that should induce the desired HR. In the other method, the work rate is controlled by a computer algorithm to achieve and maintain a prescribed target HR. It is shown that computer-controlled exercise is an effective alternative to the traditional set work rate exercise, particularly when tight control of cardiovascular responses is necessary.

Pratt, Wanda M.; Siconolfi, Steven F.; Webster, Laurie; Hayes, Judith C.; Mazzocca, Augustus D.; Harris, Bernard A., Jr.

1991-01-01

278

Heart rate variability analysis during central hypovolemia using wavelet transformation.  

Science.gov (United States)

Detection of hypovolemia prior to overt hemodynamic decompensation remains an elusive goal in the treatment of critically injured patients in both civilian and combat settings. Monitoring of heart rate variability has been advocated as a potential means to monitor the rapid changes in the physiological state of hemorrhaging patients, with the most popular methods involving calculation of the R-R interval signal's power spectral density (PSD) or use of fractal dimensions (FD). However, the latter method poses technical challenges, while the former is best suited to stationary signals rather than the non-stationary R-R interval. Both approaches are also limited by high inter- and intra-individual variability, a serious issue when applying these indices to the clinical setting. We propose an approach which applies the discrete wavelet transform (DWT) to the R-R interval signal to extract information at both 500 and 125 Hz sampling rates. The utility of machine learning models based on these features were tested in assessing electrocardiogram signals from volunteers subjected to lower body negative pressure induced central hypovolemia as a surrogate of hemorrhage. These machine learning models based on DWT features were compared against those based on the traditional PSD and FD, at both sampling rates and their performance was evaluated based on leave-one-subject-out fold cross-validation. Results demonstrate that the proposed DWT-based model outperforms individual PSD and FD methods as well as the combination of these two traditional methods at both sample rates of 500 Hz (p value <0.0001) and 125 Hz (p value <0.0001) in detecting the degree of hypovolemia. These findings indicate the potential of the proposed DWT approach in monitoring the physiological changes caused by hemorrhage. The speed and relatively low computational costs in deriving these features may make it particularly suited for implementation in portable devices for remote monitoring. PMID:23371800

Ji, Soo-Yeon; Belle, Ashwin; Ward, Kevin R; Ryan, Kathy L; Rickards, Caroline A; Convertino, Victor A; Najarian, Kayvan

2013-06-01

279

Association between the Rating Perceived Exertion, Heart Rate and Blood Lactate in Successive Judo Fights (Randori)  

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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. Befor...

Braulio Henrique Magnani Branco; Luis Miguel Massuça; Leonardo Vidal Andreato; Bianca Miarka; Luis Monteiro; Bruno Ferreira Marinho; Emerson Fanchini

2013-01-01

280

Correlation of heart rate and radionuclide index of left ventricular contraction and relaxation  

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Since the cardiac function indices derived from radionuclide ventriculography (RNV) are considered to depend on the heart rate, we studied the relationship between systolic or diastolic indices and heart rates in patients with normal RNV and devised a method of correcting these indices according to the heart rate. For the systolic indices, the heart rate showed significant correlation with ET (r=-0.640), PER (r=0.791) and TPE (r=-0.401) but not with EF, 1/3 EF, MNSER or 1/3 MNSER. For the diastolic indices, the heart rate correlated well with FT (r=-0.938), RFT (r=-0.736), SFT (r=-0.803), 1/3 FF (r=-0.758), PFR (r=0.759), 1/3 PFR (r=0.742) and TPF (r=-0.389) but not with AFT, 1/3 MNDFR or AFF. These results indicate that many systolic and diastolic indices derived from RNV are affected by the heart rate, So when cardiac function is evaluated with the use of radionuclide indices, those which are independent of the heart rate should be used, or they should be corrected for the heart rate. As a method of correction, we proposed a rotating method obtained by manipulation of the regression equation of heart rates and indices. This new method is certain and easier to use when the correcting equations are set into a computer program. (author).

Adachi, Haruhiko; Sugihara, Hiroki; Nakagawa, Hiroaki; Inagaki, Suetsugu; Kubota, Yasushi; Nakagawa, Masao (Kyoto Prefectural Univ. of Medicine (Japan))

1990-11-01

 
 
 
 
281

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

Science.gov (United States)

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 ? 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 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. PMID:23868686

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

2014-02-01

282

The Development of a Microcontroller Based LowCost Heart Rate Counter for Health Care Systems  

Directory of Open Access Journals (Sweden)

Full Text Available The heart rate is one of the significant physiological parameters of the human cardiovascular system. Heart rate is the number of times the heart beats per minute. Heart rate data reflects various physiological states such as biological workload, stress at work and concentration on tasks, drowsiness and the active state of the autonomic nervous system. Human cardiac dynamics are driven by the complex nonlinear interactions of two competing forces: sympathetic regulation increases and parasympathetic regulation decreases the heart rate. Thus, monitoring of heart rate plays a significant role in providing the status of cardiovascular system and clinically correlated information to medical professionals. Heart rate measurement is also regarded as an essential parameter in patient care monitoring system.Heart rate can be measured either by the ECG waveform or by sensing the pulse - the rhythmic expansion and contraction of an artery as blood is forced through it by the regular contractions of the heart. The pulse can be felt from those areas where the artery is close to the skin. This paper highlights on the design of a microcontroller (PIC series based heart rate counter that is able to capture the pulse from finger tip by sensing the change in blood volume. The heart rates of fifteen healthy normal subjects (students of age 21-22 yrs. both in relaxed and excited states were measured using the designed device and a standard heart rate measuring device. The outputs of the measured device were satisfactory. Also, the designed device, being noninvasive one, can easily find its place in health care monitoring system.

Souvik Das

2013-02-01

283

Chaotic signatures of heart rate variability and its power spectrum in health, aging and heart failure.  

Science.gov (United States)

A paradox regarding the classic power spectral analysis of heart rate variability (HRV) is whether the characteristic high- (HF) and low-frequency (LF) spectral peaks represent stochastic or chaotic phenomena. Resolution of this fundamental issue is key to unraveling the mechanisms of HRV, which is critical to its proper use as a noninvasive marker for cardiac mortality risk assessment and stratification in congestive heart failure (CHF) and other cardiac dysfunctions. However, conventional techniques of nonlinear time series analysis generally lack sufficient sensitivity, specificity and robustness to discriminate chaos from random noise, much less quantify the chaos level. Here, we apply a 'litmus test' for heartbeat chaos based on a novel noise titration assay which affords a robust, specific, time-resolved and quantitative measure of the relative chaos level. Noise titration of running short-segment Holter tachograms from healthy subjects revealed circadian-dependent (or sleep/wake-dependent) heartbeat chaos that was linked to the HF component (respiratory sinus arrhythmia). The relative 'HF chaos' levels were similar in young and elderly subjects despite proportional age-related decreases in HF and LF power. In contrast, the near-regular heartbeat in CHF patients was primarily nonchaotic except punctuated by undetected ectopic beats and other abnormal beats, causing transient chaos. Such profound circadian-, age- and CHF-dependent changes in the chaotic and spectral characteristics of HRV were accompanied by little changes in approximate entropy, a measure of signal irregularity. The salient chaotic signatures of HRV in these subject groups reveal distinct autonomic, cardiac, respiratory and circadian/sleep-wake mechanisms that distinguish health and aging from CHF. PMID:19183809

Wu, Guo-Qiang; Arzeno, Natalia M; Shen, Lin-Lin; Tang, Da-Kan; Zheng, Da-An; Zhao, Nai-Qing; Eckberg, Dwain L; Poon, Chi-Sang

2009-01-01

284

Effect of dietary omega-3 fatty acids on the heart rate and the heart rate variability responses to myocardial ischemia or submaximal exercise  

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The consumption of omega-3 polyunsaturated fatty acids (n-3 PUFAs) has been reported to decrease resting heart rate (HR) and increase heart rate variability (HRV). However, the effects of n-3 PUFAs on these variables in response to a physiological stress (e.g., exercise or acute myocardial ischemia), particularly in postmyocardial infarction (MI) patients, are unknown. Therefore, HR and HRV (high frequency and total R-R interval variability) were evaluated at rest, during submaximal exercise,...

Billman, George E.; Harris, William S.

2011-01-01

285

Investigation of the Effect of Occupational Noise Exposure on Blood Pressure and Heart Rate of Steel Industry Workers  

Science.gov (United States)

Background and Objectives. This study aimed to investigate the effect of noise exposure on blood pressure and heart rate of steel industry workers. Materials and Methods. In the present cross-sectional study, 50 workers were selected from a steel company in Fars province, Iran, and exposed to 85, 95, and 105?dB noise levels for 5 minutes. The participants' blood pressure and heart rate were measured using Beurer BC16 pulse meter both before and after the exposure. Results. The study results showed no significant difference in blood pressure and heart rate before and after the exposure. However, the workers' systolic blood pressure had increased compared to before the exposure; of course, the difference was not statistically significant (P > 0.05). Besides, although the subjects' heart rate had reduced in comparison to before the exposure, the difference was not statistically significant (P > 0.05). Conclusion. No significant change was observed in blood pressure and heart rate after acute exposure to 85, 95, and 105?dB noise levels.

Zamanian, Zahra; Rostami, Reza; Hasanzadeh, Jafar; Hashemi, Hassan

2013-01-01

286

Entertainment Capture through Heart Rate Activity in Physical Interactive Playgrounds  

DEFF Research Database (Denmark)

An approach for capturing and modeling individual entertainment (â??funâ?) preferences is applied to users of the innovative Playware playground, an interactive physical playground inspired by computer games, in this study. The goal is to construct, using representative statistics computed from childrenâ??s physiological signals, an estimator of the degree to which games provided by the playground engage the players. For this purpose childrenâ??s heart rate (HR) signals, and their expressed preferences of how much â??funâ? particular game variants are, are obtained from experiments using games implemented on the Playware playground. A comprehensive statistical analysis shows that childrenâ??s reported entertainment preferences correlate well with specific features of the HR signal. Neuro-evolution techniques combined with feature set selection methods permit the construction of user models that predict reported entertainment preferences given HR features. These models are expressed as artificial neural networks and are demonstrated and evaluated on two Playware games and two control tasks requiring physical activity. The best network is able to correctly match expressed preferences in 64% of cases on previously unseen data (pâ??value 6 · 10â??5). The generality of the methodology, its limitations, its usability as a real-time feedback mechanism for entertainment augmentation and as a validation tool are discussed. Udgivelsesdato: February

Yannakakis, Georgios; Hallam, John

2008-01-01

287

Multiscale analysis of heart rate variability in nonstationary environments  

Directory of Open Access Journals (Sweden)

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.

BrianM.Gurbaxani

2013-05-01

288

Feature selection using genetic algorithms for fetal heart rate analysis.  

Science.gov (United States)

The fetal heart rate (FHR) is monitored on a paper strip (cardiotocogram) during labour to assess fetal health. If necessary, clinicians can intervene and assist with a prompt delivery of the baby. Data-driven computerized FHR analysis could help clinicians in the decision-making process. However, selecting the best computerized FHR features that relate to labour outcome is a pressing research problem. The objective of this study is to apply genetic algorithms (GA) as a feature selection method to select the best feature subset from 64 FHR features and to integrate these best features to recognize unfavourable FHR patterns. The GA was trained on 404 cases and tested on 106 cases (both balanced datasets) using three classifiers, respectively. Regularization methods and backward selection were used to optimize the GA. Reasonable classification performance is shown on the testing set for the best feature subset (Cohen's kappa values of 0.45 to 0.49 using different classifiers). This is, to our knowledge, the first time that a feature selection method for FHR analysis has been developed on a database of this size. This study indicates that different FHR features, when integrated, can show good performance in predicting labour outcome. It also gives the importance of each feature, which will be a valuable reference point for further studies. PMID:24854596

Xu, Liang; Redman, Christopher W G; Payne, Stephen J; Georgieva, Antoniya

2014-07-01

289

Analysis of heart rate variability after a ranger training course.  

Science.gov (United States)

We studied the effects of prolonged physical activities on resting heart rate variability (HRV) during a training session attended by 23 cadets of the French military academy. This course lasts 1 month and is concluded by a 5-day field exercise simulation with physical and psychological stress. Data collection took place before (B) and immediately at the end (E) of the course. It included HRV recordings during a stand test (5 minutes lying down and 5 minutes standing), with a Polar R-R monitor, followed by blood sampling to assay plasma testosterone. The results (B and E) showed that the testosterone level fell by approximately 28.6 +/- 7%, indicating a high level of fatigue. During the stand test, the total power (TP) of the HRV spectrum increased in a supine position. The TP of B was 5,515.7 ms2 (SE, 718.4) and of E was 13018.9 ms2 (SE, 2,539.2; p fatigue. PMID:15379067

Jouanin, Jean-Claude; Dussault, Caroline; Pérès, Michel; Satabin, Pascale; Piérard, Christophe; Guézennec, Charles Yannick

2004-08-01

290

Muscle metaboreflex and autonomic regulation of heart rate in humans.  

Science.gov (United States)

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 exercise, (2) isolated muscle metaboreflex activation (post-exercise ischaemia; PEI) following leg cycling exercise, (3) isometric handgrip followed by PEI. Trials were undertaken under control (no drug), ?1-adrenergic blockade (metoprolol) and parasympathetic blockade (glycopyrrolate) conditions. HR increased with partial flow restriction during leg cycling in the control condition (11 ± 2 beats min(-1); P 0.05 between conditions). During PEI following handgrip, HR was similarly elevated from rest under control and parasympathetic blockade (4 ± 1 vs. 4 ± 2 beats min(-1); P > 0.05 between conditions) conditions, but attenuated with ?-adrenergic blockade (0.2 ± 1 beats min(-1); P > 0.05 vs. rest). Thus muscle metaboreflex activation-mediated increases in HR are principally attributable to increased cardiac sympathetic activity, and only following exercise with a large muscle mass (PEI following leg cycling) is there a contribution from the partial withdrawal of cardiac parasympathetic tone. PMID:23713032

Fisher, James P; Adlan, Ahmed M; Shantsila, Alena; Secher, J Frederik; Sørensen, Henrik; Secher, Niels H

2013-08-01

291

Clinical Application of Heart Rate Variability after Acute Myocardial Infarction  

Directory of Open Access Journals (Sweden)

Heart rate (HR variability has been extensively studied in patients surviving an acute myocardial infarction (AMI. The majority of studies have shown that patients with reduced or abnormal HR variability/turbulence have an increased risk of mortality within few years after an AMI. Various measures of HR dynamics, such as time-domain, spectral, and non-linear measures of HR variability, as well as HR turbulence, have been used in risk stratification of post-AMI patients. The prognostic power of various measures, except of those reflecting rapid R-R interval oscillations, has been almost identical, albeit some non-linear HR variability measures, such as short-term fractal scaling exponent, and HR turbulence, have provided somewhat better prognostic information than the others. Abnormal HR variability predicts both sudden and non-sudden cardiac death after AMI. Because of remodeling of the arrhythmia substrate after AMI, early measurement of HR variability to identify those at high risk should likely be repeated later in order to assess the risk of fatal arrhythmia events. Future randomized trials using HR variability/turbulence as one of the pre-defined inclusion criteria will show whether routine measurement of HR variability/turbulence will become a routine clinical tool for risk stratification of post-AMI patients.

HeikkiVeliHuikuri

2012-02-01

292

Increased heart rate and atherosclerosis: Potential implications of ivabradine therapy  

Directory of Open Access Journals (Sweden)

Full Text Available Despite all the therapeutic advances in the field of cardiology, cardiovascular diseases, and in particular coronary artery disease, remain the leading cause of death and disability worldwide, thereby underlining the importance of acquiring new therapeutic options in this field. A reduction in elevated resting heart rate (HR has long been postulated as a therapeutic approach in the management of cardiovascular disease. An increased HR has been shown to be associated with increased progression of coronary atherosclerosis in animal models and patients. A high HR has also been associated with a greatly increased risk of plaque rupture in patients with coronary atherosclerosis. Endothelial function may be an important link between HR and atherosclerosis. An increased HR has been shown experimentally to cause endothelial dysfunction. Inflammation plays a significant role in the pathogenesis and progression of atherosclerosis. In the literature, there is data that shows an association between HR and circulating markers of vascular inflammation. In addition, HR reduction by pharmacological intervention with ivabradine (a selective HR-lowering agent that acts by inhibiting the pacemaker ionic current If in sinoatrial node cells reduces the formation of atherosclerotic plaques in animal models of lipid-induced atherosclerosis. The aim of this editorial is to review the possible role of ivabradine on atherosclerosis.

Alberto Dominguez-Rodriguez

2011-04-01

293

Heart rate variability in patients with allergic rhinitis.  

Science.gov (United States)

Considering the role of autonomic imbalance in the pathogenesis of hypersensitivity reactions, we evaluated the autonomic system through time-domain analysis of heart rate variability (HRV) in patients with allergic rhinitis. Twenty-four patients with allergic rhinitis and 22 healthy subjects (mean age, 41 +/- 8 years and 37 +/- 9 years, respectively) were enrolled in the study. The diagnosis of allergic rhinitis was based on the history, symptoms, and skin prick tests results. Twenty-four-hour ambulatory electrocardiographic recordings were obtained, and the time-domain indices were analyzed. Analysis of HRV revealed that the SD of normal RR intervals, SD of successive differences in normal cycles, and HRV triangular index were not significantly different between the groups, but the root mean square successive difference, number of RR intervals exceeding 50 milliseconds, and percentage difference between adjacent normal RR intervals exceeding >50 milliseconds were significantly greater in the study group, compared with the control group. Our findings showed that HRV indices, which predict parasympathetic predominance, were increased in patients with allergic rhinitis. This finding shows that vagal activation is present not only in the nose but also in other systems, including the cardiovascular system. PMID:17274276

Yokusoglu, Mehmet; Ozturkt, Sami; Uzun, Mehmet; Baysan, Oben; Demirkol, Sait; Caliskaner, Zafer; Dundaroz, Rusen; Sag, Cemal; Karaayvaz, Mehmet; Isik, Ersoy

2007-01-01

294

Wavelet transform analysis of heart rate variability during myocardial ischaemia.  

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Analysis of heart rate variability (HRV) is a valuable, non-invasive method for quantifying autonomic cardiac control in humans. Frequency-domain analysis of HRV involving myocardial ischaemic episodes should take into account its non-stationary behaviour. The wavelet transform is an alternative tool for the analysis of non-stationary signals. Fourteen patients have been analysed, ranging from 40 to 64 years old and selected from the European Electrocardiographic ST-T Database (ESDB). These records contain 33 ST episodes, according to the notation of the ESDB, with durations of between 40s and 12 min. A method for analysing HRV signals using the wavelet transform was applied to obtain a time-scale representation for very low-frequency (VLF), low-frequency (LF) and high-frequency (HF) bands using the orthogonal multiresolution pyramidal algorithm. The design and implementation using fast algorithms included a specially adapted decomposition quadrature mirror filter bank for the frequency bands of interest. Comparing a normality zone against the ischaemic episode in the same record, increases in LF (0.0112 +/- 0.0101 against 0.0175 +/- 0.0208 s2 Hz(-1); pwavelet analysis provides useful information for the assessment of dynamic changes and patterns of HRV during myocardial ischaemia. PMID:11954711

Gamero, L G; Vila, J; Palacios, F

2002-01-01

295

Increased Non-Gaussianity of Heart Rate Variability Predicts Cardiac Mortality after an Acute Myocardial Infarction  

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Non-Gaussianity index (?) is a new index of heart rate variability (HRV) that characterizes increased probability of the large heart rate deviations from its trend. A previous study has reported that increased ? is an independent mortality predictor among patients with chronic heart failure. The present study examined predictive value of ? in patients after acute myocardial infarction (AMI). Among 670 post-AMI patients, we performed 24-h Holter monitoring to assess ? and other HRV predict...

Hayano, Junichiro; Kiyono, Ken; Struzik, Zbigniew R.; Yamamoto, Yoshiharu; Watanabe, Eiichi; Stein, Phyllis K.; Watkins, Lana L.; Blumenthal, James A.; Carney, Robert M.

2011-01-01

296

Assessment of electrocardiography, echocardiography, and heart rate variability in dynamic and static type athletes  

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Full Text Available Mehrnoush Toufan,1 Babak Kazemi,1 Fariborz Akbarzadeh,1 Amin Ataei,1 Majid Khalili21Cardiovascular Research Center, Tabriz University of Medical Sciences, Tabriz, Iran; 2Azerbaijan National Academy of Sciences, Baku, AzerbaijanBackground: Over the last two decades, morphological cardiac changes induced by athletic conditioning have been of great interest. Therefore, several studies have been orchestrated to delineate electrocardiography (ECG, echocardiography, and heart rate variability (HRV findings in athletes.Purpose: To assess the ECG, echocardiography, and HRV in a group of dynamic and static type athletes.Methods: Fifty professional athletes (20 static and 30 dynamic exercise athletes and 50 healthy nonathletes (control group were recruited. Standard 12-lead ECG and transthoracic echocardiography was performed on all athletes and the control group. Through echocardiography, variables including left ventricular (LV end-diastolic/systolic diameter, LV mass, and left atrial volume index were measured. In addition, both the athletes and the control group underwent ECG Holter monitoring for 15 minutes and several parameters related to HRV (time and frequency domain were recorded.Results: The most common ECG abnormalities among the athletes were sinus bradycardia and incomplete right bundle branch block. LV end-diastolic diameter and left atrial volume index were significantly greater in the dynamic athletes (P < 0.001. LV end-systolic diameter was significantly lower in the static group (P < 0.001. LV mass of the dynamic and static athletes was significantly greater than that of the controls (P < 0.001. Among the ECG Holter monitoring findings, the dynamic athletes had lower systolic blood pressure than the controls (P = 0.01. Heart rate was lowest in the control group (P < 0.001.Conclusion: The most common ECG abnormalities among adolescent Iranian athletes were sinus bradycardia and incomplete right bundle branch block. Static exercise seemed to reduce LV end-systolic diameter, while dynamic exercise resulted in increased LV end-diastolic diameter and left atrial volume index. Additionally, Iranian athletes showed no differences in HRV parameters, excluding heart rate and systolic blood pressure, compared with the nonathletes.Keywords: athlete's heart, electrocardiography, echocardiography, heart rate variability

Ataei A

2012-07-01

297

Target heart rate to determine the normal value of coronary flow reserve during dobutamine stress echocardiography  

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Full Text Available Abstract Background The determination of coronary flow reserve (CFR is an essential concept at the moment of decision-making in ischemic heart disease. There are several direct and indirect tests to evaluate this parameter. In this sense, dobutamine stress echocardiography is one of the pharmacological method most commonly used worldwide. It has been previously demonstrated that CFR can be determined by this technique. Despite our wide experience with dobutamine stress echocardiography, we ignored the necessary heart rate to consider sufficient the test for the analysis of CFR. For this reason, our main goal was to determine the velocity of coronary flow in each stage of dobutamine stress echocardiography and the heart rate value necessary to double the baseline values of coronary flow velocity in the territory of the left anterior descending (LAD coronary artery. Methods A total of 33 consecutive patients were analyzed. The patients included had low risk for coronary artery disease. All the participants underwent dobutamine stress echocardiography and coronary artery flow velocity was evaluated in the distal segment of LAD coronary artery using transthoracic color-Doppler echocardiography. Results The feasibility of determining CFR in the territory of the LAD during dobutamine stress echocardiography was high: 31/33 patients (94%. Mean CFR was 2.67 at de end of dobutamine test. There was an excellent concordance between delta HR (difference between baseline HR and maximum HR and the increase in the CFR (correlation coefficient 0.84. In this sense, we found that when HR increased by 50 beats, CFR was ? 2 (CI 93-99.2%. In addition, 96.4% of patients reached a CFR ? 2 (IC 91.1 - 99% at 75% of their predicted maximum heart rate. Conclusions We found that the feasibility of dobutamine stress echocardiography to determine CFR in the territory of the LAD coronary artery was high. In this study, it was necessary to achieve a difference of 50 bpm from baseline HR or at least 75% of the maximum predicted heart rate to consider sufficient the test for the analysis of CFR.

Rousse Maria G

2011-04-01

298

Effect of Cardiac Rehabilitation Program on Heart Rate Recovery after Percutaneous Coronary Intervention and Coronary Artery Bypass Grafting  

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Full Text Available Background: The objective of this study was to evaluate the effect of a hospital-based cardiac rehabilitation program on heart rate recovery (HRR in patients who received percutaneous coronary intervention (PCI or coronary artery bypass grafting (CABG. Methods: Two hundred forty patients, who completed 24 sessions of a cardiac rehabilitation program (phase 2 after PCI (n=62 or CABG (n=178 at the rehabilitation department of Tehran Heart Center were included in the present study. Demographic and clinical characteristics and exercise capacity at baseline and at follow-up were compared between the two groups. The main outcome measurements were: Resting heart rate, peak heart rate, and HRR.Results: All the patients showed significant improvements in heart rate parameters from the baseline to the last sessions. The profile of atherosclerotic risk factors (except for diabetes mellitus was similar between the PCI and CABG subjects. After eight weeks of cardiac rehabilitation, HRR increased averagely about 17 and 21 bpm among the CABG and PCI patients, respectively (p=0.019. Conclusion: The results of the present study were indicative of an increase in HRR over 1 minute in patients irrespective of their initial revascularization modality (i.e. PCI or CABG after the completion of cardiac rehabilitation. Be that as it may, the PCI patients achieved greater improvement in HRR by comparison with the CABG patients.

Ali Abbasi

2008-07-01

299

Value of heart rate variability parameters in prognosis of intrauterine infection of infants with cytomegalovirus  

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Full Text Available Spectral analysis of heart rate variability (HRV in 35 infants with congenital cytomegalovirus (CMV infection and 37 non-infected infants (mean age 1.83 ± 0.09 years was conducted. Analysis of distribution of relative and range parameters characterizing heart rate density in various ranges and subranges allowed defining confident signs typical of intrauterine CMV infection.

Shoira Agzamova

2010-12-01

300

Decreased nighttime heart rate variability is associated with increased stroke risk  

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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.

Binici, Zeynep; Mouridsen, Mette Rauhe

2011-01-01

 
 
 
 
301

The Influence of Motor Impairment on Autonomic Heart Rate Modulation among Children with Cerebral Palsy  

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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…

Zamuner, Antonio Roberto; Cunha, Andrea Baraldi; da Silva, Ester; Negri, Ana Paola; Tudella, Eloisa; Moreno, Marlene Aparecida

2011-01-01

302

Nonlinear control of heart rate variability in human infants.  

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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 greater than or equal to 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 > or = to 27 weeks) where parasympathetic-sympathetic interaction and function are presumed to be less well developed. O...

1996-01-01

303

Heart Rate Recovery in the First Minute at the Six-Minute Walk Test in Patients with Heart Failure  

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Background Heart rate recovery at one minute of rest (HRR1) is a predictor of mortality in heart failure (HF), but its prognosis has not been assessed at six-minute walk test (6MWT) in these patients. Objective This study aimed to determine the HRR1 at 6MWT in patients with HF and its correlation with six-minute walk distance (6MWD). Methods Cross-sectional, controlled protocol with 161 individuals, 126 patients with stable systolic HF, allocated into 2 groups (G1 and G2) receiving or not ?-blocker and 35 volunteers in control group (G3) had HRR1 recorded at the 6MWT. Results HRR1 and 6MWD were significantly different in the 3 groups. Mean values of HRR1 and 6MWD were: HRR1 = 12 ± 14 beat/min G1; 18 ± 16 beat/min G2 and 21 ± 13 beat/min G3; 6MWD = 423 ± 102 m G1; 396 ± 101m G2 and 484 ± 96 m G3 (p < 0.05). Results showed a correlation between HRR1 and 6MWD in G1(r = 0.3; p = 0.04) and in G3(r = 0.4; p= 0.03), but not in G2 (r= 0.12; p= 0.48). Conclusion HRR1 response was attenuated in patients using ?B and showed correlation with 6MWD, reflecting better exercise tolerance. HRR1 after 6MWT seems to represent an alternative when treadmill tests could not be tolerated.

Lindemberg, Sabrina; Chermont, Sergio; Quintao, Monica; Derossi, Milena; Guilhon, Sergio; Bernardez, Sabrina; Marchese, Luana; Martins, Wolney; Nobrega, Antonio Claudio L.; Mesquita, Evandro Tinoco

2014-01-01

304

Chaotic Behavior of Heart Rate Signals during Chi and Kundalini Meditation  

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Full Text Available Nonlinear dynamics has been introduced to the analysis of biological data and increasingly recognized to be functionally relevant. The aim of this study is to quantify and compare the contribution of nonlinear and chaotic dynamics of human heart rate variability during two forms of meditation: (i Chinese Chi (or Qigong meditation and (ii Kundalini Yoga meditation. For this purpose, Poincare plots, Lyapunov exponents and Hurst exponents of heart rate variability signals were analyzed. In this study, we examined the different behavior of heart rate signals during two specific meditation techniques. The results show that heart rate signals became more periodic and their chaotic behavior was decreased in both techniques of meditation. Therefore, nonlinear chaotic indices may serve as a quantitative measure for psychophysiological states such as meditation. In addition, different forms of meditation appear to differentially alter specific components of heart rate signals.

Atefeh Goshvarpour

2012-03-01

305

Reduction of Heart Rate by Omega-3 Fatty Acids and the Potential Underlying Mechanisms  

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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.

JingXuanKang

2012-10-01

306

Chick embryo heart rate during the last week of incubation: population studies.  

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1. A technique has been developed for the study of embryonic heart rate during the last week of incubation in a population of 84 embryos. 2. Heart rate is characteristic for a particular embryo but there are clear differences between individuals. 3. The population mean heart rate decreased from 262 beats/min at 14 d to a minimum of 250 beats/min at 19-5 d and then increased rapidly to more than 270 beats/min before hatching. 4. This pattern was repeatable and independent of the flock age. 5. Embryonic heart rate was also independent of egg size and hatching time. 6. The heart rate of male embryos was one to two beats/min lower than that of females. PMID:1276968

Laughlin, K F; Lundy, H; Tait, J A

1976-05-01

307

Estimating mental fatigue based on electroencephalogram and heart rate variability  

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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.

Zhang, Chong; Yu, Xiaolin

2010-01-01

308

Heart rate affects endothelial function in essential hypertension.  

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Increased heart rate (HR) is a risk factor for cardiovascular morbidity and mortality in the general population and in some clinical conditions. Endothelial dysfunction is an adverse prognostic factor for cardiovascular events. The aim of the study was to evaluate the effect of HR on central hemodynamic parameters and endothelial function in hypertension. We evaluated forearm blood flow (FBF) response to intra-arterial infusion of acetylcholine (ACh) and sodium nitroprusside (SNP) in 30 patients with HR ?60 min(-1) and 30 with HR ?80 min(-1). The FBF was measured by strain-gauge plethysmography. Transesophageal atrial pacing was used to increase the HR. Radial artery applanation tonometry and pulse wave analysis were used to derive central aortic pressures and correlate hemodynamic indices. The FBF response to ACh is lower in hypertensives with HR ?60 min(-1) than in those with HR ?80 min(-1) (10.6 ± 4.2 vs. 13.6 ± 5.1 ml × 100 ml(-1) of tissue × min(-1), P < 0.001). Vascular resistance decreases to 9.3 ± 2.8 U in patients with lower HR versus 7.2 ± 2.1 U in those with higher HR (P = 0.002). The FBF response to SNP is similar in both groups. Central systolic and pulse pressure are higher in bradycardic patients than in those with HR ?80 min(-1) (140 ± 8 vs. 131 ± 8 mmHg, P = 0.0001 and 49 ± 10 vs. 39 ± 11 mmHg, P = 0.0001). All central hemodynamic parameters decrease during incremental atrial pacing. Augmentation index is the strongest predictor of endothelial dysfunction at multivariate analysis. These findings demonstrate that low HR affects endothelium-dependent vasodilation in hypertension. Increased central aortic pressure and hemodynamic correlates seem to be the underlying mechanisms by which bradycardia interferes with endothelium-dependent reactivity. PMID:21559746

Maio, Raffaele; Miceli, Sofia; Sciacqua, Angela; Leone, Giulia Galiano; Bruni, Rosamaria; Naccarato, Paola; Martino, Francesco; Sesti, Giorgio; Perticone, Francesco

2013-04-01

309

Reduced Heart Rate Variability Among Youth With Type 1 Diabetes  

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OBJECTIVE This study compared heart rate variability (HRV) parameters in youth with and without type 1 diabetes and explored potential contributors of altered HRV. RESEARCH DESIGN AND METHODS HRV parameters were measured among 354 youth with type 1 diabetes (mean age 18.8 years, diabetes duration 9.8 years, and mean A1C 8.9%) and 176 youth without diabetes (mean age 19.2 years) participating in the SEARCH CVD study. Multiple linear regression was used to assess the relationship between diabetes status and HRV parameters, adjusting for covariates. RESULTS Compared with control subjects, youth with type 1 diabetes had reduced overall HRV (10.09 ms lower SD of NN intervals [SDNN]) and markers of parasympathetic loss (13.5 ms reduced root mean square successive difference of NN intervals [RMSSD] and 5.2 normalized units (n.u.) reduced high frequency [HF] power) with sympathetic override (5.2 n.u. increased low frequency [LF] power), independent of demographic, anthropometric, and traditional cardiovascular risk factors. Older age, female sex, higher LDL cholesterol and triglyceride levels, and presence of microalbuminuria were independently associated with lower HRV but did not account for the observed differences between youth with and without diabetes. Youth with type 1 diabetes and A1C levels ?7.5% had significantly worse HRV parameters than control subjects; however, in youth with optimal glycemic control (A1C cardiac autonomic neuropathy: reduced overall HRV and parasympathetic loss with sympathetic override. The main driver of these subclinical abnormalities appears to be hyperglycemia.

Jaiswal, Mamta; Urbina, Elaine M.; Wadwa, R. Paul; Talton, Jennifer W.; D'Agostino, Ralph B.; Hamman, Richard F.; Fingerlin, Tasha E.; Daniels, Stephen; Marcovina, Santica M.; Dolan, Lawrence M.; Dabelea, Dana

2013-01-01

310

Heart rate variability in normal and pathological sleep  

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Full Text Available Sleep is a physiological process involving different biological systems, from molecular to organ level; its integrity is essential for maintaining health and homeostasis in human beings. Although in the past sleep has been considered a state of quiet, experimental and clinical evidences suggest a noteworthy activation of different biological systems during sleep. A key role is played by the autonomic nervous system (ANS, whose modulation regulates cardiovascular functions during sleep onset and different sleep stages. Therefore, an interest on the evaluation of autonomic cardiovascular control in health and disease is growing by means of linear and non linear heart rate variability (HRV analyses. The application of classical tools for ANS analysis, such as HRV during physiological sleep, showed that the rapid eye movement (REM stage is characterized by a likely sympathetic predominance associated with a vagal withdrawal, while the opposite trend is observed during non-REM sleep. More recently, the use of non linear tools, such as entropy-derived indices, have provided new insight on the cardiac autonomic regulation, revealing for instance changes in the cardiovascular complexity during REM sleep, supporting the hypothesis of a reduced capability of the cardiovascular system to deal with stress challenges. Interestingly, different HRV tools have been applied to characterize autonomic cardiac control in different pathological conditions, from neurological sleep disorders to sleep disordered breathing (SDB. In summary, linear and non linear analysis of HRV are reliable approaches to assess changes of autonomic cardiac modulation during sleep both in health and diseases. The use of these tools could provide important information of clinical and prognostic relevance.

EleonoraTobaldini

2013-10-01

311

Normative references of heart rate variability and salivary alpha-amylase in a healthy young male population  

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Full Text Available Abstract Background This study aimed to present normative reference values of heart rate variability and salivary alpha-amylase in a healthy young male population with a particular focus on their distribution and reproducibility. Methods The short-term heart rate variability of 417 young healthy Japanese men was studied. Furthermore, salivary alpha-amylase was measured in 430 men. The average age of the subjects were 21.9 years with standard deviation of 1.6 years. Interindividual variations in heart rate variability indices and salivary alpha-amylase levels were plotted as histograms. Data are presented as the mean, median, standard deviation, coefficient of variation, skewness, kurtosis, and fifth and 95th percentiles of each physiological index. Results Mean recorded values were heart period 945.85 ms, log-transformed high frequency component 9.84 ln-ms2, log-transformed low frequency component 10.42 ln-ms2, log-transformed low frequency to high frequency ratio 0.58 ln-ratio, standard deviation of beat-to-beat interval 27.17 ms and root mean square of successive difference 37.49 ms. The mean value of raw salivary alpha-amylase was 17.48 U/mL, square root salivary alpha-amylase 3.96 sqrt[U/mL] and log-transformed salivary alpha-amylase 2.65 ln[U/mL]. Log-transformed heart rate variability indices exhibited almost symmetrical distributions; however, time-domain indices of heart rate variability (standard deviation of beat-to-beat interval and root mean square of successive difference exhibited right-skewed (positive skewness distributions. A considerable right-skewed distribution was observed for raw salivary alpha-amylase. Logarithmic transformation improved the distribution of salivary alpha-amylase, although square root transformation was insufficient. The day-to-day reproducibility of these indices was assessed using intraclass correlation coefficients. Intraclass correlation coefficients of most heart rate variability and salivary indices were approximately 0.5 to 0.6. Intraclass correlation coefficients of raw salivary markers were approximately 0.6, which was similar to those of heart rate variability; however, log transformation of the salivary markers did not considerably improve their reproducibility. Correlations between sympathetic indicators of heart rate variability and salivary alpha-amylase were not observed. Conclusion Because the sample population examined in this study involved limited age and gender variations, the present results were independent of these factors and were indicative of pure interindividual variation.

Kobayashi Hiromitsu

2012-04-01

312

Simultaneous measurement of breathing rate and heart rate using a microbend multimode fiber optic sensor.  

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We propose and demonstrate the feasibility of using a highly sensitive microbend multimode fiber optic sensor for simultaneous measurement of breathing rate (BR) and heart rate (HR). The sensing system consists of a transceiver, microbend multimode fiber, and a computer. The transceiver is comprised of an optical transmitter, an optical receiver, and circuits for data communication with the computer via Bluetooth. Comparative experiments conducted between the sensor and predicate commercial physiologic devices showed an accuracy of ±2 bpm for both BR and HR measurement. Our preliminary study of simultaneous measurement of BR and HR in a clinical trial conducted on 11 healthy subjects during magnetic resonance imaging (MRI) also showed very good agreement with measurements obtained from conventional MR-compatible devices. PMID:24788372

Chen, Zhihao; Lau, Doreen; Teo, Ju Teng; Ng, Soon Huat; Yang, Xiufeng; Kei, Pin Lin

2014-05-01

313

Simultaneous measurement of breathing rate and heart rate using a microbend multimode fiber optic sensor  

Science.gov (United States)

We propose and demonstrate the feasibility of using a highly sensitive microbend multimode fiber optic sensor for simultaneous measurement of breathing rate (BR) and heart rate (HR). The sensing system consists of a transceiver, microbend multimode fiber, and a computer. The transceiver is comprised of an optical transmitter, an optical receiver, and circuits for data communication with the computer via Bluetooth. Comparative experiments conducted between the sensor and predicate commercial physiologic devices showed an accuracy of ±2 bpm for both BR and HR measurement. Our preliminary study of simultaneous measurement of BR and HR in a clinical trial conducted on 11 healthy subjects during magnetic resonance imaging (MRI) also showed very good agreement with measurements obtained from conventional MR-compatible devices.

Chen, Zhihao; Lau, Doreen; Teo, Ju Teng; Ng, Soon Huat; Yang, Xiufeng; Kei, Pin Lin

2014-05-01

314

Altered heart rate dynamics associated with antipsychotic-induced subjective restlessness in patients with schizophrenia  

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Full Text Available Jong-Hoon Kim,1,2 Jun-Hyung Ann,2 Jinyoung Lee,1 Mee-Hee Kim,1 Ah-Young Han1 1Department of Psychiatry, Gil Medical Center, 2Graduate School of Medicine, Gachon University, Incheon, South Korea Background: Antipsychotic-induced subjective inner restlessness is one of the common and distressing adverse effects associated with antipsychotics; however, its underlying neurobiological basis is not well understood. We examined the relationship between antipsychotic-induced subjective inner restlessness and autonomic neurocardiac function. Methods: Twenty-two schizophrenia patients with antipsychotic-induced subjective restlessness, 28 schizophrenia patients without antipsychotic-induced subjective restlessness, and 28 matched healthy control subjects were evaluated. Assessments of the linear and nonlinear complexity measures of heart rate dynamics were performed. Multivariate analysis of variance and correlation analysis were conducted. Results: The mean interbeat (RR interval value was significantly higher in control subjects than in patients with and without antipsychotic-induced subjective restlessness (P < 0.05. The low frequency/high frequency ratio was significantly higher in patients with antipsychotic-induced subjective restlessness than in control subjects and in patients without antipsychotic-induced subjective restlessness (P < 0.05, while the approximate entropy value was significantly lower in patients with antipsychotic-induced subjective restlessness than in control subjects and in patients without antipsychotic-induced subjective restlessness (P < 0.05. Correlation analyses controlling for psychotic symptom severity showed that the degree of antipsychotic-induced restlessness had a significant negative correlation with the value of approximate entropy (P < 0.05. Conclusion: The results indicate that antipsychotic-induced subjective restlessness is associated with altered heart rate dynamics parameters, particularly the nonlinear complexity measure, suggesting that it might adversely affect autonomic neurocardiac integrity. Further prospective research is necessary to elucidate the precise interrelationships and causality. Keywords: antipsychotics, subjective restlessness, heart rate dynamics

Kim JH

2013-07-01

315

Association between Frequency Domain Heart Rate Variability and Unplanned Readmission to Hospital in Geriatric Patients  

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Full Text Available Abstract Background An accurate prediction of unplanned readmission (UR after discharge from hospital can facilitate physician's decision making processes for providing better quality of care in geriatric patients. The objective of this study was to explore the association of cardiac autonomic functions as measured by frequency domain heart rate variability (HRV and 14-day UR in geriatric patients. Methods Patients admitted to the geriatric ward of a regional hospital in Chiayi county in Taiwan were followed prospectively from July 2006 to June 2007. Those with invasive tubes and those who were heavy smokers, heavy alcohol drinkers, on medications that might influence HRV, or previously admitted to the hospital within 30 days were excluded. Cardiac autonomic functions were evaluated by frequency domain indices of HRV. Multiple logistic regression was used to assess the association between UR and HRV indices adjusted for age and length of hospitalization. Results A total of 78 patients met the inclusion criteria and 15 of them were readmitted within 14 days after discharge. The risk of UR was significantly higher in patients with lower levels of total power (OR = 1.39; 95% CI = 1.04-2.00, low frequency power (LF (OR = 1.22; 95% CI = 1.03-1.49, high frequency power (HF (OR = 1.27; 95% CI = 1.02-1.64, and lower ratios of low frequency power to high frequency power (LF/HF ratio (OR = 1.96; 95% CI = 1.07-3.84. Conclusion This is the first study to evaluate the association between frequency domain heart rate variability and the risk of UR in geriatric patients. Frequency domain heart rate variability indices measured on admission were significantly associated with increased risk of UR in geriatric patients. Additional studies are required to confirm the value and feasibility of using HRV indices on admission as a non-invasive tool to assist the prediction of UR in geriatric patients.

Fu Chin-Hua

2011-02-01

316

Resting heart rate as a predictor of metabolic dysfunctions in obese children and adolescents  

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Full Text Available Abstract Background Recent studies have identified that a higher resting heart rate (RHR is associated with elevated blood pressure, independent of body fatness, age and ethnicity. However, it is still unclear whether RHR can also be applied as a screening for other risk factors, such as hyperglycemia and dyslipidemia. Thus, the purpose of the presented study was to analyze the association between RHR, lipid profile and fasting glucose in obese children and adolescents. Methods The sample was composed of 180 obese children and adolescents, aged between 7-16 years. Whole-body and segmental body composition were estimated by Dual-energy X-ray absorptiometry. Resting heart rate (RHR was measured by heart rate monitors. The fasting blood samples were analyzed for serum triglycerides, total cholesterol (TC, high-density lipoprotein cholesterol (HDL-C, low-density lipoprotein cholesterol (LDL-C, and glucose, using the colorimetric method. Results Fasting glucose, TC, triglycerides, HDL-C, LDL-C and RHR were similar in both genders. The group of obese subjects with a higher RHR presented, at a lower age, higher triglycerides and TC. There was a significant relationship between RHR, triglycerides and TC. In the multivariate model, triglycerides and TC maintained a significant relationship with RHR independent of age, gender, general and trunk adiposity. The ROC curve indicated that RHR has a high potential for screening elevated total cholesterol and triglycerides as well as dyslipidemia. Conclusion Elevated RHR has the potential to identify subjects at an increased risk of atherosclerosis development.

Freitas Júnior Ismael F

2012-01-01

317

Non-respiratory components of heart rate variability in heart transplant recipients: evidence of autonomic reinnervation?  

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1. Although the high-frequency fluctuations in R-R interval (respiratory sinus arrhythmia) observed in heart transplant recipients are not a reliable marker of reinnervation because of a previously shown direct mechanical effect of breathing, the presence of a non-respiration-related low-frequency oscillation reflects rhythms generated outside the heart, and thus could be neurally mediated. 2. To evaluate the presence of reinnervation, the spontaneous variability in R-R interval was investiga...

1994-01-01

318

Discrimination power of short-term heart rate variability measures for CHF assessment  

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In this study, we investigated the discrimination power of short-term Heart Rate Variability (HRV) for discriminating normal subjects versus Chronic Heart Failure (CHF) patients. We analyzed 1,914.40 hours of ECG of 83 patients of which 54 are normal and 29 are suffering from CHF with New York Heart Classification (NYHA) I, II, III, extracted by public databases. Following guidelines, we performed time and frequency analysis in order to measure HRV features. To assess the discrimination power...

Pecchia, Leandro; Melillo, Paolo; Bracale, Marcello

2011-01-01

319

Recuperação da freqüência cardíaca após teste de esforço em esteira ergométrica e variabilidade da freqüência cardíaca em 24 horas em indivíduos sadios Heart rate recovery after treadmill electrocardiographic exercise stress test and 24-hour heart rate variability in healthy individuals  

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Full Text Available FUNDAMENTO: A recuperação da freqüência cardíaca após o eletrocardiograma de esforço em esteira ergométrica é modulada pelo sistema nervoso autônomo. A análise da variabilidade da freqüência cardíaca (VFC pode fornecer informações valiosas sobre o controle do sistema nervoso autônomo sobre o sistema cardiovascular. OBJETIVO: O objetivo deste estudo foi testar a hipótese de associação entre a recuperação da freqüência cardíaca após teste de esforço em esteira ergométrica e a variabilidade da freqüência cardíaca. MÉTODOS: Foram estudamos 485 indivíduos sem evidência de cardiopatia com média de idade de 42± 12,1 (faixa etária de 15 a 82 anos, 281 (57.9% dos quais do sexo feminino, submetidos a um teste de esforço em esteira ergométrica e avaliação da VFC nos domínios do tempo (SDNN, SDANN, SDNNi, rMSSD e pNN50 e da freqüência (LF, HF, VLF e razão LF/HF durante monitoramento eletrocardiográfico ambulatorial de 24 horas. RESULTADOS: A recuperação da freqüência cardíaca foi de 30 ± 12 batimentos no 1º minuto e 52± 13 batimentos no 2º minuto após o exercício. Os indivíduos mais jovens de recuperaram mais rápido do 2º ao 5º minuto após o exercício (r = 0,19-0,35, P BACKGROUND: Heart rate recovery after treadmill electrocardiographic exercise stress test is modulated by the autonomic nervous system. Analysis of heart rate variability can provide useful information about autonomic control of the cardiovascular system. OBJECTIVE: The aim of the study was to test the hypothesis of association between heart recovery after treadmill electrocardiographic exercise test and heart rate variability. METHODS: We studied 485 healthy individuals aged 42± 12.1 (range 15-82 years, 281(57.9% women, submitted to treadmill electrocardiographic exercise stress tests and heart rate variability evaluations over time (SDNN, SDANN, SDNNi, rMSSD, pNN50 and frequency (LF, HF, VLF, LF/HF ratio domains in 24-hour ambulatory electrocardiographic monitoring. RESULTS: Heart rate recovery was 30± 12 beats in the 1st minute and 52± 13 beats in the 2nd minute after exercise. Younger individuals recovered faster from the 2nd to the 5th minute after exercise (r= 0.19-0.35, P< 0.05. Recovery was faster in women than in men (4± 1.1 beats lower in the 1st minute, p<0.001; 5.7± 1.2 beats lower in the 2nd minute, p<0.01; 4.1± 1.1 beats lower in the 3rd minute, p<0.001. There was no significant correlation between heart rate recovery and heart rate variability in 1st and 2nd minutes after exercise. SDNN, SDANN, SDNNi, rMSSD, and pNN50 indices demonstrated a significant correlation with heart rate recovery only at the 3rd and 4th minutes. CONCLUSION: The hypothesis of association between heart rate recovery and 24-hour heart rate variability in the first two minutes after exercise was not substantiated in this study. Heart rate recovery after exercise was associated with age and gender.

Ivana Antelmi

2008-06-01

320

Effects of Posteroanterior Thoracic Mobilization on Heart Rate Variability and Pain in Women with Fibromyalgia  

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Fibromyalgia (FM) has been associated with cardiac autonomic abnormalities and pain. Heart rate variability (HRV) is reduced in FM with autonomic tone dominated by sympathetic activity. The purpose of this study was to evaluate the effects of one session of a posteroanterior glide technique on both autonomic modulation and pain in woman with FM. This was a controlled trial with immediate followup; twenty premenopausal women were allocated into 2 groups: (i) women diagnosed with FM (n = 10) and (ii) healthy women (n = 10). Both groups received one session of Maitland mobilization grade III posteroanterior central pressure glide, at 2?Hz for 60?s at each vertebral segment. Autonomic modulation was assessed by HRV and pain by a numeric pain scale before and after the intervention. For HRV analyses, heart rate and RR intervals were recorded for 10 minutes. FM subjects demonstrated reduced HRV compared to controls. Although the mobilization technique did not significantly reduce pain, it was able to improve HRV quantified by an increase in rMSSD and SD1 indices, reflecting an improved autonomic profile through increased vagal activity. In conclusion, women with FM presented with impaired cardiac autonomic modulation. One session of Maitland spine mobilization was able to acutely improve HRV.

Reis, Michel Silva; Durigan, Joao Luiz Quagliotti; Arena, Ross; Rossi, Bruno Rafael Orsini; Mendes, Renata Goncalves; Borghi-Silva, Audrey

2014-01-01

 
 
 
 
321

Maternal heart rate patterns in the first and second stages of labor.  

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Objective. To analyze typical maternal heart rate (MHR) patterns in the first and second stages of labor. Design. Observational study. Setting. Tertiary care community hospital. Population. Normal term parturients with epidural anesthesia. Methods. Confirmed MHR and uterine activity were simultaneously recorded. The average MHR was analyzed 10 seconds before, as well as at the peak of, each contraction and/or pushing effort. Each woman contributed one datapoint at each time point to the analysis. Main outcome measure. Change in MHR during contractions. Results. First stage: 7.6±2.1 contractions per woman (n=18) were analyzed. Average MHR decreased during contractions: from 83±13 to 74±10bpm; pMHR accelerations during every pushing effort (?MHR: +35±13bpm; 88±14 to 123±17bpm; pMHR was persistently >100bpm in three women (17%) in the first stage, and in four women (27%) in the second stage. Peak MHR >140bpm occurred during pushing in 20%. Conclusion. Decreases in MHR during contractions in the first stage of labor can mimic fetal heart rate (FHR) accelerations as well as early type decelerations. Thus, first stage tracings with a low baseline and early type decelerations may be maternal in origin and FHR should be independently confirmed in such tracings. Because second stage MHR accelerations generally show greater amplitude than FHR accelerations, tracings with repetitive accelerations during contractions (especially when ? >20bpm) should be considered MHR until proven otherwise. PMID:22313165

VAN Veen, Teelkien R; Belfort, Michael A; Kofford, Shalece

2012-05-01

322

Heart rate variability, structural and functional characteristics of the left ventricle in essential arterial hypertension  

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Full Text Available For the purpose of diagnostic and treatment improvement it is necessary to investigate relationship between different pathogenetic mechanisms in essential hypertension. The aim of our study was the comparative analysis of the parameters of cardiac remodeling and neurohumoral mechanisms of heart rate variability (HRV in patients with essential arterial hypertension. 100 patients with essential arterial hypertension were included in the study. All patients went through heart rate variability parameters and left ventricle characteristics evaluation. Time and frequency domains were decreased in patients with arterial hypertension. Excess sympathetic activation takes place, parasympathetic system is depressed and it shows pathogenetic basis of disadaptation. Left ventricle hypertrophy is associated with progressive decrease of HRV and its circadian fluctuations. Concentric left ventricle hypertrophy is characterized by the most significant decrease in time and frequency domains of HRV. 1/3 of hypertensive patients with normal left ventricle geometry have diastolic dysfunction and also some decrease in time and frequency domains. In conclusion, we found that cardiac remodeling in patients with essential hypertension seems to be related to the severity of impairment of cardiac autonomic control

Khromtsova ?.?.

2010-09-01

323

A study of mental stress in recruits during parachute training based on heart rate variability  

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Full Text Available Objective To investigate the characteristics and evaluate the mental stress level of recruits during parachute training based on the heart rate variability.Methods Twenty new parachutists were allowed to parachute for seven times.The electrocardiograms were recorded together with data from pilot physiological parameter recorder worn by the parachutists.The data analysis system which matched with the recorder was employed to analyze the heart rate variability of the parachutists when they left from their encampment,arriving in airport and in the plane.Results As compared with the first parachute,the indices of high frequency(HF and normalized high frequency(HFNU of the new parachutists measured when they were at their encampment were higher than that of their fourth and seventh parachute(P 0.05.The index of HFNU of the seventh parachute increased significantly compared with that of the first parachute when these recruits were in the plane(P < 0.05.In contrast,the indices of LFNU and LF/HF declined in the seventh parachute compared with that in the first parachute,and even lower than that in the fourth parachute(P < 0.05.Conclusion With an increase in frequency of parachute,mental stress level of the new parachutists declines significantly when they are at their encampment and in the plane.But no evident change in stress level has been detected when they are at the airport.

Liang-en CHEN

2011-04-01

324

Do physiological and pathological stresses produce different changes in heart rate variability?  

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Full Text Available Although physiological (e.g. exercise and pathological (e.g. infection stress affecting the cardiovascular system have both been documented to be associated with a reduction in overall heart rate variability (HRV, it remains unclear if loss of HRV is ubiquitously similar across different domains of variability analysis or if distinct patterns of altered HRV exist depending on the stressor. Using Continuous Individualized Multiorgan Variability Analysis (CIMVATM software, heart rate (HR and four selected measures of variability were measured over time (windowed analysis from two datasets, a set (n=13 of patients who developed systemic infection (i.e. sepsis after bone marrow transplant, and a matched set of healthy subjects undergoing physical exercise under controlled conditions. HR and the four HRV measures showed similar trends in both sepsis and exercise. The comparison through Wilcoxon sign-rank test of the levels of variability at baseline and during the stress (i.e. exercise or after days of sepsis development showed similar changes, except for LF/HF, ratio of power at low and high frequencies (associated with sympathovagal modulation, which was affected by exercise but did not show any change during sepsis. Furthermore, HRV measures during sepsis showed a lower level of correlation with each other, as compared to HRV during exercise. In conclusion, this exploratory study highlights similar responses during both exercise and infection, with differences in terms of correlation and inter-subject fluctuations, whose physiologic significance merits further investigation.

GeoffreyGreen

2013-07-01

325

The utility of heart rate recovery to predict right ventricular systolic dysfunction in patients with obesity  

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Full Text Available Objective: Obesity is a nutritional disorder, which is associated with impaired left and right ventricular function. Impaired heart rate recovery (HRR following a treadmill exercise test is an indicator of cardiovascular mortality. We investigated the utility of impaired HRR on the tissue Doppler imaging (TDI echocardiographic estimates of left and right ventricular function in an obese/overweight cohort. Methods: Eighty consecutive patients with body mass index >27 kg/m2 were evaluated for their post exercise HRR in this cross-sectional study. The results were compared with the tissue Doppler and conventional echocardiographic findings of the same cohort. Tricuspid annular TDI peak systolic velocities (RVs were evaluated with receiver operating characteristic (ROC analysis to predict the insufficient heart rate recovery (18/min or less. Logistic regression analysis was used to identify the independent predictors of significant right ventricular systolic dysfunction (RVs 10cm/sec. Impaired HRR and septum TDI late diastolic velocity were found as the independent predictors of right ventricular systolic function (RVs<10cm/sec by logistic regression analysis.Conclusion: Post-exercise first minute impaired HRR is associated with right ventricular systolic dysfunction in obese patients. Both HRR and right ventricular systolic function correlate well with the exercise distance and METs. Obese patients with impaired HRR should be evaluated with echocardiography to assess their right ventricular systolic function.

Yelda Ba?aran

2009-12-01

326

Altered heart rate and blood pressure variability in mice lacking the Mas protooncogene  

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Full Text Available Heart rate variability is a relevant predictor of cardiovascular risk in humans. A significant genetic influence on heart rate variability is suggested, although the genes involved are ill-defined. The Mas-protooncogene encodes a G-protein-coupled receptor with seven transmembrane domains highly expressed in testis and brain. Since this receptor is supposed to interact with the signaling of angiotensin II, which is an important regulator of cardiovascular homeostasis, heart rate and blood pressure were analyzed in Mas-deficient mice. Using a femoral catheter the blood pressure of mice was measured for a period of 30 min and 250 data values per second were recorded. The mean values and range of heart rate and blood pressure were then calculated. Neither heart rate nor blood pressure were significantly different between knockout mice and controls. However, high resolution recording of these parameters and analysis of the data by non-linear dynamics revealed significant alterations in cardiovascular variability in Mas-deficient animals. In particular, females showed a strong reduction of heart rate variability. Furthermore, the data showed an increased sympathetic tone in knockout animals of both genders. The marked alterations detected in Mas-deficient mice of both genders suggest that the Mas-protooncogene is an important determinant of heart rate and blood pressure variability.

Walther T.

2000-01-01

327

Real-time Continuous Assessment Method for Mental and Physiological Condition using Heart Rate Variability  

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It is necessary to monitor the daily health condition for preventing stress syndrome. In this study, it was proposed the method assessing the mental and physiological condition, such as the work stress or the relaxation, using heart rate variability at real time and continuously. The instantanuous heart rate (HR), and the ratio of the number of extreme points (NEP) and the number of heart beats were calculated for assessing mental and physiological condition. In this method, 20 beats heart rate were used to calculate these indexes. These were calculated in one beat interval. Three conditions, which are sitting rest, performing mental arithmetic and watching relaxation movie, were assessed using our proposed algorithm. The assessment accuracies were 71.9% and 55.8%, when performing mental arithmetic and watching relaxation movie respectively. In this method, the mental and physiological condition was assessed using only 20 regressive heart beats, so this method is considered as the real time assessment method.

Yoshida, Yutaka; Yokoyama, Kiyoko; Ishii, Naohiro

328

Temporary decrease in heart rate in Lyme carditis during treatment with antibiotics.  

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Lyme disease is a recognised cause of atrioventricular block. In most cases the conduction disturbances are reversed by treatment with antibiotics. A 44 year old man with third degree atrioventricular block in Lyme carditis had a temporary decrease in heart rate during resolution of the heart block two days after treatment with antibiotics was started.

Dam, E. P.; Jonker, D. R.; Hoorntje, J. C.

1996-01-01

329

Discrete Scale Invariance in the Cascade Heart Rate Variability Of Healthy Humans  

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Evidence of discrete scale invariance (DSI) in daytime healthy heart rate variability (HRV) is presented based on the log-periodic power law scaling of the heart beat interval increment. Our analysis suggests multiple DSI groups and a dynamic cascading process. A cascade model is presented to simulate such a property.

Lin, D C

2004-01-01

330

Atrial fibrillation in heart failure: drug therapies for rate and rhythm control.  

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Pharmacological treatment of atrial fibrillation in the context of heart failure poses numerous challenges. Management decisions are limited by contraindications to several drugs and the paucity of robust clinical trials that provide evidence-based guidance. This review proposes a structured action plan for managing atrial fibrillation coexisting with heart failure that considers published clinical guidelines and integrates recent data derived from substudies of randomized trials, including the atrial fibrillation and congestive heart failure (AF-CHF) trial. Areas of uncertainty, such as target heart rates in atrial fibrillation and upstream therapies, are also discussed. PMID:23690262

Tadros, Rafik; Khairy, Paul; Rouleau, Jean L; Talajic, Mario; Guerra, Peter G; Roy, Denis

2014-05-01

331

AKAP10 (I646V) Functional Polymorphism Predicts Heart Rate and Heart Rate Variability in Apparently Healthy, Middle-aged European-Americans  

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Previous evidence suggests that the dual-specific A kinase-anchoring protein 2 functional polymorphism (AKAP10 (A/G) I646V) influences heart rate (HR) and heart rate variability (HRV) in mice and humans (N=122) with cardiovascular disease. Here, we asked whether this AKAP10 variant predicts HR and HRV in large sample of healthy humans. Resting HR and short-term time and frequency domain measures of HRV (5 min during paced and unpaced respiration conditions) were assessed in a U.S. community s...

Neumann, Serina A.; Tingley, Whittemore G.; Conklin, Bruce R.; Shrader, Catherine J.; Peet, Eloise; Muldoon, Matthew F.; Jennings, J. Richard; Ferrell, Robert E.; Manuck, Stephen B.

2009-01-01

332

The influence of challenging objects and horse-rider matching on heart rate, heart rate variability and behavioural score in riding horses  

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A good horse-rider 'match' is important in the context of equine welfare. To quantify the influence of repetition and horse-rider matching on the stress of horses encountering challenging objects, 16 Warmblood horses were ridden in a test-setting on three occasions. On each occasion the horse was ridden by a different rider and was challenged by three objects (A-C). Heart rate (HR), heart rate variability (HRV) of horse and rider, and behaviour score (BS) of the horse were obtained for each o...

Munsters, C.; Visser, E. K.; Broek, J.; Sloet Oldruitenborgh-oosterbaan, M. M.

2012-01-01

333

Age differences in heart rate patterns during concentration in a precision sport: implications for attentional functioning.  

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Highly skilled young (M = 29.5 years) and older (M = 50.0 years) miniature golf players were observed in relaxed training and high-arousal competition rounds. Motor performance (number of shots), subjective ratings of anxiety, and heart rate were registered. Results showed a similar increase of arousal from training to competition for both age groups. However, the older group deteriorated in motor performance from training to competition, whereas the younger group played equally well on both occasions. Results from continuous measurement of heart rate indicated a deceleration during the concentration phases among the younger players, and the magnitude of deceleration increased from training to competition. In contrast, heart rate accelerated during training among the older players, the magnitude of the heart rate change decreasing from training to competition. This evidence suggests that the deterioration in motor performance observed in older players in stressful competitive activity may be due to age-related changes in attentional functioning. PMID:2715589

Molander, B; Bäckman, L

1989-05-01

334

Ivabradine as a heart rate-lowering agent in a patient with end-stage renal failure after heart transplantation.  

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A 56 year-old woman with a transplanted heart, with arterial hypertension and chronic pulmonary obstructive disease, was hospitalised because of palpitations, dyspnea, chest pain and oedema. After cyclosporine treatment she was diagnosed with renal failure, which was treated by hemodialysis. Heart rate (HR) at admission was 100, mean HR in 24-hour Holter monitoring was 106 bpm. Ivabradine was added to the treatment. The dose of 2.5 mg bid was doubled after three days. Mean HR in control Holter monitoring was 81. Ivabradine was well tolerated in this patient. The clinical benefits were observed soon after application and maintained during the follow-up. PMID:20806202

Kurpesa, Ma?gorzata; Trzos, Ewa; Wierzbowska-Drabik, Karina; Rechci?ski, Tomasz

2010-06-01

335

Ivabradine, a novel heart rate slower: Is it a sword of double blades in patients with idiopathic dilated cardiomyopathy?  

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Full Text Available Objective: To prospectively assess the safety and efficacy of ivabradine in patients with idiopathic dilated cardiomyopathy.Methods: We included 35 patients with idiopathic dilated cardiomyopathy with an ejection fraction (EF 70 beats/min despite optimal medical therapy, according to the international guidelines in this prospective, non-randomized, single-arm, open-label safety study. Ivabradine was used as an add-on therapy to the maximally tolerated b-blocker in an increasing titrated dose till a target dose of 15 mg/day or resting heart rate of 60 beats/min for 3 months. During follow-up period the safety, patient tolerance and efficacy of this drug were assessed. All patients underwent 12-lead resting electrocardiography and Holter monitoring at inclusion and after 3 months. Statistical analysis was accomplished using paired t-test and Pearson correlation analysis.Results: We found a significant reduction in the resting heart rate by a mean of 25.9±9.4%, without a significant change of blood pressure. There was no prolongation of PR, QTc or QRS durations. Ventricular ectopic activity showed significant reduction (p<0.001. There was a significant correlation between the resting heart rate, NYHA and left ventricular ejection fraction (p<0.001 for both. One patient developed photopsia and decompensation was observed in another patient. Conclusion: Ivabradine is a safe and effective drug in reducing resting heart rate, improving NYHA functional class without undesirable effects on conduction parameters or ectopic activity.

Mona Rayan

2011-08-01

336

Music close to one's heart: heart rate variability with music, diagnostic with e-bra and smartphone  

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Music is a powerful elicitor of emotions. Emotions evoked by music, through autonomic correlates have been shown to cause significant modulation of parameters like heart rate and blood pressure. Consequently, Heart Rate Variability (HRV) analysis can be a powerful tool to explore evidence based therapeutic functions of music and conduct empirical studies on effect of musical emotion on heart function. However, there are limitations with current studies. HRV analysis has produced variable results to different emotions evoked via music, owing to variability in the methodology and the nature of music chosen. Therefore, a pragmatic understanding of HRV correlates of musical emotion in individuals listening to specifically chosen music whilst carrying out day to day routine activities is needed. In the present study, we aim to study HRV as a single case study, using an e-bra with nano-sensors to record heart rate in real time. The e-bra developed previously, has several salient features that make it conducive for this study- fully integrated garment, dry electrodes for easy use and unrestricted mobility. The study considers two experimental conditions:- First, HRV will be recorded when there is no music in the background and second, when music chosen by the researcher and by the subject is playing in the background.

Hegde, Shantala; Kumar, Prashanth S.; Rai, Pratyush; Mathur, Gyanesh N.; Varadan, Vijay K.

2012-03-01

337

Happiness and heart rate response: a case of fan services at japanese professional baseball games  

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Full Text Available The aim of this study was to develop a method for predicting the psychological states of spectators watching professional baseball games at a stadium. This method includes a real time measurement of instantaneous heart rate (i.e., the inverse of the RR interval without preventing the subject from watching the game and a mathematical procedure used to predict moment by moment psychological states by correlating the degree of a psychological state with the strength of heart rate response, defined as the mean deviation of heart rate variability from a linear regression line from 5 sec before to 25 sec after an event during a baseball game. We recorded the instantaneous heart rates of 10 subjects (total of 27 cases while they watched Japanese professional baseball games at a stadium and had them subjectively rate the degree of their psychological states in an after-event interview. We identified three psychological states (happiness, excitement, and vigor whose strength can be predicted from the strength of heart rate response. Analysis of the measured data clarified that heart rate response had a significant correlation with the subjective rating of the intensity of happiness (r = 0.56, p < 0.0001, vigor (r = 0.55, p < 0.0001, and excitement (r = 0.49, p < 0.0001.

Muneo Kitajima

2011-03-01

338

ROC Analysis and a Realistic Model of Heart Rate Variability  

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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 \\sigma_{wav}(m), a multiresolution-based analysis measure, is found to be superior to two commonly used measures of cardiac dysfunction when the two classes of patients cannot be complete...

Thurner, Stefan; Feurstein, Markus C.; Teich, Malvin C.

1998-01-01

339

The Influence of Neuromuscular Electrical Stimulation on the Heart Rate Variability in Healthy Subjects  

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[Purpose] The purpose of this study was to examine the effect of neuromuscular electrical stimulation (NMES) on heart rate variability (HRV). [Subjects and Methods] Ten healthy subjects participated in the study. All subjects received NMES with a pulse duration of 300 us and frequency of 30?Hz at the vastus lateralis and vastus medialis for 15 minutes. The stimulation intensity was adjusted in the range of 20 to 30 mA. HRV using a pulse oximeter was measured in the sitting position before and after NMES. [Results] After the NMES, all HRV data slightly increased, but there was no significance between before and after data. [Conclusion] We suggest that strengthening exercises using NMES may be undertaken safely.

Kang, Jong Ho; Hyong, In Hyouk

2014-01-01

340

Children's heart rate variability as stress indicator: association with reported stress and cortisol.  

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Stress is a complex phenomenon coordinated by two main neural systems: the hypothalamic-pituitary-adrenal system with cortisol as classical stress biomarker and the autonomic nervous system with heart rate variability (HRV) as recently suggested stress marker. To test low HRV (5 minute measurements) as stress indicator in young children (5-10 y), associations with self-reported chronic stress aspects (events, emotions and problems) (N=334) and salivary cortisol (N=293) were performed. Peer problems, anger, anxiety and sadness were associated with lower root mean square of successive differences (RMSSD) and high frequency power (i.e. lower parasympathetic activity). Anxiety and anger were also related to a higher low frequency to high frequency ratio. Using multilevel modelling, higher cortisol levels, a larger cortisol awakening response and steeper diurnal decline were also associated with these HRV patterns of lower parasympathetic activity. Conclusion: Low HRV (lower parasympathetic activity) might serve as stress indicator in children. PMID:24007813

Michels, Nathalie; Sioen, Isabelle; Clays, Els; De Buyzere, Marc; Ahrens, Wolfgang; Huybrechts, Inge; Vanaelst, Barbara; De Henauw, Stefaan

2013-10-01

 
 
 
 
341

Prospective and retrospective ECG-gating for CT coronary angiography perform similarly accurate at low heart rates  

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Objective: To compare, in patients with suspicion of coronary artery disease (CAD) and low heart rates, image quality, diagnostic performance, and radiation dose values of prospectively and retrospectively electrocardiography (ECG)-gated dual-source computed tomography coronary angiography (CTCA) for the diagnosis of significant coronary stenoses. Materials and methods: Two-hundred consecutive patients with heart rates ?70 bpm were retrospectively enrolled; 100 patients undergoing prospectively ECG-gated CTCA (group 1) and 100 patients undergoing retrospectively-gated CTCA (group 2). Coronary artery segments were assessed for image quality and significant luminal diameter narrowing. Sensitivity, specificity, positive predictive values (PPV), negative predictive values (NPV), and accuracy of both CTCA groups were determined using conventional catheter angiography (CCA) as reference standard. Radiation dose values were calculated. Results: Both groups were comparable regarding gender, body weight, cardiovascular risk profile, severity of CAD, mean heart rate, heart rate variability, and Agatston score (all p > 0.05). There was no significant difference in the rate of non-assessable coronary segments between group 1 (1.6%, 24/1404) and group 2 (1.4%, 19/1385; p = 0.77); non-diagnostic image quality was significantly (p 0.05). Mean effective radiation dose of prospectively ECG-gated CTCA (2.2 ± 0.4 mSv) was significantly (p < 0.0001) smaller than that of retrospectively ECG-gated CTCA (8.1 ± 0.6 mSv). Conclusion: Prospectively ECG-gated CTCA yields similar image quality, performs as accurately as retrospectively ECG-gated CTCA in patients having heart rates ?70 bpm while being associated with a lower mean effective radiation dose.

2011-07-01

342

The Correlates of Body Composition with Heart Rate Recovery after Step Test: An Exploratory Study of Malaysian Adolescents  

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Background In adults, heart rate recovery is a predictor of mortality, while in adolescents it is associated with cardio-metabolic risk factors. The aim of this study was to examine the relationship between body composition measures and heart rate recovery (HRR) after step test in Malaysian secondary school students. Methods In the Malaysian Health and Adolescents Longitudinal Research Team (MyHEART) study, 1071 healthy secondary school students, aged 13 years old, participated in the step test. Parameters for body composition measures were body mass index z-score, body fat percentage, waist circumference, and waist height ratio. The step test was conducted by using a modified Harvard step test. Heart rate recovery of 1 minute (HRR1min) and heart rate recovery of 2 minutes (HRR2min) were calculated by the difference between the peak pulse rate during exercise and the resting pulse rate at 1 and 2 minutes, respectively. Analysis was done separately based on gender. Pearson correlation analysis was used to determine the association between the HRR parameters with body composition measures, while multiple regression analysis was used to determine which body composition measures was the strongest predictor for HRR. Results For both gender groups, all body composition measures were inversely correlated with HRR1min. In girls, all body composition measures were inversely correlated with HRR2min, while in boys all body composition measures, except BMI z-score, were associated with HRR2min. In multiple regression, only waist circumference was inversely associated with HRR2min (p=0.024) in boys, while in girls it was body fat percentage for HRR2min (p=0.008). Conclusion There was an inverse association between body composition measurements and HRR among apparently healthy adolescents. Therefore, it is important to identify cardio-metabolic risk factors in adolescent as an early prevention of consequent adulthood morbidity. This reiterates the importance of healthy living which should start from young.

Abu Hanifah, Redzal; Mohamed, Mohd. Nahar Azmi; Jaafar, Zulkarnain; Abdul Mohsein, Nabilla Al-Sadat; Jalaludin, Muhammad Yazid; Abdul Majid, Hazreen; Murray, Liam; Cantwell, Marie; Su, Tin Tin

2013-01-01

343

Prospective and retrospective ECG-gating for CT coronary angiography perform similarly accurate at low heart rates  

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Objective: To compare, in patients with suspicion of coronary artery disease (CAD) and low heart rates, image quality, diagnostic performance, and radiation dose values of prospectively and retrospectively electrocardiography (ECG)-gated dual-source computed tomography coronary angiography (CTCA) for the diagnosis of significant coronary stenoses. Materials and methods: Two-hundred consecutive patients with heart rates {<=}70 bpm were retrospectively enrolled; 100 patients undergoing prospectively ECG-gated CTCA (group 1) and 100 patients undergoing retrospectively-gated CTCA (group 2). Coronary artery segments were assessed for image quality and significant luminal diameter narrowing. Sensitivity, specificity, positive predictive values (PPV), negative predictive values (NPV), and accuracy of both CTCA groups were determined using conventional catheter angiography (CCA) as reference standard. Radiation dose values were calculated. Results: Both groups were comparable regarding gender, body weight, cardiovascular risk profile, severity of CAD, mean heart rate, heart rate variability, and Agatston score (all p > 0.05). There was no significant difference in the rate of non-assessable coronary segments between group 1 (1.6%, 24/1404) and group 2 (1.4%, 19/1385; p = 0.77); non-diagnostic image quality was significantly (p < 0.001) more often attributed to stair step artifacts in group 1. Segment-based sensitivity, specificity, PPV, NPV, and accuracy were 98%, 98%, 88%, 100%, and 100% among group 1; 96%, 99%, 90%, 100%, and 98% among group 2, respectively. Parameters of diagnostic performance were similar (all p > 0.05). Mean effective radiation dose of prospectively ECG-gated CTCA (2.2 {+-} 0.4 mSv) was significantly (p < 0.0001) smaller than that of retrospectively ECG-gated CTCA (8.1 {+-} 0.6 mSv). Conclusion: Prospectively ECG-gated CTCA yields similar image quality, performs as accurately as retrospectively ECG-gated CTCA in patients having heart rates {<=}70 bpm while being associated with a lower mean effective radiation dose.

Stolzmann, Paul, E-mail: paul.stolzmann@usz.ch [Institute of Diagnostic Radiology, University Hospital Zurich, Raemistrasse 100, 8091 Zurich (Switzerland); Goetti, Robert; Baumueller, Stephan [Institute of Diagnostic Radiology, University Hospital Zurich, Raemistrasse 100, 8091 Zurich (Switzerland); Plass, Andre; Falk, Volkmar [Clinic for Cardiovascular Surgery, University Hospital Zurich (Switzerland); Scheffel, Hans; Feuchtner, Gudrun; Marincek, Borut [Institute of Diagnostic Radiology, University Hospital Zurich, Raemistrasse 100, 8091 Zurich (Switzerland); Alkadhi, Hatem [Institute of Diagnostic Radiology, University Hospital Zurich, Raemistrasse 100, 8091 Zurich (Switzerland); Cardiac MR PET CT Program, Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States); Leschka, Sebastian [Institute of Diagnostic Radiology, University Hospital Zurich, Raemistrasse 100, 8091 Zurich (Switzerland)

2011-07-15

344

Aquatraining - Effects on selected bloodparameters and on the heart-rate variability of horses  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The objectives of the present investigation were to investigate the effects of Aquatraining with horses on selected blood parameters and on heart rate variability to determine the degree of burden of this training-method.

2010-01-01

345

Joint Symbolic Dynamics Analysis of Heart Rate and Systolic Blood Pressure Interactions in Dilated Cardiomyopathy.  

Science.gov (United States)

The dilated cardiomyopathy (DCM) induces important changes in the autonomic control. Measures of heart rate (HR) variability and systolic blood pressure (SP) variability are sensitive to those changes. The interactions between HR and SP are rather complex...

A. Voss M. Baumert

2001-01-01

346

PARTICULATE MATTER AND HEART RATE VARIABILITY AMONG ELDERLY RETIREES: THE BALTIMORE 1998 PM STUDY  

Science.gov (United States)

This study investigates the reported relationship between ambient fine particle pollution and impaired cardiac autonomic control in the elderly. Heart rate variability (HRV) among 56 elderly (mean age 82) nonsmoking residents of a retirement center in Baltimore County, Maryland,...

347

Effect of pre operative heart rate on post spinal hypotension in obsteric patients  

International Nuclear Information System (INIS)

The purpose of the study was to determine the association between of preoperative heart rate and post spinal hypotension in women undergoing cesarean section, Two hundred patients undergoing caesarean were included in the study selected on non probability convenience sampling technique, The patients were divided into two groups depending upon their pre operative heart rate. Spinal anesthesia was administered and number of patients developing hypotension was noted. Among 200 patients, who were included in the study; 112 were placed in group A and 88 were placed in group B depending on mean heart rate of 90 beats per minute or less or 91 beats per minute or more respectively. In group A 14 (11.86%) patients developed hypotension where as in group B 28 (31,82%) patients developed hypotension. Pre operative heart rate is significantly associated with post spinal hypotension in obstetric patients undergoing cesarean section. (author)

2010-06-01

348

Using Complexity Metrics With R-R Intervals and BPM Heart Rate Measures  

DEFF Research Database (Denmark)

Lately, growing attention in the health sciences has been paid to the dynamics of heart rate as indicator of impending failures and for prognoses. Likewise, in social and cognitive sciences, heart rate is increasingly employed as a measure of arousal, emotional engagement and as a marker 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 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-concept, we employ a simple rest-exercise-rest task and show that non-linear statistics â?? fractal (DFA) and recurrence (RQA) analyses â?? 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 dynamics, but their power to do so critically depends on the type data that is employed: While R-R intervals are very susceptible to nonlinear analyses, the success of nonlinear methods for BPM data critically depends on their construction. Generally, â??oversampledâ?? BPM time-series can be recommended as they retain most of the information about nonlinear aspects of heart beat dynamics.

Wallot, Sebastian; Fusaroli, Riccardo

2013-01-01

349

Using Complexity Metrics With R-R Intervals and BPM Heart Rate Measures  

Directory of Open Access Journals (Sweden)

Full Text Available Lately, growing attention in the health sciences has been paid to the dynamics of heart rate as indicator of impending failures and for prognoses. Likewise, in social and cognitive sciences, heart rate is increasingly employed as a measure of arousal, emotional engagement and as a marker 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 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-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 dynamics, but their power to do so critically depends on the type data that is employed: While R-R intervals are very susceptible to nonlinear analyses, the success of nonlinear methods for BPM data critically depends on their construction. Generally, ‘oversampled’ BPM time-series can be recommended as they retain most of the information about nonlinear aspects of heart beat dynamics.

SebastianWallot

2013-08-01

350

Time Domain Measures of Heart Rate Variability to Assess Autonomic Dysfunction In Irritable Bowel Syndrome  

Digital Repository Infrastructure Vision for European Research (DRIVER)

AbstractBackground: Autonomic nerve function impairment is related to development of Irritable Bowel Syndrome (IBS). Time domain measures of Heart rate variability (HRV) is a useful tool to measure autonomic nerve function activity.Objective: To assess autonomic nerve function activity by time domain measures of heart rate variability in patients with Irritable Bowel Syndrome.Methods: This cross sectional study was conducted in the Department of Physiology, Bangabandhu Sheikh Mujib Medical Un...

2012-01-01

351

Assessment of short-term prognosis by sinus heart rate turbulence in patients with unstable angina  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The aim of this study was to explore the correlation between sinus heart rate turbulence (HRT) and short-term prognosis in patients with unstable angina (UA). Seventy-five patients with UA received Holter monitoring for 24 h, within 48 h of hospitalization to obtain parameters of HRT, including turbulence onset (TO) and turbulence slope (TS), as well as parameters of heart rate variability (HRV), including standard deviation of all NN intervals (SDNN) and average R-R interval. The left ventri...

2013-01-01

352

Heart Rate Variability Responses of a Preterm Infant to Kangaroo Care  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A 35-week old preterm infant's behavior was fussy and restless in the open crib, but he calmed and fell asleep immediately on being placed skin-to-skin on his mother's chest. Heart rate variability (HRV), a noninvasive method to assess the autonomic nervous system's influence on heart rate, was increased with fussy behavior in the open crib and decreased with sleep during kangaroo care (KC). KC produced changes in behavior and HRV that are illustrative of decreasing stress.

Mccain, Gail C.; Ludington-hoe, Susan M.; Swinth, Joan Y.; Hadeed, Anthony J.

2005-01-01

353

Dynamic Cardiovagal Response to Motion Sickness: A Point-Process Heart Rate Variability Study  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A visual display of stripes was used to examine cardio-vagal response to motion sickness. Heart rate variability (HRV) was investigated using dynamic methods to discern instantaneous fluctuations in reaction to stimulus and perception-based events. A novel point process adaptive recursive algorithm was applied to the R-R series to compute instantaneous heart rate, HRV, and high frequency (HF) power as a marker of vagal activity. Results show interesting dynamic trends in each of the considere...

2009-01-01

354

Dynamic cardiovagal response to motion sickness: A point-process heart rate variability study  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A visual display of stripes was used to examine cardiovagal response to motion sickness. Heart rate variability (HRV) was investigated using dynamic methods to discern instantaneous fluctuations in reaction to stimulus and perception-based events. A novel point process adaptive recursive algorithm was applied to the R-R series to compute instantaneous heart rate, HRV, and high frequency (HF) power as a marker of vagal activity. Results show interesting dynamic trends in each of the considered...

2009-01-01

355

Happiness and heart rate response: a case of fan services at japanese professional baseball games  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The aim of this study was to develop a method for predicting the psychological states of spectators watching professional baseball games at a stadium. This method includes a real time measurement of instantaneous heart rate (i.e., the inverse of the RR interval) without preventing the subject from watching the game and a mathematical procedure used to predict moment by moment psychological states by correlating the degree of a psychological state with the strength of heart rate response, defi...

Kohzoh Yoshino; Sayaka Matsumoto; Eiichi Someya; Muneo Kitajima

2011-01-01

356

Correlation between Mortality of Prehospital Trauma Patients and Their Heart Rate Complexity  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Recently, nonlinear analysis of R-to-R interval (RRI) in heart rate has brought research attention in medicine to improve predictive accuracy of medication in severely injured patients. It seems conventional vital signs information such as heart rate and blood pressure to identify critically injured patients eventually replaced by heartrate complexity (HRC) analysis to the electrocardiogram (ECG) of patients in trauma centers. In this respect, different nonlinear analysis tools such as; power...

Gholamhussian Erjaee; Ali Foroutan; Sara Keshtkar; Pegah ShojaMozafar; Alham Benabas

2012-01-01

357

Non-linear and scale-invariant analysis of the Heart Rate Variability  

CERN Document Server

Human heart rate fluctuates in a complex and non-stationary manner. Elaborating efficient and adequate tools for the analysis of such signals has been a great challenge for the researchers during last decades. Here, an overview of the main research results in this field is given. The following question are addressed: (a) what are the intrinsic features of the heart rate variability signal; (b) what are the most promising non-linear measures, bearing in mind clinical diagnostic and prognostic applications.

Kalda, J; Vainu, M; Laan, M

2003-01-01

358

Decreased heart rate variability in survivors of sudden cardiac death not associated with coronary artery disease.  

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BACKGROUND--Although heart rate variability has already been studied in survivors of sudden cardiac death secondary to coronary artery disease, an assessment of heart rate variability in survivors of sudden cardiac death not associated with coronary artery disease has not been made. METHODS--10 patients with aborted sudden cardiac death not associated with coronary artery disease (seven patients with primary ventricular fibrillation and three with unclassified mild cardiomyopathy) underwent t...

Fei, L.; Anderson, M. H.; Katritsis, D.; Sneddon, J.; Statters, D. J.; Malik, M.; Camm, A. J.

1994-01-01

359

Learned cardiac control with heart rate biofeedback transfers to emotional reactions  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Emotions involve subjective feelings, action tendencies and physiological reactions. Earlier findings suggest that biofeedback might provide a way to regulate the physiological components of emotions. The present study investigates if learned heart rate regulation with biofeedback transfers to emotional situations without biofeedback. First, participants learned to decrease heart rate using biofeedback. Then, inter-individual differences in the acquired skill predicted how well they could dec...

Peira, Nathalie; Pourtois, Gilles; Fredrikson, M.

2013-01-01

360

The Effects of Meperidine Analgesia during Labor on Fetal Heart Rate  

Digital Repository Infrastructure Vision for European Research (DRIVER)

To estimate the effects of intramuscular meperidine analgesia on fetal heart rate (FHR) patterns compared with placebo. In a prospective randomized study, 150 healthy women with singleton term pregnancy requesting analgesia during active labor were planned to receive either intramuscular meperidin 50 mg (meperidin group) or normal saline (control group) when they requested analgesia. Fetal heart rate patterns occurring within 40 minutes of initiation of labor analgesia were retrospectively re...

2009-01-01

 
 
 
 
361

Heart Rate Characteristics: Physiomarkers for Detection of Late-Onset Neonatal Sepsis  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Early detection of late onset neonatal sepsis, prior to obvious and potentially catastrophic clinical signs, is an important goal in neonatal medicine. Sepsis causes a well-known series of physiologic changes including abnormalities of blood pressure, respiration, temperature, and heart rate, and less well-known changes in heart rate variability. While vital signs are frequently or continuously monitored in NICU patients, changes in these parameters are subtle in the early phase of sepsis and...

Fairchild, Karen D.; O Shea, T. Michael

2010-01-01

362

Does fractality in heart rate variability indicate the development of fetal neural processes?  

Science.gov (United States)

By using an improved detrended fluctuation analysis we studied the scaling behaviour of 53 long-term series of fetal heart rate fluctuations. Our results suggest that fractality begins to arise around 24 weeks of normal human gestation and that this condition, showing some additional developments, seems to be preserved during gestation. This may provide new evidence of a role played by cortical-to-subcortical pathways in the long-term fractal nature of heart rate variability data.

Echeverría, J. C.; Woolfson, M. S.; Crowe, J. A.; Hayes-Gill, B. R.; Piéri, Jean F.; Spencer, C. J.; James, D. K.

2004-10-01

363

Variations in circadian heart rate in psychiatric disorders: theoretical and practical implications  

Digital Repository Infrastructure Vision for European Research (DRIVER)

HG Stampfer,1 SB Dimmitt2 1School of Psychiatry and Clinical Neurosciences, University of Western Australia, 2School of Medicine and Pharmacology, University of Western Australia, Crawley, WA, AustraliaBackground: Data are presented to demonstrate dimensions of variation in circadian heart rate in patients under treatment for a psychiatric disorder and to comment on their clinical relevance.Method: Serial recordings of 24-hour heart rates were obtained from individuals under treatment fo...

Hg, Stampfer; Sb, Dimmitt

2013-01-01

364

Heart rate variability and cardiac autonomic function in men with chronic alcohol dependence.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Cardiac autonomic function was studied in 23 alcohol dependent men by standard tests of autonomic function and measurement of 24 hour heart rate variability. In all there was peripheral or central nervous system damage or both. Standard tests of autonomic function showed vagal neuropathy in seven. The remainder had normal autonomic function tests. Twenty four hour heart rate variability was measured as the standard deviation of the successive differences between RR intervals from an ambulator...

Malpas, S. C.; Whiteside, E. A.; Maling, T. J.

1991-01-01

365

Blood pressure, heart rate and lipids in professional handball and water polo players  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Introduction: Blood pressure, heart rate and lipoprotein lipids are affected by family history, obesity, diet, smoking and physical activity habits. The aim of this paper was to estimate the values of blood pressure and heart rate in professional handball and water polo players before and after training and submaximal exercise test and to analyze the lipid state in these professional athletes in comparison with people who have never been in sports. Material and methods The investigation inclu...

Jovanovi? Jovica; Jovanovi? Milan

2005-01-01

366

Nonlinear heart rate dynamics: Circadian profile and influence of age and gender  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Heart rate variability (HRV) is used as a marker of autonomic modulation of heart rate. Nonlinear HRV parameters providing information about the scaling behaviour or the complexity of the cardiac system were included. In addition, the chaotic behaviour was quantified by means of the recently developed numerical noise titration technique. 24h Holter recordings of a large healthy population (N=276, 141 males, 18-71 years of age) were available. The goal was to investigate the influence of gende...

2012-01-01

367

Heart rate recovery does not predict endothelial function in obese women  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The purpose of the present study was to examine the relationship between heart rate recovery (HRREC) and endothelial function in obese women with the metabolic syndrome. The metabolic syndrome has been associated with increased cardiometabolic risk including endothelial dysfunction. However, measurement of endothelial function via flow-mediated dilation (FMD) requires expensive equipment and qualified medical personnel, and therefore may be impractical in some healthcare settings. Heart rate ...

Swift, Damon L.; Irving, Brian A.; Brock, David W.; Davis, Christopher K.; Barrett, Eugene J.; Gaesser, Glenn A.; Weltman, Arthur

2007-01-01

368

Variation in heart rate influences the assessment of transient ischemic dilation in myocardial perfusion scintigraphy  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Background Transient arrhythmias can affect transient ischemic dilation (TID) ratios. This study was initiated to evaluate the frequency and effect of normal heart rate change on TID measures in routine clinical practice. Methods Consecutive patients undergoing stress/rest sestamibi gated myocardial perfusion scintigraphy were studied (N = 407). Heart rate at the time of stress and rest imaging were recorded. TID ratios were analyzed in relation to abso...

Leslie William D; Levin Daniel P; Demeter Sandor J

2007-01-01

369

Can power spectral analysis of heart rate variability identify a high risk subgroup of congestive heart failure patients with excessive sympathetic activation? A pilot study before and after heart transplantation.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

BACKGROUND AND OBJECTIVES--Autonomic dysfunction seems to be involved in the progression and prognosis of severe congestive heart failure. Parasympathetic activity can still be abnormal 4-8 weeks after haemodynamic improvement by heart transplantation. To identify patients in heart failure with a more pronounced neural derangement and to analyse the changes in sympathetic and parasympathetic activity soon after heart transplantation, spectral indices of heart rate variability were assessed in...

Mortara, A.; La Rovere, M. T.; Signorini, M. G.; Pantaleo, P.; Pinna, G.; Martinelli, L.; Ceconi, C.; Cerutti, S.; Tavazzi, L.

1994-01-01

370

New descriptors of T-wave morphology are independent of heart rate  

DEFF Research Database (Denmark)

T-wave morphology descriptors are sensitive to drug-induced changes and may be a useful addition to the QT interval in cardiac safety trials. Intrasubject heart rate dependence of T-wave morphology was investigated in a sample of 39 healthy individuals. Ten-second electrocardiograms were obtained from daytime Holter recordings. Duration parameters (QT, ToTe, TpTe, and others), a number of basic T-wave morphology parameters (amplitude, area, and others) as well as advanced morphology descriptors (asymmetry, flatness, and others) were measured automatically. Heart rate dependence was examined by means of analysis of covariance. The results showed clear heart rate dependence for the QT interval (R(2) = 0.53-0.57) and a moderate degree of heart rate dependence for the basic morphology parameters (amplitude, area, and others) (R(2) = 0.17-0.42). Both the advanced T-wave descriptors (asymmetry, flatness, and others), ToTe intervals and TpTe intervals, were practically independent of heart rate (R(2) = 0-0.08), making heart rate correction unnecessary for these parameters.

Andersen, Mads Peter; Xue, Joel Q

2011-01-01

371

The effects of heart rate and aiming time on performance in Turkish National Archery Team  

Directory of Open Access Journals (Sweden)

Full Text Available The purpose of this study is to investigate the effects of aiming time and heart rate on the performance. Three elite female national subject was used in this study. The shooting performance was observed only in 70 m. To evaluate heart rate, Delta Plus CP/I portable, interpreting model ECG, to determine the releasing time double channel ME 3000 micro-processor, Muscle Tester were used. The results of the study; the shooting heart rate is116,2±7,16 bpm., aiming time is 3,56±0,59 s. And the heart rate of the time between two shooting is 113,13±9,54 bpm. According to statistical analysis, a significant difference between shooting HR and aiming time of arrows which hit the different point on the target has been observed (p<0,05.The relationships between shooting HR-performance and shooting HR-Aiming time have been observed.While shootings come close to the center of the target (through the 10 point the shooting heart rate and aiming time has decreased and there is no change in the value of the heart rate of the time between two shooting.

?pek Ero?lu Kolayi?

2008-05-01

372

Changes in the Heart Rate Variability in Patients with Obstructive Sleep Apnea and Its Response to Acute CPAP Treatment  

Science.gov (United States)

Introduction Obstructive Sleep Apnea (OSA) is a major risk factor for cardiovascular disease. The goal of this study was to demonstrate whether the use of CPAP produces significant changes in the heart rate or in the heart rate variability of patients with OSA in the first night of treatment and whether gender and obesity play a role in these differences. Methods Single-center transversal study including patients with severe OSA corrected with CPAP. Only patients with total correction after CPAP were included. Patients underwent two sleep studies on consecutive nights: the first night a basal study, and the second with CPAP. We also analyzed the heart rate changes and their relationship with CPAP treatment, sleep stages, sex and body mass index. Twenty-minute segments of the ECG were selected from the sleep periods of REM, no-REM and awake. Heart rate (HR) and heart rate variability (HRV) were studied by comparing the R-R interval in the different conditions. We also compared samples from the basal study and CPAP nights. Results 39 patients (15 females, 24 males) were studied. The mean age was 50.67 years old, the mean AHI was 48.54, and mean body mass index was 33.41 kg/m2 (31.83 males, 35.95 females). Our results showed that HRV (SDNN) decreased after the use of CPAP during the first night of treatment, especially in non-REM sleep. Gender and obesity did not have any influence on our results. Conclusions These findings support that cardiac variability improves as an acute effect, independently of gender or weight, in the first night of CPAP use in severe OSA patients, supporting the idea of continuous use and emphasizing that noncompliance of CPAP treatment should be avoided even if it is just once.

Lopez, Jon; Alegre, Manuel; Urrestarazu, Elena; Artieda, Julio; Iriarte, Jorge

2012-01-01

373

Investigating the effects of cognitive interventions on reducing pain intensity and modifying heart rate and oxygen saturation level  

Directory of Open Access Journals (Sweden)

Full Text Available Introduction:In the present study, we investigated the efficacy of cognitive interventions in reducing reported pain intensity as well as modifying heart rate or oxygen saturation level in children with cancer during lumbar puncture or intrathecal injection. Moreover, we studied the relationship between the reported pain intensity and changes in heart rate and oxygen saturation level resulting from lumbar puncture or intrathecal injection.Material and Methods:This is a clinical trial using a pretest-posttest design with control group. 41 child-parent pairs were selected and randomly assigned to two groups. The children were visited twice; on first visit, both groups received routine care. On second visit, the experiment group received cognitive interventions and the second group received routine care. Data were collected using a demographic questionnaire, Oucher’s self-report pain intensity scale, and pulse oximeter. We used analysis of covariance and Pearson’s correlation to analyze the data.Results:Our findings indicate that the interventions efficiently reduce reported pain intensity, lower heart rate and increase blood oxygen saturation level during lumbar puncture or intrathecal injection. We also found a significant positive correlation between reported pain intensity and changes in heart rate, and a significant negative relationship between reported pain intensity and changes in oxygen saturation level. Conclusion:Cognitive interventions are efficient for reducing reported pain intensity, lowering heart rate and increasing oxygen saturation level during lumbar puncture or intrathecal injection. We recommend cognitive interventions to be used during this painful procedure to manage pain and minimize physiologic changes resulting from lumbar puncture.

Shahriar Shahidi

2011-10-01

374

Effect of Exercise Testing on Short-term Heart Rate Variability in Patients with Coronary Heart Disease  

DEFF Research Database (Denmark)

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 showed that (1) No significant difference was detected in 5-minute frequency domain (LFnorm, HFnorm and LF/HF) of stationary supine position before exercise (P0.05) between CHD and controls. In CHD, there was no significant difference in 5-minute frequency spectral components of supine position between pre-exercise and post-exercise results (P0.05); (2) All of LFnorm, HFnorm and LF/HF were found to decrease gradually during ET and to reach the lowest levels in maximal ET and to increase during the recovery period in both CHD and controls (P0.05).Between the two groups, significant difference was shown in the second 5-minute frequency domain analysis (LFnorm, HFnorm and LF/HF) after ET(P0.05); (3) In the whole course of ET,the frequency domain analysis showed that LF and LFnorm were higher and HF,HFnorm were lower in CHD than those in controls.Conclusion It is concluded that (1) Sympathovagal nervous system remains balanced in patients with CHD in stationary supine position without myocardiac ischemia; (2) Vagal tone withdraws during the exercise time and increases during the recovery period; (3) The changes of HRV in patients with CHD present ischemia-induced reflective sympathetic activity predominance during the recovery period; (4) The autonomic nervous system in CHD is disordered during ET. This results suggest that ET is helpful in detecting the disorder of sympathovagal nervous system in patients with CHD.

Niu, Hui-Yan; Zhang, Dai-Fu

2005-01-01

375

Prognostic Value of Ambulatory Heart Rate Revisited in 6928 Subjects From 6 Populations.  

DEFF Research Database (Denmark)

The evidence relating mortality and morbidity to heart rate remains inconsistent. We performed 24-hour ambulatory blood pressure monitoring in 6928 subjects (not on β-blockers; mean age: 56.2 years; 46.5% women) enrolled in prospective population studies in Denmark, Belgium, Japan, Sweden, Uruguay, and China. We computed standardized hazard ratios for heart rate, while stratifying for cohort, and adjusting for blood pressure and other cardiovascular risk factors. Over 9.6 years (median), 850, 325, and 493 deaths accrued for total, cardiovascular, and noncardiovascular mortality, respectively. The incidence of fatal combined with nonfatal end points was 805, 363, 439, and 324 for cardiovascular, stroke, cardiac, and coronary events, respectively. Twenty-four-hour heart rate predicted total (hazard ratio: 1.15) and noncardiovascular (hazard ratio: 1.18) mortality but not cardiovascular mortality (hazard ratio: 1.11) or any of the fatal combined with nonfatal events (hazard ratio: 1.02). Daytime heart rate did not predict mortality (hazard ratio: 1.11) or any fatal combined with nonfatal event (hazard ratio: 0.96). Nighttime heart rate predicted all of the mortality outcomes (hazard ratio: 1.15) but none of the fatal combined with nonfatal events (hazard ratio: 1.11). The night:day heart rate ratio predicted total (hazard ratio: 1.14) and noncardiovascular mortality (hazard ratio: 1.12) and all of the fatal combined with nonfatal events (hazard ratio: 1.15) with the exception of stroke (hazard ratio: 1.06). Sensitivity analyses, in which we stratified by risk factors or from which we excluded 1 cohort at a time or the events occurring within 2 years of enrollment, showed consistent results. In the general population, heart rate predicts total and noncardiovascular mortality. With the exception of the night:day heart rate ratio, heart rate did not add to the risk stratification for fatal combined with nonfatal cardiovascular events. Thus, heart rate adds little to the prediction of cardiovascular risk.

Hansen, Tine Willum; Thijs, Lutgarde

2008-01-01

376

Heart rate variability in conscious neonatal swine: spectral features and responses to short-term intermittent hypoxia  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Spectral analysis of the cardiac time series has been used as a tool for assessing levels of parasympathetic and sympathetic modulation of the sinoatrial node. In the present investigation we evaluated daily changes in heart rate variability spectra in conscious neonatal piglets that were either neurally intact (n = 5 or had undergone right stellate ganglionectomy (n = 5. The partial stellectomized animals and their intact litter mates were exposed to four days of intermittent hypoxia, each day comprising nine episodes of hypoxia alternating with nine episodes of normoxia. A time control group (n = 7 comprised animals from different litters that were not exposed to intermittent hypoxia. We hypothesized that exposure to intermittent hypoxia would increase sympathetic efferent neuronal modulation of heart rate variability spectra in neurally intact animals and in those with right stellate ganglionectomy, and that his effect would be observed in heart rate variability spectra computed from baseline recordings. Results Overall, heart rate variability spectra during baseline conditions were dominated by high frequency activity, a reflection of parasympathetic efferent neuronal innervation and linkage to the ventilatory cycle manifested as respiratory sinus arrhythmia. Exposure to intermittent hypoxia did not alter daily baseline spectral features that would indicate an increase of sympathetic cardiac activity: low frequency (0.05 – 0.15 Hz activity was unaffected and the ratio of low- to -high frequency activity remained less than unity indicating a predominance of high frequency activity. The resultant spectra were remarkably similar despite differences in cardiac sympathetic efferent neuronal innervation and experimental treatment. When spectra were computed from cardiac time series during representative hypoxic episodes, significant increases in activity across the low frequency region (0.05 – 0.15 Hz of heart rate variability spectra were noted and were comparable in neurally intact animals and in those with right stellate ganglionectomy. Conclusion The findings of this investigation provided important information regarding sympathetic efferent neuronal innervation of the heart during the neonatal period. Both neurally intact animals and those with right stellate ganglionectomy had equivalent increases of activity in the low frequency region of heart rate variability spectra during hypoxic stimulation. Such a finding demonstrated the capability of residual cardiac sympathetic neuronal innervation to affect functionally appropriate changes in cardiac chronotropy.

Zhao Ning

2006-06-01

377

AMBIENT POLLUTION AND HEART RATE VARIABILITY. (R826780)  

Science.gov (United States)

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

378

Assessment of skeletal muscle fatigue of road maintenance workers based on heart rate monitoring and myotonometry  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Objective This research work is dedicated to occupational health problems caused by ergonomic risks. The research object was road building industry, where workers have to work very intensively, have long work hours, are working in forced/constrained work postures and overstrain during the work specific parts of their bodies. The aim of this study was to evaluate the work heaviness degree and to estimate the muscle fatigue of workers after one week work cycle. The study group consisted of 10 road construction and maintenance workers and 10 pavers aged between 20 and 60 years. Methods Physical load were analyzed by measuring heart rate (HR, work postures (OWAS and perceived exertion (RPE. Assessments of the muscles strain and functional state (tone were carried out using myotonometric (MYO measurements. The reliability of the statistical processing of heart rate monitoring and myotonometry data was determined using correlating analysis. Results This study showed that that road construction and repairing works should be considered as a hard work according to average metabolic energy consumption 8.1 ± 1.5 kcal/min; paving, in its turn, was a moderately hard work according to 7.2 ± 1.1 kcal/min. Several muscle tone levels were identified allowing subdivision of workers into three conditional categories basing on muscle tone and fatigue: I – absolute muscle relaxation and ability to relax; II – a state of equilibrium, when muscles are able to adapt to the work load and are partly able to relax; and III – muscle fatigue and increased tone. It was also found out that the increase of muscle tone and fatigue mainly depend on workers physical preparedness and length of service, and less – on their age. Conclusion We have concluded that a complex ergonomic analysis consisting of heart rate monitoring, assessment of compulsive working postures and myotonometry is appropriate to assess the work heaviness degree and can provide prognosis of occupational pathology or work-related musculoskeletal disorders for the workers under different workload conditions. These results can also be used when deciding on necessary rest time and its periodicity.

Kalkis Henrijs

2006-07-01

379

Modest weight loss in moderately overweight postmenopausal women improves heart rate variability  

DEFF Research Database (Denmark)

Purpose: To evaluate the effects of weight loss on heart rate (HR) and heart rate variability (HRV) parameters in overweight postmenopausal women. Design and Methods: Forty-nine overweight postmenopausal women with an average body mass index of 28.8 1.9 kg/m2 underwent a 12-week dietary weight-loss programme. Accepted variables for characterization of HRV were analysed before and after the weight loss by 24-h ambulatory ECG monitoring; mean and standard deviation for the time between normal-to-normal complexes (MeanNN and SDNN, respectively), and the mean of standard deviations of normal-to-normal intervals for each 5-min period (SDNNindex). Baseline body fat mass (FM%) and changes in body composition was determined by dual X-ray absorptiometry. Before and after the weight-loss period, total abdominal fat, intra-abdominal fat (IAAT), and subcutaneous abdominal fat (SCAT) were measured by single-slice MRI at L3. Results: The weight loss of 3.9 2.0 kg was accompanied by an improvement of HRV. SDNN increasedby 9.2% (p ¼ 0.003) and SDNNindex increased by 11.4% (p ¼ 0.0003). MeanNN increased by 2.4%, reflecting a decrease in mean heart rate from 74.1 to 72.3 beats/min (p ¼ 0.033). Systolic blood pressure (SBP) decreased by 2.7%, total cholesterol by 5.1% and high-sensitivity C-reactive protein (hsCRP) by 15.8% (p ¼ 0.002). Improvements in SDNN and cholesterol were correlated with weight loss (r ¼ 0.329, p ¼ 0.024 and r ¼ 0.327, p ¼ 0.020, respectively) but changes in HR, SBP, and hsCRP were not. IAAT and the IAAT/SCAT-ratio were found to be negatively associated with HRV parameters but changes in body composition were not associated with changes in HRV. Conclusions: The observed improvement of HRV seems to be facilitated by weight loss. IAAT and the IAAT/SCAT ratio were found to be associated with low HRV.

Mouridsen, Mette Rauhe; Bendsen, Nathalie Tommerup

2013-01-01

380

Analysis of Heart Rate and Self-Injury with and without Restraint in an Individual with Autism  

Science.gov (United States)

The relation between self-injury and heart rate was analyzed for an individual who appeared anxious while engaging in self-injury. The analysis involved manipulating the presence or absence of restraint while simultaneously measuring heart rate. The following findings were obtained and replicated: (a) when some form of restraint was applied, heart…

Jennett, Heather; Hagopian, Louis P.; Beaulieu, Lauren

2011-01-01