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1

[The resting heart rate].  

Science.gov (United States)

Assessment of resting heart rate is frequently performed and is easy, reliable and inexpensive. Heart rate is used in many algorithms to assess the prognosis of acutely ill patients. Elevated resting heart rate is independently related to the development of type 2 diabetes, cardiovascular disease and premature all-cause mortality. Adding heart rate to cardiovascular prediction models does not lead to improved prediction of vascular events or mortality. Beta blockers and non-dihydropyridine calcium channel blockers decrease heart rate (and blood pressure) and lower the risk of premature mortality in patients with heart failure or recent myocardial infarction. In two recent randomised trials, ivabradine specifically decreased heart rate (but not blood pressure) and the risk of cardiovascular events in patients with heart failure or coronary artery disease, decreased left ventricular function and resting heart rate of ? 70 beats/minute. Selective heart rate reduction is a potential treatment option to decrease cardiovascular risk. PMID:24666528

Bemelmans, Remy H H; Visseren, Frank L J

2014-01-01

2

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

3

Target Heart Rate Calculator  

Science.gov (United States)

... Saved Articles » My ACS » + - Text Size Target Heart Rate Calculator Compute your best workout Enter your age ... your age? years. How to Check Your Heart Rate Right after you stop exercising, take your pulse: ...

4

Tachycardia | Fast Heart Rate  

Science.gov (United States)

Tachycardia | Fast Heart Rate Updated:Sep 3,2014 Tachycardia = Too fast A heart rate of more than 100 beats per minute (BPM) in ... or Supraventricular tachycardia (SVT) is a fast heart rate that starts in the upper chambers of the ...

5

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

6

Heart Rate Monitors  

Science.gov (United States)

Under a NASA grant, Dr. Robert M. Davis and Dr. William M. Portnoy came up with a new type of electrocardiographic electrode that would enable long term use on astronauts. Their invention was an insulated capacitive electrode constructed of a thin dielectric film. NASA subsequently licensed the electrode technology to Richard Charnitski, inventor of the VersaClimber, who founded Heart Rate, Inc., to further develop and manufacture personal heart monitors and to produce exercise machines using the technology for the physical fitness, medical and home markets. Same technology is on both the Home and Institutional Model VersaClimbers. On the Home Model an infrared heart beat transmitter is worn under exercise clothing. Transmitted heart rate is used to control the work intensity on the VersaClimber using the heart rate as the speedometer of the exercise. This offers advantages to a full range of users from the cardiac rehab patient to the high level physical conditioning of elite athletes. The company manufactures and markets five models of the 1*2*3 HEART RATE monitors that are used wherever people exercise to accurately monitor their heart rate. Company is developing a talking heart rate monitor that works with portable headset radios. A version of the heart beat transmitter will be available to the manufacturers of other aerobic exercise machines.

1990-01-01

7

Target Heart Rates  

Science.gov (United States)

... Fit-Friendly Worksites Program Requirements Fit-Friendly Resources Target Heart Rates Updated:Sep 23,2014 How do ... people. It also rises with age. Hittin’ the Target Now you’re ready to determine your target ...

8

Heart Rate Monitor  

Science.gov (United States)

In the mid 70's, NASA saw a need for a long term electrocardiographic electrode suitable for use on astronauts. Heart Rate Inc.'s insulated capacitive electrode is constructed of thin dielectric film applied to stainless steel surface, originally developed under a grant by Texas Technical University. HRI, Inc. was awarded NASA license and continued development of heart rate monitor for use on exercise machines for physical fitness and medical markets.

1984-01-01

9

Conclusion  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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; Virginie Amilien

2007-01-01

10

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

11

Blood Pressure vs. Heart Rate  

Science.gov (United States)

Blood Pressure vs. Heart Rate Updated:Sep 4,2014 Blood pressure and heart rate are not the same. Learn ... last reviewed on 08/04/2014. High Blood Pressure • Home • About High Blood Pressure (HBP) Introduction What ...

12

All about Heart Rate (Pulse)  

Science.gov (United States)

All About Heart Rate (Pulse) Updated:Sep 30,2014 What should you know about your heart rate? Even if you’re not an athlete, knowledge ... is it and what is a normal heart rate? The best places to find your pulse are ...

13

Regulation of Human Heart Rate  

Science.gov (United States)

Students learn how to measure heart rate accurately. Then students design and carry out an experiment to test the effects of an activity or stimulus on heart rate, analyze and interpret the data, and present their experiments in a poster session. In this activity students learn about both cardiac physiology and experimental method.

Waldron, Ingrid

14

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

15

Dimensional analysis of heart rate variability in heart transplant recipients  

Energy Technology Data Exchange (ETDEWEB)

We discuss periodicities in the heart rate in normal and transplanted hearts. We then consider the possibility of dimensional analysis of these periodicities in transplanted hearts and problems associated with the record.

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

1987-01-01

16

Interaction between heart rate and heart rate variability.  

Science.gov (United States)

Heart rate variability (HRV) is significantly associated with average heart rate (HR), therefore, HRV actually provides information on two quantities, that is, on HR and its variability. It is difficult to conclude which of these two plays a principal role in the HRV clinical value, or in other words, what is the HR contribution to the clinical significance of HRV. Moreover, the association between HRV and HR is both a physiological phenomenon and a mathematical one. The physiological HRV dependence on HR is determined by the autonomic nervous system activity, but the mathematical one is caused by the nonlinear relationship between RR interval and HR. By employing modification methods of the HRV and HR relationship, it is possible to investigate the HR contribution to the HRV clinical value. Recent studies have shown that the removal of the HR impact on HRV makes HRV more predictive for noncardiac death, however, the enhancement of this impact causes HRV to be a better predictor of cardiovascular mortality. Thus, HR seems to constitute a cardiovascular factor of the HRV predictive ability. HR also influences the reproducibility of HRV, therefore, HR changes should be considered when one compares HRV measurements in a given patient. This review summarizes methodological aspects of investigations of the HRV and HR interaction as well as latest observations concerning its clinical utility. The issues discussed in this article should also refer to any other heart rate dynamics analysis which indices are significantly associated with HR. PMID:24602150

Sacha, Jerzy

2014-05-01

17

Conclusion; Conclusion  

Energy Technology Data Exchange (ETDEWEB)

The carcinogenic effect of ionizing radiation has become the main issue in radioprotection since the data seem to show that the genetic effect is less important than was formerly thought. The hypothesis of a linear no threshold (LNT) relationship, which means that the hazard of carcinogenesis is proportional to dose, was introduced in 1965 (ICRP report no.9) in order to simplify the administrative assessment of cancer risk. The validity of the LNT relationship has been challenged by several senior radiation biologists. Hence, The Academie des Sciences felt that it was timely to organize a symposium during which proponents and opponents of LNT could calmly discuss the various facets of this problem. The first sessions were devoted to microdosimetry and DNA repair. The third part of the meeting was devoted to the mechanisms of carcinogenesis in humans. The discussion throughout the meeting emphasized the avenues which should be explored for a better understanding of human radioinduced carcinogenesis, in particular the dose effect relationship for ds DNA breaks and the impact of dose rate, apoptosis, radioinduced genetic instability, epigenetic effect, as well as epidemiological studies focused on the effect of low doses in patients and on individuals from the regions of the world where background natural irradiation is high. (N.C.)

Sarasin, A.; Tubiana, M

1999-03-01

18

How to Take Your Heart Rate  

Science.gov (United States)

... effective for your body. How to Take Your Heart Rate Taking your pulse during physical activity allows you ... years) 50% (BPM) 70% (BPM) 85% (BPM) Maximum Heart Rate (BPM) 20 100 140 170 200 25 98 ...

19

Influence of heart failure severity on heart rate variability  

Directory of Open Access Journals (Sweden)

Full Text Available 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 heart failure severity on HRV. Method. HRV was estimated through the spectral analysis of short term ECG (Cardiovit AT 60, Schiller, CH in 63 patients (78% male, mean age 56.9±10.9 years and 14 healthy volunteers (57.1% male, mean age 53.1±8.2 years. The following spectral components were measured: VLF (very low frequency, LF (low frequency, HF (high frequency, and total power (Tot Power. Results. All spectral components were statistically, significantly lower in patients with heart failure in comparison to healthy controls (VLF: 159.89±147.02 vs. 285.50±202.77 ms2; p=0.023, LF: 161.48±204.01 vs. 474.57±362.93 ms2; p<0.001, HF: 88.58±102.47 vs. 362.71±318.28 ms2; p<0.001, as well as total power (Tot Power: 723.39±644.52 vs. 1807.29±1204.74 ms2; p<0.001. A significant, negative correlation between HRV parameters and NYHA class was detected in heart failure patients (VLF: r=-0.391; p=0.002, LF: r=-0.401; p=0.001, and Tot Power r=-0.372; p=0.003. Ejection fraction proved to be in significant, positive correlation to VLF (r=0.541; p=0.002, LF (r=0.531; p=0.003, HF (r=0.418; p=0.020, and Tot Power (r=0.457; p=0.013. Conclusion. Significant HRV reduction is a precursor to incipient heart failure (NYHA I. In heart failure progression, total power as well as the power of all spectral components is progressively reduced. LF and Tot Power are the most prominent parameters for discriminating between the different stages of heart failure. These results could promote HRV as an important decision-making tool in heart failure treatment as well as in monitoring the results of that treatment.

Zamaklar-Trifunovi? Danijela

2005-01-01

20

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

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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

 
 
 
 
21

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

22

8.F Heart Rate Monitoring  

Science.gov (United States)

This is a task from the Illustrative Mathematics website that is one part of a complete illustration of the standard to which it is aligned. Each task has at least one solution and some commentary that addresses important asects of the task and its potential use. Here are the first few lines of the commentary for this task: Serena is starting a new workout routine and wants to keep track of her heart rate to make sure that she is exercising at the optimum level. First she ...

23

Assessing resting heart rate in adolescents: determinants and correlates.  

Science.gov (United States)

The aim of this study was to evaluate the distribution of resting heart rate and its biological and environmental determinants in adolescents. The study was cross- sectional and the population consisted of 2230 children and adolescents, age range 12-18 years, enrolled randomly from state schools in Turin, Italy. In all participants the following parameters were evaluated: heart rate, blood pressure (BP), weight, height, degree of sexual development, physical activity, parental socio-cultural level. Heart rate and BP were measured after 5, 10 and 15 min in a sitting position. Furthermore, to obtain regression equations to define heart rate as a function of the other variables available, a multiple regression analysis was performed. In both sexes BP, but not heart rate, declined significantly from the first to the last determination. Heart rate was positively and significantly correlated to BP level in both sexes; heart rate was higher in girls (3 bpm) and followed a progressive decreasing trend with age in both sexes, that was opposite to BP values. Age, sexual maturation, height, physical activity and parental socio-cultural level were independent determinants of resting heart rate. In conclusion, resting heart rate in adolescents is related to several methodological, constitutional and environmental factors that have to be taken into account when assessing heart rate values and constructing tables of normal values. PMID:12082493

Rabbia, F; Grosso, T; Cat Genova, G; Conterno, A; De Vito, B; Mulatero, P; Chiandussi, L; Veglio, F

2002-05-01

24

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...

Billman, George E.

2011-01-01

25

Stereotypic behavior and heart rate in pigs.  

Science.gov (United States)

Heart rate responses to feeding of both loose-housed and tethered sows, some of which engaged in persistent behavioral stereotypies, were recorded telemetrically in order to determine if stereotypic behavior occurs in response to, and serves to reduce increased sympathetic nervous activity. Heart rates rose in response to feeding (after which stereotypic behavior is most common) and this was greater for tethered sows. This response was partly blocked by a beta-adrenoreceptor antagonist (carazolol), but not by naloxone, although the latter tended to lead to overall increases in heart rate. Thus long-term tethering of sows leads to greater sympathetic nervous responses to feeding. No consistent relationships were found between heart rate and the performance of stereotypic behavior. In Experiment 1, using sows tethered for 6-8 months, neither basal heart rates nor heart rates following naloxone or carazolol differed between high- and low-stereotyping sows. In Experiment 2, using sows tethered for 1-2 months, high-stereotyping sows had lower basal heart rates than low-stereotyping sows. Marked reductions in heart rate caused by a beta-adrenoreceptor blocker did not lead to any change in stereotypic behavior, and preventing stereotypic behavior led to a reduction not an increase in heart rates. The results suggest that stereotypies are performed in situations where heart rate is high, but they provide no evidence that stereotypies reduce this heart rate. PMID:1686938

Schouten, W; Rushen, J; De Passillé, A M

1991-09-01

26

Scale Invariant Properties in Heart Rate Signals  

International Nuclear Information System (INIS)

The rate of heart beat is controlled by autonomic nervous system: accelerated by the sympathetic system and slowed by the parasympathetic system. Scaling properties in heart rate are usually related to the intrinsic dynamics of this physiological regulatory system. The two packages calculating local exponent spectra: Wavelet Transform Modulus Maxima and Multifractal Detrended Fluctuation Analysis (accessible from Physionet home page http://circ.ahajournals.org/cgi/content/full/101/23/e215) are tested, and then used to investigate the spectrum of singularity exponents in series of heart rates obtained from patients suffering from reduced left ventricle systolic function. It occurs that this state of a heart could be connected to some perturbation in the regulatory system, because the heart rate appears to be less controlled than in a healthy human heart. The multifractality in the heart rate signal is weakened: the spectrum is narrower and moved to higher values what indicate the higher activity of the sympatethic nervous system. (author)

27

Scale Invariant Properties in Heart Rate Signals  

Science.gov (United States)

The rate of heart beat is controlled by autonomic nervous system: accelerated by the sympathetic system and slowed by the parasympathetic system. Scaling properties in heart rate are usually related to the intrinsic dynamics of this physiological regulatory system. The two packages calculating local exponent spectra: Wavelet Transform Modulus Maxima and Multifractal Detrended Fluctuation Analysis (accessible from Physionet home page http://circ.ahajournals.org/cgi/content/full/101/23/e215) are tested, and then used to investigate the spectrum of singularity exponents in series of heart rates obtained from patients suffering from reduced left ventricle systolic function. It occurs that this state of a heart could be connected to some perturbation in the regulatory system, because the heart rate appears to be less controlled than in a healthy human heart. The multifractality in the heart rate signal is weakened: the spectrum is narrower and moved to higher values what indicate the higher activity of the sympatethic nervous system.

Makowiec, D.; Dudkowska, A.; Zwierz, M.; Galaska, R.; Rynkiewicz, A.

2006-05-01

28

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

Science.gov (United States)

Abstract Objectives. In the clinical setting, patients with slower resting heart rate are less prone to cardiovascular death compared with those with elevated heart rate. However, electrophysiological adaptations associated with reduced cardiac rhythm have not been thoroughly explored. In this study, relationships between intrinsic heart rate and arrhythmic susceptibility were examined by assessments of action potential duration (APD) rate adaptation and inducibility of repolarization alternans in sinoatrial node (SAN)-driven and atrioventricular (AV)-blocked guinea-pig hearts perfused with Langendorff apparatus. Design. Electrocardiograms, epicardial monophasic action potentials, and effective refractory periods (ERP) were assessed in normokalemic and hypokalemic conditions. Results. Slower basal heart rate in AV-blocked hearts was associated with prolonged ventricular repolarization during spontaneous beating, and with attenuated APD shortening at increased cardiac activation rates during dynamic pacing, when compared with SAN-driven hearts. During hypokalemic perfusion, the inducibility of repolarization alternans and tachyarrhythmia by rapid pacing was found to be lower in AV-blocked hearts. This difference was ascribed to prolonged ERP in the setting of reduced basal heart rate, which prevented ventricular capture at critically short pacing intervals required to induce arrhythmia. Conclusions. Reduced basal heart rate is associated with electrophysiological changes that prevent electrical instability upon an abrupt cardiac acceleration. PMID:25334079

Osadchii, Oleg E

2014-12-01

29

Heart Rate Turbulence: a Review  

Directory of Open Access Journals (Sweden)

Full Text Available Heart rate turbulence (HRT is a recently coined phrase that describes the short term fluctuation in sinus cycle length that follows a ventricular premature complex (VPC. Its proven clinical significance lies in its ability to predict mortality and sudden cardiac death following myocardial infarction, although small studies suggest that it is also applicable to many other cardiac diseases. This review will attempt to summarize the literature to date, and to speculate on possible mechanisms. Because HRT is a new field, there are only a handful of full length papers on it. In order to present the full breadth of the research being carried out, the information provided here is based on conference abstracts as well as peer reviewed articles, and readers should keep this in mind. Most of the literature cited here, and downloadable HRT calculation programs (in C++ are available on the website www.h-r-t.org.

Mari A. Watanabe

2003-01-01

30

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...

Schimpf, Klaus

2013-01-01

31

A stochastic model for heart rate fluctuations  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Normal human heart rate shows complex fluctuations in time, which is natural, since heart rate is controlled by a large number of different feedback control loops. These unpredictable fluctuations have been shown to display fractal dynamics, long-term correlations, and 1/f noise. These characterizations are statistical and they have been widely studied and used, but much less is known about the detailed time evolution (dynamics) of the heart rate control mechanism. Here we s...

Kuusela, Tom A.; Shepherd, Tony; Hietarinta, Jarmo

2002-01-01

32

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

33

Heart Rates of Elite Synchronized Swimmers.  

Science.gov (United States)

Heart rates were recorded by radiotelemetry in ten elite and national-class synchronized swimmers as they performed competitive figures of high degrees of difficulty. The focus was on changes in heart rates and electrocardiogram patterns for each body position, especially those requiring facial immersion and breath-holding. (Author/MT)

Gemma, Karen Erickson; Wells, Christine L.

1987-01-01

34

Heart Rate and Reinforcement Sensitivity in ADHD  

Science.gov (United States)

Background: Both theoretical and clinical accounts of attention-deficit/hyperactivity disorder (ADHD) implicate a dysfunctional reinforcement system. This study investigated heart rate parameters in response to feedback associated with reward and response cost in ADHD children and controls aged 8 to 12. Methods: Heart rate responses (HRRs)…

Luman, Marjolein; Oosterlaan, Jaap; Hyde, Christopher; van Meel, Catharina S.; Sergeant, Joseph A.

2007-01-01

35

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

36

Heart Rate Variability in Obstructive Sleep Apnea.  

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Full Text Available 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 time-domain and frequency-domain methods. This study was undertaken to compare the HRV in patients with Obstructed Sleep Apnoea Syndrome (OSAS and normal subjects. Methods: Heart rate variability in 30 controls (Group I and 30 patients with Obstructive Sleep Apnea Syndrome (Group II aged 35-45 yrs was studied by using electrocardiographic data obtained during Polysomnography. Low frequency (LF power, High frequency (HF power and Low frequency/ High frequency ratio (LF/HF were analyzed using frequency-domain analysis. Results: There was a significant difference (p Conclusion: In our study, there was evidence of increased Sympathetic activity and a Parasympathetic attenuation in patients with Obstructive Sleep Apnea. Further studies can evaluate the usefulness of HRV indices for the non-invasive screening of asymptomatic patients suspected to have OSAS.

Selvakumar Jagannathan

2013-07-01

37

Spatiotemporal control of heart rate in a rabbit heart.  

Science.gov (United States)

Sinoatrial node is responsible for the origin of the wave of excitation, which spreads throughout the heart and orchestrates cardiac contraction via calcium-mediated excitation-contraction coupling. P wave represents the spread of excitation in the atria. It is well known that the autonomic nervous system controls the heart rate by dynamically altering both cellular ionic fluxes and the anatomical location of the leading pacemaker. In this study, we used isolated rabbit right atria and mathematical model of the pacemaker region of the rabbit heart. Application of isoproterenol resulted in dose-dependent acceleration of the heart rate and superior shift of the leading pacemaker. In the mathematical model, such behavior could be reproduced by a gradient of expression in ?1-adrenergic receptors along the superior-inferior axis. Application of acetylcholine resulted in preferentially inferior shift of pacemaker and slowing of the heart rate. The mathematical model reproduced this behavior with imposing a gradient of expression of acetylcholine-sensitive potassium channel. We conclude that anatomical shift of the leading pacemaker in the rabbit heart could be achieved through gradient of expression of ?1-adrenergic receptors and I(K,ACh). PMID:21937057

Lang, Di; Petrov, Valentin; Lou, Qing; Osipov, Grigory; Efimov, Igor R

2011-01-01

38

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

39

The relationship between phase and heart rate  

International Nuclear Information System (INIS)

n from 18 degree to 12 degree. It is concluded that correcting phase for heart rate below 90 beats per minute will increase the sensitivity of the phase image to abnormalities of the timing of ventricular contraction. This correction should be appropriate in resting, isometric exercise, and cold pressor studies but because of the higher heart rates involved will not be appropriate for bicycle exercise. (Author)

40

What is the “normal” fetal heart rate?  

Directory of Open Access Journals (Sweden)

Full Text Available Aim. There is no consensus about the normal fetal heart rate. Current international guidelines recommend for the normal fetal heart rate (FHR baseline different ranges of 110 to 150 beats per minute (bpm or 110 to 160 bpm. We started with a precise definition of “normality” and performed a retrospective computerized analysis of electronically recorded FHR tracings. Methods. We analyzed all recorded cardiotocography tracings of singleton pregnancies in three German medical centers from 2000 to 2007 and identified 78,852 tracings of sufficient quality. For each tracing, the baseline FHR was extracted by eliminating accelerations/decelerations and averaging based on the “delayed moving windows” algorithm. After analyzing 40% of the dataset as “training set” from one hospital generating a hypothetical normal baseline range, evaluation of external validity on the other 60% of the data was performed using data from later years in the same hospital and externally using data from the two other hospitals. Results. Based on the training data set, the “best” FHR range was 115 or 120 to 160 bpm. Validation in all three data sets identified 120 to 160 bpm as the correct symmetric “normal range”. FHR decreases slightly during gestation. Conclusions. Normal ranges for FHR are 120 to 160 bpm. Many international guidelines define ranges of 110 to 160 bpm which seem to be safe in daily practice. However, further studies should confirm that such asymmetric alarm limits are safe, with a particular focus on the lower bound, and should give insights about how to show and further improve the usefulness of the widely used practice of CTG monitoring.

Stephanie Pildner von Steinburg

2013-06-01

 
 
 
 
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Interdependence of parameters of varia-tional pulsometry, entropy of heart rate, temporal and spectral analyses of heart rate variability in normal state and in ischemic heart disease  

Directory of Open Access Journals (Sweden)

Full Text Available The research goal is to study the correlation between indices of variational pulsometry, entropy of heart rate, temporal and spectral analyses and heart rate variability in healthy patients and patients with coronary heart disease. Materials. Of the study are indicators of variational pulsometry and temporal and spectral analyses from 111 patients with coronary heart disease and in 61 healthy individuals. Results. Most parameters of HRV correlated with each other. In healthy patients the greatest independence was characterized by Mo and LF/HF, in patients with coronary artery disease — only by LF/HF Significant correlation with SDNN RMSSD, TP, LF, HF was determined. Conclusion. The variational pulsometry, temporal and spectral analyses of HRV and entropy of heart rate provide HRV assessment. The indices are interdependent and indicate interchangeability of methods

Durnova N.Yu.

2011-09-01

42

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

43

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

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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.

Vasyuk, Y. A.; Shupenina, E. Y.; Yuschuk, ?. N.; Serova, ?. ?.

2006-01-01

44

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...

Fei, L.; Keeling, P. J.; Gill, J. S.; Bashir, Y.; Statters, D. J.; Poloniecki, J.; Mckenna, W. J.; Camm, A. J.

1994-01-01

45

A Novel Thermal Measurement for Heart Rate  

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Full Text Available Heart rate is an important indicator for the mental and physical state, but it is usually measured through physical contact. In this paper, a novel non-contact method of heart rate measurement has been proposed from the infrared sequence images. First, a square region of interest (ROI was manually selected to cover the temple on the first frame. Then a head movement detection algorithm based on the centroid coordinate change of the extracted skin area was applied to the infrared sequence images, and according to the movement result, the ROI location in subsequent frames could be identified. After that, the distance between the gravity center and the top-left corner in every ROI is computed to get a time-lapse signal. Finally, the discrete wavelet transform and an autoregressive model were used respectively to recognize the heart rate. Fourteen healthy subjects (24-29 years of age, 4 females and 10 males participated in the experiment. Compared with the concomitant ECG, mean accuracy rate of 94.5% was acquired. The results show the potential of our method for non-contact heart rate measurement.

Bin Jing

2013-09-01

46

Wireless monitoring of Heart Rate using Microcontroller  

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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

47

Heart rate dynamics during a treadmill cardiopulmonary exercise test in optimized beta-blocked heart failure patients  

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Full Text Available BACKGROUND: Calculating the maximum heart rate for age is one method to characterize the maximum effort of an individual. Although this method is commonly used, little is known about heart rate dynamics in optimized beta-blocked heart failure patients. AIM: The aim of this study was to evaluate heart rate dynamics (basal, peak and % heart rate increase in optimized beta-blocked heart failure patients compared to sedentary, normal individuals (controls during a treadmill cardiopulmonary exercise test. METHODS: Twenty-five heart failure patients (49±11 years, 76% male, with an average LVEF of 30±7%, and fourteen controls were included in the study. Patients with atrial fibrillation, a pacemaker or noncardiovascular functional limitations or whose drug therapy was not optimized were excluded. Optimization was considered to be 50 mg/day or more of carvedilol, with a basal heart rate between 50 to 60 bpm that was maintained for 3 months. RESULTS: Basal heart rate was lower in heart failure patients (57±3 bpm compared to controls (89±14 bpm; p<0.0001. Similarly, the peak heart rate (% maximum predicted for age was lower in HF patients (65.4±11.1% compared to controls (98.6±2.2; p<0.0001. Maximum respiratory exchange ratio did not differ between the groups (1.2±0.5 for controls and 1.15±1 for heart failure patients; p=0.42. All controls reached the maximum heart rate for their age, while no patients in the heart failure group reached the maximum. Moreover, the % increase of heart rate from rest to peak exercise between heart failure (48±9% and control (53±8% was not different (p=0.157. CONCLUSION: No patient in the heart failure group reached the maximum heart rate for their age during a treadmill cardiopulmonary exercise test, despite the fact that the percentage increase of heart rate was similar to sedentary normal subjects. A heart rate increase in optimized beta-blocked heart failure patients during cardiopulmonary exercise test over 65% of the maximum age-adjusted value should be considered an effort near the maximum. This information may be useful in rehabilitation programs and ischemic tests, although further studies are required.

Vitor Oliveira Carvalho

2008-01-01

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

Science.gov (United States)

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

Kirkpatrick, Beth; Birnbaum, Burton H.

49

Fetal heart rate variation with umbilical haematoma.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Umbilical cord haematoma is an infrequent condition associated with high perinatal and fetal mortality and morbidity. This report describes a rare case of umbilical cord haematoma associated with loss of fetal beat to beat variation during labour. The infant exhibited mild asphyxia only. Previous publications are reviewed and fetal heart rate changes associated with umbilical cord haematoma are discussed.

Ballas, S.; Gitstein, S.; Kharasch, J.

1985-01-01

50

Music determines heart rate variability of singers  

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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

51

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

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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

52

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

Science.gov (United States)

The effect of trophotropic (relaxing) music on heart rate and heart rate variability has been investigated in 23 healthy young individuals by means of 24-hour Holter-ECG. Relaxing music (Bach, Vivaldi, Mozart) resulted in significant reduction of heart rate and also significant reduction of heart rate variability. The significance of these results for the use of music in coronary heart disease is discussed. PMID:10412282

Escher, J; Evéquoz, D

1999-05-20

53

Effect of endotoxemia on heart rate dynamics in rat isolated perfused hearts  

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Full Text Available Introduction: Beat-to-beat variation in heart rate shows a complex dynamics, and this complexity is changed during systemic inflammatory response syndrome (e.g. sepsis. It is not known whether or not cardiac pacemaker dynamical rhythm is affected by sepsis. The aim of this study was to investigate heart rate dynamics of isolated heart as well as expression of pacemaker channels (HCN in a rat model of sepsis (endotoxemia compared with normal rats. Methods: Male rats weighing 250-300 g were used in this study. Bacterial lipopolysaccharide was injected intraperitoneally (1mg/kg in the endotoxemia group, and sterile saline in the control group. Three hours after injection, cardiac tissues were isolated and studied using Langendorff apparatus. Heart rate dynamics was assessed by calculating the standard deviation of inter-beat intervals as well as detrended fluctuation analysis (DFA. Quantitative RT-PCR was used to assess HCN expression in atria. Results: Hypoxia had a significantly different effect on heart rate variability in endotoxemic rats compared with controls (P<0.05. DFA analysis showed a linear relationship between logarithm of variance and the logarithm of scale in both endotoxemic and control rats. Atrial expression of HCN1 and HCN2 at mRNA level were significantly higher in endotoxemic rats in comparison with controls (P<0.05. Conclusion: Spontaneous beatings of isolated hearts exhibit a fractal-like dynamics which did not change after global hypoxia and/or endotoxemia. Endotoxemia was associated with altered heart rate variability and increased expression of pacemaker channels that might play a role in pathophysiology of cardiac complications of sepsis.

Mohammad Karim Azadbakht

2013-03-01

54

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.

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

55

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.

Almeida Marcos B.

2003-01-01

56

Fetal heart rate classification using generative models.  

Science.gov (United States)

This paper presents novel methods for classification of fetal heart rate (FHR) signals into categories that are meaningful for clinical implementation. They are based on generative models (GMs) and Bayesian theory. Instead of using scalar features that summarize information obtained from long-duration data, the models allow for explicit use of feature sequences derived from local patterns of FHR evolution. We compare our methods with a deterministic expert system for classification and with a support vector machine approach that relies on system-identification and heart rate variability features. We tested the classifiers on 83 retrospectively collected FHR records, with the gold-standard true diagnosis defined using umbilical cord pH values. We found that our methods consistently performed as well as or better than these, suggesting that the use of GMs and the Bayesian paradigm can bring significant improvement to automatic FHR classification approaches. PMID:24951678

Dash, Shishir; Quirk, J Gerald; Djuric, Petar M

2014-11-01

57

Dynamic Metrics of Heart Rate Variability  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Numerous metrics of heart rate variability (HRV) have been described, analyzed, and compared in the literature. However, they rarely cover the actual metrics used in a class of HRV data acquisition devices - those designed primarily to produce real-time metrics. This paper characterizes a class of metrics that we term dynamic metrics. We also report the results of a pilot study which compares one such dynamic metric, based on photoplethysmographic data using a moving samplin...

Goss, Clinton F.; Miller, Eric B.

2013-01-01

58

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

59

Case Studies in Electronic Fetal Heart Rate Monitoring  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Yee, J.; Parboosingh, I. J.

1986-01-01

60

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

 
 
 
 
61

Heart Rate Responses During Singles and Doubles Tennis Competition.  

Science.gov (United States)

Monitoring of heart rates of 17 adult male tennis players during singles and doubles competition revealed that subjects playing singles games reached an average of 61 percent of their maximal heart rate, while, in doubles competition, they reached only 33 percent of maximal heart rate. (Author/CB)

Morgans, Leland F.; And Others

1987-01-01

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

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

Directory of Open Access Journals (Sweden)

Full Text Available 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 effects of this respiratory pattern on HRV were not evaluated. Objective. The aim of the study was to estimate effects of slow and deep breathing (SDB on HRV in heart failure patients. Method. In 55 patients with heart failure (78% male, mean age 57.18±10.8 yrs, mean EF=34.12±10.01% and 14 healthy controls (57.1% male, mean age 53.1±8.2 yrs, short term HRV spectral analysis was performed (Cardiovit AT 60, Schiller. VLF, LF, HF and LF/HF were determined during spontaneous and deep and slow breathing at 0.1 Hz (SDB. Results. LF, HF and LF/HF significantly increased during SDB compared with spontaneous breathing both in controls (LF 50.71±61.55 vs. 551.14±698.01 ms2, p<0.001; HF 31.42±29.98 vs.188.78±142.74 ms2, p<0.001 and LF/HF 1.46±0.61 vs. 4.21±3.23, p=0.025 and heart failure patients (LF 27.37±36.04 vs. 94.50±96.13 ms2, p<0.001; HF 12.13±19.75 vs. 41.58±64.02 ms2, p<0.001 and LF/HF 3.77±3.79 vs. 6.38±5.98, p=0.031. Increments of LF and HF induced by SDB were significantly lower in patients than healthy controls. Heart failure patients had lower HRV compared to healthy controls both during spontaneous breathing and SDB. During spontaneous breathing, only HF was significantly lower between healthy controls and patients (p=0.002. During SDB VLF (p=0.022, LF (p<0.001 and HF (p<0.001 were significantly lower in heart failure patients compared to controls. Conclusion. These data suggest that SDB increases HRV both in healthy and heart failure patients; the highest increment is in LF range. Differences in spectral profile of HRV between healthy controls and heart failure patients become more profound during SDB. Controlled respiration during HRV analysis might increase sensitivity and reliability in detection of autonomic dysfunction in heart failure patients. .

Zamaklar-Trifunovi? Danijela

2007-01-01

64

What's Normal? -- Temperature, Gender, and Heart Rate  

Science.gov (United States)

This article, created by Allen L. Shoemaker of Calvin College, describes a dataset on body temperature, gender, and heart rate. The data is taken from a paper in the "Journal of the American Medical Association" that examined whether humans' true body temperature was 98.6 degrees. It addresses concepts like true means, confidence intervals, t-statistics, t-tests, the normal distribution, and regression. The author states that "it helps students to grasp concepts about true means, confidence intervals and t-statistics." This is a nice introduction into how statistics can be used in the medical field.

Shoemaker, Allen L.

2009-06-19

65

Frequency Structure of Heart Rate Variability  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Factor structure of heart rate periodogram has been detected with factor analysis. The results showed that there are at least four periodical phenomena of HRV. Two of them have not been discovered and physiologically explained yet. Their frequency ranges are 0.21 to 0.31 1/beat with the peak at 0.26 1/beat and 0.25 to 0.5 1/beat with the peak 0.35 1/beat. Despite of differences of the peak frequencies the frequency rages of the factors are overlapped. Therefore, power of spe...

Mukhin, V.

2010-01-01

66

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

LENUS (Irish Health Repository)

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

Moran, D

2014-08-23

67

HEART RATE DURING SLEEP: IMPLICATIONS FOR MONITORING TRAINING STATUS  

Directory of Open Access Journals (Sweden)

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

Miriam R. Waldeck

2003-12-01

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Heart rate analysis in normal subjects of various age groups  

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Full Text Available Abstract Background Analysis of heart rate variation (HRV has become a popular noninvasive tool for assessing the activities of the autonomic nervous system (ANS. HRV analysis is based on the concept that fast fluctuations may specifically reflect changes of sympathetic and vagal activity. It shows that the structure generating the signal is not simply linear, but also involves nonlinear contributions. Linear parameters, Power spectral indice (LF/HF is calculated with nonlinear indices Poincare plot geometry(SD1,SD2, Approximate Entropy (ApEn, Largest Lyapunov Exponent (LLE and Detrended Fluctuation Analysis(DFA. The results show that, with aging the heart rate variability decreases. In this work, the ranges of all linear and nonlinear parameters for four age group normal subjects are presented with an accuracy of more than 89%. As a pre-analysis step, the HRV data is tested for nonlinearity using surrogate data analysis and the results exhibited a significant difference in the ApEn, LLE, SD1/SD2 and DFA parameters of the actual data and the surrogate data. Methods The heart rate is analyzed using the various time domain parameters, frequency domain parameter and nonlinear parameters like Poincare geometry, ApEn, LLE and DFA. Results In this work, the different linear and nonlinear parameters evaluated show a particular range for various cardiac abnormalities. And the results of these were subjected to 't' test with more than 89% confidence interval giving excellent 'p' values in all cases. Conclusions Heart rate variability (HRV signal can be used as a reliable indicator of state of the heart. It becomes less random with the aging(less chaotic. This is evaluated by using various time domain, frequency domain and nonlinear parameters like SD1/SD2, ApEn, LLE ?s and ?l. Different ranges of non-linear parameters for various age groups are presented with 'p' value ? 0.12.

Ping Luk

2004-07-01

69

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)

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General anesthesia suppresses normal heart rate variability in humans  

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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

71

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 ...

Taskina Ali; Shelina Begum; Sultana Ferdousi; Noorzahan Begum,; Sangita Mithun

2011-01-01

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Effects of work stress on ambulatory blood pressure, heart rate, and heart rate variability.  

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Work stress has repeatedly been associated with an increased risk for cardiovascular disease. This study tested whether this relationship could be explained by exaggerated cardiovascular reactivity to work or impaired recovery in leisure time. Vagal tone was assessed as a possible determinant of these work stress effects. Participants included 109 male white-collar workers (age, 47.2+/-5. 3) who were monitored on 2 workdays and 1 nonworkday for ambulatory blood pressure, heart rate, and heart rate variability. Chronic work stress was defined according to Siegrist's model as (1) high imbalance, a combination of high effort and low reward at work, or (2) high overcommitment, an exhaustive work-related coping style indexing the inability to unwind. All findings were adjusted for possible differences in posture and physical activity between the work stress groups. High imbalance was associated with a higher heart rate during work and directly after work, a higher systolic blood pressure during work and leisure time, and a lower 24-hour vagal tone on all 3 measurement days. Overcommitment was not associated with an unfavorable ambulatory profile. Logistic regression analysis revealed that heart rate [odds ratio 1-SD increase 1.95 (95% CI, 1.02 to 3.77)] and vagal tone [odds ratio 1-SD decrease 2.67 (95% CI, 1.24 to 5.75)] were independently associated with incident mild hypertension. Surprisingly, the values during sleep were more predictive for mild hypertension than the values during work. The results from the present study suggest that the detrimental effects of work stress are partly mediated by increased heart rate reactivity to a stressful workday, an increase in systolic blood pressure level, and lower vagal tone. PMID:10775555

Vrijkotte, T G; van Doornen, L J; de Geus, E J

2000-04-01

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Heart rate detection from plantar bioimpedance measurements.  

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In this paper, a novel technique for heart rate measurement on a standing subject is proposed that relies on electrical impedance variations detected by a plantar interface with booth feet, such as those in some bathroom weighting scales for body composition analysis. Heart-related impedance variations in the legs come from arterial blood circulation and are below 500 mOmega. To detect them, we have implemented a system with a gain in excess of 600, and whose fully differential AC input amplifier has a gain of 4.5 and a common-mode rejection ratio (CMRR) higher than 90 dB at 10 kHz. Differential coherent demodulation based on synchronous sampling yields a signal-to-noise ratio (SNR) of about 54 dB . The system sensitivity is 610 mV/Omega. The technique has been demonstrated on 18 volunteers, whose bioimpedance signal and ECG were simultaneously recorded. A Bland-Altman plot shows a mean bias of -0.2 ms between the RR time intervals obtained from these two signals, which is negligible. The technique is simple and user friendly and does not require any additional sensors or electrodes attached to the body, hence no conductive gel or skin preparation. PMID:18334409

Gonzalez-Landaeta, Rafael; Casas, Oscar; Pallàs-Areny, Ramon

2008-03-01

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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

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Relationship between anxiety, heart rate and efficiency of pistol shooting  

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Full Text Available The purpose of this study was to investigate the relationship between anxiety, heart rate and efficiency of pistol shooting. In this study, 291 male volunteers working for the Turkish National Police within the age range of 20-23 years participated. The efficiency of pistol shooting was evaluated by the total points of the bullets which hit the target from 10 metres. The State-Trait Anxiety Inventory (STAI was used to assess anxiety. The “Polar Team2 Pro” device for heart rate was used. Significant differences were found between the sets of participants according to shot accuracy groups for state anxiety level, anxiety variability, average heart rate, maximal heart rate and heart rate changes. The correlation coefficient between the pistol shooting result and change in heart rate, anxiety variability, mean heart rate during shooting, state anxiety and maximal heart rate during shooting was significant. However, there was no significant correlation between shot accuracy and resting heart rate and trait anxiety. Based on the findings, it was concluded that as a result of the higher state anxiety levels, the tremor which is caused by increased heart rate negatively affects the shooting performance in police.

Gürhan Kayihan

2014-06-01

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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

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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

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Erythropoietin, Heart Disease and Global Rate  

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Full Text Available In medicine, the relationship between erythropoietin and heart disease is sometimes mentioned. An attempt to demonstrate connection between erythropoietin and heart failure is very interesting. The attempt is based on the interrelationship among erythropoietin disturbance, anemia and heart disorder. However, the factors that can affect the endemic pattern must be considered

Viroj Wiwanitkit

2013-01-01

79

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

80

Quantitative analysis of heart rate variability  

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In the modern industrialized countries every year several hundred thousands of people die due to sudden cardiac death. The individual risk for this sudden cardiac death cannot be defined precisely by common available, noninvasive diagnostic tools like Holter monitoring, highly amplified ECG and traditional linear analysis of heart rate variability (HRV). Therefore, we apply some rather unconventional methods of nonlinear dynamics to analyze the HRV. Especially, some complexity measures that are based on symbolic dynamics as well as a new measure, the renormalized entropy, detect some abnormalities in the HRV of several patients who have been classified in the low risk group by traditional methods. A combination of these complexity measures with the parameters in the frequency domain seems to be a promising way to get a more precise definition of the individual risk. These findings have to be validated by a representative number of patients.

Kurths, J.; Voss, A.; Saparin, P.; Witt, A.; Kleiner, H. J.; Wessel, N.

1995-03-01

 
 
 
 
81

Elevated resting heart rate is associated with the metabolic syndrome  

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Full Text Available Abstract Background Increased resting heart rate (RHR may be associated with increased cardiovascular morbidity. Our aim was to explore the possibility that increased RHR is associated with the prevalence of the metabolic syndrome (MetS in a sample of apparently healthy individuals and those with cardiovascular risk factors. Methods We performed a cross-sectional analysis in a large sample of apparently healthy individuals who attended a general health screening program and agreed to participate in our survey. We analyzed a sample of 7706 individuals (5106 men and 2600 women with 13.2% of men and 8.9% of the women fulfilling the criteria for the MetS. The participants were divided into quintiles of resting heart rate. Multiple adjusted odds ratio was calculated for having the MetS in each quintile compared to the first. Results The multi-adjusted odds for the presence of the MetS increased gradually from an arbitrarily defined figure of 1.0 in the lowest RHR quintile ( Conclusion Raised resting heart rate is significantly associated with the presence of MetS in a group of apparently healthy individuals and those with an atherothrombotic risk. The strength of this association supports the potential presence of one or more shared pathophysiological mechanisms for both RHR and the MetS.

Saar Nili

2009-10-01

82

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

83

POSTURAL CHANGES IN HEART RATE AND BLOOD PRESSURE WITH AGEING  

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Full Text Available Introduction: The change in arterial blood pressure and heart rate is one of the generally known physiological changes in aging of man. The present study was intended to evaluate BP and HR changes with age. Aim The objective of the study is to know the prevalence of orthostatic hypotension in healthy geriatric subjects. Materials and Methods: The subjects selected are 120 in number with age group 35 to >65 years of both sex and they are categorized into 4 groups based on their age. Group- I: The age of 35-45 years; Group-II: The age of 45-55 years; Group-III: The age of 55-65 Years; Group-IV: The age of >65 years. Blood Pressure is recorded by using manual sphygmomanometer and orthostatic test was conducted in all the subjects. Heart Rate was calculated by using R-R interval by ECG machine. Results: The examination of parameters, body mass index, Heart Rate, systolic and diastolic Blood Pressure during resting, immediate standing, after three minutes of standing i.e., postural variations were estimated for all subjects. The data was analyzed by using descriptive and inferential statistics. Discussion: The findings suggested that the mean SBP and DBP are higher in Group IV compared to Group I which is statistically highly significant. After immediate standing in all the subjects the SBP is decreased and DBP is increased and this variation is variable in different groups. The Heart Rate in all four Groups increases. And this variation is also variable in different groups. Conclusion: This study concluded that BP increases with increase in age due to stiffening of Blood vessels but the postural decrease in SBP in standing from lying down posture was more in elderly. Orthostatic Hypotension was found in only one elderly. So Orthostatic Hypotension was less prevalent in healthy elderly.

K. Pujitha

2014-11-01

84

Effects of different training amplitudes on heart rate and heart rate variability in young rowers.  

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Vaz, MS, Picanço, LM, and Del Vecchio, FB. Effects of different training amplitudes on heart rate and heart rate variability in young rowers. J Strength Cond Res 28(10): 2967-2972, 2014-The aim of this study was to investigate the autonomic nervous system recovery and the psychological response as a result of 3 training amplitudes on heart rate (HR), heart rate variability (HRV), and rate of perceived exertion (RPE) in rowing. Eight young rowers (16.8 ± 1.4 years) performed, in a randomized fashion, 2 sessions of high-intensity interval training, with high and low amplitude and a continuous training (CT) session, with the same exercise duration (10 minutes) and mean intensity (60% of maximal stroke test). The data of HR, HRV, and RPE were collected 5 minutes before, immediately after each session, and 24 hours later. High amplitude promoted higher impact in maximum HR (p ? 0.05) and RPE (p < 0.001) when compared with CT. For the time domain HRV variable, there was a statistically significant difference between moments of rest (pretraining or post 24 hours) and posttraining in all training sessions. Originally, we conclude that training with higher load variation between effort and recovery impacts HRV, HR, and RPE with greater intensity, but the younger rowers were ready for new training sessions 24 hours after either training method. Coaches can use the polarized training method, observing the stimulus nature and time required for recovery, because it may be an adequate strategy for the development of rower's conditioning. PMID:24736775

Vaz, Marcelo S; Picanço, Luan M; Del Vecchio, Fabrício B

2014-10-01

85

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 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

86

Conclusions and recommendations from the symposium, Heart Healthy Omega-3s for Food: Stearidonic Acid (SDA) as a Sustainable Choice.  

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Faculty who had presented at the symposium "Heart Healthy Omega-3s (n-3 fatty acids) for Food: Stearidonic Acid (SDA) as a Sustainable Choice" met and agreed upon conclusions and recommendations that could be made on the basis of evidence provided at the symposium. The participants also submitted manuscripts relating to their topics and these are presented in this supplement. These manuscripts were reviewed and also contributed to the conclusions and recommendations presented herein. The three major objectives of the symposium were to: 1) increase understanding of the current and emerging knowledge regarding the health benefits of (n-3) fatty acids (FA) including a focus on stearidonic acid (SDA) and EPA; 2) evaluate the importance of increasing (n-3) FA consumption in the US and the current challenge of doing so via mainstream foods; and 3) consider the health and food application benefits of SDA as a precursor to EPA and a plant-based sustainable source of highly unsaturated (n-3) FA for mainstream foods. Specific areas for future research were defined and included in the summary and conclusions herein. Overall evidence-based conclusions included: the current evidence provides a strong rationale for increasing (n-3) FA intakes in the US and other populations; current consumption of (n-3) FA in most populations is either insufficient or not efficient at providing adequate tissue levels of the long-chain (n-3) FA EPA and DHA; SDA in soybean oil appears to be a cost-effective and sustainable plant-based source that could contribute to reaching recommended levels of (n-3) FA intake, but more research and surveillance is needed; and adding SDA-enriched soybean oil to foods should be considered as a natural fortification approach to improving (n-3) FA status in the US and other populations. References for these conclusions and recommendations can be found in the articles included in the supplement. PMID:22323767

Deckelbaum, Richard J; Calder, Philip C; Harris, William S; Akoh, Casimir C; Maki, Kevin C; Whelan, Jay; Banz, William J; Kennedy, Eileen

2012-03-01

87

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...

Stolarz, Katarzyna; Staessen, Jan A.; Kuznetsova, Tatiana; Tikhonoff, Vale?rie; State, Doina; Babeanu, Speranta; Casiglia, Edoardo; Fagard, Robert; Kawecka-jaszcz, Kalina; Nikitin, Yuri

2003-01-01

88

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

Science.gov (United States)

Heart rate (HR) variability (HRV; beat-to-beat changes in the R-wave to R-wave interval) has attracted considerable attention during the past 30+ years (PubMed currently lists >17 000 publications). Clinically, a decrease in HRV is correlated to higher morbidity and mortality in diverse conditions, from heart disease to fetal distress. It is usually attributed to fluctuation in cardiac autonomic nerve activity. We calculated HRV parameters from a variety of cardiac preparations (including humans, living animals, Langendorff-perfused heart, and single sinoatrial nodal cell) in diverse species, combining this with data from previously published articles. We show that regardless of conditions, there is a universal exponential decay-like relationship between HRV and HR. Using 2 biophysical models, we develop a theory for this and confirm that HRV is primarily dependent on HR and cannot be used in any simple way to assess autonomic nerve activity to the heart. We suggest that the correlation between a change in HRV and altered morbidity and mortality is substantially attributable to the concurrent change in HR. This calls for re-evaluation of the findings from many articles that have not adjusted properly or at all for HR differences when comparing HRV in multiple circumstances. PMID:25225208

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

2014-12-01

89

Genetic mapping of a new heart rate QTL on chromosome 8 of spontaneously hypertensive rats  

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Full Text Available Abstract Background Tachycardia is commonly observed in hypertensive patients, predominantly mediated by regulatory mechanisms integrated within the autonomic nervous system. The genetic loci and genes associated with increased heart rate in hypertension, however, have not yet been identified. Methods An F2 intercross of Spontaneously Hypertensive Rats (SHR × Brown Norway (BN linkage analysis of quantitative trait loci mapping was utilized to identify candidate genes associated with an increased heart rate in arterial hypertension. Results Basal heart rate in SHR was higher compared to that of normotensive BN rats (365 ± 3 vs. 314 ± 6 bpm, p Conclusion Our data suggest that an influential genetic region located on the rat chromosome 8 contributes to the regulation of heart rate. Candidate genes that have previously been associated with tachycardia and/or hypertension were found within this QTL, strengthening our hypothesis that these genes are, potentially, associated with the increase in heart rate in a hypertension rat model.

Krieger José E

2007-04-01

90

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

91

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

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

Buck, Marilyn M.

92

1/f Scaling in Heart Rate Requires Antagonistic Autonomic Control  

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We present the first systematic evidence for the origins of 1/f-type temporal scaling in human heart rate. The heart rate is regulated by the activity of two branches of the autonomic nervous system: the parasympathetic (PNS) and the sympathetic (SNS) nervous systems. We examine alterations in the scaling property when the balance between PNS and SNS activity is modified, and find that the relative PNS suppression by congestive heart failure results in a substantial increase...

Struzik, Zbigniew R.; Hayano, Junichiro; Sakata, Seiichiro; Kwak, Shin; Yamamoto, Yoshiharu

2004-01-01

93

Heart rate variability in patients with stable angina pectoris  

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The rate and modulation of the heart beat (i.e. heart rate variability; HRV) are controlled by the autonomic nervous system. Cardiac sympathetic activation decreases and parasympathetic increases HRV. Measurements of HRV can be performed in the frequency domain or the time domain; also simple geometric methods are used for time domain measurements. HRV has provided important prognostic information in patients following an acute myocardial infarction and in heart failure pati...

Bjo?rkander, Inge

2009-01-01

94

Sinus versus nonsinus tachycardia in the emergency department: Importance of age and heart rate  

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Full Text Available Abstract Background The emergency department diagnosis of sinus versus nonsinus tachycardia is an important clinical challenge. The objective of this study was to identify subjects with a high prevalence of nonsinus tachycardia. Methods Heart rate and cardiac rhythm were prospective reviewed in 500 consecutive patients with heart rate ? 100 beats/min in a busy emergency department. A predictive model based on age and heart rate was then developed to identify the probability of nonsinus tachycardia. Results As age and heart rate increased, nonsinus tachycardias became more frequent. The probability of nonsinus tachycardia in a subject ? 71 years with heart rate ? 141 beats/minute was 93%, compared to only three percent in a subject ? 50 years with heart rate 100–120 beats/minute. A simple point score system based on age and heart rate helps predict the probability of sinus tachycardia versus nonsinus tachycardia. Conclusion Nonsinus tachycardia is significantly more common than sinus tachycardia in elderly patients in the emergency department. The diagnosis of sinus tachycardia becomes much less likely as age and heart rate increase.

Pedan Alexander

2003-08-01

95

Heart Rate Recovery During a College Basketball Game.  

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It has been established by several investigators that heart rate is a good indicator of the energy expenditure for a given work task. Heart rate has also been shown to give quicker response to emotional involvement than do other measures of physiological ...

J. D. Ramsey, M. M. Ayoub, R. A. Dudek, H. S. Edgar

1970-01-01

96

Effect of Age and Other Factors on Maximal Heart Rate.  

Science.gov (United States)

To reduce confusion regarding reported effects of age on maximal exercise heart rate, a comprehensive review of the relevant English literature was conducted. Data on maximal heart rate after exercising with a bicycle, a treadmill, and after swimming were analyzed with regard to physical fitness and to age, sex, and racial differences. (Authors/PP)

Londeree, Ben R.; Moeschberger, Melvin L.

1982-01-01

97

Using Target Heart-Rate Zones in Your Class  

Science.gov (United States)

Should teachers teach the calculation of target heart rate to students? And when is it appropriate to engage students in the attainment of these heart rates during physical education class activities? The answers to these questions are not easy. One might be tempted to state a simple yes or no and to identify a specific age to begin using training…

Gilbert, Jennie A.

2005-01-01

98

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

Directory of Open Access Journals (Sweden)

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

99

Heart rate dynamics during a treadmill cardiopulmonary exercise test in optimized beta-blocked heart failure patients  

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BACKGROUND: Calculating the maximum heart rate for age is one method to characterize the maximum effort of an individual. Although this method is commonly used, little is known about heart rate dynamics in optimized beta-blocked heart failure patients. AIM: The aim of this study was to evaluate heart rate dynamics (basal, peak and % heart rate increase) in optimized beta-blocked heart failure patients compared to sedentary, normal individuals (controls) during a treadmill cardiopulmonary exer...

Vitor Oliveira Carvalho; Guilherme Veiga Guimarães; Edimar Alcides Bocchi

2008-01-01

100

Heart rate values for beaver, mink and muskrat.  

Science.gov (United States)

1. Implanted ECG transmitters were used to determine heart rates for several activities of beaver (Castor canadensis), mink (Mustela vison), and muskrat (Ondatra zibethicus) under free-ranging laboratory conditions within an aquatic tank. 2. All three species exhibited bradycardia when diving but mink heart rates returned to pre-dive levels if the dive lasted greater than 30 sec. 3. Heart rates for all other behaviours were significantly (P less than 0.05) higher than for diving and averaged about 120/min (beaver), 265/min (mink) and 240/min (muskrat). 4. Mink heart rate values were higher than would be expected based on general energetic equations if we assume heart rate to be reflective of energy costs. This was considered to be a function of this species' fusiform body shape. PMID:6128113

Gilbert, F F; Gofton, N

1982-01-01

 
 
 
 
101

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

102

Learning by Heart: Students Use Heart Rate Patterns To Identify Nervous System Imbalances.  

Science.gov (United States)

Introduces a science unit on heart rate variability (HVR) patterns. Uses spectral analysis to determine the effects of environmental stimulants such as music and emotional stress on heart rate. Observes relaxation techniques and their effects on the autonomous nervous system. (Contains 12 references.) (YDS)

Ackerly, Spafford C.

2001-01-01

103

Heart rate recovery index in patients with psoriasis.  

Science.gov (United States)

Objectives: In clinical practice, autonomic functions are indirectly investigated with heart rate recovery (HRR) index measurements. Our aim was to evaluate the HRR index in patients with psoriasis, which is a systemic inflammatory disease. Study design: The study population included 39 psoriasis patients (18 female, mean age 48±15 years) and 40 control group (18 female, mean age 44±9 years) healthy individuals. The severity of psoriasis was calculated using the psoriasis area and severity index (PASI). None of the study patients had a PASI score >50. All of the participants underwent treadmill exercise testing using the Bruce protocol. Results: According to basic clinical and demographic characteristics, both groups were similar with regard to age, body mass index, and fasting glucose and cholesterol levels. No significant differences were observed in the systolic or diastolic blood pressures or resting heart rates between the two groups. All patients and control-group participants had sinus rhythm and normal 12-lead ECG results at rest. All subjects completed the exercise tests to exhaustion without rhythm abnormalities, ischemic changes, or other complications. The maximal heart rate and metabolic equivalents achieved during the exercise stress test (EST) were similar in the psoriasis and control group (163±16 vs. 170±16, p=0.07; 9.8±0.9 vs. 10.1±1.0, p=0.24, respectively). The 1st, 3rd, and 5th minute HRR indices of patients with psoriasis were similar to those of the control group (HRR1: 30±12, 32±18, p=0.71; HRR3: 57±13, 64±17, p=0.10; HRR5: 64±15, 68±16, p=0.46, respectively). Conclusion: The HRR index, which is calculated by an EST and associated with autonomic nervous system function, is not effected in mild to moderate psoriasis patients. PMID:23187431

Bulur, Serkan; Turan, Hakan; Aslanta?, Yusuf; Gürlevik, Zehra; Oz?ahin, Mustafa; Ankaral?, Handan; Ekinözü, Ismail; Ca?lar, Sabri Onur; Ozhan, Hakan

2012-09-01

104

Relation between heart rate, heart rhythm, and reverse left ventricular remodelling in response to carvedilol in patients with chronic heart failure: a single centre, observational study  

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Objective: To determine whether the process of reverse left ventricular remodelling in response to carvedilol is dependent on baseline heart rate (BHR), heart rhythm, or heart rate reduction (HRR) in response to carvedilol.

Arnold, R. H.; Kotlyar, E.; Hayward, C.; Keogh, A. M.; Macdonald, P. S.

2003-01-01

105

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

Directory of Open Access Journals (Sweden)

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

106

Operant conditioning of heart rate in curarized rats: hemodynamic changes.  

Science.gov (United States)

Three groups of curarized rats were subjected to operant heart rate conditioning with use of a shock-avoidance procedure while cardiac output, mean arterial pressure, and total peripheral resistance were measured. Heart rate changes in the control group remained constant during the entire 90-min experimental period, while cardiac output decreased significantly. Those rats that were reinforced for increasing their heart rate had a small but statistically significant increase in heart rate, but cardiac output decreased to approximately the same extent as in the control group. The group reinforced for decreasing their heart rate demonstrated a large, significant decrease in heart rate and an even larger drop in cardiac output, which was significantly greater than that of either of the other two groups. Operant conditioning of a single facet of the cardiovascular system resulted in significantly larger changes in other cardiovascular parameters, which may have been partly masked by the physiological effects of d-tubocurarine. Therefore, only when these other measures of cardiovascular function are taken into consideration can interpretation of operant heart rate conditioning become meaningful. PMID:1115251

Gliner, J A; Horvath, S M; Wolfe, R R

1975-03-01

107

Temperature to heart rate relationship in the neonate  

Directory of Open Access Journals (Sweden)

Full Text Available In neonatal intensive care, measurement of heart rate is part of every clinical examination and it is used for monitoring hemodynamic status. However, it is influenced by some exogenous and endogenous factors, such as medication, pain, and stress. (1 Similarly, an increased heart rate is a normal physiological response to fever. Heart rate is known to increase by 10 beats per minute (bpm per degree centigrade increase in body temperature in children. (2 In order to allow physicians to identify patients who have a higher heart rate than would be expected for a given level of temperature, Thompson et al. (3 created temperature specific heart rate centile charts adaptable to children from three months to ten years. Very few data exist on the relationship of temperature and heart rate in younger infants. The only study on this topic so far was performed in an emergency department that included infants up to the age of 12 months, where they found no linear correlation between fever and heart rate in the group of infants younger than two months. (4 To our knowledge no studies have ever addressed this issue in newborns.

Nora Hofer

2012-04-01

108

Heart rate variability. Frequency domain analysis.  

Science.gov (United States)

Experience with frequency domain analysis over the past two decades strongly suggests that it represents a unique, noninvasive tool for achieving a more precise assessment of autonomic function in both the experimental and clinical settings. Available studies indicate that the significance of the HF component is far better understood than that of the lower frequency components. In general, it is considered to reflect vagal activity, and because it is readily manipulated pharmacologically, is used as a an index of that activity. However, some caution is required because this parameter also is strongly influenced by the degree of coupling between respiration and heart rate, which, in turn, reflects the intensity of the respiratory effort as well as of parasympathetic activity. Respiratory pattern also can significantly influence HF power. The use of controlled breathing minimizes these problems, improves reproducibility of test findings, and also facilitates quantitative comparisons. The situation with respect to LF power is more complicated because it is modulated by both sympathetic and parasympathetic outflows (see previous discussion) as well as by other factors, including baroreceptor activity. Therefore, LF analysis per se cannot afford a precise delineation of the state of sympathetic activation. Determinations of the LF/HF ratio, an index of sympathovagal balance both under control conditions and in conjunction with interventions that maximize sympathetic and parasympathetic activity, provide additional insights, as do correlations between spectral activity and direct nerve recordings, plasma norepinephrine concentrations, and radionuclide imaging of adrenergic nerves. Renewed interest has recently been evinced in frequencies lower than 0.04 Hz in view of reports that the VLF portion of the spectrum (0.01-0.04 Hz) reflects a purer form of sympathetic activity than does the LF band. Despite the potential applicability to clinical problems, only very little is known about the physiologic basis of the VLF and ULF bands. Further study is required. However, it is important to note that meaningful determinations of VLF and ULF power may be difficult because decreases in frequency to such low levels are associated with an increasing propensity to violate the rules governing power spectral determinations (see previous discussion and appendix), violations that diminish reliability despite the most sophisticated preprocessing. It is also noteworthy that the reliability of spectral power determinations diminishes with decreases in the power of the signal and of the signal-to-noise ratio.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:1504981

Ori, Z; Monir, G; Weiss, J; Sayhouni, X; Singer, D H

1992-08-01

109

Assessment of heart rate as a predictor of ventilation.  

Science.gov (United States)

The rate of ventilation and route of breathing (i.e., nasal versus oronasal) are potential determinants of pollutant doses to target sites in the lung. However, the lack of accurate methods for ambulatory measurement of ventilation has hindered estimation of exposure and dose in freely ranging individuals, complicating the interpretation of the relationships among exposure, dose, and response in epidemiological studies. The goal of this project was to develop and validate a method of monitoring ventilation for large-scale epidemiologic investigations. We estimated ventilation for individual subjects from ambulatory heart rate monitoring, using the relationship between ventilation and heart rate that had been obtained during exercise testing. Fifty-eight subjects participated in the study, which included healthy adults and children, and subjects with lung and heart disease. Subjects performed cycle exercise and tasks involving lifting and vacuuming. Work loads of progressive and variable order were used in the testing. Conventional methods were used to measure heart rate and total ventilation, and a sampling mask was developed to measure the partitioning of breathing between oral and nasal routes. The minute ventilation-heart rate relation was evaluated under steady-state and varying work loads. In a second phase, subjects wore wristwatch monitors that recorded their heart rates, minute by minute, throughout the day. Subjects recorded activities, locations, and levels of exertion. Two 16-hour monitoring periods were obtained from each subject. The laboratory findings documented considerable intersubject variability in the minute ventilation-heart rate relation with a two- to five-fold range in the coefficients describing the change in ventilation relative to heart rate. This variation implies that individual testing is required to derive accurate predictive equations. Minute ventilation-heart rate regressions for the maximal progressive exercise test and for the test with a nonprogressive submaximal work load sequence were comparable, indicating that varying the sequence of work loads does not substantially affect the minute ventilation-to-heart rate ratio. During upper body work (e.g., lifting), the minute ventilation-to-heart rate ratio was one-third greater than during lower body exercise. Diverse patterns of partitioning breathing between oral and nasal routes were observed with increasing oral ventilation in most subjects as work load increased. In the field, heart rate and activity patterns were monitored successfully in adults and children with low rates of instrument failure and noncompliance.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:8216970

Samet, J M; Lambert, W E; James, D S; Mermier, C M; Chick, T W

1993-05-01

110

Visual discrimination learning in dwarf goats and associated changes in heart rate and heart rate variability.  

Science.gov (United States)

We studied visual discrimination learning in a group of Nigerian dwarf goats using a computer-based learning device which was integrated in the animals' home pen. We conducted three consecutive learning tasks (T1, T2 and T3), each of which lasted for 13 days. In each task, a different set of four visual stimuli was presented on a computer screen in a four-choice design. Predefined sequences of stimulus combinations were presented in a pseudorandom order. Animals were rewarded with drinking water when they chose the positive stimulus by pressing a button next to it. Noninvasive measurements of goats' heartbeat intervals were carried out on the first and the last 2 days of each learning task. We analysed heart rate (HR) and heart rate variability (HRV) of resting animals to study sustained physiological effects related to general learning challenge rather than acute excitement during an actual learning session. The number of trials to reach the learning criterion was 1000 in T1, when visual stimuli were presented to the goats for the first time, but decreased to 210 in T2 and 240 in T3, respectively. A stable plateau of correct choices between 70% and 80% was reached on Day 10 in T1, on Day 8 in T2 and on Day 6 in T3. We found a significant influence of the task and of the interaction between task and day on learning success. Whereas HR increased throughout T1, this relationship was inverted in T2 and T3, indicating different effects on the HR depending on how familiar goats were with the learning task. We found a significant influence of the task and the interaction between task and time within the task on HRV parameters, indicating changes of vagal activity at the heart. The results suggest that changes in HR related to learning were predominantly caused by a withdrawal of vagal activity at the heart. With regard to nonlinear processes in heartbeat regulation, increased deterministic shares of HRV indicated that the animals did not really relax until the end of T3. Comparing changes of HR and HRV in T3 and in a subsequent postexperiment (PE), we assume a positive effect of such cognitive challenges once the task had been learned by the animals. PMID:15327907

Langbein, Jan; Nürnberg, G; Manteuffel, G

2004-09-30

111

Effect of heart rate on hemodynamics in mitral stenosis  

International Nuclear Information System (INIS)

Objective: To assess the effect of heart rate (HR) on haemodynamic parameters in patients with Mitral Stenosis (MS). Methodology: The study was conducted at Cardiology department, Lady Reading Hospital, Peshawar from November 2010 to April 2011. Patients with MS, regardless of severity, were included. Patients with severe heart failure, other valvular or structural heart disease were excluded. Echocardiographic parameters were recorded at slow and fast HR. Patients with tachycardia were given a-blockers and patients with bradycardia were given parenteral Atropine. Results: A total of 60 patients were included, females were 57 (78%). Mean age was 31+- 9 years. Mean slow and fast HR was 77+-12 bpm and 110+-13 bpm, respectively. Peak mitral valve gradient (PMVG) slow vs. fast HR was 12.8+-4.80 and 14.93+-7.18 mm Hg (p=0.000). Mean mitral valve gradient (MMVG) at slow vs. fast HR was 6.62+-3.29 and 8.15+-4.88 mm of Hg (p=0.000). E pulse Doppler (E) at slow vs. fast HR was 168+-35 and 181+-40 cm/s (p=0.013), / while E tissue Doppler (E ) velocity was 10.47+-2.81 and 10.97+-2.38 cm/s/ (P=0.098), respectively. E/E ratio for slow and fast HR was 17+-5.63 vs.17+-5.41 (P=0.792). Right ventricular systolic pressure (RVSP) at slow vs. fast HR was 44+-16 vs.49+-17.05 mm of Hg (P=0.001). The above parameters had insignificant change with the HR when there was accompanying more than mild MR. Conclusion: Slowing HR in patients with MS significantly decreased PMVG, MMVG and RVSP. LV function did not change significantly with HR. Rate control drugs may be used in preference to improve symptoms in moderate and severe MS. (author)

112

Phase Transition in a Healthy Human Heart Rate  

Science.gov (United States)

A healthy human heart rate displays complex fluctuations which share characteristics of physical systems in a critical state. We demonstrate that the human heart rate in healthy individuals undergoes a dramatic breakdown of criticality characteristics, reminiscent of continuous second order phase transitions. By studying the germane determinants, we show that the hallmark of criticality—highly correlated fluctuations—is observed only during usual daily activity, and a breakdown of these characteristics occurs in prolonged, strenuous exercise and sleep. This finding is the first reported discovery of the dynamical phase transition phenomenon in a biological control system and will be a key to understanding the heart rate control system in health and disease.

Kiyono, Ken; Struzik, Zbigniew R.; Aoyagi, Naoko; Togo, Fumiharu; Yamamoto, Yoshiharu

2005-07-01

113

"Heart rate-dependent" electrocardiographic diagnosis of left ventricular hypertrophy.  

Science.gov (United States)

A case is presented revealing the common phenomenon of heart rate-dependent diagnosis of electrocardiographic (ECG) diagnosis of left ventricular hypertrophy (LVH), which consists of satisfaction of LVH criteria only at faster rates whereas ECGs with a slow heart rate do not satisfy such criteria. The mechanism of the phenomenon has been attributed to the tachycardia-mediated underfilling of the left ventricle bringing the electrical "centroid" of the heart closer to the recording electrodes, which results in augmentation of the amplitude of QRS complexes, particularly in leads V2-V4. PMID:22519574

Madias, John E

2013-05-01

114

Heart rate turbulence as risk-predictor after myocardial infarction  

Directory of Open Access Journals (Sweden)

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

115

Heart rates in the captive, free-ranging beaver.  

Science.gov (United States)

1. Heart rates of beaver (Castor canadensis) under free-ranging captive conditions for active behaviors and resting in water (approximately 121 beats/min) were significantly (P less than 0.01) higher than for resting on land (100 beats/min). 2. Although no transient recovery tachycardia was evident in swimming heart rates following diving, average swimming heart rates were higher (127 beats/min) after diving than after other precursor behaviors (123 beats/min). 3. Beaver exhibited bradycardia when sleeping (75 beats/min), diving (61 beats/min), and when threatened on land (57 beats/min). 4. The respiratory sinus arrhythmia indicated a respiratory rate of 15 breaths/min. 5. Cold temperatures (approximately 0 degree C) elicited higher heart rates than did warmer temperatures (approximately 20 degrees C) in active, non-diving behaviors (P less than 0.05). PMID:2906827

Swain, U G; Gilbert, F F; Robinette, J D

1988-01-01

116

Design and Development of a Heart Rate Measuring Device using Fingertip  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

117

Heart Rate Variability Measures and Models  

CERN Document Server

We focus on various measures of the fluctuations of the sequence of intervals between beats of the human heart, and how such fluctuations can be used to assess the presence or likelihood of cardiovascular disease. We examine sixteen such measures and their suitability for correctly classifying heartbeat records of various lengths as normal or revealing the presence of cardiac dysfunction, particularly congestive heart failure. Using receiver-operating-characteristic analysis we demonstrate that scale-dependent measures prove substantially superior to scale-independent ones. The wavelet-transform standard deviation at a scale near 32 heartbeat intervals, and its spectral counterpart near 1/32 cycles/interval, turn out to provide reliable results using heartbeat records just minutes long. We further establish for all subjects that the human heartbeat has an underlying stochastic origin rather than arising from a chaotic attractor. Finally, we develop a mathematical point process that emulates the human heartbea...

Teich, M C; Jost, B M; Vibe-Rheymer, K; Heneghan, C; Teich, Malvin C.; Lowen, Steven B.; Jost, Bradley M.; Vibe-Rheymer, Karin; Heneghan, Conor

2001-01-01

118

Prediction of heart rate response to conclusion of the spontaneous breathing trial by fluctuation dissipation theory  

International Nuclear Information System (INIS)

The non-equilibrium fluctuation dissipation theorem is applied to predict how critically ill patients respond to treatment, based upon data currently collected by standard hospital monitoring devices. This framework is demonstrated on a common procedure in critical care: the spontaneous breathing trial. It is shown that the responses of groups of similar patients to the spontaneous breathing trial can be predicted by the non-equilibrium fluctuation dissipation approach. This mathematical framework, when fully formed and applied to other clinical interventions, may serve as part of the basis for personalized critical care. (paper)

119

Genome-wide association study of electrocardiographic and heart rate variability traits: the Framingham Heart Study  

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Abstract Background Heritable electrocardiographic (ECG) and heart rate variability (HRV) measures, reflecting pacemaking, conduction, repolarization and autonomic function in the heart have been associated with risks for cardiac arrhythmias. Whereas several rare monogenic conditions with extreme phenotypes have been noted, few common genetic factors contributing to interindividual variability in ECG and HRV measures have been identified. We report the results of a community-...

Guo Chao-Yu; Newton-Cheh Christopher; Wang Thomas J; Larson Martin G

2007-01-01

120

Wine drinking is associated with increased heart rate variability in women with coronary heart disease  

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Objective: To test the hypothesis that alcohol consumption is positively related to heart rate variability (HRV) in women with coronary heart disease (CHD) and therefore that cardiac autonomic activity is potentially implicated in the mediation of the favourable effects of moderate drinking.

Janszky, I.; Ericson, M.; Blom, M.; Georgiades, A.; Magnusson, J-o; Alinagizadeh, H.; Ahnve, S.

2005-01-01

 
 
 
 
121

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. PMID:24838895

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

2014-01-01

122

Recurrence Plots of Heart Rate Signals during Meditation  

Directory of Open Access Journals (Sweden)

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

123

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)

124

Maximal oxygen intake estimated from submaximal heart rate.  

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This study investigated the predictability of maximal oxygen intake from three different submaximal heart rates assessed during an initial and follow-up ride on a cycle ergometer. Twenty-four healthy male subjects performed workloads of 600, 750, and 900 kpm's for six minutes on each of two visits to the laboratory. Analysis of variance for a randomised complete blocks design, with subjects constituting blocks, was used to analyse heart rate, estimated maximal oxygen intake, and residual esti...

Dotson, C. O.; Caprarola, M. A.

1984-01-01

125

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

126

Assessing resting heart rate in adolescents: determinants and correlates.  

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The aim of this study was to evaluate the distribution of resting heart rate and its biological and environmental determinants in adolescents. The study was cross- sectional and the population consisted of 2230 children and adolescents, age range 12-18 years, enrolled randomly from state schools in Turin, Italy. In all participants the following parameters were evaluated: heart rate, blood pressure (BP), weight, height, degree of sexual development, physical activity, parental socio-cultural ...

Veglio, Franco; Mulatero, Paolo

2002-01-01

127

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

128

Effect of immersion, submersion, and scuba diving on heart rate variability  

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Background—Heart rate variability (HRV) describes the cyclic variations in heart rate and offers a non-invasive tool for investigating the modulatory effects of neural mechanisms elicited by the autonomic nervous system on intrinsic heart rate.

Schipke, J.; Pelzer, M.

2001-01-01

129

DETECTING CONGESTIVE HEART FAILURE USING HEART RATE SEQUENTIAL TREND ANALYSIS PLOT  

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Full Text Available Heart rate variability analysis is gaining acceptance as a potential non-invasive means of autonomic nervous system assessment in research as well as clinical domains. In this study, a nonlinear analysis method is developed to detect congestive heart failure. The data obtained from an online and widely used public database (i.e., MIT/BIH physionet database, is used for testing the performance of the method. The method developed is based on the sequential trend analysis plot of heart rate variability and correlates well with the characteristic autonomic nervous system regulations in congestive heart failure. The proposed method can be used for screening as well as diagnosing the heart failure patients. The algorithm is computationally simple and can be implemented in a real time processing hardware. This method classifies 31 out of 32 subjects and has the highest discrimination power in terms of sensitivity, specificity and accuracy.

SRINIVAS KUNTAMALLA,

2010-12-01

130

Heart rate: a prognostic factor and therapeutic target in chronic heart failure. The distinct roles of drugs with heart rate-lowering properties.  

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Heart rate not only predicts outcome but may also be a therapeutic target in patients with chronic heart failure. Several classes of pharmacological agents can be used to modulate heart rate, including beta-blockers, ivabradine, digoxin, amiodarone, and verapamil. Choice of agent will depend on heart rhythm, co-morbidities, and disease phenotype. Beneficial and harmful interactions may also exist. The aim of this paper is to summarize the current body of knowledge regarding the relevance of heart rate as a prognostic factor (risk marker) and particularly as a therapeutic target (risk factor) in patients with chronic heart failure, with a special focus on ivabradine, a novel agent that is currently the only available purely bradycardic agent. PMID:23928650

Dobre, Daniela; Borer, Jeffrey S; Fox, Kim; Swedberg, Karl; Adams, Kirkwood F; Cleland, John G F; Cohen-Solal, Alain; Gheorghiade, Mihai; Gueyffier, Francois; O'Connor, Christopher M; Fiuzat, Mona; Patak, Athul; Piña, Ileana L; Rosano, Giuseppe; Sabbah, Hani N; Tavazzi, Luigi; Zannad, Faiez

2014-01-01

131

The heart field effect: Synchronization of healer-subject heart rates in energy therapy.  

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Recent health research has focused on subtle energy and vibrational frequency as key components of health and healing. In particular, intentional direction of bioenergy is receiving increasing scientific attention. This study investigates the effect of the healer's electromagnetic (EM) heart field upon subjects during energy healing as measured by synchronization of heart rates and scores on a Subjective Units of Distress (SUD) scale and a Profile of Mood States (POMS) inventory. A nonequivalent pretest-posttest design was used based on heart rate comparisons between healer and subject and correlated with pre-and posttest SUD and POMS scores. Subjects included those who sat within the 3- to 4-foot "strong" range of the independent variable, the healer's heart field, while performing self-application of WHEE (the wholistic hybrid derived from EMDR [eye movement desensitization and reprocessing], and EFT [emotional freedom technique]), a meridian-based tapping technique (n=50); and those who performed the same process beyond the 15- to 18-foot range of the healer's EM heart field (n=41). The dependent variables were heart rate, SUD, and POMS inventory. All subjects completed these measures within 1 hour. Study results showed statistically significant heart-rate synchronization with the intervention population. In addition, SUD and POMS scores demonstrated considerably more improvement than in the control population, indicating additional benefit beyond the meridian-based therapies, such as WHEE, alone. Additional findings and future research recommendations are presented in this article. PMID:20664147

Bair, Christine Caldwell

2008-01-01

132

Heart rate, heart rate variability and behaviour of horses during air transport.  

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Heart rate (HR), HR variability (HRV) and behaviour score (BS) of nine horses were evaluated during an eight-hour air transport between The Netherlands and New York. HR and HRV parameters were calculated every five minutes during the air transport. Compared with transit (40±3), mean HRs were higher during loading into the jet stall (67±21, P<0.001), loading into the aircraft (47±6, P=0.011), taxiing (50±8, P=0.001), and during periods of in-flight turbulence (46±7, P=0.017). During the flight, individual horses showed differences in mean HR (P=0.005) and peak HR (P<0.001). By contrast with HR data, HRV data did not differ between stages or horses. BS was highest during turbulence (3.2±0.4). However, behaviour did not always correspond with HR measurements: the least responsive horse had the highest HR. Loading into the jet stall caused the highest increase in HR and was considered the most stressful event. During transit, HR was generally comparable with resting rates. Previous studies have shown that loading and transporting by road caused more elevation in HR than during loading and transporting by air. HRV data were not found to be useful, and caution is needed when interpreting HRV data. Not every horse exhibited stress through visible (evasive) behaviour, and HR measurements may provide an additional tool to assess stress in horses. PMID:23143989

Munsters, C C B M; de Gooijer, J-W; van den Broek, J; van Oldruitenborgh-Oosterbaan, M M Sloet

2013-01-01

133

Cuff inflation during ambulatory blood pressure monitoring and heart rate  

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

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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

135

Estimating oxygen consumption from heart rate and heart rate variability without individual calibration.  

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Heart rate (HR) as an estimator of oxygen consumption (VO(2) ) usually requires HR to be individually calibrated in a separate test. This study examined the validity of a new HR - and HR variability-based method (Firstbeat PRO heartbeat analysis software) in the estimation of VO(2) in real-life tasks. The method takes into account the respiration rate determined from HR variability and the differences in the on/off dynamics of HR and VO(2) , and no calibration tests are needed. Ten men and nine women performed 25 tasks representing different types of daily activities. Portable devices were used to measure R-to-R intervals (ECG), VO(2) and respiration rate. In pooled regression analysis, the estimated VO(2) accounted for 87% of the variability in the actual VO(2) , SEE 3·5 ml min(-1) kg(-1) (1 MET). At group level, the method underestimated slightly the measured VO(2) (mean difference - 1·5 ml min(-1) kg(-1) or - 0·4 METs). Some of the values at low exercise intensities were markedly underestimated, but the agreement was better during light and heavy activities. The limits of agreement for the data were from -8·4 to 5·4 ml min(-1) kg(-1) or from -2·4 to 1·5 METs. At individual level, the average deviations of the predicted VO(2) ranged from -1·0 to 0·6 METs and R(2) from 0·77 to 0·94, respectively. The present data indicate that the prediction method may be considered sufficiently accurate to determine the average VO(2) in field use, but it does not allow precise estimation of VO(2) . PMID:21672133

Smolander, Juhani; Ajoviita, Marjo; Juuti, Tanja; Nummela, Ari; Rusko, Heikki

2011-07-01

136

The relationship between heart rate reserve and oxygen uptake reserve in heart failure patients on optimized and non-optimized beta-blocker therapy  

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Full Text Available BACKGROUND: The relationship between the percentage of oxygen consumption reserve and percentage of heart rate reserve in heart failure patients either on non-optimized or off beta-blocker therapy is known to be unreliable. The aim of this study was to evaluate the relationship between the percentage of oxygen consumption reserve and percentage of heart rate reserve in heart failure patients receiving optimized and non-optimized beta-blocker treatment during a treadmill cardiopulmonary exercise test. METHODS: A total of 27 sedentary heart failure patients (86% male, 50±12 years on optimized beta-blocker therapy with a left ventricle ejection fraction of 33±8% and 35 sedentary non-optimized heart failure patients (75% male, 47±10 years with a left ventricle ejection fraction of 30±10% underwent the treadmill cardiopulmonary exercise test (Naughton protocol. Resting and peak effort values of both the percentage of oxygen consumption reserve and percentage of heart rate reserve were, by definition, 0 and 100, respectively. RESULTS: The heart rate slope for the non-optimized group was derived from the points 0.949±0.088 (0 intercept and 1.055±0.128 (1 intercept, p<0.0001. The heart rate slope for the optimized group was derived from the points 1.026±0.108 (0 intercept and 1.012±0.108 (1 intercept, p=0.47. Regression linear plots for the heart rate slope for each patient in the non-optimized and optimized groups revealed a slope of 0.986 (almost perfect for the optimized group, but the regression analysis for the non-optimized group was 0.030 (far from perfect, which occurs at 1. CONCLUSION: The relationship between the percentage of oxygen consumption reserve and percentage of heart rate reserve in patients on optimized beta-blocker therapy was reliable, but this relationship was unreliable in non-optimized heart failure patients.

Vitor Oliveira Carvalho

2008-01-01

137

Physiological control of intraaorta pump based on heart rate.  

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Because of the special structures of intraaorta pump, the pressure and blood flow sensors cannot be implanted in the blood pump. Moreover, the cardiovascular pump is a very complex system that has no accurate model but much uncertainty and disturbance. Hence, the conventional control algorithm cannot achieve good performance. To overcome this problem, on one hand, a cardiovascular pump model is established. The heart rate in this model is chosen as a controlled variable that is a nonlinear function of the mean arterial pressure. On the other hand, a fuzzy logic feedback control algorithm, which maintains the actual heart rate tracking the desired heart rate, is designed. Computer simulations are performed to verify the robustness and dynamic characters of the controller. The simulation results demonstrate that the controller can maintain the actual heart rate tracking the desired one without static error. When the desired heart rate changed from 100 to 80 bpm, the settling time is <10 seconds. When the peripheral resistance increases from 1.0 to 0.7 mm Hg/ml, the settling time is <10 seconds. PMID:21307771

Gao, Bin; Nie, Li Ya; Chang, Yu; Zeng, Yi

2011-01-01

138

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

139

Central effects of synthesized dihydropyridine derivatives and nifedipine on systolic blood pressure and heart rate of rats  

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Conclusion: Novel dihydropyridine derivatives can possess more potent and stable in-hibitory effects on systolic blood pressure and heart rate, and some part of these properties at least, can be attributed to their direct inhibitory effects on brain neurons.

Azam Bakhtiarian

2014-03-01

140

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

 
 
 
 
141

Assessment of heart rate variability from speech analysis.  

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In this paper, various methods of heart beat variability assessment from speech analysis have been presented. Heart rate variability (HRV) is a physiological phenomenon where the time interval between heart beats varies. It is measured by the variation in the beat-to-beat interval. The present work deals with the HRV detection from speech parameters. RR-cycle detects one heart beat. Continuous monitoring of electrocardiograph for a span of time can provide HRV. More than 250 samples of normal informants as well as heart patients with enlarged heart have been collected during the four years of research work. The regular ECG and speech samples of the patient have been collected and analyzed. Further they had compared with the parameters of a normal healthy informant. Speech samples were collected through a microphone and subjected to be digitized. The required speech segmental have been extracted and analyzed through a DSP tool, PRAAT. ECG sample has been recorded through an ECG machine. A technique of HRV detection from speech analysis has been presented in this paper. The HRV detection from speech can be a very helpful tool in monitoring the functioning of human heart. PMID:25236132

Deshpande, Nivedita; Thakur, Kavita; Zadgaonkar, Arun S

2014-04-01

142

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

143

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

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Abstract Background Heart rate variability (HRV) is known to be impaired in patients with congestive heart failure (CHF). Time-domain analysis of ECG signals traditionally relies heavily on linear indices of an essentially non-linear phenomenon. Poincaré plots are commonly used to study non-linear behavior of physiologic signals. Lagged Poincaré plots incorporate autocovariance information and analysis of Poincaré plots for various lags can provide interesting insights int...

Smith Michael L; Thakre Tushar P

2006-01-01

144

Deterioration of Heart Rate Recovery Index in Patients with Non-Alcoholic Fatty Liver Disease (NAFLD)  

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Background Non-alcoholic fatty liver disease (NAFLD) has been considered as a benign disease often associated with central obesity and insulin resistance and, in general, with factors of the metabolic syndrome. Heart rate recovery after exercise is a function of vagal reactivation, and its impairment is an independent prognostic indicator for cardiovascular and all-cause mortality. The aim of our study was to evaluate the heart rate recovery index in patients with NAFLD. Material/Methods The study population included 59 patients with NAFLD (mean age=42.3±9.3 years) and 22 healthy subjects as controls (mean age=40.7±6.5 years). Basal electrocardiography, echocardiography, and treadmill exercise testing were performed on all patients and controls. The heart rate recovery index was defined as the reduction in the heart rate from the rate at peak exercise to the rate at the 1st minute (HRR1), 2nd minute (HRR2), 3rd minute (HRR3), and 5th minute (HRR5) after stopping exercise stress testing. Results There were significant differences in HRR1 and HRR2 indices between patients with ED and the control group (19.9±8.2 vs. 34.1±9.6; pMETs; p=0.001) among the patients with NAFLD. Conclusions The heart rate recovery index is deteriorated in patients with NAFLD. When the prognostic significance of the heart rate recovery index is considered, these results may help explain the increased occurrence of cardiac death. It points to the importance of the heart rate recovery index in the identification of high-risk patients. PMID:25168159

Ozveren, Olcay; Dogdu, Orhan; Sengul, Cihan; Cinar, Veysel; Eroglu, Elif; Kucukdurmaz, Zekeriya; Degertekin, Muzaffer

2014-01-01

145

Exaggerated heart rate oscillations during two meditation techniques.  

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We report extremely prominent heart rate oscillations associated with slow breathing during specific traditional forms of Chinese Chi and Kundalini Yoga meditation techniques in healthy young adults. We applied both spectral analysis and a novel analytic technique based on the Hilbert transform to quantify these heart rate dynamics. The amplitude of these oscillations during meditation was significantly greater than in the pre-meditation control state and also in three non-meditation control groups: i) elite athletes during sleep, ii) healthy young adults during metronomic breathing, and iii) healthy young adults during spontaneous nocturnal breathing. This finding, along with the marked variability of the beat-to-beat heart rate dynamics during such profound meditative states, challenges the notion of meditation as only an autonomically quiescent state. PMID:10454297

Peng, C K; Mietus, J E; Liu, Y; Khalsa, G; Douglas, P S; Benson, H; Goldberger, A L

1999-07-31

146

Heart rate variability in patients being treated for Dengue viral infection: New insights from mathematical correction of heart rate  

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Full Text Available Introduction: Severe dengue hemorrhagic fever (DHF is a viral infection that acts to increase permeability of capillaries, resulting in internal hemorrhage. Linear frequency domain Fourier spectral analysis represents the most published noninvasive tool for diagnosing and assessing health status via calculated heart rate variability (HRV. As such, HRV may be useful in assessing clinical status in DHF patients, but is prone to erroneous results and conclusions due to the influence of the average HR during the time period of HRV assessment (defined as the ’prevailing’ HR. We tested the hypothesis that alterations in HRV calculated with linear frequency analysis would be minimal when mathematically corrected for prevailing HR following dengue viral infection. Methods: Male (N=16 and female (N= 11 patients between the ages of 6 months and 15 years of age (10 ± 6 SD years were tracked through the progression of the dengue viral infection with treatment following the abatement of a fever (defervescence. Electrocardiographic recordings were collected and analyzed for HRV. Results: High frequency (HF, low frequency (LF, and LF/HF ratio were unaffected by correction for prevailing HR. Conclusion: HRV corrected for changes in HR did not alter the interpretations of our data. Therefore, we conclude that cardiac parasympathetic activity (HF frequency is responsible for the majority of the HR reduction following defervescence in patients with dengue viral infection.

ROBERTCARTER III

2014-02-01

147

Robust efficient estimation of heart rate pulse from video  

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We describe a simple but robust algorithm for estimating the heart rate pulse from video sequences containing human skin in real time. Based on a model of light interaction with human skin, we define the change of blood concentration due to arterial pulsation as a pixel quotient in log space, and successfully use the derived signal for computing the pulse heart rate. Various experiments with different cameras, different illumination condition, and different skin locations were conducted to demonstrate the effectiveness and robustness of the proposed algorithm. Examples computed with normal illumination show the algorithm is comparable with pulse oximeter devices both in accuracy and sensitivity. PMID:24761294

Xu, Shuchang; Sun, Lingyun; Rohde, Gustavo Kunde

2014-01-01

148

Heart rate changes during partial seizures: A study amongst Singaporean patients  

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Full Text Available Abstract Introduction Studies in Europe and America showed that tachycardia, less often bradycardia, frequently accompanied partial seizures in Caucasian patients. We determine frequency, magnitude and type of ictal heart rate changes during partial seizures in non-Caucasian patients in Singapore. Methods Partial seizures recorded during routine EEGs performed in a tertiary hospital between 1995 and 1999 were retrospectively reviewed. All routine EEGs had simultaneous ECG recording. Heart rate before and during seizures was determined and correlated with epileptogenic focus. Differences in heart rate before and during seizures were grouped into 4 types: (1 >10% decrease; (2 -10 to +20% change; (3 20–50% increase; (3 >50% increase. Results Of the total of 37 partial seizures, 18 were left hemisphere (LH, 13 were right hemisphere (RH and 6 were bilateral (BL in onset. 51% of all seizures showed no significant change in heart rate (type 2, 22% had moderate sinus tachycardia (type 3, 11% showed severe sinus tachycardia (type 4, while 16% had sinus bradycardia (type 1. Asystole was recorded in one seizure. Apart from having more tachycardia in bilateral onset seizures, there was no correlation between side of ictal discharge and heart rate response. Compared to Caucasian patients, sinus tachycardia was considerably less frequent. Frequency of bradycardia was similar to those recorded in the literature. Conclusions Significant heart rate changes during partial seizures were seen in half of Singaporean patients. Although sinus tachycardia was the most common heart rate change, the frequency was considerably lower compared to Caucasian patients. This might be due to methodological and ethnic differences. Rates of bradycardia are similar to those recorded in the literature.

Lim Shih-Hui

2001-09-01

149

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 fluctuat rate below 65 bpm and heart rate fluctuation less than 20 bpm in order to reduce the radiation exposure

150

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

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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

151

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

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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. PMID:24968229

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

152

Effects of Exercise Training on Heart Rate Variability in Chagas Heart Disease  

Science.gov (United States)

Background: Heart rate variability (HRV) is a marker of autonomic dysfunction severity. The effects of physical training on HRV indexes in Chagas heart disease (CHD) are not well established. Objective: To evaluate the changes in HRV indexes in response to physical training in CHD. Methods: Patients with CHD and left ventricular (LV) dysfunction, physically inactive, were randomized either to the intervention (IG, N = 18) or control group (CG, N = 19). The IG participated in a 12-week exercise program consisting of 3 sessions/week. Results: Mean age was 49.5 ± 8 years, 59% males, mean LVEF was 36.3 ± 7.8%. Baseline HRV indexes were similar between groups. From baseline to follow-up, total power (TP): 1653 (IQ 625 - 3418) to 2794 (1617 - 4452) ms, p = 0.02) and very low frequency power: 586 (290 - 1565) to 815 (610 - 1425) ms, p = 0.047) increased in the IG, but not in the CG. The delta (post - pre) HRV indexes were similar: SDNN 11.5 ± 30.0 vs. 3.7 ± 25.1 ms. p = 0.10; rMSSD 2 (6 - 17) vs. 1 (21 - 9) ms. p = 0.43; TP 943 (731 - 3130) vs. 1780 (921 - 2743) Hz. p = 0.46; low frequency power (LFP) 1.0 (150 - 197) vs. 60 (111 - 146) Hz. p = 0.85; except for high frequency power, which tended to increase in the IG: 42 (133 - 92) vs. 79 (61 - 328) Hz. p = 0.08). Conclusion: In the studied population, the variation of HRV indexes was similar between the active and inactive groups. Clinical improvement with physical activity seems to be independent from autonomic dysfunction markers in CHD. PMID:25098373

Nascimento, Bruno Ramos; Lima, Marcia Maria Oliveira; Nunes, Maria do Carmo Pereira; de Alencar, Maria Clara Noman; Costa, Henrique Silveira; Pinto Filho, Marcelo Martins; Cota, Vitor Emanuel Serafim; Rocha, Manoel Otavio da Costa; Ribeiro, Antonio Luiz Pinho

2014-01-01

153

Modeling baroreflex regulation of heart rate during orthostatic stress  

DEFF Research Database (Denmark)

During orthostatic stress, arterial and cardiopulmonary baroreflexes play a key role in maintaining arterial pressure by regulating heart rate. This study, presents a mathematical model that can predict the dynamics of heart rate regulation in response to postural change from sitting to standing. The model uses blood pressure measured in the finger as an input to model heart rate dynamics in response to changes in baroreceptor nerve firing rate, sympathetic and parasympathetic responses, vestibulo-sympathetic reflex, and concentrations of norepinephrine and acetylcholine. We formulate an inverse least squares problem for parameter estimation and successfully demonstrate that our mathematical model can accurately predict heart rate dynamics observed in data obtained from healthy young, healthy elderly, and hypertensive elderly subjects. One of our key findings indicates that to successfully validate our model against clinical data it is necessary to include the vestibulo-sympathetic reflex. Furthermore our model reveals that the transfer between the nerve firing and blood pressure is non-linear and follows a hysteresis curve. In healthy young people, the hysteresis loop is wide, while in healthy and hypertensive elderly people the hysteresis loop shifts to higher blood pressure values and its area is diminished. Finally, for hypertensive elderly people the hysteresis loop is generally not closed indicating that during postural change from sitting to standing, the blood pressure resettles at a different steady state value.

Olufsen, Mette; Tran, Hien T.

2006-01-01

154

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

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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

155

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

In order to assess the relative influence of age, resting heart rate (HR) and sedentary life style, heart rate variability (HRV) was studied in two different groups. The young group (YG) consisted of 9 sedentary subjects aged 15 to 20 years (YG-S) and of 9 nonsedentary volunteers (YG-NS) also aged 15 to 20. The elderly sedentary group (ESG) consisted of 16 sedentary subjects aged 39 to 82 years. HRV was assessed using a short-term procedure (5 min). R-R variability was calculated in the time-...

2001-01-01

156

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

157

Scaling characteristics of heart rate time series before the onset of ventricular tachycardia.  

Science.gov (United States)

Ventricular tachycardia (VT) provokes sudden cardiac death (SCD), which is a major cause of mortality in developed countries. Implantable cardioverter-defibrillators (ICDs) are an efficient therapy for SCD prevention. In this study we analyze heart rate variability (HRV) in data stored by ICDs. In 29 patients exhibiting VT episodes, the last 1000 normal beat-to-beat intervals are analyzed and compared to an individually acquired control time series (CON). HRV analysis is performed with standard parameters of time and frequency domain as suggested by the HRV Task Force. For scaling analyses of heart rate time series, the fractal dimension is analysed, applying Higuchi's algorithm (HFD). Furthermore, detrended fluctuation analysis (DFA) is performed. None of the standard HRV parameters shows significant differences between CON and VT. Before the onset of VT, the scaling characteristics by means of HFD and DFA are significantly changed. In conclusion, scaling analysis reveals changes in autonomic heart rate modulation preceding VT. PMID:17171301

Baumert, Mathias; Wessel, Niels; Schirdewan, Alexander; Voss, Andreas; Abbott, Derek

2007-02-01

158

Heart Rate Variability Interventions for Concussion and Rehabilitation  

Directory of Open Access Journals (Sweden)

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

RobertLakeConder

2014-08-01

159

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

160

Simplifying cardiovascular risk estimation using resting heart rate.  

LENUS (Irish Health Repository)

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

Cooney, Marie Therese

2010-09-01

 
 
 
 
161

A PC-aided optical foetal heart rate detection system.  

Science.gov (United States)

Safe monitoring of foetal heart rate is a valuable tool for the healthy evolution and wellbeing of both foetus and mother. This paper presents a non-invasive optical technique that allows for foetal heart rate detection using a photovoltaic infrared (IR) detector placed on the mother's abdomen. The system presented here consists of a photoplethysmography (PPG) circuit, abdomen circuit and a personal computer equipped with MATLAB. A near IR beam having a wavelength of 880?nm is transmitted through the mother's abdomen and foetal tissue. The received abdominal signal that conveys information pertaining to the mother and foetal heart rate is sensed by a low noise photodetector. The PC receives the signal through the National Instrumentation Data Acquisition Card (NIDAQ). After synchronous detection of the abdominal and finger PPG signals, the designed MATLAB-based software saves, analyses and extracts information related to the foetal heart rate. Extraction is carried out using recursive least squares adaptive filtration. Measurements on eight pregnant women with gestational periods ranging from 35-39 weeks were performed using the proposed system and CTG. Results show a correlation coefficient of 0.978 and a correlation confidence interval between 88-99.6%. The t test results in a p value of 0.034, which is less than 0.05. Low power, low cost, high signal-to-noise ratio, reduction of ambient light effect and ease of use are the main characteristics of the proposed system. PMID:24195701

Oweis, Rami J; As'ad, Hala; Aldarawsheh, Amany; Al-Khdeirat, Rawan; Lwissy, Kaldoun

2014-01-01

162

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

163

Heart Rate and Stress in a College Setting  

Science.gov (United States)

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

Elwess, Nancy L.; Vogt, F. Daniel

2005-01-01

164

Exploring the Relationship between Fetal Heart Rate and Cognition  

Science.gov (United States)

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

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

2010-01-01

165

An improved method of measuring heart rate using a webcam  

Science.gov (United States)

Measuring heart rate traditionally requires special equipment and physical contact with the subject. Reliable non-contact and low-cost measurements are highly desirable for convenient and comfortable physiological self-assessment. Previous work has shown that consumer-grade cameras can provide useful signals for remote heart rate measurements. In this paper a simple and robust method of measuring the heart rate using low-cost webcam is proposed. Blood volume pulse is extracted by proper Region of Interest (ROI) and color channel selection from image sequences of human faces without complex computation. Heart rate is subsequently quantified by spectrum analysis. The method is successfully applied under natural lighting conditions. Results of experiments show that it takes less time, is much simpler, and has similar accuracy to the previously published and widely used method of Independent Component Analysis (ICA). Benefitting from non-contact, convenience, and low-costs, it provides great promise for popularization of home healthcare and can further be applied to biomedical research.

Liu, Yi; Ouyang, Jianfei; Yan, Yonggang

2014-09-01

166

On direct sequential analysis of heart rate variability signals  

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Full Text Available Heart rate variability analysis represents one of the most promising and the most commonly used quantitative measures of the cardiovascular autonomic regulatory system. The analysis includes traditional statistical analytical tools and a number of new methods based on nonlinear system theory, recently developed to give better insight into complex HR. This paper introduces a direct sequential analysis.

Baji? Dragana

2005-01-01

167

Neural network for estimating energy expenditure in paraplegics from heart rate.  

Science.gov (United States)

The aim of the present study is to obtain models for estimating energy expenditure based on the heart rates of people with spinal cord injury without requiring individual calibration. A cohort of 20 persons with spinal cord injury performed a routine of 10 activities while their breath-by-breath oxygen consumption and heart rates were monitored. The minute-by-minute oxygen consumption collected from minute 4 to minute 7 was used as the dependent variable. A total of 7 features extracted from the heart rate signals were used as independent variables. 2 mathematical models were used to estimate the oxygen consumption using the heart rate: a multiple linear model and artificial neural networks. We determined that the artificial neural network model provided a better estimation (r=0.88, MSE=4.4?ml?·?kg(-1)?·?min(-1)) than the multiple linear model (r=0.78; MSE=7.63?ml?·?kg(-1)?·?min(-1)).The goodness of fit with the artificial neural network was similar to previous reported linear models involving individual calibration. In conclusion, we have validated the use of the heart rate to estimate oxygen consumption in paraplegic persons without individual calibration and, under this constraint, we have shown that the artificial neural network is the mathematical tool that provides the better estimation. PMID:24886923

García-Massó, X; Serra-Añó, P; García-Raffi, L; Sánchez-Pérez, E; Giner-Pascual, M; González, L-M

2014-11-01

168

Prognostic significance of heart rate in hospitalized patients presenting with myocardial infarction  

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Full Text Available AIM: To investigate the prognostic significance of resting heart rate in patients with acute coronary syndrome (ACS, independent of other known factors. METHODS: Patients 40 years of age or older who had been admitted with acute coronary syndrome (ACS to one of the 94 hospitals participating in the Prevalence of Peripheral Arterial Disease in Patients with Acute Coronary Syndrome (PAMISCA study were included. Patients were divided into two groups based on their resting heart rate (HR ? or < 70 bpm. Complications were recording during a follow-up period of 1 year. RESULTS: There were 1054 ACS patients analyzed (43.5% with ST segment elevation and 56.5% without elevation. Mean age was 66.6 ± 11.7 years, 70.6% were male and 29.4% of subjects were female. During follow-up, more patients in the HR ? 70 bpm group were hospitalized for heart failure and they also had a higher mortality rate. In the multivariate analysis, a heart rate of ? 70 bpm was independently related to overall mortality during the follow-up period (hazard ratio 2.5; 95% confidence interval, 1.26-4.97, P = 0.009. CONCLUSION: A resting heart rate ? 70 bpm in patients who survive an ACS is an indicator of a high risk of suffering cardiovascular events during follow-up.

Lorenzo Fácila

2012-01-01

169

Heart rate variability and target organ damage in hypertensive patients  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 in...

Melillo Paolo; Izzo Raffaele; Luca De Nicola; Pecchia Leandro

2012-01-01

170

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

171

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

172

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Davey, P.

1999-01-01

173

Frequency dependent effect of selective biphasic left vagus nerve stimulation on heart rate and arterial pressure  

Directory of Open Access Journals (Sweden)

Full Text Available Activation of the parasympathetic pathway leads to negative chronotropic, dromotropic, and inotropic changes of heart function. The ability to selectively stimulate certain superficial compartments of peripheral nerves has been demonstrated previously. The aim of the present study was to find a clinically acceptable selective biphasic vagus nerve stimulation technique, which could allow gradual regulation of heart rate and systemic arterial pressure. In two patients, the left vagus nerve was stimulated with a combination of quasi-trapezoidal cathodic and rectangular anodic current pulses with different stimulation frequencies (10Hz, 20Hz, 30Hz and increasing current. The heart rate and systemic arterial pressure decreased with increasing current at all different stimulation frequencies (p<0.05. The heart rate and arterial pressure response was more gradual with 10Hz compared to 20Hz/30Hz vagus nerve stimulation (p<0.05. In conclusion, selective vagus nerve stimulation, with a combination of quasi-trapezoidal cathodic and rectangular anodic current pulses at 10Hz, offers gradual heart rate and systolic arterial pressure control.

MATEJ PODBREGAR

2012-10-01

174

Identifying Genetic Variants for Heart Rate Variability in the Acetylcholine Pathway  

Science.gov (United States)

Heart rate variability is an important risk factor for cardiovascular disease and all-cause mortality. The acetylcholine pathway plays a key role in explaining heart rate variability in humans. We assessed whether 443 genotyped and imputed common genetic variants in eight key genes (CHAT, SLC18A3, SLC5A7, CHRNB4, CHRNA3, CHRNA, CHRM2 and ACHE) of the acetylcholine pathway were associated with variation in an established measure of heart rate variability reflecting parasympathetic control of the heart rhythm, the root mean square of successive differences (RMSSD) of normal RR intervals. The association was studied in a two stage design in individuals of European descent. First, analyses were performed in a discovery sample of four cohorts (n?=?3429, discovery stage). Second, findings were replicated in three independent cohorts (n?=?3311, replication stage), and finally the two stages were combined in a meta-analysis (n?=?6740). RMSSD data were obtained under resting conditions. After correction for multiple testing, none of the SNPs showed an association with RMSSD. In conclusion, no common genetic variants for heart rate variability were identified in the largest and most comprehensive candidate gene study on the acetylcholine pathway to date. Future gene finding efforts for RMSSD may want to focus on hypothesis free approaches such as the genome-wide association study. PMID:25384021

Riese, Harriette; Munoz, Loretto M.; Hartman, Catharina A.; Ding, Xiuhua; Su, Shaoyong; Oldehinkel, Albertine J.; van Roon, Arie M.; van der Most, Peter J.; Lefrandt, Joop; Gansevoort, Ron T.; van der Harst, Pim; Verweij, Niek; Licht, Carmilla M. M.; Boomsma, Dorret I.; Hottenga, Jouke-Jan; Willemsen, Gonneke; Penninx, Brenda W. J. H.; Nolte, Ilja M.; de Geus, Eco J. C.; Wang, Xiaoling; Snieder, Harold

2014-01-01

175

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

176

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

Energy Technology Data Exchange (ETDEWEB)

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

Laspas, Fotios; Roussakis, Arkadios; Kritikos, Nikolaos; Efthimiadou, Roxani; Kehagias, Dimitrios; Andreou, John (CT and MRI Dept., Hygeia Hospital, Athens (Greece)), e-mail: fotisdimi@yahoo.gr; Tsantioti, Dimitra (Statistician, Hygeia Hospital, Athens (Greece))

2011-04-15

177

The cardiovascular helix: a three-dimensional view of blood pressure and heart rate over time.  

Science.gov (United States)

BACKGROUND: The baroreflex system plays an important role in the fast regulation of blood pressure. Conventional determination of baroreflex sensitivity either by pharmacological or by physical methods has proven cumbersome. Alternative approaches are based on continuously recording data of systolic arterial blood pressure (SAP) and heart rate, with evaluation by regression assessment or spectral analysis. Data selection for both methods results in various conflicts. We therefore developed a non-invasive method to evaluate baroreceptor functioning on the basis of a visual representation that would be independent of the restrictions related to regression and spectral analysis.METHODS: By plotting SAP and heart rate (measured by using a Finapres device) of 33 young men against time in a three-dimensional space, a helical structure could be visualized for subjects at rest as well as under stress. The shape of the helix was determined by the phase lag between SAP and heart rate and by the amplitude ratio. On the basis of this helix a model using two sinusoidal representations of SAP and heart rate parameterized the interaction between blood pressure and heart rate. The transfer function analysis was studied by means of a curve-fitting method similar to the Monte Carlo method. RESULTS: We found baroreceptor gain mode to be 9 ms/mmHg for subjects under stress and 11 ms/mmHg for subjects at rest. The values of phase lag between SAP and heart rate tended to gather around approximately 90 degrees. CONCLUSION: This method can be applied using even small sets of data over random periods of time. PMID:10234119

Kollenbaum; Schnoor; Meyer; Meyer

1997-10-01

178

Fetal heart rate pattern and umbilical cord nucleated RBC count  

Directory of Open Access Journals (Sweden)

Full Text Available "nBackground: Previous studies have suggested the presence of a relationship between the increase of NRBC and the duration and intensity of asphyxia. The purpose of this study was to evaluate the relationship of fetal heart rate pattern and the number of NRBC's in umbilical cord blood sample at birth. "nMethods: We enrolled 322 pregnant women with healthy, term fetuses who referred to Mirza Kouchak Khan Hospital for pregnancy termination in 2005 in a case-control study. All patients underwent continuous FHR monitoring and based on their FHR pattern, they were divided into two groups with normal FHR pattern and at least one abnormality in FHR pattern (including absence of beat to beat variability; absence of proper acceleration; and early, late, variable and prolonged deceleration. Samples of umbilical cord blood were evaluated for NRBC count and pH immediately after birth. The variables were compared in these two groups. "nResults: The mean NRBC count was significantly higher in patients with any kind of deceleration (late, variable, early or prolonged in comparison with controls (respectively 11.88±4.406, 8.32±4.64, 10.58±5.366, and 4.11±4.913 vs. 0.93±1.790 in controls. Furthermore the mean NRBC count was significantly higher in patients with absence of acceleration or beat to beat variability (10.73±5.07 and 13.73±3.58 vs. 1.47±2.50. There was a negative correlation between 5th minute Apgar score and umbilical cord blood sample with mean NRBC count of umbilical cord blood sample. "nConclusion: Any abnormality in FHR pattern is associated with a significant increase in mean NRBC count of umbilical cord blood sample. There is also a significant relationship between the 5th minute Apgar score and umbilical cord blood sample pH, and mean NRBC count in umbilical cord blood sample.

Niroumanesh Sh

2009-04-01

179

Heart Rate Variability: Why Chaos can be healthy  

Directory of Open Access Journals (Sweden)

Full Text Available Body autonomic interactions, mediated by sympathetic-parasympathetic balance, have been widely associated with stress and internal homeostasis. The acquisition of data, otherwise hidden in the signal from RR interval duration in heart rate, has given scientists access to the quantification of autonomic balance in humans, as long as the appropriate mathematical analyses are performed. With this information it is possible to know and understand the chaotic behavior of RR signals; this behavior shows the existence of heart rate variability (HRV. Variability is lost in some conditions associated with the presence of pathologies. In addition, with exercise being a stress agent, HRV analysis has been used as a tool to study training load assimilation and overtraining syndrome.

Jorge Cancino

2011-12-01

180

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.

Steve G. Fancy

1986-06-01

 
 
 
 
181

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

182

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

183

Rate-Dependent Action Potential Alternans in Human Heart Failure Implicate Abnormal Intracellular Calcium Handling  

Science.gov (United States)

Background Alternans in action potential voltage (APV-ALT) at heart rates 400% for CL500% at CL<350ms. For all other model alterations and for control patients, APV-ALT occurred only at CL<500ms. Conclusions APV-ALT shows differing rate-dependence in HF versus control patients, arising at slower rates in HF and predicted by models with abnormal calcium handling. Future studies should investigate whether APV-ALT at slow rates identifies patients with deranged calcium handing, including HF patients prior to decompensation or at risk for arrhythmias. PMID:20382266

Bayer, Jason D.; Narayan, Sanjiv M.; Lalani, Gautam G.; Trayanova, Natalia A.

2010-01-01

184

Heart Rate Variability in Patients with Rheumatoid Arthritis  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 Universit...

Kawser Jahan, Noorzahan Begum

2012-01-01

185

Scaling and Ordering of Neonatal Heart Rate Variability  

Science.gov (United States)

By analyzing cardiac beat-to-beat intervals and interbeat increments, we find that-unlike adults-the difference in the pattern of interbeat increments in healthy and sick newborn infants is more due to a change in the amplitude and much less to a change in the ordering of the interbeat increments. This suggests that very low-frequency elements of neonatal and adult heart rate variability rise from fundamentally different mechanisms.

Aghili, Ali A.; Rizwan-Uddin, Rizwan-Uddin; Griffin, M. Pamela; Moorman, J. Randall

1995-02-01

186

Elevated resting heart rate is associated with the metabolic syndrome  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Background Increased resting heart rate (RHR) may be associated with increased cardiovascular morbidity. Our aim was to explore the possibility that increased RHR is associated with the prevalence of the metabolic syndrome (MetS) in a sample of apparently healthy individuals and those with cardiovascular risk factors. Methods We performed a cross-sectional analysis in a large sample of apparently healthy individuals who attended a general health screeni...

Saar Nili; Cohen Michael; Berliner Shlomo; Steinvil Arie; Rogowski Ori; Kliuk Ben-Bassat Orit; Shapira Itzhak

2009-01-01

187

Development of a heart rate variability analysis tool  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Heart Rate Variability (HRV) concerns the analysis of the phenomenon underlying the variability between consecutive heartbeats. During the last three decades, significant effort has been made to understand its physiological basis and implications in different pathologies. Such studies have revealed, among other aspects, that HRV its a mirror of the control actions exerted by the Autonomic Nervous System (ANS) in the Sinoatrial (SA) node. Since the SA node is responsible for set...

Medeiros, Jose? Miguel

2010-01-01

188

Heart rate control in hypertensive patients treated by captopril.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

1 The effect of captopril on autonomic reflex functions has been investigated in fifteen patients with essential hypertension by examining their responses to tests of baroreceptor function (Valsalva's manoeuvre and upright posture), sympathetic nervous system reactivity (cold pressor and mental stress tests) and parasympathetic reactivity (diving test) before and after 3 weeks' treatment with captopril. 2 Captopril significantly reduced arterial blood pressure and resting heart rate but did n...

Sturani, A.; Chiarini, C.; Degliesposti, E.; Santoro, A.; Zuccala?, A.; Zucchelli, P.

1982-01-01

189

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

190

Design and development of a heart rate variability analyzer.  

Science.gov (United States)

Heart rate variability (HRV), analysis gives an insight into the state of the autonomic nervous system which modulates the cardiac activity. Here a digital signal controller based handy device is developed which acquires the beat to beat time interval, processes it using techniques based on non-linear dynamics, fractal time series analysis, and information theory. The technique employed, that can give reliable results by assessing heart beat signals fetched for a duration of a few minutes, is a huge advantage over the already existing methodologies of assessing cardiac health, those being dependant on the tedious task of acquiring Electro Cardio Gram(ECG) signals, which in turn requires the subject to lie down at a stretch for a couple of hours. The sensor used, relies on the technique of Photoplethysmography, rendering the whole approach as noninvasive. The device designed, calculates parameters like, Largest Lyapunov Exponent, Fractal dimension, Correlation Dimension, Approximate Entropy and ?-slope of Poincare plots, which based on the range in which they fall, the cardiac health condition of the subject can be assessed to even the extend of predicting upcoming disorders. The design of heart beat sensor, the technique used in the acquisition of heart beat data, the relevant algorithm developed for the analysis purpose, are presented here. PMID:21057888

Mohan, Aparna; James, Frana; Fazil, Sajeer; Joseph, Paul K

2012-06-01

191

A COMPARATIVE STUDY OF HEART RATE VARIABILITY IN DIABETIC SUBJECTS AND NORMAL SUBJECTS  

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Full Text Available Aim: The main objective of this study is to enlighten medical faculty and diabetic patients about neurological and cardiovascular complications in Diabetes and to compare heart rate variability in normal individuals and diabetic patients. Materials and method :This research study was case-control study using Niviqure data acquisition system to record 5-minutes E.C.G. in 400 individuals who consisted of the cases group comprised of 200 diabetic patients and controls group consisted of 200 healthy individuals.5-minutes E.C.G. data gathered was subjected to frequency domain analysis of Heart Rate Variability and from which various parameter depicting parasympathetic activity and sympathetic activity were analyzed. HbA1c levels were estimated by high performance liquid chromatography. Statistical analysis was done using MS office excel 2007 software. Results: In the present study it was observed that parameters of heart rate variability are reduced (power of High Frequency-H.F., power of Low Frequency-L.F., total power-T.P. and L.F. /H.F. ratio and parameters of heart rate variability depicting parasympathetic modulation of heart (H.F. are more reduced when compared to parameters of heart rate variability depicting sympathetic modulation (L.F. in diabetics compared to normal individuals. It was also found that there is a negative correlation between HbA1c values of subjects and parameters of HRV. Conclusion: These results may be attributed to early parasympathetic damage due to axonal degeneration of longer vagal fibers .This axonal degeneration is mostly caused due to chronically elevated levels of blood glucose.

Lakshmi A.N.R.

2012-09-01

192

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

193

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

Sarkar, A.; Barat, P.

2006-01-01

194

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

195

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

196

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.

197

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)

198

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

199

Heart rate variability and baroreceptor responsiveness to evaluate autonomic cardiovascular adaptations to exercise  

Directory of Open Access Journals (Sweden)

Full Text Available Exercise physiologists routinely evaluate adaptations to exercise such as aerobic capacity, muscular strength and flexibility, and body composition, but often overlook the effects of exercise training on autonomic regulation of cardiovascular function. A preponderance of cross-sectional studies report significant resting sinus bradycardia and high heart rate variability in active subjects, and suggest that exercise training induces adaptations in autonomic cardiovascular control. Alternatively, data from cross-sectional studies leave open the possibility that individuals with a genetic predisposition for lower heart rates or greater heart rate variability are also endowed with greater aerobic capacity. Conflicting results from a limited number of exercise training studies fail to conclusively demonstrate a direct effect of exercise training on the autonomic nervous system. In this report I suggest that simple measures of heart rate variability during controlled frequency breathing, and arterial baroreceptor responsiveness to Valsalva's maneuver provide unique insights into autonomic regulation of cardiovascular function. I propose that systemic-wide integration of exercise training effects might be better characterized if exercise physiologists would perform tests of autonomic function in conjunction with standard exercise tests during routine laboratory evaluations.

WILLIAM H. COOKE

200

Mobilisation readiness state and the frequency structure of heart rate variability  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A number of studies showed association of mental status with heart rate variability. This work discovered a feature of frequency structure of heart rate variability that is associated with mental readiness. In three independent groups of 64, 39, and 19 volunteers by the factor analysis of heart rate periodograms, it has been discovered that there are at least two other heart rate oscillation phenomena apart from the well known low frequency oscillations and respiratory arrhy...

Mukhin, V.; Klimenko, V.

2010-01-01

 
 
 
 
201

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

Science.gov (United States)

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. PMID:23583979

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

202

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

DEFF Research Database (Denmark)

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 identifynew therapeutic targets.

den Hoed, Marcel; Eijgelsheim, Mark

2013-01-01

203

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

Science.gov (United States)

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

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

2010-01-01

204

Comparison of Traditional and Alternative Fitness Teaching Formats on Heart Rate Intensity and Perceived Enjoyment.  

Science.gov (United States)

Compared a traditional and an alternative (skill-fitness- music) fitness teaching format to determine whether there would be differences on Hong Kong middle school students' heart rate intensity and perceived enjoyment. Data from heart rate monitors and student surveys indicated that the two formats did not produce differences in heart rates.…

Ha, Amy Sau-ching; Heung-Sang Wong, Stephen

2002-01-01

205

[Dependence of the circadian organization of heart rate regulation by prolonged musical sensory influence].  

Science.gov (United States)

It's shown that prolonged acoustic sensory influence in the form of classic music may change neurovegetative control of heart rate, enhancing the parasympathetic influences on heart rate variability, especially in night. These alterations increase expression of diurnal rhythm of ergotropic and trophotropic systems activity and lead to normalization of circadian profile of heart rate. PMID:17461021

Kirillova, I A; Maliarenko, T N; Voronin, I M; Govsha, Iu A

2007-02-01

206

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

Science.gov (United States)

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

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

2008-01-01

207

The Relationship between Heart Rate Reserve and Oxygen Uptake Reserve in Children and Adolescents  

Science.gov (United States)

The purpose of the present study was to examine the relationship between oxygen uptake (VO[subscript 2]) and heart rate (HR) responses during rest and exercise in Chinese children and youth and to evaluate the relationships between maximal heart rate (%HRmax), heart rate reserve (%HRR), peak oxygen uptake (%VO[subscript 2]peak), and oxygen uptake…

Hui, Stanley Sai-chuen; Chan, Janus Wan-sze

2006-01-01

208

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

Science.gov (United States)

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

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

2008-01-01

209

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

210

Sweet Conclusion  

Science.gov (United States)

Jen Harrington is the owner and pastry chef of Sweet Conclusion, a bakery in Tampa, Florida. Most of Harrington's business comes from baking wedding cakes, but she has been attempting to attract customers to her retail bakery, where she sells cupcakes, pies, ice cream, and coffee. Nearly four years she opened Sweet Conclusion, the retail part of…

Shirley, Britt M.; Wooldridge, Barbara Ross; Camp, Kerri M.

2012-01-01

211

Omega-3 Polyunsaturated Fatty Acids and Heart Rate Variability  

DEFF Research Database (Denmark)

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 afteromega-3 PUFA supplementation. However, the results are not consistent and further research is needed.

Christensen, Jeppe Hagstrup

2011-01-01

212

Omega-3 Polyunsaturated Fatty Acids and Heart Rate Variability  

Directory of Open Access Journals (Sweden)

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

213

Heart rate and estimated energy expenditure during ballroom dancing.  

Science.gov (United States)

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

Blanksby, B A; Reidy, P W

1988-06-01

214

Simultaneous nonstress fetal heart rate testing in twin pregnancy.  

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Twenty-four sets of twins in the third trimester of pregnancy underwent 120 simultaneously recorded nonstress tests (NSTs). Synchronous patterns of fetal heart rate alterations occurred in 58% of the cases and were associated with single placentas and small weight differences between twins. Reactive NSTs were frequent (77%) and, when they occurred within 1 week of delivery, conferred a good prognosis, ie, no perinatal deaths and low morbidity. Nonreactive NSTs were associated with both fetal deaths and a perinatal morbidity of 28%. simultaneous NSTs for twins are technically feasible in the third trimester. They confer a reliable prognosis when reactive; nonreactive tests are less specific and require further investigation. PMID:7279339

Devoe, L D; Azor, H

1981-10-01

215

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

Science.gov (United States)

In recent years there has been substantial support for heart rate variability biofeedback (HRVB) as a treatment for a variety of disorders and for performance enhancement (Gevirtz, 2013). Since conditions as widely varied as asthma and depression seem to respond to this form of cardiorespiratory feedback training, the issue of possible mechanisms becomes more salient. The most supported possible mechanism is the strengthening of homeostasis in the baroreceptor (Vaschillo et al., 2002; Lehrer et al., 2003). Recently, the effect on the vagal afferent pathway to the frontal cortical areas has been proposed. In this article, we review these and other possible mechanisms that might explain the positive effects of HRVB. PMID:25101026

Lehrer, Paul M; Gevirtz, Richard

2014-01-01

216

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

Directory of Open Access Journals (Sweden)

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

PaulMLehrer

2014-07-01

217

Impact of caffeine on heart rate and blood pressure at rest and during exercise  

Directory of Open Access Journals (Sweden)

Full Text Available Introduction:Several studies have evaluated the impact of caffeine consumption on athletes performance from different aspects; however, the findings are varied. The aim of this research was to evaluate the impact of caffeine consumption on some of the cardiovascular factors including heart rate and blood pressure at rest, at the end of exercise, and during the 3rd and 5th minutes of recovery. Material and Methods:The subjects of this study included 20 female athletes, voluntarily participating in the study. Two separate tests with an interval of one week were conducted. The subjects received placebo for the first test and caffeine containing capsules (5 mg/kg for the second test. The patient heart rate and blood pressure were measured at rest, at the end of the exercise and during the 3rd and 5th minutes of recovery after submaximal test. Maximal oxygen consumption (VO2max was measured using Fax submaximal cardiorespiratory test. Paired t- test was used for data analysis. Results:Caffeine consumption had no significantly effect on VO2max, resting and end exercise heart rate, and blood pressure recorded at the end of the exercise. Caffeine consumption caused a significant increase in the heart rate during 3rd and 5th minutes of recovery, and in blood pressure at rest, and during the 3rd and the 5th minutes of recovery in the athletes. Conclusion:Due to the caffeine induced increase in blood pressure and heart rate, caffeine consumption (5 mg/kg before submaximal exercise is not recommended either for those who suffer hypertension or cardiac disease nor for those who do exercise for health or athletic purposes.

Azam Mousavi

2011-05-01

218

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. PMID:24066715

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

219

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

220

A Comparison of Verapamil and Digoxin for Heart Rate Control in Atrial Fibrillation  

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Full Text Available Purpose: Atrial fibrillation (AF is one of the most common types of sustained dysrhythmia and there are some disagreements about its treatment. The goals of AF treatment include the control of ventricular rate, the establishment of sinus rhythm and the prevention of thromboembolic events. In this study, the effect of verapamil was compared to digoxin on heart rate control in patients with AF. Methods:This descriptive study was conducted in an emergency department (ED in Iran. Sixty patients with a new onset AF and rapid ventricular response receiving digoxin or verapamil were included and observed. Results:Two thirty-patient groups receiving verapamil or digoxin were evaluated. The heart rate was significantly decreased in both groups (p = 0.002; however, the cardioversion was not noticed in both of them. The best rate control in verapamil and digoxin groups was observed after 5.9 mg (46.7% and 0.6 mg (36.7%, respectively. Conclusion: Administration of verapamil in comparison with digoxin has no difference to control the heart rate in AF patients. It should be taken into consideration that prospective randomized studies should be conducted to identify the efficacy and select the best of these two drugs to treat AF patients.

Mohammad Afzali Moghadam

2012-08-01

 
 
 
 
221

A Comparison of Verapamil and Digoxin for Heart Rate Control in Atrial Fibrillation  

Science.gov (United States)

Purpose: Atrial fibrillation (AF) is one of the most common types of sustained dysrhythmia and there are some disagreements about its treatment. The goals of AF treatment include the control of ventricular rate, the establishment of sinus rhythm and the prevention of thromboembolic events. In this study, the effect of verapamil was compared to digoxin on heart rate control in patients with AF. Methods: This descriptive study was conducted in an emergency department (ED) in Iran. Sixty patients with a new onset AF and rapid ventricular response receiving digoxin or verapamil were included and observed. Results: Two thirty-patient groups receiving verapamil or digoxin were evaluated. The heart rate was significantly decreased in both groups (p = 0.002); however, the cardioversion was not noticed in both of them. The best rate control in verapamil and digoxin groups was observed after 5.9 mg (46.7%) and 0.6 mg (36.7%), respectively. Conclusion: Administration of verapamil in comparison with digoxin has no difference to control the heart rate in AF patients. It should be taken into consideration that prospective randomized studies should be conducted to identify the efficacy and select the best of these two drugs to treat AF patients. PMID:24312794

Afzali Moghadam, Mohammad; Fadaie Dashti, Maryam; Shahsavarinia, Kavous; Mahmoodpoor, Ata; Jamali, Kazem

2012-01-01

222

Day-to-night time differences in the relationship between cardiorespiratory coordination and heart rate variability  

International Nuclear Information System (INIS)

Heart rate variability (HRV) and cardiorespiratory coordination, i.e. the temporal interplay between oscillations of heartbeat and respiration, reflect information related to the cardiovascular and autonomic nervous system. The purpose of this study was to investigate the relationship between spectral measures of HRV and measures of cardiorespiratory coordination. In 127 subjects from a normal population a 24 h Holter ECG was recorded. Average heart rate (HR) and the following HRV parameters were calculated: very low (VLF), low (LF) and high frequency (HF) oscillations and LF/HF. Cardiorespiratory coordination was quantified using average respiratory rate (RespR), the ratio of heart rate and respiratory rate (HRR), the phase coordination ratio (PCR) and the extent of cardiorespiratory coordination (PP). Pearson's correlation coefficient r was used to quantify the relationship between each pair of the variables across all subjects. HR and HRR correlated strongest during daytime (r = 0.89). LF/HF and PP showed a negative correlation to a reasonable degree (r = ?0.69). During nighttime sleep these correlations decreased whereas the correlation between HRR and RespR (r = ?0.47) as well as between HRR and PCR (r = 0.73) increased substantially. In conclusion, HRR and PCR deliver considerably different information compared to HRV measures whereas PP is partially linked reciprocally to LF/HF

223

Heart Rate and Blood Pressure: Any Possible Implications for Management of Hypertension?  

Science.gov (United States)

Hypertension is a common clinical problem and a major risk factor for cardiovascular disease and stroke. Elevated heart rate is associated with elevated blood pressure, increased risk for hypertension, and, among hypertensives, increased risk for cardiovascular disease. Despite these important relationships, heart rate is generally not a major consideration in choosing antihypertensive medications. In part, this is due to a lack of evidence supporting heart rate lowering as a therapeutic strategy in hypertension. Additionally, while there is a positive correlation between heart rate and peripheral blood pressure, there is an inverse relationship between heart rate and central blood pressure. The use of antihypertensive medications, specifically medications that affect heart rate, may not reliably reduce central blood pressure to a similar extent as observed peripherally. We review the relationship between heart rate and peripheral and central blood pressure, with a focus on the implications for chronotropic therapy in hypertension. PMID:22972532

Reule, Scott; Drawz, Paul E.

2012-01-01

224

HEART RATE AND MOTION ANALYSIS BY GPS IN BEACH SOCCER  

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Full Text Available Although beach soccer has become increasingly popular in recent years very little scientific research has been conducted into the sport. A pilot study was carried out with the aim of examining the physiological (heart rate and physical (motion analysis responses of beach soccer players during competitive matches. Ten players (age 25.5 ± 0.5 years; height 1.80 ± 0.08 m; weight 78.2 ± 5.6 kg. were studied over five beach soccer matches. The physiological demands were analysed by measuring heart rate (HR using telemetric devices, while the physical profile was evaluated by recording motion and speed by means of GPS devices. During competitive matches, players obtained a HRmean of 165.2 bpm (86.5% HRmax, with 59.3% of the time participating (TP corresponding to values above 90% of the HRmax. The distance covered per minute of participation was 97.7 m, with 9.5% of this distance corresponding to high-intensity running and 2.5% to sprint; the work:rest ratio was 1.4:1 and the maximum speed 21.7 km·h-1. These results showed that beach soccer is an intermittent physical activity of greater intensity than other team games. It requires a major contribution from the anaerobic system as emphasis is placed on players making quick bursts of high-intensity activity separated by brief rest periods

Julen Castellano

2010-03-01

225

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.

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

2003-08-01

226

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

227

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.

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

228

Conditioned tolerance to the heart rate effects of smoking.  

Science.gov (United States)

This study extended our findings that behavioral tolerance to nicotine in animals can be influenced by conditioning to cardiovascular tolerance in humans. Subjects smoked one-half a cigarette during each of five trials. In the ten-minute intersmoking interval the contexts that preceded smoking were varied. Smokers in the Changing group attended to a different five-minute segment of a Sherlock Holmes radio mystery before each trial, while those in the Repeated group listened to the same segment of the tape. Presmoking heart rates were stable across the groups from trials 1 to 5. As predicted, heart rate for subjects who smoked in the same context showed tolerance to smoking from trials 1 to 5 (84.5 to 78 bpm), while subjects who smoked in in the same context showed tolerance to 83.9 bpm). COa levels increased equally for both groups over the five trials. The results of this study suggest tolerance to smoking can be influenced by learning. PMID:1924497

Epstein, L H; Caggiula, A R; Perkins, K A; McKenzie, S J; Smith, J A

1991-05-01

229

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

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

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

2013-01-01

230

Drawing Conclusions  

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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

231

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

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Background: Little is known about the mechanisms explaining an increased perception of heart symptoms in congenital heart disease (ConHD). In the present study, it was suggested that a combination of high trait anxiety and disease history increases the perception of heart symptoms. Purpose: It was tested whether false heart cues will result in an increased perception of heart symptoms in patients with ConHD and anxiety. Method: Thirty-six patients with ConHD and 44 healthy controls pe...

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

2009-01-01

232

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

Science.gov (United States)

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. PMID:21789388

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

2011-01-01

233

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

234

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

Directory of Open Access Journals (Sweden)

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

235

Low-dose coronary-CT angiography using step and shoot at any heart rate: comparison of image quality at systole for high heart rate and diastole for low heart rate with a 128-slice dual-source machine.  

Science.gov (United States)

To compare image quality of coronary CT angiography in step-and-shoot mode at the diastolic phase at low heart rates (128-slice CT machine, at the diastolic phase in the 55 patients with heart rates 128-slice CT-angiography, step-and-shoot acquisition provides comparable mean image quality in systole, with less variability and fewer stair-step artifacts, compared to diastole. This method may be feasible at any heart rate in most patients in sinus rhythm, allowing low-dose prospective acquisition without beta-blocker premedication. PMID:22918571

Paul, Jean-François; Amato, Aude; Rohnean, Adela

2013-03-01

236

Atenolol Is Associated with Lower Day of Surgery Heart Rate as compared to Long and Short-acting Metoprolol  

Science.gov (United States)

Objectives We analyzed the association between outpatient beta-blocker type and day-of-surgery heart rate in ambulatory surgical patients. We further investigated whether differences in day of surgery heart rate between atenolol and metoprolol could be explained by once-daily versus twice-daily dosing regimens. Design Retrospective observational study. Setting VA Hospital Participants Ambulatory surgical patients on chronic atenolol or metoprolol. Interventions None. Measurements and Main Results Using a propensity-score matched cohort, we compared day of surgery heart rates of patients prescribed atenolol versus metoprolol. We then differentiated between once-daily and twice-daily metoprolol formulations and compared day of surgery heart rates within a general linear model. Day of surgery heart rates in patients prescribed atenolol vs. any metoprolol formulation were slower by a mean of 5.1 beats/min (66.6 vs. 71.7; 95% CI of difference 1.9 to 8.3, p=0.002), a difference that was not observed in preoperative primary care visits. The general linear model demonstrated that patients prescribed atenolol (typically QD dosing) had a mean day of surgery heart rate 5.6 beats/min lower compared to patients prescribed once-daily metoprolol succinate (68.9 vs. 74.5; 95% CI of difference: ?8.6 to ?2.6, pmetoprolol tartrate (68.9 vs. 72.7; 95% CI of difference: ?6.1 to ?1.6, pmetoprolol (95% CI of difference: ?1.0 to +4.6, p=0.22). Conclusions Atenolol is associated with lower day of surgery heart rate vs. metoprolol. The heart rate difference is specific to the day of surgery and is not explained by once-daily versus twice-daily dosing regimens. PMID:22889605

Schonberger, Robert B.; Brandt, Cynthia; Feinleib, Jessica; Dai, Feng; Burg, Matthew M.

2012-01-01

237

Long-term mortality risk in patients with an implantable cardioverter-defibrillator : Influence of heart rate and QRS duration  

DEFF Research Database (Denmark)

BACKGROUND: A paucity of studies has investigated the role of autonomic cardiac regulation as well as cardiac conduction in relation to prognosis in implantable cardioverter-defibrillator (ICD) patients. Therefore, we examined the association of heart rate and QRS duration with long-term mortality risk in first-time ICD patients, adjusting also for measures of emotional distress. METHODS: Resting heart rate and QRS duration were assessed prior to ICD implantation in 448 patients. Primary study endpoint was all-cause mortality (up to 6.0 year follow-up, median follow-up of 5.6 years (IQR: 1.9)). The impact of heart rate and QRS duration on time to all-cause mortality was separately assessed with Cox proportional hazard regression analysis, adjusting for clinical factors and symptoms of depression and anxiety. RESULTS: Mean (SD) heart rate was 68.0 ± 13.3 bpm and mean QRS duration was 130.9 ± 36.9 ms. Heart rate of ?80 bpm was associated with increased risk of mortality (HR=1.86; 95% CI=1.15-3.00; p=.011) in unadjusted analysis. In adjusted analyses, this relationship remained significant both with depression (HR=1.86, 95% CI=1.12-3.09; p=.017) and anxiety (HR=1.82, 95% CI=1.10-3.03; p=.021) and clinical measures as covariates. QRS duration of ?120 ms was associated with impaired prognosis in unadjusted analysis (HR=2.00, 95% CI=1.27-3.14; p=.003), but was reduced to non-significance in adjusted analysis when medical comorbidities were included (HR=1.15, 95% CI=0.70-1.89; p=.60). CONCLUSIONS: This study shows that increased heart rate is associated with impaired prognosis. Since heart rate is a relatively easy measurable parameter of autonomic functioning, heart rate should be included as a measure for risk stratification in daily clinical practice.

Hoogwegt, Madelein T; Theuns, Dominic A M J

2014-01-01

238

Antepartum fetal heart rate testing. II. Intrapartum fetal heart rate observation and newborn outcome following a positive contraction stress test.  

Science.gov (United States)

The positive contraction stress test (CST) has been looked upon as a predictor of fetal compromise. On this basis, some reports advise routine cesarean delivery on the assumption that the compromised fetus should not tolerate labor. Other authors advocate selective cesarean delivery, based on obstetrical factors such as the inducibility of the cervix and the practicality of fetal monitoring. Finally, an attempted trial of labor may be allowed on the basis of occurrence of fetal heart rate acceleration with fetal movement, or "reactivity." The occurrence of "false positive" tests is not infrequent (20 to 45 per cent). The definition of such is unclear and little quantitative information regarding intrapartum performance is available. In this series of 27 patients, a trial of labor was undertaken in 20. Vaginal delivery occurred in 11 (55 per cent) and cesarean section in nine (45 per cent). Fetal heart rate abnormalities thought to indicate "distress" occurred in five patients (25 per cent). The "positive" window or repetitive late deceleration as equivalent to the positive CST was seen in only three patients during labor. A trial of labor should be attempted in the face of a positive CST whenever obstetric factors are favorable and careful intrapartum monitoring can be performed. PMID:760533

Gauthier, R J; Evertson, L R; Paul, R H

1979-01-01

239

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english In order to assess the relative influence of age, resting heart rate (HR) and sedentary life style, heart rate variability (HRV) was studied in two different groups. The young group (YG) consisted of 9 sedentary subjects aged 15 to 20 years (YG-S) and of 9 nonsedentary volunteers (YG-NS) also aged 1 [...] 5 to 20. The elderly sedentary group (ESG) consisted of 16 sedentary subjects aged 39 to 82 years. HRV was assessed using a short-term procedure (5 min). R-R variability was calculated in the time-domain by means of the root mean square successive differences. Frequency-domain HRV was evaluated by power spectrum analysis considering high frequency and low frequency bands. In the YG the effort tolerance was ranked in a bicycle stress test. HR was similar for both groups while ESG showed a reduced HRV compared with YG. Within each group, HRV displayed a negative correlation with HR. Although YG-NS had better effort tolerance than YG-S, their HR and HRV were not significantly different. We conclude that HRV is reduced with increasing HR or age, regardless of life style. The results obtained in our short-term study agree with others of longer duration by showing that age and HR are the main determinants of HRV. Our results do not support the idea that changes in HRV are related to regular physical activity.

E.R., Migliaro; P., Contreras; S., Bech; A., Etxagibel; M., Castro; R., Ricca; K., Vicente.

2001-04-01

240

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

Directory of Open Access Journals (Sweden)

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

E.R. Migliaro

2001-04-01

 
 
 
 
241

Impact of heart rate and rhythm on radiation exposure in prospectively ECG triggered computed tomography  

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Purpose: To evaluate the influence of different heart rates and arrhythmias on scanner performance, image acquisition and applied radiation exposure in prospectively ECG triggered computed tomography (pCT). Materials and methods: An ECG simulator (EKG Phantom 320, Müller and Sebastiani Elektronik GmbH, Munich, Germany) was used to generate different heart rhythms and arrhythmias: sinus rhythm (SR) at 45, 60, 75, 90 and 120/min, supraventricular arrhythmias (e.g. sinus arrhythmia, atrial fibrillation) and ventricular arrhythmias (e.g. ventricular extrasystoles), pacemaker-ECGs, ST-changes and technical artifacts. The analysis of the image acquisition process was performed on a 64-row multidetector CT (Brilliance, Philips Medical Systems, Cleveland, USA). A prospectively triggered scan protocol as used for routine was applied (120 kV; 150 mA s; 0.4 s rotation and exposure time per scan; image acquisition predominantly in end-diastole at 75% R-R-interval, in arrythmias with a mean heart rate above 80/min in systole at 45% of the R-R-interval; FOV 25 cm). The mean dose length product (DLP) and its percentage increase from baseline (SR at 60/min) were determined. Result: Radiation exposure can increase significantly when the heart rhythm deviates from sinus rhythm. ECG-changes leading to a significant DLP increase (p < 0.05) were bifocal pacemaker (61%), pacemaker dysfunction (22%), SVES (20%), ventricular salvo (20%), and atrial fibrillation (14%). Significantly (p < 0.05) prolonged scan time (>8 s) could be observed in bifocal pacemaker (12.8 s), pacemaker dysfunction (10.7 s), atrial fibrillation (10.3 s) and sinus arrhythmia (9.3 s). Conclusion: In prospectively ECG triggered CT, heart rate and rhythm can provoke different types of scanner performance, which can significantly alter radiation exposure and scan time. These results might have an important implication for indication, informed consent and contrast agent injection protocols.

Luecke, Christian, E-mail: neep@gmx.de [University of Leipzig – Heart Center, Department of Diagnostic and Interventional Radiology, Strümpellstrasse 39, D-04289, Leipzig (Germany); Andres, Claudia; Foldyna, Borek [University of Leipzig – Heart Center, Department of Diagnostic and Interventional Radiology, Strümpellstrasse 39, D-04289, Leipzig (Germany); Nagel, Hans Dieter [Wissenschaft and Technik für die Radiologie, Buchhholz i.d.N (Germany); Hoffmann, Janine; Grothoff, Matthias; Nitzsche, Stefan; Gutberlet, Matthias; Lehmkuhl, Lukas [University of Leipzig – Heart Center, Department of Diagnostic and Interventional Radiology, Strümpellstrasse 39, D-04289, Leipzig (Germany)

2012-09-15

242

Impact of heart rate and rhythm on radiation exposure in prospectively ECG triggered computed tomography  

International Nuclear Information System (INIS)

Purpose: To evaluate the influence of different heart rates and arrhythmias on scanner performance, image acquisition and applied radiation exposure in prospectively ECG triggered computed tomography (pCT). Materials and methods: An ECG simulator (EKG Phantom 320, Müller and Sebastiani Elektronik GmbH, Munich, Germany) was used to generate different heart rhythms and arrhythmias: sinus rhythm (SR) at 45, 60, 75, 90 and 120/min, supraventricular arrhythmias (e.g. sinus arrhythmia, atrial fibrillation) and ventricular arrhythmias (e.g. ventricular extrasystoles), pacemaker-ECGs, ST-changes and technical artifacts. The analysis of the image acquisition process was performed on a 64-row multidetector CT (Brilliance, Philips Medical Systems, Cleveland, USA). A prospectively triggered scan protocol as used for routine was applied (120 kV; 150 mA s; 0.4 s rotation and exposure time per scan; image acquisition predominantly in end-diastole at 75% R-R-interval, in arrythmias with a mean heart rate above 80/min in systole at 45% of the R-R-interval; FOV 25 cm). The mean dose length product (DLP) and its percentage increase from baseline (SR at 60/min) were determined. Result: Radiation exposure can increase significantly when the heart rhythm deviates from sinus rhythm. ECG-changes leading to a significant DLP increase (p 8 s) could be observed in bifocal pacemaker (12.8 s), pacemaker dysfunction (10.7 s), atrial fibrillation (10.3 s) and sinus arrhythmia (9.3 s). Conclusion: In prospectively ECG triggered CT, heart rate and rhythm can provoke different types of scanner performance, which can significantly alter radiation exposure and scan time. These results might have an important implication for indication, informed consent and contrast agent injection protocols

243

Freqüência cardíaca e risco cardiovascular Heart rate and cardiovascular risk  

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Full Text Available A freqüência cardíaca (FC também está no centro das determinantes do tempo de vida dos seres vivos animais. Há quase uma constante quando se multiplica a FC pelo número de anos que, em média, vive um animal. O ser humano também tem correlações interessantes de tempo de vida e FC, com estudos epidemiológicos demonstrando maior sobrevivência naqueles com menor FC em repouso, hipertensos, com doença coronariana e na população geral. Neste artigo, revemos estes estudos epidemiológicos e a perspectiva de se, de fato reduzindo a FC, poderemos aumentar o tempo de vida, no caso dos pacientes com doença cardiovascular, de forma independente de outros fatores.Heart rate (HR is known to be one of the factors that in the animal world are related to mortality. When one multiplies resting HR by the average life time, for each animal species, the result is almost the same number, similar to a constant. Apparently, each class of living beings has its "maximal number of heart beats for a life". Herein considerations are made about the relationship between HR and survival in human beings. Some epidemiological studies are reviewed, especially those related to cardiovascular and coronary diseases correlated to deaths and discussions are directed towards the perspective of living longer by lowering the HR.

Luiz Antonio Machado César

2007-10-01

244

Freqüência cardíaca e risco cardiovascular / Heart rate and cardiovascular risk  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese A freqüência cardíaca (FC) também está no centro das determinantes do tempo de vida dos seres vivos animais. Há quase uma constante quando se multiplica a FC pelo número de anos que, em média, vive um animal. O ser humano também tem correlações interessantes de tempo de vida e FC, com estudos epidem [...] iológicos demonstrando maior sobrevivência naqueles com menor FC em repouso, hipertensos, com doença coronariana e na população geral. Neste artigo, revemos estes estudos epidemiológicos e a perspectiva de se, de fato reduzindo a FC, poderemos aumentar o tempo de vida, no caso dos pacientes com doença cardiovascular, de forma independente de outros fatores. Abstract in english Heart rate (HR) is known to be one of the factors that in the animal world are related to mortality. When one multiplies resting HR by the average life time, for each animal species, the result is almost the same number, similar to a constant. Apparently, each class of living beings has its "maximal [...] number of heart beats for a life". Herein considerations are made about the relationship between HR and survival in human beings. Some epidemiological studies are reviewed, especially those related to cardiovascular and coronary diseases correlated to deaths and discussions are directed towards the perspective of living longer by lowering the HR.

Luiz Antonio Machado, César.

245

Heart rate variability in risk stratification of cardiac patients.  

Science.gov (United States)

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

246

Heart Rate and Initial Presentation of Cardiovascular Diseases (Caliber)  

Science.gov (United States)

Abdominal Aortic Aneurysm; Coronary Heart Disease NOS; Unheralded Coronary Death; Intracerebral Haemorrhage; Heart Failure; Ischemic Stroke; Myocardial Infarction; Stroke; Peripheral Arterial Disease; Stable Angina Pectoris; Subarachnoid Haemorrhage; Transient Ischemic Attack; Unstable Angina; Cardiac Arrest, Sudden Cardiac Death

2013-09-17

247

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

Science.gov (United States)

In several human adults, certain solar activity rhythms may influence an about 7-day rhythm in heart rate. When no about-weekly feature was found in the rate of change in sunspot area, a measure of solar activity, the double amplitude of a circadian heart rate rhythm, approximated by the fit of a 7-day cosine curve, was lower, as was heart rate corresponds to about-weekly features in solar activity and/or relates to a sunspot cycle. PMID:11541945

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

1996-12-01

248

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

Directory of Open Access Journals (Sweden)

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

249

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

250

Spectral and Time Based Assessment of Meditative Heart Rate Signals  

Directory of Open Access Journals (Sweden)

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

251

Nonlinear modelling and control for heart rate response to exercise.  

Science.gov (United States)

In order to accurately regulate cardiovascular response to exercise for individual exerciser, this study proposes a modelling and control integrated approach based on ?-insensitive Support Vector Regression (SVR) and switching control strategy. Firstly, a control oriented modelling approach is proposed to depict nonlinear behaviours of cardiovascular response at both onset and offset of treadmill exercises by using support vector machine regression. Then, based on the established nonlinear time-variant model, a novel switching Model Predictive Control (MPC) algorithm has been proposed for the optimisation of exercise efforts. The designed controller can take into account both coefficient drifting and parameter jump by embedding the identified model coefficient into the optimiser and adopting switching strategy during the transfer between onset and offset of exercises. The effectiveness of the proposed modelling and control approach was shown from the regulation of dynamical heart rate response to exercise through simulation using MATLAB. PMID:23060418

Zhang, Y; Chen, W; Su, S W; Celler, B

2012-01-01

252

Correlated and uncorrelated heart rate fluctuations during relaxing visualization  

Science.gov (United States)

The heart rate variability (HRV) of healthy subjects practicing relaxing visualization is studied by use of three multiscale analysis techniques: the detrended fluctuation analysis (DFA), the entropy in natural time (ENT) and the average wavelet (AWC) coefficient. The scaling exponent of normal interbeat interval increments exhibits characteristics of the presence of long-range correlations. During relaxing visualization the HRV dynamics change in the sense that two new features emerge independent of each other: a respiration-induced periodicity that often dominates the HRV at short scales (interbeat intervals) and the decrease of the scaling exponent at longer scales (40-512 interbeat intervals). In certain cases, the scaling exponent during relaxing visualization indicates the breakdown of long-range correlations. These characteristics have been previously seen in the HRV dynamics during non-REM sleep.

Papasimakis, N.; Pallikari, F.

2010-05-01

253

Fetal heart rate monitoring based on independent component analysis.  

Science.gov (United States)

In this paper, an algorithm based on independent component analysis (ICA) for extracting the fetal heart rate (FHR) from maternal abdominal electrodes is presented. Three abdominal ECG channels are used to extract the FHR in three steps: first preprocessing procedures such as DC cancellation and low-pass filtering are applied to remove noise. Then the algorithm for multiple unknown source extraction (AMUSE) algorithm is fed to extract the sources from the observation signals include fetal ECG (FECG). Finally, FHR is extracted from FECG. The method is shown to be capable of completely revealing FECG R-peaks from observation leads even with a SNR=-200dB using semi-synthetic data. PMID:16446158

Najafabadi, Farshid Soheili; Zahedi, Edmond; Mohd Ali, Mohd Alauddin

2006-03-01

254

Heart rate variability and motion sickness during forklift simulator driving.  

Science.gov (United States)

The goal of the study was to determine the effect of a 1-h hour long forklift truck virtual simulator driving on the mechanism of autonomic heart rate (HR) regulation in operators. The participants were divided into 2 subgroups: subjects with no definite inclination to motion sickness (group A) and subjects with a definite inclination to motion sickness (group B). Holter monitoring of electrocardiogram (ECG) signal was carried out in all subjects during the virtual simulator driving. For 12 consecutive epochs of ECG signal, HR variability analysis was conducted in time and frequency domains. In subjects with a definite inclination to motion sickness after ~30 min of the driving, changes in parameter values were found indicating an increase in sympathetic and parasympathetic activity with parasympathetic dominance. PMID:22152505

Zu?ewicz, Krystyna; Saulewicz, Antoni; Konarska, Maria; Kaczorowski, Zbigniew

2011-01-01

255

Heart Rate Variability in Patients With Multiple Sclerosis  

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Full Text Available Objective: The aims of the present study were to compare heart rate variability (HRV parameters of patients with multiple sclerosis (MS and healthy controls and to investigate the correlations between HRV parameters and disease duration, subtype and severity.Methods: Thirty-two patients with MS [18 with relapsing-remitting MS (RRMS, 4 with primary progressive MS (PPMS and 10 with secondary progressive MS (SPMS] and 32 healthy, age-and sex-matched volunteers were included. HRV was evaluated by frequency-domain spectral analysis method; total power (TP, low frequency (LF power, high frequency (HF power, very low frequency (VLF power in absolute values and in normalized units (n.u. and the ratio of LF to HF was used.Results: The patients had lower TP, VLF, LF, HF and HF n.u. and higher LF n.u. and the ratio of LF to HF reflecting overall decreased HRV accompanied by sympathetic overactivity and parasympathetic hypoactivity. There was no association between EDSS score and HRV parameters; however, we found a positive correlation between disease duration and LF n.u. We did not find significant differences between the patients with RRMS and the patients with SPMS regarding cardiac autonomic activity. Although TP, LF power, HF power and VLF power of the patients with PPMS were lower than of the patients with RRMS and the patients with SPMS, no statistical analysis could be made for this group due to inadequate number of the patients in this group.Interpretation: Patients with MS have higher sympathetic and lower parasympathetic regulation activity of heart rate. Disease duration, rather than severity seems to be associated with increased sympathetic activity.

Fevzi BEKTA?LI

2009-09-01

256

Rapid heartbeat, but dry palms: reactions of heart rate and skin conductance levels to social rejection  

Science.gov (United States)

Background: Social rejection elicits negative mood, emotional distress, and neural activity in networks that are associated with physical pain. However, studies assessing physiological reactions to social rejection are rare and results of these studies were found to be ambiguous. Therefore, the present study aimed to examine and specify physiological effects of social rejection. Methods: Participants (n = 50) were assigned to either a social exclusion or inclusion condition of a virtual ball-tossing game (Cyberball). Immediate and delayed physiological [skin conductance level (SCL) and heart rate] reactions were recorded. In addition, subjects reported levels of affect, emotional states, and fundamental needs. Results: Subjects who were socially rejected showed increased heart rates. However, social rejection had no effect on subjects' SCLs. Both conditions showed heightened arousal on this measurement. Furthermore, psychological consequences of social rejection indicated the validity of the paradigm. Conclusions: Our results reveal that social rejection evokes an immediate physiological reaction. Accelerated heart rates indicate that behavior activation rather than inhibition is associated with socially threatening events. In addition, results revealed gender-specific response patterns suggesting that sample characteristics such as differences in gender may account for ambiguous findings of physiological reactions to social rejection.

Iffland, Benjamin; Sansen, Lisa M.; Catani, Claudia; Neuner, Frank

2014-01-01

257

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

258

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

259

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 noof 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

260

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 ˜15 bpm lower during exercise with the trained leg (P

Mortensen, Stefan Peter; Svendsen, Jesper H

2013-01-01

 
 
 
 
261

Individual differences in motor skills ability affect the self-regulation of heart rate.  

Science.gov (United States)

Twenty males who scored relatively high on the rotor-pursuit motor skills task (High performance group) were given seven 2-minute trials to increase heart rate and seven 2-minute trials to decrease heart rate, as were 20 males who scored relatively low on the rotor-pursuit task (Low performance group). Visual analogue feedback was not provided during the first and last acceleration and deceleration trials but was presented during all other trials. Both groups of subjects were able to decrease heart rate significantly with and without feedback. Subjects in the High performance group were able to increase heart rate significantly with feedback and could generalize this increase to a no-feedback trial following feedback trials. Subjects in the Low performance group could not increase heart rate with or without feedback. Changes in respiration rate paralleled those noted for heart rate, but changes in chin electromyographic activity generally did not parallel the heart rate results. The heart rate data are discussed in terms of motor skills theories of self-regulation of heart rate. PMID:6509113

McCanne, T R; Hathaway, K M

1984-06-01

262

Heart Rate Variability Predicts Cell Death and Inflammatory Responses to Global Cerebral Ischemia  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This study examines the relationship between autonomic functioning and neuropathology following cardiac arrest (CA) in mice. Within 24?h of CA, parasympathetic cardiac control, as indexed by high frequency (HF) heart rate variability, rapidly decreases. By day 7 after CA, HF heart rate variability was inversely correlated with neuronal damage and microglial activation in the hippocampus. Thus, by virtue of its sensitivity to central insult, HF heart rate variability may offer an inexpensive...

Norman, Greg J.; Karelina, Kate; Berntson, Gary G.; Morris, John S.; Zhang, Ning; Devries, A. Courtney

2012-01-01

263

Asymmetric properties of long-term and total heart rate variability  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We report on two new physiological phenomena: the long-term and total heart rate asymmetry, which describe a significantly larger contribution of heart rate accelerations to long-term and total heart rate variability. In addition to the existing pair of indices, \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} ...

Piskorski, Jaroslaw; Guzik, Przemyslaw

2011-01-01

264

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

265

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

266

Accuracy of pulse oximeters in estimating heart rate at rest and during exercise.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Pulse oximeters are being widely used for non-invasive, simultaneous assessment of haemoglobin oxygen saturation. They are reliable, accurate, relatively inexpensive and portable. Pulse oximeters are often used for estimating heart rate at rest and during exercise. However, at present the data available to validate their use as heart rate monitors are not sufficient. We evaluated the accuracy of two oximeters (Radiometer, ear and finger probe; Ohmeda 3700, ear probe) in monitoring heart rate ...

Iyriboz, Y.; Powers, S.; Morrow, J.; Ayers, D.; Landry, G.

1991-01-01

267

Prognostic value of heart rate variability in post-infarction patients  

Directory of Open Access Journals (Sweden)

Full Text Available Background/Aim. Depressed heart rate variability (HRV indicating autonomic disequilibrium and propensity to ventricular ectopy can be useful for risk stratification in patients following acute myocardial infarction (AIM. The aim of the study was to assess heart rate variability as a predictor of allcause mortality in post-infarction patients. Methods. We analyzed the 24-hour electrocardiographic (ECG recordings of 100 patients (80 males during hospitalization for AIM. The mean age of patients was 56.99 + 11.03 years. Time domain heart rate variability analysis was obtained from 8 to 13 days after index infarction by mean of a 24- hour ECG recording, and the calculated parameters were: standard deviation of all normal to normal RR intervals (SDNN, RRmax-RRmin (difference between the longest RR interval and the shortest RR interval, mean RR interval. We also analyzed ventricular premature complexes from the ECG data. The patients underwent clinical evaluation, laboratory tests and echocardiography. Results. Within a oneyear follow-up period 11 patients experienced death, 10 of them because of cardiac reason and one because of stroke. There were significantly lower values of SDNN (60.55 ± 12.84 ms vs 98.38 ± 28.21 ms, RRmax-RRmin (454.36 ± 111.00 ms vs 600.99 ± 168.72 ms and mean RR interval (695.82 ± 65.87 ms vs 840.07 ± 93.97 ms in deceased patients than in the survivors, respectively (p 10VPCs/h; p < 0.01. Multivariate Cox analysis showed that SDNN was a significant, independent predictor of all-cause mortality in postinfarction patients. The other independent predictors were clinical signs of heart failure - Killip class II and III and ventricular ectopic activity. Conclusion. Depressed HRV is an independent predictor of mortality in post-infarction patients and may provide useful additional prognostic information in non-invasive risk stratification of these patients.

Boškovi? Aneta

2014-01-01

268

RESTING HEART RATE AND THE RISK OF DEATH AND CARDIOVASCULAR COMPLICATIONS IN PATIENTS WITH TYPE 2 DIABETES MELLITUS  

Science.gov (United States)

Aim An association between resting heart rate and mortality has been described in the general population and in patients with cardiovascular disease. There are, however, few data exploring this relationship in patients with type 2 diabetes mellitus. The current study addresses this issue. Methods The relationship between baseline resting heart rate and all-cause mortality, cardiovascular death and major cardiovascular events (cardiovascular death, non-fatal myocardial infarction or non-fatal stroke) was examined in 11,140 patients who participated in the Action in Diabetes and Vascular Disease: Preterax and Diamicron Modified Release Controlled Evaluation (ADVANCE) study. Results A higher resting heart rate was associated with a significantly increased risk of all-cause mortality (fully adjusted hazard ratio [HR] 1.15 per 10 bpm, 95% confidence interval [CI] 1.08,1.21, p<0.001), cardiovascular death, and major cardiovascular outcomes without adjustment and after adjusting for age and sex and multiple co-variates. The increased risk associated with a higher baseline resting heart rate is most obvious in patients with previous macrovascular complications (fully adjusted HR for death 1.79 for upper [mean 91 bpm] v lowest [mean 58 bpm] fifth of resting heart rate in this sub-group, 95% CI 1.28,2.50, p<0.001). Conclusions Among patients with type 2 diabetes, a higher resting heart rate is associated with increased risk of death and cardiovascular complications. It remains unclear whether a higher heart rate directly mediates the increased risk or is a marker for other factors that determine a poor outcome. PMID:22286552

Hillis, G. S.; Woodward, M.; Rodgers, A.; Chow, C.; Li, Q.; Zoungas, S.; Patel, A.; Webster, R.; Batty, G. D.; Ninomiya, T.; Mancia, G.; Poulter, N. R.; Chalmers, J.

2014-01-01

269

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 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

270

The correlation between psychological intervention and heart rate,systolic pressure in patients of cervical cancer treated with interventional chemoembolization  

International Nuclear Information System (INIS)

Objective: To discuss the effect of psychological intervention on the heart rate, systolic pressure of the patients with cervical cancer who are treated with interventional chemoembolization. Methods: Eighty patients with cervical cancer were randomly and equally divided into two groups. Transcatheter arterial chemoembolization (TACE) was performed in all cases. Patients in study group (n=10) received systemic psychological intervention 30 minutes before TACE. The heart rate and systolic pressure of the patients were measured when TACE started. The results were compared with that obtained at the time of admission. Patients in control group (n=10) did not receive systemic psychological intervention before TACE and their heart rate and systolic pressure were measured in the same way as in study group. Results: At the time TACE started the heart rate and systolic pressure of the patients in study group were significantly lower than that in control group (P < 0.05). Conclusion: Preoperative psychological intervention is very helpful for reducing psychological stress and mental tension,in stabilizing heart rate and systolic pressure of the patients with cervical cancer who are treated with TACE. (authors)

271

Heart Rate Variability in Patients with Chronic Obstructive Pulmonary Disease Treated by Noninvasive Mechanic Ventilation  

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Full Text Available Aims: This study aimed to investigate heart rate variability (HRV of patients with severe COPD who are treated by noninvasive mechanic ventilation (NIMV.Patients and Method: Twenty-seven patient (58±8 years, 9 F with severe COPD treated by nocturnal NIMV at home and 23 sex and age matched volunteers (56±8 years, 11 F who has not dyspnea as a control group recruited in the study. Subjects underwent spirometry, blood gas analysis, transthoracic echocardiography, 24 hours ambulatory ECG analysis. Time domain HRV analysis performed from ambulatory ECG records. Results: 52% of patients at NYHA functional class II, 36% at class III, and 12% at class IV when they have been treated by NIMV. Groups were similar for age and sex (p>0.05 for both. Heart rates of patients were higher significantly than controls’ (p0.05. But, systolic pulmonary pressures were higher of COPD group (p<0.01. 24 hours heart rate was higher, and standard deviation of normal R-R intervals (SDNN 24 hours, SDNN night, SDNN day, SDNN index (SDNNI and standard deviation of mean R-R intervals (SDANNI values were lower in COPD group significantly. SDNN was inversely correlated with duration of daily NIMV usage, intensive care unit administration and entubation rate and PaCO2. SDNNI was inversely correlated with functional class, duration of daily NIMV usage, intensive care unit administration rate and PaCO2. Else, SDNNI was correlated with predicted forced vital capacity % (FVC% and predicted forced expiratory volume at 1 second % (FEV1%.Conclusion: Time domain HRV decreases in patients with severe COPD. Decrease is correlated with severity of disease, and it presents in despite of the chronic nocturnal NIMV application. These patients have high risk for cardiovascular morbidity and mortality and should be monitored and manegement for cardiovascular events.

Zekeriya Küçükdurmaz

2011-08-01

272

Heart rate after cardiac transplantation-lessons from the tortoise and the shrew.  

Science.gov (United States)

There is a striking consistency in the total number of heart beats accrued over a lifetime across a range of animal species despite vast differences in size. Moreover, an inverse relationship is observed between heart rate and lifespan, leading to speculation that elevated heart rate could significantly affect longevity. It is the aim of this review to analyze heart rate as a contributing factor in defining the functional lifespan of the transplanted human heart, which may unavoidably determine the longevity of the recipient. Sinus tachycardia occurs as a result of sympathetic/parasympathetic denervation, an unavoidable consequence of transplantation. The effect of elevated heart rate in this cohort has been scarcely reported. We highlight herein multitudinous mechanisms whereby elevated heart rate accelerates the deterioration in cardiac function and arterial elasticity due to injury and stress accumulation. Additionally, we propose a significant role for heart rate in confounding the alloimmune response. Tachycardia exacerbates injurious episodes of myocardial ischemia and significantly increases the production of reactive oxygen species via increased metabolism. These factors promote immune infiltration and activation, contributing to acute and chronic rejection. Further research is required to assess the potential therapeutic benefits of heart rate reduction. PMID:23104250

Critchley, William R; Yonan, Nizar; Shaw, Steven M; Fildes, James E

2013-01-27

273

Entertainment Capture through Heart Rate Activity in Physical Interactive Playgrounds  

DEFF Research Database (Denmark)

An approach for capturing and modeling individual entertainment (“fun”) 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 children’s physiological signals, an estimator of the degree to which games provided by the playground engage the players. For this purpose children’s heart rate (HR) signals, and their expressed preferences of how much “fun” particular game variants are, are obtained from experiments using games implemented on the Playware playground. A comprehensive statistical analysis shows that children’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 (p?value 6 · 10?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

274

Effect of Wireless Network Radiation on Heart Rate Variability  

Directory of Open Access Journals (Sweden)

Full Text Available The health risk associated with the increased exposure to wireless network devices like Mobile Phones, Wi-Fi etc, had been area of concern. In this paper, the effects of wireless network radiations (WNR on Heart Rate Variability (HRV had been investigated. The two non-linear indices namely i Approximate Entropy (ApEn ii Detrended Fluctuation Analysis (DFA had been used for deciphering the hidden dynamics of HRV. The study comprised of 19 healthy male subjects in the age group of 23±4.3 (mean ± std dev years. The Electrocardiogram (ECG of each subject obtained under three different WNR exposure modes namely i Least or minimum exposure: when WNR level is 0.49±0.12 mW/m2 ii Moderate exposure: when WNR level is 2.08±0.27 mW/m2 iii Maximum or calling mode exposure: when WNR level is 1.65±0.32 W/m2. The results indicate that there is a significant increase in DFA scaling exponent when the WNR level changed from minimum to maximum value, as p-value <0.05, whereas the change in mean value of ApEn was not significant due to higher standard deviation among all the subjects. The WNR exposure caused changes in HRV indices and it varied with WNR level, but all the changes cannot be considered as p values were higher.

Barjinder Singh Saini

2014-01-01

275

Kubios HRV--heart rate variability analysis software.  

Science.gov (United States)

Kubios HRV is an advanced and easy to use software for heart rate variability (HRV) analysis. The software supports several input data formats for electrocardiogram (ECG) data and beat-to-beat RR interval data. It includes an adaptive QRS detection algorithm and tools for artifact correction, trend removal and analysis sample selection. The software computes all the commonly used time-domain and frequency-domain HRV parameters and several nonlinear parameters. There are several adjustable analysis settings through which the analysis methods can be optimized for different data. The ECG derived respiratory frequency is also computed, which is important for reliable interpretation of the analysis results. The analysis results can be saved as an ASCII text file (easy to import into MS Excel or SPSS), Matlab MAT-file, or as a PDF report. The software is easy to use through its compact graphical user interface. The software is available free of charge for Windows and Linux operating systems at http://kubios.uef.fi. PMID:24054542

Tarvainen, Mika P; Niskanen, Juha-Pekka; Lipponen, Jukka A; Ranta-Aho, Perttu O; Karjalainen, Pasi A

2014-01-01

276

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

277

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

278

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 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

279

The significance of fetal heart rate decelerations during nonstress testing.  

Science.gov (United States)

Over a 9-month time span, eight gravid women at high risk had fetal heart rate decelerations on nonstress tests (NSTs). This form of antepartum evaluation, the standard at our institution, was performed 918 times on 476 women during this period. Decelerations were required to be between 1 and 10 minutes in duration and less than 90 bpm, or greater than 40 bpm below baseline, for inclusion. Of the eight women (1.7% of the total tested), four had reactive and four nonreactive NSTs. All eight had contraction stress tests (CSTs) that were negative by definition. Of four women allowed to labor, two (50%) required cesarean section for fetal distress. Two instances of fetal death (25%) occurred during observation periods of 36 and 48 hours. Two infants were growth retarded, and two had abnormal cord positions. NSTs showing decelerations of this type, regardless of reactivity or of follow-up CST, are abnormal and should be viewed with alarm. In term pregnancy, such fetuses should be delivered. In preterm pregnancy with nonreactive NSTs, decelerations may also be valid grounds for delivery. Some discrimination is possible in preterm pregnancies when the NST is reactive. PMID:6476042

Bourgeois, F J; Thiagarajah, S; Harbert, G M

1984-09-15

280

Correlation between heart rate and performance during Olympic windsurfing competition.  

Science.gov (United States)

The aim of this study was to examine the heart rate (HR) response to Olympic windsurfing competition and to check if there was any correlation between racing HR, performance, and the variables measured during laboratory maximal exercise. Ten elite windsurfers [age: 20.93 (3.46) years; height: 178.10 (6.34) cm; body mass: 66.79 (5.90) kg] performed a laboratory maximal oxygen consumption (.VO(2max)) trial and national windsurf competitions wearing a HR monitor. One hundred and forty-three individual races were examined. Racing HR was expressed as a percentage of (1) HR(max) (maximal treadmill HR) and (2) HR(reserve) (HR(max)-HR(rest)). The performance (racing classification: RC, which is inversely proportional to performance) was significantly correlated to the racing HR response in both light wind (LW): LW-RC=-0.12(%HR(reserve))+13.03; r=-0.71, r(2)=0.50, pwindsurfing performances are highly dependent on the capacity of the athlete to maintain a high HR for long periods of time. Furthermore, windsurfing is highly dependent on the athlete's physical fitness level as shown by the correlations between racing HRs and laboratory physiological variables. PMID:12682836

Chamari, Karim; Moussa-Chamari, Imen; Galy, Olivier; Chaouachi, Mustapha; Koubaa, Donia; Hassen, Chokri Ben; Hue, Olivier

2003-05-01

 
 
 
 
281

Stochastic time series analysis of fetal heart-rate variability  

Science.gov (United States)

Fetal Heart Rate(FHR) is one of the important features of fetal biophysical activity and its long term monitoring is used for the antepartum(period of pregnancy before labour) assessment of fetal well being. But as yet no successful method has been proposed to quantitatively represent variety of random non-white patterns seen in FHR. Objective of this paper is to address this issue. In this study the Box-Jenkins method of model identification and diagnostic checking was used on phonocardiographic derived FHR(averaged) time series. Models remained exclusively autoregressive(AR). Kalman filtering in conjunction with maximum likelihood estimation technique forms the parametric estimator. Diagnosrics perfonned on the residuals indicated that a second order model may be adequate in capturing type of variability observed in 1 up to 2 mm data windows of FHR. The scheme may be viewed as a means of data reduction of a highly redundant information source. This allows a much more efficient transmission of FHR information from remote locations to places with facilities and expertise for doser analysis. The extracted parameters is aimed to reflect numerically the important FHR features. These are normally picked up visually by experts for their assessments. As a result long term FHR recorded during antepartum period could then be screened quantitatively for detection of patterns considered normal or abnonnal. 1.

Shariati, M. A.; Dripps, J. H.

1990-06-01

282

Spectral analysis of heart rate variability in bronchial asthma patients.  

Science.gov (United States)

The study was carried in the Departments of Physiology and Medicine at S.M.S. Medical College, Jaipur. Thirty patients of bronchial asthma, aged 20-30 years attending outpatient clinics of S.M.S. Hospital and thirty healthy volunteers were recruited in the present study for spectral analysis of Heart Rate Variability (HRV) using impedance peripheral pulse in the right forearm. Two spectral components were recorded namely high frequency (HF) component (0.15-0.4 Hz), an indicator of vagal efferent activity and low frequency (LF) component (0.04-0.15 Hz), replicator of composite sympatho-vagal interplay. These components were analyzed as LF nu (Low Frequency normalized unit), HF nu (High Frequency normalized unit) and LF/HF ratio. Low frequency component in absolute units of the asthmatic patients differed insignificantly (P > 0.05) from LF of the subjects, whereas the same calculated as normalized units was found to be significantly low in the patient group (P different in patient and control groups (P > 0.05). It was concluded that a significantly raised central vagal outflow and a concomitant significantly low central sympathetic efferent could be appreciated in asymptomatic asthmatic patients as compared to that in the control group. This deranged sympathovagal interplay with parasympathetic dominance could be a plausible pathophysiological mechanism leading to airway obstruction, the hallmark of bronchial asthma. PMID:23781652

Gupta, Jitendra; Dube, Amitabh; Singh, Virendra; Gupta, R C

2012-01-01

283

Heart rate variability interventions for concussion and rehabilitation.  

Science.gov (United States)

The study of heart rate variability (HRV) has emerged as an essential component of cardiovascular health, as well as a physiological mechanism by which one can increase the interactive communication between the cardiac and the neurocognitive systems (i.e., the body and the brain). It is well-established that lack of HRV implies cardiopathology, morbidity, reduced quality-of-life, and precipitous mortality. On the positive, optimal HRV has been associated with good cardiovascular health, autonomic nervous system (ANS) control, emotional regulation, and enhanced neurocognitive processing. In addition to health benefits, optimal HRV has been shown to improve neurocognitive performance by enhancing focus, visual acuity and readiness, and by promoting emotional regulation needed for peak performance. In concussed athletes and soldiers, concussions not only alter brain connectivity, but also alter cardiac functioning and impair cardiovascular performance upon exertion. Altered sympathetic and parasympathetic balance in the ANS has been postulated as a critical factor in refractory post concussive syndrome (PCS). This article will review both the pathological aspects of reduced HRV on athletic performance, as well as the cardiovascular and cerebrovascular components of concussion and PCS. Additionally, this article will review interventions with HRV biofeedback (HRV BFB) training as a promising and underutilized treatment for sports and military-related concussion. Finally, this article will review research and promising case studies pertaining to use of HRV BFB for enhancement of cognition and performance, with applicability to concussion rehabilitation. PMID:25165461

Conder, Robert L; Conder, Alanna A

2014-01-01

284

Vagal control of heart rate is modulated by extracellular potassium.  

Science.gov (United States)

Heart rate (HR) recovery from heavy exercise is associated with a shift in cardiac sympatho-vagal balance and a transient hypokalaemia. Since changes in extracellular potassium ([K+]0) affect membrane currents in the sino-atrial node, in particular the acetylcholine-activated potassium current (I(K,ACh)), the hyperpolarization-activated current (I(f)) and the L-type calcium current (I(Ca,L)), we investigated whether mimicking [K+]0 concentrations seen during and immediately after exercise could directly modulate the HR response to vagal nerve stimulation (VNS) in the isolated guinea-pig atria preparation pre-stimulated with noradrenaline (NA, 1 microM). Lowering [K+]0 from 4 to 3 mM significantly enhanced the HR response to VNS (5 Hz, 5 V, 30 s, deltaHR 84.5 +/- 14.1 bpm and 119.3 +/- 18.2 bpm, respectively). Increasing [K+]0 to 8 or 10 mM significantly decreased the drop in HR with VNS in comparison to the response to 3 mM K+ Tyrode (deltaHR 56.4 +/- 9.1 bpm and 52.1 +/- 8.7 bpm, respectively). These results could be simulated using the OXSOFT heart sino-atrial node computer model by activating I(K,ACh) during changes in [K+]0. However, changing [K+]0 in the model had no significant effect on the decrease in beating frequency brought about by decreasing I(f) or I(Ca,L). We conclude that the magnitude of the decrease in HR with VNS is enhanced in low [K +]0 and reduced in high [K+]0. The increased efficacy of cardiac vagal activation in low [K+]0 might therefore facilitate the drop in HR after heavy exercise where there is a transient hypokalaemia. Modelling suggests this result may be explained by the effects of changes in [K+]0 on the current-voltage relationship for I(K,ACh). PMID:10580298

Sears, C E; Noble, P; Noble, D; Paterson, D J

1999-09-24

285

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

Directory of Open Access Journals (Sweden)

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

286

Heart Rate Responses of Coach and Referee to Selected Events During a College Basketball Game.  

Science.gov (United States)

Heart rate responses of a coach and a referee were continuously monitored by radio telemetry during a college basketball game. Analysis of data indicated that the heart rate of the coach was higher than that of the official for most of the contest. Events...

A. E. Coleman

1972-01-01

287

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

Science.gov (United States)

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

288

Heart rate fluctuations in post-operative and brain-death patients  

Science.gov (United States)

The power spectra of heart rate in patients receiving intensive care were calculated and the relation between gain and frequency discussed. 1/f fluctuations in heart rate can be observed in both post-operative and brain-death patients in the intensive care unit. These results suggested that 1/f fluctuations are a fundamental human phenomenon.

Tamura, Toshiyo; Nakajima, Kazuki; Maekawa, Tuyoshi; Soejima, Yoshiyuki; Kuroda, Yasuhiro; Tateishi, Akio

1993-08-01

289

Cardiovascular Fitness and Maximal Heart Rate Differences Among Three Ethnic Groups.  

Science.gov (United States)

Examination of differences in maximal heart rate and treadmill time among three ethnic groups revealed no significant age-adjusted differences among white, black, and Mexican-American males, and suggested that black females' lower maximal heart rate may be explained by their lower cardiovascular fitness level when compared to those of other…

Farrell, S. W.

1988-01-01

290

Middle School Student's Heart Rates during Different Curricular Activities in Physical Education  

Science.gov (United States)

The purpose of this study was to determine if students' heart rate outcomes in physical education varied as a function of activity and grade. A total of 146 sixth to eighth graders participated in different activities (i.e., walking/jogging, line dancing, soccer, and catch ball). Their average heart rate (AHR) and percentage of time in and above…

Gao, Zan; Hannon, James C.; Carson, Russell L.

2009-01-01

291

Heart rate variability reflects training load and psychophysiological status in young elite gymnasts.  

Science.gov (United States)

In gymnastics, monitoring of the training load and assessment of the psychophysiological status of elite athletes is important for training planning and to avoid overtraining, consequently reducing the risk of injures. The aim of this study was to examine whether heart rate variability (HRV) is a valuable tool to determine training load and psychophysiological status in young elite gymnasts. Six young male elite gymnasts took part in a 10-week observational study. During this period, beat-to-beat heart rate intervals were measured every training day in weeks 1, 3, 5, 7, and 9. Balance, agility, upper limb maximal strength, lower limb explosive, and elastic power were monitored during weeks 2, 4, 6, 8, and 10. Training load of each training session of all 10 weeks was assessed by session rating of perceived exertion (RPE) and psychophysiological status by Foster's index. Morning supine HRV (HF% and LF%/HF%) correlated with the training load of the previous day (r = 0.232, r = -0.279, p < 0.05 ). Morning supine to sitting HRV difference (mean R wave to R wave interval (RR), mean heart rate, HF%, SD1) correlated with session RPE of the previous day (r = -0.320, r = 0.301, p < 0.01; r = 0.265, r = -0.270, p < 0.05) but not with Foster's index. Training day/reference day HRV difference (mean RR, SD1) showed the best correlations with session RPE of the previous day (r = -0.384, r = -0.332, p < 0.01) and Foster's index (r = -0.227, r = -0.260, p < 0.05). In conclusion, HRV, and in particular training day/reference day mean RR difference or SD1 difference, could be useful in monitoring training load and psychophysiological status in young male elite gymnasts. PMID:23364293

Sartor, Francesco; Vailati, Emanuele; Valsecchi, Viola; Vailati, Fulvio; La Torre, Antonio

2013-10-01

292

HEART RATE RESPONSE TO GAME-PLAY IN PROFESSIONAL BASKETBALL PLAYERS  

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Full Text Available Introduction. The effectiveness of using the heart rate (HR as an indicator of exercise intensity to monitor basketball training has been the subject of intense investigation. However, recent new regulations and a trend towards a more conditional game have prompted a need to revise field study procedures and demanded the increased specialization of game positions. Objectives. Five preseason matches played by a Profesional men’s Spanish league team LEB (Club Baloncesto León were analyzed in terms of the HR response recorded in the four game quarters. Materials and Methods. Heart rates were recorded using Polar Team® monitors in a group of 8 players, whose playing positions were point guard (n=2, forward (n=3 or center (n=3. We recorded maxima (HRmax and means (HRmean for each player and also expressed rates as percentages of the individual maximum HR recorded in the 5 games (%HRmax and %HRmean. Results. For the point guards, forwards and centers, respectively, HRmax (in beats•min were 186±11.7, 176±8.3 and 177±7.7; and HRmean (beats•min-1 were 163±14.3, 151±10.3 and 155±9.4. While similar HRmax were observed in each quarter, significant differences were detected between the %HRmax values for the point guards versus the forwards or centers (P<0.0001 and P<0.05, respectively. Conclusion. Our findings indicate that point guards show the highest HR and forwards the lowest. HRmax and %HRmax values were high during the first quarter and continued to increase during the game, peaking in the final quarter. Key words: Basketball, Heart rate, Game positions, Preseason.

Vaquera, A.

2008-01-01

293

The Rate of Addiction in Parents of Toddlers With Congenital Heart Disease  

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Background Opium abuse is one of the widespread social problems, and one of the most worrying aspects of it is the effect of parents’ drug abuse on the fetus. Objectives The present study has investigated the correlation between opium abuse during pregnancy in mothers with congenital heart defects in their children. Materials and Methods From early 2009 to late 2011, for two consecutive years in specialized pediatric center of Zahedan Medical University, 225 of children suffering from congenital heart defects were examined and compared with 480 healthy ones for mother opium dependency. The final data were analyzed by student t-test and ?2 in SPSS software and the two groups were compared in terms of their parents’ addiction to opium. Results From 225 children under study 23.5% had addicted parents based on the variables of the study but the rate was only 2.3 for the control group. The difference between these two groups was significant and the most common form of heart disease was congenital ventricular septal defect. Conclusions Opium has teratogenic effect on cardiovascular system. PMID:24971255

Sahramian, Iraj; Noori, Noor Mohammad; Moradi, Abdolvahab; Forghani, Forugh; Sharafi, Elham

2013-01-01

294

Diagnostic accuracy of dual-source CT coronary angiography: The effect of average heart rate, heart rate variability, and calcium score in a clinical perspective  

International Nuclear Information System (INIS)

Background: Dual-source CT coronary angiography (CTCA) has been used to detect coronary artery disease; however, the factors with potential to affect its diagnostic accuracy remain to be defined. Purpose: To prospectively evaluate the accuracy of dual-source CTCA in diagnosing coronary artery stenosis according to conventional coronary angiography (CAG), and the effect of average heart rate, heart rate variability, and calcium score on the accuracy of CTCA. Material and Methods: A total of 113 patients underwent both dual-source CTCA and CAG. The results were used to evaluate the findings in dual-source CTCA to assess the accuracy in the diagnosis of =50% (significant stenosis) and >75% (severe stenosis) of coronary artery according to those by CAG. Patients were divided into subgroups according to their heart rate (HR), HR variability (HRV), and calcium score, and the accuracy of CTCA was further evaluated. The chi-square test was used to analyze the difference in sensitivity and specificity for the detection of =50% and >75% coronary stenosis among subgroups. The generalized estimation equation method was used in per-vessel analysis to adjust for within-patient correlation. Results: In all, 113 patients had 338 vessels and 1661 segments evaluated by CAG. Dual-source CTCA displayed 1527 segments (91.9%). Among them, 1468 segments (calcium score by CAG score 1, n=1018; score 2, n=270; score 3, n=180) were assessable in CTCA. On a per-patient analysis, the sensitivity n a per-patient analysis, the sensitivity and specificity of CTCA were 93.9% and 93.5% for significant stenosis and 86.9% and 98.1% for severe stenosis. On a per-vessel basis, the sensitivity and specificity were 90.2% and 97.1% for significant and 83.3% and 98.1% for severe stenosis. On a per-segment analysis, the sensitivity and specificity were 90.2% and 97.1% for significant and 83.3% and 98.1% for severe stenosis. Average HR had no effect on the sensitivity and specificity of CTCA (P>0.05); whereas HRV and calcium score had some effect on the sensitivity and specificity of CTCA (P<0.05). Conclusion: On a per-patient, per-vessel, and per-segment basis, dual-source CTCA has a high sensitivity and specificity for the diagnosis of coronary artery stenosis. Average HR has no effect on the diagnostic accuracy of CTCA, while HRV and calcium score have a statistically significant effect on the sensitivity and specificity of CTCA

295

Influence of heart rate on image quality of 64-slice spiral computed coronary angiography and optimization on reconstruction of phase window  

International Nuclear Information System (INIS)

Objective: To evaluate the influence of heart rate on the image quality of 64-slice spiral computed coronary angiography (MSCTCA) and optimize the image reconstruction window. Methods: According to the heart rate, 86 patients were classified into 5 groups: group A, the heart rate ?60 beat per minute(BMP); group B,61-70BMP, group C,71-80BMP, and group D>80BMP. The image quality of MSCTCA was scored 5 grades from 1-5 according to heart motion artifact. The influences of heart rate and reconstruction phase on the image quality of MSCTCA were evaluated. Results: Average heart rate was 64.4 ±10.1BMP. Diagnostic image quality (score>3) was attained in 277 of 344 segments at the best reconstruction interval. There was a significant corxelation between average heart rate and image quality, but there was no difference between relative delay (%) reconstruction and absolute delay (ms) reconstruction on the image quality. Conclusion: Reducing average heart rate is beneficial for improving the image quality. (authors)

296

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

297

Harmful Effects of Mobile Phone Waves on Human Heart Beat Rate  

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Full Text Available Concern about human exposure to radiofrequency (RF is not new. The conveniences and satisfaction derived in the use of GSM mobile phone is being threatened by claims of adverse effects on human health by radiation coming from this device. This radiation belongs to the type called non-ionizing radiation the health hazard of which remains debatable. Research has not been carried out on possible effect this device might have on human health and no experimental proof, based on data obtained within India, exist to substantiate any claim. Safety standards exist for radiation from cell phone but these are not reassuring. This paper investigates any possible effect of mobile phone radiation on human heart rate and then come out with conclusion based on experimental proof. Over forty human subjects twenty male and twenty female were monitored by measuring their pulse rate under three exposure criteria. In one of the radiation tests, the phone used was put in vibration mode in order to determine subjects were not just responding to vibration. It was found out pulse rate do not change significantly when subjects were exposed to phone radiation. However, the percentage decrease recorded by people of age 40 years and above, even though barely above 1% makes it advisable that people of age 40 years and above should avoid keeping mobile phones close to the heart.

Mushtaq Ahmed Bhat,

2013-08-01

298

Gender- and age-related differences in heart rate dynamics: are women more complex than men?  

Science.gov (United States)

OBJECTIVES. This study aimed to quantify the complex dynamics of beat-to-beat sinus rhythm heart rate fluctuations and to determine their differences as a function of gender and age. BACKGROUND. Recently, measures of heart rate variability and the nonlinear "complexity" of heart rate dynamics have been used as indicators of cardiovascular health. Because women have lower cardiovascular risk and greater longevity than men, we postulated that there are important gender-related differences in beat-to-beat heart rate dynamics. METHODS. We analyzed heart rate dynamics during 8-min segments of continuous electrocardiographic recording in healthy young (20 to 39 years old), middle-aged (40 to 64 years old) and elderly (65 to 90 years old) men (n = 40) and women (n = 27) while they performed spontaneous and metronomic (15 breaths/min) breathing. Relatively high (0.15 to 0.40 Hz) and low (0.01 to 0.15 Hz) frequency components of heart rate variability were computed using spectral analysis. The overall "complexity" of each heart rate time series was quantified by its approximate entropy, a measure of regularity derived from nonlinear dynamics ("chaos" theory). RESULTS. Mean heart rate did not differ between the age groups or genders. High frequency heart rate power and the high/low frequency power ratio decreased with age in both men and women (p age and was higher in women than men (p gender-as well as age-related differences in heart rate dynamics. Whether these gender differences are related to lower cardiovascular disease risk and greater longevity in women requires further study.

Ryan, S. M.; Goldberger, A. L.; Pincus, S. M.; Mietus, J.; Lipsitz, L. A.

1994-01-01

299

Gender- and age-related differences in heart rate dynamics: are women more complex than men?  

Science.gov (United States)

OBJECTIVES. This study aimed to quantify the complex dynamics of beat-to-beat sinus rhythm heart rate fluctuations and to determine their differences as a function of gender and age. BACKGROUND. Recently, measures of heart rate variability and the nonlinear "complexity" of heart rate dynamics have been used as indicators of cardiovascular health. Because women have lower cardiovascular risk and greater longevity than men, we postulated that there are important gender-related differences in beat-to-beat heart rate dynamics. METHODS. We analyzed heart rate dynamics during 8-min segments of continuous electrocardiographic recording in healthy young (20 to 39 years old), middle-aged (40 to 64 years old) and elderly (65 to 90 years old) men (n = 40) and women (n = 27) while they performed spontaneous and metronomic (15 breaths/min) breathing. Relatively high (0.15 to 0.40 Hz) and low (0.01 to 0.15 Hz) frequency components of heart rate variability were computed using spectral analysis. The overall "complexity" of each heart rate time series was quantified by its approximate entropy, a measure of regularity derived from nonlinear dynamics ("chaos" theory). RESULTS. Mean heart rate did not differ between the age groups or genders. High frequency heart rate power and the high/low frequency power ratio decreased with age in both men and women (p gender-as well as age-related differences in heart rate dynamics. Whether these gender differences are related to lower cardiovascular disease risk and greater longevity in women requires further study.

Ryan, S. M.; Goldberger, A. L.; Pincus, S. M.; Mietus, J.; Lipsitz, L. A.

1994-01-01

300

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

 
 
 
 
301

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

302

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.

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

2014-05-01

303

Validation of heart rate extraction through an iPhone accelerometer.  

Science.gov (United States)

Ubiquitous medical technology may provide advanced utility for evaluating the status of the patient beyond the clinical environment. The iPhone provides the capacity to measure the heart rate, as the iPhone consists of a 3-axis accelerometer that is sufficiently sensitive to perceive tiny body movements caused by heart pumping. In this preliminary study, an iPhone was tested and evaluated as the reliable heart rate extractor to use for medical purpose by comparing with reference electrocardiogram. By comparing the extracted heart rate from acquired acceleration data with the extracted one from ECG reference signal, iPhone functioning as the reliable heart rate extractor has demonstrated sufficient accuracy and consistency. PMID:22255524

Kwon, Sungjun; Lee, Jeongsu; Chung, Gih Sung; Park, Kwang Suk

2011-01-01

304

Prostacyclin can either increase or decrease heart rate depending on the basal state.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

1 The influence of the basal heart rate on the change in rate induced by prostacyclin (PGI2) was investigated in beagles anaesthetized with chloralose. 2 In male dogs with a low basal heart rate (less than 100 beats/min) PGI2, in doses up to 0.5 microgram/kg intravenously, induced hypotension and tachycardia. 3 In contrast, PGI2-induced hypotension was accompanied by bradycardia when either the basal heart rate was increased (greater than 130 beats/min) with isoprenaline or nitroprusside, or ...

Chiavarelli, M.; Moncada, S.; Mullane, K. M.

1982-01-01

305

Heart Rate Analysis and Telemedicine: New Concepts & Maths  

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Full Text Available Our paper deals with some new aspects of ambulatory (Holter ECG monitoringextending its indications and using for risk management purpose. Remote sensing consistsof the transmittal of patient information, such as ECG, x-rays, or patient records, from aremote site to a collaborator in a distant site. Our earlier developed internet based ECGsystem was unique for on/off-line analysis of long-term ECG registrations. After the 5-yearexperience in a smaller region of Budapest, Hungary involving a municipal hospital andthe surrounding outpatient cardiology departments and general practitioners, we decidedto integrate into our new ECG equipment, the CardioClient the results. In the first clinicalstudy of the four was a wavelet, non-linear heart rate analysis in sudden cardiac deathpatients using the Internet and the GPRS mobile communication. After the wavelettransformation by the Haar wavelet and the Daubechies 10-tap wavelet, the phase-space ofthe wavelet-coefficient standard deviation and the scale parameters showed an excellentseparation in the scale-range of 3-6 between the two groups: in that region, the averagescaling exponents was 0.14+-0.04 for Group-A, and 1.22+-0.27 for Group-B (p<0.001. Inthe next study, we used the Internet database of long-term ambulatory, mobile, GPRSelectrocardiograms for the for risk stratification of patients through the cardiovascularcontinuum. From our ambulatory mobile GPRS ECG database the following a priorigroups were defined after a 24 months follow-up: G1: N=227 patients (without manifestcardiovascular disease, clusterized ‘boxes’ based on the age, sex, cholesterol level,diabetes, hypertension; G2: N=89 patients (postinfarction group; G3: N=66 (patientswith chronic heart failure with (+ or without (-: all-cause death (acD, myocardialinfarction (MI, malignant ventricular arrhythmia (MVA, sudden cardiac death (SCD.The actual vs. predicted values were analyzed with chi-square test. The best significancelevels (p<0.001 were found with method in G1/MI+, G2/SCD+, G3/acD+, G3/SCD+groups. In the third study a wavelet analysis of late potentials based on long-term, highresolution,mobile, GPRS ECG data was performed. These pathological changes were alsodetected by the Haar and Daubechies_4 wavelets, but in a narrower space (110-128 msand 180-240 and with lesser significance (p<0.01. Late potentials were found in Group-A(N=21 in 18 cases with Morlet, 16 with Haar, 19 with Daub-4 analysis, and in 15 casesusing all the 3 waves; for Group-B the data were 5, 9, 8, 5, respectively. In the fourthclinical study the prognostic value of the nonlinear dynamicity measurement of atrialfibrillation waves detected by GPRS internet long-term ECG monitoring were analyzed.The multivariate discriminant model selects the best parameters stepwise, the entry orremoval based on the minimalization of the Wilks’ lambda. Three variables remainedfinally: x1 = CI mean-value at log r=-1.0 (m9-14, x2 = CI mean-value at log r=-0.5 (m12-17, and x3 = CD_cg. The Wilks’ lambda was 0.011, chi-square 299.68, significancy:p<0,001.

Sándor Khoór

2008-01-01

306

Atrial fibrillation detection by heart rate variability in Poincare plot  

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Full Text Available Abstract Background Atrial fibrillation (AFib is one of the prominent causes of stroke, and its risk increases with age. We need to detect AFib correctly as early as possible to avoid medical disaster because it is likely to proceed into a more serious form in short time. If we can make a portable AFib monitoring system, it will be helpful to many old people because we cannot predict when a patient will have a spasm of AFib. Methods We analyzed heart beat variability from inter-beat intervals obtained by a wavelet-based detector. We made a Poincare plot using the inter-beat intervals. By analyzing the plot, we extracted three feature measures characterizing AFib and non-AFib: the number of clusters, mean stepping increment of inter-beat intervals, and dispersion of the points around a diagonal line in the plot. We divided distribution of the number of clusters into two and calculated mean value of the lower part by k-means clustering method. We classified data whose number of clusters is more than one and less than this mean value as non-AFib data. In the other case, we tried to discriminate AFib from non-AFib using support vector machine with the other feature measures: the mean stepping increment and dispersion of the points in the Poincare plot. Results We found that Poincare plot from non-AFib data showed some pattern, while the plot from AFib data showed irregularly irregular shape. In case of non-AFib data, the definite pattern in the plot manifested itself with some limited number of clusters or closely packed one cluster. In case of AFib data, the number of clusters in the plot was one or too many. We evaluated the accuracy using leave-one-out cross-validation. Mean sensitivity and mean specificity were 91.4% and 92.9% respectively. Conclusions Because pulse beats of ventricles are less likely to be influenced by baseline wandering and noise, we used the inter-beat intervals to diagnose AFib. We visually displayed regularity of the inter-beat intervals by way of Poincare plot. We tried to design an automated algorithm which did not require any human intervention and any specific threshold, and could be installed in a portable AFib monitoring system.

Jeon Moongu

2009-12-01

307

Effects of melatonin and ethanol on the heart rate of Daphnia magna  

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Full Text Available Melatonin, an endogenous hormone that may regulate circadian rhythms by modulating cholinergic activity, is increasing in popular use as a natural treatment for sleep disorders. However, the effects of melatonin on the human heart are not well characterized, and the consequences of combining alcohol with melatonin are unknown. The myogenic heart of the water flea Daphnia magna (D. magna is regulated by inhibitory cholinergic neurons that modulate cardiac function, including heart rate. D. magna is a useful model organism for cardiovascular function, due to its physical transparency and susceptibility to cardioactive drugs known to affect the human heart. In this study, the effects of immersion in 10 mg/L melatonin and 5% ethanol on the heart rate of D. magna were quantified. Two-hour exposure to melatonin caused a significant decrease in heart rate, from 228 ± 2 bpm to 167 ± 8 bpm. Six-minute immersion in ethanol also significantly depressed the heart rate to 176 ± 10 bpm. Pretreatment with melatonin prior to the addition of ethanol resulted in a greater decrease in heart rate (89 ± 7 bpm than ethanol or melatonin alone. These findings indicate that melatonin and alcohol may combine to cause a greater depressive effect on cardiac function.

Rebecca Kohn

2009-01-01

308

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english 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 exp [...] ressed 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.

T., Walther; N., Wessel; N., Kang; A., Sander; C., Tschöpe; H., Malberg; M., Bader; A., Voss.

2000-01-01

309

Evidence that BDNF regulates heart rate by a mechanism involving increased brainstem parasympathetic neuron excitability.  

Science.gov (United States)

Autonomic control of heart rate is mediated by cardioinhibitory parasympathetic cholinergic neurons located in the brainstem and stimulatory sympathetic noradrenergic neurons. During embryonic development the survival and cholinergic phenotype of brainstem autonomic neurons is promoted by brain-derived neurotrophic factor (BDNF). We now provide evidence that BDNF regulates heart rate by a mechanism involving increased brainstem cardioinhibitory parasympathetic activity. Mice with a BDNF haploinsufficiency exhibit elevated resting heart rate, and infusion of BDNF intracerebroventricularly reduces heart rate in both wild-type and BDNF+/- mice. The atropine-induced elevation of heart rate is diminished in BDNF+/- mice and is restored by BDNF infusion, whereas the atenolol-induced decrease in heart rate is unaffected by BDNF levels, suggesting that BDNF signaling enhances parasympathetic tone which is diminished with BDNF haploinsufficiency. Whole-cell recordings from pre-motor cholinergic cardioinhibitory vagal neurons in the nucleus ambiguus indicate that BDNF haploinsufficiency reduces cardioinhibitory vagal neuron activity by increased inhibitory GABAergic and diminished excitatory glutamatergic neurotransmission to these neurons. Our findings reveal a previously unknown role for BDNF in the control of heart rate by a mechanism involving increased activation of brainstem cholinergic parasympathetic neurons. PMID:24475741

Wan, Ruiqian; Weigand, Letitia A; Bateman, Ryan; Griffioen, Kathleen; Mendelowitz, David; Mattson, Mark P

2014-05-01

310

Heart rate variability analysis in sheep affected by transmissible spongiform encephalopathies  

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Full Text Available Abstract Background The function of the autonomic nervous system can be assessed by determining heart rate variability (HRV, which is impaired in some brainstem diseases in humans. Transmissible spongiform encephalopathies (TSEs in sheep are diseases characterised by accumulation of disease-associated prion protein in the brainstem, including nuclei of the parasympathetic nervous system. This study was undertaken to assess whether analysis of HRV can be used as an aid in the diagnosis of TSEs in clinically affected, naturally or experimentally infected sheep. Findings When HRV indices were compared between 41 clinical TSE cases (18 sheep infected with scrapie and 23 sheep infected with bovine spongiform encephalopathy, 11 control sheep and six sheep reported as scrapie suspects or dosed with BSE brain homogenate, which were not confirmed as TSE cases by postmortem tests, no significant differences were found between the groups. Median heart rate was significantly different but only when sheep were grouped by gender: it was higher in female TSE cases than in control sheep and higher in female than castrated male ovine classical BSE cases. Conclusions HRV analysis was not useful as a diagnostic aid for TSEs of sheep.

Konold Timm

2011-12-01

311

Heart rate variability of young table tennis players with the use of the multiball training  

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Full Text Available The purpose of this study was to evaluate the heart rate responses of the 2 multiball table tennis interval training protocols during the competitive period on young table tennis players. Fourteen (n=14 players, aged 12±2yrs participated in this study. participants were randomly divided into 2 training duration groups (15s vs. 30s and were trained under the 2 interval protocols for 6 weeks (3 sessions. w-1. heart rate (hr data was electronically recorded by using the Polar Team System at the completion of each exercise at the 1st and 5th set in the 1st and 6th week. the Wilcoxon signed-rank test was applied in or- der to compare the repeated measurements, whereas spear- man’s rank correlation (? analysis was employed to determine whether the testing parameters are significantly related. From the results it is shown that regarding to the hr both training protocols can simulate the match conditions. In both groups participants’ the footwork exercises with Forehand and Backhand strokes recorded the higher hr (190-210 b.min-1. additionally, significant hr differences were recorded in group a (z=-2.023, p=0.043 in Footwork Forehand Backhand (FtFB. In conclusion, both multiball protocols can generally simulate match conditions supporting the weekly training program of young table tennis players

MICHAIL KATSIKADELIS

2014-10-01

312

Time-domain heart rate variability in coronary artery disease patients affected by thyroid dysfunction.  

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Subclinical hypothyroidism and hyperthyroidism have been recognized as clinical entities with negative effects on the cardiovascular system. Moreover, the effect of treated thyroid dysfunction on parameters associated with the cardiovascular control system has been poorly investigated. In the present study we analyzed time-domain heart rate variability in coronary artery disease (CAD) patients with known thyroid diseases. Twenty-four hour ECG monitoring was performed in 344 patients with coronary artery disease (174 with thyroid dysfunction and 170 without thyroid dysfunction used as a control group), using a 3-channel tape recorder. Time domain parameters of heart rate variability (HRV) were definitely lower both in patients with subclinical hypothyroidism and subclinical hyperthyroidism than in the control group, with statistically significant differences in SDNN, RMSSD, TINN, and mean RR for both subgroups. Furthermore, patients on L-thyroxine treatment and restored euthyroidism had generally higher HRV values than patients with subclinical hypothyroidism, nevertheless SDNN, RMSSD, SDNN index, TINN, and mean RR were significantly lower when compared to those of the control group. Significant differences in HRV were also found between hyperthyroid patients under treatment and control group subjects with respect to RMSSD, TINN, and mean RR values. In conclusion, patients with cardiac disease and known thyroid disease, even when the disease is in the subclinical range or despite treatment, should be regarded as patients at additional risk conveyed by thyroid hormone disturbances. PMID:24463923

Falcone, Colomba; Matrone, Benedetta; Bozzini, Sara; Guasti, Luigina; Falcone, Rossana; Benzi, Alberto; Colonna, Anna; Savulescu, Ioana; Vailati, Alberto; Pelissero, Gabriele

2014-01-01

313

Cardiac Troponin T Levels in Umbilical Cord Blood of Neonates with Abnormal Fetal Heart Rate  

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Full Text Available Objective: Most neonatal encephalopathic disorders appear to be caused by perinatal events. Persistent myocardial ischemia leads to cellular necrosis and release of troponin from cardiac muscles. Fetal distress during labor may be detected by monitoring the fetal heart rate. However little is known about the relationship, if any, that exists between fetal heart rate abnormalities and the fetal cardiac musculature and its function. The aim of this study was to investigate the relationship, if any, of umbilical cord serum levels of cardiac troponin T with fetal bradycardia or late deceleration.Methods: In this cross sectional study, troponin T level in umbilical cord blood of 80 neonates are measured. There were 23 versus 57 fetuses with and without late deceleration or bradycardia.Findings: Level of cardiac troponin T in umbilical blood of neonates with fetal bradycardia or late deceleration was elevated in comparison to neonates without bradycardia or late deceleration. There was no relation between umbilical troponin T level and mode of delivery.Conclusion: Infants with fetal bradycardia or late deceleration during labor had significantly higher cord cardiac troponin T levels. If troponin level is normal, the probability of hypoxia will be very low.

Shiva Rafati

2013-02-01

314

Evaluation of a technique to measure heart rate variability in anaesthetised cats.  

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Analysis of heart rate (HR) and heart rate variability (HRV) are powerful tools to investigate cardiac diseases, but current methods, including 24-h Holter monitoring, can be cumbersome and may be compromised by movement artefact. A commercially available data capture and analysis system was used in anaesthetised healthy cats to measure HR and HRV during pharmacological manipulation of HR. Seven healthy cats were subjected to a randomised crossover study design with a 7 day washout period between two treatment groups, placebo and atenolol (1mg/kg, IV), with the efficacy of atenolol to inhibit ?1 adrenoreceptors challenged by epinephrine. Statistical significance for the epinephrine challenge was set at Pantagonised the tachycardia while not significantly affecting HRV. The increased HR in the placebo group following epinephrine challenge was consistent with a shift of the sympathovagal balance towards a predominantly sympathetic tone. However, the small (but not significant at the critical value) decrease in the normalised high-frequency component (HFnorm) in both groups of cats suggested that epinephrine induced a parasympathetic withdrawal in addition to sympathetic enhancement (increased normalised low frequency component or LFnorm). In conclusion, this model is a highly sensitive and repeatable model to investigate HRV in anaesthetised cats that would be useful in the laboratory setting for short-term investigation of cardiovascular disease and subtle responses to pharmacological agents in this species. PMID:24321367

Khor, Kuan Hua; Shiels, Ian A; Campbell, Fiona E; Greer, Ristan M; Rose, Annie; Mills, Paul C

2014-02-01

315

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

316

The use of heart rate variability in assessing precompetitive stress in high-standard judo athletes.  

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The objective of this study is to examine the sensitivity to and changes in heart rate variability (HRV) in stressful situations before judo competitions and to observe the differences among judo athletes according to their competitive standards in both official and unofficial competitions. 24 (10 male and 14 female) national- and international-standard athletes were evaluated. Each participant answered the Revised Competitive State Anxiety Inventory (CSAI-2R) and their HRV was recorded both during an official and unofficial competition. The MANOVA showed significant main effects of the athlete's standard and the type of competition in CSAI-2R, in HRV time domain, in HRV frequency domain and in HRV nonlinear analysis (psomatic anxiety, cognitive anxiety, heart rate and low-high frequency ratio than national-standard athletes (p<0.05). International-standard athletes have a higher confidence, mean RR interval, standard deviation of RR, square root of the mean squared difference of successive RR intervals, number of consecutive RR that differ by more than 5 ms, short-term variability, long-term variability, long-range scaling exponents and short-range scaling exponent than national-standard judo athletes. In conclusion, international-standard athletes show less pre-competitive anxiety than the national-standard athletes and HRV analysis is sensitive to changes in pre-competitive anxiety. PMID:22972248

Morales, J; Garcia, V; García-Massó, X; Salvá, P; Escobar, R; Buscà, B

2013-02-01

317

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

318

The effects of auditory stimulation with music on heart rate variability in healthy women  

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Full Text Available SciELO Brazil | Language: English Abstract in english OBJECTIVES: There are no data in the literature with regard to the acute effects of different styles of music on the geometric indices of heart rate variability. In this study, we evaluated the acute effects of relaxant baroque and excitatory heavy metal music on the geometric indices of [...] heart rate variability in women. METHODS: We conducted this study in 21 healthy women ranging in age from 18 to 35 years. We excluded persons with previous experience with musical instruments and persons who had an affinity for the song styles. We evaluated two groups: Group 1 (n?=?21), who were exposed to relaxant classical baroque musical and excitatory heavy metal auditory stimulation; and Group 2 (n?=?19), who were exposed to both styles of music and white noise auditory stimulation. Using earphones, the volunteers were exposed to baroque or heavy metal music for five minutes. After the first music exposure to baroque or heavy metal music, they remained at rest for five minutes; subsequently, they were re-exposed to the opposite music (70-80 dB). A different group of women were exposed to the same music styles plus white noise auditory stimulation (90 dB). The sequence of the songs was randomized for each individual. We analyzed the following indices: triangular index, triangular interpolation of RR intervals and Poincaré plot (standard deviation of instantaneous beat-by-beat variability, standard deviation of the long-term RR interval, standard deviation of instantaneous beat-by-beat variability and standard deviation of the long-term RR interval ratio), low frequency, high frequency, low frequency/high frequency ratio, standard deviation of all the normal RR intervals, root-mean square of differences between the adjacent normal RR intervals and the percentage of adjacent RR intervals with a difference of duration greater than 50 ms. Heart rate variability was recorded at rest for 10 minutes. RESULTS: The triangular index and the standard deviation of the long-term RR interval indices were reduced during exposure to both music styles in the first group and tended to decrease in the second group whereas the white noise exposure decreased the high frequency index. We observed no changes regarding the triangular interpolation of RR intervals, standard deviation of instantaneous beat-by-beat variability and standard deviation of instantaneous beat-by-beat variability/standard deviation in the long-term RR interval ratio. CONCLUSION: We suggest that relaxant baroque and excitatory heavy metal music slightly decrease global heart rate variability because of the equivalent sound level.

Adriano L., Roque; Vitor E., Valenti; Heraldo L., Guida; Monica F., Campos; Andre, Knap; Luiz Carlos M., Vanderlei; Lucas L., Ferreira; Celso, Ferreira; Luiz Carlos, de Abreu.

2013-07-01

319

The effects of auditory stimulation with music on heart rate variability in healthy women  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english OBJECTIVES: There are no data in the literature with regard to the acute effects of different styles of music on the geometric indices of heart rate variability. In this study, we evaluated the acute effects of relaxant baroque and excitatory heavy metal music on the geometric indices of [...] heart rate variability in women. METHODS: We conducted this study in 21 healthy women ranging in age from 18 to 35 years. We excluded persons with previous experience with musical instruments and persons who had an affinity for the song styles. We evaluated two groups: Group 1 (n?=?21), who were exposed to relaxant classical baroque musical and excitatory heavy metal auditory stimulation; and Group 2 (n?=?19), who were exposed to both styles of music and white noise auditory stimulation. Using earphones, the volunteers were exposed to baroque or heavy metal music for five minutes. After the first music exposure to baroque or heavy metal music, they remained at rest for five minutes; subsequently, they were re-exposed to the opposite music (70-80 dB). A different group of women were exposed to the same music styles plus white noise auditory stimulation (90 dB). The sequence of the songs was randomized for each individual. We analyzed the following indices: triangular index, triangular interpolation of RR intervals and Poincaré plot (standard deviation of instantaneous beat-by-beat variability, standard deviation of the long-term RR interval, standard deviation of instantaneous beat-by-beat variability and standard deviation of the long-term RR interval ratio), low frequency, high frequency, low frequency/high frequency ratio, standard deviation of all the normal RR intervals, root-mean square of differences between the adjacent normal RR intervals and the percentage of adjacent RR intervals with a difference of duration greater than 50 ms. Heart rate variability was recorded at rest for 10 minutes. RESULTS: The triangular index and the standard deviation of the long-term RR interval indices were reduced during exposure to both music styles in the first group and tended to decrease in the second group whereas the white noise exposure decreased the high frequency index. We observed no changes regarding the triangular interpolation of RR intervals, standard deviation of instantaneous beat-by-beat variability and standard deviation of instantaneous beat-by-beat variability/standard deviation in the long-term RR interval ratio. CONCLUSION: We suggest that relaxant baroque and excitatory heavy metal music slightly decrease global heart rate variability because of the equivalent sound level.

Adriano L., Roque; Vitor E., Valenti; Heraldo L., Guida; Monica F., Campos; Andre, Knap; Luiz Carlos M., Vanderlei; Lucas L., Ferreira; Celso, Ferreira; Luiz Carlos, de Abreu.

320

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

 
 
 
 
321

Correlates of heart rate recovery over 20 years in a population sample  

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Introduction Slow heart rate recovery (HRR) from a graded exercise treadmill test (GXT) is a marker of impaired parasympathetic reactivation that is associated with elevated mortality. Our objective was to test whether demographic, behavioral or coronary heart disease (CHD) risk factors during young adulthood were associated with the development of slow HRR. Methods Participants from the Coronary Artery Risk Development in Young Adults study underwent symptom-limited maximal GXT using a modified Balke protocol at baseline (1985–86) and 20-year follow-up (2005–06) examinations. HRR was calculated as the difference between peak heart rate (HR) and HR two-minutes following cessation of the GXT. Slow HRR was defined as 2-minute HRR < 22 beats·min?1. Results In 2,730 participants who did not have slow HRR at baseline, mean HRR was 44 beats*min?1 (SD = 11) at baseline and declined to 40 beats·min?1 (SD=12) in 2005–06; slow HRR developed in 5% (n=135) of the sample by 2005–06. Female sex, black race, fewer years of education, obesity, cigarette smoking, higher depressive symptoms, higher fasting glucose, hypertension, metabolic syndrome and physical inactivity and low fitness were each associated with incident slow HRR. In a multivariable model higher BMI, larger waist, low education, fasting glucose and current smoking remained significantly associated with incident slow HRR. Increasing BMI (per SD higher) over follow-up and incident hypertension, diabetes and metabolic syndrome (in the subsets of participants who were free from those conditions at baseline), were each associated with a significantly elevated odds of incident slow HRR. Conclusions On average, HRR declines with aging; however, the odds of having slow HRR in early middle age is significantly associated with traditional CHD risk factors. PMID:21796053

Carnethon, Mercedes R.; Sternfeld, Barbara; Liu, Kiang; Jacobs, David R.; Schreiner, Pamela J.; Williams, O. Dale; Lewis, Cora E.; Sidney, Stephen

2013-01-01

322

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

323

Diagnostic performance of dual-source CT coronary angiography with and without heart rate control: Systematic review and meta-analysis  

International Nuclear Information System (INIS)

Aim: To investigate the diagnostic accuracy of dual-source computed tomography (DSCT) coronary angiography with and without the application of a ?-blocker. Materials and methods: An exact binomial rendition of the bivariate mixed-effects regression model was used to synthesize diagnostic test data. Results: The pooled sensitivity at the patient level was 0.98 [95% confidence intervals (CI): 0.97–0.99], and specificity 0.88 (95% CI: 0.84–0.91). The results showed that without heart rate control, the sensitivity and specificity at the patient level did not decrease (p = 0.27 and 0.56, respectively). At the artery level, no significant differences in sensitivity and specificity for studies with and without heart rate control were detected (p = 0.04 and 0.05, respectively). At the segment level, the specificity decreased without heart rate control (p = 0.03), whereas the sensitivity was not influenced (p = 0.63). The median radiation exposure was 2.6 mSv, with 1.6 mSv and 8 mSv for heart rate-controlled studies and uncontrolled studies, respectively. Conclusions: DSCT coronary angiography without heart rate control has a similar excellent diagnostic performance at the patient level as that of heart rate control groups. However, controlling for heart rate to decrease radiation and to provide effective information for selecting the therapeutic strategy and risk stratification is recommended

324

The Relationship Between Daytime, Nighttime and 24-Hour Heart Rate with Urinary Albumin and Protein Excretion in Patients with Newly Diagnosed Type 2 Diabetes  

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Full Text Available OBJECTIVE: Autonomic nervous system dysfunction (ASD has been widely observed in patients with type 2 diabetes. 24-hour ambulatory blood pressure (ABP and heart rate measurements have been found to associate with ASD in patient with Type 2 diabetes. Since albumin excretion is also related with ASD in type 2 diabetes; in the current study, the relationships between daytime, nighttime and 24- hour heart rates with 24 hour urinary albumin excretion (UAE and 24-hour urinary protein excretion (UPE were analyzed in patients with newly diagnosed type 2 diabetes. MATERIAL and METHODS: All patients underwent following procedures: history taking, physical examination, BP measurement, 12 lead electrocardiographic evaluations, routine urine analysis, biochemical analysis, 24-hour urine collection to measure UAE, UPE and creatinine clearance. 24-hour ABP and heart rate monitoring were performed for all patients. RESULTS: In total 80 patients with newly diagnosed type 2 diabetes were included. Stepwise linear regression revealed that logarithmically converted 24-hour UAE were independently related with 24- hour ambulatory SBP, (P:0.001 and heart rate (night (P<0.0001. Stepwise linear regression revealed that logarithmically converted 24-hour UPE were independently related with age (P:0.032, with averaged fasting blood glucose (P:0.023, with 24-hour ambulatory SBP, (P:0.002 and with heart rate (night (P:0.001. CONCLUSION: Nighttime heart rate, but not daytime and 24-hour heart rate was related with both 24-hour UAE and UPE in patients with Type 2 diabetes.

Bar?? AF?AR

2012-05-01

325

Spectral analysis of time series of events: effect of respiration on heart rate in neonates  

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Certain types of biomedical processes such as the heart rate generator can be considered as signals that are sampled by the occurring events, i.e. QRS complexes. This sampling property generates problems for the evaluation of spectral parameters of such signals. First, the irregular occurrence of heart beats creates an unevenly sampled data set which must either be pre-processed (e.g. by using trace binning or interpolation) prior to spectral analysis, or analyzed with specialized methods (e.g. Lomb's algorithm). Second, the average occurrence of events determines the Nyquist limit for the sampled time series. Here we evaluate different types of spectral analysis of recordings of neonatal heart rate. Coupling between respiration and heart rate and the detection of heart rate itself are emphasized. We examine both standard and data adaptive frequency bands of heart rate signals generated by models of coupled oscillators and recorded data sets from neonates. We find that an important spectral artifact occurs due to a mirror effect around the Nyquist limit of half the average heart rate. Further we conclude that the presence of respiratory coupling can only be detected under low noise conditions and if a data-adaptive respiratory band is used

326

Electrolyte and pH dependence of heart rate during hemodialysis: a computer model analysis.  

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The influence of hemodialysis-induced modifications in extracellular fluid characteristics on heart rate was investigated by using a detailed computer model of sinus-node electrical activity. Changes similar to those occurring in the course of hemodialysis in extracellular concentrations of sodium (from 138 to 140 mM), potassium (from 6 to 3.3 mM), and calcium (from 1.2 to 1.5 mM) ions as well as in pH (from 7.31 to 7.4) and intracellular volume were simulated. The model predicted that such changes may largely influence the rhythm of the sinoatrial node pacemaker, causing the heart rate to range from 69 to 86 bpm. Heart rate increases after removing potassium (up to 7 bpm) and also after calcium perfusion (up to 11 bpm) whereas restoring pH slows heart beat (up to 6 bpm). Extracellular sodium has no significant influence, but the heart rate strictly depends on intracellular sodium concentration (5 bpm/mM). A complex dependence of heart rate on electrolytes and pH was also recognized. Providing extracellular potassium concentration is maintained above 5 mM, heart rate exhibits low sensitivity to changes in calcium and potassium. When potassium concentration is reduced below 4.5 mM, heart rate sensitivity to calcium and potassium increases significantly to 10 and 30 bpm/mM, respectively. A sustained increase in heart rate always corresponds to an increase in intracellular sodium concentration. PMID:10816197

Severi, S; Cavalcanti, S

2000-04-01

327

The role of ?7 nicotinic acetylcholine receptor in modulation of heart rate dynamics in endotoxemic rats.  

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Previous reports have indicated that artificial stimulation of the vagus nerve reduces systemic inflammation in experimental models of sepsis. This phenomenon is a part of a broader cholinergic anti-inflammatory pathway which activates the vagus nerve to modulate inflammation through activation of alpha7 nicotinic acetylcholine receptors (?7nACHR). Heart rate variability represents the complex interplay between autonomic nervous system and cardiac pacemaker cells. Reduced heart rate variability and increased cardiac cycle regularity is a hallmark of clinical conditions that are associated with systemic inflammation (e.g. endotoxemia and sepsis). The present study was aimed to assess the role of ?7nACHR in modulation of heart rate dynamics during systemic inflammation. Systemic inflammation was induced by injection of endotoxin (lipopolysaccharide) in rats. Electrocardiogram and body temperature were recorded in conscious animals using a telemetric system. Linear and non-linear indices of heart rate variability (e.g. sample entropy and fractal-like temporal structure) were assessed. RT-PCR and immunohistochemistry studies showed that ?7nACHR is expressed in rat atrium and is mainly localized at the endothelial layer. Systemic administration of an ?7nACHR antagonist (methyllycaconitine) did not show a significant effect on body temperature or heart rate dynamics in naïve rats. However, ?7nACHR blockade could further reduce heart rate variability and elicit a febrile response in endotoxemic rats. Pre-treatment of endotoxemic animals with an ?7nACHR agonist (PHA-543613) was unable to modulate heart rate dynamics in endotoxemic rats but could prevent the effect of endotoxin on body temperature within 24 h experiment. Neither methyllycaconitine nor PHA-543613 could affect cardiac beating variability of isolated perfused hearts taken from control or endotoxemic rats. Based on our observations we suggest a tonic role for nicotinic acetylcholine receptors in modulation of heart rate dynamics during systemic inflammation. PMID:24340009

Mazloom, Roham; Eftekhari, Golnar; Rahimi, Maryam; Khori, Vahid; Hajizadeh, Sohrab; Dehpour, Ahmad R; Mani, Ali R

2013-01-01

328

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

329

Time and frequency domain analysis of heart rate variability in cattle affected by bovine spongiform encephalopathy  

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Full Text Available Abstract Background Heart rate variability (HRV analysis is a method to assess the function of the autonomic nervous system. Brainstem nuclei that influence HRV are affected by vacuolar changes and accumulation of disease-associated prion protein (PrPd in bovine spongiform encephalopathy (BSE resulting in clinical signs suggestive of an increased parasympathetic tone. It was hypothesised that BSE in cattle causes changes in the autonomic nervous system; this was tested by comparing HRV indices derived from 1048 electrocardiograms, which were recorded from 51 naturally or experimentally infected cattle with BSE confirmed by postmortem tests, 321 clinical suspect cases or cattle inoculated with potentially infectious tissue without disease confirmation and 78 BSE-free control cattle. Findings Statistically significant differences were found for low or high frequency power, their normalised values and ratio when the last recording prior to cull or repeated recordings were compared but only between male and female cattle of the three groups and not between groups of the same gender, even though BSE cases of each gender appeared to be more nervous during the recording. The same findings were made for heart rate, deviation from the mean RR interval and vasovagal tonus index when repeated recordings were compared. BSE cases with severe vacuolar changes in the parasympathetic nucleus of the vagus nerve had a significantly lower low:high frequency power ratio but not a lower heart rate than BSE cases with mild vacuolation, whereas severity of vacuolar changes in the solitary tract nucleus or intensity of PrPd accumulation in both nuclei did not appear to have any affect on either index. Abnormalities in the electrocardiogram were detected in 3% of the recordings irrespective of the BSE status; sinus arrhythmia was present in 93% of the remaining recordings. Conclusions HRV analysis was not useful to distinguish BSE-positive from BSE-negative cattle grouped by gender, and HRV indices appeared to be mainly influenced by gender. There is agreement with earlier studies that vacuolar changes in the brainstem may be associated with an increased parasympathetic tone in BSE and that abnormalities in an electrocardiogram can be detected in cattle without evidence of heart disease.

Konold Timm

2011-07-01

330

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.

2012-04-01

331

Effects of heart rate on myocardial thallium-201 uptake and clearance  

International Nuclear Information System (INIS)

The effects of heart rate on the myocardial uptake and clearance of 201Tl were studied prospectively in seven healthy men, mean age 43 +/- 7 (s.d.) yr. Initial and delayed (3 hr) thallium images were obtained in three views after three bicycle exercise tests: to maximal, 80% and 60% of predicted maximal heart rate. The mean of three views initial myocardial 201Tl uptake was higher at maximal than at both 80% and 60% of predicted maximal heart rate, being 81% (p less than 0.01) and 60% (p less than 0.01) of maximal activity, respectively. The myocardial activity in the delayed images was identical. There was a linear relationship between heart rate and the initial myocardial activity, r = 0.86 (p less than 0.001). The mean (range) 201Tl clearance was 58% (51-65), 47% (34-56), and 34% (22-49) (all differences p less than 0.01), respectively. Concordance among the three individual views in estimating clearance was best for the highest exercise level. There was a linear relationship between heart rate and clearance, r = 0.80 (p less than 0.001). Clearance was altered by only 1.67 x 10%/heart bpm (0.024 hr/heart beat). Clearance in the liver, spleen and lungs increased at submaximal exercise levels. Thus, a linear relationship between heart rate and clearance is the result of changes in the initial exercise myocardial 201Tl activity. Submaximal exercise may reduce reproducibility of clearance estimation, and the change of myocardial clearance with heart rate seems less than previously suggested

332

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. PMID:24926120

Kang, Jong Ho; Hyong, In Hyouk

2014-01-01

333

Atrial fibrillation detection by heart rate variability in Poincare plot  

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Abstract Background Atrial fibrillation (AFib) is one of the prominent causes of stroke, and its risk increases with age. We need to detect AFib correctly as early as possible to avoid medical disaster because it is likely to proceed into a more serious form in short time. If we can make a portable AFib monitoring system, it will be helpful to many old people because we cannot predict when a patient will have a spasm of AFib. Methods We analyzed heart beat varia...

Jeon Moongu; Lee Sangwook; Park Jinho

2009-01-01

334

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

335

Accuracy of pulse oximeters in estimating heart rate at rest and during exercise.  

Science.gov (United States)

Pulse oximeters are being widely used for non-invasive, simultaneous assessment of haemoglobin oxygen saturation. They are reliable, accurate, relatively inexpensive and portable. Pulse oximeters are often used for estimating heart rate at rest and during exercise. However, at present the data available to validate their use as heart rate monitors are not sufficient. We evaluated the accuracy of two oximeters (Radiometer, ear and finger probe; Ohmeda 3700, ear probe) in monitoring heart rate during incremental exercise by comparing the pulse oximeters with simultaneous ECG readings. Data were collected on eight men (713 heart rate readings) during graded cycle ergometer and treadmill exercise to volitional fatigue. Analysis by linear regression revealed that general oximeter readings significantly correlated with those of ECG (r = 0.91, P less than 0.0001). However, comparison of heart rate at each level of work showed that oximeter readings significantly (P less than 0.05) under-estimated rates above 155 beats/min. These results indicate that the use of pulse oximeters as heart rate monitors during strenuous exercise is questionable. This inaccuracy may well originate from the instability of the probes, sweating, other artefacts during exercise, and measurement of different components in the cardiovascular cycle. PMID:1777787

Iyriboz, Y; Powers, S; Morrow, J; Ayers, D; Landry, G

1991-09-01

336

Exercise-induced improvements in cardiorespiratory fitness and heart rate response to exercise are impaired in overweight/obese postmenopausal women  

Directory of Open Access Journals (Sweden)

Full Text Available OBJECTIVE: The purpose of this study was to compare the heart rate response to exercise and the exercise-induced improvements in muscle strength, cardiorespiratory fitness and heart rate response between normal-weight and overweight/obese postmenopausal women. METHODS: Sedentary women (n = 155 were divided into normal-weight (n = 79; BMI 25 kg/m²; 58.3 + 8.6 years groups, and have their 1-repetition maximum strength (adjusted for body mass, cardiorespiratory fitness and heart rate response to a graded exercise test compared before and after 12 months of a three times-per-week exercise-training program. RESULTS: Overweight/obese women displayed decreased upper and lower extremity muscle strengths, decreased cardiorespiratory fitness, and lower peak and reserve heart rates compared to normal-weight women. After follow-up, both groups improved their upper (32.9% and 41.5% in normal-weight and overweight/obese women, respectively and lower extremity(49.5% and 47.8% in normal-weight and overweight/obese women, respectively muscle strength. However, only normal-weight women improved their cardiorespiratory fitness (6.6% and recovery heart rate (5 bpm. Resting, reserve and peak heart rates did not change in either group. CONCLUSIONS: Overweight/obese women displayed impaired heart rate response to exercise. Both groups improved muscle strength, but only normal-weight women improved cardiorespiratory fitness and heart rate response to exercise. These results suggest that exercise-induced improvements in cardiorespiratory fitness and heart rate response to exercise may be impaired in overweight/obese postmenopausal women.

Emmanuel Gomes Ciolac

2011-01-01

337

New Insights into the Relationship Between Poincare Plot Geometry and Linear Measures of Heart Rate Variability.  

Science.gov (United States)

The Poincare plot is an emerging Heart Rate Variability (HRV) analysis technique, the geometry of which has been shown to distinguish between healthy and unhealthy subjects in clinical settings. The Poincare plot is able to display nonlinear aspects of th...

M. Brennan, M. Palaniswami, P. Kamen

2001-01-01

338

Age related reference ranges of heart rate for Saudi children and adolescents.  

Directory of Open Access Journals (Sweden)

The present study provides age-specific reference values for heart rate (HR of Saudi children and adolescents based on a large study sample. The use of these standards should aid the identification of children with abnormal HR.

Mansour M. Al-Qurashi

2009-07-01

339

Anticipatory Heart Rate Deceleration and Reaction Time in Children with and without Referral for Learning Disability  

Science.gov (United States)

The finding of major significance in this study concerns the effect of stimulant drug medication on the relationship between heart rate deceleration and reaction time with the clinic children. (Authors)

Sroufe, L. Alan; And Others

1973-01-01

340

Facial electromyogram and heart-rate correlates of a paradoxical attitude change to antinuclear war information  

International Nuclear Information System (INIS)

The effects of film images versus film descriptions of the effects of nuclear explosions (versus a no-film control) on corrugator muscle tension, heart rate, attitude and mood were investigated. The last 5 min. of the images were associated with more corrugator tension for that condition when compared to the last 5 min. of the description condition. The groups did not differ in heart rate but women in both groups showed an increase in heart rate whereas men in both groups showed a decrease in heart rate. Film groups did not differ in their significant increases in anxiety, hostility, and depression on the Multiple Adjective Affect Checklist. On the pretest there was no significant correlation between scores on Betts' Questionnaire Upon Mental Imagery and scores on Goldenring and Doctor's index of concern for nuclear war. The vivid-image film group showed a decrease in concern for nuclear war when compared to the descriptive film group and the no-film control

 
 
 
 
341

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)

342

Using complexity metrics with R-R intervals and BPM heart rate measures.  

Science.gov (United States)

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-min (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 non-linear analyses, the success of non-linear 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 non-linear aspects of heart beat dynamics. PMID:23964244

Wallot, Sebastian; Fusaroli, Riccardo; Tylén, Kristian; Jegindø, Else-Marie

2013-01-01

343

Evaluation of the effects of duloxetine and escitalopram on 24-hour heart rate variability: a mechanistic study using heart rate variability as a pharmacodynamic measure.  

Science.gov (United States)

A decrease in heart rate variability (HRV) can indicate increased sympathetic nervous system activity and possibly increased norepinephrine levels. In this randomized, placebo- and escitalopram (ESC)-controlled, subject-blind, 2-period, crossover study, 26 healthy subjects 50 to 65 years old received duloxetine (DLX) 60 mg once daily or ESC 20 mg once daily for 11 days, each in sequential study periods separated by a 10-day or more washout period. Continuous electrocardiogram recordings were obtained by Holter monitoring (baseline, day 9, and day 10 of treatment). Duloxetine and ESC did not produce any clinically significant effects on standard measures of HRV, which included SD of normal R-R intervals and the root mean square difference among successive R-R normal intervals index values, mean change in SD of normal R-R intervals, and frequency domain analysis. However, treatment with DLX was associated with significantly less change from baseline in total beats per 24 hours than ESC, which was an unexpected finding compared with previous observations in which vital signs were measured at a specific time point while awake. In conclusion, in healthy adults exposed to DLX or ESC, no clinically significant effects on HRV were observed. PMID:23422380

Chappell, Jill C; Kovacs, Richard; Haber, Harry; Wright, Ryan; Mitchell, Malcolm I; Detke, Michael; Pangallo, Beth

2013-04-01

344

New Cardiovascular Risk Factors; Resting Heart Rate, Hs-CRP, Fibrinogen and PMNL  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Aim: In this study we aimed to evaluate the possibility of a presence of an association between the high resting heart rate and micro inflammatory response and with the help of any found, clarify the recently identified negative cardiovascular prognosis in individuals with high resting heart rate from an etiological point of view. Material and Method: Study was conducted in September, 2009 with a total of 67 male cases consisting of 36 cases that are followed up at Haseki Egt. ve Ars. Hospita...

Mehmet Aktu?lu; Abdülbaki Kumbasar; Hülya Çilingir; Mehmet Beliba?l?

2012-01-01

345

Breakdown of Long-Range Correlations in Heart Rate Fluctuations During Meditation  

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The average wavelet coefficient method is applied to investigate the scaling features of heart rate variability during meditation, a state of induced mental relaxation. While periodicity dominates the behavior of the heart rate time series at short intervals, the meditation induced correlations in the signal become significantly weaker at longer time scales. Further study of these correlations by means of an entropy analysis in the natural time domain reveals that the induce...

Papasimakis, Nikitas; Pallikari, Fotini

2009-01-01

346

Chaotic Behavior of Heart Rate Signals during Chi and Kundalini Meditation  

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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 th...

Atefeh Goshvarpour; Ateke Goshvarpour

2012-01-01

347

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

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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

348

Learned Cardiac Control with Heart Rate Biofeedback Transfers to Emotional Reactions  

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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, Mats

2013-01-01

349

Patterns of physical activity determined by heart rate monitoring among diabetic children  

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Background: Children with type 1 diabetes should be encouraged to participate in physical activity because exercise can benefit insulin sensitivity and improve known risk factors for atherosclerosis. Methods: Physical activity patterns of 127 children and adolescents with stable type 1 diabetes were investigated by 24 hour continuous heart rate monitoring. The percentage of heart rate reserve was used to measure the amounts of physical activity at different intensities. The results were compa...

Massin, M. M.; Lebrethon, M. C.; Brumioul, Danielle; Ge?rard, Paul; Bourguignon, Jean-pierre

2005-01-01

350

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

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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

351

Time-Frequency Analysis of Heart Rate Variability for Neonatal Seizure Detection  

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There are a number of automatic techniques available for detecting epileptic seizures using solely electroencephalogram (EEG), which has been the primary diagnosis tool in newborns. The electrocardiogram (ECG) has been much neglected in automatic seizure detection. Changes in heart rate and ECG rhythm were previously linked to seizure in case of adult humans and animals. However, little is known about heart rate variability (HRV) changes in human neonate during seizure. In this paper,...

Boualem Boashash; Malarvili, M. B.; Mostefa Mesbah

2007-01-01

352

Blood pressure and heart rate variability and baroreflex sensitivity before and after brain death  

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OBJECTIVES—To evaluate spontaneous blood pressure and heart rate variability and spontaneous baroreflex sensitivity before and after brain death.?METHODS—Spontaneous variability of arterial blood pressure and heart rate—estimated by power spectra of systolic (SBP) and diastolic blood pressure (DBP) and pulse interval (PI)—and spontaneous baroreflex sensitivity (BRS)—estimated by the alpha index and the sequence technique—were evaluated in 11 patients twice: ...

Conci, F.; Di, R.; Castiglioni, P.

2001-01-01

353

Myocardial first-pass perfusion: influence of spatial resolution and heart rate on the dark rim artifact.  

Science.gov (United States)

Myocardial perfusion images can be affected by the dark rim artifact. This study aimed to evaluate the effects of the spatial resolution and heart rate on the transmural extent of the artifact. Six pigs under anesthesia were scanned at 1.5T using an echo-planar imaging/fast gradient echo sequence with a nonselective saturation preparation pulse. Three short-axis slices were acquired every heart beat during the first pass of a contrast agent bolus. Two different in-plane spatial resolutions (2.65 and 3.75 mm) and two different heart rates (normal and tachycardia) were used, generating a set of four perfusion scans. The percentage drop of signal in the subendocardium compared to the epicardium and the transmural extent of the artifact were extracted. Additionally, the signal-to-noise and the contrast-to-noise ratios were evaluated. The signal drop as well as the width of the dark rim artifact increased with decreased spatial resolution and with increased heart rates. No significant slice-to-slice variability was detected for signal drop and width of the rim within the four considered groups. signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) ratios decreased with increasing spatial resolution. In conclusion, low spatial and temporal resolution could be correlated with increased extent of the dark-rim artifact and with lower SNR and CNR. PMID:21702061

Meloni, Antonella; Al-Saadi, Nidal; Torheim, Geir; Hoebel, Nadja; Reynolds, H Glenn; De Marchi, Daniele; Positano, Vincenzo; Burchielli, Silvia; Lombardi, Massimo

2011-12-01

354

The effect of programmed exercise on body compositions and heart rate of 11-13 years-old male students  

Directory of Open Access Journals (Sweden)

Full Text Available Background: Different forms of physical activities can play a very important role in improving health and physical fitness. The purpose of this study was to examine the effect of the programmed exercise on students’ body compositions and heart rate at rest.Materials and Method: Two groups each consisting of 15students, aged averagely 12.6 years were the subjects of this experimental study. The experimental group in each session took part in an exercise program consisting of 20 minutes of aerobic activity (running, 10 minutes of aerobic exercise, 30 minutes of local training and 5 minutes of free exercise. The experiment last for 24 sessions. Control group didn’t do any special practice. In both groups, weight, fat mass, fat percentage, lean body mass and heart rate were measured during rest period before and after the experiment. Results: Results showed that the fat percentage, weight, fat mass and heart rate had decreased after 8 weeks of programmed exercise in the experimental group unlike the control group. However, no significant difference was observed in lean body mass.Conclusion: The exercise program used in this study may help loosing weight and make the heart stronger

Mohammad H. Dashti

2011-11-01

355

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

356

Considerations in the assessment of heart rate variability in biobehavioral research  

Directory of Open Access Journals (Sweden)

Full Text Available Heart rate variability (HRV refers to various methods of assessing the beat-to-beat variation in the heart over time, in order to draw inference on the outflow of the autonomic nervous system. Easy access to measuring HRV has led to a plethora of studies within emotion science and psychology assessing autonomic regulation, but significant caveats exist due to the complicated nature of HRV. Firstly, both breathing and blood pressure regulation have their own relationship to social, emotional and cognitive experiments – if this is the case are we observing heart rate changes as a consequence of breathing changes? Secondly, experiments often have poor internal and external controls. In this review we highlight the interrelationships between heart rate and respiration, as well as presenting recommendations for researchers to use when collecting data for HRV assessment. Namely, we highlight the superior utility of within-subjects designs along with the importance of establishing an appropriate baseline and monitoring respiration.

DanielSQuintana

2014-07-01

357

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

358

Unconstrained monitoring of long-term heart and breath rates during sleep  

International Nuclear Information System (INIS)

An unconstrained method for the long-term monitoring of heart and breath rates during sleep is proposed. The system includes a sensor unit and a web-based network module. The sensor unit is set beneath a pillow to pick up the pressure variations from the head induced by inhalation/exhalation movements and heart pulsation during sleep. The measured pressure signal was digitized and transferred to a remote database server via the network module. A wavelet-based algorithm was employed to detect the heart and breath rates, as well as body movement, during sleep. The overall system was utilized for a total six-month trial operation delivered to a female subject. The profiles of the heart and breath rates on a beat-by-beat and daily basis were obtained. Movements during sleep were also estimated. The results show that the daily average percentage of undetectable periods (UPs) during 881.6 sleep hours over a 180 day period was 17.2%. A total of 89.2% of sleep hours had a UP of not more than 25%. The profile of the heart rate revealed a periodic property that corresponded to the female monthly menstrual cycle. Our system shows promise as a long-term unconstrained monitor for heart and breath rates, and for other physiological parameters related to the quality of sleep and the regularity of the menstrual cycle. (note)

359

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

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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 ...

Stypmann Jörg; Dziewas Rainer; Heuschmann Peter U; Rohde Anne; Ritter Martin A; Nabavi Darius G; Ringelstein Bernd E

2011-01-01

360

The tell-tale heart: heart rate fluctuations index objective and subjective events during a game of chess  

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During a decision-making process, the body changes. These somatic changes have been related to specific cognitive events and also have been postulated to assist decision-making indexing possible outcomes of different options. We used chess to analyze heart rate (HR) modulations on specific cognitive events. In a chess game, players have a limited time-budget to make about 40 moves (decisions) that can be objectively evaluated and retrospectively assigned to specific subjectively perceived eve...

Leone, Mari?a J.; Petroni, Agusti?n; Fernandez Slezak, Diego; Sigman, Mariano

2012-01-01

 
 
 
 
361

Physiological and performance adaptations to an in-season soccer camp in the heat: associations with heart rate and heart rate variability.  

Science.gov (United States)

The aim of the present study was to examine the associations between adaptive responses to an in-season soccer training camp in the heat and changes in submaximal exercising heart rate (HRex, 5-min run at 9 ?km/h), postexercise HR recovery (HRR) and HR variability (HRV). Fifteen well-trained but non-heat-acclimatized male adult players performed a training week in Qatar (34.6?±?1.9°C wet bulb globe temperature). HRex, HRR, HRV (i.e. the standard deviation of instantaneous beat-to-beat R-R interval variability measured from Poincaré plots SD1, a vagal-related index), creatine kinase (CK) activity, plasma volume (PV) changes, and post-5-min run rate of perceived exertion (RPE) were collected at six occasions in temperate environmental conditions (22°C). Players also performed the yo-yo intermittent recovery test level 1 (Yo-Yo IR1) in the same environmental conditions (22°C), both at the beginning and at the end of the training week. Throughout the intervention, HRex and HRV showed decreasing (P?Yo-Yo IR1 performance increased by 7?±?9% (P?=?0.009), which was correlated with changes in HRex [-0.64 (-0.84; -0.28), P?=?0.01]. In conclusion, we found that an in-season soccer training camp in the heat can significantly improve PV and soccer-specific physical performance; both of which are associated with changes in HRex during a 5-min submaximal run. PMID:22092960

Buchheit, M; Voss, S C; Nybo, L; Mohr, M; Racinais, S

2011-12-01

362

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

363

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

364

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

365

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

366

Chronic intermittent hypoxia-hypercapnia blunts heart rate responses and alters neurotransmission to cardiac vagal neurons.  

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Patients with obstructive sleep apnoea experience chronic intermittent hypoxia-hypercapnia (CIHH) during sleep that elicit sympathetic overactivity and diminished parasympathetic activity to the heart, leading to hypertension and depressed baroreflex sensitivity. The parasympathetic control of heart rate arises from pre-motor cardiac vagal neurons (CVNs) located in nucleus ambiguus (NA) and dorsal motor nucleus of the vagus (DMNX). The mechanisms underlying diminished vagal control of heart rate were investigated by studying the changes in blood pressure, heart rate, and neurotransmission to CVNs evoked by acute hypoxia-hypercapnia (H-H) and CIHH. In vivo telemetry recordings of blood pressure and heart rate were obtained in adult rats during 4 weeks of CIHH exposure. Retrogradely labelled CVNs were identified in an in vitro brainstem slice preparation obtained from adult rats exposed either to air or CIHH for 4 weeks. Postsynaptic inhibitory or excitatory currents were recorded using whole cell voltage clamp techniques. Rats exposed to CIHH had increases in blood pressure, leading to hypertension, and blunted heart rate responses to acute H-H. CIHH induced an increase in GABAergic and glycinergic neurotransmission to CVNs in NA and DMNX, respectively; and a reduction in glutamatergic neurotransmission to CVNs in both nuclei. CIHH blunted the bradycardia evoked by acute H-H and abolished the acute H-H evoked inhibition of GABAergic transmission while enhancing glycinergic neurotransmission to CVNs in NA. These changes with CIHH inhibit CVNs and vagal outflow to the heart, both in acute and chronic exposures to H-H, resulting in diminished levels of cardioprotective parasympathetic activity to the heart as seen in OSA patients. PMID:24835174

Dyavanapalli, Jhansi; Jameson, Heather; Dergacheva, Olga; Jain, Vivek; Alhusayyen, Mona; Mendelowitz, David

2014-07-01

367

Predicting survival in heart failure case and control subjects by use of fully automated methods for deriving nonlinear and conventional indices of heart rate dynamics  

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BACKGROUND: Despite much recent interest in quantification of heart rate variability (HRV), the prognostic value of conventional measures of HRV and of newer indices based on nonlinear dynamics is not universally accepted. METHODS AND RESULTS: We have designed algorithms for analyzing ambulatory ECG recordings and measuring HRV without human intervention, using robust methods for obtaining time-domain measures (mean and SD of heart rate), frequency-domain measures (power in the bands of 0.001 to 0.01 Hz [VLF], 0.01 to 0.15 Hz [LF], and 0.15 to 0.5 Hz [HF] and total spectral power [TP] over all three of these bands), and measures based on nonlinear dynamics (approximate entropy [ApEn], a measure of complexity, and detrended fluctuation analysis [DFA], a measure of long-term correlations). The study population consisted of chronic congestive heart failure (CHF) case patients and sex- and age-matched control subjects in the Framingham Heart Study. After exclusion of technically inadequate studies and those with atrial fibrillation, we used these algorithms to study HRV in 2-hour ambulatory ECG recordings of 69 participants (mean age, 71.7+/-8.1 years). By use of separate Cox proportional-hazards models, the conventional measures SD (P.3), were not. In multivariable models, DFA was of borderline predictive significance (P=.06) after adjustment for the diagnosis of CHF and SD. CONCLUSIONS: These results demonstrate that HRV analysis of ambulatory ECG recordings based on fully automated methods can have prognostic value in a population-based study and that nonlinear HRV indices may contribute prognostic value to complement traditional HRV measures.

Ho, K. K.; Moody, G. B.; Peng, C. K.; Mietus, J. E.; Larson, M. G.; Levy, D.; Goldberger, A. L.

1997-01-01

368

AMBIENT POLLUTION AND HEART RATE VARIABILITY. (R826780)  

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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...

369

Systolic reconstruction in patients with low heart rate using coronary dual-source CT angiography  

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Objectives: The purpose of our study was to determine the relationship between the predictive factors and systolic reconstruction (SR) as an optimal reconstruction window in patients with low heart rate (LHR; less than 65 bpm). Methods: 391 patients (262 male and 129 female, mean age; 67.1 {+-} 10.1 years of age) underwent coronary CTA without the additional administration of a beta-blocker. Affecting factors for SR were analyzed in age, gender, body weight (BW), diabetes mellitus (DM), coronary arterial disease (CAD), ejection fraction (EF), systolic and diastolic body pressure (BP) and heart rate variability (HRV) during coronary CTA. Results: In 29 (7.4%) of the 391 patients, SR was needed, but there was no apparent characteristic difference between the systolic and diastolic reconstruction groups in terms of gender, age, BW, DM, CAD and EF. In a multivariate analysis, the co-existence of DM [P < 0.05; OR, 0.27; 95% CI, 0.092-0.80], diastolic BP [P < 0.01; OR, 0.95; 95% CI, 0.92-0.98] and HRV [P < 0.01; OR, 0.98; 95% CI, 0.96-0.99] were found to be the factors for SR. In gender-related analysis, HRV was an important factor regardless of sex, but co-existence of DM affected especially for female and BP for male. Conclusion: Especially in the patients with LHR who had a medication of DM, high HRV or high BP, SR, in addition to DR, was needed to obtain high-quality coronary CTA images.

Okada, Munemasa, E-mail: radokada@yamaguchi-u.ac.jp [Department of Radiology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505 (Japan); Nakashima, Yoshiteru; Shigemoto, Youko; Matsunaga, Naofumi [Department of Radiology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505 (Japan); Miura, Toshiro; Nao, Tomoko [Department of Cardiology, Yamaguchi University Graduate School of Medicine (Japan); Sano, Yuichi; Narazaki, Akiko [Department of Radiology, Yamaguchi University Hospital (Japan); Kido, Shoji [Computer-aided Diagnosis and Biomedical Imaging Research Biomedical Engineering, Applied Medical Engineering Science Graduate School of Medicine, Yamaguchi University (Japan)

2011-11-15

370

The assessment of cardiac sempathovagal activity by heart rate variability in patients with Rheumatoid Arthritis  

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Full Text Available Objectives: It has been reported that increased sempathic nerve system activity due to infalammatory stress and it cause disturbance of heart rate variability (HRV in rheumatoid arthritis (RA. In this study, it was assessed cardiac sempatovagal activity by noninvasive parameters such as HRV in patients with RA.Materials and methods: 49 patients with RA and age-matched 28 healthy subjects as control group were enrolled to this study. Clinical and laboratory parameters of all subjects were assessed and 24-hour electrocardiographic Holter monitoring were performed to all of them.Results: Minimum, maximum and mean heart rate were significantly higher while mean RR interval were significantly lower in patients with RA when compared with controls. In addition, among time domain HRV parameters, SDNN, SDANN ve triangular index were significantly lower in patients with RA (p<0.05, p<0.01, p<0.01, respectively. In correlation analysis, it was not found a significant association between HRV parameters and age, sex, duration and activity of disease, inflammatory markers, supraventricular or ventricular extrasystole (VES. There were only significant negative associations between VES and pNN50, SDANN and RMSDD. But, there was no independent correlation between these parameters.Conclusion: Non-invasive parameters such as HRV may have a modest role in assessment of cardiovascular risk and prediction of sudden cardiac death risk, in addition to the traditional risk factors, in patients with RA. However, to reach to the more accurate decision, there are need to carry out larger and long term studies which include different patients groups

A. Jale Saraç

2010-12-01

371

Systolic reconstruction in patients with low heart rate using coronary dual-source CT angiography  

International Nuclear Information System (INIS)

Objectives: The purpose of our study was to determine the relationship between the predictive factors and systolic reconstruction (SR) as an optimal reconstruction window in patients with low heart rate (LHR; less than 65 bpm). Methods: 391 patients (262 male and 129 female, mean age; 67.1 ± 10.1 years of age) underwent coronary CTA without the additional administration of a beta-blocker. Affecting factors for SR were analyzed in age, gender, body weight (BW), diabetes mellitus (DM), coronary arterial disease (CAD), ejection fraction (EF), systolic and diastolic body pressure (BP) and heart rate variability (HRV) during coronary CTA. Results: In 29 (7.4%) of the 391 patients, SR was needed, but there was no apparent characteristic difference between the systolic and diastolic reconstruction groups in terms of gender, age, BW, DM, CAD and EF. In a multivariate analysis, the co-existence of DM [P < 0.05; OR, 0.27; 95% CI, 0.092-0.80], diastolic BP [P < 0.01; OR, 0.95; 95% CI, 0.92-0.98] and HRV [P < 0.01; OR, 0.98; 95% CI, 0.96-0.99] were found to be the factors for SR. In gender-related analysis, HRV was an important factor regardless of sex, but co-existence of DM affected especially for female and BP for male. Conclusion: Especially in the patients with LHR who had a medication of DM, high HRV or high BP, SR, in addition to DR, was needed to obtain high-quality coronary CTA images.

372

Heart rate response and parasympathetic modulation during recovery from exercise in boys and men.  

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The purpose of this study was to examine the influence of postexercise parasympathetic modulation, measured by heart rate variability (HRV), on heart rate recovery (HRR) in boys (n = 13, 10.1 ± 0.8 years) and men (n = 13, 23.9 ± 1.5 years) following maximal and submaximal exercise. Subjects completed 10 min of supine rest, followed by graded exercise on a cycle ergometer to maximal effort. On a separate day, subjects exercised at an intensity equivalent to ventilatory threshold. Immediately following both exercise bouts, 1-min HRR was assessed in the supine position. HRV was analyzed under controlled breathing during the final 5 min of rest and recovery in the time and frequency domains and transformed to natural log (ln) values. Boys had a greater 1-min HRR than men following maximal (58 ± 8 vs. 47 ± 11 beats·min(-1)) and submaximal (59 ± 8 vs. 47 ± 15 beats·min(-1)) exercise (p exercise, boys had greater ln root mean square successive differences in R-R intervals (2.52 ± 0.95 ms), ln standard deviation of NN intervals (3.34 ± 0.57 ms), ln high-frequency power (4.32 ± 2.00 ms(2)), and ln low-frequency power (4.98 ± 1.17 ms(2)) than men (1.33 ± 0.37 ms, 2.52 ± 0.24 ms, 1.32 ± 1.06 ms(2) and 2.80 ± 0.74 ms(2), respectively) (p exercise (p > 0.05). In conclusion, it appears that greater parasympathetic modulation accounts for greater HRR following maximal exercise in boys versus men. Although submaximal HRR was greater in boys, parasympathetic responses were similar between groups. PMID:24941106

Guilkey, Justin P; Overstreet, Matthew; Fernhall, Bo; Mahon, Anthony D

2014-08-01