WorldWideScience
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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.

Barbara Z. Tharp

2009-01-01

2

Target Heart Rate Calculator  

Science.gov (United States)

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

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Tachycardia | Fast Heart Rate  

Science.gov (United States)

Tachycardia | Fast Heart Rate Updated:Nov 17,2014 Tachycardia = Too fast A heart rate of more than 100 beats per minute (BPM) ... Atrial or Supraventricular tachycardia (SVT) is a fast heart rate that starts in the upper chambers of the ...

4

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 ...

Mr. Peterson

2011-09-18

5

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 ...

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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 ... Where is it and what is a normal heart rate? The best places to find your pulse are ...

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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.

Ingrid Waldron

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Target Heart Rates  

Science.gov (United States)

... the Online Activity Tracker Employers are increasingly using workplace health screenings Fit-Friendly Worksites Fit-Friendly Worksites Recognition The American Heart Association's Fit-Friendly Worksites Program ...

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Fetal Heart Rate Monitoring during Labor  

Science.gov (United States)

What is fetal heart rate monitoring? Fetal heart rate monitoring is the process of checking the condition of your baby during labor and delivery ... heart rate with special equipment. Why is fetal heart rate monitoring done during labor and delivery? Fetal heart ...

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HCN Channels and Heart Rate  

Directory of Open Access Journals (Sweden)

Full Text Available Hyperpolarization and Cyclic Nucleotide (HCN -gated channels represent the molecular correlates of the “funny” pacemaker current (If, a current activated by hyperpolarization and considered able to influence the sinus node function in generating cardiac impulses. HCN channels are a family of six transmembrane domain, single pore-loop, hyperpolarization activated, non-selective cation channels. This channel family comprises four members: HCN1-4, but there is a general agreement to consider HCN4 as the main isoform able to control heart rate. This review aims to summarize advanced insights into the structure, function and cellular regulation of HCN channels in order to better understand the role of such channels in regulating heart rate and heart function in normal and pathological conditions. Therefore, we evaluated the possible therapeutic application of the selective HCN channels blockers in heart rate control.

Ilaria Dentamaro

2012-04-01

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Heart rate variability and breathing.  

Czech Academy of Sciences Publication Activity Database

Víde? : Verlag der Technischen Universität Graz, 2002 - (Hutten, H.; Krösl, P.), s. 586 - 587 ISBN 3-901351-62-0. [EMBEC'02. Víde? (AT), 04.12.2002-08.12.2002] R&D Projects: GA ?R GA102/00/1262; GA ?R GA102/02/1339 Institutional research plan: CEZ:AV0Z2065902 Keywords : heart rate variability * breathing * circulation control Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

Halámek, Josef; Jurák, Pavel; Kára, T.; Sou?ek, M.; Eisenberger, M.; Nykodým, J.

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Heart rate in professional musicians  

OpenAIRE

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 co...

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

2008-01-01

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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 ...

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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 ...

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A stochastic model for heart rate fluctuations  

OpenAIRE

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

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Effect of oxygen treatment on heart rate after abdominal surgery.  

DEFF Research Database (Denmark)

BACKGROUND: Cardiac complications are common during the postoperative period and may be associated with hypoxemia and tachycardia. Preliminary studies in high-risk patients after operation have shown a possible beneficial effect of oxygen therapy on arterial oxygen saturation and heart rate. METHODS: The authors studied the effect of oxygen therapy on arterial oxygen saturation and heart rate in 100 consecutive unselected patients randomly and double blindly allocated to receive air or oxygen therapy between the first and fourth day after major abdominal surgery. RESULTS: The median arterial oxygen saturation rate increased significantly from 96% to 99% (P < 0.0001) and the heart rate decreased significantly from 85 beats/min to 81 beats/min (P < 0.0001) during oxygen supplementation compared with air administered by a binasal catheter. The greatest decrease in heart rate occurred in patients with the lowest oxygen saturation or the highest heart rate values before oxygen supplementation. Overall, 73% of this unselected group of patients responded with decreased heart rate during supplemental oxygen therapy. No significant differences in changes in heart rate after oxygen supplementation were found between patients with or without an epidural catheter or between the postoperative day studied. CONCLUSION: Postoperative oxygen therapy increased arterial oxygen saturation and decreased heart rate after uncomplicated abdominal surgery in a consecutive unselected group of patients who received routine postoperative care.

Rosenberg-Adamsen, S; Lie, C

1999-01-01

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Heart rate reduction and longevity in mice.  

Science.gov (United States)

Heart rate correlates inversely with life span across all species, including humans. In patients with cardiovascular disease, higher heart rate is associated with increased mortality, and such patients benefit from pharmacological heart rate reduction. However, cause-and-effect relationships between heart rate and longevity, notably in healthy individuals, are not established. We therefore prospectively studied the effects of a life-long pharmacological heart rate reduction on longevity in mice. We hypothesized, that the total number of cardiac cycles is constant, and that a 15% heart rate reduction might translate into a 15% increase in life span. C57BL6/J mice received either placebo or ivabradine at a dose of 50 mg/kg/day in drinking water from 12 weeks to death. Heart rate and body weight were monitored. Autopsy was performed on all non-autolytic cadavers, and parenchymal organs were evaluated macroscopically. Ivabradine reduced heart rate by 14% (median, interquartile range 12-15%) throughout life, and median life span was increased by 6.2% (p = 0.01). Body weight and macroscopic findings were not different between placebo and ivabradine. Life span was not increased to the same extent as heart rate was reduced, but nevertheless significantly prolonged by 6.2%. PMID:25589054

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

2015-03-01

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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

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Volitional control of the heart rate.  

Science.gov (United States)

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

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

2013-11-01

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Metaiodobenzylguanidine and heart rate variability in heart failure  

Energy Technology Data Exchange (ETDEWEB)

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

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

1998-10-01

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Heart rate variations during sleep in preadolescents.  

Science.gov (United States)

Heart rate variations during sleep have been documented for infant and adult populations, but not for children and adolescents. To provide normative data for the preadolescent age group, this investigation used a combination of time-domain measures and nonlinear procedures (Poincare plots) to describe heart rate variations during two consecutive nights of undisturbed baseline sleep in 14 normal 8- to 10-year-old males. Heart rate variables, based on all-night analyses of computer-determined beat-to-beat (RR) intervals, were related to sleep stage and sleep cycle measures within and across nights. Time-domain summary statistics revealed a tendency for higher mean heart rates in rapid eye movement (REM) compared to slow-wave (SW) and stage 2 sleep, but the differences were not significant. Heart rate variability, as measured by average RR interval standard deviation, was greatest in stage 2 and least in SW sleep, but it did not vary significantly across sleep stages. Analyses of heart rate variables across the initial four sleep cycles showed a significant heart rate decrease (quadratic trend) and a significant increase (linear trend) for heart rate variability. All effects replicated across nights. Poincare plots revealed wide-ranging individual differences, generally characterized by greater dispersion at longer RR intervals and a remarkable night-to-night consistency in whole-night as well as stage-specific patterns. The sleep-stage plots uniformly indicated reduced overall range and variability in SW relative to REM and stage 2 and a general equivalence of stage 2 and REM patterns. The results indicate several features of sleep-related heart rate variations in preadolescents that differ from those in adults. The differences can be attributed to developmental variations in autonomic cardiac control and are consistent with increased parasympathetic influences reported to occur at this time. PMID:8855034

Pivik, R T; Busby, K A; Gill, E; Hunter, P; Nevins, R

1996-02-01

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

OpenAIRE

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

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

2002-01-01

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Evaluation of commercially available heart rate monitors.  

OpenAIRE

The accuracy and tracking ability of nine commercially available heart rate monitors were assessed. The heart rate of 16 young healthy men was continuously monitored by a single-lead electrocardiograph while they exercised on a stationary bicycle ergometer. Readings were obtained from the devices during exercise. The devices that measured the cardiac electrical potential with a three-electrode system or that incorporated a light transmission device attached to the earlobe were the most accura...

Humen, D. P.; Boughner, D. R.

1984-01-01

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Heart rate recovery in patients with ischemic heart disease - risk factors  

Directory of Open Access Journals (Sweden)

Full Text Available Background and aim. Central nervous system dysfunction is associated with mortality and morbidity in patients with cardiovascular disease, post-workout recovery and faster heart rate being mediated by the dynamic interaction between the sympathetic nervous system (SNS and the parasympathetic nervous system (PNS, as components of the autonomic nervous system. Heart rate recovery is the decline in heart rate after exercise. The aim of the study was to determine the influence of certain clinical and paraclinical parameters on heart rate recovery after exercise in patients with ischemic heart disease. Methods. The study included 260 patients who were subjected to cardiovascular stress test. The following parameters were measured in each patient: blood pressure and pulse rate prior to exercise, during exercise and at protocol-established time intervals, as well as 1 and 3 minutes after the end of the stress test. Statistical analysis was performed usingMedCalc software version 14.8.1 Results. Elderly patients had slower heart rate recovery at 1 minute after effort. Female patients have recovered significantly better the heart rate, at 1 minute and 3 minutes after effort compared to the males. This difference was maintained in multivariate analysis, independent of age or comorbidities of patients. The presence of ischemic heart disease was the most important factor independently associated with HRR1.Triglyceride values were negatively correlated with both HRR3 and HRR1 and independent of other factors present in the multivariate analysis. Conclusions. Autonomic dysfunction is involved in the development of cardiovascular risk factors like hypertension, diabetes, dyslipidemia and was directly correlated with morbidity and mortality caused by coronary heart disease.

Cosmin Grad

2014-12-01

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Heart rate variability in familial Mediterranean fever.  

Science.gov (United States)

Familial Mediterranean fever (FMF) is a hereditary disease, characterized by recurrent episodes of fever and polyserositis. Heart rate variability (HRV) is a powerful, simple and reliable technique to evaluate autonomic nervous system function. Previous studies of physiologic parameters during tilt-test have suggested that patients with FMF have abnormal cardiovascular reactivity and occult dysautonomia. Prompted by these findings, the present study sought to evaluate HRV in patients with FMF, at rest and in the standing position. The study sample included 34 patients with FMF and 34 sex- and age-matched control subjects. All underwent electrocardiography according to strict criteria. HRV parameters were computed with custom-made software. There was no significant difference in HRV parameters, in either the supine or standing position, between the FMF and control groups. In both groups, the upright position was associated with a significant decrease, when compared with the supine position, in maximal RR interval, minimal RR, average RR, root square of successive differences in RR interval, number of intervals differing by >50 ms from preceding interval (NN50), NN50 divided by total number of intervals (pNN50) and high-frequency components as well as a significant increase in average heart rate, very low frequency or low-frequency components, low-frequency/high-frequency components ratio and total power. In conclusion, patients with FMF who are continuously treated with low-dose colchicine have not developed amyloidosis and have normal HRV parameters in the supine and upright position. Further investigation of occult dysautonomia in FMF is needed. PMID:19882341

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

2011-01-01

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[Is heart rate adequately controlled in chronic systolic heart failure patients in Germany? Results from a nationwide survey (INDICATE)].  

Science.gov (United States)

Background | Elevated resting heart rate is associated with increased morbidity and mortality in patients with chronic systolic heart failure (CHF). Lowering of heart rate improves cardiovascular outcome in these patients. Therefore, heart rate reduction is an important element of therapeutic management and consistently reflected in current European guidelines for heart failure. Methods | The INDICATE study was initiated as a multicenter nationwide cross-sectional survey aiming to analyze the current quality of care in outpatients with CHF (documented left ventricular systolic dysfunction) in Germany. 20 consecutive patients were to be included in the survey from February until June 2012 by 793 cardiologic private practices. Detailed documentation of each patient was performed using a standardized questionnaire. Results | CHF was known for more than 6 months in 88?% of the 15?148 included patients. Mean heart rate in the study population was 73?±?13?min(-1). In 42?% of patients the heart rate was???75?min(-1). 86?% were treated with betablockers. However, higher doses of betablockers were not associated with lower resting heart rate. 27?% of patients remained on heart rates???75?min(-1) although receiving at least 50?% of betablocker target dose. Conclusion | INDICATE reveals a considerable proportion of outpatients with CHF showing an elevated heart rate despite beta blockade - irrespective of applied dose. These results emphasize the importance of optimizing the pharmacological management of resting heart rate according to guidelines in these patients. PMID:25734683

Zugck, C; Martinka, P; Stöckl, G; Tschöpe, C; Störk, S

2015-03-01

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The relationship between phase and heart rate  

International Nuclear Information System (INIS)

The Fourier phase image is used in rest and stress radionuclide angiocardiography to assess the timing of ventricular wall motion in a regional fashion, and areas of high phase are taken to reprensent areas of delayed contraction. However, phase increases with heart rate and this can make interpretation difficult. This study investigates the relationship between phase and heart rate. A heterogenous group of 43 subjects was studied by ECG-gated equilibrium radionuclide angiocardiography, all of the subjects having normal extent of left ventricular wall motion as judged by normal ejection fraction and normal amplitude image. Mean left ventricular phase correlated well with mean time of end systole (r=0.92), but there was no correlation with time of end diastole.Thus phase reflects the time of end systole as a proportion of cycle length and should be linearly related to heart rate provided the duration of systole is unchanged. In 28 normal subjects mean left ventricular phase correlated linearly with resting rate (r=0.91), and when exercised the relationship was maintained up to 90 beats per minute. Above this rate the increases were less marked as the duration of systole shortened. The same was true in 4 subjects paced at different rates. Mean resting heart rate in the normal subjects was 70 beats per minute and correcting phase linearly to rate 70 did not change mean left ventricular phase but did decrease the standard deviation from 18 degree to 12 degree. It is concln 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)

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Wireless monitoring of Heart Rate using Microcontroller  

OpenAIRE

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 diagno...

Prasath, J. S.

2013-01-01

29

Gaussian Mixture Model of Heart Rate Variability  

OpenAIRE

Heart rate variability (HRV) is an important measure of sympathetic and parasympathetic functions of the autonomic nervous system and a key indicator of cardiovascular condition. This paper proposes a novel method to investigate HRV, namely by modelling it as a linear combination of Gaussians. Results show that three Gaussians are enough to describe the stationary statistics of heart variability and to provide a straightforward interpretation of the HRV power spectrum. Comparisons have been m...

Boccignone, Giuseppe

2012-01-01

30

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

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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.

32

A Novel Thermal Measurement for Heart Rate  

Directory of Open Access Journals (Sweden)

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

33

Wireless monitoring of Heart Rate using Microcontroller  

Directory of Open Access Journals (Sweden)

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

J.S. Prasath

2013-02-01

34

[Heart rate modulation in stable ischemic heart disease: what we have learned from the SIGNIFY study?].  

Science.gov (United States)

Elevated heart rate is a marker of cardiovascular risk in patients with stable coronary artery disease. The addition of ivabradine to standard therapy to reduce heart rate did not improve outcomes in the recent SIGNIFY trial. Moreover, a significant interaction between the effect of ivabradine among subgroups with and without angina with a worse outcome in patients in CCS class >II at baseline was detected. The explanation for this surprising finding despite a significant reduction in angina and myocardial revascularization procedures is uncertain. A J-curve for heart rate was not demonstrated. We speculate a significant interference on adverse events (mainly atrial fibrillation and consequently acute coronary syndromes) and on the outcome of unfavorable interactions between ivabradine and diltiazem, verapamil and strong inhibitors of CYP3A4 (4.6% of the total population). Excluding this subgroup, there are no significant changes in outcomes between the two treatment groups (ivabradine and placebo). In conclusion, heart rate is a marker of risk but is not a risk factor and/or a target of therapy in patients with stable coronary artery disease and preserved ventricular systolic function. Standard doses of ivabradine are indicated for treatment of angina as an alternative or in addition to beta-blockers, but should not be administered in association with CYP3A4 inhibitors or heart rate-lowering calcium antagonists. PMID:25837459

Perna, Gian Piero; Battistoni, Ilaria; Angelini, Luca

2015-03-01

35

Fetal heart rate variation with umbilical haematoma.  

OpenAIRE

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

36

Heart Rate Variability and Blood Pressure during Dynamic and Static Exercise at Similar Heart Rate Levels  

OpenAIRE

Aim was to elucidate autonomic responses to dynamic and static (isometric) exercise of the lower limbs eliciting the same moderate heart rate (HR) response. Method: 23 males performed two kinds of voluntary exercise in a supine position at similar heart rates: static exercise (SE) of the lower limbs (static leg press) and dynamic exercise (DE) of the lower limbs (cycling). Subjective effort, systolic (SBP) and diastolic blood pressure (DBP), mean arterial pressure (MAP), rate pressure product...

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

2013-01-01

37

Compressed sampling for heart rate monitoring.  

Science.gov (United States)

For the first time compressed sampling (CS) has been applied to heart rate (HR) measurements. The signals can be reconstructed from samples far below the Nyquist rate with negligible small errors, a sampling reduction of 8 has been demonstrated in the paper. As a result, the bitrate of the CS sampler is half when compared to a normal sampler. A lower bitrate leads to a reduction in power consumption for HR measurement devices. PMID:22795940

Faust, Oliver; Acharya, U Rajendra; Ma, Jianguo; Min, Lim Choo; Tamura, Toshiyo

2012-12-01

38

Influence of sickness condition on diurnal rhythms of heart rate and heart rate variability in cows.  

Science.gov (United States)

Parameters of heart rate variability would explain changes in heart rate during the disease status in cows and to evaluate whether such changes might provide a more sensitive and quantitative indicator of these conditions than crude indices. For this purpose, we recorded electrocardiograms for 24 hr using a Holter-type electrocardiograph and applied power spectral analysis of heart rate variability in both five clinically healthy and four hospitalized cows. The significant findings of the current investigation were that the diurnal variations of autonomic nervous function are abolished in cows that are sick. This abnormal rhythm was induced by predominant parasympathetic inhibition in these cows. Therefore, the heart rate variability may be a useful indicator of sickness condition in cows. PMID:25648088

Yoshida, Masumi; Onda, Ken; Wada, Yasunori; Kuwahara, Masayoshi

2015-04-01

39

[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

40

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.

2003-04-01

41

Passive fetal heart rate monitoring apparatus and method with enhanced fetal heart beat discrimination  

Science.gov (United States)

An apparatus for acquiring signals emitted by a fetus, identifying fetal heart beats and determining a fetal heart rate. Multiple sensor signals are outputted by a passive fetal heart rate monitoring sensor. Multiple parallel nonlinear filters filter these multiple sensor signals to identify fetal heart beats in the signal data. A processor determines a fetal heart rate based on these identified fetal heart beats. The processor includes the use of a figure of merit weighting of heart rate estimates based on the identified heart beats from each filter for each signal. The fetal heart rate thus determined is outputted to a display, storage, or communications channel. A method for enhanced fetal heart beat discrimination includes acquiring signals from a fetus, identifying fetal heart beats from the signals by multiple parallel nonlinear filtering, and determining a fetal heart rate based on the identified fetal heart beats. A figure of merit operation in this method provides for weighting a plurality of fetal heart rate estimates based on the identified fetal heart beats and selecting the highest ranking fetal heart rate estimate.

Zahorian, Stephen A. (Inventor); Livingston, David L. (Inventor); Pretlow, III, Robert A. (Inventor)

1996-01-01

42

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

OpenAIRE

OBJECTIVE--To review the importance of heart rate variability analysis in left ventricular dysfunction and heart failure and to assess the effects of drug treatment. In patients with left ventricular dysfunction or heart failure, a low heart rate variability is a strong predictor of a low probability of survival. Because drug treatment in these patients has rapidly changed over the past two decades, the effect of these drugs on heart rate variability needs special attention. DESIGN--A study o...

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

1994-01-01

43

Fetal heart rate variation with umbilical haematoma.  

Science.gov (United States)

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. Images Figure 2 Figure 3 PMID:4034467

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

1985-01-01

44

Effects of aerobic training on heart rate  

OpenAIRE

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 autorhythmici...

Almeida Marcos B.; Araújo Claudio Gil S.

2003-01-01

45

Quantitative analysis of heart rate variability  

OpenAIRE

In the modern industrialized countries every year several hundred thousands of people die due to the sudden cardiac death. The individual risk for this sudden cardiac death cannot be defined precisely by common available, non-invasive 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 analyse the HRV. Especially, some complexity meas...

Kurths, Ju?rgen; Voss, A.; Witt, Annette; Saparin, P.; Kleiner, H. J.; Wessel, N.

1994-01-01

46

Case Studies in Electronic Fetal Heart Rate Monitoring  

OpenAIRE

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

47

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

48

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

49

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

50

Heart rate recovery after maximal and submaximal exercise  

OpenAIRE

Pasi Karjalainen (2012). Heart rate recovery after maximal and submaximal exercise. Department of Biology of Physical Activity, University of Jyväskylä, Master thesis in exercise physiology, 76 pages. Heart rate recovery (HRR) after exercise reflects autonomic control of the heart. Heart rate recovery (HRR) has shown to have prognostic value among asymptomatic populations and patients with diseases. In addition, changes in HRR may reflect the effects of training load. The role of parasym...

Karjalainen, Pasi

2012-01-01

51

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.

52

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

53

General anesthesia suppresses normal heart rate variability in humans  

Science.gov (United States)

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

Matchett, Gerald; Wood, Philip

2014-06-01

54

Effect of Yoga Therapy on Heart Rate, Blood Pressure and Cardiac Autonomic Function in Heart Failure  

OpenAIRE

Background and Objective: It is well known that a hall mark of heart failure is adverse changes in autonomic function. Elevated blood pressure is a powerful predictor of congestive heart failure and other Cardiovascular Disease (CVD) outcomes. In this study, we planned to examine the effects of a 12 week yoga therapy on blood pressure, heart rate, heart rate variability, and rate pressure product (RPP).

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

2014-01-01

55

Vaginal intercourse frequency and heart rate variability.  

Science.gov (United States)

We examined the relationship between recalled and diary recorded frequency of penile-vaginal intercourse (FSI) and both resting heart rate variability (HRV; an index of cardiac autonomic control and parasympathetic tone associated with cardiovascular health outcomes) and resting diastolic blood pressure (DBP) in 120 healthy adults aged 19-38 (subjects scoring above the 87th percentile on the Lie scale of the Eysenck Personality Inventory were excluded from analyses). As in a previous smaller study, greater HRV was associated with greater FSI (but not masturbation or non-coital sex with a partner) and rated importance of intercourse. There were no sex differences in the HRV-FSI relationship, and the relationship was not explained by including measures of Extraversion, Neuroticism, Depression, Trait Anxiety, or partnership satisfaction. However, the previously obtained negative association of FSI with DBP was not replicated. PMID:14504008

Brody, Stuart; Preut, Ragnar

2003-01-01

56

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

Directory of Open Access Journals (Sweden)

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

57

Influence of semen collection on salivary cortisol release, heart rate, and heart rate variability in stallions.  

Science.gov (United States)

The aim of this study was to evaluate the stress response of stallions (n = 16) aged 3-13 years with previous sexual experience to semen collection by determination of heart rate, heart rate variability, and cortisol in saliva. Recordings were done on two consecutive days. The time intervals from leaving the box until arrival in the collection barn and from first exposure to the teaser mare until ejaculation as well as the number of mounts until ejaculation were neither affected by collection day nor by age, sexual experience (i.e., the number of breeding seasons the stallion experienced), or sexual workload of the stallion (i.e., the mean number of semen collections per week). Heart rate was continuously determined from 30 minutes before to 30 minutes after ejaculation and significantly increased in response to the semen collection procedure (P collection did not have any effects. The heart rate variability variable root mean square of successive RR differences was not affected by semen collection procedures. Cortisol concentration in saliva was determined from 60 minutes before to 120 minutes after ejaculation and did not change significantly. The results indicate that semen collection is perceived as not more than a modest temporary stressor in sexually experienced and well-trained stallions. PMID:23664794

Pasing, Stephanie; von Lewinski, Mareike; Wulf, Manuela; Erber, Regina; Aurich, Christine

2013-08-01

58

Procedural Pain Heart Rate Responses in Massaged Preterm Infants  

OpenAIRE

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

59

Relationship between anxiety, heart rate and efficiency of pistol shooting  

Directory of Open Access Journals (Sweden)

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

60

Elevated resting heart rate is associated with the metabolic syndrome  

Directory of Open Access Journals (Sweden)

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

61

POSTURAL CHANGES IN HEART RATE AND BLOOD PRESSURE WITH AGEING  

Directory of Open Access Journals (Sweden)

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

62

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

Directory of Open Access Journals (Sweden)

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

Stampfer HG

2013-04-01

63

Quantitative analysis of heart rate variability  

Science.gov (United States)

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

64

Global Heart Failure Rates and Erythropoietin  

Directory of Open Access Journals (Sweden)

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

65

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

Directory of Open Access Journals (Sweden)

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

66

Heart rate variability interventions for concussion and rehabilitation  

OpenAIRE

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 ...

RobertLakeConder; AlannaA.Conder

2014-01-01

67

AUTONOMIC CONTROL OF HEART RATE AFTER EXERCISE IN TRAINED WRESTLERS  

OpenAIRE

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

Henri?quez, Carlos F.; Eduardo Báez; Astrid Von Oetinger; Rodrigo Cañas; Rodrigo Ramírez

2013-01-01

68

Abnormal heart rate variability and atrial fibrillation after aortic surgery  

Science.gov (United States)

Introduction Complete denervation of transplanted heart exerts protective effect against postoperative atrial fibrillation; various degrees of autonomic denervation appear also after transection of ascending aorta during surgery for aortic aneurysm. Objective This study aimed to evaluate if the level of cardiac denervation obtained by resection of ascending aorta could exert any effect on postoperative atrial fibrillation incidence. Methods We retrospectively analysed the clinical records of 67 patients submitted to graft replacement of ascending aorta (group A) and 132 with aortic valve replacement (group B); all episodes of postoperative atrial fibrillation occurred during the 1-month follow-up have been reported. Heart Rate Variability parameters were obtained from a 24-h Holter recording; clinical, echocardiographic and treatment data were also evaluated. Results Overall, 45% of patients (group A 43%, group B 46%) presented at least one episode of postoperative atrial fibrillation. Older age (but not gender, abnormal glucose tolerance, ejection fraction, left atrial diameter) was correlated with incidence of postoperative atrial fibrillation. Only among a subgroup of patients with aortic transection and signs of greater autonomic derangement (heart rate variability parameters below the median and mean heart rate over the 75th percentile), possibly indicating more profound autonomic denervation, a lower incidence of postoperative atrial fibrillation was observed (22% vs. 54%). Conclusion Transection of ascending aorta for repair of an aortic aneurysm did not confer any significant protective effect from postoperative atrial fibrillation in comparison to patients with intact ascending aorta. It could be speculated that a limited and heterogeneous cardiac denervation was produced by the intervention, creating an eletrophysiological substrate for the high incidence of postoperative atrial fibrillation observed. PMID:25859868

Compostella, Leonida; Russo, Nicola; D’Onofrio, Augusto; Setzu, Tiziana; Compostella, Caterina; Bottio, Tomaso; Gerosa, Gino; Bellotto, Fabio

2015-01-01

69

The effect of exercise and heart rate on fibrinolytic activity.  

OpenAIRE

The effect of heart rate on plasma fibrinolytic activity was investigated in nine patients with dual chamber cardiac pacemakers before and after 10 min of stimulated tachycardia to 123 beats/min. The results were compared to seven volunteers who performed submaximal exercise to 90% target heart rate and to five of the seven who underwent a second period of exercise to a heart rate of 120 beats/min. During submaximal exercise (mean heart rate 152 beats/min) the median ECLT fell from 248 min (i...

Gough, Sc; Whitworth, S.; Rice, Pj; Grant, Pj

1992-01-01

70

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

Science.gov (United States)

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.

71

Heart Rate and Cardiovascular Disease: An Alternative to Beta Blockers  

OpenAIRE

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

Michael Liang; Aniket Puri; Gerard Devlin

2009-01-01

72

1/f Scaling in Heart Rate Requires Antagonistic Autonomic Control  

OpenAIRE

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

73

Heart Rate Dynamics During A Treadmill Cardiopulmonary Exercise Test in Optimized Beta-Blocked Heart Failure Patients  

OpenAIRE

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; Emmanuel Gomes Ciolac; Edimar Alcides Bocchi

2008-01-01

74

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

OpenAIRE

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

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

2009-01-01

75

Pre-exercise food and heart rate during submaximal exercise.  

OpenAIRE

The heart rates of 20 movement studies students were measured during multi-stage cycle ergometer tests. The tests were repeated on five occasions following the ingestion of different pre-exercise meals and the results compared. A glucose solution taken three hours prior to the exercise (G3) resulted in the lowest heart rates at each work rate. The highest heart rates at each work rate were recorded following the ingestion of glucose or protein one hour before the exercise (G1 and P1 respectiv...

Bird, S. R.; Hay, S.

1987-01-01

76

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

77

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  

OpenAIRE

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

78

Heart Rate Variability: Measures and Models  

OpenAIRE

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...

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

2000-01-01

79

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

Science.gov (United States)

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 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

80

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

81

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

82

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 fcantly 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)

83

Serum AChE Activities Predict Exercise Heart Rate Parameters of Asymptomatic Individuals  

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

Canaani Jonathan

2010-12-01

84

Original paper
Heart rate variability in adult patients with congenital heart disease
 

OpenAIRE

Introduction: Heart rate variability (HRV) illustrates an autonomic nervous system influence on the sinus node. It is known that low HRV parameters indicate poor prognosis in patients with myocardial infarction, predict sudden cardiac death and death due to heart failure. Adult population with congenital heart disease (CongHD) is particularly exposed to these complications. The aim of this study was to evaluate HRV parameters in adult patients with CongHD and to analyse the impact of the spec...

Olga Trojnarska; Piotr Br?borowicz; Magdalena ?anocha; Maciej Lesiak; Wies?aw Bryl; Andrzej Cie?li?ski

2005-01-01

85

Fuzzy Logic System for Fetal Heart Rate Determination  

Directory of Open Access Journals (Sweden)

Full Text Available This paper focuses on the Fuzzy Logic System for fetal heart rate determination. The clinical interpretation of fetal heart rate trace is a difficult task and this has led to the development of computerised systems. These systems are limited by their inability to represent uncertainty. This paper describes the development of a fuzzy expert system for fetal heart rate. The fuzzy logic system improved on the crisp system and has achieved the highest overall performance. With the results obtained, it is evident that the fuzzy logic system can be used to improve the efficiency of the clinician position for making accurate diagnosis.

UDO, E.U.

2015-02-01

86

[Methodology for analysis of binary sequences in heart rate].  

Science.gov (United States)

A qualitative and quantitative method for the description of heart rate variability is demonstrated. It is based on a symbolic coding of time series taken from heartbeat intervals and calculation of the value "entropy" as a measure for information. Entropy seems to be a propriate measure to gain insight into the temporal structure underlying the phenomenon of heart variability. PMID:8588394

Schäfer, C; Plesser, T; Abel, H H

1995-01-01

87

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

88

Parathyroidectomy and Heart Rate Variability in Patients with Stage 5 CKD  

Science.gov (United States)

Summary Background and objectives Lower heart rate variability implies increased risk of cardiovascular disease. This study aimed to evaluate the relationship between mineral metabolism and heart rate variability and longitudinal changes of heart rate variability after parathyroidectomy in stage 5 CKD patients. Design, setting, participants, & measurements This cross-sectional study included 118 stage 5 CKD patients, 87 controls, and a prospective study in two subgroups classified as successful (n=17) and unsuccessful (n=4) parathyroidectomy follow-up enrolled from March of 2011 to December of 2012. Blood examination and 24-hour Holter for heart rate variability were measured. Results Most heart rate variability indices were lower in stage 5 CKD patients. In multivariate stepwise regression models, serum intact parathyroid hormone was correlated with mean normal-to-normal R–R intervals, mean heart rate, and very low frequency, serum calcium was correlated with SD of 5-minute average of normal R–R intervals, and serum phosphorus was correlated with very low frequency and low frequency/high frequency. Compared with baseline, the successful parathyroidectomy subgroup had significant improvements in mean normal-to-normal R–R intervals, mean heart rate, SD of normal-to-normal R–R intervals, SD of 5-minute average of normal R–R intervals, very low frequency, high frequency, and low frequency/high frequency. There was no significant change of heart rate variability in patients after unsuccessful parathyroidectomy. Conclusions Disorders of mineral metabolism are associated with decreased heart rate variability in stage 5 CKD. Successful parathyroidectomy may contribute to reverse this cardiovascular disease risk in severe secondary hyperparathyroidism patients. PMID:23660181

Zhang, Jing; Yu, Xiangbao; Sun, Bin; Bai, Jianling; Wei, Yongyue; Zha, Xiaoming; Cui, Yiyao; Zeng, Ming; Zhang, Jingjing; Liu, Jia; Mao, Huijuan; Zhang, Bo; Ren, Haibin; Ge, Yifei; Xu, Xueqiang; Shen, Zhixiang; Xing, Changying; Cao, Kejiang

2013-01-01

89

Design and Development of a Heart Rate Measuring Device using Fingertip  

OpenAIRE

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

90

Heart rate and salivary cortisol concentrations in foals at birth.  

Science.gov (United States)

Heart rate (HR), HR variability (HRV) and salivary cortisol concentrations were determined in foals (n?=?13) during the perinatal phase and until 5 months of age. In the fetus, HR decreased from 77?±?3 beats/min at 120?min before birth to 60?±?1 beats/min at 5?min before birth (P?beats/min (P?<0.01). Salivary cortisol concentrations immediately after birth were 11.9?±?3.6?ng/mL and within 2?h increased to a maximum of 52.5?±?12.3?ng/mL (P?<0.01). In conclusion, increases in HR and salivary cortisol concentrations in foals are not induced during parturition, but occur immediately after birth. PMID:25582796

Nagel, C; Erber, R; Ille, N; Wulf, M; Aurich, J; Möstl, E; Aurich, C

2015-02-01

91

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

OpenAIRE

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

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

1985-01-01

92

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

OpenAIRE

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

93

Time- and state-dependent analysis of autonomic control in narcolepsy: higher heart rate with normal heart rate variability independent of sleep fragmentation.  

Science.gov (United States)

Narcolepsy with hypocretin deficiency is known to alter cardiovascular control during sleep, but its aetiology is disputed. As cardiovascular control differs between sleep states, and narcolepsy affects sleep architecture, controlling for both duration and transitions of sleep states is necessary. This study therefore aimed to assess heart rate and its variability in narcolepsy during sleep taking these factors into account. The study included 12 medication-naïve patients with narcolepsy with cataplexy and hypocretin deficiency (11 male, 16-53 years old), and 12 sex- and age-matched healthy controls (11 male, 19-55 years). All subjects underwent 1-night ambulatory polysomnography recording. Cardiovascular parameters were calculated for each 30-s epoch. Heart rate was significantly higher in patients with narcolepsy than in controls in all sleep states and during wakefulness prior to sleep. Groups did not differ in heart rate variability measures. The effects of sleep state duration on heart rate and its variability were similar between patients and controls. In conclusion, heart rate was consistently higher in patients with narcolepsy than controls, independent of sleep stage and sleep fragmentation. A direct effect of hypocretin deficiency therefore seems probable. PMID:25382307

van der Meijden, Wisse P; Fronczek, Rolf; Reijntjes, Robert H A M; Corssmit, Eleonora P M; Biermasz, Nienke R; Lammers, Gert Jan; van Dijk, J Gert; Thijs, Roland D

2015-04-01

94

Heart rate, ischaemic heart disease, and sudden cardiac death in middle-aged British men.  

OpenAIRE

OBJECTIVE--To examine the relation between resting heart rate and new major ischaemic heart disease events in middle aged men with and without pre-existing ischaemic heart disease. DESIGN--Prospective study of a cohort of men with eight years follow up for cardiovascular morbidity and mortality for all men. SETTING--General practices in 24 British towns (the British Regional Heart study). SUBJECTS--7735 men aged 40-59 years drawn at random from the age-sex registers of one general practice in...

Shaper, A. G.; Wannamethee, G.; Macfarlane, P. W.; Walker, M.

1993-01-01

95

Sympathetic reinnervation and heart rate variability after cardiac transplantation.  

OpenAIRE

BACKGROUND: Heart rate variability is thought to measure autonomic modulation, but the relation has never been demonstrated directly in humans. AIM: To test the hypothesis that increased low frequency heart rate variability reflects sympathetic reinnervation after cardiac transplantation. PATIENTS: 24 cardiac transplant recipients at the time of routine surveillance coronary angiography two or more years after cardiac transplantation, and 10 controls with normal coronary arteries undergoing a...

Lord, S. W.; Clayton, R. H.; Mitchell, L.; Dark, J. H.; Murray, A.; Mccomb, J. M.

1997-01-01

96

Assessing resting heart rate in adolescents: determinants and correlates.  

OpenAIRE

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

97

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

OpenAIRE

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

98

DETECTING CONGESTIVE HEART FAILURE USING HEART RATE SEQUENTIAL TREND ANALYSIS PLOT  

Directory of Open Access Journals (Sweden)

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

99

Heart Rate Variability in Complex Regional Pain Syndrome during Rest and Mental and Orthostatic Stress  

DEFF Research Database (Denmark)

BACKGROUND:: Complex regional pain syndrome (CRPS) is a pain condition with regional sensory and autonomic abnormalities in the affected limb. The authors studied systemic autonomic and hemodynamic function in CRPS patients during rest, and during orthostatic and mental arithmetic stress. METHODS:: Twenty patients with CRPS and 20 age-, sex-, and body mass index-matched control subjects participated. Mean values of heart rate variability, baroreceptor sensitivity, blood pressure, stroke volume, cardiac output, and total peripheral resistance were estimated during supine rest and 60° tilt-table testing. On a separate day, heart rate variability was also measured during mental arithmetic stress testing induced by a paced auditory serial addition task. RESULTS:: Heart rate was increased and heart rate variability reduced in patients with CRPS patients compared with control subjects during rest and mental and orthostatic stress, whereas baroreceptor sensitivity was unaffected. When tilted from supine to upright position, patients with CRPS were not able to preserve cardiac output in comparison with control subjects, and they exhibited an exaggerated increase in the total peripheral resistance. The hemodynamic changes correlated to pain duration but not to pain intensity. CONCLUSIONS:: The increased heart rate and decreased heart rate variability in CRPS suggest a general autonomic imbalance, which is an independent predictor for increased mortality and sudden death. The inability of the patients to protect their cardiac output during orthostatic stress was aggravated with the chronicity of the disease.

Terkelsen, Astrid J; MØlgaard, Henning

2012-01-01

100

The effect of competition on heart rate during kart driving: A field study  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Both the act of competing, which can create a kind of mental stress, and participation in motor sports, which induces physical stress from intense g-forces, are known to increase heart rate dramatically. However, little is known about the specific effect of competition on heart rate during motor sports, particularly during four-wheel car driving. The goal of this preliminary study, therefore, was to investigate whether competition increases heart rate under such situations. Findings The participants drove an entry-level formula kart during two competitive races and during solo driving against the clock while heart rate and g-forces were measured. Analyses showed that heart rate values during the races (168.8 beats/min were significantly higher than those during solo driving (140.9 beats/min and rest (75.1 beats/min. Conclusions The results of this preliminary study indicate that competition heightens heart rate during four-wheel car driving. Kart drivers should be concerned about maintaining good health and developing physical strength.

Yamakoshi Takehiro

2011-09-01

101

Decreased heart rate variability in surgeons during night shifts  

DEFF Research Database (Denmark)

BACKGROUND: Heart rate variability (HRV) has been used as a measure of stress and mental strain in surgeons. Low HRV has been associated with death and increased risk of cardiac events in the general population. The aim of this study was to clarify the effect of a 17-hour night shift on surgeons' HRV. METHODS: Surgeons were monitored prospectively with an ambulatory electrocardiography device for 48 consecutive hours, beginning on a precall day and continuing through an on-call (17-h shift) day. We measured HRV by frequency domain parameters. RESULTS: We included 29 surgeons in our analysis. The median pulse rate was decreased precall (median 64, interquartile range [IQR] 56-70 beats per minute [bpm]) compared with on call (median 81, IQR 70-91 bpm, p < 0.001). Increased high-frequency (HF) activity was found precall (median 199, IQR 75-365 ms2) compared with on call (median 99, IQR 48-177 ms2, p < 0.001). The low-frequency:high-frequency (LF:HF) ratio was lower precall (median 2.7, IQR 1.9-3.9) than on call (median 4.9, IQR 3.7-6.5, p < 0.001). We found no correlation between the LF:HF ratio and performance in laparoscopic simulation. CONCLUSION: Surgeons working night shifts had a significant decrease in HRV and a significant increase in pulse rate, representing sympathetic dominance in the autonomic nervous system. TRIAL REGISTRATION: NCT01623674 (www.clinicaltrials.gov).

Amirian, Ilda; Toftegård Andersen, Lærke

2014-01-01

102

Cuff inflation during ambulatory blood pressure monitoring and heart rate  

Directory of Open Access Journals (Sweden)

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

Mia Skov-Madsen

2008-11-01

103

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

Science.gov (United States)

Background Experimental data suggests that exclusive heart rate reduction with ivabradine is associated with the amelioration of the endothelial function. Since it is presently unknown whether this also applies to humans, the aim of this pilot study was to investigate whether heart rate reduction with ivabradine modulates the endothelial function in humans with an established coronary heart disease. Methods Using high-sensitivity ultrasound, we analysed the flow-mediated (FMD) and nitro-mediated dilation (NMD) of the brachial artery in 25 patients (62.9?±?8.4 years) with a stable coronary heart disease and a resting heart rate of ?70 beats per minute (bpm). To assess acute effects, measurements were performed before and 4 hours after the first intake of ivabradine 7.5 mg. Sustained effects of an ivabradine therapy (5 mg to 7.5 mg twice daily) were investigated after 4 weeks. Results We found a significant decrease in heart rate, both 4 hours after the intake of 7.5 mg of ivabradine (median -8 [interquartile range (IQR) -14 to -4] bpm) and after 4 weeks of twice daily intake (median -10 [IQR-17 to -5] bpm) (p?ivabradine nor after sustained therapy (baseline FMD: median 5.0 [IQR 2.4 to 7.9]%; FMD 4 hours after 7.5 mg of ivabradine: median 4.9 [IQR 2.7 to 9.8]%; FMD after 4 weeks of ivabradine therapy: median 6.1 [IQR 4.3 to 8.2]%). No significant changes of the NMD were observed. In regression analysis, the heart rate and FMD did not correlated, irrespective of the ivabradine intake (r2?=?0.086). Conclusion In conclusion, in our study heart rate reduction through ivabradine does not improve the endothelial function in patients with a stable coronary heart disease. Moreover, we found no correlation between the heart rate and the endothelial function. PMID:24479706

2014-01-01

104

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

OpenAIRE

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

Davidovic, Goran; Iric-cupic, Violeta; Milanov, Srdjan; Dimitijevic, Aleksandra; Petrovic-janicijevic, Mirjana

2013-01-01

105

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  

Directory of Open Access Journals (Sweden)

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

106

BREAKDOWN OF SCALING PROPERTIES IN ABNORMAL HEART RATE VARIABILITY  

OpenAIRE

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 asso...

Rodri?guez, E.; Luca; Meraz, M.; Alvarez-ramirez, J.

2006-01-01

107

Quantification of fetal heart rate regularity using symbolic dynamics  

Science.gov (United States)

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

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

2007-03-01

108

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

OpenAIRE

Heart rate variability (HRV), the change in the time intervals between adjacent heartbeats, is an emergent property of interdependent regulatory systems that operate on different time scales to adapt to challenges and achieve optimal performance. This article briefly reviews neural regulation of the heart, and its basic anatomy, the cardiac cycle, and the sinoatrial and atrioventricular pacemakers. The cardiovascular regulation center in the medulla integrates sensory information and input fr...

Shaffer, Fred; Mccraty, Rollin; Zerr, Christopher L.

2014-01-01

109

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

Directory of Open Access Journals (Sweden)

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

110

Pulse rate variability compared with Heart Rate Variability in children with and without sleep disordered breathing.  

Science.gov (United States)

Heart Rate Variability (HRV), the variation of time intervals between heartbeats, is one of the most promising and widely used quantitative markers of autonomic activity. Traditionally, HRV is measured as the series of instantaneous cycle intervals obtained from the electrocardiogram (ECG). In this study, we investigated the estimation of variation in heart rate from a photoplethysmography (PPG) signal, called pulse rate variability (PRV), and assessed its accuracy as an estimate of HRV in children with and without sleep disordered breathing (SDB). We recorded raw PPGs from 72 children using the Phone Oximeter, an oximeter connected to a mobile phone. Full polysomnography including ECG was simultaneously recorded for each subject. We used correlation and Bland-Altman analysis for comparing the parameters of HRV and PRV between two groups of children. Significant correlation (r > 0.90, p < 0.05) and close agreement were found between HRV and PRV for mean intervals, standard deviation of intervals (SDNN) and the root-mean square of the difference of successive intervals (RMSSD). However Bland-Altman analysis showed a large divergence for LF/HF ratio parameter. In addition, children with SDB had depressed SDNN and RMSSD and elevated LF/HF in comparison to children without SDB. In conclusion, PRV provides the accurate estimate of HRV in time domain analysis but does not reflect precise estimation for parameters in frequency domain. PMID:24111246

Dehkordi, Parastoo; Garde, Ainara; Karlen, Walter; Wensley, David; Ansermino, J Mark; Dumont, Guy A

2013-01-01

111

The Use of Heart Rate Monitors in Physical Education  

Science.gov (United States)

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

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

2009-01-01

112

Reflection of heart rate regulation on linear and nonlinear heart rate variability measures.  

Science.gov (United States)

The aim of this study was to examine the dependence of heart rate variability (HRV) measures on RR interval length and to find out relationships between linear and nonlinear measures. The spectral powers in very low (VLF), low (LF) and high (HF) frequency regions, short-term scaling exponent alpha(1) and sample entropy (SampEn) were determined. All spectral powers increased with increasing RR interval length until they reached a plateau. Neighbouring spectral powers were strongly correlated. The largest fraction of the spectrum consisted of VLF (from about 40 to 95%) and the smallest of HF, although HF was most sensitive to changes in RR interval length. SampEn is also increased with increasing RR interval, reaching a plateau. The dependence of alpha(1) on RR showed a deflection point at 0.5 s. Nonlinear measures can be expressed by spectral powers: alpha(1) by a linear function of ln(LF/HF) and SampEn by a quadratic function of ln HF. We concluded that during the day an increase of HR up to 120 beats min(-1) was reflected in a reduction in HF and LF and to a smaller extent in VLF and by decreased complexity and increased correlation in RR interval series. In sleep, HRV measures are at a plateau. We suggest that below intrinsic value, HR is regulated mainly by changes of parasympathetic activity, reflected in linear and nonlinear HRV measures. PMID:16400201

Platisa, Mirjana M; Gal, Vera

2006-02-01

113

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

OpenAIRE

Heart rate reduction (HRR) is an important target in the management of patients with chronic stable angina. Most available drugs for HRR, such as ?-blockers, have adverse effects, including on cardiac energy substrate metabolism, a well-recognized determinant of cardiac homeostasis. This study aimed at 1) testing whether HRR by ivabradine (IVA) alters substrate metabolism in the healthy normoxic working heart and 2) comparing the effect of IVA with that of the ?-blocker metoprolol (METO). T...

Lauzier, Benjamin; Vaillant, Fanny; Ge?linas, Roselle; Bouchard, Bertrand; Brownsey, Roger; Thorin, Eric; Tardif, Jean-claude; Rosiers, Christine Des

2011-01-01

114

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

Directory of Open Access Journals (Sweden)

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

115

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

Directory of Open Access Journals (Sweden)

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

Ping Liu

2011-06-01

116

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

OpenAIRE

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

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

2005-01-01

117

Reliability of spectral analysis of fetal heart rate variability.  

Science.gov (United States)

Spectral analysis of fetal heart rate variability could provide information on fetal wellbeing. Unfortunately, fetal heart rate recordings are often contaminated by artifacts. Correction of these artifacts affects the outcome of spectral analysis, but it is currently unclear what level of artifact correction facilitates reliable spectral analysis. In this study, a method is presented that estimates the error in spectral powers due to artifact correction, based on the properties of the Continuous Wavelet Transformation. The results show that it is possible to estimate the error in spectral powers. The information about this error makes it possible for clinicians to assess the reliability of spectral analysis of fetal heart rate recordings that are contaminated by artifacts. PMID:25570577

Warmerdam, G J J; Vullings, R; Bergmans, J W M; Oei, S G

2014-01-01

118

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

Directory of Open Access Journals (Sweden)

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

García-García Ángel

2012-03-01

119

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

OpenAIRE

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...

Chen, Man; Niestemski, Liang Ren; Prevost, Robert; Mcrae, Michael; Cholleti, Sharath; Najarro, Gabriel; Buchman, Timothy G.; Deem, Michael W.

2013-01-01

120

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)

121

Relationship between anxiety, heart rate and efficiency of pistol shooting  

OpenAIRE

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. ...

Gürhan Kayihan; Gülfem Ersoz; Ali Özkan; Mercan Tuna

2014-01-01

122

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

Science.gov (United States)

Heart rate variability (HRV), the change in the time intervals between adjacent heartbeats, is an emergent property of interdependent regulatory systems that operate on different time scales to adapt to challenges and achieve optimal performance. This article briefly reviews neural regulation of the heart, and its basic anatomy, the cardiac cycle, and the sinoatrial and atrioventricular pacemakers. The cardiovascular regulation center in the medulla integrates sensory information and input from higher brain centers, and afferent cardiovascular system inputs to adjust heart rate and blood pressure via sympathetic and parasympathetic efferent pathways. This article reviews sympathetic and parasympathetic influences on the heart, and examines the interpretation of HRV and the association between reduced HRV, risk of disease and mortality, and the loss of regulatory capacity. This article also discusses the intrinsic cardiac nervous system and the heart-brain connection, through which afferent information can influence activity in the subcortical and frontocortical areas, and motor cortex. It also considers new perspectives on the putative underlying physiological mechanisms and properties of the ultra-low-frequency (ULF), very-low-frequency (VLF), low-frequency (LF), and high-frequency (HF) bands. Additionally, it reviews the most common time and frequency domain measurements as well as standardized data collection protocols. In its final section, this article integrates Porges' polyvagal theory, Thayer and colleagues' neurovisceral integration model, Lehrer et al.'s resonance frequency model, and the Institute of HeartMath's coherence model. The authors conclude that a coherent heart is not a metronome because its rhythms are characterized by both complexity and stability over longer time scales. Future research should expand understanding of how the heart and its intrinsic nervous system influence the brain. PMID:25324790

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

2014-01-01

123

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

124

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

125

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

126

Volitional Control of Heart Rate During Exercise Stress.  

Science.gov (United States)

Thirty five volunteer college women were divided into three groups to determine if heart rate could be conditioned instrumentally and lowered during exercise stress on the treadmill. The three groups were a) experimental group I, 15 subjects who received instrumental conditioning with visual feedback; b) instrumental group II, 9 subjects who…

LeFevers, Victoria A.

127

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

128

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

129

Nonlinear analysis of heart rate dynamics in hyperthyroidism.  

Science.gov (United States)

Studies on the physiology of the cardiovascular system suggested that the generation of the heart rate signal is governed by nonlinear chaotic dynamics. No study investigated the nonlinear dynamics of heart rate in hyperthyroidism. We examined whether the heart rate dynamics of hyperthyroid patients is different from normal controls by the nonlinear analysis of heart rate variability (HRV) with correlation dimension (CD). Thirty-three hyperthyroid Graves' disease patients (30 females and 3 males; age 31 +/- 1 years, means +/- SE) and 33 sex-, age-, and body mass index-matched normal controls were recruited to receive one-channel electrocardiogram recording for 30 min. The CD, an index of complexity, was computed from the sequence of normal R-R intervals by the Grassberger and Procaccia algorithm. Compared to the normal controls, the hyperthyroid patients showed significant reductions (P HRV. In addition, the decreased CD in hyperthyroid patients implies reduced complexity and impaired tolerance to cardiovascular stresses in hyperthyroidism. This finding helps to explain exercise intolerance and irritability manifested by the hyperthyroid patients. PMID:17395997

Chen, Jin-Long; Tseng, Yin-Jiun; Chiu, Hung-Wen; Hsiao, Tzu-Chien; Chu, Woei-Chyn

2007-04-01

130

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

131

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

132

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

OpenAIRE

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

133

Multivariate short-term heart rate variability: a pre-diagnostic tool for screening heart disease.  

Science.gov (United States)

This study has aimed to develop a novel pre-diagnostic tool for primary care screening of heart disease based on multivariate short-term heart rate variability (HRV) analyzed by linear (time and frequency domain) and nonlinear methods (compression entropy (CE), detrended fluctuation analysis (DFA), Poincaré plot analysis, symbolic dynamics) applied to 5-min ECG segments. Firstly, we applied HRV analysis to separate healthy subjects (REF) from heart disease patients (PAT). Then to optimize the results, we subdivided both groups according to gender: REF (? = 78, ? = 53) versus PAT (? = 378, ? = 115). Finally, we divided REF and PAT into two age subgroups (30-50 years vs. 51-70 years of age) to consider the influence of age on HRV. Heart disease patients were classified using a scoring system based on cut-off values calculated from all HRV indices obtained from the REF. After combining the optimum indices from all different analyzing methods, sensitivities of more than 72% and a specificity of 100% in all subgroups were revealed. Nonlinear indices proved to be better for discriminating heart disease patients from healthy subjects. Multivariate short-term HRV, analyzed by both linear and nonlinear methods appears to be a suitable pre-diagnostic tool for screening heart disease in primary care settings. PMID:21140234

Heitmann, Andreas; Huebner, Thomas; Schroeder, Rico; Perz, Siegfried; Voss, Andreas

2011-01-01

134

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

135

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

136

Determination of Heart Rate from ECG Signal- A Simplified Approach  

Directory of Open Access Journals (Sweden)

Full Text Available Electrocardiography is a non-invasive technique of registration of the electrical activity of the heart and is widely used as a diagnostic tool by the physicians. ECG signal yields information about the conditions of the heart. Among many morphological markers of the ECG, the QRS complex and the R-peaks are the most significant ones---with the contribution of the R-peak to RR interval being a driving factor. The number of R-peaks in a specified interval leads to the determination of the heart rate in beats per minute. This calls for an efficient R-peak detection algorithm. The authors have suggested here a straight-forward algorithm, the efficacy of which has been improved by enhancing the quality of the ECG signal by EMD method. The performance has been compared with Pan-Tompkins algorithm---a benchmark method and also against the original values obtained from MIT/BIH database.

Sautami Basu*,

2014-12-01

137

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

Science.gov (United States)

Background Despite the routine prescription of rate control therapy for atrial fibrillation (AF), clinical evidence demonstrating a heart rate target is lacking. Aim of the present study was to run a mathematical model simulating AF episodes with a different heart rate (HR) to predict hemodynamic parameters for each situation. Methods The lumped model, representing the pumping heart together with systemic and pulmonary circuits, was run to simulate AF with HR of 50, 70, 90, 110 and 130 bpm, respectively. Results Left ventricular pressure increased by 57%, from 33.92±37.56 mmHg to 53.15±47.56 mmHg, and mean systemic arterial pressure increased by 27%, from 82.66±14.04 mmHg to 105.3±7.6 mmHg, at the 50 and 130 bpm simulations, respectively. Stroke volume (from 77.45±8.50 to 39.09±8.08 mL), ejection fraction (from 61.10±4.40 to 39.32±5.42%) and stroke work (SW, from 0.88±0.04 to 0.58±0.09 J) decreased by 50, 36 and 34%, at the 50 and 130 bpm simulations, respectively. In addition, oxygen consumption indexes (rate pressure product – RPP, tension time index per minute – TTI/min, and pressure volume area per minute – PVA/min) increased from the 50 to the 130 bpm simulation, respectively, by 186% (from 5598±1939 to 15995±3219 mmHg/min), 56% (from 2094±265 to 3257±301 mmHg s/min) and 102% (from 57.99±17.90 to 117.4±26.0 J/min). In fact, left ventricular efficiency (SW/PVA) decreased from 80.91±2.91% at 50 bpm to 66.43±3.72% at the 130 bpm HR simulation. Conclusion Awaiting compulsory direct clinical evidences, the present mathematical model suggests that lower HRs during permanent AF relates to improved hemodynamic parameters, cardiac efficiency, and lower oxygen consumption. PMID:25764321

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

2015-01-01

138

Oxygen Kinetics and Heart Rate Response during Early Recovery from Exercise in Patients with Heart Failure  

OpenAIRE

Background. The purpose of this study was to assess the post-exercise O2 uptake and heart rate response in patients with heart failure (HF) in comparison to healthy individuals. Methods and Results. Exercise testing of all subjects was conducted according to the RITE-protocol. The study subjects were classified according to their peak oxygen uptake (peak VO2) in four groups: healthy individuals with a peak VO2 >22?mL/kg/min (group 1, n: 50), and patients with HF and a peak VO2 of 18–22?...

Kriatselis, Charalampos D.; Sotirios Nedios; Sebastian Kelle; Sebastian Helbig; Martin Gottwik; Christian von Bary

2012-01-01

139

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

140

Complexity of the short-term heart-rate variability.  

Science.gov (United States)

This work has proposed a methodology based on the concept of entropy rates to study the complexity of the short-term heart-rate variability (HRV) for improving risk stratification to predict sudden cardiac death (SCD) of patients with established ischemic-dilated cardiomyopathy (IDC). The short-term HRV was analyzed during daytime and nighttime by means of RR series. An entropy rate was calculated on the RR series, previously transformed to symbol sequences by means of an alphabet. A statistical analysis permitted to stratify high- and low-risk patients of suffering SCD, with a specificity (SP) of 95% and sensitivity (SE) of 83.3%. PMID:19914891

Valencia, Jose F; Vallverdú, Montserrat; Schroeder, Rico; Voss, Andreas; Vázquez, Rafael; Bayés de Luna, Antonio; Caminal, Pere

2009-01-01

141

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

142

Reduced Heart Rate Variability Among Youth With Type 1 Diabetes  

Science.gov (United States)

OBJECTIVE This study compared heart rate variability (HRV) parameters in youth with and without type 1 diabetes and explored potential contributors of altered HRV. RESEARCH DESIGN AND METHODS HRV parameters were measured among 354 youth with type 1 diabetes (mean age 18.8 years, diabetes duration 9.8 years, and mean A1C 8.9%) and 176 youth without diabetes (mean age 19.2 years) participating in the SEARCH CVD study. Multiple linear regression was used to assess the relationship between diabetes status and HRV parameters, adjusting for covariates. RESULTS Compared with control subjects, youth with type 1 diabetes had reduced overall HRV (10.09 ms lower SD of NN intervals [SDNN]) and markers of parasympathetic loss (13.5 ms reduced root mean square successive difference of NN intervals [RMSSD] and 5.2 normalized units (n.u.) reduced high frequency [HF] power) with sympathetic override (5.2 n.u. increased low frequency [LF] power), independent of demographic, anthropometric, and traditional cardiovascular risk factors. Older age, female sex, higher LDL cholesterol and triglyceride levels, and presence of microalbuminuria were independently associated with lower HRV but did not account for the observed differences between youth with and without diabetes. Youth with type 1 diabetes and A1C levels ?7.5% had significantly worse HRV parameters than control subjects; however, in youth with optimal glycemic control (A1C <7.5%), HRV parameters did not differ significantly from control subjects. CONCLUSIONS Youth with type 1 diabetes have signs of early cardiac autonomic neuropathy: reduced overall HRV and parasympathetic loss with sympathetic override. The main driver of these subclinical abnormalities appears to be hyperglycemia. PMID:22961570

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

2013-01-01

143

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

Scientific Electronic Library Online (English)

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

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

144

Heart rate during exercise: what is the optimal goal of rate adaptive pacemaker therapy?  

Science.gov (United States)

The objective of minute ventilation (MV)-controlled pacemaker algorithms is to simulate the physiologic relationship of the sensed signal and the sinus node response during exercise. In our study we determined the relationship between heart rate and MV in healthy middle-aged subjects by measuring breath-by-breath gas exchange throughout peak exercise. Regarding several clinical limitations of peak exercise testing, we additionally evaluated whether a 35 W low-intensity treadmill exercise (LITE) protocol can be used as a substitute for peak exercise testing to determine the physiologic heart rate to MV slope. The results demonstrated that the heart rate to MV relationship is not linear throughout peak exercise but is curvilinear with a smooth logarithmic-type profile. To simulate this relationship, MV-based rate adaptive pacemakers should generate a decreasing heart rate to MV slope during higher levels of work. The heart rate to MV slope determined during the early, dynamic phase of low-intensity exercise represents the same slope derived from peak exercise below the anaerobic threshold. The low-intensity treadmill exercise protocol, with minimal patient effort, can thus be used as a substitute for peak exercise to optimize rate adaptive slope programming of MV-controlled pacemakers. PMID:8160576

Lewalter, T; Jung, W; MacCarter, D; Bauer, T; Schimpf, R; Manz, M; Lüderitz, B

1994-04-01

145

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

146

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

147

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

148

Comparison of heart rate variability adjusted for age and heart rate in women with rheumatoid arthritis and women without rheumatic diseases  

Directory of Open Access Journals (Sweden)

Full Text Available Aim. To compare the 24-hour indicators of heart rate variability (HRV, adjusted for age and 24-hour average heart rate (HR24 in women with rheumatoid arthritis (RA and womenof the control group.Material and methods. Women with RA (n=291 at the age of 20-60 were examined. Women without rheumatic diseases (n=125 were included into control group. The presenceof traditional cardiovascular risk factors, the results of 24-hour ECG monitoring were assessed in addition to clinical symptoms, RA activity and severity. Transformation ofthe initial HRV parameters in their logarithms, and the standardization of the logarithms of age and HR24, the calculation of the exponential of the standardized logarithm wereperformed to remove the effects of age and heart rate on HRV.Results. Time and frequency HRV indices, adjusted for age and HP24 (HRVa in women with RA were lower than these in women of control group. HRVa decline was observed in14–24% of women with RA. The maximum HRVa decrease was observed among the parameters that reflect an activity of parasympathetic autonomic nervous system (RMSSDn,pNN50n, HFn.Conclusion. The young and middle age women with RA differ from the women of the control group in significant decrease in the time and spectral HRV indices adjusted forage and HR24.

D.S. Novikova

2013-04-01

149

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)

150

Quantitative Assessment of Heart Rate Changes Due to Therapeutic Interventions*  

OpenAIRE

Continuous monitoring of electrophysiologic and hemodynamic disturbances in critically ill patients has significantly improved the physicians ability to assess responses to therapeutic interventions, such as the infusion of a drug, and non-therapeutic interventions, such as the exercise stress test. Quantitative assessment of heart rate changes for extended studies is not practical without a computer-based system. This paper describes a computerized continuous electrocardiographic interval (C...

Ball, Thomas A.; Strand, Eugene M.; Mantle, John A.

1980-01-01

151

Increased heart rate and atherosclerosis: Potential implications of ivabradine therapy  

OpenAIRE

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

Alberto Dominguez-Rodriguez; Gabriela Blanco-Palacios; Pedro Abreu-Gonzalez

2011-01-01

152

The Effect of Mindfulness on Heart Rate Control  

OpenAIRE

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

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

2009-01-01

153

Heart rate analysis in normal subjects of various age groups  

OpenAIRE

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 Poi...

Ping Luk; Sing Ong; Kannathal, N.; Rajendra, Acharya U.; Chua TjiLeng

2004-01-01

154

Elevated resting heart rate is associated with the metabolic syndrome  

OpenAIRE

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 partic...

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

2009-01-01

155

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

OpenAIRE

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

156

Oximetry, heart rate variability, and the diagnosis of mild-to-moderate acute mountain sickness.  

Science.gov (United States)

The clinical evaluation of acute mountain sickness (AMS) is often performed in remote settings with minimal equipment. The purpose of this study was to examine the utility of heart rate variability and other cardiovascular parameters in a high-altitude clinical setting. Forty-one participants were recruited from the patient population of the clinic, and from festivalgoers [those who attended the Janai Purnima festival held at Lake Gosainkunda (4380?m) in Langtang, Nepal] in the vicinity of the clinic. Twenty-one participants were diagnosed with AMS; remaining participants were free from altitude illness. Heart rate variability (both time and frequency domain measures), arterial oxygen saturation (SpO2), blood pressure and Lake Louise Score were evaluated in all the participants. Oxygen saturation and diastolic blood pressure were negatively and positively correlated with Lake Louise Score, respectively. Receiver operating characteristic analysis indicated that an SpO2 of 86% or greater was associated with a very low likelihood of AMS at this altitude. No heart rate variability parameters were different in the AMS group as compared with the control group. In conclusion, in patients with SpO2 of 86% or more at 4380?m or higher, the likelihood of AMS is low. Diastolic blood pressure correlated with AMS severity, whereas heart rate variability was not useful in the diagnosis of AMS. PMID:19641462

Koehle, Michael S; Guenette, Jordan A; Warburton, Darren E R

2010-04-01

157

Do ventricular repolarization interval ratios depend on heart rate and should they be rate-corrected?  

OpenAIRE

QT interval decreases with increasing heart rate (HR), hence to define normal values of QT interval for different heart rates requires the application of a QT interval rate correction formula. However, the influence of HR on the ratios between several ventricular repolarization intervals, that can be useful as risk predictors of malignant ventricular arrhythmias is unknown. This study analyzes the influence of HR on QTp/QT, JTp/JT, Tpe/JTp, and Tpe/JT ratios on a healthy subject during exerci...

Alvarado Serrano, Carlos; Ramos Castro, Juan Jose?; Palla?s Areny, Ramon

2002-01-01

158

Blood pressure and heart rate in patients with ischaemic heart disease receiving nifedipine and propranolol.  

OpenAIRE

A randomised controlled crossover trial was performed to assess the anti-anginal effects of nifedipine and propranolol separately and together. The effects of these treatments on blood pressure and heart rate were assessed at rest and after the cold pressor and mental arithmetic tests. Nifedipine and propranolol together produced the greatest reduction in supine and erect systolic and diastolic blood pressures. Propranolol (480 mg daily) lowered resting systolic/diastolic blood pressures by 7...

Harris, L.; Dargie, H. J.; Lynch, P. G.; Bulpitt, C. J.; Krikler, D. M.

1982-01-01

159

24-hour electrocardiographic study of heart rate and rhythm patterns in population of healthy children.  

OpenAIRE

Twenty-four hour electrocardiographic recordings were made on 104 randomly selected, healthy 7 to 11-year-old children. Ninety-two were technically adequate and suitable for analysis. The mean highest heart rate measured by direct electrocardiographic analysis over nine beats was 164 +/- 17. The mean lowest heart rates were 49 +/- 6 over three beats', and 56 +/- 6 over nine beats' duration. The maximum duration of heart rates less than 55/minute was 40 minutes. At their lowest heart rates 41 ...

Southall, D. P.; Johnston, F.; Shinebourne, E. A.; Johnston, P. G.

1981-01-01

160

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

2013-01-01

161

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

162

Heart rate dynamics in doxorubicin-induced cardiomyopathy.  

Science.gov (United States)

The clinical use of doxorubicin, an effective chemotherapeutic is hampered by the development of irreversible cardiotoxicity. Here we test time-frequency analysis of heart rate (HR) variability (HRV) for early detection of doxorubicin-induced cardiotoxicity. Experiments were conducted in adult male Wistar rats treated for 15?days with doxorubicin (DOXO, total dose 15?mg?kg(-1), i.p.) or saline (CONT). DOXO rats exhibited cardiotoxicity confirmed by histological examination without developing heart failure as estimated by echocardiography. However, HR variability increase reflected subtle microscopic changes of cardiac toxicity in DOXO rats. The results recommend time-frequency analysis of HRV for early detection of doxorubicin-induced cardiomyopathy. PMID:25798626

Lon?ar-Turukalo, T; Vasi?, M; Tasi?, T; Mijatovi?, G; Glumac, S; Baji?, D; Japunži?-Žigon, N

2015-04-01

163

Analysis of heart rate variability using fuzzy measure entropy.  

Science.gov (United States)

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

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

2013-02-01

164

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

Science.gov (United States)

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

Stone, Michael H.; And Others

1987-01-01

165

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

166

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

167

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

168

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

169

Autonomic response to tactical pistol performance measured by heart rate variability.  

Science.gov (United States)

Thompson, AG, Swain, DP, Branch, JD, Spina, RJ, and Grieco, CR. Autonomic response to tactical pistol performance measured by heart rate variability. J Strength Cond Res 29(4): 926-933, 2015-This study evaluated changes in autonomic tone during a tactical pistol competition. At rest and during a match, heart rate variability (HRV) was examined in 28 healthy subjects. Heart rate variability time-domain variables (including interbeat interval [IBI]) and frequency-domain variables (low frequency [LF], high frequency [HF], total power [TP]) measured during shooting were subtracted from those measured during rest to produce ?s. The shooting task involved several, rapid tactical maneuvers. Raw time to completion and inaccurate shots (points down [PDs]) were recorded and combined to form a match score where lower values indicated superior shooting performance. Mean (±SD) raw time was 135.9 ± 34.1 seconds, PDs were 78 ± 34, and match score was 175.3 ± 39.8. Shooting decreased IBI (i.e., increased heart rate) and LF. ?LF, ?HF, and ?TP were independent of ?IBI. Raw time was significantly (p ? 0.05) correlated to shooting IBI (r = 0.404) and ?IBI (r = -0.426). Points down were significantly correlated to ?TP (r = 0.416) and ?LF (r = 0.376). Match score was significantly correlated to ?IBI (r = -0.458), ?HF (r = 0.467), ?LF (r = 0.377), and ?TP (r = 0.451). In conclusion, individuals with a greater decrease in IBI (and thus heart rate) performed better by accomplishing the match faster. Individuals with less change in stress-related HRV measures (LF, HF, and TP) performed better through improved accuracy. Thus, HRV-derived sympathetic response is significantly related to shooting performance and should be used to assess marksmanship effectiveness under duress. PMID:25029000

Thompson, Andrew G; Swain, David P; Branch, J David; Spina, Robert J; Grieco, Carmine R

2015-04-01

170

Prognostic value of the exercise heart rates in the stress myocardial perfusion imaging on cardiac events  

International Nuclear Information System (INIS)

Full text: Objectives: To evaluate the clinical value of the exercise heart rate (HR) in the stress myocardial perfusion imaging (MPI) and cardiac events (CE). Methods: All pts underwent exercise MPI after symptom-limited exercise treadmill testing by Bruce protocol. Heart rate, blood pressure, and 3- lead ECGS were recorded during exercise. The mean interval of following up was 29.75±9.73 (1?27) months. The mean stress amount was 3.79±0.93 (2-6) degrees, and the mean lasted time was 14.80±2.42 (6-20) minutes. Results: A total number of 346 pts (233 M/113 F; mean age 51.73±9.88 years). According to the exercise HR reached submaximal dose or not, the pts were divided into G1 (n=294, HR reached submaximal dose) and G2 (n=52, HR didn't reach submaximal dose). Over all, there were 85 pts with positive MPI in G1, but only 22 pts in G2 (Pearson chisquare 9.018, P < 0.05). The rate of CE occurrence in G1 and G2 is 2.7% and 17.3% respectively (Pearson chisquare20.123, P <0.05). The positive MPI result and the rate of CE in G2 were higher than G1. Conclusions: In the exercise MPI, the heart rate which don't reach submaximal dose may predict the presence of abnormal MPI and subsequent CE. (author)

171

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

172

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

OpenAIRE

The heart rate is one of the significant physiological parameters of the human cardiovascular system. Heart rate is the number of times the heart beats per minute. Heart rate data reflects various physiological states such as biological workload, stress at work and concentration on tasks, drowsiness and the active state of the autonomic nervous system. Human cardiac dynamics are driven by the complex nonlinear interactions of two competing forces: sympathetic regulation increases and parasymp...

Souvik Das

2013-01-01

173

Simple and Cost-effective Heart Rate Meter Using PIC Microcontroller  

OpenAIRE

One of the major and significant physiological parameters of human cardiovascular system is the heart rate. Heart rate is represented by the number of times the heart beats per minute. The heart rate data can reflect various physiological states such as stress at work, concentration on tasks, drowsiness, biological workload, and the active state of the autonomic nervous system. Human cardiac dynamics are driven by the complex nonlinear interactions of two competing forces: sym...

Souvik Das

2014-01-01

174

Familial and genetic influences on heart rate variability.  

Science.gov (United States)

The authors tested the hypothesis of a genetic influence on heart rate variability (HRV). This genetic influence was assessed in 62, twin pairs (30 monozygotic, 32 dizygotic). From all twins, long-term electrocardiographic records were obtained, edited, and analyzed. Heart rate variability analysis was performed on the basis of parameters from time-domain, frequency-domain, and nonlinear dynamics. First, the parameter distances between the two twins of a pair and between one of the two and a third randomly selected person of another age-matched twin pair (ST1) were compared. Second, the parameter distances between the two twins and the averaged parameter distances of these two twins to all other age-matched persons (ST2) were compared. Finally, the averaged differences in parameter values between monozygotic and dizygotic age-matched twin pairs were compared. For statistical analysis, the nonparametric Wilcoxon's matched-pair signed rank test and parametric t-test for paired samples were used. Twin pairs show a significant lower difference in parameter values than other randomly selected and age-matched couples (P < .001 in ST1 and ST2). This reflects a considerable familial influence. Most parameters of the time-domain, none of the frequency-domain, and half of the nonlinear dynamics show significant differences between twin pairs and nontwin pairs. As a result of the comparison between monozygotic and dizygotic twin pairs, a significant lower parameter difference in the monozygotic pairs (P < .05) is found. These results suggest that there is a genetic component in heart rate generation and HRV, in addition to family environmental influences. Analysis of HRV might become a useful method in phenotyping severe genetic changes in cardiovascular diseases. PMID:9238392

Voss, A; Busjahn, A; Wessel, N; Schurath, R; Faulhaber, H D; Luft, F C; Dietz, R

1996-01-01

175

Correlation of sleep EEG frequency bands and Heart Rate Variability.  

Science.gov (United States)

Sleep apnoea is a sleep breathing disorder which causes changes in cardiac and neuronal activity and discontinuities in sleep pattern when observed via electrocardiogram (ECG) and electroencephalogram (EEG). This paper presents a pilot study result of assessing the correlation between EEG frequency bands and ECG Heart Rate Variability (HRV) in normal and sleep apnoea human clinical patients at different sleep stages. In sleep apnoea patients, the results have shown that EEG delta, sigma and beta bands exhibited a strong correlation with cardiac HRV parameters at different sleep stages. PMID:19965034

Abdullah, Haslaile; Holland, Gerard; Cosic, Irena; Cvetkovic, Dean

2009-01-01

176

Genetic locus on mouse chromosome 7 controls elevated heart rate  

OpenAIRE

Elevated heart rate (HR) is a risk factor for cardiovascular diseases. The goal of the study was to map HR trait in mice using quantitative trait locus (QTL) analysis followed by genome-wide association (GWA) analysis. The first approach provides mapping power and the second increases genome resolution. QTL analyses were performed in a C3HeB×SJL backcross. HR and systolic blood pressure (SBP) were measured by the tail-cuff plethysmography. HR was ?80 beats/min higher in SJL compared with C...

Smolock, Elaine M.; Ilyushkina, Irina A.; Ghazalpour, Anatole; Gerloff, Janice; Murashev, Arkady N.; Lusis, Aldons J.; Korshunov, Vyacheslav A.

2012-01-01

177

Heart Rate and Motion Analysis by GPS in Beach Soccer  

OpenAIRE

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...

Julen Castellano; David Casamichana

2010-01-01

178

Correlation between heart rate and performance during Olympic windsurfing competition  

OpenAIRE

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 (VO2max) trial and national windsurf competitions wearing a HR monitor. One hundred and forty-three individ...

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

2003-01-01

179

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 (REM sleep.

Papasimakis, N.; Pallikari, F.

2010-05-01

180

POSTURAL CHANGES IN HEART RATE AND BLOOD PRESSURE WITH AGEING  

OpenAIRE

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. Grou...

Pujitha, K.; Parvathi, G.; Muni Sekhar, K.

2014-01-01

181

Resting heart rate: risk indicator and emerging risk factor in cardiovascular disease.  

Science.gov (United States)

Resting heart rate is central to cardiac output and is influenced by changes occurring in numerous diseases. It predicts longevity and cardiovascular diseases, and current evidence suggests that it is also an important marker of outcome in cardiovascular disease, including heart failure. Beta-blockers improve outcomes in heart failure; however, they have effects outside reducing heart rate. Ivabradine has demonstrated efficacy in reducing rehospitalizations and mortality in heart failure and in improving exercise tolerance and reducing angina attacks in patients with coronary artery disease, whereas selective heart rate reduction may also prove to be beneficial in therapeutic areas outside those in which ivabradine has already demonstrated clinical efficacy. This review provides an update on the associations between heart rate and cardiovascular outcomes in various conditions, the experimental effects of heart rate reduction with ivabradine, and the potential new indications in cardiovascular disease. PMID:25447617

Böhm, Michael; Reil, Jan-Christian; Deedwania, Prakash; Kim, Jae B; Borer, Jeffrey S

2015-03-01

182

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

183

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

184

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

185

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

186

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

Science.gov (United States)

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

187

Contact-free heart rate measurement using multiple video data  

Science.gov (United States)

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

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

2013-10-01

188

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

189

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

Energy Technology Data Exchange (ETDEWEB)

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

190

Home telemonitoring of respiratory activity and heart rate variability in chronic heart failure patients: The challenge of the home or hospital in heart failure project  

OpenAIRE

Nocturnal respiratory disorders and depressed heart rate variability are known predictors of poor prognosis in chronic heart failure (CHF) patients. Intermittent monitoring of cardiorespiratory signals while the patient is at home might thus allow early identification of clinical deterioration and prompt optimization of treatment, leading to reduced hospitalizations and mortality and improved quality of life. Within the European Community multicenter trial HHH (Home or Hospital in Heart Failu...

Pinna, Gd; Maestri, R.; Gobbi, E.; La Rovere, Mt; Scanferlato, Jl; Witkowski, T.; Kus-klinowska, A.; Andrews, D.; Johnson, P.; Capomolla, S.; Mortara, A.

2003-01-01

191

Cortisol release, heart rate and heart rate variability in the horse and its rider: different responses to training and performance.  

Science.gov (United States)

Although some information exists on the stress response of horses in equestrian sports, the horse-rider team is much less well understood. In this study, salivary cortisol concentrations, heart rate (HR) and heart rate variability (HRV), SDRR (standard deviation of beat-to-beat interval) and RMSSD (root mean square of successive beat-to-beat intervals) were analysed in horses and their riders (n=6 each) at a public performance and an identical rehearsal that was not open to the public. Cortisol concentrations increased in both horses and riders (Pperformance and rehearsal. HR in horses and riders increased during the rehearsal and the public performance (Pincrease in HR was more pronounced (Pperformance (from 91 ± 10 to 150 ± 15 beats/min) compared to the rehearsal (from 94 ± 10 to 118 ± 12 beats/min). The SDRR decreased significantly during the equestrian tasks in riders (Pperformance, indicating a decrease in parasympathetic tone. The decrease in RMSSD in the riders was more pronounced (Pperformance (from 32.6 ± 6.6 to 3.8 ± 0.3 ms) than during the rehearsal (from 27.5 ± 4.2 to 6.6 ± 0.6 ms). The study has shown that the presence of spectators caused more pronounced changes in cardiac activity in the riders than it did in their horses. PMID:23380228

von Lewinski, Mareike; Biau, Sophie; Erber, Regina; Ille, Natascha; Aurich, Jörg; Faure, Jean-Michel; Möstl, Erich; Aurich, Christine

2013-08-01

192

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 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

193

Ivabradine: a new rate-limiting therapy for coronary artery disease and heart failure  

OpenAIRE

Ivabradine is a new bradycardic agent acting on the If channels of sinoatrial nodal cells to decrease the rate of diastolic depolarization and thus heart rate. The benefit of ivabradine over other negatively chronotropic agents is its absence of negative inotropy. Effective management of coronary artery disease, in terms of reducing morbidity and mortality, is reliant on controlling heart rate. Ivabradine has been shown to safely and effectively reduce heart rate without compromising cardiac ...

Rushworth, Gordon F.; Lambrakis, Philippe; Leslie, Stephen J.

2011-01-01

194

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

Directory of Open Access Journals (Sweden)

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

195

Esmolol for septic shock: more than just heart rate control?  

Science.gov (United States)

Excessive adrenergic stimulation may be associated with several adverse events and contribute to increase mortality in critically ill septic patients. Few clinical data exist on the effects of adrenergic blockade in this setting. The objective of this study was to investigate the effect of a short acting b-blocker (esmolol) in septic shock patients. In a single-center, controlled, open-label, phase 2 trial (from November 2010 to July 2012), Morelli et al. randomized patients with a need of norepinephrine to maintain a mean arterial pressure above 65 mmHg to receive either esmolol or standard of care. Patients were included if, after 24 hours of initial resuscitation, hypovolemia was excluded (wedge pressure ?12 mmHg or central venous pressure ?8 mmHg) and heart rate was above 95 bpm. Patients were excluded if they were younger than 18 years, had previous b-blockers therapy, cardiac index was ?2.2 L/min/m² with wedge pressure >18 mmHg, were diagnosed with significant cardiac valvular diseases or were pregnant. The primary outcome was the reduction in heart rate between 80 and 94 bpm over a 96-hr period. Secondary outcomes included norepinephrine requirement, hemodynamic changes, organ function, adverse events and 28-day mortality. A total of 154 patients, 77 for each group, were enrolled. Esmolol was more effective than standard treatment to reduce heart rate within target limits; also, b-blocker therapy was associated with an increased stroke volume and left ventricular work index when compared to the control group. These favorable hemodynamic effects were associated with a better control of lactate levels, a higher reduction in norepinephrine and fluids requirement. Mortality was 49.4% in the esmolol group and 80.5% in the control group (P<0.01). This is the first study showing an improvement in cardiac function and 28-day mortality in septic patients adding b-blockers to standard therapy. We discussed several statistical and methodological limitations that may influence the generability of these results. PMID:24500140

Orbegozo Cortes, D; Njimi, H; Dell'Anna, A M; Taccone, F S

2014-02-01

196

Freqüência cardíaca e risco cardiovascular Heart rate and cardiovascular risk  

Directory of Open Access Journals (Sweden)

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

197

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.

2007-10-01

198

Association between resting heart rate and N-terminal pro-brain natriuretic peptide in a community-based population study in Beijing  

Directory of Open Access Journals (Sweden)

Full Text Available Ruihua Cao, Yongyi Bai, Ruyi Xu, Ping Ye Department of Geriatric Cardiology, Chinese PLA General Hospital, Beijing, People’s Republic of China Background: N-terminal pro-brain natriuretic peptide (NT-proBNP is associated with an increased risk of cardiac insufficiency, which possibly leads to heart failure. However, the relationship between resting heart rate and NT-proBNP is unclear.Objective: This study focuses on this relativity between resting heart rate and plasma NT-proBNP levels in a surveyed community-based population.Methods: We evaluated the relativity between resting heart rate and plasma levels of NT-proBNP in 1,567 participants (mean age 61.0 years, range 21–96 years from a community-based population in Beijing, People’s Republic of China.Results: In patients with high resting heart rate (?75 beats/min, NT-proBNP was higher than in those having low resting heart rate (<75 beats/min. In multiple linear stepwise regression analysis, plasma NT-proBNP was associated with resting heart rate (partial correlation coefficient, 0.82; 95% confidence interval, 0.18–1.51; P=0.011. A subsequent subgroup analysis revealed that the association between resting heart rate and plasma NT-proBNP was strengthened in subjects over 60 years old (partial correlation coefficient 1.28; 95% confidence interval, 0.49–2.36; P=0.031; while the relativity between resting heart rate and plasma NT-proBNP was not emerged in the younger subgroup (<60 years old.Conclusions: Resting heart rate was associated with plasma NT-proBNP in the elderly, which indicated a relationship between resting heart rate and cardiac function damage. Keywords: resting heart rate, N-terminal pro-brain natriuretic peptide, epidemiology, cardiac function, relationship

Cao R

2014-12-01

199

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  

Energy Technology Data Exchange (ETDEWEB)

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

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

2008-04-15

200

Autonomic dysfunction in HIV patients on antiretroviral therapy: studies of heart rate variability.  

DEFF Research Database (Denmark)

BACKGROUND: The presence of autonomic dysfunction in HIV patients is largely unknown. Early studies found autonomic dysfunction in patients with AIDS. Introduction of highly active antiretroviral combination therapy (ART) has dramatically changed the course of the disease and improved prognosis and decreased morbidity. At present it is not known whether introduction of ART also has decreased autonomic dysfunction. AIM: To evaluate whether autonomic dysfunction is present in an ART-treated HIV population. METHODS: HIV patients receiving ART for at least 3 years (n = 16) and an age-matched control group of healthy volunteers (n = 12) were included. All were non-smokers, non-diabetic and had never received medication for dyslipidaemia or hypertension. Following a 10 min resting period a 5 min ECG recording was performed. Heart rate variability (HRV) analysis was performed in accordance with current guidelines and data reported as median (interquartile range). RESULTS: The resting heart rate was higher in HIV patients compared with controls [69 (62-74) versus 57 (52-60); P<0.001]. Total HRV measured as standard deviation of normal-to-normal (SONN) was lower in the HIV group compared with the controls [36 (25-55) versus 74 (57-84) ms; P<0.01] as was parasympathetic activity measured as square root of the mean squared difference of successive normal-to-normal intervals (RMSSD) [22 (9-30) versus 35 (24-62) ms; P<0.05]. Low frequency power was lower in the HIV group compared with the control group [294 (161-602) versus 946 (711-1668) ms(2); P<0.01]. High frequency power as well as systolic and diastolic blood pressure did not differ between the groups. CONCLUSIONS: The HIV patients in ART have increased resting heart rate and decreased short-term heart rate variability indicating parasympathetic dysfunction.

Lebech, Anne-Mette; Kristoffersen, Ulrik Sloth

2007-01-01

201

Can a first-order exponential decay model fit heart rate recovery after resistance exercise?  

Science.gov (United States)

The time-constant of postexercise heart rate recovery (HRR? ) obtained by fitting heart rate decay curve by a first-order exponential fitting has being used to assess cardiac autonomic recovery after endurance exercise. The feasibility of this model was not tested after resistance exercise (RE). The aim of this study was to test the goodness of fit of the first-order exponential decay model to fit heart rate recovery (HRR) after RE. Ten healthy subjects participated in the study. The experimental sessions occurred in two separated days and consisted of performance of 1 set of 10 repetitions at 50% or 80% of the load achieved on the one-repetition maximum test [low-intensity (LI) and high-intensity (HI) sessions, respectively]. Heart rate (HR) was continuously registered before and during exercise and also for 10 min of recovery. A monoexponential equation was used to fit the HRR curve during the postexercise period using different time windows (i.e. 30, 60, 90, … 600 s). For each time window, (i) HRR? was calculated and (ii) variation of HR explained by the model (R(2) goodness of fit index) was assessed. The HRR? showed stabilization from 360 and 420 s on LI and HI, respectively. Acceptable R(2) values were observed from the 360 s on LI (R(2)  > 0·65) and at all tested time windows on HI (R(2)  > 0·75). In conclusion, this study showed that using a minimum length of monitoring (~420 s) HRR after RE can be adequately modelled by a first-order exponential fitting. PMID:24494748

Bartels-Ferreira, Rhenan; de Sousa, Élder D; Trevizani, Gabriela A; Silva, Lilian P; Nakamura, Fábio Y; Forjaz, Cláudia L M; Lima, Jorge Roberto P; Peçanha, Tiago

2015-03-01

202

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

203

Wearable depression monitoring system with heart-rate variability.  

Science.gov (United States)

A wearable depression monitoring system is proposed with an application-specific system-on-chip (SoC) solution. The SoC is designed to accelerate the filtering and feature extraction of heart-rate variability (HRV) from the electrocardiogram (ECG). Thanks to the SoC solution and planar-fashionable circuit board (P-FCB), the monitoring system becomes a low-power wearable system. Its dimension is 14cm × 7cm with 5mm thickness covering the chest band for convenient usage. In addition, with 3.7V 500mAh battery, its lifetime is at least 10 hours. For user's convenience, the system is interfacing to smart phones through Bluetooth communication. With the features of the HRV and Beck depression inventory (BDI), the smart phone application trains and classifies the user's depression scale with 71% of accuracy. PMID:25570021

Roh, Taehwan; Sunjoo Hong; Hoi-Jun Yoo

2014-08-01

204

Extraction of Heart Rate Variability from Smartphone Photoplethysmograms  

Science.gov (United States)

Heart rate variability (HRV) is a useful clinical tool for autonomic function assessment and cardiovascular diseases diagnosis. It is traditionally calculated from a dedicated medical electrocardiograph (ECG). In this paper, we demonstrate that HRV can also be extracted from photoplethysmograms (PPG) obtained by the camera of a smartphone. Sixteen HRV parameters, including time-domain, frequency-domain, and nonlinear parameters, were calculated from PPG captured by a smartphone for 30 healthy subjects and were compared with those derived from ECG. The statistical results showed that 14 parameters (AVNN, SDNN, CV, RMSSD, SDSD, TP, VLF, LF, HF, LF/HF, nLF, nHF, SD1, and SD2) from PPG were highly correlated (r > 0.7, P HRV measurement. PMID:25685174

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

2015-01-01

205

[Analysis of heart rate variability : Mathematical description and practical application].  

Science.gov (United States)

The analysis of heart rate variability (HRV) has recently become established as a non-invasive measurement for estimation of demands on the cardiovascular system. The HRV reflects the interaction of the sympathetic and parasympathetic nervous systems and allows the influence of the autonomic nervous system on the regulation of the cardiovascular system to be mathematically described. This review explicates the analysis method of HRV for time, frequency and non-linear methods as well as the range of parameters and the demand on acquisition time. The necessity and possibilities of artefact correction and advice for the selection of a reasonable acquisition period are discussed and standard values for selected HRV parameters are presented. PMID:25298003

Sammito, S; Böckelmann, I

2015-03-01

206

Heart Rate Variability Analysis Using Threshold of Wavelet Package Coefficients  

Directory of Open Access Journals (Sweden)

Full Text Available 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.

G. Kheder

2009-11-01

207

The blood pressure and heart rate chronome of centenarians.  

Science.gov (United States)

Rhythm characteristics of blood pressure (BP) and heart rate (Hr) of 11 healthy centenarians and 66 medical students are described. Each subject ambulatorily monitored measured BP and HR around the clock at 15-min intervals for 48 hours. Least-squares spectra were obtained by the fit of cosine curves (cosinor) and compared between the two populations. Confounding by geographic differences seems to be ruled out by comparisons with results from international data bases. A shift in prominence from the circadian domain to higher frequency harmonics was found for the BP but not for the HR of centenarians. In clinically mostly healthy centenarians, markers of primary aging may consist of a relatively low circadian BP and HR amplitude and a tendency toward internal and external desynchronization. Whether these chronobiologic changes with age are desirable, indifferent or undesirable can now be elucidated by outcome studies, in the light of the reference standards provided herein. PMID:1815852

Ikonomov, O; Stoynev, G; Cornélissen, G; Stoynev, A; Hillman, D; Madjirova, N; Kane, R; Halberg, F

1991-01-01

208

Emergence of dynamical complexity related to human heart rate variability  

Science.gov (United States)

We apply the refined composite multiscale entropy (MSE) method to a one-dimensional directed small-world network composed of nodes whose states are binary and whose dynamics obey the majority rule. We find that the resulting fluctuating signal becomes dynamically complex. This dynamical complexity is caused (i) by the presence of both short-range connections and long-range shortcuts and (ii) by how well the system can adapt to the noisy environment. By tuning the adaptability of the environment and the long-range shortcuts we can increase or decrease the dynamical complexity, thereby modeling trends found in the MSE of a healthy human heart rate in different physiological states. When the shortcut and adaptability values increase, the complexity in the system dynamics becomes uncorrelated.

Chang, Mei-Chu; Peng, C.-K.; Stanley, H. Eugene

2014-12-01

209

Associations between the cortisol awakening response and heart rate variability.  

Science.gov (United States)

The process of morning awakening is associated with a marked increase in cortisol secretion, the cortisol awakening response (CAR), as well as with a burst in cardiovascular (CV) activation. Whilst the CAR is largely driven by awakening-induced activation of hypothalamic-pituitary-adrenal axis, it is fine-tuned by direct sympathetic input to the adrenal gland. In parallel, awakening-induced activation of the CV system is associated with a shift towards dominance of the sympathetic branch of the autonomic nervous system. Moreover, the CAR, in common with trait-like heart rate variability (HRV), is widely reported to be associated with psychosocial variables and health outcomes. These commonalities led us to examine associations between the CAR and both concurrent awakening-induced changes and trait-like estimates in cardiovascular activity (heart rate (HR) and HRV). Self-report measures of difficulties in emotion regulation and chronic stress were also obtained. Forty-three healthy participants (mean age: 23 years) were examined on two consecutive weekdays. On both days, heart interbeat interval (IBI) data was obtained from sedentary laboratory recordings as well as from recordings over the peri-awakening period. Salivary free cortisol concentrations were determined on awakening and 15, 30, and 45min post-awakening on both study days. Data from a minimum of 36 participants were available for individual analyses. Results revealed significant awakening-induced changes in cortisol, HR and HRV measures; however, no associations were found between the simultaneous post-awakening changes of these variables. Similarly, awakening-induced changes in cortisol, HR and HRV measures were not significantly associated with perceived stress or measures of emotion regulation. However, the CAR was found to be significantly positively correlated with steady state measures of HR and negatively correlated with steady state measures of HRV, as determined during the laboratory sessions and the peri-awakening periods. This cross-sectional study indicates that, despite consistent associations between the CAR and indices of trait-like cardiovascular activity, the CAR is not related to concurrent changes of cardiac autonomic activation following awakening. PMID:20732747

Stalder, Tobias; Evans, Phil; Hucklebridge, Frank; Clow, Angela

2011-05-01

210

State level correlations between high heart attack and stroke symptomology knowledge scores and CVD risk factors and mortality rates  

Directory of Open Access Journals (Sweden)

Full Text Available Introduction: In 2008, cardiovascular disease (CVD accounted for one in three deaths in the United States. Epidemiological analyses suggest that two or more risk factors are the indicator of high risk and/or poor CVD outcomes. Knowledge of heart attack and stroke symptomology has been the focus of much research based on the assumption that accurate identification of an event is critical to reducing time to treatment. There is a paucity of research showing a clear association between knowledge of heart attack and stroke symptomology, risk factors, and mortality rates. In this study, we hypothesized that high stroke and heart attack symptomology knowledge scores would correspond to lower stroke or CVD mortality rankings as well as to a lower prevalence of two or more CVD risk factors. Methods: State was the unit of analysis used to examine data from two different sources and combined into a customized database. The first source was a multiyear Behavioral Risk Factor Surveillance Survey (BRFSS heart attack and stroke symptom knowledge module database. CVD and stroke mortality data used came from the American Heart Association’s (AHA 2012 Heart Disease and Stroke Statistics Update. Spearman’s Rho was the test statistic. Results: A moderate negative correlation was found between high heart attack and stroke symptom knowledge scores and the percentage of adults with two or more CVD or stroke risk factors. Likewise, a similar correlation resulted from the two variables, high heart attack and stroke symptoms knowledge score and CVD mortality rank. Conclusions: This study demonstrated a significant relationship between high heart attack and stroke symptom knowledge and lower CVD mortality rates and lower prevalence of two or more CVD risk factors at the state level. Our findings suggest that it is important to continue education efforts regarding heart attack and stroke symptom knowledge. Pharmacists are one group of health care providers who could enhance the needed public health education efforts.

Mary Nawal Lutfiyya

2013-09-01

211

Changes in heart rate of pitchers during semi-hard baseball practices and matches.  

Science.gov (United States)

High heart rate during competition is a response to both psychological and physiological stress, making it difficult to examine psychological stress in sport. The validity of a new method to extract psychological stress by subtracting heart rate during practice from that of competition was evaluated. The method was used in actual competition for eight pitchers. Most participants showed a "coasting phase," "increment phase," and "descent phase" for heart rate time-series data under both conditions. Heart rate in competitions was higher than during practice, and heart rate in both conditions showed a high correlation. Heart rate changes were significantly higher in situations in which two or three balls had already been thrown compared to zero balls thrown. Thus, psychological stress can be examined in various competition conditions using this method. PMID:25486047

Hashimoto, Yasuhiro; Inomata, Kimihiro

2014-12-01

212

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

213

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

Science.gov (United States)

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

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

2004-08-01

214

Simple and Cost-effective Heart Rate Meter Using PIC Microcontroller  

Directory of Open Access Journals (Sweden)

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

Souvik Das

2014-04-01

215

Effect of Supervised Integrated Exercise on Deep Breathing- Heart Rate Variability in Male Hypertensive Patients  

OpenAIRE

The aim of the study was to evaluate if prolonged supervised integrated exercise in male hypertensive patients reverses the deterioration of heart rate variability. Sixty six male hypertensive patients were divided into exercise (n = 30) and non-exercise groups (n = 36). Exercise group patients underwent a supervised integrated exercise program for one-year. Time domain analysis of heart rate variability was performed from electrocardiogram during deep breathing. Heart rate variability ...

Niranjan, M.; Nagaraja, H. S.; Anupama, B. K.; Bhagyalakshmi, N.; Bhat, R.; Prabha, A.

2008-01-01

216

Exercise heart rates at different serum digoxin concentrations in patients with atrial fibrillation.  

OpenAIRE

Heart rate at rest and during increasing workloads was measured in a double blind study of 12 patients with chronic atrial fibrillation when serum concentrations of digoxin were nil and at low and high therapeutic values. Twelve normal subjects were studied for comparison. The heart rate at all levels of exercise in most patients with atrial fibrillation was not adequately controlled by any serum digoxin concentration tested despite a reduction in heart rate with increasing serum digoxin conc...

Beasley, R.; Smith, D. A.; Mchaffie, D. J.

1985-01-01

217

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

OpenAIRE

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

218

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

OpenAIRE

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

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

2000-01-01

219

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

OpenAIRE

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 ...

SebastianWallot; RIccardoFusaroli

2013-01-01

220

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

OpenAIRE

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...

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

2011-01-01

221

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

OpenAIRE

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

222

Multi-slice spiral CT coronary angiography: influence of heart rate and reconstruction window on image quality  

International Nuclear Information System (INIS)

Objective: To evaluate the influence of heart rate and reconstruction window on image quality of multi-slice spiral CT coronary angiography. Methods: Retrospectively ECG-gated MSCT coronary angiography were performed in 80 healthy cases. Results: Four coronary (RCA, LM, LAD, LCX) segments were analyzed in each patient with regard to image quality. 82.1% (46/56) of the coronary segments were sufficient for analysis in patients with heart rate ?60 bpm, 63.4% (104/164) with 61-70 bpm, 41.2%(28/68) with 71-80 bpm, and 31.2%(10/32) with>80 bpm, respectively. The left anterior descending artery, left circumflex artery, and the right coronary artery were best visualized when the reconstruction window was 60%-70%, 50%-60%, and 50%-70%, respectively. Conclusion: Image quality of MSCT coronary angiography is highly dependent on heart rate and reconstruction window

223

Conditional mutual information-based feature selection for congestive heart failure recognition using heart rate variability.  

Science.gov (United States)

Feature selection plays an important role in pattern recognition systems. In this study, we explored the problem of selecting effective heart rate variability (HRV) features for recognizing congestive heart failure (CHF) based on mutual information (MI). The MI-based greedy feature selection approach proposed by Battiti was adopted in the study. The mutual information conditioned by the first-selected feature was used as a criterion for feature selection. The uniform distribution assumption was used to reduce the computational load. And, a logarithmic exponent weighting was added to model the relative importance of the MI with respect to the number of the already-selected features. The CHF recognition system contained a feature extractor that generated four categories, totally 50, features from the input HRV sequences. The proposed feature selector, termed UCMIFS, proceeded to select the most effective features for the succeeding support vector machine (SVM) classifier. Prior to feature selection, the 50 features produced a high accuracy of 96.38%, which confirmed the representativeness of the original feature set. The performance of the UCMIFS selector was demonstrated to be superior to the other MI-based feature selectors including MIFS-U, CMIFS, and mRMR. When compared to the other outstanding selectors published in the literature, the proposed UCMIFS outperformed them with as high as 97.59% accuracy in recognizing CHF using only 15 features. The results demonstrated the advantage of using the recruited features in characterizing HRV sequences for CHF recognition. The UCMIFS selector further improved the efficiency of the recognition system with substantially lowered feature dimensions and elevated recognition rate. PMID:22261219

Yu, Sung-Nien; Lee, Ming-Yuan

2012-10-01

224

A novel technique for fetal heart rate estimation from Doppler ultrasound signal  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background The currently used fetal monitoring instrumentation that is based on Doppler ultrasound technique provides the fetal heart rate (FHR signal with limited accuracy. It is particularly noticeable as significant decrease of clinically important feature - the variability of FHR signal. The aim of our work was to develop a novel efficient technique for processing of the ultrasound signal, which could estimate the cardiac cycle duration with accuracy comparable to a direct electrocardiography. Methods We have proposed a new technique which provides the true beat-to-beat values of the FHR signal through multiple measurement of a given cardiac cycle in the ultrasound signal. The method consists in three steps: the dynamic adjustment of autocorrelation window, the adaptive autocorrelation peak detection and determination of beat-to-beat intervals. The estimated fetal heart rate values and calculated indices describing variability of FHR, were compared to the reference data obtained from the direct fetal electrocardiogram, as well as to another method for FHR estimation. Results The results revealed that our method increases the accuracy in comparison to currently used fetal monitoring instrumentation, and thus enables to calculate reliable parameters describing the variability of FHR. Relating these results to the other method for FHR estimation we showed that in our approach a much lower number of measured cardiac cycles was rejected as being invalid. Conclusions The proposed method for fetal heart rate determination on a beat-to-beat basis offers a high accuracy of the heart interval measurement enabling reliable quantitative assessment of the FHR variability, at the same time reducing the number of invalid cardiac cycle measurements.

Jezewski Janusz

2011-10-01

225

Aerobic Exercise during Pregnancy and Presence of Fetal-Maternal Heart Rate Synchronization  

OpenAIRE

It has been shown that short-term direct interaction between maternal and fetal heart rates may take place and that this interaction is affected by the rate of maternal respiration. The aim of this study was to determine the effect of maternal aerobic exercise during pregnancy on the occurrence of fetal-maternal heart rate synchronization.

Leeuwen, Peter; Gustafson, Kathleen M.; Cysarz, Dirk; Geue, Daniel; May, Linda E.; Gro?nemeyer, Dietrich

2014-01-01

226

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

CERN Document Server

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

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

2015-01-01

227

Autonomic cardiac control in patients with epilepsy : spectral analysis of heart rate variability  

OpenAIRE

The heart is affected by the central nervous system via sympathetic and para-sympathetic efferents from autonomic centres in the brain stem. By assessing the beat to beat variation of the RR-intervals of the heart, i.e. the heart rate variability (HRV) it is possible to separately analyse sympathetic and parasympathetic effects on the heart. With spectral analysis of HRV the variability is separated into different bands, a high frequency band (HF) reflecting mainly parasympa...

Persson, Ha?kan

2006-01-01

228

A Role for BK Channels in Heart Rate Regulation in Rodents  

OpenAIRE

The heart generates and propagates action potentials through synchronized activation of ion channels allowing inward Na+ and Ca2+ and outward K+ currents. There are a number of K+ channel types expressed in the heart that play key roles in regulating the cardiac cycle. Large conductance calcium-activated potassium (BK) ion channels are not thought to be directly involved in heart function. Here we present evidence that heart rate can be significantly reduced by inhibiting the activity of BK c...

Imlach, Wendy L.; Finch, Sarah C.; Miller, John H.; Meredith, Andrea L.; Dalziel, Julie E.

2010-01-01

229

Decreased Variability of the 6-Minute Walk Test by Heart Rate Correction in Patients with Neuromuscular Disease  

DEFF Research Database (Denmark)

OBJECTIVE: The 6-minute walk test is widely used to assess functional status in neurological disorders. However, the test is subject to great inter-test variability due to fluctuating motivation, fatigue and learning effects. We investigated whether inter-test variability of the 6MWT can be reduced by heart rate correction. METHODS: Sixteen patients with neuromuscular diseases, including Facioscapulohumeral muscular dystrophy, Limb-girdle muscular dystrophy, Charcot-Marie-Tooths, Dystrophia Myotonica and Congenital Myopathy and 12 healthy subjects were studied. Patients were excluded if they had cardiac arrhythmias, if they received drug treatment for hypertension or any other medical conditions that could interfere with the interpretation of the heart rate and walking capability. All completed three 6-minute walk tests on three different test-days. Heart rate was measured continuously. RESULTS: Successive standard 6-minute walk tests showed considerable learning effects between Tests 1 and 2 (4.9%; P = 0.026), and Tests 2 and 3 (4.5%; P = 0.020) in patients. The same was seen in controls between Tests 1 and 2 (8.1%; P = 0.039)). Heart rate correction abolished this learning effect. CONCLUSION: A modified 6-minute walk test, by correcting walking distance with average heart rate during walking, decreases the variability among repeated 6-minute walk tests, and should be considered as an alternative outcome measure to the standard 6-minute walk test in future clinical follow-up and treatment trials.

Prahm, Kira Philipsen; Witting, Nanna

2014-01-01

230

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)

231

Relationship of 24-hour ambulatory blood pressure and heart rate with markers of hepatic function in cirrhotic patients  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background There is evidence that in cirrhotic patients, certain hemodynamic parameters, such as blood pressure and heart rate, are related to the severity of liver disease. This study investigated whether non-invasive 24-hour ambulatory blood pressure and heart rate are more closely associated with markers of liver disease severity than conventional office measurements. Methods Ambulatory patients with cirrhosis underwent office blood pressure and heart rate measurements, 24-hour ambulatory blood pressure monitoring and blood laboratory tests. Results Fifty-one patients (32 men, mean age 57.4 ± 11.3 years completed the study. Twenty six patients had compensated liver cirrhosis (group A and 25 patients had more advanced liver disease (group B. Group A and B patients differed significantly both in ambulatory asleep diastolic blood pressure (p Conclusions Heart rate seems to be a more reliable marker of ongoing liver dysfunction than blood pressure. Evaluation of blood pressure and heart rate with 24-hour ambulatory measurement does not seem to offer more information than conventional office measurements.

Stergiou George S

2010-12-01

232

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

Science.gov (United States)

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

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

1991-01-01

233

The compliance of the porcine pulmonary artery depends on pressure and heart rate.  

Science.gov (United States)

1. The influence of mean pulmonary arterial pressure (mean Ppa) on dynamic (Cd) and pseudo-static compliance (Cps) of the pulmonary artery was studied at a constant and a changing heart rate. Cd is the change in cross-sectional area (CSA) relative to the change in Ppa throughout a heart cycle. Cps is the change in mean CSA relative to the change in mean Ppa. If Cd is known, pulmonary blood flow can be computed from the Ppa using a windkessel model. We investigated whether Cps can be interchanged with Cd. 2. In nine anaesthetized pigs, we determined the mean CSA and Cd of the pulmonary artery at various Ppa levels, ranging from approximately 30 to 10 mmHg, established by bleeding. Two series of measurements were carried out, one series at a spontaneously changing heart rate (n = 9) and one series at a constant heart rate (n = 6). To determine CSA a conductance method was used. 3. Cps depended on pressure. The mean CSA versus mean Ppa curves were sigmoid and steepest in the series with the increasing heart rate (established by bleeding). The CSA versus Ppa loop during a heart cycle, giving Cd, was approximately linear and almost closed. The Cd versus mean Ppa relationship was bell shaped. Its width was smaller if the heart rate increased during the series of measurements. The pressure, where Cd was maximum, was higher at higher heart rates. Furthermore, the maximum Cd was not affected by the heart rate. 4. Because the pulmonary artery constricts with increasing heart rate, Cps will be overestimated during procedures where heart rate increases. Cd should be determined on a beat-to-beat basis to calculate flow because it changes with mean pulmonary arterial pressure and heart rate. PMID:9769432

Kornet, L; Jansen, J R; Nijenhuis, F C; Langewouters, G J; Versprille, A

1998-11-01

234

Accuracy of Borg's ratings of perceived exertion in the prediction of heart rates during pregnancy.  

OpenAIRE

When using Borg's 6-20 scale during pregnancy, ratings of perceived exertion (RPE) did not significantly correlate with exercise heart rates (HR) (P greater than 0.05). The HR predicted from RPE significantly (P less than 0.05) underestimated the exercise HR in the second trimester during walking (Group 1: mean difference 16 beats min-1, n = 11), aerobics classes (Group 4: mean 15 beats min-1, n = 48) and circuit training (Group 3: mean 18 beats min-1, n = 24); and in the third trimester duri...

O Neill, M. E.; Cooper, K. A.; Mills, C. M.; Boyce, E. S.; Hunyor, S. N.

1992-01-01

235

Heart rate variability in children with cyanotic and acyanotic congenital heart disease: analysis by spectral and non linear indices.  

Science.gov (United States)

Congenital heart defects affect the efficiency and functionality of the heart, and autonomic control of heart rate and of circulation can display a pathologic behavior in order to compensate for the hemodynamic alterations due to disease. While previous works have investigated heart rate variability (HRV) in specific pathologies, e.g. tetralogy of Fallot, the goal of this study was to assess HRV in children with a congenital heart malformation taking into account the effects of cyanotic and acyanotic defects, and comparing pathologic children with age matched controls. HRV, approximate entropy (ApEn) and sample entropy (SampEn) were calculated to discuss the dynamics and complexity of heart rhythms, and to evaluate the potential impairment of control mechanisms. Analyses showed that low frequency (LF) power and total power of HRV were significantly higher in children with a condition than in healthy controls, independently of cyanosis. Non linear indices were also significantly higher in pathologic subjects. Significant differences in LF, total power, ApEn and SampEn were found among cyanotic, acyanotic and healthy children. These results suggested that children with a congenital heart condition display more complex HRV and sympathetic overactivity, which may be aimed at compensating for hemodynamic alterations. Further studies should investigate whether corrective surgery and rehabilitation can improve HRV and restore its physiological features. PMID:23366851

Aletti, Federico; Ferrario, Manuela; de Jesus, Taiana Bertacini Almas; Stirbulov, Roberto; Silva, Audrey Borghi; Cerutti, Sergio; Sampaio, Luciana Malosa

2012-01-01

236

Influence of physical exercise on serum digoxin concentration and heart rate in patients with atrial fibrillation.  

OpenAIRE

Heart rate and serum digoxin concentration in eight patients with atrial fibrillation were studied at rest and during exercise when initial serum digoxin concentrations were zero and at low and high therapeutic values. Eight patients with ischemic heart disease and in sinus rhythm were studied for comparison. Though the serum digoxin concentration decreased significantly during exercise, the absolute reduction in heart rate was the same at rest and during exercise in patients with atrial fibr...

Bøtker, H. E.; Toft, P.; Klitgaard, N. A.; Simonsen, E. E.

1991-01-01

237

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

Directory of Open Access Journals (Sweden)

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

Rousse Maria G

2011-04-01

238

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

239

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

240

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

241

Extraction of heart rate variability from smartphone photoplethysmograms.  

Science.gov (United States)

Heart rate variability (HRV) is a useful clinical tool for autonomic function assessment and cardiovascular diseases diagnosis. It is traditionally calculated from a dedicated medical electrocardiograph (ECG). In this paper, we demonstrate that HRV can also be extracted from photoplethysmograms (PPG) obtained by the camera of a smartphone. Sixteen HRV parameters, including time-domain, frequency-domain, and nonlinear parameters, were calculated from PPG captured by a smartphone for 30 healthy subjects and were compared with those derived from ECG. The statistical results showed that 14 parameters (AVNN, SDNN, CV, RMSSD, SDSD, TP, VLF, LF, HF, LF/HF, nLF, nHF, SD1, and SD2) from PPG were highly correlated (r > 0.7, P < 0.001) with those from ECG, and 7 parameters (AVNN, TP, VLF, LF, HF, nLF, and nHF) from PPG were in good agreement with those from ECG within the acceptable limits. In addition, five different algorithms to detect the characteristic points of PPG wave were also investigated: peak point (PP), valley point (VP), maximum first derivative (M1D), maximum second derivative (M2D), and tangent intersection (TI). The results showed that M2D and TI algorithms had the best performance. These results suggest that the smartphone might be used for HRV measurement. PMID:25685174

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

2015-01-01

242

Learning dependencies among fetal heart rate features using Bayesian networks.  

Science.gov (United States)

We present preliminary results on the use of Bayesian-network (BN) structure learning algorithms for deciphering dependencies from amongst different fetal heart rate (FHR) features collected from a real database. We used a greedy search-and-score procedure known as the K2 algorithm for the estimation of the BN structure. The database consists of a collection of discrete-valued features quantifying presence of morphological changes as prescribed by expert guidelines (updated by the National Institute of Child Health and Human Development (NICHD)) and implemented as rule-based programs. We compare the results of structure learning to the expert-guided structure and use decision functions for classification using posterior probabilities. It was found that the BN estimated from structure learning algorithms had comparable classification performance, but fewer edges, leading to more efficient characterization of conditional probability tables (CPD's). Moreover, structure learning algorithms offer a method of learning novel correlations between FHR features that may be exploited for automatic categorization. PMID:23367346

Dash, Shishir; Quirk, J Gerald; Djuri?, Petar M

2012-01-01

243

Increased heart rate and atherosclerosis: Potential implications of ivabradine therapy  

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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

244

The relationship between working memory, reinvestment, and heart rate variability.  

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There is growing evidence illustrating the negative aspects of reinvestment on everyday life, however its underlying mechanisms remain unclear. The main aim of this study was to empirically clarify the relationship between reinvestment and working memory (WM). A secondary aim was to investigate the contribution of high-frequency heart rate variability (HF-HRV) to WM. Sixty-two participants took part in a within-subject design in which we measured their WM capacity in a low-pressure and a high-pressure condition while their HF-HRV was measured. In addition, they had to fill out scales assessing their dispositional reinvestment. Results showed that the correlation between reinvestment and WM is negative, exists only in the high-pressure condition, and is specific to the decision component of reinvestment and not the movement component. Moreover, a hierarchical regression analysis revealed that under high pressure resting HF-HRV predicted WM performance above DSRS, whereas DSRS did not predict WM performance above resting HF-HRV. PMID:25449388

Laborde, Sylvain; Furley, Philip; Schempp, Caroline

2015-02-01

245

Gene expression profile of increased heart rate in shensongyangxin-treated bradycardia rabbits.  

Science.gov (United States)

Aims. The present study tries to investigate the gene expression profile of bradycardia rabbits' hearts after SSYX (SSYX, a traditional Chinese medicine) treatment. Methods. Eighteen adult rabbits were randomly assigned in three groups: sham, model, and SSYX treatment groups. Heart rate was recorded in rabbits and total RNA was isolated from hearts. Gene expression profiling was conducted and quantitative real-time reverse transcription-polymerase chain reaction (RT-PCR) was performed to confirm the gene expression results. Patch clamp using human induced pluripotent stem cell-derived cardiomyocytes was applied to record the calcium current in the presence of SSYX. Results. The mean RR interval reduced after six weeks due to the injury of the sinoatrial node in the model group. This effect was partially reversed by 4-week SSYX treatment. cDNA microarray demonstrated that genes related with pacemaker current, calcium ion homeostasis, and signaling were altered by SSYX treatment. Results from patch clamp demonstrated that SSYX reduced the calcium current which is consistent with gene expression results. Conclusion. The present study shows mRNA remodeling of bradycardia and demonstrates that SSYX is effective in treating bradycardia by reversing altered gene expression in bradycardia models. Reduced calcium current by SSYX also confirmed the gene expression results. PMID:25525447

Liu, Zhouying; Huang, Jian; Hu, Roumu; Huo, Youping; Gong, Jing; Zhang, Yinhui; Wei, Cong; Pu, Jielin

2014-01-01

246

SKIPPING BREAKFAST: GENDER EFFECTS ON RESTING HEART RATE MEASURES IN PREADOLESCENTS  

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The cardiovascular response in children to morning nutrition has received little attention, and associated gender-related effects are virtually uninvestigated. This study evaluated resting heart-rate (HR) and heart-rate variability (HRV) in preadolescents after overnight fasting and again after eati...

247

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

OpenAIRE

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

Shoira Agzamova

2010-01-01

248

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

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

Shoira Agzamova

2010-12-01

249

Heart Rate and Treatment Effect in Children with Disruptive Behavior Disorders  

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Objective: To examine whether children with disruptive behavior disorders (DBDs; hyperkinetic conduct disorder, conduct disorder, hyperkinetic disorder) characterized by low heart rate profit less from an intensive cognitive behavioral intervention aimed at reducing impulsive, oppositional and aggressive behavior problems. Method: Basal heart rate

Stadler, Christina; Grasmann, Dorte; Fegert, Jorg M.; Holtmann, Martin; Poustka, Fritz; Schmeck, Klaus

2008-01-01

250

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

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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

251

Electroencephalogram and Heart Rate Regulation to Familiar and Unfamiliar People in Children with Autism Spectrum Disorders  

Science.gov (United States)

Few studies have examined whether familiarity of partner affects social responses in children with autism. This study investigated heart rate regulation (respiratory sinus arrhythmia [RSA]: The myelinated vagus nerve's regulation of heart rate) and temporal-parietal electroencephalogram (EEG) activity while nineteen 8- to 12-year-old children with…

Van Hecke, Amy Vaughan; Lebow, Jocelyn; Bal, Elgiz; Lamb, Damon; Harden, Emily; Kramer, Alexis; Denver, John; Bazhenova, Olga; Porges, Stephen W.

2009-01-01

252

Heart Rates of Elementary Physical Education Students during the Dancing Classrooms Program  

Science.gov (United States)

We examined how different types of dance activities, along with their duration, influenced heart rate responses among fifth-grade physical education students (N = 96) who participated in the Dancing Classrooms program. Results indicated that the overall Dancing Classrooms program elicits a moderate cardiovascular heart rate response (M = 124.4…

Nelson, Larry; Evans, Melissa; Guess, Wendy; Morris, Mary; Olson, Terry; Buckwalter, John

2011-01-01

253

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

254

Introduction to Controversial Topics in Nonlinear Science: Is the Normal Heart Rate Chaotic?  

Science.gov (United States)

In June 2008, the editors of Chaos decided to institute a new section to appear from time to time that addresses timely and controversial topics related to nonlinear science. The first of these deals with the dynamical characterization of human heart rate variability. We asked authors to respond to the following questions: Is the normal heart rate chaotic? If the normal heart rate is not chaotic, is there some more appropriate term to characterize the fluctuations (e.g., scaling, fractal, multifractal)? How does the analysis of heart rate variability elucidate the underlying mechanisms controlling the heart rate? Do any analyses of heart rate variability provide clinical information that can be useful in medical assessment (e.g., in helping to assess the risk of sudden cardiac death)? If so, please indicate what additional clinical studies would be useful for measures of heart rate variability to be more broadly accepted by the medical community. In addition, as a challenge for analysis methods, PhysioNet [A. L. Goldberger et al., "PhysioBank, PhysioToolkit, and PhysioNet: Components of a new research resource for complex physiologic signals," Circulation 101, e215-e220 (2000)] provided data sets from 15 patients of whom five were normal, five had heart failure, and five had atrial fibrillation (http://www.physionet.org/challenge/chaos/). This introductory essay summarizes the main issues and introduces the essays that respond to these questions.

Glass, Leon

2009-06-01

255

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

DEFF Research Database (Denmark)

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

Hansen, Tine Willum; Thijs, Lutgarde

2008-01-01

256

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

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

Freitas Júnior Ismael F

2012-01-01

257

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

258

Assessment of baroreflex sensitivity from spontaneous oscillations of blood pressure and heart rate: proven clinical value?  

Science.gov (United States)

The baroreceptor-heart rate reflex (baroreflex sensitivity, BRS) is a key mechanism contributing to the neural regulation of the cardiovascular system. Several methods have been proposed so far to assess BRS by analyzing the spontaneous beat-to-beat fluctuations of arterial blood pressure and heart rate. These methods are inherently simple, non-invasive and low-cost. This study is an attempt to address the question of whether spontaneous baroreflex methods have proven to be of value in the clinical setting. In the first part of this article, we critically review most representative clinical studies using spontaneous BRS techniques either for risk stratification or treatment evaluation, these being major issues in the clinical management of the patients. In the second part, we address two important aspects of spontaneous BRS measurements: measurability and reliability. Estimation of BRS in the studies selected for the review was performed according to the sequence, transfer function, alpha-index and phase-rectified signal averaging method. Arterial blood pressure was recorded non-invasively during supine, short-term (<30?min) laboratory recordings. The conclusion from this review is that spontaneous BRS techniques have been shown to be of great value in clinical practice but further work is needed to confirm the validity of previous findings and to widen the field of clinical applications. Measurability and reliability can be a major issue in the measurement of spontaneous BRS, particularly in some patient populations like post-myocardial infarction and heart failure patents. Main causes of poor measurability are: non-sinus rhythm, a high rate of ectopic beats and the need for recorded time series of RR interval and arterial blood pressure to satisfy the constraints of the different BRS estimation algorithms. As for reliability, within-subject variability is rather high in the measurements of spontaneous BRS and, therefore, should be carefully taken into account when BRS measurements are used to detect treatment effects in individual patients. PMID:25798657

Pinna, Gian Domenico; Maestri, Roberto; La Rovere, Maria Teresa

2015-04-01

259

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

260

Cross-country skiing and postexercise heart-rate recovery.  

Science.gov (United States)

Postexercise heart-rate (HR) recovery (HRR) indices have been associated with running and cycling endurance-exercise performance. The current study was designed (1) to test whether such a relationship also exists in the case of cross-country skiing (XCS) and (2) to determine whether the magnitude of any such relationship is related to the intensity of exercise before obtaining HRR indices. Ten elite male cross-country skiers (mean ± SD; 28.2 ± 5.4 y, 181 ± 8 cm, 77.9 ± 9.4 kg, 69.5 ± 4.3 mL · min-1 · kg-1 maximal oxygen uptake [VO2max]) performed 2 sessions of roller-skiing on a treadmill: a 2 × 3-km time trial and the same 6-km at an imposed submaximal speed followed by a final 800-m time trial. VO2 and HR were monitored continuously, while HRR and blood lactate (BLa) were assessed during 2 min immediately after each 6-km and the 800-m time trial. The 6-km time-trial time was largely negatively correlated with VO2max and BLa. On the contrary, there was no clear correlation between the 800-m time-trial time and VO2, HR, or BLa. In addition, in no case was any clear correlation between any of the HRR indices and performance time or VO2max observed. These findings confirm that XCS performance is largely correlated with VO2max and the ability to tolerate high levels of BLa; however, postexercise HRR showed no clear association with performance. The homogeneity of the group of athletes involved and the contribution of the arms and upper body to the exercise preceding determination of HRR may explain this absence of a relationship. PMID:24806737

Mourot, Laurent; Fabre, Nicolas; Andersson, Erik; Willis, Sarah; Buchheit, Martin; Holmberg, Hans-Christer

2015-01-01

261

Estimating mental fatigue based on electroencephalogram and heart rate variability  

Science.gov (United States)

The effects of long term mental arithmetic task on psychology are investigated by subjective self-reporting measures and action performance test. Based on electroencephalogram (EEG) and heart rate variability (HRV), the impacts of prolonged cognitive activity on central nervous system and autonomic nervous system are observed and analyzed. Wavelet packet parameters of EEG and power spectral indices of HRV are combined to estimate the change of mental fatigue. Then wavelet packet parameters of EEG which change significantly are extracted as the features of brain activity in different mental fatigue state, support vector machine (SVM) algorithm is applied to differentiate two mental fatigue states. The experimental results show that long term mental arithmetic task induces the mental fatigue. The wavelet packet parameters of EEG and power spectral indices of HRV are strongly correlated with mental fatigue. The predominant activity of autonomic nervous system of subjects turns to the sympathetic activity from parasympathetic activity after the task. Moreover, the slow waves of EEG increase, the fast waves of EEG and the degree of disorder of brain decrease compared with the pre-task. The SVM algorithm can effectively differentiate two mental fatigue states, which achieves the maximum classification accuracy (91%). The SVM algorithm could be a promising tool for the evaluation of mental fatigue. Fatigue, especially mental fatigue, is a common phenomenon in modern life, is a persistent occupational hazard for professional. Mental fatigue is usually accompanied with a sense of weariness, reduced alertness, and reduced mental performance, which would lead the accidents in life, decrease productivity in workplace and harm the health. Therefore, the evaluation of mental fatigue is important for the occupational risk protection, productivity, and occupational health.

Zhang, Chong; Yu, Xiaolin

2010-01-01

262

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

OpenAIRE

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

263

Heart rate estimation from FBG sensors using cepstrum analysis and sensor fusion.  

Science.gov (United States)

This paper presents a method of estimating heart rate from arrays of fiber Bragg grating (FBG) sensors embedded in a mat. A cepstral domain signal analysis technique is proposed to characterize Ballistocardiogram (BCG) signals. With this technique, the average heart beat intervals can be estimated by detecting the dominant peaks in the cepstrum, and the signals of multiple sensors can be fused together to obtain higher signal to noise ratio than each individual sensor. Experiments were conducted with 10 human subjects lying on 2 different postures on a bed. The estimated heart rate from BCG was compared with heart rate ground truth from ECG, and the mean error of estimation obtained is below 1 beat per minute (BPM). The results show that the proposed fusion method can achieve promising heart rate measurement accuracy and robustness against various sensor contact conditions. PMID:25571206

Zhu, Yongwei; Fook, Victor Foo Siang; Jianzhong, Emily Hao; Maniyeri, Jayachandran; Guan, Cuntai; Zhang, Haihong; Jiliang, Eugene Phua; Biswas, Jit

2014-01-01

264

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

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

Ivana Antelmi

2008-06-01

265

Low metabolism and inactive lifestyle of a tropical rain forest bird investigated via heart-rate telemetry  

OpenAIRE

Birds in the lowland tropical rain forest are expected to have low energy turnover. Here, we used heart rate telemetry to estimate nighttime resting metabolic rate (RMR), daily energy expenditure (DEE), and locomotor activity of a small, long?lived tropical rain forest understory bird, the spotted antbird (Hylophylax naevioides). Heart rate was linearly related to oxygen consumption in respirometry measurements that encompassed 96% of heart rates measured in wild birds. Heart rates in the w...

Steiger, Silke S.; Kelley, J. Patrick; Cochran, William W.; Wikelski, Martin

2009-01-01

266

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

267

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

Directory of Open Access Journals (Sweden)

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

268

Does Acupuncture Reduce Stress Over Time? A Clinical Heart Rate Variability Study in Hypertensive Patients.  

Science.gov (United States)

Background: Heart rate variability (HRV), a noninvasive autonomic measure, has been applied to acupuncture interventions in controlled academic settings comparing points used, types of stimulation, or the HRV parameters measured. There is evidence that acupuncture decreases the stress response in both human and animal subjects, and can increase HRV in the short term (minutes to hours). Objectives: The goal of this study was to explore an array of HRV parameters during acupuncture sessions and over the course of treatment (weeks to months) in a series of patients being treated for hypertension. Materials and Methods: This was a retrospective, uncontrolled case study of patients presenting to a private acupuncture clinic. Patients received manual body acupuncture prescribed by the tenets of Traditional Chinese Medicine (TCM) and by published protocols for hypertension treatment. Heart rate was monitored during and after needle placement. The tracings were then analyzed with the Vivosense HRV analysis system. The main outcome measures were were patients' blood pressure measurements and low-frequency-to-high-frequency (LF/HF) ratio of HRV. Results: Patients tended to have an increase in their HRV during treatment, after needling, and, in some instances, an increase in HRV over weeks to months. Conclusions: Some patients' HRV increased over weeks to months during the course of acupuncture treatment for hypertension as evidenced by a decrease in their LF/HF ratio. This would indicate a relative decrease in their physiologic stress. PMID:25352944

Sparrow, Kristen; Golianu, Brenda

2014-10-01

269

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

Science.gov (United States)

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 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

270

Heart rate at 4 s after the onset of exercise in endurance-trained men.  

Science.gov (United States)

It has been suggested that the increase in heart rate (HR) at the onset of exercise is caused by vagal withdrawal. In fact, endurance runners show a lower HR in maximum aerobic tests. However, it is still unknown whether endurance runners have a lower HR at 4 s after the onset of exercise (4th-sec-HR). We sought to measure the HR at the onset of the 4 s exercise test (4-sET), clarifying its relationship to heart rate variability (HRV), spectral indices, and cardiac vagal index (CVI) in endurance runners (ER) and healthy untrained controls (CON). HR at 4th-sec-HR, CVI, and percent HR increase during exercise were analyzed in the 4-sET. High frequency spectrum (HF-nu), low frequency spectrum (LF-nu), and low frequency/high frequency band ratio (LF/HF) were analyzed from the HRV. ER showed a significantly higher HF, and both a lower LF and LF/HF ratio compared with the CON. ER presented a significantly lower 4th-sec-HR, although neither CVI nor HR increases during exercise were statistically different from the CON. In conclusion, ER presented a lower 4th-sec-HR secondary to increased vagal influence over the sinus node. CVI seems to be too weak to use for discriminating individuals with respect to the magnitude of HR vagal control. PMID:24886303

Zaniqueli, Divanei; Morra, Elis Aguiar; Dantas, Eduardo Miranda; Baldo, Marcelo Perim; Carletti, Luciana; Perez, Anselmo José; Rodrigues, Sérgio Lamêgo; Mill, José Geraldo

2014-06-01

271

Heart Rate Variability in Overweight Health Care Students: Correlation with Visceral Fat  

Science.gov (United States)

Background and Objectives: Increased sympathetic activity, decreased parasympathetic activity and sympathovagal imbalance (SVI) has been reported in obese individuals. However, the SVI and its association with visceral fat in overweight health care students have not been explored. Therefore, in the present study, we have assessed heart rate variability (HRV) and its association with visceral fat in overweight health care students. Materials and Methods: Frequency domain parameters of HRV, body fat distribution and baseline anthropometric parameters were recorded in the control (n=40) and overweight (n=40) individuals. Further, the association of visceral fat with HRV was analysed. Results: There was no significant difference in age and height of overweight group and control group (p = 0.732). The baseline heart rate and blood pressure (pHRV, LFnu and LF: HF were more in the overweight group (p<0.001). Further, HFnu was less in the overweight group (p<0.001). Conclusion: Sympathovagal imbalance due to increased sympathetic activity and its association with visceral fat was observed in overweight individuals. PMID:25737980

Krishna, Bandi Hari; N, Mallikarjuna Reddy

2015-01-01

272

The Forgotten Role of Central Volume in Low Frequency Oscillations of Heart Rate Variability  

Science.gov (United States)

The hypothesis that central volume plays a key role in the source of low frequency (LF) oscillations of heart rate variability (HRV) was tested in a population of end stage renal disease patients undergoing conventional hemodialysis (HD) treatment, and thus subject to large fluid shifts and sympathetic activation. Fluid overload (FO) in 58 chronic HD patients was assessed by whole body bioimpedance measurements before the midweek HD session. Heart Rate Variability (HRV) was measured using 24-hour Holter electrocardiogram recordings starting before the same HD treatment. Time domain and frequency domain analyses were performed on HRV signals. Patients were retrospectively classified in three groups according to tertiles of FO normalized to the extracellular water (FO/ECW%). These groups were also compared after stratification by diabetes mellitus. Patients with the low to medium hydration status before the treatment (i.e. 1st and 2nd FO/ECW% tertiles) showed a significant increase in LF power during last 30 min of HD compared to dialysis begin, while no significant change in LF power was seen in the third group (i.e. those with high pre-treatment hydration values). In conclusion, several mechanisms can generate LF oscillations in the cardiovascular system, including baroreflex feedback loops and central oscillators. However, the current results emphasize the role played by the central volume in determining the power of LF oscillations. PMID:25793464

Ferrario, Manuela; Moissl, Ulrich; Garzotto, Francesco; Cruz, Dinna N.; Tetta, Ciro; Signorini, Maria G.; Ronco, Claudio; Grassmann, Aileen; Cerutti, Sergio; Guzzetti, Stefano

2015-01-01

273

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

Directory of Open Access Journals (Sweden)

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

274

Heart rate variability analysis in sheep affected by transmissible spongiform encephalopathies  

Directory of Open Access Journals (Sweden)

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

275

Drawing Conclusions  

Science.gov (United States)

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

Michael P. Klentschy

2008-04-01

276

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

Science.gov (United States)

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

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

2014-05-01

277

Gene Expression Profile of Increased Heart Rate in Shensongyangxin-Treated Bradycardia Rabbits  

OpenAIRE

Aims. The present study tries to investigate the gene expression profile of bradycardia rabbits' hearts after SSYX (SSYX, a traditional Chinese medicine) treatment. Methods. Eighteen adult rabbits were randomly assigned in three groups: sham, model, and SSYX treatment groups. Heart rate was recorded in rabbits and total RNA was isolated from hearts. Gene expression profiling was conducted and quantitative real-time reverse transcription-polymerase chain reaction (RT-PCR) was performed to conf...

Liu, Zhouying; Huang, Jian; Hu, Roumu; Huo, Youping; Gong, Jing; Zhang, Yinhui; Wei, Cong; Pu, Jielin

2014-01-01

278

Heart rate regulation processed through wavelet analysis and change detection: some case studies.  

OpenAIRE

Heart rate variability (HRV) is an indicator of the regulation of the heart, see Task Force (Circulation 93(5):1043-1065, 1996). This study compares the regulation of the heart in two cases of healthy subjects within real life situations: Marathon runners and shift workers. After an update on the state of the art on HRV processing, we specify our probabilistic model: We choose modeling heartbeat series by locally stationary Gaussian process (Dahlhaus in Ann Stat 25, 1997). HRV is then process...

Khalfa, Nadia; Bertrand, Pierre; Boudet, Gil; Chamoux, Alain; Billat, Ve?ronique

2012-01-01

279

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

DEFF Research Database (Denmark)

The heart rate variability (HRV) is a commonly used method to quantify the sympathetic and the parasympathetic modulation of the heart rate. HRV is mainly conducted on electrocardiograms (ECG). However, the use of photoplethysmography (PPG) as a marker of the autonomic tone is emerging. In this study we investigated the feasibility of deriving pulse rate variability (PRV) using PPG signals recorded by a reflectance PPG sensor attached to the chest bone (sternum) and comparing it to HRV. The recordings were conducted on 9 healthy subjects being in a relaxed supine position and under forced respiration, where the subjects were asked to breathe following a visual scale with a rate of 27 breaths/min. HRV parameters such as the mean intervals (meanNN), the standard deviation of intervals (SDNN), the root mean square of difference of successive intervals (RMSSD), and the proportion of intervals differing more than 50 ms (pNN50) were calculated from the R peak-to-R peak (R-R) and pulse-to-pulse (P-P) intervals. In the frequency domain the low and high frequency ratio of the power spectral density (LF/HF) was also computed. The Pearson correlation coefficient showed significant correlation for all the parameters (r > 0:95 with p < 0:001) and the Bland-Altmann analysis showed close agreement between the two methods for all the parameters during resting and forced respiration condition. Thus, PRV analysis using sternal PPG can be an alternative to HRV analysis on healthy subjects at rest.

Chreiteh, Shadi; Belhage, Bo

2014-01-01

280

Heart Rate Analysis and Telemedicine: New Concepts & Maths  

Directory of Open Access Journals (Sweden)

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

281

Validity of a heart rate monitor during work in the laboratory and on the Space Shuttle  

Science.gov (United States)

Accurate heart rate measurement during work is required for many industrial hygiene and ergonomics situations. The purpose of this investigation was to determine the validity of heart rate measurements obtained by a simple, lightweight, commercially available wrist-worn heart rate monitor (HRM) during work (cycle exercise) sessions conducted in the laboratory and also during the particularly challenging work environment of space flight. Three different comparisons were made. The first compared HRM data to simultaneous electrocardiogram (ECG) recordings of varying heart rates that were generated by an ECG simulator. The second compared HRM data to ECG recordings collected during work sessions of 14 subjects in the laboratory. Finally, ECG downlink and HRM data were compared in four astronauts who performed cycle exercise during space flight. The data were analyzed using regression techniques. The results were that the HRM recorded virtually identical heart rates compared with ECG recordings for the data set generated by an ECG simulator. The regression equation for the relationship between ECG versus HRM heart rate data during work in the laboratory was: ECG HR = 0.99 x (HRM) + 0.82 (r2 = 0.99). Finally, the agreement between ECG downlink data and HRM data during space flight was also very high, with the regression equation being: Downlink ECG HR = 1.05 x (HRM) -5.71 (r2 = 0.99). The results of this study indicate that the HRM provides accurate data and may be used to reliably obtain valid data regarding heart rate responses during work.

Moore, A. D. Jr; Lee, S. M.; Greenisen, M. C.; Bishop, P.

1997-01-01

282

Heart rate reduction: a potential target for the treatment of myocardial ischaemia.  

Science.gov (United States)

Because most of myocardial perfusion takes place during diastole, reducing the heart rate is likely to have anti-ischaemic effects. The present paper reviews the role of heart rate in relation to coronary artery disease outcome, as well as ways to reduce heart rate in the clinical setting. Nonpharmacological intervention, and particularly exercise training, has a definite effect on both heart rate reduction and the prevention of myocardial ischaemia. The protective role of beta-blockers after acute myocardial infarction is amply documented; their anti-ischaemic efficacy appears to be attributable to their effect on heart rate, but also to their role in cardiac inotropism. Recently, the If (funny) current inhibitor ivabradine, which has a potent heart rate reduction effect without any haemodynamic effect has demonstrated anti-ischaemic efficacy in a randomised trial versus placebo, as well as in trials where it showed an effect similar to that of the conventional anti-ischaemic agents amlodipine and atenolol. In addition, such an agent, which does not influence myocardial contractility, might be particularly valuable in the setting of myocardial stunning or acute left ventricular failure at the acute stage of myocardial infarction. However, only future studies will determine whether isolated heart rate reduction will have the same protective efficacy as that of beta-blocking agents in secondary prevention after myocardial infarction. PMID:15648303

Danchin, Nicolas; Aly, Sidi

2004-01-01

283

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

284

[Interrelation between well-being of the mother and heart rate variability of her preterm infant].  

Science.gov (United States)

The relationship between mothers' well-being and the heart rate variability of their preterm babies was investigated. In order to study a possible influence of the mother's well-being on the calming quality of her voice and thereby on the heart rate variability of her preterm infant, maternal/paternal stress and competences as well as family functionality were assessed via respective questionnaires. (N = 30) Preterm babies at the postnatal age of approximately 4 weeks were acoustically stimulated with the voice of their own mother. Various heart rate variability measures (NN interval mean value, NN interval median, variance of NN intervals, standard deviation of NN intervals, pnn 6,25, RMSSD, SDSD and RSA) were recorded 15 minutes before, 15 minutes during and 15 minutes after the acoustic stimulation. Non-REM sleep sections of 2 minutes duration were matter of analyses. The correlations between the mothers' well-being and their babies' heart rate variability indicate a strong relationship. The correlations point out that a higher family functionality is associated with a higher heart rate variability of preterm babies. Contradictory to the expectations, higher burden and lower resources as well as lower competences of the mothers were associated with a higher heart rate variability of the preterm babies. Simultaneous real-time investigations of the mothers' and the babies' heart rate variability during a live mother-baby-interaction seems necessary to provide further explanations. PMID:18257477

Djordjevic, Dragana; Linderkamp, Otwin; Brüssau, Jürgen; Cierpka, Manfred

2007-01-01

285

The relationship between heart rate as an indicator of work hardness and results of dynamometry.  

Science.gov (United States)

Heart rate is associated with work hardness and increase linearly with its increasing. In the average of energy consumption, heart rate measurement is simple but non-accurate method for calculation of work hardness. Our purpose in this research was to evaluate the relationship between heart rate and dynamometry results with hypothesis of work hardness effectiveness on the human power. This study was conducted on 102 porcelain workers. Participants were selected randomly. The research tools include stethoscope, the dynamometer. Heart rate, and pinch, grip, and back-leg-chest force were measured and relationships between variables were analyzed with Pearson correlation test and independent T-test using Spss 16 software. The average heart rate of participants were 4.11 ± 1.79 with minimum 60 and maximum 120. The average force of pinch, grip, and back-leg-chest were 8.9 ± 3.20, 4.2 ± 4.5 and 9.36 ± 6.55, respectively. Work hardness for 3.86% of workers were light, 7.12% were moderate and 1% were heavy. Pinch, grip, and back-leg-chest force relation with heart rate were not significant (r=0.01, p=0.85), (r=-0.03, p=0.74), and (r=0.05, p= 0.59), respectively. There was no correlation between heart rate and work hardness. So we can't use the dynamometry results to determine of work hardness. PMID:22317650

Sadeghi, Nasrin; Tolide-ie, Hamidreza; Ghaderi, Fatemeh

2012-01-01

286

Reduced heart rate variability in hypertension: associations with lifestyle factors and plasma renin activity.  

Science.gov (United States)

Limited information exists on the relations between heart rate variability, hypertension, lifestyle factors and renin-angiotensin-aldosterone system. A total of 191 newly diagnosed yet untreated hypertensive men and women, 35-54 years of age, were compared with an age- and gender-stratified random population sample of 105 normotensive men and women to find out independent determinants of heart rate variability. Heart rate variability was computed from 5-min ECG time series using the standard deviation of normal-to-normal RR intervals (SDNN), the square root of the mean of squared differences between adjacent normal RR intervals (RMSSD) and the fast Fourier transform spectral analysis. All absolute measures of heart rate variability were reduced in hypertension (Ppowers; Ppower) and higher mean arterial pressure (Ppower, Psodium and alcohol intakes, body mass index and smoking. Increased plasma renin activity (PRA) was an independent attributor of reduced HF power (P<0.05) and reduced RMSSD (P<0.01). Increased blood pressure and heart rate are associated with decreased heart rate variability without any direct effects on heart rate variability of lifestyle factors. High PRA is an independent determinant of diminished modulation of vagal activity. PMID:12624607

Virtanen, R; Jula, A; Kuusela, T; Helenius, H; Voipio-Pulkki, L-M

2003-03-01

287

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

Directory of Open Access Journals (Sweden)

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

288

Ventricular high-rate episodes predict increased mortality in heart failure patients treated with cardiac resynchronization therapy.  

Science.gov (United States)

Abstract Objectives. Cardiac Resynchronization Therapy (CRT) for heart-failure patients has a well-documented positive effect, but the overall mortality in this group remains high. This study aimed to explore whether additional information from the device post-implant (occurrence of ventricular high-rate episodes), could add prognostic value for patients on CRT-pacemaker (CRT-P) treatment. Design. Clinical data and device-interrogation data were retrospectively gathered from the medical records of 220 patients treated with CRT-P. Ventricular high-rate (VHR) episodes were defined as a ventricular rate ? 180 beats per minute. The primary outcome was 5-year mortality. Results. During follow-up, 132 patients (60%) died or underwent heart transplant. Overall, the 5-year mortality rate was 52%; 77% for patients with VHR during the first year of follow-up and 48% for patients without VHR during the first year of follow-up (p = 0.001). In a multivariate model, the occurrence of VHR episodes was an independent predictor of 5-year mortality (HR 9.96, p = 0.022). The most common cause of death was heart failure, and death from arrhythmia did not differ between groups (p = 0.065). Conclusions. In heart-failure patients with CRT-P therapy, occurrence of VHR episodes within the first year post-implant was an independent predictor of higher 5-year mortality and inferior long-term survival, but not of death from malignant arrhythmia. PMID:25658030

Jacobsson, Jonatan; Reitan, Christian; Platonov, Pyotr G; Borgquist, Rasmus

2015-02-01

289

Heart rate changes during the Valsalva maneuver in patients with isolated aortic insufficiency  

Directory of Open Access Journals (Sweden)

Full Text Available To determine the possible relationship between left ventricular dilatation and heart rate changes provoked by the Valsalva maneuver (Valsalva ratio, we studied 9 patients with isolated chronic aortic insufficiency. Left ventricular systolic function was assessed by two-dimensional echocardiography and cardiac catheterization. All patients were asymptomatic (functional class I of the New York Heart Association. The left ventricular internal diameters and volumes were significantly increased in all patients. The asymptomatic patients had either normal or slightly depressed ejection fraction (EF>0.40. The Valsalva ratio of these asymptomatic patients showed no significant correlation with the left ventricular volumes or with the left ventricular ejection fraction. In other words, parasympathetic heart rate control, as expressed by the Valsalva ratio, was normal in the asymptomatic patients with left ventricular dilatation and preserved left ventricular ejection fraction. Therefore, left ventricular dilatation may not be the major mechanism responsible for the abnormal parasympathetic heart rate control of patients with acquired heart disease

Navarro A.E.

1997-01-01

290

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

Science.gov (United States)

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

291

Heart-rate changes on standing in elderly patients with orthostatic hypotension.  

OpenAIRE

1. The heart-rate changes on standing were studied in 16 elderly patients with idiopathic orthostatic hypotension and compared with those of 20 controls. The mean age of both groups was 78 years, and all were in sinus rhythm. 2. The patients with orthostatic hypotension differed from the control patients in having no early peak in heart rate, and a significantly smaller and slower rise in heart rate within the first 40 s after standing (P less than 0.05). 3. It is concluded that there is a fa...

White, Nj

1980-01-01

292

Maternal rectal temperature and fetal heart rate responses to upright cycling in late pregnancy.  

OpenAIRE

OBJECTIVE--To assess maternal rectal temperature and fetal heart rate responses to dynamic exercise. METHODS--11 healthy women with low risk pregnancies completed three separate upright cycling tests at 34 to 37 weeks gestation: 15 min at 62.5 W (mean maternal heart rate [MHR] 138 beats.min-1 (test A); 15 min at 87.5 W (MHR 156 beats.min-1) (test B); and 30 min at 62.5 W (MHR 142 beats.min-1) (test C). Rectal temperature and fetal heart rate were measured. RESULTS--Mean temperature increase a...

O Neill, M. E.

1996-01-01

293

Relationships between heart rate and PR interval during physiological and pharmacological interventions.  

OpenAIRE

The relationships between heart rates (HR) and corresponding PR intervals (PR) were studied in 12 healthy young subjects during rest, standing and graduated treadmill exercise to heart rates of 160 to 170 beats min-1 and during the infusion of isoprenaline to heart rates of 100 to 110 beats min-1. During exercise, PR diminished with increasing HR. Over the range of HR from 60 to 160 beats min-1 all 12 individual subjects exhibited negative linear correlations between HR and PR described by th...

Carruthers, S. G.; Mccall, B.; Cordell, B. A.; Wu, R.

1987-01-01

294

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

OpenAIRE

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

295

NK1-receptor-expressing paraventricular nucleus neurones modulate daily variation in heart rate and stress-induced changes in heart rate variability.  

Science.gov (United States)

The paraventricular nucleus of the hypothalamus (PVN) is an established center of cardiovascular control, receiving projections from other nuclei of the hypothalamus such as the dorsomedial hypothalamus and the suprachiasmatic nucleus. The PVN contains a population of "pre-autonomic neurones" which project to the intermediolateralis of the spinal cord and increase sympathetic activity, blood pressure, and heart rate. These spinally projecting neurones express a number of membrane receptors including GABA and substance P NK1 receptors. Activation of NK1-expressing neurones increases heart rate, blood pressure, and sympathetic activity. However, their role in the pattern of overall cardiovascular control remains unknown. In this work, we use specific saporin lesion of NK1-expressing PVN rat neurones with SSP-SAP and telemetrically measure resting heart rate and heart rate variability (HRV) parameters in response to mild psychological stress. The HRV parameter "low frequency/high frequency ratio" is often used as an indicator of sympathetic activity and is significantly increased with psychological stress in control rats (0.84 ± 0.14 to 2.02 ± 0.15; P stress-induced increase in this parameter to be blunted in the SSP-SAP-lesioned rats (0.83 ± 0.09 to 0.93 ± 0.21; P > 0.05; n = 3). We also find a shift in daily variation of heart rate rhythm and conclude that NK1-expressing PVN neurones are involved with coupling of the cardiovascular system to daily heart rate variation and the sympathetic response to psychological stress. PMID:25472606

Feetham, Claire H; Barrett-Jolley, Richard

2014-12-01

296

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

International Nuclear Information System (INIS)

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

297

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

Directory of Open Access Journals (Sweden)

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

298

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

Energy Technology Data Exchange (ETDEWEB)

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

299

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english 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; Júlia Maria D' Andréa, Greve.

300

Discrepancy between training, competition and laboratory measures of maximum heart rate in NCAA division 2 distance runners  

OpenAIRE

A percentage of either measured or predicted maximum heart rate is commonly used to prescribe and measure exercise intensity. However, maximum heart rate in athletes may be greater during competition or training than during laboratory exercise testing. Thus, the aim of the present investigation was to determine if endurance-trained runners train and compete at or above laboratory measures of 'maximum' heart rate. Maximum heart rates were measured utilising a treadmill graded exercise test (GX...

Stahlnecker Iv, Alvah C.; Katherine Semin; Kate Heelan; Brown, Gregory A.; Shaw, Brandon S.; Ina Shaw

2008-01-01

301

Premature Born Infant's Reaction to the Mother's Voice in Comparison to their Reaction to Music - Effect on Heart Rate and Heart Rate Variability  

OpenAIRE

OBJECTIVE: The aim of the study was to compare stress-reduction effects of the mother’s voice and lullaby music in preterm infants and to explore whether the mother’s well-being affects her ability to calm down her preterm baby. It was hypothesized that both acoustic stimulation interventions can calm down the baby, i.e. decrease heart rate and increase heart rate variability (HRV) in preterm infants. Further it was hypothesized that the mother’s voice would have greater effect than lul...

Djordjevic, Dragana

2010-01-01

302

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

Science.gov (United States)

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

303

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

Directory of Open Access Journals (Sweden)

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

Muneo Kitajima

2011-03-01

304

Heart Rate Variability is a Predictor of Mortality in CKD - A Report from the CRIC Study  

Science.gov (United States)

Background/Aims Low heart rate variability (HRV) is a risk factor for adverse outcomes in the general population. We aimed to determine the factors associated with HRV and evaluate the association between low HRV and clinical outcomes in patients with chronic kidney disease (CKD). Methods A 10 second electrocardiogram was obtained at baseline in the Chronic Renal Insufficiency Cohort (CRIC) Study. HRV was measured by the standard deviation of all R-R intervals (SDNN) and the root mean square of successive differences between R-R intervals (RMSSD). Results In 3245 CRIC participants with available baseline SDNN and RMSSD, lower HRV was associated with older age, lack of exercise, heart failure, elevated phosphorus and hemoglobin A1c, and low estimated glomerular filtration rate. After a median follow-up of 4.2 years, in fully adjusted models, lower HRV was not associated with renal (SDNN: HR=0.96 (95% CI 0.88–1.05); RMSSD: HR=0.97 (95% CI 0.88–1.07)) or cardiovascular outcomes (SDNN: HR=1.02 (95% CI 0.92–1.13); RMSSD: HR=1.00 (95% CI 0.90–1.10)). There was a non-linear relationship between RMSSD and all-cause mortality with increased risk with both low and high RMSSD (P=0.04). Conclusions In a large cohort of participants with CKD, multiple risk factors for renal and cardiovascular disease were associated with lower HRV. Lower HRV was not associated with increased risk for renal or cardiovascular outcomes, but both low and high RMSSD were associated with increased risk for all-cause mortality. In conclusion, HRV as measured by RMSSD may be a novel and independent risk factor for mortality in CKD patients. PMID:24356377

Drawz, Paul E; Babineau, Denise C; Brecklin, Carolyn; He, Jiang; Kallem, Radhakrishna R; Soliman, Elsayed Z; Xie, Dawei; Appleby, Dina; Anderson, Amanda H; Rahman, Mahboob

2014-01-01

305

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 myocardance estimation, and the change of myocardial clearance with heart rate seems less than previously suggested

306

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

Energy Technology Data Exchange (ETDEWEB)

The effects of heart rate on the myocardial uptake and clearance of {sup 201}Tl 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 {sup 201}Tl 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) {sup 201}Tl 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 {sup 201}Tl activity. Submaximal exercise may reduce reproducibility of clearance estimation, and the change of myocardial clearance with heart rate seems less than previously suggested.

Nordrehaug, J.E.; Danielsen, R.; Vik-Mo, H. (Univ. of Bergen, Haukeland Hospital (Norway))

1989-12-01

307

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

308

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

Science.gov (United States)

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 the dose of PGI2 was increased. 4 Female beagles were less sensitive than males to the stimulation of a reflex bradycardia by PGI2. 5 The influence of prostaglandin E2 (PGE2) and bradykinin on heart rate was also found to depend upon the basal state in some dogs. 6 Bilateral vagotomy reversed the bradycardia provoked by PGI2, PGE2 and bradykinin. 7 Thus, PGI2-induced bradycardia in dependent on both the dose and the basal heart rate. Similarly the effects of PGE2 and bradykinin on heart rate also depend upon the basal state in some dogs. Moreover, there is a correlation between the ability of all three agonists to induce bradycardia, suggesting a common mechanism of action. PMID:7042022

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

1982-01-01

309

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

310

Lactic acidosis, potassium, and the heart rate deflection point in professional road cyclists  

OpenAIRE

Objective: To determine the influence of lactic acidosis, the Bohr effect, and exercise induced hyperkalaemia on the occurrence of the heart rate deflection point (HRDP) in elite (professional) cyclists.

Lucia, A.; Hoyos, J.; Santalla, A.; Perez, M.; Carvajal, A.; Chicharro, J.

2002-01-01

311

Effect of ultramarathon cycling on the heart rate in elite cyclists  

OpenAIRE

Objectives: To analyse the heart rate (HR) response and estimate the ultraendurance threshold—the optimum maintainable exercise intensity of ultraendurance cycling—in ultraendurance elite cyclists competing in the Race across the Alps.

Neumayr, G.; Pfister, R.; Mitterbauer, G.; Maurer, A.; Hoertnagl, H.

2004-01-01

312

Do nicotine intake and acute heart rate response to smoking rank nicotine dependence the same?  

Science.gov (United States)

In this study, two proposed scales of nicotine dependence were compared: self-administered nicotine intake and acute heart rate sensitivity to smoking. Our aim was to determine if these nicotine dependence scales would rank relative dependence the same in a sample of 15 male chronic smokers who smoked their first cigarette in the morning after overnight abstinence. Heart rate and plasma nicotine levels were measured before and 5, 10, 15, and 30 min after smoking. The results of this pilot study suggest that heart rate sensitivity and nicotine intake do not have a direct linear relationship, but rather a curvilinear relationship. A marked increase in heart rate sensitivity was observed at approximately the 70th percentile of nicotine intake. PMID:23788189

Walker, Jerome F; Loprinzi, Paul D; Kane, Christy J

2013-06-25

313

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

Science.gov (United States)

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

314

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)

315

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

Science.gov (United States)

Scaling analysis of heart rate time series has emerged as a useful tool for the 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 min and subsequently heart rate time series are extracted and artifacts filtered. We find three distinct regions of scale invariance, which correspond to the well-known VLF, LF and HF bands in the power spectra of heart rate variability. The scaling exponents alpha are alpha(HF): 1.15 [0.96-1.22], alpha(LF): 0.68 [0.57-0.84], alpha(VLF): 0.83[0.82-0.99], p VLF, LF and HF ranges, respectively. PMID:16868343

Baumert, Mathias; Brechtel, Lars M; Lock, Juergen; Voss, Andreas; Abbott, Derek

2006-09-01

316

Neighborhood blight, stress, and health: a walking trial of urban greening and ambulatory heart rate.  

Science.gov (United States)

We measured dynamic stress responses using ambulatory heart rate monitoring as participants in Philadelphia, Pennsylvania walked past vacant lots before and after a greening remediation treatment of randomly selected lots. Being in view of a greened vacant lot decreased heart rate significantly more than did being in view of a nongreened vacant lot or not in view of any vacant lot. Remediating neighborhood blight may reduce stress and improve health. PMID:25790382

South, Eugenia C; Kondo, Michelle C; Cheney, Rose A; Branas, Charles C

2015-05-01

317

Chaotic Behavior of Heart Rate Signals during Chi and Kundalini Meditation  

OpenAIRE

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

318

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

OpenAIRE

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

319

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

OpenAIRE

The present article contains a brief review on the role of vasopressinergic projections to the nucleus tractus solitarii in the genesis of reflex bradycardia and in the modulation of heart rate control during exercise. The effects of vasopressin on exercise tachycardia are discussed on the basis of both the endogenous peptide content changes and the heart rate response changes observed during running in sedentary and trained rats. Dynamic exercise caused a specific vasopressin content increas...

Michelini, L. C.

1998-01-01

320

Weight loss and exercise training effect on oxygen uptake and heart rate response to locomotion  

OpenAIRE

Effects of resistance and aerobic training on ease of physical activity during and following weight loss are unknown. Purpose of study is to determine what affect weight loss combined with either aerobic or resistance training has on ease of locomotion (netVO2 and heart rate). It is hypothesized that exercise training will result in increased ease, lower heart rate during locomotion. Seventy three overweight, premenopausal women were assigned to diet and aerobic training, diet and resistance ...

Hunter, Gary R.; Fisher, Gordon; Bryan, David R.; Zuckerman, Paul A.

2012-01-01

321

Dose-dependent heart rate reducing effect of nizatidine, a histamine H2-receptor antagonist.  

OpenAIRE

1. Twelve healthy subjects were treated in a randomised placebo-controlled crossover study with placebo, 150 mg, 300 mg, and 600 mg nizatidine, 100 mg pirenzepine, and 300 mg nizatidine plus 100 mg pirenzepine for 1 week each. 2. On the seventh treatment day, heart rate, blood pressure, systolic time intervals, impedance cardiographic and Doppler ultrasound variables were measured. 3. Stroke volume and blood pressure were not altered by nizatidine and/or pirenzepine. By contrast, heart rate a...

Hinrichsen, H.; Halabi, A.; Fuhrmann, G.; Kirch, W.

1993-01-01

322

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

OpenAIRE

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

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

2012-01-01

323

Heart Rate Variability Responses of a Preterm Infant to Kangaroo Care  

Science.gov (United States)

A 35-week old preterm infant's behavior was fussy and restless in the open crib, but he calmed and fell asleep immediately on being placed skin-to-skin on his mother's chest. Heart rate variability (HRV), a noninvasive method to assess the autonomic nervous system's influence on heart rate, was increased with fussy behavior in the open crib and decreased with sleep during kangaroo care (KC). KC produced changes in behavior and HRV that are illustrative of decreasing stress. PMID:16282226

McCain, Gail C.; Ludington-Hoe, Susan M.; Swinth, Joan Y.; Hadeed, Anthony J.

2006-01-01

324

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

OpenAIRE

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

325

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

OpenAIRE

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

Lacount, Lt; Napadow, V.; Kuo, B.; Park, K.; Kim, J.; Brown, En; Barbieri, R.

2009-01-01

326

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

OpenAIRE

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

327

Habitual physical activity and heart rate variability in 12-year old children  

OpenAIRE

ABSTRACT Wennman, Heini 2012. Habitual physical activity and heart rate variability in 12-year old children. Department of Biology of Physical Activity, University of Jyväskylä, 92p. The study of heart rate variability (HRV) provides useful information about the function of the cardiac autonomic nervous system. The effects of many environmental factors on HRV are well known, but the associations between physical activity (PA) and HRV, especially in children, are less investigated. ...

Wennman, Heini

2012-01-01

328

Nonlinear systems dynamics in cardiovascular physiology: The heart rate delay map and lower body negative pressure  

Science.gov (United States)

A preliminary study of the applicability of nonlinear dynamic systems analysis techniques to low body negative pressure (LBNP) studies. In particular, the applicability of the heart rate delay map is investigated. It is suggested that the heart rate delay map has potential as a supplemental tool in the assessment of subject performance in LBNP tests and possibly in the determination of susceptibility to cardiovascular deconditioning with spaceflight.

Hooker, John C.

1990-01-01

329

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

OpenAIRE

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. Concl...

Ping Liu,; Chaxi Huang; Yingxue Cui; Lu Wang; Jun Li; Baixiao Zhao; Gerhard Litscher

2011-01-01

330

Estimation system of cardiovascular circulatory system state based on 24h heart rate  

OpenAIRE

The goal of this research was to develop the methods and tools for the analysis of cardiovascular circulatory system states, early prediction of the probability of sudden cardiac arrest, as well as analysis of various cardiac arrhythmias based on the dynamics of the 24-hours heart rate. Using «k-means" method based on MacQueen algorithm, the automated classification of heart rate fragments was made. The most informative procedure was referring specific observation to the functional patter...

Kyselova, Olga; Nastenko, Yevgen

2013-01-01

331

Effect of decrease in heart rate variability on the diagnostic accuracy of 64-MDCT coronary angiography  

OpenAIRE

OBJECTIVE: The purpose of this study was to evaluate the effect of average heart rate and heart rate variability on the diagnostic accuracy of 64-MDCT in the assessment of coronary artery stenosis. SUBJECTS AND METHODS: CT and invasive coronary angiography were performed on 114 patients (mean age, 62 years) referred for known coronary artery disease (n = 26), atypical chest pain (n = 58), and presurgical exclusion of coronary artery disease before abdominal aortic (n = 14) or cardiac valve (n...

Leschka, S.; Scheffel, H.; Husmann, L.; Ga?mperli, O.; Marincek, B.; Kaufmann, P. A.; Alkadhi, H.

2008-01-01

332

The Effects of distilled Wild Ginseng Herbal Acupuncture on the Heart Rate Variability(HRV)  

OpenAIRE

Objective : We investigated the effects of distilled Wild Ginseng Herbal Acupuncture on autonomic nervous system with the Heart Rate Variability(HRV) in adult man. as well as we tried to observe how distilled Wild Ginseng Herbal Acupuncture on the balance of the autonomic nervous system. Method : We investigated the effects of distilled Wild Ginseng Herbal Acupuncture on autonomic nervous system with the Heart Rate Variability(HRV) in adult man. as well as we tried to observe how dis...

Roh Jeong-Du; Kim Lak-Hyung; Song Beom-Yong; Yook Tae-Han

2008-01-01

333

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

334

Bradycardia in perspective-not all reductions in heart rate need immediate intervention.  

Science.gov (United States)

According to Wikipedia, the word 'bradycardia' stems from the Greek ??????, bradys, 'slow', and ??????, kardia, 'heart'. Thus, the meaning of bradycardia is slow heart rate but not necessarily too slow heart rate. If looking at top endurance athletes they may have a resting heart rate in the very low thirties without needing emergent intervention with anticholinergics, isoprenaline, epinephrine, chest compressions or the insertion of an emergency pacemaker (Figure 1). In fact, they withstand these episodes without incident, accommodating with a compensatory increase in stroke volume to preserve and maintain cardiac output. With this in mind, it is difficult for the authors to fully understand and agree with the general sentiment amongst many pediatric anesthesiologists that all isolated bradycardia portends impending doom and must be immediately treated with resuscitative measures. PMID:25410284

Mason, Keira P; Lönnqvist, Per-Arne

2015-01-01

335

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)

336

The Relationship Between Ambient Air Pollution and Heart Rate Variability Differs for Individuals with Heart and Pulmonary Disease  

OpenAIRE

Associations between concentrations of ambient fine particles [particulate matter < 2.5 ?m aerodynamic diameter (PM\\(_{2.5}\\))] and heart rate variability (HRV) have differed by study population. We examined the effects of ambient pollution on HRV for 18 individuals with chronic obstructive pulmonary disease (COPD) and 12 individuals with recent myocardial infarction (MI) living in Atlanta, Georgia. HRV, baseline pulmonary function, and medication data were collected for each participant on ...

Wheeler, Amanda; Zanobetti, Antonella; Gold, Diane R.; Schwartz, Joel David; Stone, Peter Howard; Suh Macintosh, Helen H.

2005-01-01

337

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

338

Effect of increasing age on adrenergic control of heart rate in the rat.  

Science.gov (United States)

To determine if decreased cardiac rate with increasing age in Fischer-344 rats was due to changes in the heart itself, in adrenergic nerves innervating the heart or in both, we studied heart rate in vivo and in vitro, and atrial and ventricular pacemaker activity in vitro following atrioventricular block, in control and in chemically sympathectomized rats [pretreated with 6-hydroxydopamine (6-OHDA), 20 mg/kg, s.c., 24 h prior to testing] at ages 1 to 28 months. With increasing age, heart rate (bpm) in vivo decreased from 440 +/- 12 to 385 +/- 10 in the control and from 403 +/- 20 to 318 +/- 11 in 6-OHDA pretreated rats; heart rate in vitro decreased from 353 +/- 9 to 243 +/- 8 in the control, and from 346 +/- 15 to 214 +/- 18 in 6-OHDA pretreated rats; the atrial rate (AR) decreased from 304 +/- 9 to 210 +/- 8 in the control and from 288 +/- 13 to 161 +/- 32 in 6-OHDA pretreated rats while the ventricular pacemaker rate (VR) decreased from 121 +/- 8 to 92 +/- 5 in the control, and from 100 +/- 14 to 70 +/- 7 in 6-OHDA pretreated rats. With age, AR decreased to a greater extent than VR and 6-OHDA had a greater effect in decreasing AR than VR. Using cardiac rate as a measure, it appears that with age changes in the pacemakers of the heart themselves (postjunctional) as well as in the adrenergic nerve endings innervating the heart (prejunctional) contribute to decreased cardiac rate and pacemaker activity in older rats. PMID:3136028

Goldberg, P B; Tumer, N; Roberts, J

1988-01-01

339

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

340

Initial experience of evaluation of coronary artery with 320-slice row CT system in high pre-test probability population without heart rate (rhythm) control  

International Nuclear Information System (INIS)

Objective: To investigate the accuracy of 320-slice row CT system for the detection of coronary artery disease (CAD) in high pre-test probability population without heart rate/rhythm control. Methods: Thirty patients with a high pre-test probability of CAD underwent 320-slice row CT without preceding heart rate/rhythm control. Invasive coronary angiography (ICA) served as the standard reference. Data sets were evaluated by 2 observers in consensus with respect to stenoses ?50% decreased diameter. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and Youden index were analyzed; the impact of heart rate and calcification on image quality as well as diagnostic accuracy were also analyzed by Chi-square test. Results: Mean heart rate during scanning was 73.7±15.4 beats per min(bpm), and median(QR) of Agatston score of segment was 45.6 (181). On a per-segment analysis, overall sensitivity was 96.1% (74/77, 95% CI:89.03%-99.19%), specificity was 98.3% (337/343, 95% CI:96.23%-99.36%), PPV was 92.5% (74/80, 95% CI:84.39%-97.20%), NPV of 99.1% (337/340, 95% CI: 97.44%-99.82%) and the Youden index was 0.94. In both heart-rate subgroups (242 in heart rate < 70 bpm group, 169 in heart rate ?70 bpm group), diagnostic accuracy for the assessment of coronary artery stenosis was similar (P<0.05). The accuracy and the quality score of the subgroup Agatston score ?100 were lower than that of the subgroup Agatston score <100; however, toup Agatston score <100; however, the difference of results between 320-slice row CT and ICA was not significant (P<0.05). Conclusion: 320-detector row CT can reliably detect coronary artery stenoses in a high pre-test probability population without heart rate/rhythm control. (authors)

341

Discrepancy between training, competition and laboratory measures of maximum heart rate in NCAA division 2 distance runners.  

Science.gov (United States)

A percentage of either measured or predicted maximum heart rate is commonly used to prescribe and measure exercise intensity. However, maximum heart rate in athletes may be greater during competition or training than during laboratory exercise testing. Thus, the aim of the present investigation was to determine if endurance-trained runners train and compete at or above laboratory measures of 'maximum' heart rate. Maximum heart rates were measured utilising a treadmill graded exercise test (GXT) in a laboratory setting using 10 female and 10 male National Collegiate Athletic Association (NCAA) division 2 cross-country and distance event track athletes. Maximum training and competition heart rates were measured during a high-intensity interval training day (TR HR) and during competition (COMP HR) at an NCAA meet. TR HR (207 ± 5.0 b·min(-1); means ± SEM) and COMP HR (206 ± 4 b·min(-1)) were significantly (p VO2 max with no differences between the men and women. However, the heart rate at the ventilatory threshold measured in the laboratory was only 77% of the maximal COMP HR or TR HR. In order to optimize training-induced adaptation, training intensity for NCAA division 2 distance event runners should not be based on laboratory assessment of maximum heart rate, but instead on maximum heart rate obtained either during training or during competition. Key pointsA percentage of maximum heart rate is commonly used to prescribe and measure exercise intensity. However, maximum heart rate may be greater during competition or training than during laboratory exercise testing.Heart rates during training and competition were significantly higher than maximum heart rates obtained during laboratory exercise testing.To optimize training-induced adaptation, training intensity for NCAA division 2 distance event runners should not be based on laboratory assessment of maximum heart rate, but instead on maximum heart rate measure obtained either during training or during competition. PMID:24149950

Semin, Katherine; Stahlnecker Iv, Alvah C; Heelan, Kate; Brown, Gregory A; Shaw, Brandon S; Shaw, Ina

2008-01-01

342

Kangaroo Care Modifies Preterm Infant Heart Rate Variability in Response to Heel Stick Pain: Pilot Study  

Science.gov (United States)

Background Heel stick is the most common painful procedure for preterm infants in neonatal intensive care units. Resultant pain causes adverse physiological effects in major organ systems. Kangaroo Care (KC), involving mother-infant skin-to-skin contact is a promising analgesic for infant pain; however, the effect of KC on the autonomic nervous system's response to pain is unknown. Aim To determine if KC results in improved balance in autonomic responses to heel stick pain than the standard method where infants remain in an incubator care (IC) for the heel stick. Study Design A randomized cross-over trial. Subjects Fourteen preterm infants, 30-32 weeks gestational age and less than 9 days postnatal age. Outcome Measures Infant behavioral state, heart rate, heart rate variability (HRV) indices including low frequency (LF) and high frequency (HF) power, and the LF/HF ratio measured over Baseline, Heel Warming, Heel Stick, and Recovery periods in KC and IC conditions. Results HRV differences between KC and IC were that LF was higher in KC at Baseline (p<.01) and at Heel Stick (p< .001), and HF was higher in KC at Baseline than in the IC condition (p< .05). The LF/HF ratio had less fluctuation across the periods in KC than in IC condition and was significantly lower during Recovery in KC than in IC (p< .001). Conclusions Infants experienced better balance in response in KC than IC condition as shown by more autonomic stability during heel stick. KC may be helpful in mediating physiologic response to painful procedures in preterm infants. PMID:19505775

Cong, Xiaomei; Ludington-Hoe, Susan M.; McCain, Gail; Fu, Pingfu

2009-01-01

343

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

Energy Technology Data Exchange (ETDEWEB)

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

344

Characteristics of sleep parameters and nocturnal heart rate dynamics in patients with psoriasis vulgaris  

Directory of Open Access Journals (Sweden)

Full Text Available Objective To investigate the physiological features of patients with psoriasis vulgaris during sleep.Methods Thirty-six psoriasis patients were classified into the group with "blood-heat" syndrome(n=21 and the group with "blood-dry" syndrome(n=15.Fifteen healthy volunteers served as control.All the subjects underwent a nocturnal sleep examination using the micro-movement sensitive mattress sleep monitoring system(MSMSMS.The sleep indices and nocturnal heart rate dynamics of the patients were compared with that of the control,and also between the two groups with different syndrome.Results In comparison with the control group,both psoriasis patient groups showed the phenomena of poor sleep quality,such as the shallow sleep phase,disorder of sleep rhythm and increased slight-arousals.The slight-arousal occurred more often in blood-heat syndrome group than in blood-dry syndrome group,while the sleep latency was elongated more evidently in blood-dry syndrome group.Compared with the control group,the two patient groups presented a little decrease in heart rate(HR after sleeping.However,the HR increased in the first phase of sleep,and the variation coefficient of HR increased in the whole sleep period.An increase in HR variation coefficient was more obvious in blood-heat syndrome group than in blood-dry syndrome group(P < 0.05.Conclusions The phenomena of decreased sleep quality and the variation of nocturnal HR in psoriasis patients may be due to the failure of Yin to control Yang,and disturbance of heat to the mind induced by blood-heat and Yin deficiency.The degrees of the phenomena are different between the two psoriasis groups.There is also a decrease in parasympathetic activity and relative increase in sympathetic activity in both psoriasis groups,with manifestation of different features in patients with different syndromes.

Rang-song HUI

2011-11-01

345

Post-Plyometric Exercise Hypotension and Heart Rate in Normotensive Individuals: Influence of Exercise Intensity  

Science.gov (United States)

Purpose The purpose of this study was to compare the effects of high, moderate and low intensity plyometric exercise on the post-exercise systolic and diastolic blood pressure and heart rate responses. Methods Ten healthy normotensive men (age, 21.1±0.9 years; height, 175.8±6 cm; and body mass, 69.1±13.6 kg) volunteered to participate in this study and were evaluated for three non-consecutive days in depth jump exercise from 20-cm box (low intensity [LI]), 40-cm box (moderate intensity [MI]) and 60-cm box (high intensity [HI]) for 5 sets of 20 repetitions. After each exercise session, systolic blood pressure (SBP), diastolic blood pressure (DBP) and heart rate (HR) were measured every 10 min for a period of 90 min. Results No significant differences were observed among post-exercise SBP, DBP and HR when the protocols (LI, MI and HI) were compared. The LI and HI protocols showed greater reduction in SBP at 40th-70th min of post-exercise (~9%), whereas the LI and MI protocols indicated greater reduction in DBP at 10th-50th min of post exercise (~10%). In addition, the change in the DBP for HI was not significant and the increases in the HR were similar for all intensities. Conclusion It can be concluded that a plyometric exercise (PE) can reduce SBP and DBP post-exercise and therefore we can say that PE has significant effects for reducing BP and HR or post-exercise hypotension. PMID:24799997

Arazi, Hamid; Asadi, Abbas; Rahimzadeh, Mehdi; Moradkhani, Amir-Hossein

2013-01-01

346

Reduced Heart Rate Variability Is Associated With Increased Arterial Stiffness in Youth With Type 1 Diabetes  

Science.gov (United States)

OBJECTIVE Reduced heart rate variability (HRV) and increased arterial stiffness (AS) are both present in youth with type 1 diabetes. However, it is unclear whether they are associated and whether their association is independent of cardiovascular disease (CVD) risk factors. RESEARCH DESIGN AND METHODS The SEARCH Cardiovascular Disease (SEARCH CVD) study explored the cross-sectional relationships between HRV and several measures of AS in youth with (n = 344) and without (n = 171) type 1 diabetes. The SphygmoCor device (AtCor Medical, Sydney, Australia) was used to measure HRV using SD of normal R-R interval (SDNN), as well as AS, using pulse wave velocity in the carotid to femoral segment (PWV-trunk) and augmentation index adjusted to a heart rate of 75 bpm (AIx75). Brachial distensibility (BrachD), another index of AS, was measured with a DynaPulse instrument (Pulse Metric, San Diego, CA). Multiple linear regression analyses explored the associations between HRV and each of the three AS measures, after adjusting for demographic characteristics and traditional CVD risk factors (blood pressure, lipids, obesity, microalbuminuria, and smoking) separately, for youth with and without type 1 diabetes. RESULTS Among youth with type 1 diabetes, lower SDNN was associated with peripheral AS (lower BrachD, P = 0.01; r2 = 0.30) and central AS (higher PVW-trunk, P < 0.0001; r2 = 0.37; and higher AIx75, P = 0.007; r2 = 0.08). These associations were attenuated with adjustment for CVD risk factors, but remained statistically significant for BrachD and PWV-trunk. While a similar association between HRV and BrachD was present in control youth, lower HRV was not associated with increased central AS or with AIx75. CONCLUSIONS Longitudinal studies are needed to understand the pathways responsible for these associations. PMID:23435158

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

2013-01-01

347

‘Fire of Life’ analysis of heart rate variability during alpine skiing in Austria  

Directory of Open Access Journals (Sweden)

Full Text Available Background: Skiing is a very popular sport in Austria. Nevertheless, there is little information concerning online monitoring of bio-signals during alpine skiing in the mountains. 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 the new ‘Fire of Life’ heart rate variability analysis for the first time during alpine skiing. Volunteers and Methods: Continuous electrocardiographic monitoring over a period of 12 hours was performed simultaneously in two healthy volunteers using the same type of equipment (medilog AR12 systems. Two healthy volunteers (female, 20 years, and male, 51 years, both hobby skiers, were monitored simultaneously and continuously during two resting periods before and after active sport and also during alpine skiing. Altogether each participant covered 9,084 meters altitude difference within a time period of 6:14 hours. Total length of the downhill skiing was 45 kilometers. 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 respiratory sinus arrhythmia and blood pressure effects can be clearly seen in the young female. The same effects, however markedly reduced, are obvious in the older volunteer. Conclusions: The present investigations during alpine skiing highlight the potential value of the ‘Fire of Life’ heart rate variability monitoring even under difficult environmental conditions. The innovative kind of analysis helps to show how well the human body reacts to sport, stress and recovery.

Gerhard Litscher

2010-06-01

348

Validity of a heart rate monitor during work in the laboratory and on the Space Shuttle.  

Science.gov (United States)

Accurate heart rate measurement during work is required for many industrial hygiene and ergonomics situations. The purpose of this investigation was to determine the validity of heart rate measurements obtained by a simple, lightweight, commercially available wrist-worn heart rate monitor (HRM) during work (cycle exercise) sessions conducted in the laboratory and also during the particularly challenging work environment of space flight. Three different comparisons were made. The first compared HRM data to simultaneous electrocardiogram (ECG) recordings of varying heart rates that were generated by an ECG simulator. The second compared HRM data to ECG recordings collected during work sessions of 14 subjects in the laboratory. Finally, ECG downlink and HRM data were compared in four astronauts who performed cycle exercise during space flight. The data were analyzed using regression techniques. The results were that the HRM recorded virtually identical heart rates compared with ECG recordings for the data set generated by an ECG simulator. The regression equation for the relationship between ECG versus HRM heart rate data during work in the laboratory was: ECG HR = 0.99 x (HRM) + 0.82 (r2 = 0.99). Finally, the agreement between ECG downlink data and HRM data during space flight was also very high, with the regression equation being: Downlink ECG HR = 1.05 x (HRM) -5.71 (r2 = 0.99). The results of this study indicate that the HRM provides accurate data and may be used to reliably obtain valid data regarding heart rate responses during work. PMID:9115087

Moore, A D; Lee, S M; Greenisen, M C; Bishop, P

1997-04-01

349

Prognostic value of ambulatory heart rate revisited in 6928 subjects from 6 populations  

DEFF Research Database (Denmark)

The evidence relating mortality and morbidity to heart rate remains inconsistent. We performed 24-hour ambulatory blood pressure monitoring in 6928 subjects (not on beta-blockers; mean age: 56.2 years; 46.5% women) enrolled in prospective population studies in Denmark, Belgium, Japan, Sweden, Uruguay, and China. We computed standardized hazard ratios for heart rate, while stratifying for cohort, and adjusting for blood pressure and other cardiovascular risk factors. Over 9.6 years (median), 850, 325, and 493 deaths accrued for total, cardiovascular, and noncardiovascular mortality, respectively. The incidence of fatal combined with nonfatal end points was 805, 363, 439, and 324 for cardiovascular, stroke, cardiac, and coronary events, respectively. Twenty-four-hour heart rate predicted total (hazard ratio: 1.15) and noncardiovascular (hazard ratio: 1.18) mortality but not cardiovascular mortality (hazard ratio: 1.11) or any of the fatal combined with nonfatal events (hazard ratio: or =1.15) but none of the fatal combined with nonfatal events (hazard ratio: or =1.15) with the exception of stroke (hazard ratio: 1.06). Sensitivity analyses, in which we stratified by risk factors or from which we excluded 1 cohort at a time or the events occurring within 2 years of enrollment, showed consistent results. In the general population, heart rate predicts total and noncardiovascular mortality. With the exception of the night:day heart rate ratio, heart rate did not add to the risk stratification for fatal combined with nonfatal cardiovascular events. Thus, heart rate adds little to the predictionof cardiovascular risk Udgivelsesdato: 2008/8

Hansen, Tine Willum; Thijs, Lutgarde

2008-01-01

350

Attenuated heart rate response in REM sleep behavior disorder and Parkinson's disease  

DEFF Research Database (Denmark)

The objective of this study was to determine whether patients with Parkinson's disease with and without rapid?eye?movement sleep behavior disorder and patients with idiopathic rapid?eye?movement sleep behavior disorder have an attenuated heart rate response to arousals or to leg movements during sleep compared with healthy controls. Fourteen and 16 Parkinson's patients with and without rapid?eye?movement sleep behavior disorder, respectively, 11 idiopathic rapid?eye?movement sleep behavior disorder patients, and 17 control subjects underwent 1 night of polysomnography. The heart rate response associated with arousal or leg movement from all sleep stages was analyzed from 10 heartbeats before the onset of the sleep event to 15 heartbeats following onset of the sleep event. The heart rate reponse to arousals was significantly lower in both parkinsonian groups compared with the control group and the idiopathic rapid?eye?movement sleep behavior disorder group. The heart rate response to leg movement was significantly lower in both Parkinson's groups and in the idiopathic rapid?eye?movement sleep behavior disorder group compared with the control group. The heart rate response for the idiopathic rapid?eye?movement sleep behavior disorder group was intermediate with respect to the control and the parkinsonian groups. The attenuated heart rate response may be a manifestation of the autonomic deficits experienced in Parkinson's disease. The idiopathic rapid?eye?movement sleep behavior disorder patients not only exhibited impaired motor symptoms but also incipient autonomic dysfunction, as revealed by the attenuated heart rate response. © 2012 Movement Disorder Society

Sorensen, Gertrud Laura; Kempfner, Jacob

2012-01-01

351

AMBIENT POLLUTION AND HEART RATE VARIABILITY. (R826780)  

Science.gov (United States)

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

352

Accelerated rates of glycolysis in the hypertrophied heart: are they a methodological artifact?  

Science.gov (United States)

Glycolysis, measured by (3)H(2)O production from [5-(3)H]glucose, is accelerated in isolated working hypertrophied rat hearts. However, nonglycolytic detritiation of [5-(3)H]glucose via the nonoxidative pentose phosphate pathway (PPP) could potentially lead to an overestimation of true glycolytic rates, especially in hypertrophied hearts where the PPP may be upregulated. To address this concern, we measured glycolysis using [5-(3)H]glucose and a second, independent method in isolated working hearts from halothane-anesthetized, sham-operated and aortic-constricted rats. Glycolysis was accelerated in hypertrophied hearts compared with control hearts regardless of the method used. There was also excellent concordance in glycolytic rates between the different methods. Moreover, activity of glucose-6-phosphate dehydrogenase and expression of transaldolase, enzymes controlling key steps in the oxidative and nonoxidative PPP, respectively, were not different between control and hypertrophied hearts. Thus nonglycolytic detritiation of [5-(3)H]glucose in the PPP is insignificant, and (3)H(2)O production from [5-(3)H]glucose is an accurate means to measure glycolysis in isolated working normal and hypertrophied rat hearts. Furthermore, the PPP does not appear to be increased in cardiac hypertrophy induced by abdominal aortic constriction. PMID:11934668

Leong, Hon Sing; Grist, Mark; Parsons, Hannah; Wambolt, Richard B; Lopaschuk, Gary D; Brownsey, Roger; Allard, Michael F

2002-05-01

353

Meta-analyzed heart rate variability, exposure to geomagnetic storms, and the risk of ischemic heart disease.  

Science.gov (United States)

The aim was to examine how heart rate variability (HRV) relates to the risk of ischemic heart disease (IHD) and may provide a means to assess effects of exposure to geomagnetic storms. In Stockholm, the 24-hour SD of hourly estimates of heart rate (HR) were obtained by Holter monitoring from 50 men who had had an acute myocardial infarction or had angina pectoris and compared to that of 50 clinically healthy men of similar age. In Tokyo, the HR 121 normotensives and 176 treated hypertensives was monitored. The incidence of IHD was recorded prospectively for 6 years. These results are aligned with those of a retrospective analysis of archived data on all crews of the Soyuz spacecraft for 1990-1994 focused on ECG from cosmonauts (47 male and 2 female) at times corresponding to geomagnetic storms. The results clearly indicate a decrease in HRV in association with IHD (20.5%, p=0.002 in Stockholm, 20.0%, p=0.04 in Tokyo). By comparison, the about 30% decrease (p=0.041) in rms SD of HR in cosmonauts studied during a geomagnetic storm as compared to cosmonauts monitored on quiet days adds supportive evidence to the proposition that exposure to geomagnetic disturbances increases cardiovascular disease risk. PMID:11543511

Baevsky, R M; Petrov, V M; Cornelissen, G; Halberg, F; Orth-Gomer, K; Akerstedt, T; Otsuka, K; Breus, T; Siegelova, J; Dusek, J; Fiser, B

1997-07-01

354

Heart rate changes during the Valsalva maneuver in patients with isolated aortic insufficiency  

OpenAIRE

To determine the possible relationship between left ventricular dilatation and heart rate changes provoked by the Valsalva maneuver (Valsalva ratio), we studied 9 patients with isolated chronic aortic insufficiency. Left ventricular systolic function was assessed by two-dimensional echocardiography and cardiac catheterization. All patients were asymptomatic (functional class I of the New York Heart Association). The left ventricular internal diameters and volumes were significantly increased ...

Navarro A.E.; Dávila D.F.; Torres A.; Bellabarba G.; Donis J.H.; Casado J.

1997-01-01

355

The compliance of the porcine pulmonary artery depends on pressure and heart rate  

OpenAIRE

1. The influence of mean pulmonary arterial pressure (mean Ppa) on dynamic (Cd) and pseudo-static compliance (Cps) of the pulmonary artery was studied at a constant and a changing heart rate. Cd is the change in cross-sectional area (CSA) relative to the change in Ppa throughout a heart cycle. Cps is the change in mean CSA relative to the change in mean Ppa. If Cd is known, pulmonary blood flow can be computed from the Ppa ...

Kornet, L.; Jansen, J. R. C.; Nijenhuis, F. C. A. M. Te; Langewouters, G. J.; Versprille, A.

1998-01-01

356

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

OpenAIRE

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 rat...

Lim Shih-Hui; Wilder-Smith Einar

2001-01-01

357

Influence of mercury exposure on blood pressure, resting heart rate and heart rate variability in French Polynesians: a cross-sectional study  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Populations which diet is rich in seafood are highly exposed to contaminants such as mercury, which could affect cardiovascular risk factors Objective To assess the associations between mercury and blood pressure (BP, resting heart rate (HR and HR variability (HRV among French Polynesians Methods Data were collected among 180 adults (? 18 years and 101 teenagers (12-17 years. HRV was measured using a two-hour ambulatory electrocardiogram (Holter and BP was measured using a standardized protocol. The association between mercury and HRV and BP parameters was studied using analysis of variance (ANOVA and analysis of covariance (ANCOVA Results Among teenagers, the high frequency (HF decreased between the 2nd and 3rd tertile (380 vs. 204 ms2, p = 0.03 and a similar pattern was observed for the square root of the mean squared differences of successive R-R intervals (rMSSD (43 vs. 30 ms, p = 0.005 after adjusting for confounders. In addition, the ratio low/high frequency (LF/HF increased between the 2nd and 3rd tertile (2.3 vs. 3.0, p = 0.04. Among adults, the standard deviation of R-R intervals (SDNN tended to decrease between the 1st and 2nd tertile (84 vs. 75 ms, p = 0.069 after adjusting for confounders. Furthermore, diastolic BP tended to increase between the 2nd and 3rd tertile (86 vs. 91 mm Hg, p = 0.09. No significant difference was observed in resting HR or pulse pressure (PP Conclusions Mercury was associated with decreased HRV among French Polynesian teenagers while no significant association was observed with resting HR, BP, or PP among teenagers or adults

Valera Beatriz

2011-11-01

358

Ultrasound-induced heart rate decrease: role of the vagus nerve.  

Science.gov (United States)

The goal of this study is to investigate the role of the vagus nerve (VN) in the ultrasound (US)-induced negative chronotropic effect (deceased heart rate). One of the functions of the VN is to mediate lowering of the heart rate. A previous study showed a decrease of ~20% in the heart rate but the mechanism of the effect was not investigated. Sprague Dawley rats (n = 20) were exposed transthoracically to ultrasonic pulses at an approximate duty factor of 1% with sequentially 2.0, 2.5, and 3.0 MPa peak rarefactional pressure amplitudes (PRPAs). The ultrasonic exposure parameters herein were chosen to match those of the previous study to have confidence that an ultrasound-induced negative chronotropic effect would occur. For each of the three PRPA sequences, the pulse repetition frequency (PRF) started slightly greater than the rat's heart rate and then was decreased sequentially in 1-Hz steps every 10 s (i.e., 6, 5, and 4 Hz for a total duration of 30 s). The experiments were organized in a standard (2 × 2) factorial design with VN (cut versus intact) as one factor and US (on versus off) as another factor. VN (intact/cut) and US (on/off) groups were divided into four groups each consisting of 5 animals: 1) VN intact-US off, 2) VN intact-US on, 3) VN cut-US off, and 4) VN cut-US on. Two-way analysis of variance for repeated measures was used to compare heart rate, cardiac output, systolic volume, ejection fraction, end-diastolic volume, end-systolic volume, respiratory rate, and arterial pressure before and after ultrasound stimulation. In this study, the heart rate decreased ~4% for the non-vagotomy and vagotomy groups. The ultrasound effect was significant for heart rate (p = 0.02) and cardiac output (p = 0.005) at 3 min post US exposure; the vagotomy effect was not significant. For heart rate, the Bonferroni test showed no differences between the four groups. The vagotomy group showed similar ultrasound-induced cardiac effects compared with the non-vagotomy group, suggesting that the vagus nerve is not influenced by the ultrasound exposure procedures. The US application caused a negative chronotropic effect of the rat heart without affecting the hemodynamic conditions. The results at this point are suggestive for an alternative cardiac pacing capability. PMID:25643082

Coiado, Olivia; Buiochi, Elaine; O'Brien, William

2015-02-01

359

Evaluation of ischemic heart disease by thallium-201 washout-rate map using SPECT  

International Nuclear Information System (INIS)

In thallium-201 myocardial perfusion scintigraphy, washout rate (WR) has been used for the evaluation of the severity of ischemic heart disease (IHD). The WR was calculated from the polar map (Bull's-eye display) of myocardial perfusion using SPECT. To analyze the abnormality of WR map, we computed the extent and severity scores of WR. Applications of two types of standards, absolute and relative standards from control group (n=16), were compared. The multiple regression analysis showed that the global WR was a function of the severity of coronary artery stenosis and exercise level, i.e. WR (%)=-2.38x(number of stenotic artery)+0.093x(rate-pressure product/100)+19.7(n=62, r=0.63). Thus in evaluating the severity of IHD by absolute WR, the correction of WR was necessary according to the exercise level. Whereas, to evaluate the score of WR abnormality in polar map, the relative standard separated each group with different number of stenotic artery better than absolute standard did. In conclusion, calculation of WR score from relative standard is recommended for the analysis of polar WR map, although absolute global WR is useful for the evaluation of severity of coronary artery disease. (author)

360

Stochastic analysis of heart rate variability and its relation to echocardiography parameters in hypertrophic cardiomyopathy patients  

International Nuclear Information System (INIS)

The heart rate variability of 10 healthy males (age 26 ? 4/+ 3 y) and 49 patients with hypertrophic cardiomyopathy (HCM) (25 males, 24 females, age 29.5 ? 11.5/+ 10.5 y) was studied. We applied Kramers–Moyal expansion to extract the drift and diffusion terms of the Langevin equation for the RR interval time series. These terms may be used for a stochastic reconstruction of the time series and for description of the properties of heart rate variability. New parameters characterizing the diffusion term are proposed: the coefficients of the linear fit to the left (LCF) and right (RCF) branch of the dependence of the diffusion term on the rescaled heart rate. Relations of the new parameters to classical echocardiography parameters were studied. Using the relation between the difference LCF–RCF and the left ventricular systolic diameter, the HCM patients studied were divided into three groups. In addition, comparison of the properties of the heart rate variability in the HCM group with that obtained for the healthy young men showed that the parameter LCF–RCF may be treated as a measure of the effect of HCM on heart rate variability and may have diagnostic value

361

[Afobazole effect on heart rate variability in rats with different behaviors in the "open field" test].  

Science.gov (United States)

The course of cardiovascular diseases is known to depend upon vegetative nervous system condition. The heart rate variability is the quantitative indicator of vegetative nervous system activity. The emotional stress reaction in rats tested in the "open field" was assessed by measuring the heart rate variability, which allowed the chronotropic cardiac function to be studied in detail and showed which part of the vegetative system (either sympathetic or parasympathetic) prevails in animals with different phenotypes of the emotional stress reaction. In rats demonstrating different behaviors in the "open field" test, changes in the heart rate variability were examined under conditions of the emotional stress response development and the treatment with non-benzodiazepine anxiolytic afobazole. It was established that the sympathetic nervous system tone prevails in stress-resistant rats, whereas in non-resistant animals, the parasympathetic system is predominating. In non-resistant rats exposed to stress, the heart rate variability decreased due to reduced power of very low frequencies, in contrast to stress-resistant animals, which showed increased power of very low frequencies. Afobazole was found to increase the heart rate variability in both animal groups. In non-resistant rats, afobazole also raised the vagus tone. PMID:19334509

Kaverina, N V; Popova, E P; Iarkova, M A; Seredenin, S B

2009-01-01

362

Changes in Blood Pressure and Heart Rate during Fixed-Interval Responding in Squirrel Monkeys  

Science.gov (United States)

Episodic and sustained increases in heart rate and mean arterial blood pressure can occur with recurring patterns of schedule-controlled behavior. Most previous studies were conducted under fixed-ratio schedules, which maintained a consistent high rate of responding that alternated with periods of no responding during times when the schedule was…

DeWeese, Jo

2009-01-01

363

Effect of amlodipine and of nifedipine retard on autonomic regulation of heart rate in elderly patients with arterial hypertension  

Directory of Open Access Journals (Sweden)

Full Text Available Aim. To study the effect of the monotherapy with calcium channel blockers (amlodipine, 5 mg/d and nifedipine retard, 40 mg/d on heart rate variability (HRV in elderly hypertensive patients with different rate of biological ageing.Material and methods. 55 male hypertensive patients of 60-86 years with ischemic heart disease and chronic heart failure, class I-III (NYHA, were examined. Biological age was determined by the linear regression. HRVwas determined by cardiointervalography and variation pulsemetry at the rest and in orthostatic test. Patientswere split in to 2 groups (I - normal; II - fast ageing rate and treated with the investigated drugs for 4 weeks. At the baseline and at the end of the study HRV and clinical blood pressure (BP were determined.Results. Normal sympathetic activity and moderate overactivity was observed in patients of I group, and prominent sympathetic overactivity - in patients of II group. Monotherapywith amlodipine in patients of I and II groups improved indices of HRV (variation range, dispersion and stress index and provided target BP reduction.Monotherapywith nifedipine retard in patients of I group elevated variation range, decreased stress index and provided target BP reduction. Sympathetic activity was not changed in patients of the II group. Autonomic regulation was normalized due to amlodipine and nifedipine retard therapy in patients of the both groups.Conclusion. The sympathetic overactivity is observed in elderly hypertensive patients. Monotherapy with calcium blockers improves HRV and provides target BP reduction.

E.D. Golovanova

2008-01-01

364

Changes in Heart Rate Variability Are Associated with Expression of Short-Term and Long-Term Contextual and Cued Fear Memories  

OpenAIRE

Heart physiology is a highly useful indicator for measuring not only physical states, but also emotional changes in animals. Yet changes of heart rate variability during fear conditioning have not been systematically studied in mice. Here, we investigated changes in heart rate and heart rate variability in both short-term and long-term contextual and cued fear conditioning. We found that while fear conditioning could increase heart rate, the most significant change was the reduction in heart ...

Liu, Jun; Wei, Wei; Kuang, Hui; Zhao, Fang; Tsien, Joe Z.

2013-01-01

365

Low doses of caffeine reduce heart rate during submaximal cycle ergometry  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background The purpose of this study was to examine the cardiovascular effects of two low-levels of caffeine ingestion in non habitual caffeine users at various submaximal and maximal exercise intensities. Methods Nine male subjects (19–25 yr; 83.3 ± 3.1 kg; 184 ± 2 cm, underwent three testing sessions administered in a randomized and double-blind fashion. During each session, subjects were provided 4 oz of water and a gelatin capsule containing a placebo, 1.5 mg/kg caffeine, or 3.0 mg/kg caffeine. After thirty minutes of rest, a warm-up (30 Watts for 2 min the pedal rate of 60 rpm was maintained at a steady-state output of 60 watts for five minutes; increased to 120 watts for five minutes and to 180 watts for five minutes. After a 2 min rest the workload was 180 watts for one minute and increased by 30 watts every minute until exhaustion. Heart rate (HR was measured during the last 15-seconds of each minute of submaximal exercise. Systolic blood pressure (BP was measured at rest and during each of the three sub-maximal steady state power outputs. Minute ventilation (VE, Tidal volume (VT, Breathing frequency (Bf, Rating of perceived exertion (RPE, Respiratory exchange ratio (RER, and Oxygen consumption (VO2 were measured at rest and during each minute of exercise. Results Caffeine at 1.5 and 3.0 mg/kg body weight significantly lowered (p E, VT, VO2, RPE, maximal power output or time to exhaustion. Conclusion In non habitual caffeine users it appears that consuming a caffeine pill (1.5 & 3.0 mg/kg at a dose comparable to 1–3 cups of coffee lowers heart rate during submaximal exercise but not at near maximal and maximal exercise. In addition, this caffeine dose also only appears to affect systolic blood pressure at rest but not during cycling exercise.

Wetter Thomas J

2007-10-01

366

Heart Rate Recovery After Exercise and Neural Regulation of Heart Rate Variability in 30-40 Year Old Female Marathon Runners  

OpenAIRE

The aim of the present study was to examine the effects of endurance training on heart rate (HR) recovery after exercise and cardiac autonomic nervous system (ANS) modulation in female marathon runners by comparing with untrained controls. Six female marathon runners (M group) aged 32-40 years and eight age-matched untrained females (C group) performed a maximum-effort treadmill running exercise. Maximal oxygen uptake (VO2max) was measured during the exercise with a gas analyzer connected to ...

Toshio Matsuoka; Harumi Kawase; Ichie Matsumoto; Yoshihiro Kato; Kazuo Oguri; Siqin Bai; Na Du

2005-01-01

367

[Possible applications bisoprolol for heart rate control in young patients with connective tissue dysplasia].  

Science.gov (United States)

To assess the efficacy and safety of bisoprolol to monitor heart rate (HR) in young patients with connective tissue dysplasia (CTD) examined 58 patients (22,3 + 3,47 years, 38 men). Bisoprolol drug was administered at an initial dose of 1.25 mg/day, with a further increase to 2.5 mg/day in 2 weeks, etc. to achieve the level of heart rate 59-69 beats/min. Average effective dose was 7.27 ± 2.08 mg/day. Target heart rate,improvement of health and the pumping function of the heart, reducing the activation of the sympathetic nervous system and of anxiety achieved the absolute majority of patients. During treatment unit observed transient manifestations of general weakness, headache, episodes of vertigo in the selection of the dose, cases of bradycardia and hypotension pathological registered for the time of ingestion. Thus, the use of mandatory bisoprolol gradual careful titration, starting with 1.25 mg/day as a means to control the heart rate in young patients with CTD with sinus tachycardia, the manifestations of autonomic nervous system dysfunction, safely and effectively in relation to adverse orthostatic reactions. PMID:25177888

Nechaeva, G I; Drokina, O V

2014-01-01

368

Multiscale multifractal analysis of heart rate variability recordings with a large number of occurrences of arrhythmia  

Science.gov (United States)

Human heart rate variability, in the form of time series of intervals between heart beats, shows complex, fractal properties. Recently, it was demonstrated many times that the fractal properties vary from point to point along the series, leading to multifractality. In this paper, we concentrate not only on the fact that the human heart rate has multifractal properties but also that these properties depend on the time scale in which the multifractality is measured. This time scale is related to the frequency band of the signal. We find that human heart rate variability appears to be far more complex than hitherto reported in the studies using a fixed time scale. We introduce a method called multiscale multifractal analysis (MMA), which allows us to extend the description of heart rate variability to include the dependence on the magnitude of the variability and time scale (or frequency band). MMA is relatively immune to additive noise and nonstationarity, including the nonstationarity due to inclusions into the time series of events of a different dynamics (e.g., arrhythmic events in sinus rhythm). The MMA method may provide new ways of measuring the nonlinearity of a signal, and it may help to develop new methods of medical diagnostics.

Giera?towski, J.; ?ebrowski, J. J.; Baranowski, R.

2012-02-01

369

Variability of the human heart rate as a diagnostic instrument obtained by mean of a wireless monitor  

Science.gov (United States)

Introduction: Heart rate variability (HRV) is the cyclic measurement of RR intervals between normal beats. Aim: To determine the VFC via a wireless Polar monitor. Material and methods: 100 symptomatic menopausal women were studied for measurements of HRV were I post a Polar RS400 Watch four hrs. Results: Obtained through the fast Fourier transform, the frequency domain HRV low frequency (LF) 0.04-0.15 Hz, high frequency (HF) 0.15-0.4Hz and the ratio LF / HF. Conclusion: obtaining HRV is important for cardiovascular autonomic assessment in menopausal women.

Barajas Mauricio, Sánchez; Hernández González, Martha Alicia; Figueroa Vega, Nicte; Malacara Hernández, Juan Manuel; Fraga Teodoro, Córdova

2014-11-01

370

[Characteristics of the heart rate of emergency physicians in emergency helicopters].  

Science.gov (United States)

The heart rate behaviour of 14 emergency doctors was examined in 50 cases of medical emergency service by helicopter. In addition, the subjective stress experienced by the probands was inquired by means of a questionnaire. The alarm and the landing at the site of the emergency resulted in the most marked heart rate increases; also during the period of approaching the patient, his rescue and care, persistent tachycardia could be observed. Recovery began slowly during the return flight, but even 15 minutes after completion of the emergency task the heart rate was still higher than the original value before the alarm had been sounded. Subjectively the total stress was considered to be generally low in the opinion of the emergency doctors. It seems that unconscious mechanisms of repression prevent the actual realistic recording of physical and emotional stress during the emergency service by helicopter. PMID:1932451

Benzer, A; Niebergall, H; Posch, G; Flora, G

1991-08-01

371

Cardiovascular oscillations at the bedside: early diagnosis of neonatal sepsis using heart rate characteristics monitoring.  

Science.gov (United States)

We have applied principles of statistical signal processing and nonlinear dynamics to analyze heart rate time series from premature newborn infants in order to assist in the early diagnosis of sepsis, a common and potentially deadly bacterial infection of the bloodstream. We began with the observation of reduced variability and transient decelerations in heart rate interval time series for hours up to days prior to clinical signs of illness. We find that measurements of standard deviation, sample asymmetry and sample entropy are highly related to imminent clinical illness. We developed multivariable statistical predictive models, and an interface to display the real-time results to clinicians. Using this approach, we have observed numerous cases in which incipient neonatal sepsis was diagnosed and treated without any clinical illness at all. This review focuses on the mathematical and statistical time series approaches used to detect these abnormal heart rate characteristics and present predictive monitoring information to the clinician. PMID:22026974

Moorman, J Randall; Delos, John B; Flower, Abigail A; Cao, Hanqing; Kovatchev, Boris P; Richman, Joshua S; Lake, Douglas E

2011-11-01

372

Effect of heart rate and myocardial contractile force on coronary resistance.  

Directory of Open Access Journals (Sweden)

Full Text Available The effect of the heart rate and myocardial contractile force on the extravascular resistance to blood flow of the left anterior descending coronary artery (LAD was evaluated in 15 mongrel dogs anesthetized with sodium pentobarbital. The LAD was maximally dilated by intracoronary infusion of adenosine, which precluded the influence of vasomotor tone. Increases in the heart rate and myocardial contractile force decreased coronary blood flow in the absence of a change in coronary perfusion pressure. The changes in mean coronary resistance showed a significant linear relationship to changes in developed tension. The changes in coronary resistance caused by varying the heart rate and contractile force were so small that a normal coronary vascular tree could easily compensate for the increase in resistance. However, it is supposed that with critical stenosis of the vascular tree even a small increase in resistance might cause deleterious effects on coronary blood flow.

Saito,Daiji

1988-12-01

373

Spectral and symbolic analysis of heart rate data during the tilt test  

Science.gov (United States)

Spectral analysis of heart rate sequences is commonly used to investigate neuroauthonomic control of heart rate by means of two indexes, the low and the high frequency power. For tilt test data of normal subjects we compare the spectral indexes with new indexes defined within the framework of symbolic analysis. We define two classes of binary words of length 4: the first class is related to “acceleration” of heart rate and the second class to “stationary behavior.” The new indexes measure the change in frequency of the two classes before and after the tilt. Data analysis of 13 normal subjects shows that the behavior of the new indexes is in agreement with that of spectral ones.

Cammarota, Camillo; Rogora, Enrico

2006-10-01

374

Heart rate variability during head down tilt and lower body negative pressure in the Russian Tschibis.  

Science.gov (United States)

The cardiovascular function in space seems to be normal. However, abnormalities of cardiovascular responses have been found during lower body negative pressure suction in space. The etiology of the cardiovascular deconditioning in space is still unknown. A previous study showed, that short periods of head down tilt (HDT-6 degrees) induce changes in the spectral pattern of heart rate variabilty (HRV) and an increase in the sympathethic activation caused by orthostatic stress. The aim of this study was to test following hypotheses: 1. The dynamic of heart rate variability is different in the head down tilt and supine positions. 2. The application of lower body negative pressure (LBNP) during head down tilt induces similar heart rate variability patterns like the standing position. 3. After short term head down tilt the cardiovascular response to lower body negative pressure stressor is altered. PMID:11538895

Diedrich, A; Drescher, J; Nalishitij, V; Spatenko, J A; Rome, J L; Grüber, W

1995-01-01

375

Heart rate estimation on a beat-to-beat basis via ballistocardiography - a hybrid approach.  

Science.gov (United States)

We present an algorithm for obtaining the heart rate from the signal of a single, contact-less sensor recording the mechanical activity of the heart. This vital parameter is required on a beat-to-beat basis for applications in sleep analysis and heart failure disease management. Our approach bundles information from various sources for first robust estimates. These estimates are further refined in a second step. An unambiguous comparison with the ECG RR-intervals taken as reference is possible for 98.5% of the heart beats. In these cases, a mean absolute error of 17 ms for the inter-beat interval lengths has been achieved, over a test corpus of 20 whole nights. PMID:21097094

Friedrich, David; Aubert, Xavier L; Fuhr, Hartmut; Brauers, Andreas

2010-01-01

376

Heart Rate Variability Classification and Feature Extraction Using Support Vector Machine and PCA: An Overview  

Directory of Open Access Journals (Sweden)

Full Text Available In today’s era Heart Rate Variability becomes an important characteristic to determine the condition of heart. That’s why the calculation of HRV and classification to generate rules is necessary. Human Heart Generates the electrical signal. ECG is used to detect the heart beat. ECG signal contains lots of noise. To classify the signals first to decompose the signals using wavelet transform. Many Mother wavelet are used to denoise the signals. Support Vector Machine is used to classify the denoise signal and recognize pattern for better classification of ECG signal. Various methods have been done using different classification tools like Neural Network, Support Vector Machine, and Wavelet transform. Among them Support Vector Machine is very successful in many research areas such as pattern recognition, bioinformatics, etc. This paper gives Brief Survey on Support Vector Machine and Combination of Wavelet Transform & PCA for better Feature Extraction of ECG signals

Rahul Pitale

2014-01-01

377

Development and preliminary validation of heart rate and breathing rate detection using a passive, ballistocardiography-based sleep monitoring system.  

Science.gov (United States)

Techniques such as ballistocardiography (BCG) that can provide noninvasive long-term physiological monitoring have gained interest due to a growing recognition of adverse effects from poor sleep and sleep disorders. The noninvasive analysis of physiological signals (NAPS) system is a BCG-based monitoring system developed to measure heart rate, breathing rate, and musculoskeletal movement that shows promise as a general sleep analysis tool. Overnight sleep studies were conducted on 40 healthy subjects during a clinical trial at the University of Virginia. The NAPS system's measures of heart rate and breathing rate were compared to ECG, pulse oximetry, and respiratory inductance plethysmography (RIP). The subjects were split into a training dataset and a validation dataset, maintaining similar demographics in each set. The NAPS system accurately detected heart rate, averaged over the prescribed 30-s epochs, to within less than 2.72 beats per minute of ECG, and accurately detected breathing rate, averaged over the same epochs, to within 2.10 breaths per minute of RIP bands used in polysomnography. PMID:19129030

Mack, David C; Patrie, James T; Suratt, Paul M; Felder, Robin A; Alwan, Majd A

2009-01-01

378

Evaluation of the influence of change in heart rate on left ventricular diastolic function indices  

International Nuclear Information System (INIS)

In order to assess the influence of change in heart rate on left ventricular diastolic function indices, ECG gated cardiac pool study was performed in 6 patients with implanted programmable AAI pacemakers. Heart rate was changed by atrial pacing from 50 to 120 beats/min, every 10 beats/min. The filling fraction during first third of diastole (1/3FF), the peak filling rate (PFR), mean first third filling rate (1/3FR-mean) and early filling volume ratio (%EFV), being used as the indices of left ventricular diastolic performance, were assessed. In accordance with increase in heart rate, 1/3FF decreased significantly. PFR were fairly stable from 50 to 80 beats/min, but increased significantly from 90 to 120 beats/min. 1/3FR-mean and %EFV did not change significantly, but 1/3FR-mean showed decreasing tendency and %EFV showed increasing tendency as the heart rate was increased. %EFV was more changeable index than other indices among clinical cases. These results indicate that PFR and 1/3FR-mean were appropriate diastolic phase indices at rest. (author)

379

Blood pressure and heart rate changes in children when they read aloud in school.  

OpenAIRE

The 52 children in the study were recruited from two fifth grade classes in Baltimore city. The blood pressures and heart rates were recorded both at rest and while they read aloud in a classroom setting. A computerized monitoring system was used to measure blood pressures. Rapid and highly significant increases in blood pressure and heart rate were observed when the children read aloud. A total of 84 measurements of 312 systolic and diastolic readings were not within the 95th percentile of n...

Thomas, S. A.; Lynch, J. J.; Friedmann, E.; Suginohara, M.; Hall, P. S.; Peterson, C.

1984-01-01

380

Comparison of formulae for heart rate correction of QT interval in exercise ECGs from healthy children  

OpenAIRE

OBJECTIVE—To investigate the differences in four formulae for heart rate correction of the QT interval in serial ECG recordings in healthy children undergoing a graded exercise test.?SUBJECTS—54 healthy children, median age 9.9 years (range 5.05-14.9 years), subjected to graded physical exercise (on a bicycle ergometer or treadmill) until heart rate reached > 85% of expected maximum for age.?DESIGN—ECG was recorded at baseline, at maximum exercise, and at one, two, four, and six m...

Benatar, A.; Decraene, T.

2001-01-01

381

Comparison of heart rate measured by Polar RS 400 and ECG, validity and repeatability .  

OpenAIRE

Aims: The purpose of this study was to investigate criterion-related validity and test–retest repeatability of the heart rate monitor Polar RS400 versus electrocardiogram (ECG). Methodology: Ten healthy subjects, 19–34 years, performed a cycle ergometer test 5 min on each load (50, 100 and 150 W). Heart rate (HR) was measured with ECG and Polar RS400 and recorded digitally. After at least one hour resting the test was repeated. Major findings: The results showed a significant correlation ...

Engstro?m, E.; Ottosson, E.; Wohlfart, Bjo?rn; Grundstro?m, N.; Wise?n, Anita

2012-01-01

382

Validity and reliability of short-term heart-rate variability from the Polar S810.  

OpenAIRE

PURPOSE: : To assess the validity and the reliability of short-term resting heart-rate variability (HRV) measures obtained using the Polar S810 heart-rate monitor and accompanying software. METHODS: : Measures of HRV were obtained from 5-min R to R wave (RR) interval data for 19 males and 14 females during 10 min of quiet rest on three separate occasions at 1-wk intervals using the Polar S810. Criterion measures of HRV were obtained simultaneously using the CardioPerfect (CP; Medical Graphics...

Nunan, D.; Donovan, G.; Jakovljevic, Dg; Hodges, Ld; Sandercock, Gr; Brodie, Da

2009-01-01

383

Does amiodarone affect heart rate by inhibiting the intracellular generation of triiodothyronine from thyroxine?  

OpenAIRE

The hypothesis that the antiarrhythmic drug amiodarone slows down the heart rate by its inhibitory action on the intracellular conversion of thyroxine (T4) to 3,5,3' triiodothyronine (T3) was investigated. For this purpose we compared the effect of amiodarone with that of another potent inhibitor of the T4----T3 conversion, i.e. the radiographic contrast medium iopanoic acid, on the heart rate of unanaesthetized guinea-pigs. Both amiodarone and, to an even greater extent, iopanoic acid induce...

Lindenmeyer, M.; Spo?rri, S.; Sta?ubli, M.; Studer, A.; Studer, H.

1984-01-01

384

Individually Coded Telemetry: a Tool for Studying Heart Rate and Behaviour in Reindeer Calves  

OpenAIRE

The aim of the study was to test the performance of a silver wire modified version of the coded telemetric heart rate monitor Polar Vantage NV™ (PVNV) and to measure heart rate (HR) in a group of captive reindeer calves during different behaviour. The technical performance of PVNV HR monitors was tested in cold conditions (-30°C) using a pulse generator and the correlation between generated pulse and PVNV values was high (r = 0.9957). The accuracy was tested by comparing the HR obtained w...

Pudas T; Nilsson A; Norberg H; Eloranta E; Säkkinen H

2002-01-01

385

Common multifractality in the heart rate variability and brain activity of healthy humans  

Science.gov (United States)

The influence from the central nervous system on the human multifractal heart rate variability (HRV) is examined under the autonomic nervous system perturbation induced by the head-up-tilt body maneuver. We conducted the multifractal factorization analysis to factor out the common multifractal factor in the joint fluctuation of the beat-to-beat heart rate and electroencephalography data. Evidence of a central link in the multifractal HRV was found, where the transition towards increased (decreased) HRV multifractal complexity is associated with a stronger (weaker) multifractal correlation between the central and autonomic nervous systems.

Lin, D. C.; Sharif, A.

2010-06-01

386

Correlated and Uncorrelated Regions in Heart-Rate Fluctuations during Sleep  

Science.gov (United States)

Healthy sleep consists of several stages: deep sleep, light sleep, and rapid eye movement (REM) sleep. Here we show that these sleep stages can be characterized and distinguished by correlations of heart rates separated by n beats. Using the detrended fluctuation analysis (DFA) up to fourth order we find that long-range correlations reminiscent to the wake phase are present only in the REM phase. In the non-REM phases, the heart rates are uncorrelated above the typical breathing cycle time, pointing to a random regulation of the heartbeat during non-REM sleep.

Bunde, Armin; Havlin, Shlomo; Kantelhardt, Jan W.; Penzel, Thomas; Peter, Jörg-Hermann; Voigt, Karlheinz

2000-10-01

387

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

OpenAIRE

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...

MICHAIL KATSIKADELIS; THEOPHILOS PILIANIDIS; NIKOLAOS MANTZOURANIS; IOANNIS FATOUROS; NIKOLAOS AGELOUSIS

2014-01-01

388

DIETARY SODIUM EFFECTS ON HEART RATE VARIABILITY IN SALT-SENSITIVITY OF BLOOD PRESSURE  

OpenAIRE

High dietary sodium intake is a risk factor for hypertension, and heart rate variability (HRV) is decreased in hypertension. Effects of dietary sodium intake on HRV of normotensive persons have not, however, been investigated to date. The present study examined effects of low and high sodium diets on blood pressure, heart rate, and HRV in 36 healthy, normotensive women, ages 40–70. Each was placed on a low sodium diet for six days followed by a high sodium diet for six days. High salt diet ...

Jd, Mcneely; Bg, Windham; Anderson

2007-01-01

389

Quantifying Exertion Level During Exercise Stress Testing Using Percentage of Age-Predicted Maximal Heart Rate, Rate Pressure Product, and Perceived Exertion  

OpenAIRE

OBJECTIVE: To determine if the attainment of at least 85% of age-predicted maximal heart rate (APMHR), using the equation 220 – age, and/or at least 25,000 as the product of maximal heart rate and systolic blood pressure (rate pressure product, RPP) is an accurate indicator of exertion level during exercise stress testing.

Pinkstaff, Sherry; Peberdy, Mary Ann; Kontos, Michael C.; Finucane, Sheryl; Arena, Ross

2010-01-01

390

Evaluation of therapy for dilated cardiomyopathy with heart failure by iodine-123 metaiodobenzyl-guanidine imaging. Comparison with heart rate variability power spectral analysis  

Energy Technology Data Exchange (ETDEWEB)

The relationship between the myocardial uptake of iodine-123 metaiodobenzylguanidine ({sup 123}I-MIBG) and heart rate variability parameters has not been determined. This study determined the relationship between the change in myocardial uptake of {sup 123}I-MIBG and improvement in left ventricular function after treatment, to determine the usefulness of {sup 123}I-MIBG imaging to assess the effect of therapy on heart failure due to dilated cardiomyopathy (DCM). {sup 123}I-MIBG imaging and power spectral analysis of heart rate variability were performed before and after treatment in 17 patients with heart failure due to DCM. The following parameters were compared before and after treatment: New York Heart Association (NYHA) functional class, radiographic cardiothoracic ratio (CTR), blood pressure, echocardiographic data (left ventricular end-systolic (LVDs) and end-diastolic (LVDd) diameters, left ventricular ejection fraction (LVEF)), plasma concentrations of norepinephrine and epinephrine, heart rate variability power spectral analysis data (mean low frequency (MLF) and high frequency power (MHF)) and the myocardium to mediastinum activity ratio (MYO/M) obtained in early and late images, and washout rate calculated by anterior planar imaging of {sup 123}I-MIBG. The NYHA functional class, LVEF, LVDs, CTR, MLF and MHF improved after treatment. Early MYO/M and late MYO/M improved after treatment. The rate of increase in late MYO/M was positively correlated with the rate of improvement of LVEF after treatment. Furthermore, the late MYO/M was negatively correlated with MLF. Washout rate revealed no correlation with hemodynamic parameters. These findings suggest that late MYO/M is more useful than washout rate to assess the effect of treatment on heart failure due to DCM. Furthermore, the {sup 123}I-MIBG imaging and heart rate variability parameters are useful to assess the autonomic tone in DCM with heart failure. (author)

Li, Shou-lin; Ikeda, Jun; Takita, Tamotsu; Sekiguchi, Yohei; Demachi, Jun; Chikama, Hisao; Goto, Atsushi; Shirato, Kunio [Tohoku Univ., Sendai (Japan). School of Medicine

1998-11-01

391

Mouse Heart Rate in a Human: Diagnostic Mystery of an Extreme Tachyarrhythmia  

OpenAIRE

We report telemetry recording of an extreme non-fatal tachyarrhythmia noted in a hospitalized quadriplegic male with history of atrial fibrillation where the average ventricular conduction rate was found to be about 600 beats per minute and was associated with transient syncope. A medical literature review suggests that the fastest human ventricular conduction rate reported to date in a tachyarrhythmia is 480 beats per minute. We therefore report the fastest human heart rate noted in a tachya...

Chhabra, Lovely; Goel, Narender; Prajapat, Laxman; Spodick, David H.; Goyal, Sanjeev

2012-01-01

392

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

OpenAIRE

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 hear...

Raphael Rodrigues Perim; Gabriel Ruiz Signorelli; Jonathan Myers; Ross Arena; Claudio Gil Soares Araújo

2011-01-01

393

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

OpenAIRE

AIM: Physical exercise has been associated with heart rate and blood pressure in observational studies and individual clinical trails. The purpose of these study was to asses heart rate and blood pressure changes in healthy adult women students before and after training during walking and running. MATERIALS and METHODS: Fourty healthy women were taken as the subjects. Heart rate and blood pressure recorded before and after training during waking and running. In these study 1600 me...

Kaarna Munisekhar; Muralidhar, M. V.; Madras Venkatachalam; Dalavai Hemalatha

2014-01-01

394

Optimal image reconstruction phase at low and high heart rates in dual-source CT coronary angiography  

OpenAIRE

The purpose of this study was to determine the cardiac phase having the highest coronary sharpness for low and high heart rate patients scanned with dual source CT (DSCT) and to compare coronary image sharpness over different cardiac phases. DSCT coronary CT scans for 30 low heart rate (? 70 beats per minute- bpm) and 30 high heart rate (>70 bpm) patients were reconstructed into different cardiac phases, starting at 30% and increasing at 5% increments until 70%. A blinded observer graded im...

Araoz, Philip A.; Kirsch, Jacobo; Primak, Andrew N.; Braun, Natalie N.; Saba, Osama; Williamson, Eric E.; Harmsen, W. Scott; Mandrekar, Jayawant N.; Mccollough, Cynthia H.

2009-01-01

395

Association of resting heart rate with carotid and aortic arterial stiffness: Multi-Ethnic Study of Atherosclerosis (MESA)  

OpenAIRE

Resting heart rate is an easily measured, non-invasive vital sign that is associated with cardiovascular disease events. The pathophysiology of this association is not known. We investigated the relationship between resting heart rate and stiffness of the carotid (a peripheral artery) and the aorta (a central artery) in an asymptomatic multi-ethnic population. Resting heart rate was recorded at baseline in the Multi-Ethnic Study of Atherosclerosis (MESA). Distensibility was used as a measure ...

Whelton, Seamus P.; Blankstein, Ron; Al–mallah, Mouaz H.; Lima, Joao A. C.; Bluemke, David A.; Hundley, W. Gregory; Polak, Joseph F.; Blumenthal, Roger S.; Nasir, Khurram; Blaha, Michael J.

2013-01-01

396

Autonomic function in sleep apnea patients: increased heart rate variability except during REM sleep in obese patients.  

Science.gov (United States)

The objective of this study was to examine heart rate variability (HRV) among sleep stages in obstructive sleep apnea (OSA) patients. The study was retrospective within subjects and examined the sleep stages and HRV in relation to OSA, age, body mass index (BMI), and sex. Data collected during diagnostic polysomnograms were used in this study. There were 105 clinical patients undergoing polysomnography for suspected OSA. We sampled the electrocardiogram (ECG) from wakefulness, stage 2, and REM sleep and analyzed for frequency domain HRV. Sampled epochs were free of apnea and arousals. Heart rate variability decreased with age. Total frequency variability (TF) and low frequency variability (LF) in wakefulness and REM sleep increased as apnea severity increased. Measures of TF, LF, and the LF/HF ratio were greatest in REM sleep. There was less LF and TF in Stage REM sleep in patients with higher BMI. In conclusion, the decrease in HRV with aging is a robust finding that occurs even in a clinical sleep apnea population. However, apnea does not mimic aging effects on the heart because HRV increased as apnea severity increased. The decrease in HRV during REM sleep in the obese apnea patients suggests the possibility of an autonomic dysfunction in this subgroup. PMID:17171554

Reynolds, Erica B; Seda, Gilbert; Ware, J C; Vinik, Aaron I; Risk, Marcelo R; Fishback, Nancy F

2007-03-01

397

E-bra with nanosensors, smart electronics and smart phone communication network for heart rate monitoring  

Science.gov (United States)

Heart related ailments have been a major cause for deaths in both men and women in United States. Since 1985, more women than men have died due to cardiac or cardiovascular ailments for reasons that are not well understood as yet. Lack of a deterministic understanding of this phenomenon makes continuous real time monitoring of cardiovascular health the best approach for both early detection of pathophysiological changes and events indicative of chronic cardiovascular diseases in women. This approach requires sensor systems to be seamlessly mounted on day to day clothing for women. With this application in focus, this paper describes a e-bra platform for sensors towards heart rate monitoring. The sensors, nanomaterial or textile based dry electrodes, capture the heart activity signals in form Electrocardiograph (ECG) and relay it to a compact textile mountable amplifier-wireless transmitter module for relay to a smart phone. The ECG signal, acquired on the smart phone, can be transmitted to the cyber space for post processing. As an example, the paper discusses the heart rate estimation and heart rate variability. The data flow from sensor to smart phone to server (cyber infrastructure) has been discussed. The cyber infrastructure based signal post processing offers an opportunity for automated emergency response that can be initiated from the server or the smartphone itself. Detailed protocols for both the scenarios have been presented and their relevance to the present emergency healthcare response system has been discussed.

Varadan, Vijay K.; Kumar, Prashanth S.; Oh, Sechang; Mathur, Gyanesh N.; Rai, Pratyush; Kegley, Lauren

2011-04-01

398

Estimation of organ-absorbed radiation doses during 64-detector CT coronary angiography using different acquisition techniques and heart rates: a phantom study  

International Nuclear Information System (INIS)

Background: Though appropriate image acquisition parameters allow an effective dose below 1 mSv for CT coronary angiography (CTCA) performed with the latest dual-source CT scanners, a single-source 64-detector CT procedure results in a significant radiation dose due to its technical limitations. Therefore, estimating the radiation doses absorbed by an organ during 64-detector CTCA is important. Purpose: To estimate the radiation doses absorbed by organs located in the chest region during 64-detector CTCA using different acquisition techniques and heart rates. Material and Methods: Absorbed doses for breast, heart, lung, red bone marrow, thymus, and skin were evaluated using an anthropomorphic phantom and radiophotoluminescence glass dosimeters (RPLDs). Electrocardiogram (ECG)-gated helical and ECG-triggered non-helical acquisitions were performed by applying a simulated heart rate of 60 beats per minute (bpm) and ECG-gated helical acquisitions using ECG modulation (ECGM) of the tube current were performed by applying simulated heart rates of 40, 60, and 90 bpm after placing RPLDs on the anatomic location of each organ. The absorbed dose for each organ was calculated by multiplying the calibrated mean dose values of RPLDs with the mass energy coefficient ratio. Results: For all acquisitions, the highest absorbed dose was observed for the heart. When the helical and non-helical acquisitions were performed by applying a simulated heart rate of 60 bpm, the absorbed doses heart rate of 60 bpm, the absorbed doses for heart were 215.5, 202.2, and 66.8 mGy for helical, helical with ECGM, and non-helical acquisitions, respectively. When the helical acquisitions using ECGM were performed by applying simulated heart rates of 40, 60, and 90 bpm, the absorbed doses for heart were 178.6, 139.1, and 159.3 mGy, respectively. Conclusion: ECG-triggered non-helical acquisition is recommended to reduce the radiation dose. Also, controlling the patients' heart rate appropriately during ECG-gated helical acquisition with ECGM is crucial

399

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

Scientific Electronic Library Online (English)

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 percentag [...] e 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

Vitor Oliveira, Carvalho; Guilherme Veiga, Guimarães; Edimar Alcides, Bocchi.

400

Heart rate reduction for 36 months with ivabradine reduces left ventricular mass in cardiac allograft recipients: a long-term follow-up study  

Directory of Open Access Journals (Sweden)

Full Text Available Andreas O Doesch,1 Susanne Mueller,1 Christian Erbel,1 Christian A Gleissner,1 Lutz Frankenstein,1 Stefan Hardt,1 Arjang Ruhparwar,2 Philipp Ehlermann,1 Thomas Dengler,3 Hugo A Katus1 1Department of Cardiology, 2Department of Cardiovascular Surgery, University of Heidelberg, Heidelberg, 3SLK Plattenwald Hospital, Bad Friedrichshall, Germany Background: Due to graft denervation, sinus tachycardia is a common problem after heart transplantation, underlining the importance of heart rate control without peripheral effects. However, long-term data regarding the effects of ivabradine, a novel If channel antagonist, are limited in patients after heart transplantation. Methods: In this follow-up analysis, the resting heart rate, left ventricular mass indexed to body surface area (LVMI, tolerability, and safety of ivabradine therapy were evaluated at baseline and after 36 months in 30 heart transplant recipients with symptomatic sinus tachycardia versus a matched control group. Results: During the study period, ivabradine medication was stopped in three patients (10% of total. Further analysis was based on 27 patients with 36 months of drug intake. The mean patient age was 53.3±11.3 years and mean time after heart transplantation was 5.0±4.8 years. After 36 months, the mean ivabradine dose was 12.0±3.4 mg/day. Resting heart rate was reduced from 91.0±10.7 beats per minute before initiation of ivabradine therapy (ie, baseline to 81.2±9.8 beats per minute at follow-up (P=0.0006. After 36 months of ivabradine therapy, a statistically significant reduction of LVMI was observed (104.3±22.7 g at baseline versus 93.4±18.4 g at follow-up, P=0.002. Hematologic, renal, and liver function parameters remained stable during ivabradine therapy. Except for a lower mycophenolate mofetil dose at follow-up (P=0.02, no statistically significant changes in immunosuppressive drug dosage or blood levels were detected. No phosphenes were observed during 36 months of ivabradine intake despite active inquiry. Conclusion: In line with previously published 12-month data, heart rate reduction with ivabradine remained effective and safe in chronic stable patients after heart transplantation, and also during 36-month long-term follow-up. Further, a significant reduction of LVMI was observed only during ivabradine therapy. Therefore, ivabradine may have a sustained long-term beneficial effect with regard to left ventricular remodeling in heart transplant patients. Keywords: heart transplantation, heart rate control, ivabradine, left ventricular mass

Doesch AO

2013-11-01

401

Central exogenous nitric oxide decreases cardiac sympathetic drive and improves baroreflex control of heart rate in ovine heart failure.  

Science.gov (United States)

Heart failure (HF) is associated with increased cardiac and renal sympathetic drive, which are both independent predictors of poor prognosis. A candidate mechanism for the centrally mediated sympathoexcitation in HF is reduced synthesis of the inhibitory neuromodulator nitric oxide (NO), resulting from downregulation of neuronal NO synthase (nNOS). Therefore, we investigated the effects of increasing the levels of NO in the brain, or selectively in the paraventricular nucleus of the hypothalamus (PVN), on cardiac sympathetic nerve activity (CSNA) and baroreflex control of CSNA and heart rate in ovine pacing-induced HF. The resting level of CSNA was significantly higher in the HF than in the normal group, but the resting level of RSNA was unchanged. Intracerebroventricular infusion of the NO donor sodium nitroprusside (SNP; 500 ?g · ml(-1)· h(-1)) in conscious normal sheep and sheep in HF inhibited CSNA and restored baroreflex control of heart rate, but there was no change in RSNA. Microinjection of SNP into the PVN did not cause a similar cardiac sympathoinhibition in either group, although the number of nNOS-positive cells was decreased in the PVN of sheep in HF. Reduction of endogenous NO with intracerebroventricular infusion of N(?)-nitro-l-arginine methyl ester decreased CSNA in normal but not in HF sheep and caused no change in RSNA in either group. These findings indicate that endogenous NO in the brain provides tonic excitatory drive to increase resting CSNA in the normal state, but not in HF. In contrast, exogenously administered NO inhibited CSNA in both the normal and HF groups via an action on sites other than the PVN. PMID:24848361

Ramchandra, Rohit; Hood, Sally G; May, Clive N

2014-08-01

402

Assessment of image quality of 64-row Dual Source versus Single Source CT coronary angiography on heart rate: A phantom study  

Energy Technology Data Exchange (ETDEWEB)

Purpose: To assess the influence of temporal resolution on image quality of computed tomographic (CT) coronary angiography by comparing 64-row Dual Source CT (DSCT) and Single Source CT (SSCT) at different heart rates. Methods: An anthropomorphic moving heart phantom was scanned at rest, and at 50 beats per minute (bpm) up to 110 bpm, with intervals of 10 bpm. 3D volume rendered images and curved multi-planar reconstructions (MPRs) were acquired and image quality of the coronary arteries was rated on a 5-points scale (1 = poor image quality with many artefacts, 5 = excellent image quality) for each heart rate and each scanner by 3 observers. Paired sample t-test and Wilcoxon Signed Ranks test were used to assess clinically relevant differences between both modalities. Results: The mean image quality scores at 70, 100 and 110 bpm were significantly higher for DSCT compared to SSCT. The overall mean image quality scores for DSCT (4.2 {+-} 0.6) and SSCT (3.0 {+-} 1.1) also differed significantly (p < 0.001). Conclusion: These initial results show a clinically relevant overall higher image quality for DSCT compared to SSCT, especially at heart rates of 70, 100 and 110 bpm. With its comparatively high image quality and low radiation dose, DSCT appears to be the method of choice in CT coronary angiography at heart rates above 70 bpm.

Dikkers, R. [Department of Radiology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, P.O. Box 30001, 9700 RB Groningen (Netherlands)], E-mail: r.dikkers@rad.umcg.nl; Greuter, M.J.W. [Department of Radiology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, P.O. Box 30001, 9700 RB Groningen (Netherlands)], E-mail: m.j.w.greuter@rad.umcg.nl; Kristanto, W. [Department of Radiology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, P.O. Box 30001, 9700 RB Groningen (Netherlands)], E-mail: w.kristanto@rad.umcg.nl; Ooijen, P.M.A. van [Department of Radiology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, P.O. Box 30001, 9700 RB Groningen (Netherlands)], E-mail: p.m.a.van.ooyen@rad.umcg.nl; Sijens, P.E. [Department of Radiology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, P.O. Box 30001, 9700 RB Groningen (Netherlands)], E-mail: p.e.sijens@rad.umcg.nl; Willems, T.P. [Department of Radiology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, P.O. Box 30001, 9700 RB Groningen (Netherlands)], E-mail: t.p.willems@rad.umcg.nl; Oudkerk, M. [Department of Radiology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, P.O. Box 30001, 9700 RB Groningen (Netherlands)], E-mail: m.oudkerk@rad.umcg.nl

2009-04-15

403

Assessment of image quality of 64-row Dual Source versus Single Source CT coronary angiography on heart rate: A phantom study  

International Nuclear Information System (INIS)

Purpose: To assess the influence of temporal resolution on image quality of computed tomographic (CT) coronary angiography by comparing 64-row Dual Source CT (DSCT) and Single Source CT (SSCT) at different heart rates. Methods: An anthropomorphic moving heart phantom was scanned at rest, and at 50 beats per minute (bpm) up to 110 bpm, with intervals of 10 bpm. 3D volume rendered images and curved multi-planar reconstructions (MPRs) were acquired and image quality of the coronary arteries was rated on a 5-points scale (1 = poor image quality with many artefacts, 5 = excellent image quality) for each heart rate and each scanner by 3 observers. Paired sample t-test and Wilcoxon Signed Ranks test were used to assess clinically relevant differences between both modalities. Results: The mean image quality scores at 70, 100 and 110 bpm were significantly higher for DSCT compared to SSCT. The overall mean image quality scores for DSCT (4.2 ± 0.6) and SSCT (3.0 ± 1.1) also differed significantly (p < 0.001). Conclusion: These initial results show a clinically relevant overall higher image quality for DSCT compared to SSCT, especially at heart rates of 70, 100 and 110 bpm. With its comparatively high image quality and low radiation dose, DSCT appears to be the method of choice in CT coronary angiography at heart rates above 70 bpm.

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Spectral analysis of heart rate fluctuations and optimum thermal management for low birth weight infants.  

Science.gov (United States)

Spectral analysis of heart rate variability is studied in 10 healthy growing premature infants to investigate the changes in autonomic balance achieved as a function of changes in skin temperature. Heart rate is obtained from ECG recordings and the power spectrum of beat-to-beat heart rate fluctuations is computed. The infants maintain mean rectal temperature within 36.3-37.2 degrees C, while skin temperature changes. The respiratory rate does not change at the different servocontrol set points. Heart rate is found to increase slightly, but consistently. The low-frequency band (0.02-0.2 Hz), reflecting the interplay of the sympathetic and parasympathetic tone and known to be maximum at the thermoneutral zone, is maximum at 35.5 and 36 degrees C and decreases gradually to a lower level at a servocontrol temperature of 36.5-37 degrees C. The high-frequency band (0.2-2.0 Hz), coinciding with the respiratory peak and reflecting parasympathetic activity, is significantly elevated at 36 degrees C (p balance and possibly reflecting the most comfortable conditions, occurs at 36 degrees C, although the differences are not statistically significant. Servocontrol skin temperature may thus be adapted, and possibly selected at 36 degrees C for growing premature infants in an attempt to achieve thermal comfort and more balanced autonomic activity. PMID:9538537

Davidson, S; Reina, N; Shefi, O; Hai-Tov, U; Akselrod, S

1997-11-01

405

Effects of radiation emitted from mobile phones on short- term heart rate variability parameters  

Directory of Open Access Journals (Sweden)

Full Text Available Objective: In this study, the effects of radiation emitted from mobile phone (MP on heart rate variability (HRV which is accepted a non-invasive indicator of autonomic nervous system (ANS were investigated with considering the deficiency of previous studies. Methods: A randomized controlled study has been designed and utilized with 30 young and healthy volunteers. During the experiment that had three periods, the electrocardiogram (ECG and respiration signals were recorded and MP was attached to subjects’ right ear with a bone. Ten subjects selected randomly were exposed to high -level radiation during the second period (Experimental Group 1. Ten of others were exposed during the third period with maximum level radiation (Experimental Group 2. Ten records were also made while MP was closed as a control. Short -term HRV parameters were obtained and repeated measures ANOVA and suitable post-hoc tests applied to the results. Results: According to the results of the repeated measures ANOVA; there were no significant main effects of groups. However, there were some significant differences in measuring time periods and groups*period interactions. The post-hoc tests showed that mean R to R interval and HF power are significantly changed by maximum radiation emitted from MP. Conclusion: Due to the radiation emitted from MPs at maximum power, some changes may occur in HRV parameters that are associated with increased parasympathetic activity. But, the level of these changes is similar to daily activities as excitement, and stand up.

Derya Y?lmaz

2012-08-01

406

Heart rate is associated with markers of fatty acid desaturation: the GOCADAN study  

Directory of Open Access Journals (Sweden)

Full Text Available Objectives: To determine if heart rate (HR is associated with desaturation indexes as HR is associated with arrhythmia and sudden death. Study design: A community based cross-sectional study of 1214 Alaskan Inuit. Methods: Data of FA concentrations from plasma and red blood cell membranes from those ?35 years of age (n =?819 were compared to basal HR at the time of examination. Multiple linear regression with backward stepwise selection was employed to analyze the effect of the desaturase indexes on HR, after adjustment for relevant covariates. Results: The ?5 desaturase index (?5-DI measured in serum has recently been associated with a protective role for cardiovascular disease. This index measured here in plasma and red blood cells showed a negative correlation with HR. The plasma stearoyl-CoA-desaturase (SCD index, previously determined to be related to cardiovascular disease (CVD mortality, on the other hand, was positively associated with HR, while the ?6 desaturase index (?6-DI had no significant effect on HR. Conclusion: Endogenous FA desaturation is associated with HR and thereby, in the case of SCD, possibly with arrhythmia and sudden death, which would at least partially explain the previously observed association between cardiovascular mortality and desaturase activity.

Sven O.E. Ebbesson

2012-03-01

407

Determination of anaerobic threshold through heart rate and near infrared spectroscopy in elderly healthy men  

Scientific Electronic Library Online (English)

Full Text Available BACKGROUND: Aging leads to low functional capacity and this can be reversed by safe and adequate exercise prescription. OBJECTIVE: The aim of this study was to identify the anaerobic threshold (AT) obtained from the V-slope method as well as visual inspection of oxyhemoglobin ( O2Hb) and deox [...] yhemoglobin (HHb) curves and compare findings with the heteroscedastic (HS) method applied to carbon dioxide production ( CO2), heart rate (HR), and HHb data in healthy elderly men. A secondary aim was to assess the degree of agreement between methods for AT determination. METHOD: Fourteen healthy men (61.4±6.3 years) underwent cardiopulmonary exercise testing (CPX) on a cycle ergometer until physical exhaustion. Biological signals collected during CPX included: ventilatory and metabolic variables; spectroscopy quasi-infrared rays - NIRS; and HR through a cardio-frequency meter. RESULTS: We observed temporal equivalence and similar values of power (W), absolute oxygen consumption (O2 - mL/min), relative O2 ( mL.Kg - 1.min -1), and HR at AT by the detection methods performed. In addition, by the Bland-Altman plot, HR confirmed good agreement between the methods with biases between -1.3 and 3.5 beats per minute. CONCLUSIONS: (i) all detection methods were sensitive in identifying AT, including the HS applied to HR and (ii) the methods showed a good correlation in the identification of AT. Thus, these results support HR as valid and readily available parameter in determining AT in healthy elderly men.

Michel S., Reis; Danilo C., Berton; Ross, Arena; Aparecida M., Catai; Jose A., Neder; Audrey, Borghi-Silva.

2013-10-01

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Effect of Tiotropium on Heart Rate Variability in Stable Chronic Obstructive Pulmonary Disease Patients.  

Science.gov (United States)

Abstract Background: The chronic use of the long-acting anticholinergic agent, tiotropium, in chronic obstructive pulmonary disease (COPD) has been linked in some reports to an increase in adverse cardiovascular effects. Decreased heart rate variability (HRV) is a condition seen in COPD patients that has also been linked to poor cardiovascular outcome. We aimed in this study to investigate changes in HRV caused by tiotropium administration to COPD patients in order to determine whether changes occurred that might contribute to an increase in adverse cardiovascular events. Methods: Seventy patients with moderate-to-severe stable COPD were treated with once-daily dosing of tiotropium (two puffs of Spiriva Respimat, 2.5??g solution) for 3 months. HRV, pulmonary function, and quality of life were measured before and after 1 and 3 months of therapy. Results: Pulmonary function and quality of life improved significantly, after both 1 and 3 months of therapy. No significant change in HRV parameters occurred, except for a significant decrease in the high-frequency and increase in the low-frequency component of HRV at the 1-month assessment. Conclusion: Changes in HRV caused by tiotropium use are not sufficient to explain a possible increase in adverse cardiovascular events. PMID:24840562

Wu, Yao-Kuang; Huang, Chun-Yao; Yang, Mei-Chen; Huang, Guo-Liang; Chen, Sin-Yi; Lan, Chou-Chin

2014-05-19

409

Incident solar radiation and coronary heart disease mortality rates in Europe  

International Nuclear Information System (INIS)

The reported low mortality rate from coronary heart disease in Portugal, Spain, Italy, Greece, and France, to a lesser extent, has been attributed in numerous nutritional studies to the consumption of a Mediterranean-type diet. There are still many unresolved issues about the direct causal effect of the Mediterranean dieta