HOFMANN, P., S. P. VON DUVILLARD, F-J. SEIBERT, R. POKAN, M. WONISCH, L. M. LEMURA, and G. SCHWABERGER. %HRmax target heartrate is dependent on heartrateperformance curve deflection. Med. Sci. Sports Exerc., Vol. 33, No. 10, 2001, pp. 1726 -1731. The percent of maximal heartrate (%HRmax) model is widely used to determine training intensities in healthy subjects
PETER HOFMANN; SERGE P. VON DUVILLARD; FRANZ-JOSEF SEIBERT; ROCHUS POKAN; MANFRED WONISCH; LINDA M. LEMURA
ORIGINAL ARTICLE Correlation between heartrate and performance during Olympic windsurfing of this study was to examine the heartrate (HR) response to Olympic windsurfing competition and to check correlation between the highest racing HR (%HRreserve) of each athlete and the sec- ond ventilatory threshold
Numerous studies have shown that high heartrate is prospectively related to the development of atherosclerosis and of cardiovascular events. This relationship has been observed in the general population, in elderly subjects, in hypertensive cohorts, and in patients with myocardial infarction or heart failure. There is still debate over whether the association between fast heartrate and cardiovascular mortality is
Measures heartrates of both anxious and nonanxious speakers under both high- and low-intensity conditions. Finds that heartrates of anxious speakers were significantly higher than those of nonanxious speakers when both performed under low-intensity conditions but that heartrates were not different for anxious and nonanxious speakers when
Three adult stutterers who displayed a preexperimental pattern of consistent expectation and occurrence of stuttering were studied in a single-subject design. Multiple linear regression analyses led to the conclusion that cognitive (signalled) expectancy was predictive of stuttering for two of the subjects. The third subject evidenced essentially no relationship between signalled expectancy and disfluent performance. For two subjects, neither mean heartrate nor heartrate variability was predictive of speech performance. For the third subject, mean heartrate was predictive but heartrate variability was not. For two subjects, there was essentially no relationship between the measured physiologic variables and cognitive expectancy. However, for the third subject both mean heartrate and heartrate variability were significantly predictive of cognitive expectancy. These results suggest that adult stutterers should not be viewed as a homogeneous group with respect to preutterance activity that is either cognitive or physiologic. The relationship between preutterance heartrate, heartrate variability, and expectancy responses and between these preutterance variables and subsequent stuttering appears to be individualistic. PMID:6645463
Eighteen volunteer female subjects received preliminary instruction in a simple gymnastics bench sequence. They were then given a pre?intervention test on a bench at ground level. Self?reported distress, an independent observer's ratings of distress and heartrates were monitored immediately prior to performance of the sequence. Performances were also videotaped and formally scored by a qualified gymnastics judge. Subjects were
In this activity about heart health (on page 27 of the PDF), learners measure their heartrates after a variety of physical activities and compare the results with their resting heartrates, and with the heartrates of other learners in their groups. Learners also make predictions about their pulse rates. This lesson guide includes background information, setup and management tips, extension ideas, information about the heart in space and a handout.
Tharp, Barbara Z.; Erdmann, Deanne B.; Matyas, Marsha L.; Mcneel, Ronald L.; Moreno, Nancy P.
Reduced heartrate variability is a strong predictor of cardiovascular risk factors, cardiovascular events, and mortality and thus may be associated with cognitive neurodegeneration. Yet, this has been relatively unexplored, particularly in minority populations with high cardiovascular burden. We used data from the Sacramento Area Latino Study on Aging to examine the cross-sectional association of reduced heartrate variability with cognitive function among elderly Mexican Americans. A total of 869 participants (mean age, 75 years; 59% women) had their 6-minute heartrate variability measured using an ECG monitor and respiration pacer in response to deep breathing. We used the mean circular resultant, known as R bar, as a measure of heartrate variability and categorized it into quartiles (Q1 to Q4 of R bar: reduced to high heartrate variability). Cognitive function was assessed using the modified Mini-Mental State Examination, a 100-point test of global cognitive function, and the Spanish and English verbal learning test, a 15-point test of verbal memory recall. In fully adjusted linear regression models, participants in quartile 1 had a 4-point lower modified Mini-Mental State Examination score (P<0.01), those in quartile 2 had a 2-point lower score (P=0.04), and those in quartile 3 had a 1-point lower score (P=0.35) compared with those in the highest quartile of R bar. Reduced R bar was not associated with verbal memory. Our results suggest that reduced heartrate variability is associated with worse performance on the test of global cognitive function, above and beyond traditional cardiovascular risk factors. PMID:24144650
Zeki Al Hazzouri, Adina; Haan, Mary N; Deng, Yingzi; Neuhaus, John; Yaffe, Kristine
... My Saved Articles » My ACS » + - Text Size Target HeartRate Calculator Compute your best workout Enter your age ... is your age? years. How to Check Your HeartRate Right after you stop exercising, take your pulse: ...
Learning on the basis of outcome feedback shows pronounced developmental changes, however, much is still unknown about its underlying processes. In the current study, we aimed at decomposing how value updating, feedback monitoring and executing behavioral control contribute to children's probabilistic feedback learning. Children (ages 8-9), young adolescents (ages 11-13) and young adults (ages 18-24), performed two probabilistic feedback tasks: one required building a value representation on the basis of feedback (noninformed task), while in the other value representations were explicitly presented (informed task). Heart-rate was recorded to augment performance measures of feedback processing. We observed substantial developmental differences in heart-rate responses toward feedback in the noninformed task. Adult's heart-rate slowed more to negative compared to positive feedback relative to the children and young adolescents. In contrast, in the informed task all age groups showed larger heart-rate slowing toward negative compared to positive feedback. These results indicate that children are not impaired in monitoring probabilistic feedback per se, but have a specific deficit in building a task-appropriate value representation on the basis of probabilistic feedback. PMID:23352569
Van Duijvenvoorde, Anna C K; Jansen, Brenda R J; Griffioen, Edmee S; Van der Molen, Maurits W; Huizenga, Hilde M
This study investigated the effect of 30% oxygen administration on verbal cognitive performance, blood oxygen saturation, and heartrate. Five male (24.6(±0.9) years) and five female (22.2(±1.9) years) college students were selected as the subjects for this study. Two psychological tests were developed to measure the performance level of verbal cognition. The experiment consisted of two runs: one was a
The aim of the present study was to verify the validity of using exercise heartrate (HRex), HR recovery (HRR) and post-exercise\\u000a HR variability (HRV) during and after a submaximal running test to predict changes in physical performance over an entire\\u000a competitive season in highly trained young soccer players. Sixty-five complete data sets were analyzed comparing two consecutive\\u000a testing sessions
M. Buchheit; M. B. Simpson; H. Al Haddad; P. C. Bourdon; A. Mendez-Villanueva
This study examined the effects of two short physical training programs on various parameters of heartrate variability (HRV)\\u000a and on executive performance in older people. Twenty-four sedentary men and women aged 6578 years were randomly assigned\\u000a to an aerobic exercise program or a stretching program three times a week for 12 weeks. Resting HRV was measured in time and\\u000a frequency domains
Cédric T. Albinet; Geoffroy Boucard; Cédric A. Bouquet; Michel Audiffren
Rats trained to bar press for food were sleep-deprived in increasing 12-hr. periods up to 48 hr. Heartrate was found to increase monotonically with hours of sleep deprivation. Higher heartrates under conditions of high-rate bar pressing appeared to reflect an interaction between cue stimulation and the internal deprivation effects; i.e., heartrate was higher when the cues were
Under a NASA grant, Dr. Robert M. Davis and Dr. William M. Portnoy came up with a new type of electrocardiographic electrode that would enable long term use on astronauts. Their invention was an insulated capacitive electrode constructed of a thin dielectric film. NASA subsequently licensed the electrode technology to Richard Charnitski, inventor of the VersaClimber, who founded HeartRate, Inc., to further develop and manufacture personal heart monitors and to produce exercise machines using the technology for the physical fitness, medical and home markets. Same technology is on both the Home and Institutional Model VersaClimbers. On the Home Model an infrared heart beat transmitter is worn under exercise clothing. Transmitted heartrate is used to control the work intensity on the VersaClimber using the heartrate as the speedometer of the exercise. This offers advantages to a full range of users from the cardiac rehab patient to the high level physical conditioning of elite athletes. The company manufactures and markets five models of the 1*2*3 HEARTRATE monitors that are used wherever people exercise to accurately monitor their heartrate. Company is developing a talking heartrate monitor that works with portable headset radios. A version of the heart beat transmitter will be available to the manufacturers of other aerobic exercise machines.
In the mid 70's, NASA saw a need for a long term electrocardiographic electrode suitable for use on astronauts. HeartRate Inc.'s insulated capacitive electrode is constructed of thin dielectric film applied to stainless steel surface, originally developed under a grant by Texas Technical University. HRI, Inc. was awarded NASA license and continued development of heartrate monitor for use on exercise machines for physical fitness and medical markets.
The aim of this study was to measure the heartrate (HR) response of eight elite water polo players during the four 7-min quarters of the game and to check for relationships with the physiological parameters of performance ([Formula: see text]O2max, Th1vent, Th2vent). Each athlete performed a [Formula: see text]O2max treadmill test and played a water polo game wearing a heartrate monitor. The game fatigue index was calculated as the ratio of the fourth-quarter HR to the first-quarter HR: HR4/HR1. The results showed a slight decrease in fourth-quarter HR compared with the first quarter, with the mean four-quarter HR equal to 79.9±4.2% of HRmax. Stepwise multiple regression analysis showed [Formula: see text]O2max to be the main explanatory factor of game intensity, i.e. game HR expressed in %HRreserve (R=0.88, P<0.01). We observed that higher aerobic capacity resulted in higher game intensity. We also observed a decrease in the playing intensity in the fourth quarter compared with the first, likely due to very high game involvement. We concluded that high aerobic capacity seems necessary to ensure high game intensity in water polo. This suggests that coaches should encourage their athletes to reach a minimum level of [Formula: see text]O2max and that HR monitoring could be of great interest in the control of water polo training sessions. PMID:24917687
Galy, O; Ben Zoubir, S; Hambli, M; Chaouachi, A; Hue, O; Chamari, K
ObjectiveTo investigate the effects of heartrate on the Doppler measurements of left ventricular function and to determine the normal pattern of rate dependency.SettingUniversity hospital specialising in internal medicine.Participants14 healthy male volunteers 10 of whom were studied.Intervention: Transoesophageal atrial pacing.Main outcome measuresAt paced rates of 70, 80, and 90 ppm the ratio of early to late peak transmitral flow velocity
T Oniki; Y Hashimoto; S Shimizu; T Kakuta; M Yajima; F Numano
The aim of the present study was to verify the validity of using exercise heartrate (HRex), HR recovery (HRR) and post-exercise HR variability (HRV) during and after a submaximal running test to predict changes in physical performance over an entire competitive season in highly trained young soccer players. Sixty-five complete data sets were analyzed comparing two consecutive testing sessions (3-4 months apart) collected on 46 players (age 15.1 ± 1.5 years). Physical performance tests included a 5-min run at 9 km h(-1) followed by a seated 5-min recovery period to measure HRex, HRR and HRV, a counter movement jump, acceleration and maximal sprinting speed obtained during a 40-m sprint with 10-m splits, repeated-sprint performance and an incremental running test to estimate maximal cardiorespiratory function (end test velocity V (Vam-Eval)). Possible changes in physical performance were examined for the players presenting a substantial change in HR measures over two consecutive testing sessions (greater than 3, 13 and 10% for HRex, HRR and HRV, respectively). A decrease in HRex or increase in HRV was associated with likely improvements in V (Vam-Eval); opposite changes led to unclear changes in V (Vam-Eval). Moderate relationships were also found between individual changes in HRR and sprint [r = 0.39, 90% CL (0.07;0.64)] and repeated-sprint performance [r = -0.38 (-0.05;-0.64)]. To conclude, while monitoring HRex and HRV was effective in tracking improvements in V (Vam-Eval), changes in HRR were moderately associated with changes in (repeated-)sprint performance. The present data also question the use of HRex and HRV as systematic markers of physical performance decrements in youth soccer players. PMID:21656232
Buchheit, M; Simpson, M B; Al Haddad, H; Bourdon, P C; Mendez-Villanueva, A
Triathlon, a sport that consists of swimming, biking and running, is growing in popularity throughout the country and the world. There is a large percentage of athletes that rely on the use of a heartrate monitor to gauge effort, but there is also a group of athletes that do not use this technology. The purpose of this research was
The aim of this study was to determine the changes in physical performance and resting heartrate variability (HRV) in professional futsal players during the pre-season and in-season training periods. 11 athletes took part in the study (age=24.3±2.9 years; height=176.3±5.2 cm; weight=76.1±6.3 kg), and performed a repeated-sprint ability (RSA) test [6×40 m (20+20 m with a 180° change of direction) sprints separated by 20 s of passive recovery] and Yo-Yo intermittent recovery test level 1 (Yo-Yo IR1) at 3 different moments (M1=beginning of pre-season; M2=end of pre-season; M3=mid in-season). The HRV indices were assessed at the same moments. After the short pre-season (3-week), mean RSA time (RSAmean) (M1=7.43±0.2 s; M2=7.24±0.2 s; P=0.003), decrement in RSA performance (RSAdecrement) (M1=6.7±0.3%; M2=5.0±0.9%; P=0.001), and Yo-Yo IR1 distance (M1=1.244±298 m; M2=1.491±396 m; P=0.002) were significantly improved (P<0.05). During the in-season (i. e., M3), performance in Yo-Yo IR1 and RSAmean were maintained. In contrast, RSAbest (M2=6.89±0.2 to M3=6.69±0.3; P=0.001) was improved and RSAdecrement (M2=5.0±0.9% to M3=6.6±0.9%; P=0.001) was impaired. At M2, there was an increase in HRV vagal-related indices compared with M1 that was maintained at M3. In conclusion, after a short pre-season, futsal players improved their RSA and Yo-Yo IR1 performance with concomitant improvements in HRV. These indices were maintained during the in-season period while RSAbest was improved and RSAdecrement impaired. Frequent monitoring of these performances and HRV indices may assist with identification of individual training adaptations and/or early signs of maladaption. PMID:23143705
Oliveira, R S; Leicht, A S; Bishop, D; Barbero-Álvarez, J C; Nakamura, F Y
Nocturnal white light exposure has shown marked results on subjective and objective indicators of alertness, vitality and mood, yet effects of white light during daytime and under usual office work conditions have not been investigated extensively. The current study employed a mixed-group design (N=32), testing effects of two illuminance levels (200lx or 1000lx at eye level, 4000K) during one hour of morning versus afternoon exposure. In four repeated blocks, subjective reports, objective performance and physiological arousal were measured. Results showed effects of illuminance on subjective alertness and vitality, sustained attention in tasks, and heartrate and heartrate variability. Participants felt less sleepy and more energetic in the high versus the low lighting condition, had shorter reaction times on the psychomotor vigilance task and increased physiological arousal. Effects of illuminance on the subjective measures, as well as those on heartrate were not dependent on time of day or duration of exposure. Performance effects were most pronounced in the morning sessions and towards the end of the one-hour exposure period. The effect on heartrate variability was also most pronounced at the end of the one-hour exposure. The results demonstrate that even under normal, i.e., neither sleep nor light deprived conditions, more intense light can improve feelings of alertness and vitality, as well as objective performance and physiological arousal. PMID:22564492
Smolders, K C H J; de Kort, Y A W; Cluitmans, P J M
OBJECTIVE Heartrate variability (HRV), a measure of autonomic function, has been associated with cognitive function, but studies are conflicting. Previous studies have also not controlled for familial and genetic influences. METHODS We performed power spectral analysis on 24-hour ambulatory ECGs in 416 middle-aged male twins from the Vietnam Era Twin Registry. Memory and learning were measured by verbal and visual selective reminding tests (SRT). Mixed-effect regression models were used to calculate associations between and within twin pairs, while adjusting for covariates. RESULTS The mean age (SD) was 55 (2.9) years. A statistically significant positive association was found between measures of HRV and verbal, but not visual, SRT scores. The most statistically significant unadjusted association was found between very low frequency (VLF) HRV and verbal total recall SRT, such that each logarithm of increase in VLF was associated with an increased verbal SRT score of 4.85 points (p=0.002). The association persisted despite adjustment for demographic and cardiovascular risk factors, and after accounting for familial, and genetic factors by comparing twins within pairs. A significant interaction was found between post-traumatic stress disorder (PTSD) and HRV, such that total power and ultra low frequency were associated with SRT in twins (n=362) without PTSD, but not in those with PTSD. CONCLUSION In conclusion, lower frequency spectra of HRV are associated with verbal, but not visual, learning and memory, particularly in subjects without PTSD. This association may indicate that autonomic nervous system dysregulation plays a role in cognitive decline. PMID:21715297
Shah, Amit J.; Su, Shaoyong; Veledar, Emir; Bremner, J. Douglas; Goldstein, Felicia C; Lampert, Rachel; Goldberg, Jack; Vaccarino, Viola
Objectives. This study sought to examine clinical determinants of heartrate variability and to report normative reference values for eight heartrate variability measures.Background. Although the clinical implications of heartrate variability have been described, clinical determinants and normative values of heartrate variability measures have not been studied systematically in a large community-based population.Methods. The first 2 h of
Hisako Tsuji; Ferdinand J. Venditti; Emily S. Manders; Jane C. Evans; Martin G. Larson; Charles L. Feldman; Daniel Levy
BACKGROUNDMeasurements of heartrate variability (HRV) are increasingly used as markers of cardiac autonomic activity.?AIMTo examine circadian variation in heartrate and HRV in children.?SUBJECTSA total of 57 healthy infants and children, aged 2 months to 15 years, underwent ambulatory 24 hour Holter recording. Monitoring was also performed on five teenagers with diabetes mellitus and subclinical vagal neuropathy in order to identify the origin of the circadian variation in HRV.?METHODSThe following variables were determined hourly: mean RR interval, four time domain (SDNN, SDNNi, rMSSD, and pNN50) and four frequency domain indices (very low, low and high frequency indices, low to high frequency ratio). A chronobiological analysis was made by cosinor method for each variable.?RESULTSA significant circadian variation in heartrate and HRV was present from late infancy or early childhood, characterised by a rise during sleep, except for the low to high frequency ratio that increased during daytime. The appearance of these circadian rhythms was associated with sleep maturation. Time of peak variability did not depend on age. Circadian variation was normal in patients with diabetes mellitus.?CONCLUSIONWe have identified a circadian rhythm of heartrate and HRV in infants and children. Our data confirm a progressive maturation of the autonomic nervous system and support the hypothesis that the organisation of sleep, associated with sympathetic withdrawal, is responsible for these rhythms.?? PMID:10906034
Massin, M.; Maeyns, K.; Withofs, N.; Ravet, F.; Gerard, P.; HEALY, M
Two strains of highly inbred mice were given classical conditioning with noise as CS and shock as US. Control groups for pseudoconditioning were included, and heartrate was measured before and after conditioning. Heartrate was elevated after conditioning (ppp=0.02). There was also a significant (p<0.01) main effect of strain on heartrate.
All About HeartRate (Pulse) Updated:Sep 30,2014 What should you know about your heartrate? Even if youre not an athlete, ... Where is it and what is a normal heartrate? The best places to find your pulse ...
Heartrate variability (HRV) is a reliable reflection of the many physiological factors modulating the normal rhythm of the\\u000a heart. In fact, they provide a powerful means of observing the interplay between the sympathetic and parasympathetic nervous\\u000a systems. It shows that the structure generating the signal is not only simply linear, but also involves nonlinear contributions.\\u000a Heartrate (HR) is
U. Rajendra Acharya; Paul K. Joseph; N. Kannathal; Choo Min Lim; Jasjit S. Suri
Many studies on the physiology of the cardiovascular system revealed that nonlinear chaotic dynamics govern the generation of the heartrate signal. This is also valid for the fetal heartrate (FHR) variability, where however the variability is affected by many more factors and is significantly more complicated than for the adult case. Recently an adaptive wavelet denoising method for
Students learn how to measure heartrate accurately. Then students design and carry out an experiment to test the effects of an activity or stimulus on heartrate, 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.
Heartrate variability (HRV), the beat-to-beat fluctuation of the heartrate, is a non-invasive test that measures the autonomic regulation of the heart. Assessment of HRV has been shown to predict the risk of mortality ...
Background Very few studies have analysed heartrate (HR) with regard to music playing, and the scarce evidence available is controversial. The purpose of this study was to analyse the HR response of professional musicians during their real-work activity. Methods Sixty-two voluntary professional musicians (20 women, 42 men), whose ages ranged between 15 and 71 years old, underwent the test while playing their instruments in real life scenarios, i.e. rehearsals, practice and public concerts. The musicians carried Sport Tester PE4000 (Polar®, Finland) pulsometers to record their HR. In order to compare data from differently aged subjects we calculated their Maximum Theoretical HeartRate (MTHR). Later on we found out the MTHR percentages (%MTHR) corresponding to the registered HR of each subject in different situations. The value of the MTHR for every musician was obtained by means of the 220 age (in years) formula. Results Throughout the HR recordings, we have observed that musicians present a heightened HR while playing (in soloists, mean and maximum HR were 72% and 85%MTHR, respectively). Cardiac demand is significantly higher in concerts than in rehearsals while performing the same musical piece. The HR curves corresponding to the same musician playing in repeated concerts (with the same programme) were similar. Conclusion The cardiac demand of a professional instrument player is higher than previously described, much greater than what would be expected from a supposedly sedentary activity. PMID:18655716
Iñesta, Claudia; Terrados, Nicolás; García, Daniel; Pérez, José A
We discuss periodicities in the heartrate in normal and transplanted hearts. We then consider the possibility of dimensional analysis of these periodicities in transplanted hearts and problems associated with the record.
The purpose of this project was to examine the effectiveness of a fitness infusion instructional strategy (FI) on children's activity levels and skill performance scores. This strategy included aerobic activity within the skill practice tasks and game play. In other words, students performed short bouts of activity between the practice and
The Push-Pull Effect (PPE) is a physiological phenomenon defined as a reduction of +Gz tolerance induced by a previous exposure to a -Gz acceleration, that may lead to loss of consciousness. Aim of this study was to evaluate, for the first time, the cardiac rhythm changes associated with PPE during real flights. Data were collected in 3 pilots during flights on the Aermacchi MB- 339-CD aircraft. In each flight, lasting about 60 minutes, ECG, respiration and 3D accelerations were recorded by a new smart garment (the MagIC System). The flight protocol included a maneuver eliciting a reference +5Gz acceleration for 15 seconds (Ref+5G), followed, after a while, by a push-pull maneuver with a profile characterized by a 5-s acceleration at -1Gz (PP-1G) and, with a 1G/s onset, by 15 seconds at +5Gz (PP+5G), so to induce the push-pull gravitational stress. From each ECG recording, a beat-by-beat RR Interval (RRI) series was derived. RRI mean, standard deviation (SDNN) and the RRI Root Mean Square of Successive Difference (RMSSD) were estimated in each pilot during the Ref+5G and the PP+5G maneuvers. As compared with Ref+5G, all pilots displayed significant reductions in RRI mean, SDNN and RMSSD during PP+5G. These findings are compatible with a PP-induced enhancement in the sympathetic drive to the heart -as shown by the reduction in RRI mean and SDNN- and a concomitant deactivation of the parasympathetic control as shown by the reduction in RMSSD. PMID:21097262
Di Rienzo, Marco; Castiglioni, Paolo; Meriggi, Paolo; Rizzo, Francesco; Trivelloni, Pierandrea; Cacopardo, Salvatore; Guadagno, Anton Giulio
The purpose of this project was to examine the effectiveness of a fitness infusion instructional strategy (FI) on childrens activity levels and skill performance scores. This strategy included aerobic activity within the skill practice tasks and game play. In other words, students performed short bouts of activity between the practice and game\\/application trials. Participants were 86 fifth?grade students who participated
Six well-trained firefighters performed six treadmill runs at 70% of the velocity at VO2max (Maximal aerobic velocity MAV = 13.26±0.3 km h). A recovery time of 1 week was allowed between trials. The first session was performed by subjects wearing only shorts (i.e. no fire jacket, J0). A similar protocol was applied subsequently to test the physiological eOEects associated with
Foued Ftaiti; Jean Claude Duflot; Caroline Nicol; Laurent GrÉlot
The major focus of the present proposal was to examine psychophysiological indices that show promise for invoking different modes of automation in an adaptive automation system. With the increased use of automation in today's work environment, people's roles in the work place are being redefined from that of active participant to one of passive monitor. Although the introduction of automated systems has a number of benefits, there are also a number of disadvantages regarding worker performance. Byrne and Parasuraman have argued for the use of psychophysiological measures in the development and the implementation of adaptive automation. While performance based, model based, and psychophysiologically based adaptive automation systems have been studied, the combined use of several psychophysiological measures has never been investigated. Such a combination provides the advantage of real time evaluation of the state of the subject in two relevant dimensions and offers a more realistic approach to the implementation of adaptive automation compared to the use of either dimension by itself.
The aim of the present study is to test the hypothesis that sprint swimming performance is enhanced by in-water passive recovery (IN) after sprint swimming bouts in well-trained adolescent swimmers. Using a randomized crossover study design, twelve well-trained adolescent swimmers performed two tests at the swimming pool after preliminary testing. They performed 5 bouts of 100m all-out swimming separated by 5 minutes of passive rest. Their individual in- or out-of-water passive recovery condition was randomized on the first day. In their second visit to the swimming pool the opposite recovery condition was indicated. More than 60% of the subjects which rested in-water were faster in the 5th bout when compared to the OUT group. However, no significant differences were found in blood lactate when IN and OUT were compared. After the first bout peak heartrate (HR peak) was lower in subsequent bouts for IN recovery when compared with OUT (p < 0.001). Thus, coaches and researchers should take into account that IN passive recovery may decrease loss of performance and diminish HR peak during sprint swimming bouts. This is particularly important given the use that many coaches give to HR as a tool in daily training. Key points In-water passive recovery minimizes the loss of performance during high intensity swimming Maximal HR is significantly reduced by in-water recovery Coaches should take this information into account when using HR to control swimming intensity Future research should study long-term effects induced by in-water passive recovery
Casuso, Rafael A.; Martínez-López, Emilio; Hita-Contreras, Fidel; Ruiz-Cazalilla, Irene; Cruz-Díaz, David; Martínez-Amat, Antonio
Heartrate variability (HRV) is significantly associated with average heartrate (HR), therefore, HRV actually provides information on two quantities, that is, on HR and its variability. It is difficult to conclude which of these two plays a principal role in the HRV clinical value, or in other words, what is the HR contribution to the clinical significance of HRV. Moreover, the association between HRV and HR is both a physiological phenomenon and a mathematical one. The physiological HRV dependence on HR is determined by the autonomic nervous system activity, but the mathematical one is caused by the nonlinear relationship between RR interval and HR. By employing modification methods of the HRV and HR relationship, it is possible to investigate the HR contribution to the HRV clinical value. Recent studies have shown that the removal of the HR impact on HRV makes HRV more predictive for noncardiac death, however, the enhancement of this impact causes HRV to be a better predictor of cardiovascular mortality. Thus, HR seems to constitute a cardiovascular factor of the HRV predictive ability. HR also influences the reproducibility of HRV, therefore, HR changes should be considered when one compares HRV measurements in a given patient. This review summarizes methodological aspects of investigations of the HRV and HR interaction as well as latest observations concerning its clinical utility. The issues discussed in this article should also refer to any other heartrate dynamics analysis which indices are significantly associated with HR. PMID:24602150
In this study respiratory rates of 3, 4, 6, 8, 10, 12, and 14 breaths per minute were employed to investigate the effects of these rates on heartrate variability (HRV). Data were collected 16 times at each respiratory rate on 3 female volunteers, and 12 times on 2 female volunteers. Although mean heartrates did not differ among these
Spontaneous variability of heart-rate has been related to three major physiological originating factors: quasi-oscillatory fluctuations thought to arise in blood-pressure control, variable frequency oscillations due to thermal regulation, and respiration; frequency selective analysis of cardiac interbeat interval sequences allows the separate contributions to be isolated. Using this method, a laboratory and field study of the effects of mental work load
Clarifies issues involved in use of heartrate as index of newborn attentional responsivity by reviewing related studies and concluding that heartrate variability can be used in studying attentional responsivity state, and intra-individual and individual variables. (ED)
1.A non-invasive, laser\\/fibre-optic, technique was developed to measure the heartrates of active unrestrained spiders. The heart-rates of 15 species were measured before, during and after activity.2.Maximum heart-rate varied between species. A possible association between maximum heartrate and prey-catching behaviour is proposed. Within a species, body-weight had no significant effect on maximum heart-rate. InArgyroneta, mature males had significantly higher maximum heart-rates
Proceeding from a formal definition of heartrate variability, some mathematical and statistical techniques from sampling statistics and time series analysis for the analytical evaluation of heartrate variability for ergonomics purposes are presented and compared. The concept of sampling statistics gives a measure of heartrate variability, arrived at by combining two measures, which were chosen according to a
Healthy human heartrate is known to fluctuate in a highly complex manner, displaying complexity characteristics such as those shared by physical systems at a critical state. It is, however, widely believed that chronic heart failure reduces this complexity and that heartrate data from chronic-heart-failure patients can be used for the validation of complexity measures and paradigms applicable both to heartrate and more generally to assess any system's complexity. Here, we counter the above belief, showing an increase in fluctuations and in complexity of heartrate in chronic-heart-failure patients, in particular those at risk of death. This is supported by evidence of increased non-Gaussianity and heteroscedasticity resulting from the emergence of a characteristic correlation scale in the magnitude correlation landscape.
Struzik, Z. R.; Kiyono, K.; Hayano, J.; Watanabe, E.; Yamamoto, Y.
HeartRate Variability Malvin Carl Teich Boston University and Columbia University http point processes Fractal-rate point processes S. B. Lowen and M. C. Teich, Fractal-Based Point Processes, Grasmere, UK, 2005 #12;CONGESTIVE HEART FAILURE INABILITY OF HEART TO INCREASE CARDIAC OUTPUT IN PROPORTION
The rate of heart beat is controlled by autonomic nervous system: accelerated by the sympathetic system and slowed by the parasympathetic system. Scaling properties in heartrate are usually related to the intrinsic dynamics of this physiological regulatory system. The two packages calculating local exponent spectra: Wavelet Transform Modulus Maxima and Multifractal Detrended Fluctuation Analysis (accessible from Physionet home page http://circ.ahajournals.org/cgi/content/full/101/23/e215) are tested, and then used to investigate the spectrum of singularity exponents in series of heartrates obtained from patients suffering from reduced left ventricle systolic function. It occurs that this state of a heart could be connected to some perturbation in the regulatory system, because the heartrate appears to be less controlled than in a healthy human heart. The multifractality in the heartrate signal is weakened: the spectrum is narrower and moved to higher values what indicate the higher activity of the sympatethic nervous system.
Makowiec, D.; Dudkowska, A.; Zwierz, M.; Galaska, R.; Rynkiewicz, A.
We examined performance, heartrate response and construct validity of the Yo-Yo IR2 test by testing 111 elite and 92 sub-elite soccer players from Norway and Denmark. VO2max, Yo-Yo IR1 and repeated sprint tests (RSA) (n = 51) and match-analyses (n = 39) were also performed. Yo-Yo IR2 and Yo-Yo IR1 performance was 41 and 25% better (P < 0.01) for elite than sub-elite players, respectively,
Jørgen Ingebrigtsen; Mads Bendiksen; Morten Bredsgaard Randers; Carlo Castagna; Peter Krustrup; Andreas Holtermann
This paper presents novel methods for classification of fetal heartrate (FHR) signals into categories that are meaningful for clinical implementation. They are based on generative models (GMs) and Bayesian theory. Instead of using scalar features that summarize information obtained from long-duration data, the models allow for explicit use of feature sequences derived from local patterns of FHR evolution. We compare our methods with a deterministic expert system for classification and with a support vector machine approach that relies on system-identification and heartrate variability features. We tested the classifiers on 83 retrospectively collected FHR records, with the gold-standard true diagnosis defined using umbilical cord pH values. We found that our methods consistently performed as well as or better than these, suggesting that the use of GMs and the Bayesian paradigm can bring significant improvement to automatic FHR classification approaches. PMID:24951678
We examined performance, heartrate response and construct validity of the Yo-Yo IR2 test by testing 111 elite and 92 sub-elite soccer players from Norway and Denmark. VO?max, Yo-Yo IR1 and repeated sprint tests (RSA) (n = 51) and match-analyses (n = 39) were also performed. Yo-Yo IR2 and Yo-Yo IR1 performance was 41 and 25% better (P < 0.01) for elite than sub-elite players, respectively, and heartrate after 2 and 4 min of the Yo-Yo IR2 test was 20 and 15 bpm (9 and 6% HRmax), respectively, lower (P < 0.01) for elite players. RSA performance and VO?max was not different between competitive levels (P > 0.05). For top-teams, Yo-Yo IR2 performance (28%) and sprinting distance (25%) during match were greater (P < 0.05) than for bottom-teams. For elite and sub-elite players, Yo-Yo IR2 performance was correlated (P < 0.05) with Yo-Yo IR1 performance (r = 0.74 and 0.76) and mean RSA time (r = -0.74 and -0.34). We conclude that the Yo-Yo IR2 test has a high discriminant and concurrent validity, as it discriminates between players of different within- and between-league competitive levels and is correlated to other frequently used intermittent elite soccer tests. PMID:22867048
Analysis of heartrate variability (HRV) provides a noninvasive index of autonomic nervous system activity. HRV has been shown to be reduced in heart failure. Preliminary data indicate that ? blockers improve clinical status in patients with heart failure, but HRV improvement remains to be demonstrated. Fifty-four patients from the randomized double-blind, placebo-controlled Cardiac Insufficiency Bisoprolol Study were included in
Francoise Pousset; Xavier Copie; Philippe Lechat; Patrice Jaillon; Jean-Pierre Boissel; Martin Hetzel; Frédéric Fillette; Willem Remme; Louis Guize; Jean-Yves Le Heuzey
Objective: A circuit of seven exercises was designed for a cardiac population. This study evaluated whether the patients achieved their training heartrate during the circuit, recommended to be 7085% of the maximum heartrate achieved during an exercise test. Design: Patients were randomly allocated to a starting exercise to balance any order effect from performing the exercises in a
Ten competitive ballroom dance couples performed simulated competitive sequences of Modern and Latin American dance. Heartrate was telemetered during the dance sequences and related to direct measures of oxygen uptake and heartrate obtained while walking on a treadmill. Linear regression was employed to estimate gross and net energy expenditures of the dance sequences. A multivariate analysis of variance
The acoustically based fetal heartrate monitor permits an expectant mother to perform the fetal Non-Stress Test in her home. The potential market would include the one million U.S. pregnancies per year requiring this type of prenatal surveillance. The monitor uses polyvinylidene fluoride (PVF2) piezoelectric polymer film for the acoustic sensors, which are mounted in a seven-element array on a cummerbund. Evaluation of the sensor ouput signals utilizes a digital signal processor, which performs a linear prediction routine in real time. Clinical tests reveal that the acoustically based monitor provides Non-Stress Test records which are comparable to those obtained with a commercial ultrasonic transducer.
Circuit requiring only four integrated circuits (IC's) measures both heartrate and breath rate. Phase-locked loops lock on heart-rate and respiration-rate input signals. Each loop IC contains two phase comparators. Positive-edge-triggered circuit used in making monitors insensitive to dutycycle variations.
Heartrate is not static but rather changes continuously in response to physical and mental demands. In fact, an invariant heartrate is associated with disease processes such as heart failure. Heartrate variability analysis is a noninvasive technique us...
Heart Physiology Lab Part 1: Pulse Rate Measure your pulse in each of the following conditions (in in the class. You may use Table 1 in the Heart Physiology Worksheet for this, if you wish. Once you have all the data, then do the following: 1. Calculate the average pulse rate in each condition by adding all
The relative stress of participation in wheelchair basketball, volleyball, tennis, and racquetball were determined by monitoring the heartrates of wheelchair athletes. Heartrates were recorded for 5 seconds every 30 seconds during monitoring sessions of 10 min or longer under game or practice conditions. Subjects were volunteer paraplegic athletes with lesions below T5 or with equivalent disability according to
Background: Both theoretical and clinical accounts of attention-deficit/hyperactivity disorder (ADHD) implicate a dysfunctional reinforcement system. This study investigated heartrate parameters in response to feedback associated with reward and response cost in ADHD children and controls aged 8 to 12. Methods: Heartrate responses (HRRs)
Luman, Marjolein; Oosterlaan, Jaap; Hyde, Christopher; van Meel, Catharina S.; Sergeant, Joseph A.
Background: Tai Chi is a famous training method in China, and jogging is a popular kind of exercise both in Austria and China. Nevertheless, there is little information concerning online monitoring of biosignals during both training activities in parallel. Within the last years innovative scientific monitoring tools for evaluating features of neurocardial fitness have been developed. Aims: The goal of this study was to demonstrate heartrate and heartrate variability analysis for the first time during Tai Chi and jogging. Volunteers and Methods: Continuous electrocardiographic monitoring over a period of 75 minutes was performed simultaneously in two healthy volunteers using the same type of equipment (medilog AR12 systems). Two healthy persons (both male, 49 years and 52 years, respectively), both hobby sportsmen, were monitored continuously during two resting periods before and after active sport and also during Tai Chi and jogging, respectively. Results: Data acquisition was performed without any technical problems in both subjects. Poincaré plots of sequential R-R intervals (beat to beat variability) show two ellipses of different shape and magnitude. During resting periods blood pressure effects can be clearly seen in one subject (jogging). The same effects, however reduced, are obvious in the other volunteer during Tai Chi. Conclusions: The present investigations during Tai Chi and jogging highlight the potential value of heartrate and heartrate variability monitoring even under difficult conditions. The innovative kind of analysis helps to show how well the human body reacts to sport, stress and recovery. PMID:22540068
Litscher, Gerhard; Zhang, Weibo; Huang, Tao; Wang, Lu
ORAL PRESENTATION ABSTRACT Design of an Arterial Blood Pressure, HeartRate Variability can be used to calculate the instantaneous heartrate and consequently the heartrate variability blood pressure, brachial artery, breathing rate, heartrate variability, photodiode
Presents a foundation for establishing measurable physical education outcomes, demonstrating how heartrate telemetry can help measure and achieve such outcomes. After explaining heartrate telemetry function, the article examines student and teacher outcomes that could be included in school physical education outcomes and achieved using heart
Heartrate variability (HRV) analysis has quantified the functioning of the autonomic regulation of the heart and heart's ability to respond. However, majority of studies on HRV report several differences between patients with congestive heart failure (CHF) and healthy subjects, such as time-domain, frequency domain and nonlinear HRV measures. In the paper, we mainly presented a new approach to detect congestive heart failure (CHF) based on combination support vector machine (SVM) and three nonstandard heartrate variability (HRV) measures (e.g. SUM_TD, SUM_FD and SUM_IE). The CHF classification model was presented by using SVM classifier with the combination SUM_TD and SUM_FD. In the analysis performed, we found that the CHF classification algorithm could obtain the best performance with the CHF classification accuracy, sensitivity and specificity of 100%, 100%, 100%, respectively. PMID:24747432
BACKGROUND--It has been shown that heartrate variability is decreased in patients with congestive heart failure and that depressed heartrate variability is associated with a propensity to ventricular arrhythmias. Little is known, however, about heartrate variability in patients with both congestive heart failure and ventricular arrhythmias. METHODS--Spectral heartrate variability was analysed from 24 hour ambulatory electrocardiograms in
L. Fei; P. J. Keeling; J. S. Gill; Y. Bashir; D. J. Statters; J. Poloniecki; W. J. McKenna; A. J. Camm
Soares-Caldeira, LF, de Souza, EA, de Freitas, VH, de Moraes, SMF, Leicht, AS, and Nakamura, FY. Effects of additional repeated sprint training during preseason on performance, heartrate variability, and stress symptoms in futsal players: A randomized controlled trial. J Strength Cond Res 28(10): 2815-2826, 2014-The aim of this study was to investigate whether supplementing regular preseason futsal training with weekly sessions of repeated sprints (RS) training would have positive effects on repeated sprint ability (RSA) and field test performance. Thirteen players from a professional futsal team (22.6 ± 6.7 years, 72.8 ± 8.7 kg, 173.2 ± 6.2 cm) were divided randomly into 2 groups (AddT: n = 6 and normal training group: n = 7). Both groups performed a RSA test, Yo-Yo intermittent recovery test level 1 (YoYo IR1), squat (SJ) and countermovement jumps (CMJ), body composition, and heartrate variability (HRV) measures at rest before and after 4 weeks of preseason training. Athletes weekly stress symptoms were recorded by psychometric responses using the Daily Analysis of Life Demands for Athletes questionnaire and subjective ratings of well-being scale, respectively. The daily training load (arbitrary units) was assessed using the session of rating perceived exertion method. After the preseason training, there were no significant changes for body composition, SJ, CMJ, and RSAbest. The YoYo IR1, RSAmean, RSAworst, and RSAdecreament were significantly improved for both groups (p ? 0.05). The HRV parameters improved significantly within both groups (p ? 0.05) except for high frequency (HF, absolute and normalized units, [n.u.]), low frequency (LF) (n.u.), and the LF/HF ratio. A moderate effect size for the AddT group was observed for resting heartrate and several HRV measures. Training load and psychometric responses were similar between both groups. Additional RS training resulted in slightly greater positive changes for vagal-related HRV with similar improvements in performance and training stress during the preseason training in futsal players. PMID:24662230
Soares-Caldeira, Lúcio F; de Souza, Eberton A; de Freitas, Victor H; de Moraes, Solange M F; Leicht, Anthony S; Nakamura, Fábio Y
Normal children achieve the same increase of oxygen uptake (VO2) in response to exercise even though resting and submaximal exercise heartrates vary greatly as a function of age, body size and physical conditioning. To determine whether the VO2 response to exercise is altered when heartrate is significantly reduced by heart disease, we compared 78 children who achieved a
Sinoatrial node is responsible for the origin of the wave of excitation, which spreads throughout the heart and orchestrates cardiac contraction via calcium-mediated excitation-contraction coupling. P wave represents the spread of excitation in the atria. It is well known that the autonomic nervous system controls the heartrate by dynamically altering both cellular ionic fluxes and the anatomical location of the leading pacemaker. In this study, we used isolated rabbit right atria and mathematical model of the pacemaker region of the rabbit heart. Application of isoproterenol resulted in dose-dependent acceleration of the heartrate and superior shift of the leading pacemaker. In the mathematical model, such behavior could be reproduced by a gradient of expression in ?1-adrenergic receptors along the superior-inferior axis. Application of acetylcholine resulted in preferentially inferior shift of pacemaker and slowing of the heartrate. The mathematical model reproduced this behavior with imposing a gradient of expression of acetylcholine-sensitive potassium channel. We conclude that anatomical shift of the leading pacemaker in the rabbit heart could be achieved through gradient of expression of ?1-adrenergic receptors and I(K,ACh). PMID:21937057
Lang, Di; Petrov, Valentin; Lou, Qing; Osipov, Grigory; Efimov, Igor R
Fetal heartrate variability has long been considered an indicator of fetal health, with a decrease in variability associated with the progression of disease. The purpose of this study was to develop an index of fetal health by applying the nonlinear analytic techniques of chaotic systems to measurements of the beat-to-beat intervals of the fetal heart. This study was carried
around new environments with caution. Sean did not receive any medication; however, he suffered from rectal prolapse problems and/or hemorrhoids. A dose of 80 mg of simethicone HeartRate and Problem Behavior 333 was given up to four...
Freeman, Rachel L.; Horner, Robert H.; Reichle, Joe
... range). Here are the steps for using the chart: Some medications may keep your heartrate from ... beats per minute (described above). Look at the chart. - Find your age. If your age falls between ...
This high-tech "teleacupuncture study" describes a neurovegetative ear acupressure effect in patients with chronic insomnia by using heartrate variability analysis. Heartrate (HR) and heartrate variability (HRV) measurements in 31 patients (mean age?±?SD: 54.3?±?10.6 years) were performed under standardized conditions in Harbin, China, and the data analysis was performed in Graz, Austria. Similar to our previous clinical and basic teleacupuncture research works, the electrocardiograms (ECGs) were recorded by an HRV Medilog AR12 system during ear acupressure of the Shenmen point on the left ear. HR decreased significantly (P < 0.05) during and after acupressure stimulation. The effect was not visible after the first stimulation, rather it appeared in the phase following the second acupressure stimulation (10 min after the first stimulation). Total HRV showed significant stimulation-dependent increases (P < 0.05), immediately after each acupressure stimulation with a maximum after the third stimulation (20 min after the first stimulation), but there was no long-lasting effect. The present results can serve as a solid basis for the further investigations of auricular point stimulation for noninvasive complementary use in treating insomnia. PMID:23476702
This high-tech teleacupuncture study describes a neurovegetative ear acupressure effect in patients with chronic insomnia by using heartrate variability analysis. Heartrate (HR) and heartrate variability (HRV) measurements in 31 patients (mean age?±?SD: 54.3?±?10.6 years) were performed under standardized conditions in Harbin, China, and the data analysis was performed in Graz, Austria. Similar to our previous clinical and basic teleacupuncture research works, the electrocardiograms (ECGs) were recorded by an HRV Medilog AR12 system during ear acupressure of the Shenmen point on the left ear. HR decreased significantly (P < 0.05) during and after acupressure stimulation. The effect was not visible after the first stimulation, rather it appeared in the phase following the second acupressure stimulation (10 min after the first stimulation). Total HRV showed significant stimulation-dependent increases (P < 0.05), immediately after each acupressure stimulation with a maximum after the third stimulation (20 min after the first stimulation), but there was no long-lasting effect. The present results can serve as a solid basis for the further investigations of auricular point stimulation for noninvasive complementary use in treating insomnia. PMID:23476702
Objective: This study was designed to quantify and compare the instantaneous heartrate dynamics and cardiopulmonary interactions during sequential performance of three meditation protocols with different breathing patterns. Background: We analyzed beat-to-beat heartrate and continuous breathing signals from 10 experienced meditators (4 females; 6 males; mean age 42 years; range 2955 years) during three traditional interventions: relaxation response, breath
C.-K. Peng; Isaac C. Henry; Joseph E. Mietus; Jeffrey M. Hausdorff; Gurucharan Khalsa; Herbert Benson; Ary L. Goldberger
Vaz, MS, Picanço, LM, and Del Vecchio, FB. Effects of different training amplitudes on heartrate and heartrate variability in young rowers. J Strength Cond Res 28(10): 2967-2972, 2014-The aim of this study was to investigate the autonomic nervous system recovery and the psychological response as a result of 3 training amplitudes on heartrate (HR), heartrate variability (HRV), and rate of perceived exertion (RPE) in rowing. Eight young rowers (16.8 ± 1.4 years) performed, in a randomized fashion, 2 sessions of high-intensity interval training, with high and low amplitude and a continuous training (CT) session, with the same exercise duration (10 minutes) and mean intensity (60% of maximal stroke test). The data of HR, HRV, and RPE were collected 5 minutes before, immediately after each session, and 24 hours later. High amplitude promoted higher impact in maximum HR (p ? 0.05) and RPE (p < 0.001) when compared with CT. For the time domain HRV variable, there was a statistically significant difference between moments of rest (pretraining or post 24 hours) and posttraining in all training sessions. Originally, we conclude that training with higher load variation between effort and recovery impacts HRV, HR, and RPE with greater intensity, but the younger rowers were ready for new training sessions 24 hours after either training method. Coaches can use the polarized training method, observing the stimulus nature and time required for recovery, because it may be an adequate strategy for the development of rower's conditioning. PMID:24736775
Vaz, Marcelo S; Picanço, Luan M; Del Vecchio, Fabrício B
The rate of ventilation and route of breathing (i.e., nasal versus oronasal) are potential determinants of pollutant doses to target sites in the lung. However, the lack of accurate methods for ambulatory measurement of ventilation has hindered estimation of exposure and dose in freely ranging individuals, complicating the interpretation of the relationships among exposure, dose, and response in epidemiological studies. The goal of this project was to develop and validate a method of monitoring ventilation for large-scale epidemiologic investigations. We estimated ventilation for individual subjects from ambulatory heartrate monitoring, using the relationship between ventilation and heartrate that had been obtained during exercise testing. Fifty-eight subjects participated in the study, which included healthy adults and children, and subjects with lung and heart disease. Subjects performed cycle exercise and tasks involving lifting and vacuuming. Work loads of progressive and variable order were used in the testing. Conventional methods were used to measure heartrate and total ventilation, and a sampling mask was developed to measure the partitioning of breathing between oral and nasal routes. The minute ventilation-heartrate relation was evaluated under steady-state and varying work loads. In a second phase, subjects wore wristwatch monitors that recorded their heartrates, minute by minute, throughout the day. Subjects recorded activities, locations, and levels of exertion. Two 16-hour monitoring periods were obtained from each subject. The laboratory findings documented considerable intersubject variability in the minute ventilation-heartrate relation with a two- to five-fold range in the coefficients describing the change in ventilation relative to heartrate. This variation implies that individual testing is required to derive accurate predictive equations. Minute ventilation-heartrate regressions for the maximal progressive exercise test and for the test with a nonprogressive submaximal work load sequence were comparable, indicating that varying the sequence of work loads does not substantially affect the minute ventilation-to-heartrate ratio. During upper body work (e.g., lifting), the minute ventilation-to-heartrate ratio was one-third greater than during lower body exercise. Diverse patterns of partitioning breathing between oral and nasal routes were observed with increasing oral ventilation in most subjects as work load increased. In the field, heartrate and activity patterns were monitored successfully in adults and children with low rates of instrument failure and noncompliance.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:8216970
Samet, J M; Lambert, W E; James, D S; Mermier, C M; Chick, T W
Aim was to elucidate autonomic responses to dynamic and static (isometric) exercise of the lower limbs eliciting the same moderate heartrate (HR) response. Method: 23 males performed two kinds of voluntary exercise in a supine position at similar heartrates: static exercise (SE) of the lower limbs (static leg press) and dynamic exercise (DE) of the lower limbs (cycling). Subjective effort, systolic (SBP) and diastolic blood pressure (DBP), mean arterial pressure (MAP), rate pressure product (RPP) and the time between consecutive heart beats (RR-intervals) were measured. Time-domain (SDNN, RMSSD), frequency-domain (power in the low and high frequency band (LFP, HFP)) and geometric measures (SD1, SD2) as well as non-linear measures of regularity (approximate entropy (ApEn), sample entropy (SampEn) and correlation dimension D2) were calculated. Results: Although HR was similar during both exercise conditions (88±10 bpm), subjective effort, SBP, DBP, MAP and RPP were significantly enhanced during SE. HRV indicators representing overall variability (SDNN, SD 2) and vagal modulated variability (RMSSD, HFP, SD 1) were increased. LFP, thought to be modulated by both autonomic branches, tended to be higher during SE. ApEn and SampEn were decreased whereas D2 was enhanced during SE. It can be concluded that autonomic control processes during SE and DE were qualitatively different despite similar heartrate levels. The differences were reflected by blood pressure and HRV indices. HRV-measures indicated a stronger vagal cardiac activity during SE, while blood pressure response indicated a stronger sympathetic efferent activity to the vessels. The elevated vagal cardiac activity during SE might be a response mechanism, compensating a possible co-activation of sympathetic cardiac efferents, as HR and LF/HF was similar and LFP tended to be higher. However, this conclusion must be drawn cautiously as there is no HRV-marker reflecting pure sympathetic cardiac activity. PMID:24349546
Recent health research has focused on subtle energy and vibrational frequency as key components of health and healing. In particular, intentional direction of bioenergy is receiving increasing scientific attention. This study investigates the effect of the healer's electromagnetic (EM) heart field upon subjects during energy healing as measured by synchronization of heartrates and scores on a Subjective Units of Distress (SUD) scale and a Profile of Mood States (POMS) inventory. A nonequivalent pretest-posttest design was used based on heartrate comparisons between healer and subject and correlated with pre-and posttest SUD and POMS scores. Subjects included those who sat within the 3- to 4-foot "strong" range of the independent variable, the healer's heart field, while performing self-application of WHEE (the wholistic hybrid derived from EMDR [eye movement desensitization and reprocessing], and EFT [emotional freedom technique]), a meridian-based tapping technique (n=50); and those who performed the same process beyond the 15- to 18-foot range of the healer's EM heart field (n=41). The dependent variables were heartrate, SUD, and POMS inventory. All subjects completed these measures within 1 hour. Study results showed statistically significant heart-rate synchronization with the intervention population. In addition, SUD and POMS scores demonstrated considerably more improvement than in the control population, indicating additional benefit beyond the meridian-based therapies, such as WHEE, alone. Additional findings and future research recommendations are presented in this article. PMID:20664147
The objective is to identify whether it is possible to discriminate between normal and abnormal physiological state based on heartrate (HR), heartrate variability (HRV) and movement activity information in subjects with cardiovascular complications. HR, HRV and movement information were obtained from cardiac patients over a period of 6 weeks using an ambulatory activity and single lead ECG monitor.
Although there has been some discussion regarding the appropriate length of time necessary for subjects to reach true resting heartrate prior to experimentation, the relevance of conclusions from that discussion for multiple baseline studies of heartrate has not been demonstrated. To investigate this issue, data were collected from 39 males and 33 females following a standard 15-minute adaptation
Trace conditioning was evaluated in newborn infants by measurements of heartrate responses to a conditioned stimulus in anticipation of or in absence of the unconditioned stimulus. Data suggest females have higher levels of heartrate variability than males, which parallels their greater conditionability. (GO)
Studies of heartrate variability in people who faint may yield insights into normal physiologic mechanisms which probably are dynamic. These insights might be gained because fainting appears to be due to a breakdown of these mechanisms. Tilt table testing reliably induces fainting in patients with a history of fainting and can be used to study these mechanisms. During tilt tests ending in fainting heartrate changes markedly, with a loss of high-frequency components on power spectral analysis and a progressive slowing of overall sinus node discharge. These changes appear to be due to changes in efferent vagal nerve traffic. Several possible mechanisms of these changes in heartrate variability are discussed.
Background:?Test anxiety can be potentially serious when it leads to high levels of distress and poor academic performance in students. While research suggests that a small degree of anxiety can act as a motivator, debilitating test anxiety can disrupt mental processes, especially when the task is demanding, as is the case in formal academic assessment. As such, test anxiety is
MULTIRESOLUTION WAVELET ANALYSIS OF HEARTRATE VARIABILITY FOR HEART-FAILURE AND HEART- viation OW,V(m) is found to be superior to two commonly used heart-rate-variability me~ures for diagnosing a study on a collection of elec- - irocardiograms from patients who suffer from conges- tive heart failure
athletes from training status, different types of exercise training, sex and ageing, presented from both cross-sectional and longitudinal studies. The predictability of HRV in over-training, athletic condition and athletic performance is also included. Finally, some recommendations concerning the application of HRV methods in athletes are made. The cardiovascular system is mostly controlled by autonomic regulation through the activity of sympathetic
This paper presents a current invention for monitoring the athletes' heartrate during training or exercise session. A bracelet with different color code of Light Emitting Diode (LED) is designed as a wrist heartrate monitor. This color-coding makes the heartrate easier to monitor and enabling the user to know their heartrate range at a certain moment. Our
N. H. Mahmood; N. Uyop; N. Zulkarnain; F. K. Che Harun; M. F. Kamarudin; A. Linoby
It was reported that the measurement error of the fetal heartrate variability (FHRV), which was obtained by a ultrasound heartrate monitor with the Doppler signal, was large even if the auto-correlation technique was used. Nevertheless, fetal heartrate monitoring by the ultrasound heartrate monitor is necessary to determine the status of the fetus because an invasive test
Y. Noguchi; H. Mamune; S. Sugimoto; J. Yoshida; H. Sasa; H. Kobayashi; M. Kobayashi
Studies on the physiology of the cardiovascular system suggested that the generation of the heartrate signal is governed by nonlinear chaotic dynamics. No study investigated the nonlinear dynamics of heartrate in hyperthyroidism. We examined whether the heartrate dynamics of hyperthyroid patients is different from normal controls by the nonlinear analysis of heartrate variability (HRV) with correlation
ORIGINAL ARTICLE Instantaneous changes in heartrate regulation due to mental load in simulated bands (LF 0.04Â0.15 Hz; HF 0.15Â0.4 Hz), in addition to the traditional linear heartrate variability) performed twice, each followed by a rest condition. The heartrate and measures related to vagal modulation
Learning about the relationship between heartrate and physical activity is an important aspect of fitness education. Use of a heartrate monitor (HRM) helps a student to understand how stretching and large muscle movements gradually increase the heartrate and blood flow, and enables students to measure their exercise heartrates and set goals
The heartrate is a basic health indicator, useful in both clinical measurements and home health care. Current home care systems often require the attachment of electrodes or other sensors to the body, which can be cumbersome to the patient. Moreover, some measurements are sensitive to movement artifacts, are not user-friendly and require a specialized supervision. In this paper, a
Low heartrate (HR) variability is a risk factor for cardiac mortality in various patient populations, but it has not been well established whether patients with long-standing hypertension have abnormalities in the autonomic modulation of HR. Time and frequency domain measures of HR variability were compared in randomly selected, age-matched populations of 188 normotensive and 168 hypertensive males (mean age
Heikki V. Huikuri; Antti Ylitalo; Sirkku M. Pikkujämsä; Markku J. Ikäheimo; K. E. Juhani Airaksinen; Asko O. Rantala; Mauno Lilja; Y. Antero Kesäniemi
Because of the special structures of intraaorta pump, the pressure and blood flow sensors cannot be implanted in the blood pump. Moreover, the cardiovascular pump is a very complex system that has no accurate model but much uncertainty and disturbance. Hence, the conventional control algorithm cannot achieve good performance. To overcome this problem, on one hand, a cardiovascular pump model is established. The heartrate in this model is chosen as a controlled variable that is a nonlinear function of the mean arterial pressure. On the other hand, a fuzzy logic feedback control algorithm, which maintains the actual heartrate tracking the desired heartrate, is designed. Computer simulations are performed to verify the robustness and dynamic characters of the controller. The simulation results demonstrate that the controller can maintain the actual heartrate tracking the desired one without static error. When the desired heartrate changed from 100 to 80 bpm, the settling time is <10 seconds. When the peripheral resistance increases from 1.0 to 0.7 mm Hg/ml, the settling time is <10 seconds. PMID:21307771
Eur Heart J . Author manuscript Page /1 11 Chronic heartrate reduction with ivabradine improves the adaptations of left ventricular function and calcium handling to chronic heartrate reduction with ivabradine). Ivabradine reduced heartrate by about 20 and improved both ejection fraction (% + 35 ) and systolic
Analysis of HeartRate Variability Using Time-Varying Filtering of Heart Transplanted Patients the heartrate variability (HRV), obtained by using the time-varying integral pulse frequency modulation of the filtered modulation of the heartrate due to respiration is compared to the date of transplantation taking
We studied the influence of long term therapy, in essential hypertensives, with the CCB amlodipine, on sympathetic and parasympathetic activity, by analyzing heartrate and heartrate variability. 28 patients (16 male, 12 female, mean age 60+9,7yrs) with essential hypertension (stage 1 or 2 according the sixth report of the JNC) received daily 5mg amlodipine as monotherapy. In those remaining
Heartrate variability (HRV), the beat-to-beat variation in either heartrate or the duration of the RR interval the heart period, has become a popular clinical and investigational tool. The temporal fluctuations in heartrate exhibit a marked synchrony with respiration (increasing during inspiration and decreasing during expiration the so called respiratory sinus arrhythmia, RSA) and are widely believed to reflect changes in cardiac autonomic regulation. Although the exact contributions of the parasympathetic and the sympathetic divisions of the autonomic nervous system to this variability are controversial and remain the subject of active investigation and debate, a number of time and frequency domain techniques have been developed to provide insight into cardiac autonomic regulation in both health and disease. It is the purpose of this essay to provide an historical overview of the evolution in the concept of HRV. Briefly, pulse rate was first measured by ancient Greek physicians and scientists. However, it was not until the invention of the Physicians Pulse Watch (a watch with a second hand that could be stopped) in 1707 that changes in pulse rate could be accurately assessed. The Rev. Stephen Hales (1733) was the first to note that pulse varied with respiration and in 1847 Carl Ludwig was the first to record RSA. With the measurement of the ECG (1895) and advent of digital signal processing techniques in the 1960s, investigation of HRV and its relationship to health and disease has exploded. This essay will conclude with a brief description of time domain, frequency domain, and non-linear dynamic analysis techniques (and their limitations) that are commonly used to measure HRV. PMID:22144961
A micropower detector chip integrated with CMOS technology has been developed for a hand-held heartrate monitoring instrument mainly used by professional athletes and others who exercise seriously to increase their endurance and overall performance. The chip uses linear bandpass filtering and threshold detection and is implemented with analog switched-capacitor (SC) and digital techniques. The bandpass filter transfer function is
Antti Ruha; Juha Kostamovaara; Seppo Säynäjäkangas
We consider the question of how the cardiac rhythm spontaneously self-regulates and propose a new mechanism as a possible answer. We model the neuroautonomic regulation of the heartrate as a stochastic feedback system and find that the model successfully accounts for key characteristics of cardiac variability, including the 1/f power spectrum, the functional form and scaling of the distribution of variations of the interbeat intervals, and the correlations in the Fourier phases which indicate nonlinear dynamics.
Fetal heartrate (FHR) monitoring, before and during labor, is a very\\u000aimportant medical practice in the detection of fetuses in danger. We clustered\\u000aFHR tracings by compression in order to identify abnormal ones. We use a\\u000arecently introduced approach based on algorithmic information theory, a\\u000atheoretical, rigorous and well-studied notion of information content in\\u000aindividual objects. The new method
OBJECTIVESWe sought to determine a generalized equation for predicting maximal heartrate (HRmax) in healthy adults.BACKGROUNDThe age-predicted HRmax equation (i.e., 220 ? age) is commonly used as a basis for prescribing exercise programs, as a criterion for achieving maximal exertion and as a clinical guide during diagnostic exercise testing. Despite its importance and widespread use, the validity of the HRmax
In the modern industrialized countries every year several hundred thousands of people diedue to the sudden cardiac death. The individual risk for this sudden cardiac death cannot bedefined precisely by common available, non-invasive diagnostic tools like Holter-monitoring,highly amplified ECG and traditional linear analysis of heartrate variability (HRV). Therefore,we apply some rather unconventional methods of nonlinear dynamics to analyse the
J. Kurths; A. Voss; P. Saparin; A. Witt; H. J. Kleiner; N. Wessel
The present study was concerned with certain individual differences that relate to a subjects ability to increase his heartrate on command when given appropriate external feedback. The main purpose was to extend to the operant conditioning paradigm Eysencks theory that introverts classically condition more readily than extraverts. A second purpose was to determine which personality factorsextraversion, anxiety, and ability
The long-term aims of this study are to find a parameter derived from the ECG that has a high sensitivity and specificity to asphyxia and, once we know or suspect that asphyxia occurred, to estimate how severe it was. We carried out a pilot study in which 24 adult Wistar rats were anaesthetised and subjected to controlled asphyxia for specified durations. We measured the pH, 'neurological score' and the ECG, extracting from this heartrate and heartrate variability (HRV). We have developed a technique capable of detecting asphyxia in less than 1 min, based on monitoring the ECG and estimating HRV by measuring the standard deviation of normal RR intervals (the RR interval is the time interval between two consecutive R-points of the QRS complex). In all cases the heartrate decreased and HRV increased, by an average of 46 +/- 33 ms in relation to the baseline, at the onset of asphyxia. The comparison of the base level of HRV after and before asphyxia shows promise for the estimation of the severity of the episode; however, the limitations of this study should be noted as they include the small size of the cohort and the methods of analysis. PMID:12507311
Boardman, A; Schlindwein, F S; Thakor, N V; Kimura, T; Geocadin, R G
Using a phase plane analysis (PPA) of the spatial spread of trajectories of the fetal heartrate and its time-derivative we characterize the fetal heartrate patterns (fHRP) as defined by Nijhuis. For this purpose, we collect 22 fetal magnetocardiogram using a 151 SQUID system from 22 low-risk fetuses in gestational ages ranging from 30 to 37 weeks. Each study lasted for 30 minutes. After the attenuation of the maternal cardiac signals, we identify the R waves using an adaptive Hilbert transform approach and calculate the fetal heartrate. On these datasets, we apply the proposed approach and the traditionally used approaches such as standard deviation of the normal to normal intervals (SDNN) and root mean square of the successive difference (RMSSD). Heartrate patterns are scored by an expert using Nijhuis criteria and revealed A, B, and D patterns. A receiver operator characteristic (ROC) curve is used to assess the performance of the metric to differentiate the different patterns. Results showed that only PPA was able to differentiate all pairs of fHRP with high performance. PMID:22254593
Vairavan, Srinivasan; Sriram, Bhargavi; Wilson, James D.; Preissl, Hubert; Eswaran, Hari
1 Adaptive Multiscale Complexity Analysis of Fetal HeartRate H. Helgason(1), P. Abry(2), P. Gonc morbidity and mortality. Fetal heartrate monitoring plays an important role in early detection of acidosis of fetal heartrate data, based on producing a collection of piecewise linear approximations of varying
ORIGINAL PAPER Modeling HeartRate Regulation--Part II: Parameter Identification and Analysis K. R of this study we introduced a 17- parameter model that can predict heartrate regulation during postural change to adequately represent the observed heartrate response. In part I and in previous work (Olufsen et al. 2006
Development of HeartRate Circadian Rhythm in Chickens K. Moriyaa *, R. Akiyamab , E.M. Dzialowskic, University of North Texas, Denton, Texas, USA ABSTRACT In chick embryos, various instantaneous heartrate of mean heartrate (MHR) have been elucidated. IHR changes have also measured in newly hatched and young
ORIGINAL PAPER Simultaneous biologging of heartrate and acceleration, and their relationships, implanted data loggers were used to simultaneously measure heartrate (fH), visceral temperature sample. Heartrate alone and in combination with acceleration, rather than acceleration alone, provided
Determined the heartrate of 5 male squirrel monkeys by FM telemetry during the formation of status orders assessed with a full pair comparison design on 6 occasions over a 3-wk period. Heartrate was related to rank on the status order by a curvilinear function with the middle-ranking Ss showing the lowest heartrate during test sessions, but not
Daily long-term monitoring of heartrates is important for health management. An analysis of heartrate variability can facilitate the early discovery of illnesses. In this study, we paid attention to the method of measuring resting heartrate over long term. An acceleration sensor was set inside the down kilt as it opposing to subject's left chest. Mechanical vibration from
A considerable body of evidence indicates that elevated resting heartrate is an independent, modifiable risk factor for cardiovascular events and mortality in patients with coronary artery disease. Elevated heartrate can produce adverse effects in several ways. Firstly, myocardial oxygen consumption is increased at high heartrates, but the time available for myocardial perfusion is reduced, increasing the likelihood
Motor activity and tonic heartrate were monitored in 62 drug-free panic disorder patients and 40 normal control subjects. Mean daily activity, mean waking heartrate controlled for activity, and mean sleeping heartrate were determined. Panic disorder patients without phobic avoidance showed higher activity than control subjects or patients with limited or extensive avoidance. Similarly, an \\
Duncan B. Clark; C. Barr Taylor; Chris Hayward; Roy King; Jürgen Margraf; Anke Ehlers; Walton T. Roth; W. Stewart Agras
Heartrate slows immediately after smoking cessation but it is unclear whether this is a permanent or transient effect. Examining this issue may improve our understanding of nicotine withdrawal effects. A transient heartrate pattern would suggest that the cardiovascular system adapts chronically to nicotine and requires a period of adjustment to achieve a new homeostasis after cessation. Heartrate
The study investigated the effects of expectancy on the reduction of cold pressor test pain using heartrate biofeedback training. Thirty-six male subjects were given an initial 45-sec cold pressor test, 25 heartrate decrease feedback training trials, and a final cold pressor test in which they were told to decrease their heartrate, but without the aid of feedback.
HEARTRATE VARIABILITY AS DETERMINISM WITH JUMP STOCHASTIC PARAMETERS JIONGXUAN ZHENG, JOE SKUFCA of the system. Key words. heartrate variability, electrocardiography, next angle map, circle map, jump process, consistent with our expectation that heartrate variability should vary continuously . We find the resultant
Heartrate variability is a result of the superimposition of different sources of variation which are systemized. Three parameters are used to describe the phenomenon of heartrate variation. The range of variation of these parameters is discussed using examples from both laboratory and field investigations. Analyses demonstrate a correlation between heartrate and their variability. Discussion of of the
RESEARCH PAPER Complexity of heartrate variability predicts outcome in intensive care unit- 2014-308389 ABSTRACT Background Heartrate variability (HRV) has been proposed as a predictor of acute the autonomic nervous system and induces cardiovascular responses.1ï¿½3 Heartrate variability (HRV) has been
Heartrate 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 heartrate 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.
Shaffer, Fred; McCraty, Rollin; Zerr, Christopher L.
Quantification of cardiac autonomic activity and control via heartrate (HR) and heartrate variability (HRV) is known to provide prognostic information in clinical populations. Issues with regard to standardization and interpretation of HRV data make the use of the more easily accessible HR on its own as an indicator of autonomic cardiac control very appealing. The aim of this study was to investigate the strength of associations between an important cardio vascular health metric such as VO2max and the following: HR, HRV indicators, and HR normalized HRV indicators. A cross sectional descriptive study was done including 145 healthy volunteers aged between 18 and 22 years. HRV was quantified by time domain, frequency domain and Poincaré plot analysis. Indirect VO2max was determined using the Multistage Coopers test. The Pearson correlation coefficient was calculated to quantify the strength of the associations. Both simple linear and multiple stepwise regressions were performed to be able to discriminate between the role of the individual indicators as well as their combined association with VO2max. Only HR, RR interval, and pNN50 showed significant (p < 0.01, p < 0.01, and p = 0.03) correlations with VO2max. Stepwise multiple regression indicated that, when combining all HRV indicators the most important predictor of cardio vascular fitness as represented by VO2max, is HR. HR explains 17% of the variation, while the inclusion of HF (high frequency HRV indicator) added only an additional 3.1% to the coefficient of determination. Results also showed when testing the normalized indicators, HR explained of the largest percentage of the changes in VO2max (16.5%). Thus, HR on its own is the most important predictor of changes in an important cardiac health metric such as VO2max. These results may indicate that during investigation of exercise ability (VO2max) phenomena, quantification of HRV may not add significant value. PMID:24312058
Grant, Catharina C.; Murray, Carien; Janse van Rensburg, Dina C.; Fletcher, Lizelle
Quantification of cardiac autonomic activity and control via heartrate (HR) and heartrate variability (HRV) is known to provide prognostic information in clinical populations. Issues with regard to standardization and interpretation of HRV data make the use of the more easily accessible HR on its own as an indicator of autonomic cardiac control very appealing. The aim of this study was to investigate the strength of associations between an important cardio vascular health metric such as VO2max and the following: HR, HRV indicators, and HR normalized HRV indicators. A cross sectional descriptive study was done including 145 healthy volunteers aged between 18 and 22 years. HRV was quantified by time domain, frequency domain and Poincaré plot analysis. Indirect VO2max was determined using the Multistage Coopers test. The Pearson correlation coefficient was calculated to quantify the strength of the associations. Both simple linear and multiple stepwise regressions were performed to be able to discriminate between the role of the individual indicators as well as their combined association with VO2max. Only HR, RR interval, and pNN50 showed significant (p < 0.01, p < 0.01, and p = 0.03) correlations with VO2max. Stepwise multiple regression indicated that, when combining all HRV indicators the most important predictor of cardio vascular fitness as represented by VO2max, is HR. HR explains 17% of the variation, while the inclusion of HF (high frequency HRV indicator) added only an additional 3.1% to the coefficient of determination. Results also showed when testing the normalized indicators, HR explained of the largest percentage of the changes in VO2max (16.5%). Thus, HR on its own is the most important predictor of changes in an important cardiac health metric such as VO2max. These results may indicate that during investigation of exercise ability (VO2max) phenomena, quantification of HRV may not add significant value. PMID:24312058
Grant, Catharina C; Murray, Carien; Janse van Rensburg, Dina C; Fletcher, Lizelle
This article, created by Allen L. Shoemaker of Calvin College, describes a dataset on body temperature, gender, and heartrate. 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.
Severe brain damage may cause alterations of cardiovascular function: heartrate, particularly, require the integrity of the\\u000a vagal, sympathetic and central nervous systems. We studied brain-heart functional relation and neurovegetative modulation\\u000a by spectral analysis of heartrate variability (HRV). This technique allows separate evaluation of the sympathetic and vagal\\u000a components of heartrate modulation.\\u000a \\u000a In order to correlate changes in
Luigi G. Lacquaniti; Marco Irone; Stefano Barbacini; Fulgido Merlo; Paolo Demo; Carlo Pellegrin; Maurizio Dan
. Heartrate variability is a noninvasive index of the neural activity of the heart. The present study examined heartrate\\u000a variability indices in 210 infants and children aged 3 days to 14 years to obtain normal ranges for all age classes. Heart\\u000a rate variability was measured by calculating mean RR interval over the length of the analysis, mean RR
Autonomic nervous system (ANS) dysfunction has been suggested in patients with chronic fatigue syndrome (CFS). In this study, we sought to determine whether increased heartrate (HR) and reduced heartrate variability (HRV) parameters observed in CFS patients during wakefulness persist during sleep. To this end, we compared heartrate (HR) and HRV as indicators of ANS function in CFS
Roumiana S. Boneva; Michael J. Decker; Elizabeth M. Maloney; Jin-Mann Lin; James F. Jones; Helgi G. Helgason; Christine M. Heim; David B. Rye; William C. Reeves
We compared heartrate variability measures of 11 normal children (412 years) to 23 normal adults (2143 years) to study the effect of age on heartrate variability measures. Children had a significantly higher supine and standing heartrate and lower supine and standing systolic diastolic blood pressure. Children also had a significantly higher supine standard deviation of HR, supine
V. K. Yeragani; R. Pohl; R. Berger; R. Balon; K. Srinivasan
Objective There is limited research available regarding a possible relationship between resting heartrate variability (HRV) and post-exercise\\u000a heartrate recovery (HRR). The aim of this study was to examine the relationship between resting HRV and HRR after maximal\\u000a exercise.\\u000a \\u000a \\u000a \\u000a Methods Sixty-six college age men participated in this study. HRV was measured in a supine position before and for 30 min after a
Michael R. Esco; Michele S. Olson; Henry N. Williford; Daniel L. Blessing; David Shannon; Peter Grandjean
Background Spaceflight causes changes in the cardiovascular control system. The aim of this study was to evaluate postflight recovery of linear and nonlinear neural markers of heartrate modulation, with a special focus on day-night variations. Material/Methods Twenty-four-hour Holter ECG recordings were obtained in 8 astronauts participating in space missions aboard the International Space Station (ISS). Data recording was performed 1 month before launch, and 5 and 30 days after return to Earth from short- and long-term flights. Cardiovascular control was inferred from linear and nonlinear heartrate variability (HRV) parameters, separately during 2-hour day and 2-hour night recordings. Results No remarkable differences were found in the postflight recovery between astronauts from short- and long-duration spaceflights. Five days after return to Earth, vagal modulation was significantly decreased compared to the preflight condition (day: p=0.001; night: p=0.019), while the sympathovagal balance was strongly increased, but only at night (p=0.017). A few nonlinear parameters were reduced early postflight compared to preflight values, but these were not always statistically significant. No significant differences remained after 30 days of postflight recovery. Conclusions Our results show that 5 days after return from both short- and long-duration space missions, neural mechanisms of heartrate regulation are still disturbed. After 1 month, autonomic control of heartrate recovered almost completely. PMID:23291736
Vandeput, Steven; Widjaja, Devy; Aubert, Andre E.; Van Huffel, Sabine
Safe monitoring of foetal heartrate 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 heartrate 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 heartrate 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 heartrate. 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
To obtain optimal training effects and avoid overtraining, it is necessary to monitor the intensity of training. In cycling, speed is not an accurate indicator of exercise intensity, and therefore alternatives have to be found to monitor exercise intensity during training and competition. Power output may be the most direct indicator, but heartrate is easier to monitor and measure. There are, however, limitations that have to be taken into account when using a heartrate monitor. For example, the position on the bicycle may change heartrate at a given exercise intensity. More important, however, is the increase in heartrate over time, a phenomenon described as 'cardiac drift'. Cardiac drift can change the heartrate-power output relationship drastically, especially in hot environments or at altitude. It is important to determine whether one is interested in monitoring exercise intensity per se or measuring whole-body stress. Power output may be a better indicator of the former and heartrate may, under many conditions, be a better indicator of the latter. Heartrate can be used to evaluate a cyclist after training or competition, or to determine the exercise intensity during training. Heartrate monitoring is very useful in the detection of early overtraining, especially in combination with lactate curves and questionnaires. During overtraining, maximal heartrates as well as submaximal heartrates may be decreased, while resting and, in particular, sleeping - heartrates may be increased. PMID:22587722
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Background. Acupuncture has been reported to affect the human autonomic system. Within this pilot study, teleacupuncture between China and Austria is used for the first time for quantifying the effects of heartrate variability (HRV) in poststroke rehabilitation. Methods. In 29 Chinese post-stroke patients (15 f, 14 m; mean age ± SD 64.7 ± 11.3 years; range 4080 years) electrocardiographic signals before, during, and after acupuncture at the acupoint Tongli (HT 5) were recorded in Harbin and analyzed in Graz using teleacupuncture via internet. HRV data were analyzed in the time and frequency domain, and a protocol from Austria was sent to the team in China immediately after the treatment and recording session. Results. Acupuncture does not change heartrate in the post-stroke patients; however, total HRV increased significantly (P teleacupuncture between China/Harbin and Austria/Graz over a distance of about 8,500 km is no longer a future vision; it has become reality. 1.
Lu Wang; Jan Valentini; Kazuo Sugimoto; Weiping Cheng; Guangyu Cheng; Haoming Geng; Ingrid Gaischek; Haixue Kuang; Gerhard Litscher
Investigated effects of 3 routine classroom arithmetic and reading tasks upon the heartrate reactivity of 30 fifth grade children. Results indicated that some children showed large increases in heartrates during the three tasks, and that these children should be considered at risk for coronary heart disease. (Author/TE)
The heartrate variability test gives an incredibly accurate view of the autonomic nervous systems and the variableness of the heart. It shows the state of relative health. Heartrate variability shows the correspondence between specific physiological components and the frequency spectrum. The two components are the sympathetic and parasympathetic neural systems, which originate in the brain and effect organs
Nutan D Ahuja; V. Raghavan; Vikas Lath; Ashish til; Sreejit Pillai
?-Adrenergic receptor (?AR) activation has been shown to maintain heartrate during hypoxia and to rescue the fetus from the fetal lethality that occurs in the absence of norepinephrine. This study examines whether the same subtype of ?AR is responsible for survival and heartrate regulation. It also investigates which ?ARs are located on the early fetal heart and whether
Rashmi Chandra; Andrea L. Portbury; Alisa Ray; Margie Ream; Marybeth Groelle; Dona M. Chikaraishi
Rationale We validated heartrate (HR) and six time and six frequency domain measures of heartrate variability (HRV) as estimators of autonomic outflow in 44 young healthy male subjects. Gold standards for autonomic outflow were the Rosenblueth-Simeone factors m (sympathetic tone) and n (vagal tone), and the sympathovagal balance m·n, determined by two-stage complete autonomic blockade. Methods Rank correlations were computed between HR and the HRV measures obtained before autonomic blockade, and m, n and m·n. Also, the maximal mean performances (averaged sensitivity and specificity) for HR and HRV as discriminators between low and high values of m, n or m·n were computed. Results The spectral HRV measures showed less good correlations and performances than the time domain HRV measures. Correlations with sympathetic tone were all below 0.31. Respiratory sinus arrhythmia during 15 cycles/min metronome breathing was superior in estimating vagal tone and sympathovagal balance (correlations -0.71/-0.73; both performances 0.82), heartrate scored similarly for assessing the sympathovagal balance (correlation 0.71; performance 0.82). Conclusions It does not appear justified to evaluate HR or HRV in terms of sympathetic tone, vagal tone, or sympathovagal balance. HR and HRV are specifically weak in assessing sympathetic tone. Respiratory sinus arrhythmia during 15 cycles/min metronome breathing is superior in assessing vagal tone. Current HRV analysis techniques offer no advantages compared with HR in assessing the sympathovagal balance.
Bootsma, M.; Swenne, C.A.; Janssen, M.J.A.; Cats, V. Manger; Schalij, M.J.
Heartrate variability, as determined from 24-hour Holter recordings, represents a noninvasive parameter for studying the autonomic control of the heart. It decreases with certain disease states characterized by autonomic dysfunction such as congestive heart failure. No study in healthy or cardiac children has been performed to determine the correlations between and within time and frequency domain indices of heartrate variability. We examined five time domain (SDNN, SDNNi, SDANNi, rMSSD and pNN50) and five frequency domain measures (ULF, VLF, LF, HF and balance LF/HF) in 200 healthy children and 200 children with congenital heart disease, aged 3 days to 14 years. All measures were significantly correlated with each other. However, the strength of correlation varied greatly. Our data show that variables strongly dependent on vagal tone (rMSSD, pNN50 and HF) were highly correlated (r value > 0.90), as well as SDNN and SDANNi. We conclude that certain time and frequency domain indices correlate so strongly with each other that they can act as surrogates for each other. PMID:10449882
Objective: To establish reference ranges for first trimester embryonic\\/fetal heartrate in normal pregnant women. Materials and methods: This was a cross-sectional study. We performed ultrasonogram in 319 normal pregnant women, gestation age between 6+0 and 14+6 weeks and measured embryonic\\/fetal heartrates using M-mode. The embryonic\\/fetal heartrates were analyzed according to gestational ages (GA). Results: Data of 319
To examine whether transfer of heartrate (HR) feedback training to tasks not used during training could be improved by using multiple tasks during training, a modified multiple baseline across tasks, single subject design study was conducted using six high HR-reactive young adults. Participants received HR feedback training during the presentation of a videogame, and transfer of training was assessed
Background Psoriasis is a systemic inflammatory disease associated with increased risk of cardiovascular diseases. The heartrate recovery index (HRRI) is an indicator of autonomic nervous system function and is an independent prognostic risk factor for cardiovascular diseases. The aim of this study was to evaluate the heartrate recovery indices in patients with psoriasis. Material/methods Thirty-three psoriasis patients (22 male; mean age 41±11 years) and 26 healthy individuals (15 male; mean age 39±11 years) as a control group were included in the study. Baseline electrocardiography, transthoracic echocardiographic examinations, and exercise stress tests were performed in psoriasis and control groups. The heartrate recovery of the psoriasis group at 1, 2, 3, 4, and 5 minutes after maximal exercise were calculated and compared to those of the control group. Results Baseline demographic and clinical characteristics of psoriasis and control groups including age, sex, body mass index, systolic blood pressure, and echocardiographic parameters were similar. Total cholesterol, low-density lipoprotein cholesterol, and triglyceride levels were significantly higher and high-density lipoprotein cholesterol levels were significantly lower in the psoriasis group (p<0.05). Heartrate recovery at 1, 2, 3, 4, and 5 minutes after maximal exercise were found to be significantly lower in the psoriasis group (p<0.05). Additionally, baseline heartrates before exercise were significantly higher in the psoriasis group (p<0.05). Conclusions We found that impaired HRRI in psoriasis patients, which indicates the underlying autonomic nervous system dysfunction, is a pathophysiologic mechanism for increased cardiovascular disease risk. PMID:24584215
Yuksel, Esra Pancar; Yuksel, Serkan; Yenercag, Mustafa; Soylu, Korhan; Aydin, Fatma; Senturk, Nilgun; Yucel, Huriye; Canturk, Tayyar; Turanli, Ahmet Y.
Choir singing is known to promote wellbeing. One reason for this may be that singing demands a slower than normal respiration, which may in turn affect heart activity. Coupling of heartrate variability (HRV) to respiration is called Respiratory sinus arrhythmia (RSA). This coupling has a subjective as well as a biologically soothing effect, and it is beneficial for cardiovascular function. RSA is seen to be more marked during slow-paced breathing and at lower respiration rates (0.1 Hz and below). In this study, we investigate how singing, which is a form of guided breathing, affects HRV and RSA. The study comprises a group of healthy 18 year olds of mixed gender. The subjects are asked to; (1) hum a single tone and breathe whenever they need to; (2) sing a hymn with free, unguided breathing; and (3) sing a slow mantra and breathe solely between phrases. Heartrate (HR) is measured continuously during the study. The study design makes it possible to compare above three levels of song structure. In a separate case study, we examine five individuals performing singing tasks (1-3). We collect data with more advanced equipment, simultaneously recording HR, respiration, skin conductance and finger temperature. We show how song structure, respiration and HR are connected. Unison singing of regular song structures makes the hearts of the singers accelerate and decelerate simultaneously. Implications concerning the effect on wellbeing and health are discussed as well as the question how this inner entrainment may affect perception and behavior. PMID:23847555
This study investigated alterations in heartrate variability (HRV) and cognitive performance before and after physical effort, for 30 high-level track and field athletes (23 males and 7 females). Interbeat intervals were assessed at the baseline and during each task of a CogState cognitive battery (simple reaction time, choice reaction time, working memory, short-term memory and sustained attention). Time and
Caroline Di Bernardi Luft; Emílio Takase; David Darby
The major goal of the current study was to investigate the association between continuous performance tests (CPTs) and the heartrate variability (HRV) of attention deficit hyperactivity disorder (ADHD) children. The HRV, specifically the 0.10-Hz component, may be considered to be a psychophysiological index of effort allocation (motivation): The less effort the subject allocates, the greater the 0.10-Hz component. Results
Norbert Börger; Jaap van Der Meere; Arjen Ronner; Ed Alberts; Reint Geuze; Hans Bogte
We studied 54 patients with hypoxemic chronic obstructive pulmonary disease (COPD). The Mini Mental State Examination and the Mental Deterioration Battery were used for neuropsychological assessment. Heartrate variability (HRV) was assessed based on 24-h Holter ECG recording. MannWhitney test was used to compare HRV parameters of patients performing normally or abnormally on individual neuropsychological tasks. Spearmans rho was used
Raffaele Antonelli Incalzi; Andrea Corsonello; Luigi Trojano; Claudio Pedone; Domenico Acanfora; Aldo Spada; Gianni DAddio; Roberto Maestri; Franco Rengo; Giuseppe Rengo
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 heartrate 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.
In this paper, the gHRV software tool is presented. It is a simple, free and portable tool developed in python for analysing heartrate 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 heartrate 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
To quantitatively determine the extent to which a given heartrate correlates with the following heartrate(s) at any gestational age, we studied 181 uncomplicated human fetuses between 23 and 41 weeks gestation. A continuous 90120 min observation was made for each case using external Doppler-ultrasound cardiotocography. For every individual fetal heartrate dataset, probability distribution matrices were calculated with
HEARTRATE AS A MONITOR FOR METABOLIC RATE IN CAPTIVE JUVENILE STELLER SEA LIONS (EUMETOPIAS COLUMBIA 0Jan M. Mcl'hee, 2001 #12;ABSTRACT The potential use of heartrate to monitor energy expenditure a relationship exists between heartrate @I) and oxygen consumption ( ~ 0 ~ )in captive sea lions while swimming
When regulating negative emotional reactions, one goal is to reduce physiological reactions. However, not all regulation strategies succeed in doing that. We tested whether heartrate biofeedback helped participants reduce physiological reactions in response to negative and neutral pictures. When viewing neutral pictures, participants could regulate their heartrate whether the heartrate feedback was real or not. In contrast, when viewing negative pictures, participants could regulate heartrate only when feedback was real. Ratings of task success paralleled heartrate. Participants' general level of anxiety, emotion awareness, or cognitive emotion regulation strategies did not influence the results. Our findings show that accurate online heartrate biofeedback provides an efficient way to down-regulate autonomic physiological reactions when encountering negative stimuli. PMID:24373886
Complex phenomena know several benchmarks, or hard and to date unsatisfactorily understood problems. Human heartrate control\\u000a is such a complexity benchmark in biophysics, consistently defying full explanation. In our recent work, heartrate regulation\\u000a by the autonomic nervous system has been shown to display remarkable fundamental properties of scale-invariance of extreme\\u000a value statistics  in healthy heartrate fluctuations,
Ken Kiyono; Yoshiharu Yamamoto; Zbigniew R. Struzik
Heartrate influences myocardial oxygen demand, coronary blood flow, and myocardial function. Clinical and experimental studies\\u000a support an association between elevated resting heartrate and a broad range of maladaptive effects on the function and structure\\u000a of the cardiovascular system. Heartrate has been shown to be an important predictor of mortality in cardiovascular disorders\\u000a such as coronary artery disease,
Jan-Christian Reil; Florian Custodis; Karl Swedberg; Michel Komajda; Jeffrey S. Borer; Ian Ford; Luigi Tavazzi; Ulrich Laufs; Michael Böhm
Numerous studies have shown that resting heartrate is closely correlated with blood pressure and that it is prospectively\\u000a related to the development of hypertension. Moreover, there is mounting evidence to indicate that a high heartrate is associated\\u000a with increased cardiovascular morbidity and mortality. In this respect, heartrate can be considered both as a marker of risk\\u000a and
Heartrate was recorded from 3 age groups (8-10, 12, and 20-26 years) while they performed a probabilistic learning task. Stimuli had to be sorted by pressing a left versus right key, followed by positive or negative feedback. Adult heartrate slowed following negative feedback when stimuli were consistently mapped onto the left or right key
Crone, Eveline A.; Jennings, J. Richard; Van der Molen, Maurits W.
The effect of one-year physical training on heartrate variability in older adults was evaluated in 14 healthy men (age > 55 year). Measures of heartrate variability were obtained in both time and frequency domain. Ten- minute ECG recordings were made in supine position and in standing position. A progressive climbing exertion test till exhaustion was performed to estimate
Sympathetic and parasympathetic activity was evaluated on 39 occasions in 17 patients with the sepsis syndrome, by measurement of the variation in resting heartrate using frequency spectrum analysis. Heartrate was recorded by electrocardiography and respiratory rate by impedance plethysmography. The sepsis syndrome was established on the basis of established clinical and physiological criteria. Subjects were studied, whenever possible,
Christopher S. Garrard; Dimitrios A. Kontoyannis; Massimo Piepoli
Abstract Objectives. In the clinical setting, patients with slower resting heartrate are less prone to cardiovascular death compared with those with elevated heartrate. However, electrophysiological adaptations associated with reduced cardiac rhythm have not been thoroughly explored. In this study, relationships between intrinsic heartrate and arrhythmic susceptibility were examined by assessments of action potential duration (APD) rate adaptation and inducibility of repolarization alternans in sinoatrial node (SAN)-driven and atrioventricular (AV)-blocked guinea-pig hearts perfused with Langendorff apparatus. Design. Electrocardiograms, epicardial monophasic action potentials, and effective refractory periods (ERP) were assessed in normokalemic and hypokalemic conditions. Results. Slower basal heartrate in AV-blocked hearts was associated with prolonged ventricular repolarization during spontaneous beating, and with attenuated APD shortening at increased cardiac activation rates during dynamic pacing, when compared with SAN-driven hearts. During hypokalemic perfusion, the inducibility of repolarization alternans and tachyarrhythmia by rapid pacing was found to be lower in AV-blocked hearts. This difference was ascribed to prolonged ERP in the setting of reduced basal heartrate, which prevented ventricular capture at critically short pacing intervals required to induce arrhythmia. Conclusions. Reduced basal heartrate is associated with electrophysiological changes that prevent electrical instability upon an abrupt cardiac acceleration. PMID:25334079
Heartrate (HR) variability (HRV; beat-to-beat changes in the R-wave to R-wave interval) has attracted considerable attention during the past 30+ years (PubMed currently lists >17 000 publications). Clinically, a decrease in HRV is correlated to higher morbidity and mortality in diverse conditions, from heart disease to fetal distress. It is usually attributed to fluctuation in cardiac autonomic nerve activity. We calculated HRV parameters from a variety of cardiac preparations (including humans, living animals, Langendorff-perfused heart, and single sinoatrial nodal cell) in diverse species, combining this with data from previously published articles. We show that regardless of conditions, there is a universal exponential decay-like relationship between HRV and HR. Using 2 biophysical models, we develop a theory for this and confirm that HRV is primarily dependent on HR and cannot be used in any simple way to assess autonomic nerve activity to the heart. We suggest that the correlation between a change in HRV and altered morbidity and mortality is substantially attributable to the concurrent change in HR. This calls for re-evaluation of the findings from many articles that have not adjusted properly or at all for HR differences when comparing HRV in multiple circumstances. PMID:25225208
Monfredi, Oliver; Lyashkov, Alexey E; Johnsen, Anne-Berit; Inada, Shin; Schneider, Heiko; Wang, Ruoxi; Nirmalan, Mahesh; Wisloff, Ulrik; Maltsev, Victor A; Lakatta, Edward G; Zhang, Henggui; Boyett, Mark R
We report the first measurements of heartrate (fH) and the rate of oxygen consumption (V?O2) during flights from a species of bird larger than 500 g. V?O2was obtained from nine forward flapping flights of 8.9 min mean duration at a mean speed of 13.2 m s?1 performed by three barnacle geese of mean mass 1.68 kg. Mean V?O2was 332
P. J Butler; A. J Woakes; R. M Bevan; R Stephenson
Chronic heartrate reduction with ivabradine improves systolic function of the reperfused heart function and calcium handling to chronic heartrate reduction with ivabradine in the reperfused heartheartrate by about 20% and improved both ejection fraction (+35%) and systolic displacement (+26
This guide discusses the assessment of heartrate and, in particular, the assessment of heartrate using a heart monitor. Part 1, "Foundation for the Use of HeartRate," reviews literature about heartrate assessment and heartrate monitors, offering an overview of national guidelines for physical activity. It focuses on the importance of physical
Should teachers teach the calculation of target heartrate to students? And when is it appropriate to engage students in the attainment of these heartrates during physical education class activities? The answers to these questions are not easy. One might be tempted to state a simple yes or no and to identify a specific age to begin using training
Objective: To investigate how playing a violent\\/nonviolent television game during the evening affects sympathetic and parasympathetic reactions during and after playing as well as sleep quality during the night after playing. Subjects and Methods: In total, 19 boys, 12-15 years of age, played television games on two occasions in their homes and participated once without gaming. Heartrate, heartrate
Malena Ivarsson; Martin Anderson; Torbjörn Åkerstedt; Frank Lindblad
Demonstrates the therapeutic effectiveness of heartrate control training in the treatment of a phobia. The S was a male college student who experienced a high degree of anxiety in association with receiving injections. S received 14 1-hr sessions of biofeedback training over the course of 2 mo and was encouraged to practice heartrate control between sessions. A time-series
Small beat-to-beat differences in heartrate are the result of dynamic control of the cardiovascular system by the sympathetic and parasympathetic nervous systems. Heartrate variability (HRV) has been positively correlated with both mental and physical health. While many studies measure HRV under rest conditions, few have measured HRV during stressful situations. We describe an experimental protocol designed to measure
In an experiment with 16 male undergraduates, Ss receiving high shock were considerably more autonomically aroused than low shock Ss, as indicated both by an index of GSR, and by heartrate uncorrected for base level. When corrected, heartrate did not differentiate between Ss receiving high and low level shock. In a within Ss comparison, however, UCS temporal uncertainty
Anxiety may worsen outcome in psychotic disorders. We assessed anxiety in 44 acutely psychotic subjects and found a positive association with heartrate and blood pressure. Risperidone treatment reduced anxiety but increased heartrate. We concluded that anxiety may adversely affect cardiovascular status in schizophrenia, but the anxiolytic effect of risperidone is not straightforward.
Mark H. Townsend; Margaret B. Baier; Jonathan E. Becker; Mark A. Ritchie
Technical Note Brain correlates of autonomic modulation: Combining heartrate variability with f-gated fMRI timeseries with continuous- time heartrate variability (HRV) to estimate central autonomic pro T1-variability, which was corrected by transforming fMRI data to a fixed TR using a previously
Loss of normal autonomic nervous system control of heartrate and rhythm is an important risk factor for adverse cardiovascular events. After myocardial infarction, reduction in beat-to-beat heartrate variability, a measure of cardiac autonomic innervation by the brain, is a strong predictor of death. With loss of vagal innervation, as is noted in patients with severe neuropathy and in
We report extremely prominent heartrate oscillations associated with slow breathing during specific traditional forms of Chinese Chi and Kundalini Yoga meditation techniques in healthy young adults. We applied both spectral analysis and a novel analytic technique based on the Hilbert transform to quantify these heartrate dynamics. The amplitude of these oscillations during meditation was significantly greater than in
C.-K Peng; Joseph E Mietus; Yanhui Liu; Gurucharan Khalsa; Pamela S Douglas; Herbert Benson; Ary L Goldberger
Ultrasound fetal heartrate monitoring is very useful to determine the status of the fetus because it is noninvasive. In order to ensure the accuracy of the fetal heartrate (FHR) obtained from the ultrasound Doppler data, we measure the fetal electrocardiogram (ECG) directly and obtain the Doppler data simultaneously. The FHR differences of the Doppler data from the direct
Background: Epidemiologic studies have linked fine particulate air pollution with cardiopulmonary mortality, yet underlying biologic mechanisms remain unknown. Changes in heartrate variability (HRV) may reflect changes in cardiac autonomic function and risk of sudden cardiac death. This study evaluated changes in mean heartrate and HRV in human beings associated with changes in exposure to particulate air pollution. Methods:
C. Arden Pope; Richard L. Verrier; Eric G. Lovett; Andrew C. Larson; Mark E. Raizenne; Richard E. Kanner; Joel Schwartz; G. Martin Villegas; Diane R. Gold; Douglas W. Dockery
The aim of the present study was to examine gender-related differences in heartrate of human neonates controlled for their behavior. Previous studies could not find any difference in male and female fetuses and newborns, although this gender- dependent difference clearly exists in children and adults. The heartrate of 99 newborns (47 girls and 52 boys) was measured with
EMESE NAGY; HAJNALKA ORVOS; GYORGY BARDOS; PETER MOLNAR
To assess the relationship between heartrate and defecation frequency as comparable measures of emotionality, both were recorded simultaneously from albino rats in a novel environment and in the home cage. Subgroups receiving different numbers of trials were used under both environmental conditions to distinguish the possible effects of distribution of trials and age. Heartrate and defecation frequency were
Douglas K. Candland; Kenneth D. Pack; T. James Matthews
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 heartrate (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 heartrate 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.
Heartrate and reactivity from pulse and ECG were compared over rest and mental arithmetic periods of 2-min duration each for 32 males and 50 females. Data from the two sources of heartrate were not significantly different during the rest period but did differ significantly during periods of heartrate acceleration and deceleration. Sex effects were also noted, with
1. Implanted ECG transmitters were used to determine heartrates 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 heartrates returned to pre-dive levels if the dive lasted greater than 30 sec. 3. Heartrates 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 heartrate values were higher than would be expected based on general energetic equations if we assume heartrate to be reflective of energy costs. This was considered to be a function of this species' fusiform body shape. PMID:6128113
In recent years there has been substantial support for heartrate variability biofeedback (HRVB) as a treatment for a variety of disorders and for performance enhancement (Gevirtz, 2013). Since conditions as widely varied as asthma and depression seem to respond to this form of cardiorespiratory feedback training, the issue of possible mechanisms becomes more salient. The most supported possible mechanism is the strengthening of homeostasis in the baroreceptor (Vaschillo et al., 2002; Lehrer et al., 2003). Recently, the effect on the vagal afferent pathway to the frontal cortical areas has been proposed. In this article, we review these and other possible mechanisms that might explain the positive effects of HRVB. PMID:25101026
Purpose Heartrate recovery (HRR) after treadmill exercise testing is an index of cardiac autonomic activity in non-disabled persons,\\u000a but it is unknown if this is also the case in individuals with spinal cord injury (SCI). We investigated the relationship\\u000a between HRR after maximal arm exercise testing and resting autonomic activity in persons with paraplegia.\\u000a \\u000a \\u000a \\u000a \\u000a Methods A total of 17 (male n = 9,
Sae Young Jae; Kevin S. Heffernan; Miyoung Lee; Bo Fernhall
During everyday life, gravity constantly stresses the human circulation by diminishing venous return in the upright position. This induces baroreflex-mediated cardiovascular adjustments that are aimed to prevent the blood pressure from falling. In weightlessness, gravitational pressure gradients do not arise in the circulation so that baroreflex function remains chronically unchallenged. This may contribute to the development of post spaceflight orthostatic intolerance. The purpose of this study was to evaluate respiratory modulation and baroreflex control of heartrate after a week of weightlessness in space. We tested the hypothesis that cardiovascular control in space will be similar to the baseline supine condition on Earth. We studied nine male cosmonauts during seven different space missions aboard the ISS (age 40 - 52 yrs, height 1.69 - 1.85 m, weight 67 - 90 kg). Data collection was performed between 30 and 45 days before launch in the standing and supine positions, and after 8 days in space. Cosmonauts were carefully trained to perform in-flight data collection by themselves. They were instructed to pace their breathing to a fixed rate of 12 breaths per minute (0.2 Hz) for a total duration of 3 minutes. The electrocardiogram and beat-by-beat finger arterial blood pressure were recorded at 1-kHz sample rate. Respiratory rate was evaluated using an abdominal pressure sensor. We used power spectral analysis to calculate respiratory sinus arrhythmia (RSA) as well as the low-frequency (0.04 - 0.15 Hz) powers of spontaneous oscillations in heartrate and systolic blood pressure. Baroreflex sensitivity (BRS) was estimated in the time domain using cross-correlation analysis. As expected, there was a rise in heartrate upon assuming the standing position before space- flight (59 ± 6 to 79 ± 11 beats per min; p ¡ 0.001). This was accompanied by an increase in mean arterial blood pressure (84 ± 6 to 93 ± 6 mmHg; p ¡ 0.001). Standing up further induced a marked increase in the low-frequency powers of systolic blood pressure oscillations (8 ± 7 to 17 ± 11 mmHg2; p = 0.018), whereas those in heartrate remained unchanged (445 ± 512 to 621 ± 799 ms2; p = 0.315). Alternatively, there was a reduction in RSA from 546 ± 167 ms2 to 158 ± 298 ms2 and in spontaneous BRS from 14 ± 5 ms/mmHg to 6 ± 2 ms/mmHg upon changing from supine to standing (both p ¡ 0.001). After a week of weightlessness in space, heartrate (61 ± 8 beats per min) and mean blood pressure (83 ± 6 mmHg) returned to the pre-flight supine values. This was also true for the low-frequency powers of systolic blood pressure (7 ± 4 mmHg2) and of heartrate (741 ± 716 ms2), as well as for RSA (465 ± 269 ms2) and spontaneous BRS (14 ± 4 ms/mmHg). It is concluded that cardiovascular control after one week in space corresponds to the pre-flight supine condition. This is characterized by a chronically increased vagal-cardiac outflow and suppressed sympathetic vasomotor modulation compared with the standing position on Earth. This kind of chronic baroreflex unloading is likely to contribute to post-spaceflight functional impairment of orthostatic blood pressure control.
Verheyden, Bart; Couckuyt, Kurt; Liu, Jiexin; Aubert, Andre
Several formulas have been proposed to adjust the QT interval for heartrate, the most commonly used being the QT correction formula (QTc = QT\\/square root of RR) proposed in 1920 by Bazett. The QTc formula was derived from observations in only 39 young subjects. Recently, the adequacy of Bazett's formula has been questioned. To evaluate the heartrate QT
Alex Sagie; Martin G. Larson; Robert J. Goldberg; James R. Bengtson; Daniel Levy
Forty-one Dutch Warmblood immature horses were used in a study to quantify temperamental traits on the basis of heartrate (HR) and heartrate variability (HRV) measures. Half of the horses received additional training from the age of 5 months onwards; the other half did not. Horses were tested at 9, 10, 21 and 22 months of age in a
E. K. Visser; C. G. van Reenen; M. B. H. Schilder; J. H. Knaap; A. Barneveld; H. J. Blokhuis
Resting heartrate variability can be an index of sympathetic or parasympathetic dominance, according to the frequency of the variability studied. Sympathetic dominance of this system has been linked to increased risk of cardiovascular disease (CVD). Similarly, rapid and dramatic increases in heartrate reactivity to a stressor task have also been suggested as indicating increased risk of CVD via
Christopher F. Sharpley; Peter Kamen; Maria Galatsis; Rod Heppel; Charles Veivers; Kim Claus
Heartrate and locomotor activity of rats kept under 12L/12D illumination regimen were recorded every six minutes for ten days using implantable radio transmitters. Some of the rats then received bilateral RF lesions into the suprachiasmatic nucleus (SCN). Control sham operations were performed on the rest of the animals. After recovery from surgery, recording of heartrate and locomotor activity was continued for ten days. SCN-lesioned rats showed no significant diurnal fluctuation in heartrate, while normal and sham-operated rats showed the normal diurnal rhythm in that function. The arrhythmic diurnal heart-rate pattern of SCN rats appeared to be correlated with their sporadic activity pattern. The integrity of the suprachiasmatic nucleus is therefore necessary for the generation and/or expression of diurnal rhythmicity in heartrate in the rat.
the effects on heartrate and oxygen saturation of transitioning from positive pressure breathing for increased Gz load to positive pressure breathing for altitude. Analysis was performed on previously recorded data taken with permission from Brooks United...
We investigated why resting heartrate is elevated in dogs fed a high saturated fat diet for 12.7 +/- 1.8 wk. Obese dogs exhibited elevated body weight (59%), blood pressure (14%), and heartrate (25%). Differences in resting heartrate (control, 58 +/- 5 beats/min; obese, 83 +/- 7 beats/min) were abolished after hexamethonium, indicating an autonomic mechanism. Hexamethonium also reduced blood pressure in obese (20 +/- 4 mmHg) but not control (9 +/- 6 mmHg) animals. Propranolol did not affect heartrate in either group, excluding a beta-adrenergic mechanism. Subsequent administration of atropine increased heartrate more in control than in obese dogs (110 +/- 9 vs. 57 +/- 11 beats/min). The sensitivity of the cardiac limb of the baroreflex (Oxford method) was reduced by 46% in the obese group, confirming impairment of the parasympathetic control of heartrate. The standard deviation of blood pressure measurements was normal when expressed as a percentage of the mean arterial blood pressure (control, 11.2 +/- 0.4%; obese, 11.2 +/- 0.5%). Our results indicate that the development of obesity in dogs fed a high saturated fat diet is accompanied by an attenuated resting and reflex parasympathetic control of heartrate. PMID:7653627
Van Vliet, B N; Hall, J E; Mizelle, H L; Montani, J P; Smith, M J
Experience with frequency domain analysis over the past two decades strongly suggests that it represents a unique, noninvasive tool for achieving a more precise assessment of autonomic function in both the experimental and clinical settings. Available studies indicate that the significance of the HF component is far better understood than that of the lower frequency components. In general, it is considered to reflect vagal activity, and because it is readily manipulated pharmacologically, is used as a an index of that activity. However, some caution is required because this parameter also is strongly influenced by the degree of coupling between respiration and heartrate, which, in turn, reflects the intensity of the respiratory effort as well as of parasympathetic activity. Respiratory pattern also can significantly influence HF power. The use of controlled breathing minimizes these problems, improves reproducibility of test findings, and also facilitates quantitative comparisons. The situation with respect to LF power is more complicated because it is modulated by both sympathetic and parasympathetic outflows (see previous discussion) as well as by other factors, including baroreceptor activity. Therefore, LF analysis per se cannot afford a precise delineation of the state of sympathetic activation. Determinations of the LF/HF ratio, an index of sympathovagal balance both under control conditions and in conjunction with interventions that maximize sympathetic and parasympathetic activity, provide additional insights, as do correlations between spectral activity and direct nerve recordings, plasma norepinephrine concentrations, and radionuclide imaging of adrenergic nerves. Renewed interest has recently been evinced in frequencies lower than 0.04 Hz in view of reports that the VLF portion of the spectrum (0.01-0.04 Hz) reflects a purer form of sympathetic activity than does the LF band. Despite the potential applicability to clinical problems, only very little is known about the physiologic basis of the VLF and ULF bands. Further study is required. However, it is important to note that meaningful determinations of VLF and ULF power may be difficult because decreases in frequency to such low levels are associated with an increasing propensity to violate the rules governing power spectral determinations (see previous discussion and appendix), violations that diminish reliability despite the most sophisticated preprocessing. It is also noteworthy that the reliability of spectral power determinations diminishes with decreases in the power of the signal and of the signal-to-noise ratio.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:1504981
Ori, Z; Monir, G; Weiss, J; Sayhouni, X; Singer, D H
We studied visual discrimination learning in a group of Nigerian dwarf goats using a computer-based learning device which was integrated in the animals' home pen. We conducted three consecutive learning tasks (T1, T2 and T3), each of which lasted for 13 days. In each task, a different set of four visual stimuli was presented on a computer screen in a four-choice design. Predefined sequences of stimulus combinations were presented in a pseudorandom order. Animals were rewarded with drinking water when they chose the positive stimulus by pressing a button next to it. Noninvasive measurements of goats' heartbeat intervals were carried out on the first and the last 2 days of each learning task. We analysed heartrate (HR) and heartrate variability (HRV) of resting animals to study sustained physiological effects related to general learning challenge rather than acute excitement during an actual learning session. The number of trials to reach the learning criterion was 1000 in T1, when visual stimuli were presented to the goats for the first time, but decreased to 210 in T2 and 240 in T3, respectively. A stable plateau of correct choices between 70% and 80% was reached on Day 10 in T1, on Day 8 in T2 and on Day 6 in T3. We found a significant influence of the task and of the interaction between task and day on learning success. Whereas HR increased throughout T1, this relationship was inverted in T2 and T3, indicating different effects on the HR depending on how familiar goats were with the learning task. We found a significant influence of the task and the interaction between task and time within the task on HRV parameters, indicating changes of vagal activity at the heart. The results suggest that changes in HR related to learning were predominantly caused by a withdrawal of vagal activity at the heart. With regard to nonlinear processes in heartbeat regulation, increased deterministic shares of HRV indicated that the animals did not really relax until the end of T3. Comparing changes of HR and HRV in T3 and in a subsequent postexperiment (PE), we assume a positive effect of such cognitive challenges once the task had been learned by the animals. PMID:15327907
Kava, which grows throughout the Pacific Islands, was used by Polynesians in ceremonies and is now used as a recreational drug. Because of its current popularity, concern is rising about the health effects of kava when taken with other drugs. Results of the few studies done on the effects of kava on the heart are unclear; this study was conducted
The arguments are given that local exponents obtained in multifractal analysis by two methods: wavelet transform modulus maxima (WTMM) and multifractal detrended fluctuation analysis (MDFA) allow to separate statistically hearts of healthy people and subjects suffering from reduced left ventricle systolic function (NYHA IIII class). Proposed indices of fractality suggest that a signal of human heartrate is a mixture
Danuta Makowiec; Aleksandra Dudkowska; Andrzej Rynkiewicz; Marcin Zwierz
Although essential hypertension seems to have a strong hereditary component, the triggering mechanism is unclear. It is likely that the central nervous system via autonomic sympathetic overactivation plays a key role in the development of hypertension. High heartrate has proven to be a strong predictor for cardiovascular disease and a predictor of the development of essential hypertension. Because heart
Trygve B. Tjugen; Arnljot Flaa; Sverre E. Kjeldsen
The analysis of heartrate variability (HRV) is becoming widely used in clinical research to provide a window into autonomic control of HR. This technique has been valuable in elucidating the autonomic underpinnings of panic disorder (PD), a condition that is marked by reports of heart palpitations. A body of research has emerged that implicates a relative reduction in HRV
A healthy human heartrate displays complex fluctuations which share characteristics of physical systems in a critical state. We demonstrate that the human heartrate in healthy individuals undergoes a dramatic breakdown of criticality characteristics, reminiscent of continuous second order phase transitions. By studying the germane determinants, we show that the hallmark of criticalityhighly correlated fluctuationsis observed only during usual daily activity, and a breakdown of these characteristics occurs in prolonged, strenuous exercise and sleep. This finding is the first reported discovery of the dynamical phase transition phenomenon in a biological control system and will be a key to understanding the heartrate control system in health and disease.
A case is presented revealing the common phenomenon of heartrate-dependent diagnosis of electrocardiographic (ECG) diagnosis of left ventricular hypertrophy (LVH), which consists of satisfaction of LVH criteria only at faster rates whereas ECGs with a slow heartrate do not satisfy such criteria. The mechanism of the phenomenon has been attributed to the tachycardia-mediated underfilling of the left ventricle bringing the electrical "centroid" of the heart closer to the recording electrodes, which results in augmentation of the amplitude of QRS complexes, particularly in leads V2-V4. PMID:22519574
1. Heartrates 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 heartrates following diving, average swimming heartrates 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 heartrates than did warmer temperatures (approximately 20 degrees C) in active, non-diving behaviors (P less than 0.05). PMID:2906827
Eur Heart J. Author manuscript Page /1 9 History of coronary heart disease and cognitive for this association. Coronary heart disease is a global problem, with the risk of disease shown to increase as12 heart disease (CHD) and cognitive performance in middle-aged adults. The evidence for this association
Background Heart failure (HF) is a syndrome that leads to poor outcome in advanced forms. The neurohormonal blockade modifies this natural history; however, it is often suboptimal. Objective The aim of this study is to assess at what percentage cardiologists used to treating HF can prescribe target doses of drugs of proven efficacy. Methods A total of 104 outpatients with systolic dysfunction were consecutively enrolled, all under stabilized treatment. Demographic and treatment data were evaluated and the doses achieved were verified. The findings are shown as percentages and correlations are made between different variables. Results The mean age of patients was 64.1 ± 14.2 years, with SBP =115.4 ± 15.3, HR = 67.8 ± 9.4 bpm, weight = 76.0 ± 17.0 kg and sinus rhythm (90.4%). As for treatment, 93.3% received a RAS blocker (ACEI 52.9%), all received beta-blockers (BB), the most often prescribed being carvedilol (92.3%). As for the doses: 97.1% of those receiving an ARB were below the optimal dose and of those who received ACEI, 52.7% received an optimized dose. As for the BB, target doses were prescribed to 76.0% of them. In this group of patients, most with BB target dose, it can be seen that 36.5% had HR ? 70 bpm in sinus rhythm. Conclusion Cardiologists used to treating HF can prescribe target doses of ACEI and BB to most patients. Even though they receive the recommended doses, about one third of patients persists with HR > 70 bpm and should have their treatment optimized. PMID:24100693
Moreno, Irineu Blanco; Del Carlo, Carlos Henrique; Pereira-Barretto, Antonio Carlos
Background b-Blockade-induced benefit in heart failure (HF) could be related to baseline heartrate and treatment- induced heartrate reduction, but no such relationships have been demonstrated. Methods and ResultsIn CIBIS II, we studied the relationships between baseline heartrate (BHR), heartrate changes at 2 months (HRC), nature of cardiac rhythm (sinus rhythm or atrial fibrillation), and outcomes (mortality
We focus on various measures of the fluctuations of the sequence of intervals between beats of the human heart, and how such fluctuations can be used to assess the presence or likelihood of cardiovascular disease. We examine sixteen such measures and their suitability for correctly classifying heartbeat records of various lengths as normal or revealing the presence of cardiac dysfunction, particularly congestive heart failure. Using receiver-operating-characteristic analysis we demonstrate that scale-dependent measures prove substantially superior to scale-independent ones. The wavelet-transform standard deviation at a scale near 32 heartbeat intervals, and its spectral counterpart near 1/32 cycles/interval, turn out to provide reliable results using heartbeat records just minutes long. We further establish for all subjects that the human heartbeat has an underlying stochastic origin rather than arising from a chaotic attractor. Finally, we develop a mathematical point process that emulates the human heartbea...
Teich, M C; Jost, B M; Vibe-Rheymer, K; Heneghan, C; Teich, Malvin C.; Lowen, Steven B.; Jost, Bradley M.; Vibe-Rheymer, Karin; Heneghan, Conor
We focus on various measures of the fluctuations of the sequence of intervals between beats of the human heart, and how such fluctuations can be used to assess the presence or likelihood of cardiovascular disease. We examine sixteen such measures and their suitability for correctly classifying heartbeat records of various lengths as normal or revealing the presence of cardiac dysfunction, particularly congestive heart failure. Using receiver-operating-characteristic analysis we demonstrate that scale-dependent measures prove substantially superior to scale-independent ones. The wavelet-transform standard deviation at a scale near 32 heartbeat intervals, and its spectral counterpart near 1/32 cycles/interval, turn out to provide reliable results using heartbeat records just minutes long. We further establish for all subjects that the human heartbeat has an underlying stochastic origin rather than arising from a chaotic attractor. Finally, we develop a mathematical point process that emulates the human heartbeat time series for both normal subjects and heart-failure patients.
Malvin C. Teich; Steven B. Lowen; Bradley M. Jost; Karin Vibe-Rheymer; Conor Heneghan
IntroductionCurrent evidence suggests that heartrate (HR) may serve both as a modifiable risk factor, and as a disease modifying variable in patients with impaired left ventricular (LV) systolic function. The systolic heart failure (HF) treatment with If inhibitor ivabradine trial (SHIFT) for example recently demonstrated significantly improved outcomes in otherwise optimally treated HF patients following additional HR reduction with
S Russell; M Oliver; H Rose; J Davies; H Llewellyn-Griffiths; A Raybould; V Sim; Z R Yousef
Background Decreased heartrate variability (HRV), indicating derangement in cardiac autonomic control, has been reported in patients with chronic heart failure. However, the independent and incremental prognostic value of HRV over clinical data and measures of left ventricular dysfunction has been less thoroughly investigated. This study was designed to evaluate the predictive value of HRV and Poincaré plots as assessed
Domenico Bonaduce; Mario Petretta; Fortunato Marciano; Maria L. E. Vicario; Claudio Apicella; Maria A. E. Rao; Emanuele Nicolai; Massimo Volpe
Background: The ability to better predict outcome with exercise testing in patients with heart failure (HF) and left ventricular systolic dysfunction (LVSD) may prove extremely valuable in determining which patients are at increased risk. This study evaluated the ability of heartrate recovery (HRR) to predict outcome in patients with HF and validate previous findings in LVSD. Methods and Results:
MICHAEL J. LIPINSKI; GEORGE W. VETROVEC; DMITRY GORELIK; VICTOR F. FROELICHER
The aim of our study was to compare the responses of heartrate variability (HRV) with two different types of hormonal substitution therapy (HT) in post-menopausal women (cross-sectional study) and to reveal an effect of HT shortly after beginning of its administration (follow-up study). To elucidate the influence of menopause and effects of different protocols of a HT on autonomic control of heartrate, we evaluated the heartrate variability (HRV) in 5 groups: premenopausal women (n=140), postmenopausal women without HT (n=360), women on HT with conjugated estrogen only (n=168), women on continuous combined estrogen-progesterone HT (n=117), and men (n=140). Frequency-domain of short-term stationary R-R intervals was performed to evaluate the total variance, low frequency power (LF; 0.04-0.15 Hz), high frequency power (HF; 0.15-0.40 Hz), portion of low frequency power (LF%) and ratio of LF to HF (LF/HF). Significantly lower portion of the LF was found in premenopausal women [46.9 (+/-2.7) nu] when compared to untreated postmenopausal women [54.3 (+/-2.9) nu] and men [55.2 (+/-3.0) nu]. Treatment by estrogen only was proved to decrease the LF% [40.1 (+/-2.1) nu] while no effect on HRV was observed in women treated with combination of estrogen and progesterone [57.2 (+/-3.1) nu]. Also the HF was lower in postmenopausal women [4.16 (+/-0.16) ms(2)] than in premenopausal women [4.79 (+/-0.22) ms(2)] and women treated with estrogen only [4.98 (+/-0.25) ms(2)] while in women treated with combined hormonal therapy the average value [3.99 (+/-0.21) ms(2)] did not significantly differ from that of untreated postmenopausal women. The follow-up study also proved increase of high frequency power already after two months of estrogen substitution therapy [4.86 (+/-0.14) ms(2) vs. 4.19 (+/-0.15) ms(2)]. These results suggest that higher vagal modulation of heartrate that seems typical for younger women becomes after menopause similar to that of men. We also proved a positive shift of HRV parameters toward more beneficial values as for a cardiovascular risk in postmenopausal women treated with estrogens but not in those treated by combined estrogen - progesterone substitution therapy. PMID:24329696
It was concluded that playing squash is an activity that results in heartrate responses of sufficient intensity to elicit aerobic training effects without producing high lactic acid concentration in the blood. (MM)
A variable heartbeat was considered a sign of good health by ancient Asian physicians. Today, new computer-based methods (e.g., "Fire of Life" analysis) allow quantification of heartrate and heartrate variability during acupuncture. The objective of this article is to compare different acupuncture methods to evaluate the influence of acupuncture on heart rhythm in short-term and long-term measurements. There were four main sections in this study: (A) a randomized controlled study using needle acupuncture and acupressure at Yintang (Ex1); (B) an innovative blue (violet) laser acupuncture randomized controlled study in Asian volunteers; (C) a comparative study using moxibustion methods; and (D) teleacupuncture. A total of 72 patients (mean age ± SD: 27.9 ± 8.6 years) were monitored over periods of 20 minutes to 24 hours in Asia and Austria. Acupuncture was performed with metal needles (in sections A, C and D) or blue laser (in section B) on Yintang, Neiguan, Guanyuan or a special acupuncture regimen for stress disorders (in sections A, B, C and D, respectively). Significant decreases in heartrate after verum intervention at Yintang, Neiguan and Guanyuan were found. Improvements in state of health following teleacupuncture were also noted. Computer-based heartrate and heartrate variability analysis was demonstrated to be effective in evaluating the status of health during acupuncture. PMID:20869016
To observe the effect of age on the changes in heartrate variability (HRV) of adult amateur athletes after playing a soccer game, 20 male were divided into two groups: middle-aged (n = 10, 3555 years) and aged (n = 10, 5675 years). Before and after 2-hour soccer games, HRV and blood pressure were recorded. In both groups heartrate
Shuchun Yu; Takasumi Katoh; Hiroshi Makino; Soichiro Mimuno; Shigehito Sato
This paper assesses whether air pollution increases resting heartrates in 2,681 men and women aged 25-64 years who participated in the MONICA (monitoring of trends and determinants in cardiovascula r disease) Augsburg cohort. Increases in heartrate were observed during the air pollution episode in January 1985 compared with non-episode days adjusted for cardiovascular risk factors and meteorologic parameters.
Symptoms of anxiety suggest autonomic dysfunction and most of the psycho-tropic agents used to treat anxiety and affective disorders have strong autonomic effects. This article describes the utility and importance of analysis of heartrate and blood pressure time series to study cardiac autonomic function in psychiatric research. The variability of heartrate between 0.15 and 0.5 Hz is related
This experiment is concerned with the identification of physiological correlative evidence of test anxiety in a problem-solving situation. While low-anxious, medium-anxious, and high-anxious Ss attempted to solve anagrams, pulse-monitored heart-rate recordings were taken. The principal findings were that high-anxious Ss produced significantly larger increases in heartrate with the onset of the problem-solving task than low-anxious Ss. Also, large increases
Heartrate variability was studied in normal subjects age 1 month-24 years while awake and in active and quiet sleep using 24 h continuous recordings of the ECG. Variability was quantified by spectral analysis for the two frequency bands: low frequency (LF) 0.030.15 Hz, high frequency (HF) 0.150.6 Hz. Heartrate variability showed an age dependence, being in general an
A number of studies concerning heartrate variability and mental load arereviewedIt is concluded that in paced choice reaction tasks the number of reversal pointsin the cardiotachogram is the most sensitive measure of the load of the task.This measure was strongly correlated with respirationSpectral analysis of heartrate variability revealed the existence of a frequency component at about 0·10 Hz, a
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 heartrate 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
José C. Barbero-Álvarez; Maite Gómez López; Verónica Barbero Álvarez; Juan Grand; Carlo Castagna
Several studies have shown that heartrate fluctuations exhibit the ubiquitous 1/f behavior which is altered in desease. Furthermore, the analysis of electrocardiograms in natural time reveals that important malfunctions in the complex system of the human heart can be identified. Here, we present a simple evolution model in natural time that exhibits the 1/fa behavior with a close to unity. The results of this model are consistent with a progressive modification of heartrate variability in healthy children and adolescents. The model results in complexity measures that separate healthy dynamics from patients as well as from sudden cardiac death individuals.
In a study of 18 human subjects, we applied a new technique, estimation of the transfer function between instantaneous lung volume (ILV) and instantaneous heartrate (HR), to assess autonomic activity during motion sickness. Two control recordings of ILV and electrocardiogram (ECG) were made prior to the development of motion sickness. During the first, subjects were seated motionless, and during the second they were seated rotating sinusoidally about an earth vertical axis. Subjects then wore prism goggles that reverse the left-right visual field and performed manual tasks until they developed moderate motion sickness. Finally, ILV and ECG were recorded while subjects maintained a relatively constant level of sickness by intermittent eye closure during rotation with the goggles. Based on analyses of ILV to HR transfer functions from the three conditions, we were unable to demonstrate a change in autonomic control of heartrate due to rotation alone or due to motion sickness. These findings do not support the notion that moderate motion sickness is manifested as a generalized autonomic response.
Mullen, T. J.; Berger, R. D.; Oman, C. M.; Cohen, R. J.
Introduction: We aim to test our hypothesis that, during daily activity, though not as prominent as during HUT test, the patients may show different degree of intermittency in heartrates compared to healthy persons. METHOD AND RESULTS: Thirty patients with neurocardiogenic syncope who showed a positive HUT test and thirty healthy controls without history of syncope were included. Their twenty-four hour ambulatory electrocardiograms were digitized and RR interval (RRI) data of six-hour interval were analyzed. To quantify the intermittency (C1) behavior, The intermittency analysis was performed using Mexican hat wavelet. For the syncope group, the values of C1 were significantly higher at 6AM-6PM and lower at 6AM-midnight, respectively. However, the values were not different at midnight-6AM. The significant night-day circadian change shown in the control group was lost in C1. CONCLUSION: When compared to healthy control, the patients with neurocardiogenic syncope shows increased intermittency of heartrates in daytime during daily activity, and abnormal circadian rhythms of the index. These new findings may be useful for investigating the pathophysiology of neurocardiogenic syncope and early identification of the patients.
X-band Radar System for Detecting Heart and Respiration Rates Jee-Hoon Lee, Yun-Taek Im, and Seong and heartrates with the periodic movement of skin and muscle near the heart. Keywords-heartrate; X system to detect heart and respiration rates of human 10m away from antenna using a high gain array
BACKGROUND: Heartrate 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 heartrate 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 angiography for investigation of chest pain. SETTING: Regional cardiothoracic centre. METHODS: Sympathetic effector function at the sinus node was assessed by measuring the fall in cycle length for two minutes after injection of tyramine to the artery supplying the sinus node. Heartrate variability was measured from three-minute RR interval sequences at rest, during metronomic respiration, and before and after atropine. RESULTS: The logarithm of the low frequency component of heartrate variability during metronomic respiration was linearly related to the logarithm of the change in cycle length after injection of tyramine (R2 = 0.28, P = 0.007). Absolute units more accurately reflected sympathetic effector function than did normalised units or the ratio of low frequency to high frequency. Atropine did not affect high frequency heartrate variability in transplant recipients. CONCLUSIONS: The low frequency component of heartrate variability is directly related to sympathetic reinnervation to the sinus node. PMID:9227297
Lord, S. W.; Clayton, R. H.; Mitchell, L.; Dark, J. H.; Murray, A.; McComb, J. M.
Background Chagas disease patients with right bundle-branch block (RBBB) have diverse clinical presentation and prognosis, depending on left ventricular (LV) function. Autonomic disorder can be an early marker of heart involvement. The heartrate recovery (HRR) after exercise may identify autonomic dysfunction, with impact on therapeutic strategies. This study was designed to assess the HRR after symptom-limited exercise testing in asymptomatic Chagas disease patients with RBBB without ventricular dysfunction compared to patients with indeterminate form of Chagas disease and healthy controls. Methods One hundred and forty-nine subjects divided into 3 groups were included. A control group was comprised of healthy individuals; group 1 included patients in the indeterminate form of Chagas disease; and group 2 included patients with complete RBBB with or without left anterior hemiblock, and normal ventricular systolic function. A symptom-limited exercise test was performed and heartrate (HR) response to exercise was assessed. HRR was defined as the difference between HR at peak exercise and 1 min following test termination. Results There were no differences in heart-rate profile during exercise between healthy individuals and patients in indeterminate form, whereas patients with RBBB had more prevalence of chronotropic incompetence, lower exercise capacity and lower HRR compared with patients in indeterminate form and controls. A delayed decrease in the HR after exercise was found in 17 patients (15%), 9% in indeterminate form and 24% with RBBB, associated with older age, worse functional capacity, impaired chronotropic response, and ventricular arrhythmias during both exercise and recovery. By multivariable analysis, the independent predictors of a delayed decrease in the HRR were age (odds ratio [OR] 1.11; 95% confidence interval [CI] 1.03 to 1.21; p?=?0.010) and presence of RBBB (OR 3.97; 95% CI 1.05 to 15.01; p?=?0.042). Conclusions A small proportion (15%) of asymptomatic Chagas patients had attenuated HRR after exercise, being more prevalent in patients with RBBB compared with patients in indeterminate form and controls. PMID:24979699
de Alencar, Maria Clara Noman; Rocha, Manoel Otavio da Costa; Lima, Marcia Maria de Oliveira; Costa, Henrique Silveira; Sousa, Giovane Rodrigo; Carneiro, Renata de Carvalho Bicalho; Silva, Guilherme Canabrava Rodrigues; Brandao, Fernando Vieira; Kreuser, Lucas Jordan; Ribeiro, Antonio Luiz Pinho; Nunes, Maria Carmo Pereira
Under most circumstances heartrate (fH) is correlated with the rate of oxygen consumption (V?o2) and hence the rate of energy expenditure or metabolic rate (MR). For over 60years this simple principle has underpinned the use of heartrate to estimate metabolic rate in a range of animal species and to answer questions about their physiology, behaviour and ecology. The
Accurate heartrate measurement during work is required for many industrial hygiene and ergonomics situations. The purpose of this investigation was to determine the validity of heartrate measurements obtained by a simple, lightweight, commercially available wrist-worn heartrate 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 heartrates 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 heartrates compared with ECG recordings for the data set generated by an ECG simulator. The regression equation for the relationship between ECG versus HRM heartrate 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 heartrate responses during work.
Moore, A. D. Jr; Lee, S. M.; Greenisen, M. C.; Bishop, P.
The purpose of this study was to examine the running velocities and heartrates at fixed lactate concentrations of young soccer\\u000a players according to playing position and age. A total of 223 young male soccer players participated in this study. Each player\\u000a performed incremental exercise tests on a treadmill. Running velocities and heartrates at 2 mmol\\/L?1, 2.5 mmol\\/L?1, 3
An increase in muscular flexibility, as well as a significant beneficial effect on heartrate and heartrate variability (HRV), was observed in healthy male athletes after performing a standardized 15-minute stretching-program over a period of 28 days. We believe the HRV increase to be due, at least in part, to the improved vagal and\\/or diminished sympathetic control. Therefore, we
Objective: To determine the influence of lactic acidosis, the Bohr effect, and exercise induced hyperkalaemia on the occurrence of the heartrate deflection point (HRDP) in elite (professional) cyclists.Methods: Sixteen professional male road cyclists (mean (SD) age 26 (1) years) performed a ramp test on a cycle ergometer (workload increases of 5 W\\/12 s, averaging 25 W\\/min). Heartrate (HR),
A Luci?a; J Hoyos; A Santalla; M Pe?rez; A Carvajal; J L Chicharro
Summary Recent studies have demonstrated there is a definitive deflection in the heartrate response to incremental velocity work\\u000a that coincides with the anaerobic threshold. These studies were conducted with elite athletes who performed the specific activities\\u000a in which they were trained. The purpose of this study was to determine if the same relationship in heartrate and ventilatory\\u000a response to
K. T. Francis; P. R. McClatchey; J. R. Sumsion; D. E. Hansen
This thesis examines two challenging problems in chaos analysis: distinguishing deterministic chaos and stochastic (noise-induced) chaos, and applying chaotic heartrate variability (HRV) analysis to the prognosis of ...
The main goal of the thesis is to document developmental changes in heartrate responsitivity and attention during the middle childhood period. The thesis consists of two parts--a methodological and an empirical part. The methodological part concerns the ...
We present systematic evidence for the origins of 1/f -type temporal scaling in human heartrate. The heartrate 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 in the Hurst exponent H towards random-walk scaling 1/f2 and a similar breakdown is observed with relative SNS suppression by primary autonomic failure. These results suggest that 1/f scaling in heartrate requires the intricate balance between the antagonistic activity of PNS and SNS.
1 Heart Physiology Worksheet Table 1. Pulse Rate Data Individual Lying down Sitting Standing During #12;3 Graph 1. Bar graph of class averages for pulse rate data. 0 20 40 60 80 100 120 140 160 180 200 6 Min Exercise MEASUREMENT #12;5 Questions: 1. Pulse Rate: Based on examination of your bar graph a
Background: Work stress indicated by effortreward imbalance is hypothesized to cause autonomic arousal, which, if prolonged\\u000a or frequent, could contribute to cardiovascular pathology. However, only limited empirical evidence on this mechanism is available.\\u000a Purpose: This study examined associations between effort-reward imbalance, heartrate (HR), and heartrate variability (HRV).\\u000a Method: The participants were 457 women and 406 men (mean age
Mirka Hintsanen; Marko Elovainio; Sampsa Puttonen; Mika Kivimäki; Tuomas Koskinen; Olli T. Raitakari; Liisa Keltikangas-Järvinen
Molt is an important life-history stage in avian species, but little is known about the effects of chronic stress during this period. Three weeks after the onset of molt, captive European starlings (Sturnus vulgaris) were exposed to 18 days of chronic stress, induced with four 30-minute randomized stressors presented daily. Birds showed no chronic-stress-induced changes in heartrate or heartrate
Sophia Kostelanetz; Molly J. Dickens; L. Michael Romero
Flight Modes in Migrating European Bee-Eaters: HeartRate May Indicate Low Metabolic Rate during the relationship between heart beat frequency and metabolic rate (by indirect calorimetry) in the laboratory. Heart, Wikelski M, McCue MD, Pinshow B, Nathan R (2010) Flight Modes in Migrating European Bee-Eaters: HeartRate
Heartrate variability (HRV) has long been used in risk stratification for sudden cardiac death and diabetic autonomic neuropathy. In recent years, both time and frequency domain indices of HRV also gained increasing interest in sports and training sciences. In these fields, HRV is currently used for the noninvasive assessment of autonomic changes associated with short-term and long-term endurance exercise training in both leisure sports activity and high-performance training. Furthermore, HRV is being investigated as a diagnostic marker of overreaching and overtraining.A large body of evidence shows that, in healthy subjects and cardiovascular patients of all ages (up to an age of 70 years), regular aerobic training usually results in a significant improvement of overall as well as instantaneous HRV. These changes, which are accompanied by significant reductions in heartrates both at rest and during submaximal exercise, reflect an increase in autonomic efferent activity and a shift in favor of enhanced vagal modulation of the cardiac rhythm. Regular aerobic training of moderate volume and intensity over a minimum period of 3 months seems to be necessary to ensure these effects, which might be associated with a prognostic benefit regarding overall mortality.At present, available data does not allow for final conclusions with respect to the usefulness of traditional HRV indices in assessing an individual's exercise performance and monitoring training load. The discrepant results published so far are due to several factors including insufficient study size and design, and different HRV methods. Large-sized and prospectively designed studies are necessary for clarification. It also remains to be seen, whether the traditional HRV indices prove useful in the diagnosis of overreaching and overtraining. Preliminary results, though promising, need to be confirmed in larger cohorts.A basic problem in HRV analysis is nonstationarity of the heartrate signal, which holds particularly true for exercise conditions. Whether, in these conditions, more robust nonlinear HRV methods offer a benefit has to be established in further work. PMID:17036185
Hottenrott, Kuno; Hoos, Olaf; Esperer, Hans Dieter
Statistical, spectral, multi-resolution and non-linear methods were applied to heartrate variability (HRV) series linked with classification schemes for the prognosis of cardiovascular risk. A total of 90 HRV records were analyzed: 45 from healthy subjects and 45 from cardiovascular risk patients. A total of 52 features from all the analysis methods were evaluated using standard two-sample Kolmogorov-Smirnov test (KS-test). The results of the statistical procedure provided input to multi-layer perceptron (MLP) neural networks, radial basis function (RBF) neural networks and support vector machines (SVM) for data classification. These schemes showed high performances with both training and test sets and many combinations of features (with a maximum accuracy of 96.67%). Additionally, there was a strong consideration for breathing frequency as a relevant feature in the HRV analysis. PMID:21386966
Ramirez-Villegas, Juan F.; Lam-Espinosa, Eric; Ramirez-Moreno, David F.; Calvo-Echeverry, Paulo C.; Agredo-Rodriguez, Wilfredo
The arguments are given that local exponents obtained in multifractal analysis by two methods: wavelet transform modulus maxima (WTMM) and multifractal detrended fluctuation analysis (MDFA) allow to separate statistically hearts of healthy people and subjects suffering from reduced left ventricle systolic function (NYHA I-III class). Proposed indices of fractality suggest that a signal of human heartrate is a mixture of two processes: monofractal and multifractal ones.
Makowiec, Danuta; Ga?a?ka, Rafa?; Dudkowska, Aleksandra; Rynkiewicz, Andrzej; Zwierz, Marcin
A body of evidence indicates that subjects with tachycardia are more likely to develop hypertension (13) and atherosclerosis in future years (46). However, the connection between heartrate and cardiovascular risk has long been neglected on the grounds that tachycardia\\u000a is often associated with the traditional risk factors for atherosclerosis, such as hypertension or metabolic abnormalities\\u000a (7). A high heart
Fetal heartrate 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 heartrate 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 heartrate. 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 heartrate 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 heartrate 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 heartrate 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.
The study of heartrate 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
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. Heartrate 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.
Heartrate, a hemodynamic parameter, is an important determinant of arterial wall stiffness. However, information on the relationship of heartrate to arterial wall thickness is inconsistent. This study examined the influence of heartrate on arterial stiffness and thickness in Black and White young adults. The study cohort consisted of 255 Black and 659 White adults age 25 to
Wei Chen; Sathanur R. Srinivasan; Gerald S. Berenson
In this paper, various methods of heart beat variability assessment from speech analysis have been presented. Heartrate variability (HRV) is a physiological phenomenon where the time interval between heart beats varies. It is measured by the variation in the beat-to-beat interval. The present work deals with the HRV detection from speech parameters. RR-cycle detects one heart beat. Continuous monitoring of electrocardiograph for a span of time can provide HRV. More than 250 samples of normal informants as well as heart patients with enlarged heart have been collected during the four years of research work. The regular ECG and speech samples of the patient have been collected and analyzed. Further they had compared with the parameters of a normal healthy informant. Speech samples were collected through a microphone and subjected to be digitized. The required speech segmental have been extracted and analyzed through a DSP tool, PRAAT. ECG sample has been recorded through an ECG machine. A technique of HRV detection from speech analysis has been presented in this paper. The HRV detection from speech can be a very helpful tool in monitoring the functioning of human heart. PMID:25236132
Deshpande, Nivedita; Thakur, Kavita; Zadgaonkar, Arun S
Background Musical performance is a skilled activity performed under intense pressure, thus is often a profound source of anxiety. In other contexts, anxiety and its concomitant symptoms of sympathetic nervous system arousal have been successfully ameliorated with HRV biofeedback (HRV BF), a technique involving slow breathing which augments autonomic and emotional regulatory capacity. Objective: This randomised-controlled study explored the impact of a single 30-minute session of HRV BF on anxiety in response to a highly stressful music performance. Methods A total of 46 trained musicians participated in this study and were randomly allocated to a slow breathing with or without biofeedback or no-treatment control group. A 3 Group×2 Time mixed experimental design was employed to compare the effect of group before and after intervention on performance anxiety (STAI-S) and frequency domain measures of HRV. Results Slow breathing groups (n?=?30) showed significantly greater improvements in high frequency (HF) and LF/HF ratio measures of HRV relative to control (n?=?15) during 5 minute recordings of performance anticipation following the intervention (effect size: ?2?=?0.122 and ?2?=?0.116, respectively). The addition of biofeedback to a slow breathing protocol did not produce differential results. While intervention groups did not exhibit an overall reduction in self-reported anxiety, participants with high baseline anxiety who received the intervention (n?=?15) displayed greater reductions in self-reported state anxiety relative to those in the control condition (n?=?7) (r?=?0.379). Conclusions These findings indicate that a single session of slow breathing, regardless of biofeedback, is sufficient for controlling physiological arousal in anticipation of psychosocial stress associated with music performance and that slow breathing is particularly helpful for musicians with high levels of anxiety. Future research is needed to further examine the effects of HRV BF as a low-cost, non-pharmacological treatment for music performance anxiety. PMID:23056361
Wells, Ruth; Outhred, Tim; Heathers, James A. J.; Quintana, Daniel S.; Kemp, Andrew H.
BackgroundThe predictive value of heartrate variability (HRV) in chronic heart failure (CHF) has never been tested in a comprehensive multivariate model using short-term laboratory recordings designed to avoid the confounding effects of respiration and behavioral factors. Methods and ResultsA multivariate survival model for the identification of sudden (presumably arrhythmic) death was developed with data from 202 consecutive patients referred
Maria Teresa La Rovere; Gian Domenico Pinna; Roberto Maestri; Andrea Mortara; Soccorso Capomolla; Oreste Febo; Roberto Ferrari; Mariella Franchini; Marco Gnemmi; Cristina Opasich; Pier Giorgio Riccardi; Egidio Traversi; Franco Cobelli
The diagnostic performance of two pattern classification methods to detect hypertension was evaluated in a population of 29 mildly hypertensive and 20 normal subjects. The heartrate variability (HRV) signal of each subject was recorded during rest and isometric handgrip exercise. Feature vectors composed of up to 6 features from both the time and frequency domain representation of the HRV signal were constructed and applied to a Bayes' likelihood classifier and a voting k-nearest neighbours classifier. Each subject was classified as hypertensive or normal, and the classification compared to the clinical diagnosis for each subject. The diagnostic performance of each classifier/feature vector combination was evaluated using the leave-one-out method. The best performance of 90% correct classifications was achieved using a nearest neighbour classifier, a Euclidean distance metric and 3 features. The Bayes' classifier achieved a best performance of 84% correct classification. The work shows promise for the detection of the autonomic disturbance which precedes and accompanies the hypertensive state. PMID:9503692
The first six Kramers-Moyal coefficients were extracted from human heartrate variability recordings. The method requires the determination of the Markov time and of the proper conditional probability densities. We analyzed heartrate data recorded in a group of ten young, healthy subjects. We obtained non-negligible higher order Kramers-Moyal (K-M) terms in 6 h nighttime parts of the 24 h recordings. This indicates that the data is a non-Gaussian process and probably a correlated signal. The analysis yielded important new insights into the character and distribution of the stochastic processes measured in healthy group. In the night hours, the dominant oscillation in the heartrate is the so called respiratory sinus arrhythmia (RSA) -- a physiological phenomenon in which respiration acts as a drive for the heartrate. Certain kinds of pathology may disrupt RSA. We compared nighttime recordings of the healthy group with those recorded in six patients with hypertrophic cardiomyopathy (HCM). HCM is generally a pathology of heart cells but abnormalities in autonomic regulation are also observed. Using the higher order Kramers-Moyal coefficients, we analyzed the skewness and kurtosis in the nighttime recordings for the normal subjects.
This study aimed to describe the work-rate profiles of referees during soccer matches and record heart-rate responses during these games. Using video-recordings 14 referees were observed and their heartrates during the games were monitored by short-range radio telemetry. These included 11 football league matches. The exercise intensity was largely submaximal with a change in activity every 6 s. The mean distance covered during the game was 9.44 km; a significant fall in work rate was noted in the second half (P < 0.05). The mean heartrate of 165 beats min-1 did not vary between first and second halves. The work rate and heartrate varied more between individuals than with the importance of the match, but this variation was small. It was considered that refereeing top level soccer places high physiological demands on the official. This has implications for training and fitness assessment. PMID:8242278
Catterall, C; Reilly, T; Atkinson, G; Coldwells, A
We report extremely prominent heartrate oscillations associated with slow breathing during specific traditional forms of Chinese Chi and Kundalini Yoga meditation techniques in healthy young adults. We applied both spectral analysis and a novel analytic technique based on the Hilbert transform to quantify these heartrate dynamics. The amplitude of these oscillations during meditation was significantly greater than in the pre-meditation control state and also in three non-meditation control groups: i) elite athletes during sleep, ii) healthy young adults during metronomic breathing, and iii) healthy young adults during spontaneous nocturnal breathing. This finding, along with the marked variability of the beat-to-beat heartrate dynamics during such profound meditative states, challenges the notion of meditation as only an autonomically quiescent state. PMID:10454297
Peng, C K; Mietus, J E; Liu, Y; Khalsa, G; Douglas, P S; Benson, H; Goldberger, A L
BackgroundPatients with chronic heart failure (CHF) have a continuing high mortality. Autonomic dysfunction may play an important role in the pathophysiology of cardiac death in CHF. UK-HEART examined the value of heartrate variability (HRV) measures as independent predictors of death in CHF. Methods and ResultsIn a prospective study powered for mortality, we recruited 433 outpatients 62 69.6 years old
James Nolan; Phillip D. Batin; Richard Andrews; Steven J. Lindsay; Paul Brooksby; Michael Mullen; Wazir Baig; Andrew D. Flapan; Alan Cowley; Robin J. Prescott; James M. M. Neilson; Keith A. A. Fox
The authors attempted to reduplicate the Lacey phenomenon of heartrate acceleration during the performance of an interiorized mental task and its maintenance in time. For this purpose they resorted to the pavlovian conditioning paradigm. The heart-rate response was obtained repetitively thanks to a change of structure and\\/ or content of the task and a conditioned response was elicited in
The effect of spinal anesthesia on fetal heartrate is due to maternal hypotension and subsequent fetal hypoxia. Maternal hypotension of 80 mm of mercury for five minutes almost always results in hypoxic fetal bradycardia. This bradycardia is gradual in onset, and may be preceded by a short period of fetal tachycardia. There is a lag in the return of fetal heartrate to normal after maternal blood pressure has normalized. Similar bradycardia has been observed in maternal syncope unassociated with anesthesia. Maternal hypotension should be prevented, and if it occurs should be corrected early. Administration of a vasopressor drug is the treatment of choice, with oxygen and fluids as indicated. PMID:14084683
We describe a simple but robust algorithm for estimating the heartrate pulse from video sequences containing human skin in real time. Based on a model of light interaction with human skin, we define the change of blood concentration due to arterial pulsation as a pixel quotient in log space, and successfully use the derived signal for computing the pulse heartrate. Various experiments with different cameras, different illumination condition, and different skin locations were conducted to demonstrate the effectiveness and robustness of the proposed algorithm. Examples computed with normal illumination show the algorithm is comparable with pulse oximeter devices both in accuracy and sensitivity. PMID:24761294
We use measured heartrate information (RR intervals) to develop a one-dimensional nonlinear map that describes short term deterministic behavior in the data. Our study suggests that there is a stochastic parameter with persistence which causes the heartrate and rhythm system to wander about a bifurcation point. We propose a modified circle map with a jump process noise term as a model which can qualitatively capture such this behavior of low dimensional transient determinism with occasional (stochastically defined) jumps from one deterministic system to another within a one parameter family of deterministic systems. PMID:23906210
Exercise video games combine entertainment and physical movement in an effort to encourage people to be more physically active. Multiplayer exercise games take advantage of the motivating aspects of group activity by allowing people to exercise together. However, people of significantly different fitness levels can have a hard time playing together, as large differences in performance can be demotivating. To
Tadeusz Stach; T. C. Nicholas Graham; Jeffrey Yim; Ryan E. Rhodes
Background Accurate measurement of free-living energy expenditure is vital to understanding changes in energy metabolism with aging. The efficacy of heartrate as a surrogate for energy expenditure is rooted in the assumption of a linear function between heartrate and energy expenditure, but its validity and reliability in older adults remains unclear. Objective To assess the validity and reliability of the linear function between heartrate and energy expenditure in older adults using different levels of calibration. Design Heartrate and energy expenditure were assessed across five levels of exertion in 290 adults participating in the Baltimore Longitudinal Study of Aging. Correlation and random effects regression analyses assessed the linearity of the relationship between heartrate and energy expenditure and cross-validation models assessed predictive performance. Results Heartrate and energy expenditure were highly correlated (r?=?0.98) and linear regardless of age or sex. Intra-person variability was low but inter-person variability was high, with substantial heterogeneity of the random intercept (s.d.?=?0.372) despite similar slopes. Cross-validation models indicated individual calibration data substantially improves accuracy predictions of energy expenditure from heartrate, reducing the potential for considerable measurement bias. Although using five calibration measures provided the greatest reduction in the standard deviation of prediction errors (1.08 kcals/min), substantial improvement was also noted with two (0.75 kcals/min). Conclusion These findings indicate standard regression equations may be used to make population-level inferences when estimating energy expenditure from heartrate in older adults but caution should be exercised when making inferences at the individual level without proper calibration. PMID:24787146
Schrack, Jennifer A.; Zipunnikov, Vadim; Goldsmith, Jeff; Bandeen-Roche, Karen; Crainiceanu, Ciprian M.; Ferrucci, Luigi
We report the first measurements of heartrate (f(H)) and the rate of oxygen consumption (V(O(2))) during flights from a species of bird larger than 500 g. V(O(2))was obtained from nine forward flapping flights of 8.9 min mean duration at a mean speed of 13.2 m s(-1) performed by three barnacle geese of mean mass 1.68 kg. Mean V(O(2))was 332 ml min(-1)or 201 ml min(-1) kg(-1). Sixteen flights were obtained from two of these birds equipped with heartrate data loggers, both when they were wearing a V(O(2)) mask and when they were not. During flights with the mask (mean duration 7.4 min), mean f(H) was 472 beats per min and during flights without the mask (mean duration 8.0 min) it was 391 beats per min. Heartrate was also measured in another goose flying without a respiratory mask and mean f(H) for all the three birds (mean mass 1.7 kg) flying without a mask for an average of 7.9 min at 13 m s(-1) was 378 beats per min. Resting f(H) for these three birds was 79 beats per min. The values of f(H) during flight are greater than those obtained from the same species during their autumn migration from Spitsbergen to southern Scotland. The possible reasons for this are discussed. PMID:10964032
Butler, P J; Woakes, A J; Bevan, R M; Stephenson, R
Introduction to Controversial Topics in Nonlinear Science: Is the Normal HeartRate Chaotic? Leon. The first of these deals with the dynamical characterization of human heartrate variability. We asked authors to respond to the following questions: Is the normal heartrate chaotic? If the normal heartrate
Differential heartrates during heating and cooling (heartrate hysteresis) are an important thermoregulatory mechanism in ectothermic reptiles. We speculate that heartrate hysteresis has evolved alongside vascularisation, and to determine whether this phenomenon occurs in a lineage with vascularised circulatory systems that is phylogenetically distant from reptiles, we measured the response of heartrate to convective heat transfer in
Jacqueline E. Goudkamp; Frank Seebacher; Mark Ahern; Craig E. Franklin
Obtained simultaneous measures of heartrate and approach behavior in the feared situation during treatment of 9 15-56 yr. Old phobic ss. In some cases heartrate increased as phobic avoidance behavior decreased. In other cases there was a parallel decline, a decline in phobic behavior without any change in heartrate, or a decreased heartrate only after phobic
Harold Leitenberg; Stewart Agras; Robert Butz; John Wincze
This study identified the highest heartrates attained on a ropes course for a corporate population; examined relationships between highest heartrate and other physical measures (basal heartrate, blood pressure, height, weight, body girths, cholesterol, maximum number of pushups, and heartrate after brisk walk); and developed an equation for
To compare image quality of coronary CT angiography in step-and-shoot mode at the diastolic phase at low heartrates (<70 bpm) and systolic phase at high heartrates (?70 bpm). We prospectively included 96 consecutive patients then excluded 5 patients with arrhythmia. Coronary CT-angiography was performed using a dual-source 128-slice CT machine, at the diastolic phase in the 55 patients with heartrates <70 bpm (group D) and at the systolic phase in the 36 patients with heartrates ?70 (group S). Image quality was scored on a 5 point-scale (1, not interpretable; 2, insufficient for diagnosis; 3, fair, sufficient for diagnosis; 4, good; 5, excellent). In addition, we compared the number of stair-step artifacts in the two groups. Mean image quality score was 4 (0.78) in group D and 4.1 (0.34) in group S (NS), with an unequal distribution (p = 0.01). Step artifacts were seen in 44 % of group D and 18 % of group S patients (p = 0.02). In 3 group D patients and no group S patients, the image score was <3 due to artifacts, requiring repeat CT-angiography. When performing dual-source 128-slice CT-angiography, step-and-shoot acquisition provides comparable mean image quality in systole, with less variability and fewer stair-step artifacts, compared to diastole. This method may be feasible at any heartrate in most patients in sinus rhythm, allowing low-dose prospective acquisition without beta-blocker premedication. PMID:22918571
This study investigated alterations in heartrate variability (HRV) and cognitive performance before and after physical effort, for 30 high-level track and field athletes (23 males and 7 females). Interbeat intervals were assessed at the baseline and during each task of a CogState cognitive battery (simple reaction time, choice reaction time, working memory, short-term memory and sustained attention). Time and frequency domain measures of HRV were compared between conditions and between tasks. The results indicated differences in HRV between executive and non-executive tasks. There was a significant increase in sympathetic-modulation-related indices after physical effort. The differences between executive and non-executive tasks were the same in post-test. Correlations were found between HRV and cognitive performance, which differed by speed and accuracy. We conclude that HRV is related to cognitive demand and that the correlation between HRV and cognitive performance seems to be stronger after physical exercise. The results raise questions about the psychophysiological meaning of different HRV signals and this has implications for future research about the relationship between HRV and cognition. PMID:19632295
Luft, Caroline Di Bernardi; Takase, Emílio; Darby, David
We studied 54 patients with hypoxemic chronic obstructive pulmonary disease (COPD). The Mini Mental State Examination and the Mental Deterioration Battery were used for neuropsychological assessment. Heartrate variability (HRV) was assessed based on 24-h Holter ECG recording. Mann-Whitney test was used to compare HRV parameters of patients performing normally or abnormally on individual neuropsychological tasks. Spearman's rho was used to investigate the correlations between HRV parameters and neuropsychological scores, indexes of health status or COPD severity. Patients with defective performance at copying drawings with landmarks (CDL) test (N = 23) had lower very low frequency (VLF) power with respect to patients with normal performance (N = 31) (24 h: median 213; interquartile range 120-282 vs. 309; 188-431 ms2, p = 0.043; daytime: 202; 111-292 vs. 342; 194-397 ms2, p = 0.039). The CDL score correlated with the VLF power (24 h: rho = 0.27, p = 0.049; daytime: rho = 0.30, p = 0.028), and the normalized low frequency/high frequency (LF/HF) ratio (24 h: rho = 0.27, p = 0.05; daytime: rho = 0.33, p = 0.015). Sympathetic modulation decreased for increasing severity of COPD. In conclusion, drawing impairment correlates with depressed sympathetic modulation in patients with COPD, and both might be indexes of COPD severity. PMID:19261365
Diving behaviour and heartrate were monitored in tufted ducks diving under circumstances which simulated various environmental conditions such as feeding under ice in winter. When distance to food was increased on a covered outdoor pond, dive duration increased proportionately, but it was calculated that time available for feeding was reduced during the longer-distance 'extended' dives. There was a gradual reduction in heartrate to 77.3 +/- 13.8 beats min-1, which is significantly lower than the resting value of 121.1 +/- 14.1 beats min-1, during the course of extended dives, suggesting that the ducks could gradually switch over to a 'classical' oxygen-conserving response during these prolonged voluntary dives. The duration of the pre-dive preparatory period was positively correlated with dive distance. When the ducks were briefly unable to resurface during an otherwise normal feeding dive in an indoor tank, a situation which may occur if they become disoriented under ice, there was an immediate switch to a full bradycardia. Reduction in heartrate during these 'enclosed' dives occurred only when the ducks were apparently aware of the situation and the rate of onset of bradycardia was very similar to that previously observed during involuntary submersion of tufted ducks. Minimum heartrate was the same at 46 beats min-1 after 15 s of enclosed dives and after 30 s of involuntary submersions, despite the differences in levels of activity in the two situations. PMID:3805996
We studied the time course and change in heartrate during respiratory pauses in puppies (3-4 wk) and young adult dogs. We measured ventilation and ventilatory pattern using barometric plethysmography and recorded the respiratory rate (RR) interval using a pre-processor with an accuracy of 0.2 ms. During tidal breathing, the fluctuations in RR interval were an order of magnitude smaller in the puppy than in the dog. During respiratory pauses in dogs, the RR interval increased sharply, stabilized around the level of expiration of previous breaths, and dropped immediately with the subsequent inspiratory effort. The time course of the change in heartrate was different in the puppy: there was a gradual increase in the RR interval during the entire course of the pause and the maximum RR interval reached was substantially higher than during expiration of previous breaths. Our results suggest that 1) the change in heartrate at the outset of respiratory pauses is too fast to be related to blood gas changes in both puppies and dogs and 2) the mechanisms responsible for the vagal gating of heartrate during tidal breathing and during respiratory pauses are not well developed in early life in the puppy. PMID:3658551
These rating scales are intended for evaluation of student pilot performance. Each student is evaluated individually on the basis of video recordings of the student in flight. Ten point rating lines are used for the ten criterion performance elements of each of three maneuvers, (1) Final Turn to Landing, (2) Lazy Eight, and (3) Vertical S "A".
Measurement of mental workload has been widely used for evaluation of aircraft design, mission analysis and assessment of pilot performance during flight operations. Heartrate is the psychophysiological measure that has been most frequently used for this purpose. The risk of interference with flight safety and pilot performance, as well as the generally constrained access to flights, make it difficult
Homoclinic trajectories of the interbeat intervals between contractions of ventricles of the human heart are identified. The interbeat intervals are extracted from 24-h Holter ECG recordings. Three such recordings are discussed in detail. Mappings of the measured consecutive interbeat intervals are constructed. In the second and in some cases in the fourth iterate of the map of interbeat intervals homoclinic trajectories associated with a hyperbolic saddle are found. The homoclinic trajectories are often persistent for many interbeat intervals, sometimes spanning many thousands of heartbeats. Several features typical for homoclinic trajectories found in other systems were identified, including a signature of the gluing bifurcation. The homoclinic trajectories are present both in recordings of heartrate variability obtained from patients with an increased number of arrhythmias and in cases in which the sinus rhythm is dominant. The results presented are a strong indication of the importance of deterministic nonlinear instabilities in human heartrate variability.
The modulation of the autonomic nervous system (ANS) under physiological and pathophysiological conditions is in focus of recent research. Many patients with cardio- and cerebrovascular diseases display features of sympathovagal dysregulation. Measuring specific ANS parameters could improve risk stratification. Thus, the early diagnosis of ANS dysfunction in these patients poses a great challenge with high prognostic relevance. The most relevant methods and measures of HeartRate Variability (HRV) analysis and HRV monitoring will be described in detail in this chapter. The grown importance of these easily obtainable heartrate patterns in stratifying the risk of patients with myocardial infarction and heart failure as well as ischemic stroke will be demonstrated based on recent clinical studies. In order to perspectively improve clinical management of these patients further large scale clinical investigations on the role of ANS dysfunction will be useful. PMID:21258571
Background Diabetes may confer an increased risk for the cardiovascular health effects of particulate air pollution, but few human clinical studies of air pollution have included people with diabetes. Ultrafine particles (UFP, ?100 nm in diameter) have been hypothesized to be an important component of particulate air pollution with regard to cardiovascular health effects. Methods 17 never-smoker subjects 3060 years of age, with stable type 2 diabetes but otherwise healthy, inhaled either filtered air (010 particles/cm3) or elemental carbon UFP (~107 particles/cm3, ~50 ug/m3, count median diameter 32 nm) by mouthpiece, for 2 hours at rest, in a double-blind, randomized, crossover study design. A digital 12-lead electrocardiogram (ECG) was recorded continuously for 48 hours, beginning 1 hour prior to exposure. Results Analysis of 5-minute segments of the ECG during quiet rest showed reduced high-frequency heartrate variability with UFP relative to air exposure (p?=?0.014), paralleled by non-significant reductions in time-domain heartrate variability parameters. In the analysis of longer durations of the ECG, we found that UFP exposure increased the heartrate relative to air exposure. During the 21- to 45-hour interval after exposure, the average heartrate increased approximately 8 beats per minute with UFP, compared to 5 beats per minute with air (p?=?0.045). There were no UFP effects on cardiac rhythm or repolarization. Conclusions Inhalation of elemental carbon ultrafine particles alters heartrate and heartrate variability in people with type 2 diabetes. Our findings suggest that effects may occur and persist hours after a single 2-hour exposure. PMID:25028096
Study Objectives: Nocturnal cardiovascular events are more frequent at the beginning and end of the night. It was proposed that this pattern reflects the nocturnal distribution of sleep and sleep stages. Using heartrate variability (HRV), we recently showed an interaction between the circadian system and vigilance states on the regulation of cardiac rhythmicity. Here, we further investigate this interaction in order to clarify the specific effects of sleep stages on the regulation of the heart. Design: Participants underwent a 72-h ultradian sleep-wake cycle procedure in time isolation consisting of alternating 60-min wake episodes in dim light and 60-min nap opportunities in total darkness. Setting: Time isolation suite. Patients or participants: Fifteen healthy young participants; two were subsequently excluded. Interventions: N/A. Measurements and Results: The current study revealed that sleep onset and progression to deeper sleep stages was associated with a shift toward greater parasympathetic modulation, whereas rapid eye movement (REM) sleep was associated with a shift toward greater sympathetic modulation. We found a circadian rhythm of heartrate (HR) and high-frequency power during wakefulness and all non-REM sleep stages. A significant circadian rhythm of HR and sympathovagal balance of the heart was also observed during REM sleep. During slow wave sleep, maximal parasympathetic modulation was observed at ?02:00, whereas during REM sleep, maximal sympathetic modulation occurred in the early morning. Conclusion: The circadian and sleep stage-specific effects on heartrate variability are clinically relevant and contribute to the understanding of the degree of cardiovascular vulnerability during sleep. Citation: Boudreau P; Yeh WH; Dumont GA; Boivin DB. Circadian variation of heartrate variability across sleep stages. SLEEP 2013;36(12):1919-1928. PMID:24293767
Boudreau, Philippe; Yeh, Wei-Hsien; Dumont, Guy A.; Boivin, Diane B.
A new measure of acceleration of heartrate: dependence on age and comparison with time domain conventional heartrate variability measures Giuseppe GermanÃ², M.D., Gianfranco Piccirillo, M.D., *Camillo The heartrate variability (HRV) results from a variety of factors that are not purely stochastic
Objective The aim of this study was to evaluate heartrate variability (HRV) and heartrate recovery (HRR) in otherwise healthy ankylosing\\u000a spondlitis (AS) patients and control subjects.\\u000a \\u000a \\u000a \\u000a \\u000a Methods A total of 28 patients with AS and 30 volunteers matched for age and sex were enrolled. All subjects underwent HRV analysis,\\u000a exercise testing (ET), and transthoracic echocardiography. HRR indices were calculated by
Ergun Baris Kaya; Sercan Okutucu; Hakan Aksoy; Ugur Nadir Karakulak; Erol Tulumen; Oya Ozdemir; Fatma Inanici; Kudret Aytemir; Giray Kabakci; Lale Tokgozoglu; Hilmi Ozkutlu; Ali Oto
Objective: The purpose of this study was to investigate the relationship between depression and heartrate variability in cardiac patients. Methods: Heartrate variability was measured during 24-hour ambulatory electrocardiographic (ECG) monitoring in 40 medically stable out-patients with documented coronary heart disease meeting current diagnostic criteria for major depression, and 32 nondepressed, but otherwise comparable, patients. Patients discontinued ?-blockers and
Phyllis K Stein; Robert M Carney; Kenneth E Freedland; Judith A Skala; Allan S Jaffe; Robert E Kleiger; Jeffrey N Rottman
We studied 54 patients with hypoxemic chronic obstructive pulmonary disease (COPD). The Mini Mental State Examination and the Mental Deterioration Battery were used for neuropsychological assessment. Heartrate variability (HRV) was assessed based on 24-h Holter ECG recording. Mann-Whitney test was used to compare HRV parameters of patients
SUMMARY Diving behaviour and heartrate were monitored in tufted ducks diving under circumstances which simulated various environmental conditions such as feeding under ice in winter. When distance to food was increased on a covered outdoor pond, dive duration increased proportionately, but it was calculated that time available for feeding was reduced during the longer-distance 'extended' dives. There was a
A recent report hypothesized that episodes of space motion sickness (SMS) were reliably associated with low frequency oscillations (less than 0.03 to less than 0.01 Hz) in heartrate variability. This paper archives a large data set for review of investigators in this field which may facilitate the evaluation of this hypothesis. Continuous recording of Electro-cardiography (ECG) and other measures were made for 6 to 12 hours per day (waking hours) of six Shuttle crewmembers for the first 3 mission days of two separate Shuttle flights. Spectral analyses of heartrate variability during approximately 200 hours of inflight is presented. In addition, nearly 200 hours of data collected on these same individuals during ground tests prior to the mission are presented. The Purpose of this Publication is to document the incidence of low frequency oscillations of heartrate in 4 people exposed to microgravity over a period of five days. In addition, this report contains spectral analyses of heartrate data collected on these same individuals during ground-based mission simulations. By archiving these data in this manner, it is our intention to make this information available to other investigators interested in studying this phenomena.
Conditions producing stress are present in all colleges and universities. In this paper we report on an investigation utilizing heartrate as an indicator of stress in students when participating in activities encountered in a college classroom or laboratory. The activities included presenting an oral report, taking an exam, and participating in a
Cardiotocography is the most diffused prenatal diagnostic technique in clinical routine. The simultaneous recording of foetal heartrate (FHR) and uterine contractions (UC) provides useful information about foetal well-being during pregnancy and labour. However, foetal electronic monitoring interpretation still lacks reproducibility and objectivity. New methods of interpretation and new parameters can further support physicians decisions. Besides common time-domain analysis, study
Maria Romano; Paolo Bifulco; Mario Cesarelli; Mario Sansone; Marcello Bracale
Heartrate variability (HRV) and complexity (HRC) were calculated at rest and during an isometric hand grip test (IHGT) within 48-hours (48 h) and two weeks (Week Two) of a concussion in athletes (CG) and control subjects. No differences were present at rest or in HRV during IGHT. HRC was significantly lower in the CG compared to controls at 48 h during
Michael F. La Fountaine; Kevin S. Heffernan; James D. Gossett; William A. Bauman; Ronald E. De Meersman
National health and fitness data suggests that a significant percentage of children are not on a pathway to leading healthy, physically active lifestyles. Many children are leading sedentary lifestyles due to a lack of opportunity, success, or self-motivation in physical activity. Programs that highlight the use of heartrate monitors offer a
To obtain optimal training effects and avoid overtraining, it is necessary to monitor the intensity of training. In cycling, speed is not an accurate indicator of exercise intensity, and therefore alternatives have to be found to monitor exercise intensity during training and competition. Power output may be the most direct indicator, but heartrate is easier to monitor and measure.
Various anxiety states have been linked with disorders of the autonomic nervous system. These autonomic disorders may be revealed by analysis of physiological time series such as the heartrate interbeat interval series. The present paper reports a general model of biological system functioning and related assessment indices based on recent nonlinear dynamical systems approaches. In particular, two experimental studies
The present experiment was undertaken to assess the ways in which benzodiazepine administration alters heartrate responding during Pavlovian aversive conditioning in the rabbit. Each of three benzodiazepine compounds (chlordiazepoxide, flurazepam, diazepam) reliably attenuated the magnitude of the conditioned bradycardia response as compared to vehicle controls. Lower doses of two of these compounds significantly potentiated the conditioned bradycardia response. Benzodiazepine
HeartRate Variability (HRV) analysis has gained much importance in recent years, as a technique to explore the activity of autonomic nervous system (ANS), and an important early marker for identifying different pathological conditions. Epilepsy is a disease which progressively involves cardiac autonomic activity. Our studies indicate that time domain, frequency domain and some nonlinear measures of HRV would be
Soroor Behbahani; Nader Jafarnia Dabanloo; Ali Motie Nasrabadi; Gholamreza Attarodi; Cesar A Teixeira; Antonio Dourado
BackgroundClinical depression is associated with an increased risk for mortality in patients with a recent myocardial infarction (MI). Reduced heartrate variability (HRV) has been suggested as a possible explanation for this association. The purpose of this study was to determine if depression is associated with reduced HRV in patients with a recent MI. Methods and ResultsThree hundred eighty acute
Robert M. Carney; James A. Blumenthal; Phyllis K. Stein; Lana Watkins; Diane Catellier; Lisa F. Berkman; Susan M. Czajkowski; Christopher O'Connor; Peter H. Stone; Kenneth E. Freedland
Effective intrapartum fetal heartrate (FHR) monitoring requires ongoing collaboration among health care providers. Nurses, midwives, and physicians must have a shared understanding of 1) how FHR tracings are interpreted, 2) which FHR patterns are associated with actual or impending fetal acidemia, 3) when and within what time frame the physician or the midwife should be notified of variant FHR
Michael Fox; Sarah Kilpatrick; Tekoa King; Julian T Parer
This paper presents a new measure of heartrate variability (HRV) that can be estimated using Doppler ultrasound techniques and is robust to variations in the angle of incidence of the ultrasound beam and the measurement noise. This measure employs the multiple signal characterization (MUSIC) algorithm which is a high-resolution method for estimating the frequencies of sinusoidal signals embedded in
Kumari L. Fernando; V. John Mathews; Michael W. Varner; Edward B. Clark
Heartrate variability (HRV) provides important information about the development of the cardiovascular system in fetuses. The paper presents a new measure of fetal HRV that can be estimated using Doppler ultrasound techniques. This measure employs the multiple signal characterization (MUSIC) algorithm which is a high-resolution method for estimating the frequencies of sinusoidal signals embedded in white noise from short-duration
K. L. Fernando; V. J. Mathews; M. W. Varner; E. B. Clark
The most common noninvasive method of measuring fetal heartrate (FHR) utilizes pulsed Doppler ultrasound monitors. Linked both to the analog channel and the digital signal processing from today's monitors, different factors influencing the quality of FHR trace are presented. The computerized analysis of acquired FHR signal should minimize the influence of limitations of the indirect measurement method. The proposed
Janusz Jezewski; J. Wrobel; K. Horoba; S. Graczyk; A. Gacek
In order to ensure the accuracy of the fetal heartrate (FHR) obtained from the ultrasound Doppler data, the authors measure the fetal electrocardiogram (ECG) directly and obtain the Doppler data simultaneously. The FHR differences of the Doppler data from the direct ECG data are considerably small, concentrated at 0 bpm (beats per minute), and are practically symmetrical. The distribution
Y. Noguchi; S. Sugimoto; A. Yoshida; H. Kobayashi; M. Kobayashi
An algorithm based on digital filtering, adaptive thresholding, statistical properties in the time domain, and differencing of local maxima and minima has been developed for the simultaneous measurement of the fetal and maternal heartrates from the maternal abdominal electrocardiogram during pregnancy and labor for ambulatory monitoring. A microcontroller-based system has been used to implement the algorithm in real-time. A
The purpose of the present study was to investigate the influence of two exercise intensities (moderate and severe) on heartrate variability (HRV) response in 16 runners 1 hr prior to (-1 hr) and at +1 hr, +24 hr, +48 hr, and +72 hr following each exercise session. Time domain indexes and a high frequency component showed a significant decrease
James, David V. B.; Munson, Steven C.; Maldonado-Martin, Sara; De Ste Croix, Mark B. A.
Measuring heartrate 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 heartrate measurements. In this paper a simple and robust method of measuring the heartrate 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. Heartrate 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.
The study of individual differences in emotional responding can provide considerable insight into interpersonal dynamics and the etiology of psychopathology. Heartrate variability (HRV) analysis is emerging as an objective measure of regulated emotional responding (generating emotional responses of appropriate timing and magnitude). This review provides a theoretical and empirical rationale for the use of HRV as an index of
Thirty five volunteer college women were divided into three groups to determine if heartrate 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
A relationship between fetal heartrate (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
The fetal heartrate (FHR) is monitored on a paper strip (cardiotocogram) during labour to assess fetal health. If necessary, clinicians can intervene and assist with a prompt delivery of the baby. Data-driven computerized FHR analysis could help clinicians in the decision-making process. However, selecting the best computerized FHR features that relate to labour outcome is a pressing research problem. The objective of this study is to apply genetic algorithms (GA) as a feature selection method to select the best feature subset from 64 FHR features and to integrate these best features to recognize unfavourable FHR patterns. The GA was trained on 404 cases and tested on 106 cases (both balanced datasets) using three classifiers, respectively. Regularization methods and backward selection were used to optimize the GA. Reasonable classification performance is shown on the testing set for the best feature subset (Cohen's kappa values of 0.45 to 0.49 using different classifiers). This is, to our knowledge, the first time that a feature selection method for FHR analysis has been developed on a database of this size. This study indicates that different FHR features, when integrated, can show good performance in predicting labour outcome. It also gives the importance of each feature, which will be a valuable reference point for further studies. PMID:24854596
Xu, Liang; Redman, Christopher W G; Payne, Stephen J; Georgieva, Antoniya
Heartrate variability (HRV) is a noninvasive indicator of autonomic control. This study examines HRV changes across a normal menstrual cycle and proposes a novel piecewise function controlling for the effects of breathing on HRV spectral parameters. A resting ECG was collected from 13 women at five points in their menstrual cycle. Both heartrate and breathing rate increased across the cycle (p?.01) while time-domain variability decreased (p?=?.04). Use of the piecewise function for breathing rate in HRV spectral analysis was confirmed by a substantial increase in model goodness-of-fit. HRV spectral parameters, controlled for breathing with the piecewise function, confirm that the decrease in variability is likely due to a parasympathetic withdrawal, since high frequency HRV decreases (p?=?.02). PMID:24942292
Tenan, Matthew S; Brothers, R Matthew; Tweedell, Andrew J; Hackney, Anthony C; Griffin, Lisa
Heartrate variations are tracked using an RF Doppler signal by applying a reassigned joint time-frequency transform (RJTFT). In time-frequency analysis, RJTFT improves the readability of the heartrate on a spectrogram and the heartrate is continuously tracked with it. To verify the result, a heart- beat signal was acquired from a stationary human subject using a Doppler radar
This study has aimed to develop a novel pre-diagnostic tool for primary care screening of heart disease based on multivariate short-term heartrate 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
This study was designed to examine the association of heartrate variability (HRV) with blood glucose levels in a large community-based population. Previous reports have shown HRV to be reduced in diabetics, suggesting the presence of abnormalities in neural regulatory mechanisms. There is scant information about HRV across the spectrum of blood glucose levels in a population-based cohort. One thousand
Jagmeet P Singh; Martin G Larson; Christopher J ODonnell; Peter F Wilson; Hisako Tsuji; Donald M Lloyd-Jones; Daniel Levy
The aim of the study was to investigate whether heartrate variability (HRV) could assess alterations of the autonomic nervous system (ANS) at different levels of excitement. The behavioural and physiological responses of 20 warmblood horses to a challenging ground exercise task were studied. Prior to the experiment, the horses were evaluated at rest and during forward walking (FW). The
T. R. Rietmann; A. E. A. Stuart; P. Bernasconi; M. Stauffacher; J. A. Auer; M. A. Weishaupt
Objectives. This study sought to define the effects of age and gender effects on the normal range of time domain heartrate variability (HRV) over nine decades in healthy subjects.Background. Low HRV is considered an independent marker of mortality risk. However, the age-related decline in HRV may limit its predictive value, particularly in the elderly. Delineation of the range of
Ken Umetani; Donald H Singer; Rollin McCraty; Mike Atkinson
Background Analysis of heartrate variation (HRV) has become a popular noninvasive tool for assessing the activities of the autonomic nervous system (ANS). HRV analysis is based on the concept that fast fluctuations may specifically reflect changes of sympathetic and vagal activity. It shows that the structure generating the signal is not simply linear, but also involves nonlinear contributions. Linear parameters, Power spectral indice (LF/HF) is calculated with nonlinear indices Poincare plot geometry(SD1,SD2), Approximate Entropy (ApEn), Largest Lyapunov Exponent (LLE) and Detrended Fluctuation Analysis(DFA). The results show that, with aging the heartrate variability decreases. In this work, the ranges of all linear and nonlinear parameters for four age group normal subjects are presented with an accuracy of more than 89%. As a pre-analysis step, the HRV data is tested for nonlinearity using surrogate data analysis and the results exhibited a significant difference in the ApEn, LLE, SD1/SD2 and DFA parameters of the actual data and the surrogate data. Methods The heartrate is analyzed using the various time domain parameters, frequency domain parameter and nonlinear parameters like Poincare geometry, ApEn, LLE and DFA. Results In this work, the different linear and nonlinear parameters evaluated show a particular range for various cardiac abnormalities. And the results of these were subjected to 't' test with more than 89% confidence interval giving excellent 'p' values in all cases. Conclusions Heartrate variability (HRV) signal can be used as a reliable indicator of state of the heart. It becomes less random with the aging(less chaotic). This is evaluated by using various time domain, frequency domain and nonlinear parameters like SD1/SD2, ApEn, LLE ?s and ?l. Different ranges of non-linear parameters for various age groups are presented with 'p' value ? 0.12. PMID:15260880
Acharya U, Rajendra; N, Kannathal; Sing, Ong Wai; Ping, Luk Yi; Chua, TjiLeng
Background Heartrate 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] 5670 beats per minute [bpm]) compared with on call (median 81, IQR 7091 bpm, p < 0.001). Increased high-frequency (HF) activity was found precall (median 199, IQR 75365 ms2) compared with on call (median 99, IQR 48177 ms2, p < 0.001). The low-frequency:high-frequency (LF:HF) ratio was lower precall (median 2.7, IQR 1.93.9) than on call (median 4.9, IQR 3.76.5, 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). PMID:25265102
Using a mathematical procedure, we determine appropriate sampling rates for logging heartrate, at a variety of exercise intensities. The mathematical procedure involves correlating exercise and heartrate data to determine a dynamical mathematical model, from which the frequency response of the relationship between exercise intensity and heartrate can be determined. The sampling rate is then straightforwardly deduced by
The human heart normally exhibits robust beat-to-beat heartrate 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 heartrate 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.
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
Background Post-exercise heartrate recovery (HRR) is an index of parasympathetic function associated with clinical outcomes in populations with and without documented coronary heart disease. Decreased parasympathetic activity is thought to be associated with disease progression in chronic heart failure (HF), but an independent association between post-exercise HRR and clinical outcomes among such patients has not been established. Methods and Results We measured HRR (calculated as the difference between heartrate at peak exercise and after 1 minute of recovery) in 202 HF subjects and recorded 17 mortality and 15 urgent transplantation outcome events over 624 days of follow-up. Reduced post-exercise HRR was independently associated with increased event risk after adjusting for other exercise-derived variables (peak oxygen uptake and VE/VCO2 slope), for the Heart Failure Survival Score (adjusted HR 1.09 for one beat/min reduction, 95% CI 1.05-1.13, p<0.0001) and the Seattle Heart Failure Model score (adjusted HR 1.08 for one beat/min reduction, 95% CI 1.05-1.12, p<0.0001). Subjects in the lowest risk tertile based on post-exercise HRR (?30 beats/min) had low risk of events irrespective of the risk predicted by the survival scores. In a subgroup of 15 subjects, reduced post-exercise HRR was associated with increased serum markers of inflammation (interleukin-6 r=0.58, p=0.024, high sensitivity C-reactive protein r=0.66, p=0.007). Conclusions Post-exercise HRR predicts mortality risk in patients with HF and provides prognostic information independent of previously described survival models. Pathophysiologic links between autonomic function and inflammation may be mediators of this association. PMID:19944361
Tang, Yi-Da; Dewland, Thomas A.; Wencker, Detlef; Katz, Stuart D.
The use of spectral techniques to quantify short term heartrate fluctuations on the order of seconds to minutes has helped define the autonomic contributions to beat-to-beat control of heartrate. We used similar techniques to quantify the entire spectrum (0.00003-1.0 Hz) of heartrate variability during 24 hour ambulatory ECG monitoring. The ECG from standard Holter monitor recordings from normal subjects was sampled with the use of a phase locked loop, and a heartrate time series was constructed at 3 Hz. Frequency analysis of the heartrate signal was performed after a nonlinear filtering algorithm was used to eliminate artifacts. A power spectrum of the entire 24 hour record revealed power that was inversely proportional to frequency, 1/f, over 4 decades from 0.00003 to 0.1 Hz (period approximately 10 hours to 10 seconds). Displaying consecutive spectra calculated at 5 minute intervals revealed marked variability in the peaks at all frequencies throughout the 24 hours, probably accounting for the lack of distinct peaks in the spectra of the entire records.
Saul, J. P.; Albrecht, P.; Berger, R. D.; Cohen, R. J.
The aim of the present study is to obtain models for estimating energy expenditure based on the heartrates of people with spinal cord injury without requiring individual calibration. A cohort of 20 persons with spinal cord injury performed a routine of 10 activities while their breath-by-breath oxygen consumption and heartrates were monitored. The minute-by-minute oxygen consumption collected from minute 4 to minute 7 was used as the dependent variable. A total of 7 features extracted from the heartrate signals were used as independent variables. 2 mathematical models were used to estimate the oxygen consumption using the heartrate: a multiple linear model and artificial neural networks. We determined that the artificial neural network model provided a better estimation (r=0.88, MSE=4.4?ml?·?kg(-1)?·?min(-1)) than the multiple linear model (r=0.78; MSE=7.63?ml?·?kg(-1)?·?min(-1)).The goodness of fit with the artificial neural network was similar to previous reported linear models involving individual calibration. In conclusion, we have validated the use of the heartrate to estimate oxygen consumption in paraplegic persons without individual calibration and, under this constraint, we have shown that the artificial neural network is the mathematical tool that provides the better estimation. PMID:24886923
Recent data show that blockade of aldosterone receptors by spironolactone reduces the risk of morbidity and death among patients with severe heart failure. Heart failure secondary to ischemia is characterized by an imbalance of the autonomic nervous system, which can be assessed by analysis of the heartrate variability (HRV). Spironolactones effects on HRV are not well defined. If spironolactone
Mehmet Emin Korkmaz; Haldun Müderriso?lu; Melek Uluçam; Bülent Özin
Power output and heartrate were monitored for 11 months in one female ([Vdot]O2max: 71.5 mL · kg · min) and ten male ([Vdot]O2max: 66.5 ± 7.1 mL · kg · min) cyclists using SRM power-meters to quantify power output and heartrate distributions in an attempt to assess exercise intensity and to relate training variables to performance. In total, 1802 data sets were divided into workout categories according to
Alfred Nimmerichter; Roger G. Eston; Norbert Bachl; Craig Williams
We recorded electroencephalogram (EEG; 6-9 Hz) and heartrate (HR) from infants at 5 and 10 months of age during baseline and performance on the looking A-not-B task of infant working memory (WM). Longitudinal baseline-to-task comparisons revealed WM-related increases in EEG power (all electrodes) and EEG coherence (medial frontal-occipital
Cuevas, Kimberly; Bell, Martha Ann; Marcovitch, Stuart; Calkins, Susan D.
Successful performance in aerobic distance running is dependant on the athlete's ability to cover a fixed distance in the shortest time possible. An effective distance runner's programme must include an exercise prescription specifically developed for the individual athlete. In this regard, a percentage of either measured or predicted maximum heartrate is commonly used to prescribe and measure exercise intensity.
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 heartrate (HR) and lactate (La) responses when designing effective training programs. The aim of this
Jerri Luiz Ribeiro; Caio S. Rosa; Rafael R. Baptist; Alvaro R. Oliveira
Growing evidence suggests that alterations in autonomic function contribute to the pathophysiology of panic disorder (PD). This retrospective study employed 24-h heartrate variability (HRV) analysis of Holter records to compare autonomic function in PD patients (n=38) with healthy, age- and gender-matched controls. Both time and frequency domain measures were calculated, and a circadian rhythm analysis was performed. The SDNN
Rollin McCraty; Mike Atkinson; Dana Tomasino; William P. Stuppy
We have developed light weight miniature ultrasonic sensors for use in FHR (Fetal HeartRate) monitoring. These sensors can be fixed to the maternal abdomen using double sided tape rounds identical to those used in ECG. It is shown that these sensors have performances comparable to traditional sensors while greatly increasing patient comfort and ergonomy in use
B. Karlsson; D. Pourcelot; L. Pourcelot; M. Berson
The aim of this study was to examine the physiological demands and movement patterns of female basketball players after changes in the rules of the game. Nine varsity players were studied during nine official games. Each game was videotaped to identify the frequencies of the main movements performed, heartrate was recorded continuously, and blood samples were collected to determine
A study of 25 male college students (both athletes and nonathletes) who where either regular smokeless tobacco users or nonusers as they performed perceptual-motor tasks revealed significant differences in favor of athletes over nonathletes in terms of reaction time. Tobacco-using subjects showed significant increases in heartrate. (Author/CB)
Summary To investigate the effects of several endoscopic procedures like introduction of the bronchoscope, removal of the instrument, catheter suction, bronchoalveolar lavage and transbronchial biopsy on heartrate, systemic blood pressure, and transcutaneously measured blood gases 77 consecutive patients (age, 2083 years) were studied. All patients received 10 l O2\\/min via face mask during bronchoscopy. Sedation was performed with midazolam
Background: Little is known about autonomic dysfunction in patients with sarcoidosis. Heartrate variability (HRV) studies provide information regarding sympathetic and vagal tone and are both noninvasive and relatively simple to perform. The objective of this study was to compare HRV in sarcoidosis patients and in healthy controls. Methods: We prospectively analyzed data from 12 sarcoidosis patients and 12 healthy
Israel Heller; Aharon Isakov; Ofer Barnea; Joel Greif; Marcel Topilsky
The perception of visceral signals plays a crucial role in many theories of emotions. The present study was designed to investigate the relationship between interoceptive awareness, emotional experience and heartrate responses in an emotional stimulation paradigm. Based on their performance in a heartbeat perception task 38 participants (16 males, 22 females) were classified as subjects with either high (n=19;
Olga Pollatos; Beate M. Herbert; Ellen Matthias; Rainer Schandry
. The authors describe a method that automatically estimates the reliability of ref- erence heartrates (HRr-signs monitors. The reliability is quantitatively expressed through a quality index (QI) for each HRr. Design and their associated HRr. They compared the results of the algorithm against manual analysis performed by human experts
The effect of spinal anesthesia on fetal heartrate is due to maternal hypotension and subsequent fetal hypoxia. Maternal hypotension of 80 mm of mercury for five minutes almost always results in hypoxic fetal bradycardia. This bradycardia is gradual in onset, and may be preceded by a short period of fetal tachycardia. There is a lag in the return of fetal heartrate to normal after maternal blood pressure has normalized. Similar bradycardia has been observed in maternal syncope unassociated with anesthesia. Maternal hypotension should be prevented, and if it occurs should be corrected early. Administration of a vasopressor drug is the treatment of choice, with oxygen and fluids as indicated. ImagesFigure 1.Figure 3.Figure 4.Figure 5. PMID:14084683
Human cardiovascular and/or cardio-respiratory systems are shown to exhibit both multifractal and synchronous dynamics, and we recently developed a nonlinear, physiologically plausible model for the synchronization between heartbeat and respiration (Kotani, et al. Phys. Rev. E 65: 051923, 2002). By using the same model, we now show the multifractality in the heartrate dynamics. We find that beat-to-beat monofractal noise (fractional Brownian motion) added to the brain stem cardiovascular areas results in significantly broader singularity spectra for heartrate through interactions between sympathetic and parasympathetic nervous systems. We conclude that the model proposed here would be useful in studying the complex cardiovascular and/or cardio- respiratory dynamics in humans.
By analyzing cardiac beat-to-beat intervals and interbeat increments, we find that-unlike adults-the difference in the pattern of interbeat increments in healthy and sick newborn infants is more due to a change in the amplitude and much less to a change in the ordering of the interbeat increments. This suggests that very low-frequency elements of neonatal and adult heartrate variability rise from fundamentally different mechanisms.
Aghili, Ali A.; Rizwan-Uddin, Rizwan-Uddin; Griffin, M. Pamela; Moorman, J. Randall
Power spectrum analysis of heart-rate variability was made in seven men [mean age 22 (SEM 1) years] in head-out water immersion\\u000a (W) and in air (A, control) at rest and during steady-state cycling to maximal intensity (maximum oxygen uptake, V?O2max). At rest W resulted in a trebled increase in the total power (P?0.05), coupled with minimal changes in the power
Renza Perini; Stefania Milesi; Luca Biancardi; David R. Pendergast; Arsenio Veicsteinas
Heartrate variability (HRV) can be quantified, among others, in the frequency domain using digital signal processing (DSP) techniques. The wavelet transform is an alternative tool for the analysis of non-stationary signals. The implementation of perfect reconstruction digital filter banks leads to multi resolution wavelet analysis. Software was developed in LabVIEW.In this study, the average power was compared at each
Dieter Verlinde; Frank Beckers; Dirk Ramaekers; André E. Aubert
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 (heartrate) 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
BackgroundBaroreflex-mediated parasympathetic stimulation has variable effects on heartrate variability (HRV). We postulated that a quadratic function would describe the relationship between HRV and parasympathetic effect better than a linear function. Methods and ResultsTwenty-nine normal volunteers (15 women; mean age 39 612 years) were studied after b-adrenergic blockade with intravenous propranolol. Five-minute ECG recordings were made during graded infusions of
Jeffrey J. Goldberger; Sridevi Challapalli; Roderick Tung; Michele A. Parker; Alan H. Kadish
Depression during pregnancy has been associated with a number of adverse outcomes, but the underlying physiological mechanisms\\u000a involved remain unclear. The purpose of this study was to examine the effects of maternal depression during pregnancy on the\\u000a autonomic modulation of heartrate, in a naturalistic setting. Eighty-one pregnant women were studied between 25 and 31 weeks\\u000a of gestation and were identified
Alison K. Shea; Markad V. Kamath; Alison Fleming; David L. Streiner; Keith Redmond; Meir Steiner
to 60 d, ). The mean dive depth and mean dive durationsn p 20 were conservative during nursing ( m and2.1 0.1 0.57 min, Â30.9 m and 0Â5.9 min, respectively). The0.01 range p 0 HR of neonatal pups during the ability to regulate heartrate (HR) during natural breath hold is well developed in neonates (Castellini
This article describes an approach to detecting mental stress using unobtrusive wearable sensors. The approach relies on estimating the state of the autonomic nervous system from an analysis of heartrate variability. Namely, we use a non-linear system identification technique known as principal dynamic modes (PDM) to predict the activation level of the two autonomic branches: sympathetic (i.e. stress-inducing) and
Heartrate variability (HRV) is reduced in patients with chronic obstructive pulmonary disease (COPD). However, the relationships\\u000a among HRV and characteristics of COPD are unknown. The aim of this study was to characterize HRV in patients with COPD and\\u000a to verify the correlation of HRV measured during rest with disease severity and pulmonary, muscular, and functional impairment.\\u000a Thirty-one patients with
Carlos A. Camillo; Fabio Pitta; Heloíse V. Possani; Marcus V. R. A. Barbosa; Divina S. O. Marques; Vinícius Cavalheri; Vanessa S. Probst; Antonio F. Brunetto
Summary Ten subjects (five males, five females) were studied in resting conditions. Ventilation (VT, f, TI, TE), heartrate (HR) and RR interval were recorded or measured. Each subject voluntarily breathed with spontaneous frequency at different ratios of his spontaneous tidal volume (V\\u000aT\\u000ar\\u000a). The results show that sinus arrhythmia increases with lung volume but without effect on mean
The normal range of heartrate (HR) in the first minutes after birth has not been defined.ObjectiveTo describe the HR changes of healthy newborn infants in the delivery room (DR) detected by pulse oximetry.Study DesignAll inborn infants were eligible and included if a member of the research team attended the birth. Infants were excluded if they received any form of
JA Dawson; COF Kamlin; C. Wong; AB te Pas; M. Vento; TJ Cole; SM Donath; SB Hooper; PG Davis; CJ Morley
Direction of changes in heart-rate responses (HRR) were investigated in three separate experiments as a measure of differential\\u000a cognitive and emotional specialization of the cerebral hemispheres. Visual stimuli were presented via the visual half-field\\u000a technique in all three experiments. Slides with different contents were flashed for 200 msec on each trial either to the left\\u000a or right of a center
Kenneth Hugdahl; Mikael Franzon; Britta Andersson; Gunilla Walldebo
In this paper we demonstrate the ability to predict changes to heartrate due to changes in levels of activity, up to an hour into the future. Activity levels are calculated from data collected by a worn accelerometer for a person performing daily activities outside a laboratory enviroment. People with congestive heart failure must take care not to excessively stress
Gordana Velikic; Joseph Modayil; Mike Thomsen; Mark Bocko; Alice Pentland
The original observation that reduced heartrate variability (HRV) confers poor prognosis after myocardial infarction has been followed by many studies of heartrate dynamics. We tested the hypothesis that an entropy-based local dynamics measure gave prognostic information in ambulatory patients undergoing 24-h electrocardiography. In this context, entropy is the probability that short templates will find matches in the time series. We studied RR interval time series from 24-h Holter monitors of 1564 consecutive patients over age 39. We generated histograms of the count of templates as a function of the number of templates matches in short RR interval time series, and found characteristic appearance of histograms for atrial fibrillation, sinus rhythm with normal HRV, and sinus rhythm with reduced HRV and premature ventricular contractions (PVCs). We developed statistical models to detect the abnormal dynamic phenotype of reduced HRV with PVCs and fashioned a local dynamics score (LDs) that, after controlling for age, added more prognostic information than other standard risk factors and common HRV metrics, including, to our surprise, the PVC count and the HRV of normal-to-normal intervals. Addition of the LDs to a predictive model using standard risk factors significantly increased the ROC area and the net reclassification improvement was 27%. We conclude that abnormal local dynamics of heartrate confer adverse prognosis in patients undergoing 24-h ambulatory electrocardiography. PMID:25229393
Moss, Travis J; Lake, Douglas E; Moorman, J Randall
Background: The current study aims at assessment of heartrate variability among children and adolescents with childhood anxiety disorder, using the case-control design. Materials and Methods: The study was carried out at a tertiary care multispecialty hospital. It included 34 children and adolescents with diagnosis of childhood anxiety disorder, in the age range of eight to eighteen years, and 30 age- and sex-matched healthy controls. Heart-rate variability was studied using the standard protocol. Results: Significantly reduced variability of the heartrate was observed in both the time as well as frequency domains in the disorder group as compared to the control group. These findings indicate decreases in the sympathetic and parasympathetic activity in the disorder group, thus representing diminished physiological variability at rest. Conclusions: The notion of autonomic inflexibility, as seen in the current study, has important implications for stability in biological systems. The loss of variability in the physiological systems in general, and in the cardiovascular system in particular, has an association with a number of diseases and dysfunctions. PMID:21814416
Sharma, Rajiv Kumar; Balhara, Yatan Pal Singh; Sagar, Rajesh; Deepak, K. K.; Mehta, Manju
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 heartrate 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.
Heartrate variability (HRV) can be an important indicator of several conditions that affect the autonomic nervous system, including traumatic brain injury, post-traumatic stress disorder and peripheral neuropathy , ,  & . Recent work has shown that some of the HRV features can potentially be used for distinguishing a subject's normal mental state from a stressed one ,  & . In all of these past works, although processing is done in both frequency and time domains, few classification algorithms have been explored for classifying normal from stressed RRintervals. In this paper we used 30 s intervals from the Electrocardiogram (ECG) time series collected during normal and stressed conditions, produced by means of a modified version of the Trier social stress test, to compute HRV-driven features and subsequently applied a set of classification algorithms to distinguish stressed from normal conditions. To classify RR-intervals, we explored classification algorithms that are commonly used for medical applications, namely 1) logistic regression (LR)  and 2) linear discriminant analysis (LDA) . Classification performance for various levels of stress over the entire test was quantified using precision, accuracy, sensitivity and specificity measures. Results from both classifiers were then compared to find an optimal classifier and HRV features for stress detection. This work, performed under an IRB-approved protocol, not only provides a method for developing models and classifiers based on human data, but also provides a foundation for a stress indicator tool based on HRV. Further, these classification tools will not only benefit many civilian applications for detecting stress, but also security and military applications for screening such as: border patrol, stress detection for deception ,, and wounded-warrior triage .
Kaur, Balvinder; Durek, Joseph J.; O'Kane, Barbara L.; Tran, Nhien; Moses, Sophia; Luthra, Megha; Ikonomidou, Vasiliki N.
Prehospital HeartRate and Blood Pressure Increase the Positive Predictive Value of the Glasgow), heartrate (HR), and respiratory rate (RR). We created multi-variate logistic regression models and mortality risk. Key words: blood pressure; Glasgow Coma Scale; heartrate; prehospital; traumatic brain
Wavelet packet modelling of infant sleep state using heartrate data Guy P. Nason,Ã Theofanis classification using heartrate data. The suggested approach produces adequate classification rates when applied, this approach gives us valuable information about the relationship between sleep state and heartrate
The Role of HeartRate in Myocardial Ischemia From Restricted Coronary Perfusion Robert S. Mac, we changed coronary flow rates both suddenly and in controlled sequences and varied the heartrate that heartrate and probably metabolic work create the conditions necessary for subendocardial ischemia
Wavelet packet modelling of infant sleep state using heartrate data Guy P. Nason, y Theofanis classification using heartrate data. The suggested approach produces adequate classification rates when applied, this approach gives us valuable information about the relationship between sleep state and heartrate
Abstract Despite the exponential growth in heartrate variability (HRV) research. The mean heartrate was more reproducible and could be more accu- rately estimated from very short segments be estimated accurately from short segments (Heartrate variability (HRV) Ã? Interbeat
Confronting a Cardiovascular System Model with HeartRate and Blood Pressure Data PE McSharry 1 fluctuations in the heartrate, blood pressure and rate of respiration. Its time evolution is governed the heartrate respectively. A nonlinear delayÂdifferential equation model is constructed to describe
TRIBUTE TO STANLEY DODSON Chytrid infection reduces thoracic beat and heartrate of Daphnia observed simultaneously the heartrates and compared chytrid infected animals with uninfected gravid and non-gravid ones. We found in uninfected animals a thoracic beat rate of 3.81 Â± 018 Hz and a heartrate
Confronting a Cardiovascular System Model with HeartRate and Blood Pressure Data PE McSharry1 fluctuations in the heartrate, blood pressure and rate of respiration. Its time evolution is governed the heartrate respectively. A nonlinear delay-differential equation model is constructed to describe
Three previous studies have shown that biofeedback training is useful in modifying heart-rate and pain ratings during ice water stimulation (cold pressor test). Subjects were given an initial cold pressor followed by heart-rate biofeedback training and a final cold pressor test in which they were instructed to control their heartrate in accordance with the prior training. It was assumed
In anticipation of receiving painful stimuli, 20 female 21-27 yr old Ss learned to control their heartrate when provided with external feedback and reward for criterion heartrate changes and were instructed to increase or decrease their rate. Voluntary slowing of heartrate led to a relative reduction in the perceived aversiveness of the stimuli, particularly for those Ss
The present aim was to explore heartrate responses when stimulating participants with technology primarily aimed at the rehabilitation of older adults. Heartrate responses were measured from 31 participants while they listened to emotionally provoking negative, neutral, and positive musical clips. Ratings of emotional experiences were also collected. The results showed that heartrate responses to negative musical stimuli
Heartrate variability is an important risk factor for cardiovascular disease and all-cause mortality. The acetylcholine pathway plays a key role in explaining heartrate variability in humans. We assessed whether 443 genotyped and imputed common genetic variants in eight key genes (CHAT, SLC18A3, SLC5A7, CHRNB4, CHRNA3, CHRNA, CHRM2 and ACHE) of the acetylcholine pathway were associated with variation in an established measure of heartrate variability reflecting parasympathetic control of the heart rhythm, the root mean square of successive differences (RMSSD) of normal RR intervals. The association was studied in a two stage design in individuals of European descent. First, analyses were performed in a discovery sample of four cohorts (n?=?3429, discovery stage). Second, findings were replicated in three independent cohorts (n?=?3311, replication stage), and finally the two stages were combined in a meta-analysis (n?=?6740). RMSSD data were obtained under resting conditions. After correction for multiple testing, none of the SNPs showed an association with RMSSD. In conclusion, no common genetic variants for heartrate variability were identified in the largest and most comprehensive candidate gene study on the acetylcholine pathway to date. Future gene finding efforts for RMSSD may want to focus on hypothesis free approaches such as the genome-wide association study. PMID:25384021
Riese, Harriette; Munoz, Loretto M.; Hartman, Catharina A.; Ding, Xiuhua; Su, Shaoyong; Oldehinkel, Albertine J.; van Roon, Arie M.; van der Most, Peter J.; Lefrandt, Joop; Gansevoort, Ron T.; van der Harst, Pim; Verweij, Niek; Licht, Carmilla M. M.; Boomsma, Dorret I.; Hottenga, Jouke-Jan; Willemsen, Gonneke; Penninx, Brenda W. J. H.; Nolte, Ilja M.; de Geus, Eco J. C.; Wang, Xiaoling; Snieder, Harold
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 heartrate variability is quantified using multiscale entropy analysis and recurrence analysis. The complexity of the heart beat during mediation is found to be more.
A definition of heart-rate variability (h.r.v.) is given. The use of h.r.v. measurement in both clinical applications and\\u000a the neural cardiovascular research is discussed. For the latter applications, four different signals describing h.r.v. are\\u000a reviewed. It is shown that these signals are based on modifications of one model, namely the integral pulse frequency modulator.\\u000a In Part 2, a hardware device
Autonomic nervous system (ANS) plays an important role in the regulation of the physiological processes of the human organism during normal and pathological conditions. Among the techniques used in its evaluation, the heartrate variability (HRV) has arising as a simple and non-invasive measure of the autonomic impulses, representing one of the most promising quantitative markers of the autonomic balance. The HRV describes the oscillations in the interval between consecutive heart beats (RR interval), as well as the oscillations between consecutive instantaneous heartrates. It is a measure that can be used to assess the ANS modulation under physiological conditions, such as wakefulness and sleep conditions, different body positions, physical training and also pathological conditions. Changes in the HRV patterns provide a sensible and advanced indicator of health involvements. Higher HRV is a signal of good adaptation and characterizes a health person with efficient autonomic mechanisms, while lower HRV is frequently an indicator of abnormal and insufficient adaptation of the autonomic nervous system, provoking poor patient's physiological function. Because of its importance as a marker that reflects the ANS activity on the sinus node and as a clinical instrument to assess and identify health involvements, this study reviews conceptual aspects of the HRV, measurement devices, filtering methods, indexes used in the HRV analyses, limitations in the use and clinical applications of the HRV. PMID:19768301
Vanderlei, Luiz Carlos Marques; Pastre, Carlos Marcelo; Hoshi, Rosângela Akemi; Carvalho, Tatiana Dias de; Godoy, Moacir Fernandes de
12/01/2011 Article 1 1/23 Influence of blood glucose on heartrate and cardiac autonomic function population, the effect of dysglycaemia, insulin resistance and metabolic parameters, on heartrate (HR), HR of HRV. Keywords: diabetes, epidemiology, heartrate, heartrate variability, heartrate recovery inserm
and the mortality benefit of some cardiovascular drugs seems to be related in part to their heartrate-lowering effects. Since it is difficult to separate the benefit of heartrate lowering from other actions with currently available drugs, a 'pure' heartrate-lowering drug would be of great interest in establishing the benefit of heartrate reduction per se. Heartrate
We elucidated the autonomic mechanisms whereby heartrate (HR) is regulated by the muscle metaboreflex. Eight male participants (22 ± 3 years) performed three exercise protocols: (1) enhanced metaboreflex activation with partial flow restriction (bi-lateral thigh cuff inflation) during leg cycling exercise, (2) isolated muscle metaboreflex activation (post-exercise ischaemia; PEI) following leg cycling exercise, (3) isometric handgrip followed by PEI. Trials were undertaken under control (no drug), ?1-adrenergic blockade (metoprolol) and parasympathetic blockade (glycopyrrolate) conditions. HR increased with partial flow restriction during leg cycling in the control condition (?11 ± 2 beats min?1; P < 0.05). The magnitude of this increase in HR was similar with parasympathetic blockade (?11 ± 2 beats min?1), but attenuated with ?-adrenergic blockade (?4 ± 1 beats min?1; P < 0.05 vs. control and parasympathetic blockade). During PEI following leg cycling exercise, HR remained similarly elevated above rest under all conditions (?11 ± 2, ?13 ± 3 and ?9 ± 4 beats min?1, for control, ?-adrenergic and parasympathetic blockade; P > 0.05 between conditions). During PEI following handgrip, HR was similarly elevated from rest under control and parasympathetic blockade (?4 ± 1 vs. ?4 ± 2 beats min?1; P > 0.05 between conditions) conditions, but attenuated with ?-adrenergic blockade (?0.2 ± 1 beats min?1; P > 0.05 vs. rest). Thus muscle metaboreflex activation-mediated increases in HR are principally attributable to increased cardiac sympathetic activity, and only following exercise with a large muscle mass (PEI following leg cycling) is there a contribution from the partial withdrawal of cardiac parasympathetic tone. PMID:23713032
Fisher, James P; Adlan, Ahmed M; Shantsila, Alena; Secher, J Frederik; S?rensen, Henrik; Secher, Niels H
Background Data from large epidemiological studies suggest that elevated heartrate is independently associated with cardiovascular and all-cause mortality in patients with hypertension and in those with established cardiovascular disease. Clinical trial findings also suggest that the favorable effects of beta-blockers and other heartratelowering agents in patients with acute myocardial infarction and congestive heart failure may be, at least in part, due to their heartratelowering effects. Contemporary clinical outcome prediction models such as the Global Registry of Acute Coronary Events (GRACE) score include admission heartrate as an independent risk factor. Aims This article critically reviews the key epidemiology concerning heartrate and cardiovascular risk, potential mechanisms through which an elevated resting heartrate may be disadvantageous and evaluates clinical trial outcomes associated with pharmacological reduction in resting heartrate. Conclusions Prospective randomised data from patients with significant coronary heart disease or heart failure suggest that intervention to reduce heartrate in those with a resting heartrate >70 bpm may reduce cardiovascular risk. Given the established observational data and randomised trial evidence, it now appears appropriate to include reduction of elevated resting heartrate by lifestyle +/? pharmacological therapy as part of a secondary prevention strategy in patients with cardiovascular disease. PMID:22954325
Menown, Ian BA; Davies, Simon; Gupta, Sandeep; Kalra, Paul R; Lang, Chim C; Morley, Chris; Padmanabhan, Sandosh
Elevated resting heartrate 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 heartrate 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 heartrate 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 heartrate is associated with altered cardiac conduction and reduced risk of sick sinus syndrome, and both heartrateincreasing and heartratedecreasing variants associate with risk of atrial fibrillation. Our findings provide fresh insights into the mechanisms regulating heartrate and identify new therapeutic targets. PMID:23583979
den Hoed, Marcel; Eijgelsheim, Mark; Esko, Tonu; Brundel, Bianca J J M; Peal, David S; Evans, David M; Nolte, Ilja M; Segre, Ayellet V; Holm, Hilma; Handsaker, Robert E; Westra, Harm-Jan; Johnson, Toby; Isaacs, Aaron; Yang, Jian; Lundby, Alicia; Zhao, Jing Hua; Kim, Young Jin; Go, Min Jin; Almgren, Peter; Bochud, Murielle; Boucher, Gabrielle; Cornelis, Marilyn C; Gudbjartsson, Daniel; Hadley, David; Van Der Harst, Pim; Hayward, Caroline; Heijer, Martin Den; Igl, Wilmar; Jackson, Anne U; Kutalik, Zoltan; Luan, Jian'an; Kemp, John P; Kristiansson, Kati; Ladenvall, Claes; Lorentzon, Mattias; Montasser, May E; Njajou, Omer T; O'Reilly, Paul F; Padmanabhan, Sandosh; Pourcain, Beate St.; Rankinen, Tuomo; Salo, Perttu; Tanaka, Toshiko; Timpson, Nicholas J; Vitart, Veronique; Waite, Lindsay; Wheeler, William; Zhang, Weihua; Draisma, Harmen H M; Feitosa, Mary F; Kerr, Kathleen F; Lind, Penelope A; Mihailov, Evelin; Onland-Moret, N Charlotte; Song, Ci; Weedon, Michael N; Xie, Weijia; Yengo, Loic; Absher, Devin; Albert, Christine M; Alonso, Alvaro; Arking, Dan E; de Bakker, Paul I W; Balkau, Beverley; Barlassina, Cristina; Benaglio, Paola; Bis, Joshua C; Bouatia-Naji, Nabila; Brage, S?ren; Chanock, Stephen J; Chines, Peter S; Chung, Mina; Darbar, Dawood; Dina, Christian; Dorr, Marcus; Elliott, Paul; Felix, Stephan B; Fischer, Krista; Fuchsberger, Christian; de Geus, Eco J C; Goyette, Philippe; Gudnason, Vilmundur; Harris, Tamara B; Hartikainen, Anna-liisa; Havulinna, Aki S; Heckbert, Susan R; Hicks, Andrew A; Hofman, Albert; Holewijn, Suzanne; Hoogstra-Berends, Femke; Hottenga, Jouke-Jan; Jensen, Majken K; Johansson, Asa; Junttila, Juhani; Kaab, Stefan; Kanon, Bart; Ketkar, Shamika; Khaw, Kay-Tee; Knowles, Joshua W; Kooner, Angrad S; Kors, Jan A; Kumari, Meena; Milani, Lili; Laiho, Paivi; Lakatta, Edward G; Langenberg, Claudia; Leusink, Maarten; Liu, Yongmei; Luben, Robert N; Lunetta, Kathryn L; Lynch, Stacey N; Markus, Marcello R P; Marques-Vidal, Pedro; Leach, Irene Mateo; McArdle, Wendy L; McCarroll, Steven A; Medland, Sarah E; Miller, Kathryn A; Montgomery, Grant W; Morrison, Alanna C; Muller-Nurasyid, Martina; Navarro, Pau; Nelis, Mari; O'Connell, Jeffrey R; O'Donnell, Christopher J; Ong, Ken K; Newman, Anne B; Peters, Annette; Polasek, Ozren; Pouta, Anneli; Pramstaller, Peter P; Psaty, Bruce M; Rao, Dabeeru C; Ring, Susan M; Rossin, Elizabeth J; Rudan, Diana; Sanna, Serena; Scott, Robert A; Sehmi, Jaban S; Sharp, Stephen; Shin, Jordan T; Singleton, Andrew B; Smith, Albert V; Soranzo, Nicole; Spector, Tim D; Stewart, Chip; Stringham, Heather M; Tarasov, Kirill V; Uitterlinden, Andre G; Vandenput, Liesbeth; Hwang, Shih-Jen; Whitfield, John B; Wijmenga, Cisca; Wild, Sarah H; Willemsen, Gonneke; Wilson, James F; Witteman, Jacqueline C M; Wong, Andrew; Wong, Quenna; Jamshidi, Yalda; Zitting, Paavo; Boer, Jolanda M A; Boomsma, Dorret I; Borecki, Ingrid B; Van Duijn, Cornelia M; Ekelund, Ulf; Forouhi, Nita G; Froguel, Philippe; Hingorani, Aroon; Ingelsson, Erik; Kivimaki, Mika; Kronmal, Richard A; Kuh, Diana; Lind, Lars; Martin, Nicholas G; Oostra, Ben A; Pedersen, Nancy L; Quertermous, Thomas; Rotter, Jerome I; van der Schouw, Yvonne T; Verschuren, W M Monique; Walker, Mark; Albanes, Demetrius; Arnar, David O; Assimes, Themistocles L; Bandinelli, Stefania; Boehnke, Michael; de Boer, Rudolf A; Bouchard, Claude; Caulfield, W L Mark; Chambers, John C; Curhan, Gary; Cusi, Daniele; Eriksson, Johan; Ferrucci, Luigi; van Gilst, Wiek H; Glorioso, Nicola; de Graaf, Jacqueline; Groop, Leif; Gyllensten, Ulf; Hsueh, Wen-Chi; Hu, Frank B; Huikuri, Heikki V; Hunter, David J; Iribarren, Carlos; Isomaa, Bo; Jarvelin, Marjo-Riitta; Jula, Antti; Kahonen, Mika; Kiemeney, Lambertus A; van der Klauw, Melanie M; Kooner, Jaspal S; Kraft, Peter; Iacoviello, Licia; Lehtimaki, Terho; Lokki, Marja-Liisa L; Mitchell, Braxton D; Navis, Gerjan; Nieminen, Markku S; Ohlsson, Claes; Poulter, Neil R; Qi, Lu; Raitakari, Olli T; Rimm, Eric B; Rioux, John D; Rizzi, Federica; Rudan, Igor; Salomaa, Veikko; Sever, Peter S; Shields, Denis C; Shuldiner, Alan R; Sinisalo, Juha; Stanton, Alice V; Stolk, Ronald P; Strachan, David P; Tardif, Jean-Claude; Thorsteinsdottir, Unnur; Tuomilehto, Jaako; van Veldhuisen, Dirk J; Virtamo, Jarmo; Viikari, Jorma; Vollenweider, Peter; Waeber, Gerard; Widen, Elisabeth; Cho, Yoon Shin; Olsen, Jesper V; Visscher, Peter M; Willer, Cristen; Franke, Lude; Erdmann, Jeanette; Thompson, John R; Pfeufer, Arne; Sotoodehnia, Nona; Newton-Cheh, Christopher; Ellinor, Patrick T; Stricker, Bruno H Ch; Metspalu, Andres; Perola, Markus; Beckmann, Jacques S
This study examined how activity type influenced heartrates and time spent in target heartrate zones of high school students participating in physical education classes. Significantly higher average heartrates 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.
Students commonly test the effects of chemical agents on the heartrate 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 heartrate in "Daphnia." Ethanol at 5% and 10% (v/v) reduced mean heartrate to
The present longitudinal study examined resting heartrate and heartrate 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 heartrate
Bimmel, Nicole; van IJzendoorn, Marinus H.; Bakermans-Kranenburg, Marian J.; Juffer, Femmie; De Geus, Eco J. C.
Dynamics analysis of RR interval behavior and traditional measures of heartrate variability were compared between postinfarction patients with and without vulnerability to ventricular tachyarrhythmias in a case-control study. Short-term fractal correlation of heartrate dynamics was better than traditional measures of heartrate variability in differentiating patients with and without life-threatening arrhythmias.
Makikallio, T. H.; Seppanen, T.; Airaksinen, K. E.; Koistinen, J.; Tulppo, M. P.; Peng, C. K.; Goldberger, A. L.; Huikuri, H. V.
Heartrate variability (HRV) provides a noninvasive means of quantifying cardiac autonomic activity. Imbalances in autonomic activity between the sympathetic and parasympathetic systems accompany a number of cardiac disorders. This paper provides new results in mathematically modeling the cardiac nervous system responsible for fluctuations in heartrate. These results clearly demonstrate the differing varieties of heartrate fluctuations over a
Uncorrelated Randomness of the HeartRate Is Associated with Sepsis in Sick Premature Infants Alain.1159/000208792 Key Words Bacterial infection Computer-assisted diagnosis Heartrate variability Sepsis Abstract are needed. Objectives: It was the aim of this study to determine if heartrate (HR) behavior may help
HEARTRATE AND BLOOD PRESSURE VARIABILITY UNDER MOON, MARS AND ZERO GRAVITY CONDITIONS DURING), studied via the heartrate variability (HRV) and blood pressure variability (BPV). HRV and BPV were predominant during reduced gravity. For the mean heartrate, a non-monotonic relation was found, which can
Stress Classification by Separation of Respiratory Modulations in HeartRate Variability using of respiration on the heartrate is a phenomenon known as respiratory sinus arrhythmia. However, effects of respiration are often ignored in studies of heartrate variability. In this paper, we take respiratory
halÂ00176298, version 2 Â 26 Mar 2008 A new stochastic process to model HeartRate series during; Hurst parameter; LongÂrange dependence processes; Heartrate time series 1. Introduction The content. heartrate (HR) data during the race. The following #28;gure provides several examples of such data
Neonatology. Author manuscript Page /1 7 Uncorrelated Randomness of the HeartRate Is Associated markers are needed. Objectives It was the aim of this study to determine if heartrate (HR) behavior may Keywords Bacterial infection ; Computer-assisted diagnosis ; Heartrate variability ; Sepsis Introduction
ORIGINAL PAPER Environment and feeding change the ability of heartrate to predict metabolism 2010 / Published online: 12 August 2010 Ã? Springer-Verlag 2010 Abstract The ability to use heartrate of physiological, behavioral, and environmental states. Keywords Steller sea lion Ã Heartrate Ã Oxygen consumption
Reliability and Accuracy of HeartRate Variability Metrics Versus ECG Segment Duration J. McNames1, Oregon Health & Science University, Portland, OR, USA Abstract-- Heartrate variability (HRV) has been used in many studies to assess the effects of autonomic regulation on the heartrate. A 1996 task force
ORIGINAL PAPER Environment and feeding change the ability of heartrate to predict metabolism 2010 ï¿½ Springer-Verlag 2010 Abstract The ability to use heartrate (fh) to predict oxygen consumption, and environmental states. Keywords Steller sea lion ï¿½ Heartrate ï¿½ Oxygen consumption ï¿½ Heat increment of feeding
Instantaneous changes in heartrate regulation due to mental load in simulated office work Joachim), in addition to the traditional linear heartrate variability (HRV) parameters. In a laboratory environment, 43 condition. The heartrate and measures related to the vagal modulation could differentiate the active
Nonlinear HeartRate Variability in a Healthy Population: Influence of Age S Vandeput1 , B Universiteit Leuven, Belgium Abstract Heartrate variability (HRV) measurements are used as markers of autonomic modulation of heartrate. Numerical noise titration was applied to a large healthy population
Moving with the beat: heartrate and visceral temperature of free-swimming and feeding bluefin tuna (Thunnus maccoyii ) to measure changes in the heartrate ( fH) and visceral temperature (TV) during a two, greater relative heart masses, elevated metabolic rates, and are more difficult to handle than tropical
ORIGINAL PAPER Modeling HeartRate Regulation--Part I: Sit-to-stand Versus Head-up Tilt Mette S+Business Media, LLC 2007 Abstract In this study we describe a model predicting heartrate regulation during of sympathetic and parasympathetic outflow, are then used to estimate the heartrate response. Dynamics
Heartrate dynamics during three forms of meditation C.-K. Penga,*, Isaac C. Henrya , Joseph E Objective: This study was designed to quantify and compare the instantaneous heartrate dynamics patterns. Background: We analyzed beat-to-beat heartrate and continuous breathing signals from 10
Heartrate variability in preterm neonates with and without abnormal cardiorespiratory events The heartrate variability (HRV) of preterm neonates undergoing a polysomnography is ana- lyzed in relation experience abnormal cardiorespiratory events, based only on the heartrate recordings during periods without
and resting heartrate on mortality: the Whitehall II prospective cohort study Hermann Nabi 1 2 * , Mika Kivim symptoms and resting heartrate (RHR) on mortality. Methods Data come from 5936 participants, aged 61 6 improve survival. Author Keywords depression ; resting heartrate and mortality INTRODUCTION Depression
Wrapper subset evaluation facilitates the automated detection of diabetes from heartrateheartrate variability measures. These data are well suited to the diagnosis of cardiac dysfunction that the detection of diabetes is feasible from heartrate variability measures. D. J. Cornforth, H. F. Jelinek, M. C
Multifractal Analysis of Fetal HeartRate Variability in Fetuses with and without Severe Acidosis multifractal analysis of fetal heartrate (FHR) variability in fetuses with and without acidosis during labor and nonacidotic fetuses, independently from FHR pattern. KEYWORDS: Acidosis, fetal heartrate, labor, multifractal
Compared a traditional and an alternative (skill-fitness- music) fitness teaching format to determine whether there would be differences on Hong Kong middle school students' heartrate intensity and perceived enjoyment. Data from heartrate monitors and student surveys indicated that the two formats did not produce differences in heartrates.
Effects of lying or standing on mammary blood flow and heartrate of dairy cows H Rulquin, JP of standing or lying on the mammary blood flow and heartrate in dairy cows. To widen the range of blood flow on the left common ex- ternal pudic artery by a transit-time blood flowmeter. Heartrate was determined
Characterizing heartrate variability by scale-dependent Lyapunov exponent Jing Hu,1,2 Jianbo Gao,1; accepted 18 May 2009; published online 30 June 2009 Previous studies on heartrate variability HRV using, since heartrate variability (HRV) may exhibit both nonlinear, and possibly chaotic, as well
HeartRate Regulation processed through wavelet analysis and change detection. Some case studies-mail: email@example.com December 29, 2010 Abstract Heartrate variability (HRV) is an indicator to be completed by further studies. Keywords: HeartRate Variability; Ecological conditions; Locally stationary
Large deviations estimates for the multiscale analysis of heartrate variability$,$$ Patrick physiological factors impacting the heartrate variability. Notwithstanding these considerable progresses, multi the relevance of this approach, on both theoretical objects and on human heartrate signals from the Physionet
Accurate R Peak Detection and Advanced Preprocessing of Normal ECG for HeartRate Variability, The Netherlands Abstract Heartrate variability (HRV) analysis is well-known to give information about the autonomic heartrate modula- tion mechanism. In order to avoid erroneous conclusions, it is of great
Multiscale Analysis of HeartRate Variability: A Comparison of Different Complexity Measures JING; published online 12 December 2009) Abstract--Heartrate variability (HRV) is an important dynamical variable parameter, the sample entropy, and the multiscale entropy. Keywords--Heartrate variability, Cardiovascular
In vivo cardiac phase response curve elucidates human respiratory heartrate variability Published-related variation of the heartrate by S. Hales in 1733 and its first registration by C. Ludwig in 1847 , cardio of heartrate variability has become important in many medical fields as a diagnostically
Effects of parasympathetic blockade on nonlinear dynamics of heartrate in mice Jean Clairambault, Pascale Mansier, Bernard Swynghedauw Abstract-- The complexity of the heartrate series has been assessed. The resulting parasympathetic blockade produced an increase in the com- plexity of the heartrate (RR) series
Large deviations estimates for the multiscale analysis of heartrate variability$,$$ Patrick to characterize relevant physiological factors impacting the heartrate variability. Notwithstanding. In this article, we illustrate the relevance of this approach, on both theoretical objects and on human heartrate
ABSTRACT An Enhanced Signal Processing Strategy For Fetal HeartRate Detection Charles Brewton Old the signal processing strategy for an acoustic fetal heartrate monitor. The theory, implementation, and testing of several possible signal processing strategies for fetal heartrate detection are presented
1996 International Conference on Parallel Processing Analysis of HeartRate Variability. The algorithm is used to compute the Kz entropy and correlation di- mension of experimental heartrate data (an be used as a measure of the heartrate variability and the level of chaos present in
Cardiovascular control after spaceflight 1 Adaptation of the autonomic heartrate regulation postflight recovery of linear and nonlinear neural markers of heartrate modulation, with a special focus from linear and nonlinear heartrate variability (HRV) parameters, separately during 2h day and 2h
A novel technique for measuring heartrate in a free swimming marine vertebrate Andrew E. Myers a.1 mm) are caused by the movement of blood through the nearby blood vessels. Putative heartrate also comparable to the heartrate recorded in leatherbacks by means of implanted electrodes. We
DIFFERENT PATTERNS OF AUTONOMIC HEARTRATE CONTROL DURING HYPOXIA IN FETAL AND NEWBORN LAMBS A of heartrate (HR) during hypoxia was studied longitudinally in nine unanaesthetised fetal lambs (109 days recovery. Changes in heartrate (! HR) during hypoxia were age-dependent; before 120 days gestation 0 HR
ORAL PRESENTATION ABSTRACT Design of HeartRate and Blood Oxygen Saturation Monitoring Device to a processing centre wirelessly, where it can be monitored and forwarded to necessary personnel. Heartrate signal. This technique is called Photoplethysmography (PPG), and can be used to calculate the heartrate
A Robust Method to Estimate Instantaneous HeartRate from Noisy Electrocardiogram Waveforms ANDREI for real-time esti- mation of instantaneous heartrate (HR) from noise-laden electrocardiogram (ECG of instantaneous heartrate (HR) is one of the most vexing problems in physiological measurements.4
Analysis of Physiological Meaning of Detrended Fluctuation Analysis in HeartRate Variability Using Fluctuation Analysis (DFA), have been widely used for quantifying the HeartRate Variability (HRV) for cardiac lumped parameter models. 1. Introduction During the last years, HeartRate Variability (HRV) sig- nal has
Time-Frequency Relationships between HeartRate and Respiration: A Diagnosis Tool for Late Onset of the laboratory tests, including CRP and blood culture, have high predictive accuracy. Heartrate variability (HRV. The objective of this study was to determine if analysis of time-frequency correlations between the heartrate
Methodology for Multifractal Analysis of HeartRate Variability: From LF/HF Ratio to Wavelet introduction to the practical use of wavelet Leader based multifractal analysis to study heartrate variability to other standard characterizations of heartrate variability: (mono)fractal analysis, Hurst exponent
Physica A 249 (1998) 587Â593 Scaling and universality in heartrate variability distributions P.V. All rights reserved. Time series of beat-to-beat (RR) heartrate intervals obtained from digitized erent (e.g. smaller) during illness, the pattern of heartrate variability might be otherwise very
Spectral and symbolic analysis of HeartRate data during Tilt Test Camillo Cammarota Enrico Rogora Abstract Spectral analysis of heartrate sequences is commonly used to inves- tigate neuroauthonomic control of heartrate by means of two indexes, the low and the high frequency power. For tilt test data
Objective: Heartrate plays an important role in compensatory conditions of arterial pressure changes. Very little information, however, exists on its role in the dynamic adjustment of stimulated organ perfusion. We studied the influence of heartrate on the activity-flow coupling mechanism which adapts local cerebral blood flow in accordance with cortical activity. Since it does not affect heartrate
Various combinations of sympathetic and vagal tone can yield the same heartrate, while ventricular electrophysiology differs. To demonstrate this in humans, we studied healthy volunteers in the sitting position with horizontal legs. First, heartrate was increased by lowering the legs to 60° and back. Thereafter, heartrate was increased by handgrip. In each subject, a leg-lowering angle was
Joost Frederiks; Cees A. Swenne; Jan A. Kors; Gerard van Herpen; Arie C. Maan; Jeroen V. Levert; Martin J. Schalij; Albert V. G. Bruschke
Several epidemiological studies have reported that an elevated heartrate is associated with coronary atherosclerosis independently of other risk factors. In this review we explore the pathophysiologic mechanisms involved in the pro-atherosclerotic effect of elevated heartrate, apart from its association with sympathetic tone. An elevated heartrate enhances the magnitude and frequency of the tensile stress imposed on the
George D. Giannoglou; Yiannis S. Chatzizisis; Chrysanthos Zamboulis; George E. Parcharidis; Dimitri P. Mikhailidis; George E. Louridas
The relationship between heartrate reactivity and atherogenesis is examined. Data from empirical studies are presented which support theoretical suggestions that it is the heartrate itself rather than the increase in heartrate following the onset of a stressor which is causally related to the development of arterial atherosclerosis. Several directions for research which will clarify this issue are
The effectiveness of cardiac education and visual biofeedback of heartrate as a training procedure to teach people to control their heartrate to a psychological stressor was investigated with 36 students, half of whom acted as control subjects. Training took 5 weeks and consisted of 30-min per week of awareness training, plus exercises to increase and decrease heartrate
Research in human operant heartrate conditioning concerned with the elucidation of the mediators of operant heartrate changes has postulated five mediating mechanisms related to operant heartrate change: respiratory, somatic-muscular, central neurological, cognitive and dispositional (personality). However, examination of the literature indicates that much of this research has produced equivocal results, hence, a clear picture of mediation has
Brain Areas Controlling HeartRate Variability in Tinnitus and Tinnitus-Related Distress Sven in the central control of heartrate variability in tinnitus patients. Whereas the sympathovagal balance HeartRate Variability in Tinnitus and Tinnitus-Related Distress. PLoS ONE 8(3): e59728. doi:10
HEARTRATE AND BLOOD PRESSURE VARIABILITY UNDER MOON, MARS AND ZERO GRAVITY CONDITIONS DURING via the heartrate variability (HRV) and blood pressure variability (BPV). HRV and BPV were assessed in this study to assess the heartrate variability (HRV) and blood pres- sure variability (BPV). Due to gravity
Although the fetal heartrate monitoring using ultrasound is widely used it is still not optimized for automatic measurements due to the complexity of the Doppler signal. This paper presents a new fetal heartrate (FHR) detecting algorithm, using sampling auto-correlation approach. The results obtained using the custom-built ultrasonic Doppler fetal heartrate monitoring system are presented and confirm the
In small animals studies, sick animals often have a significant reduction in heartrate while under anesthesia. The influence of heartrate reduction on Doppler myocardial imaging (DMI) parameters is not known. The aim of the present study was to assess the effect of heartrate reduction on DMI parameters in a small animal model. Twenty-four rats underwent transthoracic echocardiography
C. Weytjens; J. D'hooge; S. Droogmans; A. Van den Bergh; B. Cosyns; T. Lahoutte; P. Herijgers; G. Van Camp
Examined the ability of 32-week human fetuses to learn and recall information. Found a significant heartrate habituation pattern for a series of vibroacoustic stimuli. After a single novel stimulus, the heartrate to stimulus 1 reemerged. Uterine contractions were not related to presentation of the novel stimulus or change in heartrate after the
Sandman, Curt A.; Wadhwa, Pathik; Hetrick, William; Porto, Manuel; Peeke, Harmon V. S.
A model to analyze resemblances of twins and parents using LISREL is outlined and applied to sports participation and heart-rate data. Sports participation and heartrate were measured in 44 monozygotic and 46 dizygotic adolescent twin pairs and in their parents. Genetic factors influence variation in both sports behavior and heartrate, while there is no evidence for transmission from
D. I. Boomsma; M. B. M. van den Bree; J. F. Orlebeke; P. C. M. Molenaar
Heartrate reactivity to a 2 minute mental arithmetic stressor delivered under timed and competitive conditions and graded for age-related difficulty was collected on 148 males and 153 females grouped into five age cohorts ranging from 7 to 20 years. Data on resting heartrate, heartrate during the stressor period, and post-stressor recovery showed significant sex (females had higher
The purpose of the present study was to examine the relationship between oxygen uptake (VO[subscript 2]) and heartrate (HR) responses during rest and exercise in Chinese children and youth and to evaluate the relationships between maximal heartrate (%HRmax), heartrate reserve (%HRR), peak oxygen uptake (%VO[subscript 2]peak), and oxygen uptake
Some nonlinear characteristics of heartrate variability in the course of functional tests with physical exercise are described.\\u000a Two groups of volunteers participated in the tests: a control group of 32 healthy subjects (group 1) and a group of 35 coronary\\u000a heart disease (CHD) patients (group 2). Two series of experiments were performed for each group. An active orthostatic test
The present study examined the predicted positive and linear relationship (Iwanaga, 1995a, 1995b) between exercise heartrate 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 = 20.3 years, SD = 1.2) selected the music of a single artist from the three highest-rated artists from the earlier survey. They reported their preference for slow, medium, and fast tempo selections from each artist for three treadmill walking conditions at 40%, 60%, and 75% maximal heartrate reserve. A mixed-model 3 x 3 x 2 (Exercise Intensity x Music Tempo x Gender) analysis of variance was used to analyze the data. Results indicated there was no three-way interaction for music preference. There was, however, a significant (p < .05) two-way interaction for Exercise Intensity x Music Tempo (partial eta2 = .09) and a significant (p < .05) main effect for music tempo, with large differences evident between preference for medium versus slow tempo and fast versus slow tempo music at all exercise intensities (partial eta2 = .78). Participants reported a preference for both medium and fast tempo music at low and moderate exercise intensities and for fast tempo music at high intensity. Only partial support was found for the expected linear relationship between exercise intensity and music tempo preference. PMID:16898279
Karageorghis, Costas I; Jones, Leighton; Low, Daniel C
Aim The aim of this investigation was to explore the correlation of shisha smoking with blood pressure and heartrate values.\\u000a \\u000a \\u000a \\u000a Subjects and methods This is a randomized cross-sectional epidemiological study involving a total of 14,310 adults selected from various regions\\u000a of Jordan. Well-trained pharmacy students interviewed participants in outpatient settings. The frequencies of water-pipe-smoking\\u000a males and females in the sample were
Saafan A. Al-Safi; Nehad M. Ayoub; Mosab A. Albalas; Imad Al-Doghim; Faisal H Aboul-Enein
Experiments were performed on 24 men and women (aged 20-27 yr) in three equal groups who were taught to control their own heartrates by autogenic training and biofeedback under dark and sound-isolated conditions. Group I was parasympathetic dominant, group II was sympathetic dominant, and group III consisted of parasympathetic-dominant subjects and controls who received only biofeedback of their own heartrates. The results corroborate three hypotheses: (1) subjects with para-sympathetic-dominant autonomic profiles perform in a way that is both qualitatively and quantitatively different from subjects with sympathetic-dominant autonomic profiles; (2) tests of interindividual variability yield data relevant to individual performance in visceral learning tasks; and (3) the combined use of autogenic training, biofeedback, and verbal feedback is suitable for conditioning large stable autonomic responses in humans.
Differential heartrates during heating and cooling (heartrate hysteresis) are an important thermoregulatory mechanism in ectothermic reptiles. We speculate that heartrate hysteresis has evolved alongside vascularisation, and to determine whether this phenomenon occurs in a lineage with vascularised circulatory systems that is phylogenetically distant from reptiles, we measured the response of heartrate to convective heat transfer in the Australian freshwater crayfish, Cherax destructor. Heartrate during convective heating (from 20 to 30 degrees C) was significantly faster than during cooling for any given body temperature. Heartrate declined rapidly immediately following the removal of the heat source, despite only negligible losses in body temperature. This heartrate 'hysteresis' is similar to the pattern reported in many reptiles and, by varying peripheral blood flow, it is presumed to confer thermoregulatory benefits particularly given the thermal sensitivity of many physiological rate functions in crustaceans. PMID:15313496
Goudkamp, Jacqueline E; Seebacher, Frank; Ahern, Mark; Franklin, Craig E
The purpose of this study was to investigate the relationship between heartrate and oxygen consumption (VO2) during the performance of unsupported and supported deep water running (DWR) in young healthy males and females. A second purpose was to compare regression of predicted VO2 on heartrate between the two methods of support (i.e., unsupported vs vest supported). Thirty?three college?aged
Stanley P. Brown; Dana ODonnell; Leonard Kravitz; Kim Beason; John Alvarez
Background Non-alcoholic fatty liver disease (NAFLD) has been considered as a benign disease often associated with central obesity and insulin resistance and, in general, with factors of the metabolic syndrome. Heartrate recovery after exercise is a function of vagal reactivation, and its impairment is an independent prognostic indicator for cardiovascular and all-cause mortality. The aim of our study was to evaluate the heartrate recovery index in patients with NAFLD. Material/Methods The study population included 59 patients with NAFLD (mean age=42.3±9.3 years) and 22 healthy subjects as controls (mean age=40.7±6.5 years). Basal electrocardiography, echocardiography, and treadmill exercise testing were performed on all patients and controls. The heartrate recovery index was defined as the reduction in the heartrate from the rate at peak exercise to the rate at the 1st minute (HRR1), 2nd minute (HRR2), 3rd minute (HRR3), and 5th minute (HRR5) after stopping exercise stress testing. Results There were significant differences in HRR1 and HRR2 indices between patients with ED and the control group (19.9±8.2 vs. 34.1±9.6; p<0.001 and 24.3±5.4 vs. 40.5±9.1; p=0.006, respectively). Similarly, HRR indices after the 3rd and 5th minutes of the recovery period were significantly lower in patients with NAFLD compared with those indices in the control group (32.3±8.5 vs. 58.4±6.5; p=0.001 and 58±18.2 vs. 75.1±15.8; p<0.001). Effort capacity was markedly lower (11±1.9 vs. 12.5±1.5 METs; p=0.001) among the patients with NAFLD. Conclusions The heartrate recovery index is deteriorated in patients with NAFLD. When the prognostic significance of the heartrate recovery index is considered, these results may help explain the increased occurrence of cardiac death. It points to the importance of the heartrate recovery index in the identification of high-risk patients. PMID:25168159
A variable heartbeat was considered a sign of good health by ancient Asian physicians. Today, new computer-based methods (e.g., Fire of Life analysis) allow quantification of heartrate and heartrate variability during acupuncture. The objective of this article is to compare different acupuncture methods to evaluate the influence of acupuncture on heart rhythm in short-term and long-term measurements. There
The relationship between unstable angor (angina) and circadian periodicity of heartrate variability (HRV) was explored in a group of patients hospitalized in a coronary care unit (CCU). Patients were classified as normal (whose symptoms had non-cardiovascular origin, n=8), moderate angor (n=13) and severe angor (n=11). A fourth group of ambulatory healthy volunteers (n=12) was included. Individual 24 h Holter records were analyzed, mean RR and standard deviation of RR (SDNN) being obtained from 1 h-length windows. For frequency domain analysis, 5 min-length windows were employed. The spectral components analyzed were total power (spectral power between 0.01 and 0.5 Hz), low frequency power (LF: power between 0.04 and 0.15 Hz), and high frequency power (HF: power between 0.15 and 0.4 Hz). In addition, LF to HF areas ratio (L/H) was computed. Mesor, amplitude and acrophase for every 24 h rhythm were calculated by cosinor analysis. As compared to ambulatory controls, admission to the CCU diminished amplitude and phase-delayed the circadian oscillation of most HRV parameters, except for SDNN. Moderate angor patients showed decreased amplitude of RR and L/H and augmented amplitude of SDNN when compared to normal hospitalized subjects. A phase delay of about 1.5 h for RR intervals and a phase advance of 3.5-6 h for LFA and SDNN were found in the moderate angor group when compared to normal. Amplitude of 24 h variation of total power decreased in severely angor patients and the circadian oscillation of HF (an indicator of vagal control on the heart) became free running. A phase delay of 2.5 h in SDNN acrophase was found in severely affected patients when compared to moderate. The results indicate that severity of unstable angor correlates with desynchronization of parasympathetic control of heartrate. PMID:15944873
D'Negri, Carlos E; Marelich, Liliana; Vigo, Daniel; Acunzo, Rafael S; Girotti, Luis A; Cardinali, Daniel P; Siri, Leonardo Nicola
1. For the heartrate in Pterotrachea coronata, intermediate temperatures disclose a thermal increment of 11,200 ±. This value is identical with the one reported by Crozier and Stier for the lamelli-branch, Anodonta. In the pteropod, Tiedemannia neapolitana the same temperatures typically reveal in the heartrate a µ value of 16,200 ± This agrees quantitatively with 16,300 found by Crozier and Stier for the heart of the slug, Limax maximus. 2. At high temperatures the average value of µ for Pterotrachea is 7,300: for Tiedemannia, 7,400. The corresponding averages at the lower limits are 22,000 and 23,000. 3. The great variability found near the edges of the temperature field are explicable in two ways. During intermissions characteristic of high temperatures and occurring also at low, we can assume a restorative process; while at both the upper and lower limits we may, in addition, find that reactions assume control which under ordinary circumstances never do so. Special evidence indicates that the highest temperatures employed, 27°C., and the lowest, 4°C., caused no irreversible changes in mechanism. 4. The theoretical analysis of the experimental facts makes use of Meyerhof's conception of carbohydrate metabolism and projects the cyclical nature of rhythm into the substrate of control. Assuming as a source of energy an original supply of material O, the value of 22,000 ± is assigned provisionally to a mobilization hydrolysis while 11,200 ± and 16,000 ± are attached to oxidative reactions influenced respectively by OH' and possibly Fe, or some other catalyst. The lowest value, 7,300 ± is assumed to indicate a synthetic process (lactic acid ? glycogen?), possibly limited by CO2 excretion. In the present state of our knowledge, this distribution and interpretation seems to account reasonably for the experimental facts, but until we know more about the neurogenic controls, is entitled to rank only as an hypothesis. PMID:19872250
1. For the heartrate in Pterotrachea coronata, intermediate temperatures disclose a thermal increment of 11,200 +/-. This value is identical with the one reported by Crozier and Stier for the lamelli-branch, Anodonta. In the pteropod, Tiedemannia neapolitana the same temperatures typically reveal in the heartrate a micro value of 16,200 +/- This agrees quantitatively with 16,300 found by Crozier and Stier for the heart of the slug, Limax maximus. 2. At high temperatures the average value of micro for Pterotrachea is 7,300: for Tiedemannia, 7,400. The corresponding averages at the lower limits are 22,000 and 23,000. 3. The great variability found near the edges of the temperature field are explicable in two ways. During intermissions characteristic of high temperatures and occurring also at low, we can assume a restorative process; while at both the upper and lower limits we may, in addition, find that reactions assume control which under ordinary circumstances never do so. Special evidence indicates that the highest temperatures employed, 27 degrees C., and the lowest, 4 degrees C., caused no irreversible changes in mechanism. 4. The theoretical analysis of the experimental facts makes use of Meyerhof's conception of carbohydrate metabolism and projects the cyclical nature of rhythm into the substrate of control. Assuming as a source of energy an original supply of material O, the value of 22,000 +/- is assigned provisionally to a mobilization hydrolysis while 11,200 +/- and 16,000 +/- are attached to oxidative reactions influenced respectively by OH' and possibly Fe, or some other catalyst. The lowest value, 7,300 +/- is assumed to indicate a synthetic process (lactic acid --> glycogen?), possibly limited by CO(2) excretion. In the present state of our knowledge, this distribution and interpretation seems to account reasonably for the experimental facts, but until we know more about the neurogenic controls, is entitled to rank only as an hypothesis. PMID:19872250
Muskrats (Ondontra zibethicus) are common freshwater diving mammals exhibiting a bradycardia with both forced and voluntary diving. This bradycardia is mediated by vagal innervation; however, if hypoxia is present there may be local factors that also decrease heartrate. Some of these local factors may include ATP-sensitive potassium channel activation and extracellular accumulation of potassium ions, hydrogen ions and lactate. The purpose of this study was to investigate the role of these factors in the isolated perfused hearts of muskrats and of a non-diving mammal, the guinea pig. Although lactate and proton administration reduced heartrate in isolated muskrat and guinea pig hearts, there was no difference in the response to lactate and proton infusion between the two species. Muskrat hearts were more sensitive to the heart-rate-lowering effects of exogenously applied potassium than were guinea pig hearts. Early increases in extracellular potassium concentration during hypoxia are thought to be mediated by the ATP-sensitive potassium channel. Activation of these channels under normoxic conditions had a mildly negative chronotropic effect in both species; however, activation of these channels with Lemakalim under hypoxic conditions caused the guinea pig heart to respond with an augmented bradycardia similar to that seen in the hypoxic muskrat heart in the absence of drugs. Inhibition of these channels by glibenclamide during hypoxia was partially successful in blocking the bradycardia in guinea pig hearts, but inhibition of the same channels in hypoxic muskrat hearts had a damaging effect as two of five hearts went into contracture during the hypoxia. Thus, although ATP-sensitive potassium channels appear to have a major role in the bradycardia of hypoxia in guinea pigs, the failure to prevent the bradycardia by inhibition of these channels in muskrat hearts suggests that multiple factors are involved in the hypoxia-induced bradycardia in this species. PMID:7852900
The authors, using a crossover design, randomly administered, in a single-blind manner, 3 primary intraosseous injections to 61 subjects using: the Wand local anesthetic system at a deposition rate of 45 seconds (fast injection); the Wand local anesthetic system at a deposition rate of 4 minutes and 45 seconds (slow injection); a conventional syringe injection at a deposition rate of 4 minutes and 45 seconds (slow injection), in 3 separate appointments spaced at least 3 weeks apart. A pulse oximeter measured heartrate (pulse). The results demonstrated the mean maximum heartrate was statistically higher with the fast intraosseous injection (average 21 to 28 beats/min increase) than either of the 2 slow intraosseous injections (average 10 to 12 beats/min increase). There was no statistically significant difference between the 2 slow injections. We concluded that an intraosseous injection of 1.4 mL of 2% lidocaine with 1?:?100,000 epinephrine with the Wand at a 45-second rate of anesthetic deposition resulted in a significantly higher heartrate when compared with a 4-minute and 45-second anesthetic solution deposition using either the Wand or traditional syringe. PMID:18327970
OBJECTIVE: To gather current information about the effects of type 1 diabetes mellitus on children's cardiac autonomic behavior. DATA SOURCES: The search of articles was conducted on PubMed, Ibecs, Medline, Cochrane, Lilacs, SciELO and PEDro databases using the MeSH terms: "autonomic nervous system", "diabetes mellitus", "child", "type 1 diabetes mellitus", "sympathetic nervous system" and "parasympathetic nervous system", and their respective versions in Portuguese (DeCS). Articles published from January 2003 to February 2013 that enrolled children with 9-12 years old with type 1 diabetes mellitus were included in the review. DATA SYNTHESIS: The electronic search resulted in four articles that approached the heartrate variability in children with type 1 diabetes mellitus, showing that, in general, these children present decreased global heartrate variability and vagal activity. The practice of physical activity promoted benefits for these individuals. CONCLUSIONS: Children with type 1 diabetes mellitus present changes on autonomic modulation, indicating the need for early attention to avoid future complications in this group. PMID:25119762
Gardim, Camila Balsamo; de Oliveira, Bruno Affonso P.; Bernardo, Aline Fernanda B.; Gomes, Rayana Loch; Pacagnelli, Francis Lopes; Lorenconi, Roselene Modolo R.; Vanderlei, Luiz Carlos M.
Ultrasound fetal heartrate monitoring is very useful to determine the status of the fetus because it is noninvasive. In order to ensure the accuracy of the fetal heartrate (FHR) obtained from the ultrasound Doppler data, we measure the fetal electrocardiogram (ECG) directly and obtain the Doppler data simultaneously. The FHR differences of the Doppler data from the direct ECG data are concentrated at 0 bpm (beats per minute), and are practically symmetrical. The distribution is found to be very close to the Student's t distribution by the test of goodness of fit with the chi-square test. The spectral density of the FHR differences shows the white noise spectrum without any dominant peaks. Furthermore, the f-n (n>1) fluctuation is observed both with the ultrasound Doppler FHR and with the direct ECG FHR. Thus, it is confirmed that the FHR observation and observation of the f-n (n>1) fluctuation using the ultrasound Doppler FHR are as useful as the direct ECG.
The aim of this study was to test the utility of heart-rate variability (HRV) analyses as a noninvasive means of quantifying cardiac autonomic regulation during precompetitive anxiety situations in swimmers. Psychophysiological state evaluation of 10 volunteer swimmers (6 women and 4 men) was obtained by comparing baseline training condition (TC) with competition condition (CC). Self-evaluation of precompetitive somatic anxiety measured by CSAI-2 showed significant increase from the TC to CC. Analysis showed that during higher precompetitive anxiety level, a significant reduction in the timing (RMSSD), frequency (HFms2 and HFnu) and Poincaré plot (SD1) of heart-rate variability was observed, and a significant increase in the low frequency to high frequency ratio (LF/HF %). The results indicate a shift towards sympathetic predominance as a result of parasympathetic withdrawal. Our results provide an HRV analysis in a valid, useful and non-invasive way to evaluate the change of sympathovagal balance in presence of precompetitive stress. PMID:19861094
Cervantes Blásquez, Julio César; Rodas Font, Gil; Capdevila Ortís, Lluís
Cardiovascular complications are the most common causes of morbidity and mortality in acromegaly. However, there is little data regarding cardiac autonomic functions in these patients. Herein, we aimed to investigate several parameters of cardiac autonomic functions in patients with acromegaly compared to healthy subjects. We enrolled 20 newly diagnosed acromegalic patients (55% female, age:45.7 ± 12.6 years) and 32 age- and gender-matched healthy subjects. All participants underwent 24 h Holter recording. Heartrate recovery (HRR) indices were calculated by subtracting 1st, 2nd and 3rd minute heartrates from maximal heartrate. All patients underwent heartrate variability (HRV) and QT dynamicity analysis. Baseline characteristics were similar except diabetes mellitus and hypertension among groups. Mean HRR1 (29.2 ± 12.3 vs 42.6 ± 6.5, p = 0.001), HRR2 (43.5 ± 15.6 vs 61.1 ± 10.8, p = 0.001) and HRR3 (46.4 ± 16.2 vs 65.8 ± 9.8, p = 0.001) values were significantly higher in control group. HRV parameters as, SDNN [standard deviation of all NN intervals] (p = 0.001), SDANN [SD of the 5 min mean RR intervals] (p = 0.001), RMSSD [root square of successive differences in RR interval] (p = 0.001), PNN50 [proportion of differences in successive NN intervals >50 ms] (p = 0.001) and high-frequency [HF] (p = 0.001) were significantly decreased in patients with acromegaly; but low frequency [LF] (p = 0.046) and LF/HF (p = 0.001) were significantly higher in acromegaly patients. QTec (p = 0.009), QTac/RR slope (p = 0.017) and QTec/RR slope (p = 0.01) were significantly higher in patients with acromegaly. Additionally, there were significant negative correlation of disease duration with HRR2, HRR3, SDNN, PNN50, RMSSD, variability index. Our study results suggest that cardiac autonomic functions are impaired in patients with acromegaly. Further large scale studies are needed to exhibit the prognostic significance of impaired autonomic functions in patients with acromegaly. PMID:23553172
is under control of the autonomic nervous system has promoted the analysis of heartrate variation: mathematical modeling, infection, humans, inflammation, autonomic nervous system, heart #12;4 Introduction1 Title: A Physiological Model for Autonomic HeartRate Regulation in Human Endotoxemia Authors
of the nervous system increases the heart rhythm, resulting in shorter beat intervals. The parasympathetic branchDevelopment of a Matlab Software for Analysis of HeartRate Variability JoÃ£o Luiz Azevedo de, Brazil, 70510-900 e-mail: firstname.lastname@example.org Abstract--The analysis of heartrate variability (HRV) signals
The control of human heartrate during exercise is an important problem that has implications for the development of protocols for athletics, assessing physical fitness, weight management, and the prevention of heart failure. Here we provide a new stabilization technique for a recently-proposed nonlinear model for human heartrate response that describes the central and peripheral local responses during and
Frédéric Mazenc; Michael Malisoff; Marcio de Querioz
Crandall, C. G., R. Zhang, and B. D. Levine. Effects of whole body heating on dynamic baroreflex regulation of heartrate in humans. Am J Physiol Heart Circ Physiol 279: H2486-H2492, 2000.The purpose of this project was to identify whether dynamic baroreflex regulation of heartrate (HR) is altered during whole body heating. In 14 subjects, dynamic baroreflex regulation of
BackgroundSympathetic traffic to the peripheral vasculature and sympathetic discharge to the heart have complemen- tary effects on blood pressure. Although faster heartrates have been linked to higher blood pressures, the relationship between muscle sympathetic nerve activity (MSNA) and long-term regulation of blood pressure is not clear. We tested the hypothesis that MSNA and heartrate are linked to blood
It has been shown that the fractal scaling properties of heartrate dynamics, in healthy aging, differ from that seen in heart disease and this favors the use of fluctuation measures as diagnostic tools. The purpose of this study was to evaluate the fractal heartrate dynamics in adults with Down syndrome (DS) under different physiological conditions (rest, exercise and
Goncalo V. Mendonca; Fernando D. Pereira; Bo Fernhall
Objectives: This is an observational study aimed to investigate the activity of autonomic nervous system during sleep in patients with sleep-related migraine. Methods: Eight consecutive migraineurs without aura were enrolled (6 women and 2 men), aged 30 to 62 years (mean 48.1 ± 9.3 years). Inclusion criteria were: high frequency of attacks (> 5 per month) and occurrence of more than 75% of the attacks during sleep causing an awakening. Patients were compared with a control group of 55 healthy subjects (23 men and 32 women, mean age 54.2 ± 13.0 years), and with a further control group of 8 age- and gender-matched healthy controls. Patient and controls underwent polysomnography and heartrate variability analysis. Results: A significant reduction of the LF/HF ratio during N2 and N3 sleep stages was observed in migraineurs compared with controls. No differences in sleep macrostructure were observed; cyclic alternating pattern (CAP) time and CAP rate were lower in migraineurs than in controls. Conclusions: These findings indicate a peculiar modification of the autonomic balance during sleep in sleep-related migraine. The reduction of LF/HF ratio in NREM sleep was observed in controls, but it was quantitatively much more evident in migraineurs. Changes in LF/HF could be consequent to an autonomic unbalance which could manifest selectively (or alternatively become more evident) during sleep. These findings, together with the reduction in CAP rate, could be an expression of reduced arousability during sleep in patients with sleep-related migraine. The simultaneous involvement of the autonomic, arousal, and pain systems might suggest involvement of the hypothalamic pathways. Citation: Vollono C; Gnoni V; Testani E; Dittoni S; Losurdo A; Colicchio S; Di Blasi C; Mazza S; Farina B; Della Marca G. Heartrate variability in sleep-related migraine without aura. J Clin Sleep Med 2013;9(7):707-714. PMID:23853566
We propose equivalent heartrate (eHR) as an estimate of the frequency of contractions of individual myocytes in a fibrillating ventricle by analyzing mechanics and energetics of the ventricle. Using the isolated, cross-circulated dog heart preparation, we determined eHR in two different ways. First, we obtained eHR (eHR1) from myocardial O2 consumption (Vo2)-equivalent pressure-volume area (ePVA) data points during ventricular fibrillation (VF) by utilizing the Vo2-pressure-volume area (PVA) relation in the beating state. PVA is the area surrounded by the end-systolic and end-diastolic pressure-volume relations and the systolic pressure-volume trajectory in the pressure-volume diagram. PVA has been shown to represent the total mechanical energy generated by each contraction. We have recently proposed ePVA as a measure of the total mechanical energy generated by single contractions of all individual asynchronously contracting myocytes in a fibrillating ventricle. ePVA is the area surrounded by the horizontal line at the VF pressure and the end-systolic and end-diastolic pressure-volume relations in the beating state. Second, we measured Vo2 in beating state at various heartrates and Vo2 during VF under a mechanically unloaded condition. By comparing these fibrillating and beating Vo2 values, we determined eHR (eHR2) for the fibrillating state. eHR1 was 216 +/- 27 beats/min and eHR2 was 223 +/- 26 beats/min. These two values were not significantly different. We conclude that the average frequency of contractions of individual myocytes in a fibrillating ventricle is equivalent approximately to 220 beats/min in terms of ventricular energetics. PMID:1806676
Aims: The quantification of mechanical dyssynchrony has important diagnostic value and may help to determine optimal therapy in heart failure (HF). We hypothesized that mechanical dyssynchrony may be augmented at increased heartrates in patients with HF and normal QRS duration. Methods and results: From online segmental conductance catheter signals, we derived indices to quantify temporal and spatial aspects of
Summary Objective: Vital exhaustion and type D personality previously predicted mortality and cardiac events in patients with chronic heart failure (CHF). Reduced heartrate recovery (HRR) also predicts morbidity and mortality in CHF. We hypothesized that elevated levels of vital exhaustion and type D personality are both associated with decreased HRR. Methods: Fifty-one patients with CHF (mean age 58 ±
Roland von Känel; Jürgen Barth; Sonja Kohls; Hugo Saner; Hansjörg Znoj; Gaby Saner; Jean-Paul Schmid
Heartrate signal can be used as certain indicator of heart disease. Spectral analysis of heartrate variability (HRV) signal\\u000a makes it possible to partly separate the low-frequency (LF) sympathetic component, from the high-frequency (HF) vagal component\\u000a of autonomic cardiac control. Here, we used two important features to characterize the nonlinear fluctuations in the heart\\u000a variability signal (HRV): cardiac vagal
Measurements of exercise heartrate (HRex), HR recovery (HRR) and HR variability (HRV) are used as indices of training status. However, the day-to-day variability\\u000a of these indices throughout a competitive soccer period is unknown. On 14 occasions during a 3-week competition camp, 18 under\\u000a 15 (U15) and 15 under 17 (U17) years soccer players performed a 5-min submaximal run, followed
Martin Buchheit; Alberto Mendez-Villanueva; Marc J. Quod; Nicholas Poulos; Pitre Bourdon
The present work focuses on whether the heartrate variability (HRV) evaluated during the cold stress is different from that\\u000a in the control condition. In fifteen subjects (12M & 3F, aging 2124 yrs), a fiveminute ECG record was performed in the room\\u000a temperature condition (27°C), and the other fiveminute ECG record was then measured in the cold stress during which
To examine the orthostatic influence on heartrate and blood pressure variability in persons with tetraplegia playing wheelchair\\u000a basketball, ten trained persons with tetraplegia, ten untrained persons with tetraplegia, and ten able-bodied participated\\u000a in this study. Spectrum analysis of the ECG RR interval and blood-pressure on a beat-by-beat basis during head-up tilt 60°\\u000a sitting were performed. The ratio of the
\\u000a Twenty healthy women aged between 65 and 74 years, trained three times a week, for 16 weeks, on a cycle ergometer, to determine\\u000a the effects of dynamic resistance training on heartrate variability (HRV). Subjects were allocated to two training groups,\\u000a high (HI, n=10) and low (LO, n=10) intensity. The HI group performed eight sets of 8 revolutions at 80% of the
The aim of the study was to evaluate the effectiveness of the Poincaré plot analysis of heartrate variability (HRV) in observing endurance training-induced changes. Four 10-min manoeuvres were performed (supine lying, standing, steady state exercising and subsequent recovery) by eight control subjects before and after a short-term endurance training and by eight subjects trained for at least 3 years. HRV
Laurent Mourot; Malika Bouhaddi; Stéphane Perrey; Jean-Denis Rouillon; Jacques Regnard
There is limited data on heartrate turbulence (HRT) in systemic sclerosis (SSc) patients, potentially threatened with cardiac autonomic dysfunction. We performed 24-hour Holter monitoring for HRT assessment in 45 patients with SSc and 30 healthy controls. Abnormal HRT defined as turbulence onset (TO) ?0.0% and\\/or turbulence slope (TS)?2.5 ms\\/RR was found in 19 (42%) of SSc patients while not in
Piotr Bienias; Micha? Ciurzy?ski; Dariusz Korczak; Krzysztof Jankowski; Maria Gli?ska-Wielochowska; Danuta Liszewska-Pfejfer; Wies?aw Gli?ski; Piotr Pruszczyk
It has been proposed that cardiac control is altered in the elderly. Power spectral analysis of heartrate variability (HRV)\\u000a was performed on 12 male and 11 female elderly subjects (mean age 74?years) while at rest in supine and sitting positions,\\u000a and at steady states during 5?min of exercise (3595% peak oxygen consumption, V?O2peak). There were no differences in power,
Renza Perini; Stefania Milesi; Nadine M. Fisher; David R. Pendergast; Arsenio Veicsteinas
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 HeartRate 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.
The heartrate 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 (<40 interbeat intervals) and the decrease of the scaling exponent at longer scales (40-512 interbeat intervals). In certain cases, the scaling exponent during relaxing visualization indicates the breakdown of long-range correlations. These characteristics have been previously seen in the HRV dynamics during non-REM sleep.
The mechanism of human thermal comfort is important for building a comfortable and healthy indoor environment. This paper analyzes human heartrate variability (HRV) at different thermal comfort levels and discusses the mechanism of human thermal comfort. A total of 33 subjects were divided in 3 groups. Under air temperatures of 21, 24, 26, 28, 29, and 30 degrees C, the subjects' electrocardiogram was recorded for 5 min. HRV (the ratio of absolute powers in low- and high-frequency bands, LF/HF ratio) was analyzed. LF/HF at discomfort level were significantly higher than that at comfort level (P < 0.05), despite the same thermal sensation. The results indicate that sympathetic activity plays an important role in subjects' thermal discomfort and the LF/HF ratio may be used as an indicator for human thermal comfort. PMID:18351379
The goal of the study was to determine the effect of a 1-h hour long forklift truck virtual simulator driving on the mechanism of autonomic heartrate (HR) regulation in operators. The participants were divided into 2 subgroups: subjects with no definite inclination to motion sickness (group A) and subjects with a definite inclination to motion sickness (group B). Holter monitoring of electrocardiogram (ECG) signal was carried out in all subjects during the virtual simulator driving. For 12 consecutive epochs of ECG signal, HR variability analysis was conducted in time and frequency domains. In subjects with a definite inclination to motion sickness after ~30 min of the driving, changes in parameter values were found indicating an increase in sympathetic and parasympathetic activity with parasympathetic dominance. PMID:22152505
Zu?ewicz, Krystyna; Saulewicz, Antoni; Konarska, Maria; Kaczorowski, Zbigniew
This study examined the effects of prenatal visual stimulation on bobwhite quail embryos' growth and heartrate. No differences in growth rate were found between embryos exposed to visual stimulation during the late prenatal period and control embryos. Embryos exposed to visual stimulation throughout incubation maintained lower heartrates in response to visual stimulation than did naïve embryos. In a subsequent experiment, naïve embryos that underwent an egg-opening procedure exhibited heartrates that were lower than embryos measured in intact eggshells. Embryos in opened eggs maintained lower heartrates than comparison embryos across time; however, a less invasive egg-opening procedure led to a quicker heartrate recovery than did a more invasive egg-opening procedure. These findings indicate that prenatal heartrate responses may be mediated by multiple features of the organism's developmental context, including intensity and duration of sensory stimulation. PMID:16617467
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 (heartrate) 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 heartrate (HR) using telemetric devices, while the physical profile was evaluated by recording motion and speed by means of GPS devices. During competitive matches, players obtained a HRmean of 165.2 bpm (86.5% HRmax), with 59.3% of the time participating (TP) corresponding to values above 90% of the HRmax. The distance covered per minute of participation was 97.7 m, with 9.5% of this distance corresponding to high-intensity running and 2.5% to sprint; the work:rest ratio was 1.4:1 and the maximum speed 21.7 km·h-1. These results showed that beach soccer is an intermittent physical activity of greater intensity than other team games. It requires a major contribution from the anaerobic system as emphasis is placed on players making quick bursts of high-intensity activity separated by brief rest periods. Key points The distance covered per minute of play is around 100 m. Beach soccer is an intermittent sport with a work:rest ratio of 1.4:1. The playing surface in beach soccer is an important handicap to obtain maximum speeds. Beach soccer has a high physiological intensity, with more than half of the game is spent at intensities above 90 % of the HRmax. PMID:24149392
The effects of acoustic and visual stimuli and their synergistic effects on heartrate variability including gender differences were investigated. Of particular interest was the influence of visual stimulus on heartrate variability during listening to simple sounds of different characters. Twelve male and 12 female university students were selected as subjects. The subjects listened at rest to 7 different figures of sound at loudness levels averaging 60 dB. Beat-to-beat R-R intervals were continuously recorded under the closed-eye condition (CEC) and the open-eye condition (OEC) prior to, during, and immediately after the exposure to acoustic stimuli. Low frequency (LF) power was defined over 0.04-0.15 Hz and high frequency (HF) power over 0.15-0.40 Hz. Cardiac autonomic function was estimated by plotting LF/HF in standard measure against HF in standard measure and by plotting LF/HF (%) against HF (%), accompanied by a demarcated central area. Values of LF/HF tended to be smaller under CEC than under OEC. Values of HF while listening to a 110 Hz sine wave under CEC were significantly greater than values for 880 Hz and 3520 Hz sine waves, or for 110 Hz or 880 Hz sawtooth waves, under OEC. Under CEC, values of HF for 7 figures of sound were greater in females than in males. The value of HF of sine wave for 110 Hz under CEC and OEC was significantly greater than that for white noise under the OEC. The results suggest that the cardiac parasympathetic nervous activity during auditory excitation increases with elimination of visual stimuli and tends to be greater in females than in males. PMID:17393762
Hori, Kiyokazu; Yamakawa, Masanobu; Tanaka, Nobuo; Murakami, Hiromi; Kaya, Mitsuharu; Hori, Seiki
Study Objectives: The visual appearance of cortical arousals varies considerably, from barely meeting scoring criteria to very intense arousals. Arousal from sleep is associated with an increase in heartrate (HR). Our objective was to quantify the intensity of arousals in an objective manner using the time and frequency characteristics of the electroencephalogram (EEG) and to determine whether HR response to arousal correlates with arousal intensity so determined. Design: Post hoc analysis of 20 preexisting polysomnography (PSG) files. Setting: Research and Development Laboratory (YRT Limited). Participants: N/A. Interventions: None. Measurements and Results: Arousals were scored using the American Academy of Sleep Medicine criteria. The EEG signals' time and frequency characteristics were determined using wavelet analysis. An automatic algorithm was developed to scale arousal intensity based on the change in wavelet features and data from a training set obtained from 271 arousals visually scaled between zero and nine (most intense). There were 2,695 arousals in 20 PSGs that were scaled. HR response (?HR) was defined as the difference between the highest HR in the interval [arousal-onset to (arousal-end +8 sec)] and the highest HR between 2 and 12 sec preceding arousal onset. There was a strong correlation between arousal scale and ?HR within each subject (average r: 0.95 ± 0.04). The slope of the relationship varied among subjects (0.7-2.4 min-1/unit scale). Conclusions: Arousal intensity, quantified by wavelet transform, is strongly associated with arousal-related tachycardia, and the gain of the relationship varies among subjects. Quantifying arousal intensity in PSGs provides additional information that may be clinically relevant. Citation: Azarbarzin A; Ostrowski M; Hanly P; Younes M. Relationship between arousal intensity and heartrate response to arousal. SLEEP 2014;37(4):645-653. PMID:24899756
Recovery in heartrate (HR) after exercise is a measure of autonomic function and a prognostic indicator in cardiovascular disease. The aim of this study was to characterize heartrate recovery (HRR) and to determine its relation to cardiac function and morphology in patients with hypertrophic cardiomyopathy (HC). We studied 18 healthy volunteers and 41 individuals with HC. All patients underwent clinical assessment and transthoracic echocardiography. Continuous beat-by-beat assessment of HR was obtained during and after cardiopulmonary exercise testing using finger plethysmography. HRR and power spectral densities were calculated on 3 minutes of continuous RR recordings. Absolute HRR was lower in patients than that in controls at 1, 2, and 3 minutes (25.7 ± 8.4 vs 35.3 ± 11.0 beats/min, p <0.001; 36.8 ± 9.4 vs 53.6 ± 13.2 beats/min, p <0.001; 41.2 ± 12.2 vs 62.1 ± 14.5 beats/min, p <0.001, respectively). HRR remained lower in patients at 2 and 3 minutes after normalization to peak HR. After normalization to the difference in HR between peak exercise and rest, HRR was significantly impaired in individuals with obstructive HC at 3 minutes compared with controls. HR at 3 minutes correlated with peak left ventricular outflow tract gradient (B 0.154 beats/min/mm Hg, confidence interval 0.010 to 0.299, p = 0.037) and remained a significa