Sample records for heart rate performance

  1. Attentional Focus and Performance Anxiety: Effects on Simulated Race-Driving Performance and Heart Rate Variability

    PubMed Central

    Mullen, Richard; Faull, Andrea; Jones, Eleri S.; Kingston, Kieran

    2012-01-01

    Previous studies have demonstrated that an external focus can enhance motor learning compared to an internal focus. The benefits of adopting an external focus are attributed to the use of less effortful automatic control processes, while an internal focus relies upon more effort-intensive consciously controlled processes. The aim of this study was to compare the effectiveness of a distal external focus with an internal focus in the acquisition of a simulated driving task and subsequent performance in a competitive condition designed to increase state anxiety. To provide further evidence for the automatic nature of externally controlled movements, the study included heart rate variability (HRV) as an index of mental effort. Sixteen participants completed eight blocks of four laps in either a distal external or internal focus condition, followed by two blocks of four laps in the competitive condition. During acquisition, the performance of both groups improved; however, the distal external focus group outperformed the internal focus group. The poorer performance of the internal focus group was accompanied by a larger reduction in HRV, indicating a greater investment of mental effort. In the competition condition, state anxiety increased, and for both groups, performance improved as a function of the increased anxiety. Increased heart rate and self-reported mental effort accompanied the performance improvement. The distal external focus group also outperformed the internal focus group across both neutral and competitive conditions and this more effective performance was again associated with lower levels of HRV. Overall, the results offer support for the suggestion that an external focus promotes a more automatic mode of functioning. In the competitive condition, both foci enhanced performance and while the improved performance may have been achieved at the expense of greater compensatory mental effort, this was not reflected in HRV scores. PMID:23133431

  2. Heart Rate and Exercise

    NSDL National Science Digital Library

    Barbara Z. Tharp

    2009-01-01

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

  3. Effects of relative metabolic rate and heart rate variation on the performance of flight attendants.

    PubMed

    Yoshioka, T; Narusawa, M; Nagami, K; Yabuki, C; Nakahara, Y; Nakano, S; Sekiguchi, C; Noda, K; Nagai, T; Kobayashi, Y; Kobayashi, K; Ohmori, K; Sakai, T; Furusato, M

    1982-02-01

    The main work of the cabin attendants in an actual flight in service for passengers. The effects of flight attendant duties in flight differ from the effects of the same tasks performed on the ground. In this study, the relative metabolic rate (RMR) and heart rate (HR) of cabin attendants in a cruising aircraft galley and cabin are compared with those of a crew working in a mock-up apparatus on the ground. The types of work tested are: (a) oshibori (steamed towel) service, (b) soft drink service, (c) setting meal tray, (d) putting casserole on tray, (e) meal tray service, (f) walking on aisle. The RMR at each type of work during flight is as indicated: (a) 1.07-2.10, (b) 1.08-1.54, (c) 1.37-1.82, (d) 2.57-3.50, (e) 2.11-3.10 and (f) 1.84. The range of HR was: (a) 105-120, (b) 90-110, (c) 90-120, (d) 100-130 and 100-140 beats/min. In most cases, the RMR and HR levels of work done in the mock-up were lower than those recorded in flight. These results suggest that the oxygen intake of work done in flight is greater than that on a mock-up. One of the reasons might be that the cabin barometric pressure (ca. 660 torr or cabin altitude ca. 1,500 m) or an aisle inclination of about 3 degrees caused a decrease in the efficiency of oxygen intake during flight. PMID:7059328

  4. Heart rate, anxiety and performance of residents during a simulated critical clinical encounter: a pilot study

    PubMed Central

    2014-01-01

    Background High-fidelity patient simulation has been praised for its ability to recreate lifelike training conditions. The degree to which high fidelity simulation elicits acute emotional and physiologic stress among participants – and the influence of acute stress on clinical performance in the simulation setting – remain areas of active exploration. We examined the relationship between residents’ self-reported anxiety and a proxy of physiologic stress (heart rate) as well as their clinical performance in a simulation exam using a validated assessment of non-technical skills, the Ottawa Crisis Resource Management Global Rating Scale (Ottawa GRS). Methods This was a prospective observational cohort study of emergency medicine residents at a single academic center. Participants managed a simulated clinical encounter. Anxiety was assessed using a pre- and post-simulation survey, and continuous cardiac monitoring was performed on each participant during the scenario. Performance in the simulation scenario was graded by faculty raters using a critical actions checklist and the Ottawa GRS instrument. Results Data collection occurred during the 2011 academic year. Of 40 eligible residents, 34 were included in the analysis. The median baseline heart rate for participants was 70 beats per minute (IQR: 62 – 78). During the simulation, the median maximum heart rate was 140 beats per minute (IQR: 137 – 151). The median minimum heart rate during simulation was 81 beats per minute (IQR: 72 – 92), and mean heart rate was 117 beats per minute (95% CI: 111 – 123). Pre- and post-simulation anxiety scores were equal (mean 3.3, IQR: 3 to 4). The minimum and maximum Overall Ottawa GRS scores were 2.33 and 6.67, respectively. The median Overall score was 5.63 (IQR: 5.0 to 6.0). Of the candidate predictors of Overall performance in a multivariate logistic regression model, only PGY status showed statistical significance (P?=?0.02). Conclusions Simulation is associated with physiologic stress, and heart rate elevation alone correlates poorly with both perceived stress and performance. Non-technical performance in the simulation setting may be more closely tied to one’s level of clinical experience than to perceived or actual stress. PMID:25064689

  5. Target Heart Rate

    NSDL National Science Digital Library

    Mr. Peterson

    2011-09-18

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

  6. Heart Rate Monitors

    NASA Technical Reports Server (NTRS)

    1990-01-01

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

  7. The effect of heart rate variability biofeedback on performance psychology of basketball players.

    PubMed

    Paul, Maman; Garg, Kanupriya

    2012-06-01

    Coping with pressure and anxiety is an ineluctable demand of sports performance. Heart rate variability (HRV) Biofeedback (BFB) shall be used as a tool for self regulating physiological responses resulting in improved psycho physiological interactions. For further analysis, the present study has been designed to examine the relationship between anxiety and performance and also effectiveness of biofeedback protocol to create stress-eliciting situation in basketball players. Thirty basketball players of university level and above (both male and female) aged 18-28 years, who scored a minimum of 20 in state trait anxiety inventory, were randomly divided into three equal groups- Experimental (Biofeedback) group, Placebo group and Control (No Treatment) group. The BFB group received HRV BFB training for 10 consecutive days for 20 min that included breathing at individual's resonant frequency through a pacing stimulus; Placebo group was shown motivational video clips for 10 consecutive days for 10 min, whereas No Treatment Control group was not given any intervention. Two way repeated measure ANOVA was applied to analyze the differences within and between the groups. Anxiety, coping self-efficacy, heart rate variability, respiration rate, and performance (dribbling, passing and shooting) at session 1, 10 and 1 month follow up were statistically significant in each group along with interaction of group and time (p < 0.001). Also, all the measures showed statistically significant inter group difference (p < 0.05). The findings are harmonious with existing data on HRV BFB as a strategy for dealing with anxiety. The Placebo group showed improvement in self efficacy and performance post training. The Control group showed no change in any variable except performance. The results of the study support the idea that HRV BFB lowers the anxiety and thus there seems to be a potential association between HRV BFB and performance optimization. PMID:22402913

  8. Effect of water temperature on performance, lactate production and heart rate at swimming of maximal and submaximal intensity.

    PubMed

    Mougios, V; Deligiannis, A

    1993-03-01

    The effect of water temperature on performance effort, monitored heart rate and lactate production during freestyle swimming at maximal and submaximal speed has been studied. Fifteen male sprint swimmers performing 100 m swimming and fifteen comparable endurance competitors performing 30 min swimming at submaximal speed served as subjects. Water temperature in separate events was 20, 26 and 32 degrees C. At maximal performance there was a direct relationship between any two of the following parameters: water temperature, average swimming speed, heart rate during the competition and plasma lactate concentration after the event. Thus, the best effort (speed 1.704 m/s), the highest peak heart rate (185 beats/min) and the highest lactate level (19.8 mmol/l) were observed at 32 degrees C (all mean values). In contrast, these values were markedly lower at 20 degrees C. At the submaximal effort, water temperature was related to peak heart rate only. The highest peak heart rate (144 beats/min) was again obtained at 32 degrees C, while the lactate concentration (4.2-5.2 mmol/l) was independent of temperature. Water temperature appears to have a direct effect on performance effort, heart rate and lactate production during swimming at maximal intensity, whereas this effect seems to fade at submaximal efforts. PMID:8350604

  9. RELATIONSHIPS BETWEEN HEART RATE AND PHYSIOLOGICAL PARAMETERS OF PERFORMANCE IN TOP-LEVEL WATER POLO PLAYERS

    PubMed Central

    Ben Zoubir, S.; Hambli, M.; Chaouachi, A.; Hue, O.; Chamari, K.

    2014-01-01

    The aim of this study was to measure the heart rate (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 (V.O2max, Th1vent, Th2vent). Each athlete performed a V.O2max treadmill test and played a water polo game wearing a heart rate 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 V.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 V.O2max and that HR monitoring could be of great interest in the control of water polo training sessions. PMID:24917687

  10. The Effects of Guided Imagery on Heart Rate Variability in Simulated Spaceflight Emergency Tasks Performers

    PubMed Central

    Yijing, Zhang; Xiaoping, Du; Fang, Liu; Xiaolu, Jing; Bin, Wu

    2015-01-01

    Objectives. The present study aimed to investigate the effects of guided imagery training on heart rate variability in individuals while performing spaceflight emergency tasks. Materials and Methods. Twenty-one student subjects were recruited for the experiment and randomly divided into two groups: imagery group (n = 11) and control group (n = 10). The imagery group received instructor-guided imagery (session 1) and self-guided imagery training (session 2) consecutively, while the control group only received conventional training. Electrocardiograms of the subjects were recorded during their performance of nine spaceflight emergency tasks after imagery training. Results. In both of the sessions, the root mean square of successive differences (RMSSD), the standard deviation of all normal NN (SDNN), the proportion of NN50 divided by the total number of NNs (PNN50), the very low frequency (VLF), the low frequency (LF), the high frequency (HF), and the total power (TP) in the imagery group were significantly higher than those in the control group. Moreover, LF/HF of the subjects after instructor-guided imagery training was lower than that after self-guided imagery training. Conclusions. Guided imagery was an effective regulator for HRV indices and could be a potential stress countermeasure in performing spaceflight tasks. PMID:26137491

  11. Spectral analyses of systolic blood pressure and heart rate variability and their association with cognitive performance in elderly hypertensive subjects.

    PubMed

    Santos, W B; Matoso, J M D; Maltez, M; Gonçalves, T; Casanova, M; Moreira, I F H; Lourenço, R A; Monteiro, W D; Farinatti, P T V; Soares, P P; Oigman, W; Neves, M F T; Correia, M L G

    2015-08-01

    Systolic hypertension is associated with cognitive decline in the elderly. Altered blood pressure (BP) variability is a possible mechanism of reduced cognitive performance in elderly hypertensives. We hypothesized that altered beat-to-beat systolic BP variability is associated with reduced global cognitive performance in elderly hypertensive subjects. In exploratory analyses, we also studied the correlation between diverse discrete cognitive domains and indices of systolic BP and heart rate variability. Disproving our initial hypothesis, we have shown that hypertension and low education, but not indices of systolic BP and heart rate variability, were independent predictors of lower global cognitive performance. However, exploratory analyses showed that the systolic BP variability in semi-upright position was an independent predictor of matrix reasoning (B=0.08±.03, P-value=0.005), whereas heart rate variability in semi-upright position was an independent predictor of the executive function score (B=-6.36±2.55, P-value=0.02). We conclude that myogenic vascular and sympathetic modulation of systolic BP do not contribute to reduced global cognitive performance in treated hypertensive subjects. Nevertheless, our results suggest that both systolic BP and heart rate variability might be associated with modulation of frontal lobe cognitive domains, such as executive function and matrix reasoning. PMID:25518896

  12. Determinants of heart rate variability

    Microsoft Academic Search

    Hisako Tsuji; Ferdinand J. Venditti; Emily S. Manders; Jane C. Evans; Martin G. Larson; Charles L. Feldman; Daniel Levy

    1996-01-01

    Objectives. This study sought to examine clinical determinants of heart rate variability and to report normative reference values for eight heart rate variability measures.Background. Although the clinical implications of heart rate variability have been described, clinical determinants and normative values of heart rate variability measures have not been studied systematically in a large community-based population.Methods. The first 2 h of

  13. Blood lactate, heart rate and rating of perceived exertion responses of elite surf lifesavers to high-performance competition.

    PubMed

    Sinclair, Wade H; Kerr, Rebecca M; Spinks, Warwick L; Leicht, Anthony S

    2009-01-01

    A paucity of empirical research exists into surf lifesaving competition from which coaches and athletes may formulate training and recovery strategies. Seventeen (male=9; female=8) high-performance surf lifesavers (21.2+/-3.9 years) contested multiple rounds of team and individual events at a 2-day surf lifesaving competition. Individual events consisted of the multi-discipline ironman (IRON), paddle board (BOARD) and surf swim (SWIM). Blood lactate (BLa), rating of perceived exertion (RPE) and heart rate (HR) were determined following heats, semi-finals and final. IRON HR and RPE following semi-finals (153.0+/-21.6beatsmin(-1) and 14.4+/-1.5) and final (171.0+/-9.1beatsmin(-1) and 19.1+/-0.2) were greater than heats (141.8+/-17.2beatsmin(-1) and 12.0+/-1.9; p<0.05) and final BLa (10.5+/-2.8mmolL(-1)) was greater than heats (5.8+/-3.6mmolL(-1); p<0.05). BOARD BLa and HR were greater after the final (9.0+/-2.8mmolL(-1) and 159.0+/-19.9beatsmin(-1)) compared to heats (4.7+/-2.4mmolL(-1) and 133.0+/-17.1beatsmin(-1); p<0.05). No significant differences were identified for SWIM. RPE-HR relationships were identified for pooled IRON and BOARD results following semi-finals (0.668; p<0.05) and finals (r=0.741; p<0.05). In conclusion, high-performance surf lifesavers employ race strategies with all-out maximal exercise limited to semi-finals and finals. PMID:18162440

  14. Variable Effects of Physical Training of Heart Rate Variability, Heart Rate Recovery, and Heart Rate Turbulence in Chronic Heart Failure

    Microsoft Academic Search

    EWA PIOTROWICZ; RAFA? BARANOWSKI; MA?GORZATA PIOTROWSKA; TOMASZ ZIELI?SKI; RYSZARD PIOTROWICZ

    2009-01-01

    Background: Heart rate variability (HRV), heart rate turbulence (HRT), and heart rate recovery (HRR), indices that reflect autonomic nervous system (ANS) activity, are outcome predictors in patients with chronic heart failure (CHF). It is not clear, however, whether they reflect the same components of ANS activity. No study has examined the effects of physical training (PT) training on HRV, HRT,

  15. Heart rate reduction and longevity in mice.

    PubMed

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

    2015-03-01

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

  16. Heart rate variability: a review

    Microsoft Academic Search

    U. Rajendra Acharya; Paul K. Joseph; N. Kannathal; Choo Min Lim; Jasjit S. Suri

    2006-01-01

    Heart rate 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 Heart rate (HR) is

  17. Regulation of Human Heart Rate

    NSDL National Science Digital Library

    Ingrid Waldron

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

  18. Nonlinear analysis of the performance and reliability of wavelet singularity detection based denoising for doppler ultrasound fetal heart rate signals

    Microsoft Academic Search

    S. Papadimitriou; A. Bezerianos

    1999-01-01

    Many studies on the physiology of the cardiovascular system revealed that nonlinear chaotic dynamics govern the generation of the heart rate signal. This is also valid for the fetal heart rate (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

  19. Sensitivity of monthly heart rate and psychometric measures for monitoring physical performance in highly trained young handball players.

    PubMed

    Buchheit, M

    2015-05-01

    The aim of the present study was to examine whether monthly resting heart rate (HR), HR variability (HRV) and psychometric measures can be used to monitor changes in physical performance in highly-trained adolescent handball players. Data were collected in 37 adolescent players (training 10±2.1?h.wk(-1)) on 11 occasions from September to May during the in-season period, and included an estimation of training status (resting HR and HRV, the profile of mood state (POMS) questionnaire), and 3 physical performance tests (a 10-m sprint, a counter movement jump and a graded aerobic intermittent test, 30-15 Intermittent Fitness Test). The sensitivity of HR and psychometric measures to changes in physical performance was poor (performance measures. The specificity was however strong (>?75%), irrespective of the markers and the performance measures. Finally, the difference in physical performance between players with better vs. worse estimated training status were all almost certainly trivial. The present results highlight the limitation of monthly measures of resting HR, HRV and perceived mood and fatigue for predicting in-season changes in physical performance in highly-trained adolescent handball players. This suggests that more frequent monitoring might be required, and/or that other markers might need to be considered. PMID:25429552

  20. Assessment of gravitational stress on heart rate variability during maneuvers on high performance jet flights.

    PubMed

    Di Rienzo, Marco; Castiglioni, Paolo; Meriggi, Paolo; Rizzo, Francesco; Trivelloni, Pierandrea; Cacopardo, Salvatore; Guadagno, Anton Giulio

    2010-01-01

    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

  1. Heart rate and exercise intensity during sports activities. Practical application.

    PubMed

    Karvonen, J; Vuorimaa, T

    1988-05-01

    Variations in heart rate during exercise correlate with changes of exercise intensity and may be measured directly by radiotelemetry and continuous ECG recording. The heart rate can also be recorded in the memory of a microcomputer, which can be carried on the wrist as easily as a watch. The device has a transmitter and a receiver. By recording the heart rate during a training session or a segment of training, and calculating the average of the heart rate and comparing this average to both the maximum heart rate of the individual and his heart rate at rest, the relative heart rate to the intensity of the work load (% maximum heart rate) can be calculated. These results are useful in planning optimal training intensities for both the healthy and rehabilitating athlete. The use of target heart rate as a tool for exercise prescription is common. It represents the percentage difference between resting and maximum heart rate added to the resting heart rate. For calculating target heart rate there are also 2 other methods. The first represents the percentage of the maximum heart rate (%HRmax) calculated from zero to peak heart rate. The second represents the heart rate at a specified percentage of maximum MET (VO2max). An appropriate individual heart rate for each level of an endurance performance is best determined in the laboratory. This is carried out by increasing the speed of the runner in stages on a treadmill and by measuring the oxygen uptake, the lactic acid concentration in the blood and corresponding variations in the heart rate.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3387734

  2. Heart Rate Variability (HRV) biofeedback: a new training approach for operator’s performance enhancement

    Microsoft Academic Search

    Auditya Purwandini Sutarto; Muhammad Nubli Abdul Wahab; Nora Mat Zin

    1970-01-01

    The widespread implementation of advanced and complex systems requires predominantly operators’ cognitive functions and less importance of human manual control. On the other hand, most operators perform their cognitive functions below their peak cognitive capacity level due to fatigue, stress, and boredom. Thus, there is a need to improve their cognitive functions during work. The goal of this paper is

  3. Perceived exertion and heart rate models for estimating metabolic workload in elite British soldiers performing a backpack load-carriage task.

    PubMed

    Simpson, Richard J; Graham, Scott M; Florida-James, Geraint D; Connaboy, Christopher; Clement, Richard; Jackson, Andrew S

    2010-10-01

    Identifying field measures to estimate backpack load-carriage work intensity in elite soldiers is of interest to the military. This study developed rating of perceived exertion (RPE) and heart rate models to define metabolic workload for a backpack load-carriage task valid for a population of elite soldiers using serial data. Male soldiers (n = 18) from the British Parachute or Special Air Service Regiment completed an incremental treadmill walking and (or) running protocol while carrying a 20-kg backpack. Heart rate, RPE, and oxygen uptake were recorded at each incremental stage of the protocol. Linear mixed models were used to model the RPE and heart rate data in the metric of measured peak oxygen uptake. Workload was accurately estimated using RPE alone (SE = 6.03), percentage of estimated maximum heart rate (%E-MHR) (SE = 6.9), and percentage of measured maximum heart rate (%M-MHR) (SE = 4.9). Combining RPE and %E-MHR resulted in a field measure with an accuracy (SE = 4.9) equivalent to the %M-MHR model. We conclude that RPE, %E-MHR, and %M-MHR provide accurate field-based proxy measures of metabolic workload in elite British soldiers performing a backpack load-carriage task. The model is accurate for the metabolic range measured by these serial data for the backpack load-carriage task. PMID:20962921

  4. The Effects of Specific Respiratory Rates on Heart Rate and Heart Rate Variability

    Microsoft Academic Search

    Hye-Sue Song; Paul M. Lehrer

    2003-01-01

    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 heart rate variability (HRV). Data were collected 16 times at each respiratory rate on 3 female volunteers, and 12 times on 2 female volunteers. Although mean heart rates did not differ among these

  5. Analysis of Heart Rate Variability

    Microsoft Academic Search

    B. Mc A. SAYKRS

    1973-01-01

    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

  6. Heart rate variability in weightlifters

    Microsoft Academic Search

    E. V. Oreshnikov; V. F. Tihonov; T. V. Agafonkina

    2009-01-01

    On the basis of the literature and original data, heart rate variability (HRV) in weightlifters has been studied. The results\\u000a showed that the distribution mode (a parameter of mathematical analysis that is equal to the most frequent length of RR intervals)\\u000a indicates the intensity of physical exercise. Specific changes in the autonomic balance in athletes as dependent on their\\u000a degree

  7. [Heart rate: clinical variable and risk marker].

    PubMed

    Custodis, F; Reil, J-C; Schirmer, S H; Adam, O; Möhlenkamp, S; Laufs, U; Böhm, M

    2014-08-01

    Heart rate is an easily accessible clinical variable with wide-ranging prognostic impact. Elevated resting heart rate predicts an elevated cardiovascular risk. Epidemiological studies demonstrate a relevant association between heart rate and survival in individuals without diagnosed cardiovascular disease and with cardiovascular disease like hypertension, coronary artery disease (CAD) and heart failure. Whereas a goal directed pharmacological heart rate reduction is not supported by clinical evidence for primary prevention it plays a prognostic role for patients with CAD? and chronic heart failure. Moreover heart rate can be characterized as an independent risk factor for patients with heart failure and potentially for those with CAD. As a result the common guidelines recommend heart rate reduction as a target of therapy. PMID:25093954

  8. An Analysis of Heart Rate Variability

    Microsoft Academic Search

    H. LUCZAK; W. LAURIG

    1973-01-01

    Proceeding from a formal definition of heart rate variability, some mathematical and statistical techniques from sampling statistics and time series analysis for the analytical evaluation of heart rate variability for ergonomics purposes are presented and compared. The concept of sampling statistics gives a measure of heart rate variability, arrived at by combining two measures, which were chosen according to a

  9. Validation of the Polar Heart Rate Monitor for Assessing Heart Rate During Physical and Mental Stress

    Microsoft Academic Search

    Jeffrey L. Goodie; Kevin T. Larkin; Scott Schauss

    2000-01-01

    The Polar Vantage XL heart rate monitor provides an ambulatory, inexpensive method of continuously measuring heart rate. To examine the validity of the Polar monitor for measuring heart rate during resting periods and while engaging in two stressful tasks, 30 students participated in a 1-hour laboratory session. Heart rates were measured simultaneously using the Polar monitor and electrocardiography (ECG) during

  10. How to Take Your Heart Rate

    MedlinePLUS

    ... effective for your body. How to Take Your Heart Rate Taking your pulse during physical activity allows you to measure how hard you are ... 68 95 115 135 Page 2 of 2 Physical Activity Handouts • P09 Version 5.0 The chart illustrates target heart rate ranges for exercise based on the maximal heart ...

  11. Heart rate and heart rate variability in subjectively reported insomnia.

    PubMed

    Spiegelhalder, Kai; Fuchs, Lena; Ladwig, Johannes; Kyle, Simon D; Nissen, Christoph; Voderholzer, Ulrich; Feige, Bernd; Riemann, Dieter

    2011-03-01

    According to epidemiological studies, insomnia is associated with cardiovascular mortality. However, it is yet to be determined whether this link is mediated by known cardiovascular risk factors. The current study aimed at investigating the association between primary insomnia, defined as subjectively reported sleep disturbance in the absence of any other pathology or substance intake, and alterations in polysomnographically determined nocturnal heart rate (HR) and heart rate variability (HRV). A total of 4,581 nocturnal short-term electrocardiographic recordings (5 min each) from 104 participants (58 with primary insomnia, 46 healthy controls) were evaluated for HR as well as for time and frequency domain measures of HRV. In the primary insomnia group, we found a lower wake-to-sleep HR reduction and a lower standard deviation of RR intervals (SDNN) compared to healthy controls. However, between-group differences in resting HR were not found, and previous results of an increase in sympathovagal balance and a decrease in parasympathetic nocturnal activity in objectively determined insomnia could not be confirmed in our sample of self-report insomnia patients. When restricting our analyses to insomnia patients with objectively determined short sleep duration, we found reduced parasympathetic activity as indicated by decreased high frequency power of HRV, as well as decreased root mean square of successive RRI differences (RMSSD) and percentage of successive RRIs that differ by more than 50 ms (pNN50) values. A lower wake-to-sleep HR reduction and alterations in HRV variables might, at least partially, mediate the increased rates of cardiovascular morbidity and mortality observed in insomnia patients. PMID:20626615

  12. Heart rate during training and competition for longdistance running

    Microsoft Academic Search

    M. I. Lambert; Z. H. Mbambo; A. St Clair Gibson

    1998-01-01

    Heart rate monitors are used widely by scientists, coaches and sports participants to monitor heart rate during physical activity. Although there are data that show that heart rate monitors measure heart rate accurately during a range of physical activities, there is less consensus on the interpretation of heart rate data. The day-to-day variation in heart rate under controlled submaximal exercise

  13. Long?term Cardiovascular Risks Associated With an Elevated Heart Rate: The Framingham Heart Study

    PubMed Central

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

    2014-01-01

    Background Higher heart rate has been associated with an adverse prognosis, but most prior studies focused on individuals with known cardiovascular disease or examined a limited number of outcomes. We sought to examine the association of baseline heart rate with both fatal and nonfatal outcomes during 2 decades of follow?up. Methods and Results Our study included 4058 Framingham Heart Study participants (mean age 55 years, 56% women). Cox models were performed with multivariable adjustment for clinical risk factors and physical activity. A total of 708 participants developed incident cardiovascular disease (303 heart failure, 343 coronary heart disease, and 216 stroke events), 48 received a permanent pacemaker, and 1186 died. Baseline heart rate was associated with incident cardiovascular disease (hazard ratio [HR] 1.15 per 1 SD [11 bpm] increase in heart rate, 95% CI 1.07 to 1.24, P=0.0002), particularly heart failure (HR 1.32, 95% CI 1.18 to 1.48, P<0.0001). Higher heart rate was also associated with higher all?cause (HR 1.17, 95% CI 1.11 to 1.24, P<0.0001) and cardiovascular mortality (HR 1.18, 95% CI 1.04 to 1.33, P=0.01). Spline analyses did not suggest a lower threshold beyond which the benefit of a lower heart rate abated or increased. In contrast, individuals with a higher heart rate had a lower risk of requiring permanent pacemaker placement (HR 0.55, 95% CI 0.38 to 0.79, P=0.001). Conclusions Individuals with a higher heart rate are at elevated long?term risk for cardiovascular events, in particular, heart failure, and all?cause death. On the other hand, a higher heart rate is associated with a lower risk of future permanent pacemaker implantation. PMID:24811610

  14. Acoustically based fetal heart rate monitor

    NASA Technical Reports Server (NTRS)

    Baker, Donald A.; Zuckerwar, Allan J.

    1991-01-01

    The acoustically based fetal heart rate 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.

  15. Periodic heart rate decelerations in premature infants

    PubMed Central

    Flower, Abigail A.; Moorman, J. Randall; Lake, Douglas E.; Delos, John B.

    2010-01-01

    The pacemaking system of the heart is complex; a healthy heart constantly integrates and responds to extracardiac signals, resulting in highly complex heart rate patterns with a great deal of variability. In the laboratory and in some pathological or age-related states, however, dynamics can show reduced complexity that is more readily described and modeled. Reduced heart rate complexity has both clinical and dynamical significance – it may provide warning of impending illness or clues about the dynamics of the heart’s pacemaking system. In this paper, we describe uniquely simple and interesting heart rate dynamics that we have observed in premature human infants -- reversible transitions to large-amplitude periodic oscillations -- and we show that the appearance and disappearance of these periodic oscillations can be described by a simple mathematical model, a Hopf bifurcation. PMID:20407086

  16. Heart-Rate and Breath-Rate Monitor

    NASA Technical Reports Server (NTRS)

    Cooper, T. G.

    1983-01-01

    Circuit requiring only four integrated circuits (IC's) measures both heart rate 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.

  17. Heart rates of participants in wheelchair sports.

    PubMed

    Coutts, K D

    1988-02-01

    The relative stress of participation in wheelchair basketball, volleyball, tennis, and racquetball were determined by monitoring the heart rates of wheelchair athletes. Heart rates 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 an international sport classification system. Average heart rates were 89 beats/min for tennis 'practice', 96 for racquetball 'practice' 107 for volleyball 'practice', 114 for volleyball 'game', 127 for tennis 'game', 129 for basketball 'practice', 135 for racquetball 'game', and 149 for basketball 'game' conditions. The percentage of time when heart rates were above 140 beats/min, followed the same pattern as the average heart rates and ranged from 0 to 62%. PMID:3353125

  18. A new approach to detect congestive heart failure using short-term heart rate variability measures.

    PubMed

    Liu, Guanzheng; Wang, Lei; Wang, Qian; Zhou, Guangmin; Wang, Ying; Jiang, Qing

    2014-01-01

    Heart rate variability (HRV) analysis has quantified the functioning of the autonomic regulation of the heart and heart's ability to respond. However, majority of studies on HRV report several differences between patients with congestive heart failure (CHF) and healthy subjects, such as time-domain, frequency domain and nonlinear HRV measures. In the paper, we mainly presented a new approach to detect congestive heart failure (CHF) based on combination support vector machine (SVM) and three nonstandard heart rate variability (HRV) measures (e.g. SUM_TD, SUM_FD and SUM_IE). The CHF classification model was presented by using SVM classifier with the combination SUM_TD and SUM_FD. In the analysis performed, we found that the CHF classification algorithm could obtain the best performance with the CHF classification accuracy, sensitivity and specificity of 100%, 100%, 100%, respectively. PMID:24747432

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

    Microsoft Academic Search

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

    1999-01-01

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

  20. Statistical analysis of heart rate and heart rate variability monitoring through the use of smart phone cameras.

    PubMed

    Bolkhovsky, Jeffrey B; Scully, Christopher G; Chon, Ki H

    2012-01-01

    Video recordings of finger tips made using a smartphone camera contain a pulsatile component caused by the cardiac pulse equivalent to that present in a photoplethysmographic signal. By performing peak detection on the pulsatile signal it is possible to extract a continuous heart rate signal. We performed direct comparisons between 5-lead electrocardiogram based heart rate variability measurements and those obtained from an iPhone 4s and Motorola Droid derived pulsatile signal to determine the accuracy of heart rate variability measurements obtained from the smart phones. Monitoring was performed in the supine and tilt positions for independent iPhone 4s (2 min recordings, n=9) and Droid (5 min recordings, n=13) experiments, and the following heart rate and heart rate variability parameters were estimated: heart rate, low frequency power, high frequency power, ratio of low to high frequency power, standard deviation of the RR intervals, and root mean square of successive RR-differences. Results demonstrate that accurate heart rate variability parameters can be obtained from smart phone based measurements. PMID:23366214

  1. Heart rate and oxygen uptake response to exercise in children with low peak exercise heart rate

    Microsoft Academic Search

    I. M. Schulze-Neick; H. U. Wessel; M. H. Paul

    1992-01-01

    Normal children achieve the same increase of oxygen uptake (VO2) in response to exercise even though resting and submaximal exercise heart rates vary greatly as a function of age, body size and physical conditioning. To determine whether the VO2 response to exercise is altered when heart rate is significantly reduced by heart disease, we compared 78 children who achieved a

  2. ARCHIVAL REPORT Ambulatory and Challenge-Associated Heart Rate

    E-print Network

    Mujica-Parodi, Lilianne R.

    ARCHIVAL REPORT Ambulatory and Challenge-Associated Heart Rate Variability Measures Predict Cardiac: Heart rate variability (HRV) measures homeostatic regulation of the autonomic nervous system in response enhance predictive value. Key Words: Anxiety, autonomic, depression, emotion, fear, heart rate variability

  3. Heart rate indication using musical data.

    PubMed

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

    2002-07-01

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

  4. A stochastic sequential model for heart rate response

    Microsoft Academic Search

    David E. Greene

    1988-01-01

    A stochastic sequential model is applied to heart-rate response during exercise. Heart-rate-need functions are found through steady-state analysis. Heart rates of two subjects are used to track the heart-rate-need functions in a cycle ergometer experiment in a manner represented by a first-order sequential model. Under conditions of increased physical or emotional stress, heart rates can track the heart-rate-need functions in

  5. Heart Rate Variability Biofeedback for Major Depression

    Microsoft Academic Search

    Maria Karavidas

    Heart rate variability for the treatment of major depression is a novel, alternative approach that can offer symptom reduction with minimal-to-no noxious side effects. The following material will illustrate some of the work being conducted at our laboratory to demonstrate the efficacy of heart rate variability. Namely, results will be presented regarding our published work on an initial open-label study

  6. Dynamic heart rate measurements from video sequences.

    PubMed

    Yu, Yong-Poh; Raveendran, P; Lim, Chern-Loon

    2015-07-01

    This paper shows how dynamic heart rate measurements that are typically obtained from sensors mounted near to the heart can also be obtained from video sequences. In this study, two experiments are carried out where a video camera captures the facial images of the seven subjects. The first experiment involves the measurement of subjects' increasing heart rates (79 to 150 beats per minute (BPM)) while cycling whereas the second involves falling heart beats (153 to 88 BPM). In this study, independent component analysis (ICA) is combined with mutual information to ensure accuracy is not compromised in the use of short video duration. While both experiments are going on measures of heartbeat using the Polar heart rate monitor is also taken to compare with the findings of the proposed method. Overall experimental results show the proposed method can be used to measure dynamic heart rates where the root mean square error (RMSE) and the correlation coefficient are 1.88 BPM and 0.99 respectively. PMID:26203374

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

    PubMed

    Bair, Christine Caldwell

    2008-01-01

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

  8. Acupuncture regulates the heart rate variability.

    PubMed

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

    2015-04-01

    Acupuncture is widely used in clinical practice. According to traditional acupuncture theory, the Neiguan acupoint (PC6) is one of the most commonly used acupoints and is indicated for treating cardiovascular-related disorders. We present the case of a 27-year-old female who had been diagnosed with ventricular septal defect and had undergone surgery to repair the defect at the age of 11 years. The patient had no obvious symptoms, such as palpitations and difficulty breathing. However, while performing electrocardiography (ECG), we found that she suffered from arrhythmia, and therefore, we treated her by acupuncture at the left PC6. An ECG monitor was used to record data during the entire acupuncture procedure, which was divided into the following three segments: prior to, during, and after acupuncture. Various indices of heart rate variability (HRV) were then determined and analyzed. The results indicate that acupuncture can regulate the HRV effectively; however, more studies are needed to confirm this finding. PMID:25952126

  9. Fetal heart rate and fetal heart rate variability in Lipizzaner broodmares.

    PubMed

    Baska-Vincze, Boglárka; Baska, Ferenc; Szenci, Ottó

    2015-03-01

    Monitoring fetal heart rate (FHR) and fetal heart rate variability (FHRV) helps to understand and evaluate normal and pathological conditions in the foal. The aim of this study was to establish normal heart rate reference values for the ongoing equine pregnancy and to perform a heart rate variability (HRV) time-domain analysis in Lipizzaner mares. Seventeen middle- and late-term (days 121-333) pregnant Lipizzaner mares were examined using fetomaternal electrocardiography (ECG). The mean FHR (P = 0.004) and the standard deviation of FHR (P = 0.012) significantly decreased during the pregnancy. FHR ± SD values decreased from 115 ± 35 to 79 ± 9 bpm between months 5 and 11. Our data showed that HRV in the foal decreased as the pregnancy progressed, which is in contrast with the findings of earlier equine studies. The standard deviation of normal-normal intervals (SDNN) was higher (70 ± 25 to 166 ± 108 msec) than described previously. The root mean square of successive differences (RMSSD) decreased from 105 ± 69 to 77 ± 37 msec between the 5th and 11th month of gestation. Using telemetric ECG equipment, we could detect equine fetal heartbeat on day 121 for the first time. In addition, the large differences observed in the HR values of four mare-fetus pairs in four consecutive months support the assumption that there might be 'high-HR' and 'low-HR' fetuses in horses. It can be concluded that the analysis of FHR and FHRV is a promising tool for the assessment of fetal well-being but the applicability of these parameters in the clinical setting and in studs requires further investigation. PMID:25655416

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

    ERIC Educational Resources Information Center

    Stone, Michael H.; And Others

    1987-01-01

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

  11. Heart Rate Recovery: Validation and Methodologic Issues

    Microsoft Academic Search

    Katerina Shetler; Rachel Marcus; Victor F. Froelicher; Shefali Vora; Damayanthi Kalisetti; Manish Prakash; Jonathan Myers

    2001-01-01

    OBJECTIVES The goal of this study was to validate the prognostic value of the drop in heart rate (HR) after exercise, compare it to other test responses, evaluate its diagnostic value and clarify some of the methodologic issues surrounding its use. BACKGROUND Studies have highlighted the value of a new prognostic feature of the treadmill test—rate of recovery of HR

  12. Heart-rate pulse-shift detector

    NASA Technical Reports Server (NTRS)

    Anderson, M.

    1974-01-01

    Detector circuit accurately separates and counts phase-shift pulses over wide range of basic pulse-rate frequency, and also provides reasonable representation of full repetitive EKG waveform. Single telemeter implanted in small animal monitors not only body temperature but also animal movement and heart rate.

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

    PubMed

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

    2015-04-01

    Heart rate is a useful neurophysiological sign when monitoring seizures in patients with epilepsy. In an ambulatory setting, heart rate is measured with ECG involving electrodes on the skin. This method is uncomfortable which is burdensome for patients and is sensitive to motion artifacts, which decrease the usability of measurements. In this study, green light photoplethysmography, an optical technique arising from the fitness industry, was evaluated for usefulness in a medical setting. Simultaneous overnight measurements of HR with a commercially available optical heart rate (OHR) sensor and with ECG (HRECG) were performed in 7 patients with epilepsy. Overall, there was no significant difference between OHR and HRECG in random 10-minute periods during wakefulness (p=0.69) and sleep (p=1.00). The Bland-Altman analysis showed negligible mean differences. Limits of agreement were higher during wakefulness and during the occurrence of two seizures possibly because of less reliable HRECG measurements due to motion artifacts. Optical heart rate seems less sensitive to these motion artifacts, and measurements are more user-friendly. The optical heart rate sensor may fill the gap of systems for ambulatory heart rate monitoring and can be especially useful in the context of seizure detection in patients with epilepsy. PMID:25812938

  14. Heart rate variability in smokers, sedentary and aerobically fit individuals

    Microsoft Academic Search

    Dympna Gallagher; Thomas Terenzi; Ronald de Meersman

    1992-01-01

    To test the hypothesis that certain lifestyles may affect cardiovascular regulatory mechanisms, heart rate variability (HRV) among three age-matched groups with different lifestyles (smoking, sedentary and aerobically fit) were compared. Heart rate variability was defined as the difference in heart rate during inhalation vs. exhalation. Heart rate was obtained from normal RR intervals, using a continuous electrocardiogram recording, while subjects

  15. Measurement characteristics of the ultrasound heart rate monitor

    Microsoft Academic Search

    Y. Noguchi; H. Mamune; S. Sugimoto; J. Yoshida; H. Sasa; H. Kobayashi; M. Kobayashi

    1994-01-01

    It was reported that the measurement error of the fetal heart rate variability (FHRV), which was obtained by a ultrasound heart rate monitor with the Doppler signal, was large even if the auto-correlation technique was used. Nevertheless, fetal heart rate monitoring by the ultrasound heart rate monitor is necessary to determine the status of the fetus because an invasive test

  16. Age differences in high frequency phasic heart rate variability and performance response to increased executive function load in three executive function tasks

    PubMed Central

    Byrd, Dana L.; Reuther, Erin T.; McNamara, Joseph P. H.; DeLucca, Teri L.; Berg, William K.

    2015-01-01

    The current study examines similarity or disparity of a frontally mediated physiological response of mental effort among multiple executive functioning tasks between children and adults. Task performance and phasic heart rate variability (HRV) were recorded in children (6 to 10 years old) and adults in an examination of age differences in executive functioning skills during periods of increased demand. Executive load levels were varied by increasing the difficulty levels of three executive functioning tasks: inhibition (IN), working memory (WM), and planning/problem solving (PL). Behavioral performance decreased in all tasks with increased executive demand in both children and adults. Adults’ phasic high frequency HRV was suppressed during the management of increased IN and WM load. Children’s phasic HRV was suppressed during the management of moderate WM load. HRV was not suppressed during either children’s or adults’ increasing load during the PL task. High frequency phasic HRV may be most sensitive to executive function tasks that have a time-response pressure, and simply requiring performance on a self-paced task requiring frontal lobe activation may not be enough to generate HRV responsitivity to increasing demand. PMID:25798113

  17. AUTONOMIC CONTROL OF HEART RATE AFTER EXERCISE IN TRAINED WRESTLERS

    PubMed Central

    Báez, San Martín E.; Von Oetinger, A.; Cañas, Jamett R.; Ramírez, Campillo R.

    2013-01-01

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

  18. Physiological control of intraaorta pump based on heart rate.

    PubMed

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

    2011-01-01

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

  19. Test anxiety, heart rate and performance in A-level French speaking mock exams: an exploratory study

    Microsoft Academic Search

    Anthony L. Daly; Suzanne Chamberlain; V. Spalding

    2011-01-01

    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

  20. Heart rate recovery: validation and methodologic issues

    Microsoft Academic Search

    Katerina Shetler; Rachel Marcus; Victor F Froelicher; Shefali Vora; Damayanthi Kalisetti; Manish Prakash; Dat Do; Jon Myers

    2001-01-01

    ObjectivesThe goal of this study was to validate the prognostic value of the drop in heart rate (HR) after exercise, compare it to other test responses, evaluate its diagnostic value and clarify some of the methodologic issues surrounding its use.

  1. Unconstrained heart-rate monitoring during bathing.

    PubMed

    Tamura, T; Yoshimura, T; Nakajima, K; Miike, H; Togawa, T

    1997-01-01

    An unconstrained electrocardiograph (ECG) and heart-rate monitor was designed to record ECG measurements in the bathtub. The apparatus consists of analog and digital parts. In the analog part, electrocardiographic signals obtained from electrodes placed inside the bathtub were amplified approximately 4,000 times. The electrodes were made of stainless steel and were 104 x 74 x 0.5 mm in size, including the absorbent sponge covers. Each electrode fitted into a plastic case 110 x 79 x 23 mm in size. Working electrodes were placed 20 cm from the bottom of the long bathtub wall, close to the position of the immersed trunk, and a reference electrode was placed 5 cm from the bottom of the side wall close to the toe position. In the digital part of the system the heart rate was calculated from the R-R interval of each ECG pulse and the calculated data were stored in a random-access memory. These stored data were transferred to a personal computer through an RS 232C interface and analyzed. The heart rates obtained from the bathtub ECG agreed with those obtained from a body-surface ECG. During measurements in bathwater with various concentrations of sodium chloride, the amplitude of the electrocardiographic waveform decreased as the electrical conductivity increased. The frequency characteristics of the bathtub ECG varied with the bathtub dimensions and the electrical conductivity of the water. Using this apparatus, heart-rate measurements can be obtained easily and noninvasively, but interpretation of the ECG signal requires great care. This monitor could be used as a home health heart-rate monitor. PMID:9262839

  2. Optimization of pharmacotherapy in chronic heart failure: is heart rate adequately addressed?

    PubMed

    Franke, Jennifer; Wolter, Jan Sebastian; Meme, Lillian; Keppler, Jeannette; Tschierschke, Ramon; Katus, Hugo A; Zugck, Christian

    2013-01-01

    The aim of the study is to evaluate the use of beta-blockers in chronic heart failure (CHF) and the extent of heart rate reduction achieved in clinical practice and to determine differences in outcome of patients who fulfilled select inclusion criteria of the SHIFT study according to resting heart rate modulated by beta-blocker therapy. We evaluated an all-comer population of our dedicated CHF outpatient clinic between 2006 and 2010. For inclusion, individually optimized doses of guideline-recommended pharmacotherapy including beta-blockers had to be maintained for at least 3 months and routine follow-up performed at our outpatient CHF-clinic thereafter. Treatment dosages of beta-blockers, and demographic and clinical profiles including resting heart rate were assessed. The outcome of patients who fulfilled select inclusion criteria of the SHIFT study (left-ventricular ejection fraction (LVEF) ?35 %, sinus rhythm, NYHA II-IV) and were followed-up for at least 1 year was stratified according to resting heart rates: ?75 versus <75 bpm and ?70 versus <70 bpm. The composite primary endpoint was defined as all-cause death or hospital admission for worsening heart failure during 12-month follow-up. In total, 3,181 patients were assessed in regard to treatment dosages of beta-blockers, and demographic and clinical profiles including resting heart rate. Of the overall studied population, 443 patients fulfilled all inclusion criteria and entered outcome analysis. Median observation time of survivors was 27.5 months with 1,039.7 observation-years in total. Up-titration to at least half the evidence-based target dose of beta-blockers was achieved in 69 % and full up-titration in 29 % of these patients. Patients with increased heart rates were younger, more often male, exhibited a higher NYHA functional class and lower LVEF. The primary endpoint occurred in 21 % of patients in the ?70 bpm group versus 9 % of patients in the group with heart rates <70 bpm (p <0.01). Likewise, comparing the groups ?75 and <75 bpm, the primary endpoint was significantly increased in the group of patients with heart rates ?75 bpm 27 vs. 12.2 %; p < 0.01). 5-year event-free survival was significantly lower among patients with heart rates ?70 bpm as compared to those with <70 bpm (log-rank test p < 0.05) and among patients in the ?75 bpm group versus <75 bpm group (log-rank test p < 0.01). In conclusion, in clinical practice, 53 % of CHF patients have inadequate heart rate control (heart rates ?75 bpm) despite concomitant beta-blocker therapy. In this non-randomized cohort, adequate heart rate control under individually optimized beta-blocker therapy was associated with improved mid- and long-term clinical outcome up to 5 years. As further up titration of beta-blockers is not achievable in many patients, the administration of a selective heart rate lowering agent, such as ivabradine adjuvant to beta-blockers may pose an opportunity to further modulate outcome. PMID:22760479

  3. Neuroanatomical substrates for the volitional regulation of heart rate

    PubMed Central

    Jones, Catherine L.; Minati, Ludovico; Nagai, Yoko; Medford, Nick; Harrison, Neil A.; Gray, Marcus; Ward, Jamie; Critchley, Hugo D.

    2015-01-01

    The control of physiological arousal can assist in the regulation of emotional state. A subset cortical and subcortical brain regions are implicated in autonomic control of bodily arousal during emotional behaviors. Here, we combined human functional neuroimaging with autonomic monitoring to identify neural mechanisms that support the volitional regulation of heart rate, a process that may be assisted by visual feedback. During functional magnetic resonance imaging (fMRI), 15 healthy adults performed an experimental task in which they were prompted voluntarily to increase or decrease cardiovascular arousal (heart rate) during true, false, or absent visual feedback. Participants achieved appropriate changes in heart rate, without significant modulation of respiratory rate, and were overall not influenced by the presence of visual feedback. Increased activity in right amygdala, striatum and brainstem occurred when participants attempted to increase heart rate. In contrast, activation of ventrolateral prefrontal and parietal cortices occurred when attempting to decrease heart rate. Biofeedback enhanced activity within occipito-temporal cortices, but there was no significant interaction with task conditions. Activity in regions including pregenual anterior cingulate and ventral striatum reflected the magnitude of successful task performance, which was negatively related to subclinical anxiety symptoms. Measured changes in respiration correlated with posterior insula activation and heart rate, at a more lenient threshold, change correlated with insula, caudate, and midbrain activity. Our findings highlight a set of brain regions, notably ventrolateral prefrontal cortex, supporting volitional control of cardiovascular arousal. These data are relevant to understanding neural substrates supporting interaction between intentional and interoceptive states related to anxiety, with implications for biofeedback interventions, e.g., real-time fMRI, that target emotional regulation. PMID:25992711

  4. Analysis of the heart rate variability using stress tests

    Microsoft Academic Search

    S. V. Bozhokin; I. M. Shchenkova

    2008-01-01

    A new parameter, CS\\u000a \\u000a n\\u000a (t) (CardStress), a quantitative characteristic of the changes in the cardiovascular regulatory mechanisms based on the relative\\u000a decrease in the heart rate variability during a functional test, is proposed. Analysis of the heart rate variability was performed\\u000a in patients exposed to non-steady-state (acutely increasing) normobaric hypoxic hypoxia induced by rebreathing. The new parameter\\u000a was compared

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

    Microsoft Academic Search

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

    2009-01-01

    Detrended Fluctuation Analysis (DFA) is an algorithm widely used to determine fractal long-range correlations in physiological signals. Its application to heart rate variability (HRV) has proven useful in distinguishing healthy subjects from patients with cardiovascular disease. In this study we examined the effect of respiratory sinus arrhythmia (RSA) on the performance of DFA applied to HRV. Predictions based on a

  6. Spectral Analysis of Heart Rate Variability in Sleep

    Microsoft Academic Search

    P. BUŠEK; J. OPAVSKÝ; J. SALINGER; S. NEVŠÍMALOVÁ

    2005-01-01

    Summary Spectral analysis of heart rate variability (HRV) during overnight polygraphic recording was performed in 11 healthy subjects. The total spectrum power, power of the VLF, LF and HF spectral bands and the mean R-R were evaluated. Compared to Stage 2 and Stage 4 non-REM sleep, the total spectrum power was significantly higher in REM sleep and its value gradually

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

    Microsoft Academic Search

    François Cottin; François Durbin; Yves Papelier

    2004-01-01

    This study compared heart rate variability (HRV) in ten male judokas between two types of exercise eliciting the same near-maximal average heart rate (HR): judo wrestling vs. cycloergometric bout. Beat-to-beat RR intervals were recorded during (1) a 4-min judo randori (wrestling); (2) a 4-min cycloergometric exercise eliciting maximal oxygen consumption ( V?O 2MAX). Time series were analyzed both by short

  8. Heart Rate Variability – A Historical Perspective

    PubMed Central

    Billman, George E.

    2011-01-01

    Heart rate variability (HRV), the beat-to-beat variation in either heart rate or the duration of the R–R interval – the heart period, has become a popular clinical and investigational tool. The temporal fluctuations in heart rate exhibit a marked synchrony with respiration (increasing during inspiration and decreasing during expiration – the so called respiratory sinus arrhythmia, RSA) and are widely believed to reflect changes in cardiac autonomic regulation. Although the exact contributions of the parasympathetic and the sympathetic divisions of the autonomic nervous system to this variability are controversial and remain the subject of active investigation and debate, a number of time and frequency domain techniques have been developed to provide insight into cardiac autonomic regulation in both health and disease. It is the purpose of this essay to provide an historical overview of the evolution in the concept of HRV. Briefly, pulse rate was first measured by ancient Greek physicians and scientists. However, it was not until the invention of the “Physician’s Pulse Watch” (a watch with a second hand that could be stopped) in 1707 that changes in pulse rate could be accurately assessed. The Rev. Stephen Hales (1733) was the first to note that pulse varied with respiration and in 1847 Carl Ludwig was the first to record RSA. With the measurement of the ECG (1895) and advent of digital signal processing techniques in the 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

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

    NASA Technical Reports Server (NTRS)

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

    1996-01-01

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

  10. Age-predicted maximal heart rate revisited

    Microsoft Academic Search

    Hirofumi Tanaka; Kevin D Monahan; Douglas R Seals

    2001-01-01

    OBJECTIVESWe sought to determine a generalized equation for predicting maximal heart rate (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

  11. Heart rate variability and intima media thickness

    Microsoft Academic Search

    Nanna Hurwitz Eller; Birgitta Malmberg; Peter Bruhn

    2006-01-01

    Increased activity in the sympathetic nervous system is part of the physiological stress response and is expressed in the\\u000a heart rate variability (HRV). The objective of this study was to examine associations of HRV and intima media thickness (IMT).\\u000a In 2002, satisfactory measurements of HRV of 78 voluntary participants were made, both during a stress test and during sleep.\\u000a IMT

  12. Multiscale power analysis for heart rate variability

    NASA Astrophysics Data System (ADS)

    Zeng, Peng; Liu, Hongxing; Ni, Huangjing; Zhou, Jing; Xia, Lan; Ning, Xinbao

    2015-06-01

    We first introduce multiscale power (MSP) method to assess the power distribution of physiological signals on multiple time scales. Simulation on synthetic data and experiments on heart rate variability (HRV) are tested to support the approach. Results show that both physical and psychological changes influence power distribution significantly. A quantitative parameter, termed power difference (PD), is introduced to evaluate the degree of power distribution alteration. We find that dynamical correlation of HRV will be destroyed completely when PD>0.7.

  13. Autonomic heart rate control by multifractal tools

    Microsoft Academic Search

    D. Makowiec; R. Ga??ska; A. Rynkiewicz; J. Wdowczyk-Szulc

    \\u000a Heart rate variability of people suffering from the left ventrical systolic dysfunction and healthy ones is considered in\\u000a terms of multifractal analysis in order to investigate the scaling properties in the low, very low and ultra low frequency\\u000a bands of standard power spectral analysis. Two methods: Wavelet Transform Modulus Maxima and Multifractal Detrended Fluctuation\\u000a Analysis, are used to assess multifractal

  14. Quantitative analysis of heart rate variability

    Microsoft Academic Search

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

    1995-01-01

    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 heart rate variability (HRV). Therefore,we apply some rather unconventional methods of nonlinear dynamics to analyse the

  15. Performance of recipient hearts after heterotopic transplantation.

    PubMed

    Dor, V; Jourdan, J; Bourlon, F; Elbeze, J P; Grinneiser, D; Isetta, C; Montiglio, F

    1986-10-01

    Twenty-two heterotopic heart transplantations were performed, in 19 of which the evolution of the recipient heart was estimated. Within the first postoperative hours the recipient heart was often more effective than the donor heart. The discrepant rhythm between the 2 hearts did not result in any pathological findings. The increased pressures in the recipient's right heart always decreased, sometimes within several weeks. The left atrial volume was found to be reduced while left ventricular contraction was sometimes unchanged, sometimes improved and in a few cases showed definite improvement with a mean decrease of the ultra-sound diastolic diameter of 20 mm on echocardiography. The technique of heterotopic systems seems to be a useful indication for end-stage cardiomyopathies with pulmonary hypertension (class IV) which is generally considered a contraindication for orthotopic heart transplantation. PMID:2431501

  16. Heart Rate Changes Linked to Sexual Problems in Women

    MedlinePLUS

    ... gov/medlineplus/news/fullstory_153160.html Heart Rate Changes Linked to Sexual Problems in Women Preliminary finding ... in the length of time between heartbeats. Those changes in heart rate play a particularly important role ...

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

    PubMed

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

    2015-01-01

    Heart rate increases are a fundamental adaptation to physiological stress, while inappropriate heart rate increases are resistant to current therapies. However, the metabolic mechanisms driving heart rate acceleration in cardiac pacemaker cells remain incompletely understood. The mitochondrial calcium uniporter (MCU) facilitates calcium entry into the mitochondrial matrix to stimulate metabolism. We developed mice with myocardial MCU inhibition by transgenic expression of a dominant-negative (DN) MCU. Here, we show that DN-MCU mice had normal resting heart rates but were incapable of physiological fight or flight heart rate acceleration. We found that MCU function was essential for rapidly increasing mitochondrial calcium in pacemaker cells and that MCU-enhanced oxidative phoshorylation was required to accelerate reloading of an intracellular calcium compartment before each heartbeat. Our findings show that MCU is necessary for complete physiological heart rate acceleration and suggest that MCU inhibition could reduce inappropriate heart rate increases without affecting resting heart rate. PMID:25603276

  18. Heart Rate and Physical Activity of Children During Dental Treatment

    Microsoft Academic Search

    Howard M. Rosenberg; Aaron Honori Katcher

    1976-01-01

    Body movements and heart rate were measured during dental treatment in 58 children 3 to 12 years of age. The heart rate increased in 85% of the 34 children who moved during intraoral injection. The heart rate decreased in 71% of the children with no overt body movement during intraoral injection.

  19. Frequency component of fetal heart rate with integral function method

    Microsoft Academic Search

    Y. Noguchi; H. Kobayashi; H. Hataoka; S. Sugimoto; M. Kobayashi

    1988-01-01

    The authors have been studying the control mechanism of the fetal heart rate using a spectral analysis method which has high accuracy and a short calculation time. They have shown by simulation that frequency components of heart rate variability can be obtained more accurately even if the heart rate data contained certain errors in measurement. They report here the result

  20. ORIGINAL PAPER Modeling Heart Rate Regulation--Part II: Parameter

    E-print Network

    Olufsen, Mette Sofie

    ORIGINAL PAPER Modeling Heart Rate Regulation--Part II: Parameter Identification and Analysis K. R of this study we introduced a 17- parameter model that can predict heart rate regulation during postural change to adequately represent the observed heart rate response. In part I and in previous work (Olufsen et al. 2006

  1. Adaptive Multiscale Complexity Analysis of Fetal Heart Rate

    E-print Network

    Gonçalves, Paulo

    1 Adaptive Multiscale Complexity Analysis of Fetal Heart Rate H. Helgason(1), P. Abry(2), P. Gonc morbidity and mortality. Fetal heart rate monitoring plays an important role in early detection of acidosis of fetal heart rate data, based on producing a collection of piecewise linear approximations of varying

  2. MULTIRESOLUTION WAVELET ANALYSIS OF HEART RATE VARIABILITY FOR

    E-print Network

    Teich, Malvin C.

    MULTIRESOLUTION WAVELET ANALYSIS OF HEART RATE VARIABILITY FOR HEART-FAILURE AND HEART, heart-transplant patients, and nor- mal subjects, using wavelet-based multiresolution tech- niques is nonstationary, reflecting biological adaptability. Multiresolution wavelet analysis [4, 5, 6, 7, 8] provides

  3. Continuous positive airway pressure increases heart rate variability in heart failure patients with obstructive sleep apnoea

    Microsoft Academic Search

    Kengo Usui; Yasuyuki Kaneko

    2008-01-01

    Patients with heart failure or OSA (obstructive sleep apnoea) have reduced HF-HRV (high- frequency heart rate variability), indicating reduced cardiac vagal modulation, a marker of poor prognosis. CPAP (continuous positive airway pressure) abolishes OSA in patients with heart failure, but effects on daytime HF-HRV have not been determined. We hypothesized that, in patients with heart failure, treatment of coexisting OSA

  4. Higher heart rate and reduced heart rate variability persist during sleep in chronic fatigue syndrome: A population-based study

    Microsoft Academic Search

    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

    2007-01-01

    Autonomic nervous system (ANS) dysfunction has been suggested in patients with chronic fatigue syndrome (CFS). In this study, we sought to determine whether increased heart rate (HR) and reduced heart rate variability (HRV) parameters observed in CFS patients during wakefulness persist during sleep. To this end, we compared heart rate (HR) and HRV as indicators of ANS function in CFS

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

    NSDL National Science Digital Library

    Shoemaker, Allen L.

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

  6. Gaussian process robust regression for noisy heart rate data.

    PubMed

    Stegle, Oliver; Fallert, Sebastian V; MacKay, David J C; Brage, Søren

    2008-09-01

    Heart rate data collected during nonlaboratory conditions present several data-modeling challenges. First, the noise in such data is often poorly described by a simple Gaussian; it has outliers and errors come in bursts. Second, in large-scale studies the ECG waveform is usually not recorded in full, so one has to deal with missing information. In this paper, we propose a robust postprocessing model for such applications. Our model to infer the latent heart rate time series consists of two main components: unsupervised clustering followed by Bayesian regression. The clustering component uses auxiliary data to learn the structure of outliers and noise bursts. The subsequent Gaussian process regression model uses the cluster assignments as prior information and incorporates expert knowledge about the physiology of the heart. We apply the method to a wide range of heart rate data and obtain convincing predictions along with uncertainty estimates. In a quantitative comparison with existing postprocessing methodology, our model achieves a significant increase in performance. PMID:18713683

  7. Ordinal pattern statistics for the assessment of heart rate variability

    NASA Astrophysics Data System (ADS)

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

    2013-06-01

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

  8. Screening of obstructive sleep apnoea: heart rate spectral analysis of nocturnal pulse oximetric recording

    Microsoft Academic Search

    C. ZAMARRÓN; P. V. ROMERO; F. GUDE; A. AMARO; J. R. RODRIGUEZ

    2001-01-01

    Using heart rate spectral analysis of nocturnal pulse oximetry, we prospectively evaluated the utility of this methodology in patients clinically suspected of having obstructive sleep apnoea (OSA). A hundred and ninety-seven outpatients referred with symptoms compatible with the diagnosis of OSA were studied. All participants had nocturnal pulse oximetry performed simultaneously with conventional polysomnography. Power density of heart rate obtained

  9. A biomedical entertainment platform design based on musical rhythm characteristics and heart rate variability (HRV)

    Microsoft Academic Search

    Yu-chieh Huang; Shih-hsiang Lin; Ching-yen Chien; Yi-cheng Chen; Lei-chun Chou; Sheng-chieh Huang; Ming-yie Jan

    2008-01-01

    Heart rate variability (HRV) is a measure of variations in the heart rate. Over the last 25 years, HRV analysis has became popular as a non-invasive research and clinical tool for indirectly investigating both cardiac and autonomic nervous system (ANS) function in both health and disease area. How the musical rhythmic characteristics, tempo and complexity, affect the performance of HRV

  10. Developmental Change in Feedback Processing as Reflected by Phasic Heart Rate Changes

    ERIC Educational Resources Information Center

    Crone, Eveline A.; Jennings, J. Richard; Van der Molen, Maurits W.

    2004-01-01

    Heart rate 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 heart rate slowed following negative feedback when stimuli were consistently mapped onto the left or right key…

  11. Evaluation of habitual physical activity from a week's heart rate monitoring in French school children

    Microsoft Academic Search

    G. Falgairette; O. Gavarry; T. Bernard; M. Hebbelinck

    1996-01-01

    Habitual physical activity (HPA) was studied in 30 boys and 34 girls aged 6–11 years. All the children performed a shuttle run test (SRT) to assess maximal heart frequency (f\\u000acmaxSRT) and to evaluate maximal oxygen uptake (VO2maxSRT). Heart rate (f\\u000ac) was measured continuously from Monday to Sunday, using a heart rate counter. The time spent at f\\u000ac

  12. Contactless and unobtrusive measurement of heart rate in home environment.

    PubMed

    Zakrzewski, Mari; Kolinummi, Arto; Vanhala, Jukka

    2006-01-01

    Current technology trends, such as ubiquitous computing and calm technology, call for novel unobtrusive sensors. The commonly used heart rate monitoring techniques require direct contact to the patient which makes the patient well aware of the sensors. In this paper, a novel method for detecting the distance of an approaching patient and for measuring his or her heart rate with a microwave Doppler radar is presented. This enables a truly non-contact and unobtrusive measurement. In addition, the measurement can be performed even through thick clothing. Furthermore, the patient does not need to be aware of being monitored since the method enables measurement to be started automatically as the patient approaches the sensor. PMID:17946492

  13. gHRV: Heart rate variability analysis made easy.

    PubMed

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

    2014-08-01

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

  14. Predicting rate of oxygen consumption from heart rate while little penguins work, rest and play

    E-print Network

    Schluter, Dolph

    Predicting rate of oxygen consumption from heart rate while little penguins work, rest and play J 2006; accepted 16 June 2006 Available online 21 June 2006 Abstract The relationship between heart rate-ranging animals. © 2006 Elsevier Inc. All rights reserved. Keywords: Penguin; Energetics; Heart rate; Exercise

  15. Characteristics of maternal heart rate patterns during labor and delivery

    Microsoft Academic Search

    Dan J Sherman; Eugenia Frenkel; Yaffa Kurzweil; Anna Padua; Shlomo Arieli; Murat Bahar

    2002-01-01

    OBJECTIVE:To find patterns characteristic of maternal heart rates recorded by an electronic fetal monitor and compare them with concomitant fetal heart rate (FHR) patterns.METHODS:Maternal heart rates and FHRs during active labor and delivery were simultaneously recorded in 26 parturients with singleton pregnancies in vertex presentation. The FHRs were obtained by an external ultrasound transducer or via a spiral scalp electrode

  16. Particle Effects on Heart-Rate Regulation in Senescent Mice

    Microsoft Academic Search

    Clarke G. Tankersley; Matthew Campen; Alexis Bierman; Susan E. Flanders; Karl W. Broman; Richard Rabold

    2004-01-01

    Because epidemiology studies consistently identify the elderly at risk for air pollution-related morbidity and mortality, we developed a model of senescent-dependent susceptibility based on indices of physiological aging. In the current study, we hypothesized that heart-rate regulation during particulate matter (PM) exposure differs with senescence-dependent susceptibility owing to variation in autonomic nervous control. Heart rate (HR) and heart-rate variability (HRV)

  17. Statistical physics of human heart rate in health and disease

    Microsoft Academic Search

    Ken Kiyono; Yoshiharu Yamamoto; Zbigniew R. Struzik

    Complex phenomena know several benchmarks, or ’hard’ and to date unsatisfactorily understood problems. Human heart rate control\\u000a is such a complexity benchmark in biophysics, consistently defying full explanation. In our recent work, heart rate regulation\\u000a by the autonomic nervous system has been shown to display remarkable fundamental properties of scale-invariance of extreme\\u000a value statistics [1] in healthy heart rate fluctuations,

  18. Critical Scale Invariance in a Healthy Human Heart Rate

    NASA Astrophysics Data System (ADS)

    Kiyono, Ken; Struzik, Zbigniew R.; Aoyagi, Naoko; Sakata, Seiichiro; Hayano, Junichiro; Yamamoto, Yoshiharu

    2004-10-01

    We demonstrate the robust scale-invariance in the probability density function (PDF) of detrended healthy human heart rate increments, which is preserved not only in a quiescent condition, but also in a dynamic state where the mean level of the heart rate is dramatically changing. This scale-independent and fractal structure is markedly different from the scale-dependent PDF evolution observed in a turbulentlike, cascade heart rate model. These results strongly support the view that a healthy human heart rate is controlled to converge continually to a critical state.

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

    ERIC Educational Resources Information Center

    Buck, Marilyn M.

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

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

    Microsoft Academic Search

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

    1993-01-01

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

  1. ARTiiFACT: a tool for heart rate artifact processing and heart rate variability analysis

    Microsoft Academic Search

    Tobias Kaufmann; Stefan Sütterlin; Stefan M. Schulz; Claus Vögele

    The importance of appropriate handling of artifacts in interbeat interval (IBI) data must not be underestimated. Even a single\\u000a artifact may cause unreliable heart rate variability (HRV) results. Thus, a robust artifact detection algorithm and the option\\u000a for manual intervention by the researcher form key components for confident HRV analysis. Here, we present ARTiiFACT, a software\\u000a tool for processing electrocardiogram

  2. Fish consumption is associated with lower heart rates

    Microsoft Academic Search

    Jean Dallongeville; John Yarnell; P Ducimetiere

    2004-01-01

    Background—Fish consumption decreases risk of sudden death. The goal of the present study was to assess the relationship between fish consumption and heart rate. Methods and Results—A cross-sectional analysis was conducted of 9758 men, age 50 to 59 years, without coronary heart disease (CHD) who were recruited in France and Belfast, Ireland, from 1991 to 1993. Heart rate and CHD

  3. Design and development of a heart rate measuring device using fingertip

    Microsoft Academic Search

    M. M. A. Hashem; R. Shams; M. A. Kader; M. A. Sayed

    2010-01-01

    In this paper, we presented the design and development of a new integrated device for measuring heart rate using fingertip to improve estimating the heart rate. As heart related diseases are increasing day by day, the need for an accurate and affordable heart rate measuring device or heart monitor is essential to ensure quality of health. However, most heart rate

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

    NASA Technical Reports Server (NTRS)

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

    2013-01-01

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

  5. Physical activity patterns defined by continuous heart rate monitoring

    Microsoft Academic Search

    N Armstrong; S Bray

    1991-01-01

    To investigate the physical activity patterns of British primary schoolchildren (mean (SD) 10.7 (0.3) years) the minute by minute heart rates of 67 boys and 65 girls were monitored continuously for three 12 hour periods during normal schooldays. In addition 39 children had their heart rates monitored during a 12 hour period on a Saturday. Few children experienced the volume

  6. A Nonparametric Approach to QT Interval Correction for Heart Rate

    Microsoft Academic Search

    Duolao Wang; Yin Bun Cheung; Radivoj Arezina; Jorg Taubel; Alan John Camm

    2010-01-01

    We propose to use generalized additive models to fit the relationship between QT interval and RR (RR = 60\\/heart rate), and develop two new methods for correcting the QT for heart rate: the linear additive model and log-transformed linear additive model. The proposed methods are compared with six commonly used parametric models that were used in four clinical trial data sets and

  7. Characteristics of Resonance in Heart Rate Variability Stimulated by Biofeedback

    Microsoft Academic Search

    Evgeny G. Vaschillo; Bronya Vaschillo; Paul M. Lehrer

    2006-01-01

    As we previously reported, resonant frequency heart rate variability biofeedback increases baroreflex gain and peak expiratory flow in healthy individuals and has positive effects in treatment of asthma patients. Biofeedback readily produces large oscillations in heart rate, blood pressure, vascular tone, and pulse amplitude via paced breathing at the specific natural resonant frequency of the cardiovascular system for each individual.

  8. Behavioural correlation of heart rate changes in family dogs

    Microsoft Academic Search

    Katalin Maros; Antal Dóka; Ádám Miklósi

    2008-01-01

    Fourteen dogs (7 males and 7 females) were tested for their heart rate (HR) and heart rate variability (HRV) responses in different activities and environmental challenges while their movement was controlled. First, we wanted to compare the dogs’ cardiac responses in different body positions (lying, sitting and standing) and during slow walking to reveal their possible influence on HR and

  9. HEART RATE VARIABILITY AS DETERMINISM WITH JUMP STOCHASTIC PARAMETERS

    E-print Network

    Bollt, Erik

    1. Introduction. Modeling the behavior of human cardiovascular system is an interest- ing problem, AND ERIK BOLLT§ Abstract. We use measured heart rate information (RR intervals) to develop a one with persistence which causes the heart rate and rhythm system to wander about a bifurcation point. We propose

  10. Using Target Heart-Rate Zones in Your Class

    ERIC Educational Resources Information Center

    Gilbert, Jennie A.

    2005-01-01

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

  11. Heart-Rate and Immersion in a First Person Simulation

    Microsoft Academic Search

    Michael Barlow; Edward Lewis; Jason Keir

    The paper examines the physiological response - as manifest as heart rate changes - and subjective impressions of presence, of a group of players of 1st Person Simulations. Varied experimental factors include two different simulations - VBS1 and Joint Ops: Typhoon Rising, solo and multi-player team play, and different types of scenarios. Across the population heart rate increase from resting

  12. Assessing resting heart rate in adolescents: determinants and correlates

    Microsoft Academic Search

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

    2002-01-01

    The aim of this study was to evaluate the distribution of resting heart rate and its biological and environmental determinants in adolescents. The study was cross- sectional and the population consisted of 2230 children and adolescents, age range 12–18 years, enrolled randomly from state schools in Turin, Italy. In all participants the following parameters were evaluated: heart rate, blood pressure

  13. Effect of suprachiasmatic lesions on diurnal heart rate rhythm in the rat

    NASA Technical Reports Server (NTRS)

    Saleh, M. A.; Winget, C. M.

    1977-01-01

    Heart rate 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 heart rate and locomotor activity was continued for ten days. SCN-lesioned rats showed no significant diurnal fluctuation in heart rate, 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 heart rate in the rat.

  14. Heart rate values for beaver, mink and muskrat.

    PubMed

    Gilbert, F F; Gofton, N

    1982-01-01

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

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

    ERIC Educational Resources Information Center

    Ackerly, Spafford C.

    2001-01-01

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

  16. An improved method for adjusting the QT interval for heart rate (the Framingham Heart Study)

    Microsoft Academic Search

    Alex Sagie; Martin G. Larson; Robert J. Goldberg; James R. Bengtson; Daniel Levy

    1992-01-01

    Several formulas have been proposed to adjust the QT interval for heart rate, 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 heart rate QT

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

    NASA Astrophysics Data System (ADS)

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

    During everyday life, gravity constantly stresses the human circulation by diminishing venous return in the upright position. This induces baroreflex-mediated cardiovascular adjustments that are aimed to prevent the blood pressure from falling. In weightlessness, gravitational pressure gradients do not arise in the circulation so that baroreflex function remains chronically unchallenged. This may contribute to the development of post spaceflight orthostatic intolerance. The purpose of this study was to evaluate respiratory modulation and baroreflex control of heart rate after a week of weightlessness in space. We tested the hypothesis that cardiovascular control in space will be similar to the baseline supine condition on Earth. We studied nine male cosmonauts during seven different space missions aboard the ISS (age 40 - 52 yrs, height 1.69 - 1.85 m, weight 67 - 90 kg). Data collection was performed between 30 and 45 days before launch in the standing and supine positions, and after 8 days in space. Cosmonauts were carefully trained to perform in-flight data collection by themselves. They were instructed to pace their breathing to a fixed rate of 12 breaths per minute (0.2 Hz) for a total duration of 3 minutes. The electrocardiogram and beat-by-beat finger arterial blood pressure were recorded at 1-kHz sample rate. Respiratory rate was evaluated using an abdominal pressure sensor. We used power spectral analysis to calculate respiratory sinus arrhythmia (RSA) as well as the low-frequency (0.04 - 0.15 Hz) powers of spontaneous oscillations in heart rate and systolic blood pressure. Baroreflex sensitivity (BRS) was estimated in the time domain using cross-correlation analysis. As expected, there was a rise in heart rate upon assuming the standing position before space- flight (59 ± 6 to 79 ± 11 beats per min; p ¡ 0.001). This was accompanied by an increase in mean arterial blood pressure (84 ± 6 to 93 ± 6 mmHg; p ¡ 0.001). Standing up further induced a marked increase in the low-frequency powers of systolic blood pressure oscillations (8 ± 7 to 17 ± 11 mmHg2; p = 0.018), whereas those in heart rate 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, heart rate (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 heart rate (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.

  18. An Examination of the Relationship Between Resting Heart Rate Variability and Heart Rate Reactivity to a Mental Arithmetic Stressor

    Microsoft Academic Search

    Christopher F. Sharpley; Peter Kamen; Maria Galatsis; Rod Heppel; Charles Veivers; Kim Claus

    2000-01-01

    Resting heart rate 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 heart rate reactivity to a stressor task have also been suggested as indicating increased risk of CVD via

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

    Microsoft Academic Search

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

    2001-01-01

    In order to assess the relative influence of age, resting heart rate (HR) and sedentary life style, heart rate variability (HRV) was studied in two different groups. The young group (YG) consisted of 9 sedentary subjects aged 15 to 20 years (YG-S) and of 9 nonsedentary volunteers (YG-NS) also aged 15 to 20. The elderly sedentary group (ESG) consisted of

  20. Thermal Acclimation of Heart Rates in Reptilian Embryos

    PubMed Central

    Du, Wei-Guo; Ye, Hua; Zhao, Bo; Warner, Daniel A.; Shine, Richard

    2010-01-01

    In many reptiles, the thermal regimes experienced by eggs in natural nests vary as a function of ambient weather and location, and this variation has important impacts on patterns of embryonic development. Recent advances in non-invasive measurement of embryonic heart rates allow us to answer a long-standing puzzle in reptilian developmental biology: Do the metabolic and developmental rates of embryos acclimate to local incubation regimes, as occurs for metabolic acclimation by post-hatching reptiles? Based on a strong correlation between embryonic heart rate and oxygen consumption, we used heart rates as a measure of metabolic rate. We demonstrate acclimation of heart rates relative to temperature in embryos of one turtle, one snake and one lizard species that oviposit in relatively deep nests, but found no acclimation in another lizard species that uses shallow (and hence, highly thermally variable) nests. Embryonic thermal acclimation thus is widespread, but not ubiquitous, within reptiles. PMID:21179473

  1. Eur Heart J. Author manuscript History of coronary heart disease and cognitive performance in midlife: the

    E-print Network

    Paris-Sud XI, Université de

    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

  2. Heart rate and cardiac rhythm relationships with bisoprolol benefit in chronic heart failure in CIBIS II trial

    Microsoft Academic Search

    Philippe Lechat; Jean-Sébastien Hulot; A Mallet

    2001-01-01

    Background— b-Blockade-induced benefit in heart failure (HF) could be related to baseline heart rate and treatment- induced heart rate reduction, but no such relationships have been demonstrated. Methods and Results—In CIBIS II, we studied the relationships between baseline heart rate (BHR), heart rate changes at 2 months (HRC), nature of cardiac rhythm (sinus rhythm or atrial fibrillation), and outcomes (mortality

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

    PubMed

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

    2014-01-01

    Chronic insomnia is highly prevalent in the general population, provoking personal distress and increased risk for psychiatric and medical disorders. Autonomic hyper-arousal could be a pathogenic mechanism of chronic primary insomnia. The aim of this study was to investigate autonomic activity in patients with chronic primary insomnia by means of heart rate variability (HRV) analysis. Eighty-five consecutive patients affected by chronic primary insomnia were enrolled (38 men and 47 women; mean age: 53.2 ± 13.6). Patients were compared with a control group composed of 55 healthy participants matched for age and gender (23 men and 32 women; mean age: 54.2 ± 13.9). Patients underwent an insomnia study protocol that included subjective sleep evaluation, psychometric measures, and home-based polysomnography with evaluation of HRV in wake before sleep, in all sleep stages, and in wake after final awakening. Patients showed modifications of heart rate and HRV parameters, consistent with increased sympathetic activity, while awake before sleep and during Stage-2 non-REM sleep. No significant differences between insomniacs and controls could be detected during slow-wave sleep, REM sleep, and post-sleep wake. These results are consistent with the hypothesis that autonomic hyper-arousal is a major pathogenic mechanism in primary insomnia, and confirm that this condition is associated with an increased cardiovascular risk. PMID:24128278

  4. Phase Transition in a Healthy Human Heart Rate

    NASA Astrophysics Data System (ADS)

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

    2005-07-01

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

  5. Long-range dependencies in heart rate signals—revisited

    Microsoft Academic Search

    Danuta Makowiec; Aleksandra Dudkowska; Andrzej Rynkiewicz; Marcin Zwierz

    2006-01-01

    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 heart rate is a mixture

  6. Heart rates in the captive, free-ranging beaver.

    PubMed

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

    1988-01-01

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

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

    NASA Technical Reports Server (NTRS)

    Hooker, John C.

    1990-01-01

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

  8. Heart rate turbulence during acute alcohol withdrawal syndrome

    Microsoft Academic Search

    Thomas Jochum; Steffen Schulz; Marion Schein; Rico Schröder; Andreas Voss; Karl-Jürgen Bär

    BackgroundAlcohol withdrawal syndrome is associated with an increased incidence of cardiac arrhythmias and sudden cardiac death. Heart rate turbulence (HRT) parameters were applied during withdrawal to estimate cardiac regulation during treatment with clomethiazole.

  9. Heart rate responses to parental behavior in depressed adolescents.

    PubMed

    Allen, Nicholas B; Kuppens, Peter; Sheeber, Lisa B

    2012-04-01

    In order to more fully understand the abnormalities in emotional responding associated with adolescent depression we examined clinically depressed and non-depressed adolescents' physiological responses to their parents' negative emotional behavior, as indexed by their heart rate responses to parental angry and dysphoric behavior during laboratory-based interactions. Maternal angry and dysphoric behavior predicted heart rate deceleration amongst non-depressed adolescents, a response that was not observed in depressed adolescents. Fathers' angry behavior predicted significant heart rate acceleration in depressed (but not non-depressed) adolescents, whereas fathers' dysphoric behavior predicted heart rate deceleration amongst depressed but not amongst non-depressed adolescents. These findings are interpreted within the framework of orienting and defense cardiac responses, and suggest that reactivity in adolescent depression is characterized by the absence of a normative orienting response toward aversive maternal behaviors, and a defensive physiological response to aggressive paternal behavior. PMID:22391522

  10. Instantaneous heart rate: Should RR-intervals be resampled?

    Microsoft Academic Search

    M. Potter; W. Kinsner

    2008-01-01

    RR-interval sequences (tachograms) represent heart rate variability discretely. When time series representations of instantaneous heart rate (IHR) are required, tachograms are often resampled into a time series. This paper demonstrates that traditional RR-interval resampling is often inconsistent with the time domain constraints of the tachogram. A general technique, called frequency-modulated phase-interpolation (FMPI), is presented that preserves the time domain constraints.

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

    NASA Astrophysics Data System (ADS)

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

    2009-07-01

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

  12. Heart Rate Variability: Measures and Models

    E-print Network

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

    2000-08-07

    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.

  13. Heart Physiology Worksheet Table 1. Pulse Rate Data

    E-print Network

    Loughry, Jim

    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

  14. Effect of energy drink dose on exercise capacity, heart rate recovery and heart rate variability after high-intensity exercise

    PubMed Central

    An, Sang Min; Park, Jong Suk; Kim, Sang Ho

    2014-01-01

    [Purpose] The purpose of this research was to investigate the effects of exercise capacity, heart rate recovery and heart rate variability after high-intensity exercise on caffeine concentration of energy drink. [Methods] The volunteers for this study were 15 male university student. 15 subjects were taken basic physical examinations such as height, weight and BMI before the experiment. Primary tests were examined of VO2max per weight of each subjects by graded exercise test using Bruce protocol. Each of five subject was divided 3 groups (CON, ECG?, ECG?) by matched method based on weight and VO2max per weight what gained of primary test for minimize the differences of exercise capacity and ingestion of each groups. For the secondary tests, the groups of subjects were taken their materials before and after exercise as a blind test. After the ingestion, subjects were experimented on exercise test of VO2max 80% by treadmill until the all-out. Heart rate was measured by 1minute interval, and respiratory variables were analyzed VO2, VE, VT, RR and so on by automatic respiratory analyzer. And exercise exhaustion time was determined by stopwatch. Moreover, HRV was measured after exercise and recovery 3 min. [Results] Among the intake groups, ECG? was showed the longest of exercise exhaustion time more than CON group (p = .05). Result of heart rate during exercise according to intake groups, there was significant differences of each time (p < .001), however, not significant differences of each groups and group verse time (p > .05). Result of RPE during exercise according to intake groups, there was significant differences of each time (p < .001), however, not significant differences of each groups and group verse time (p > .05). [Conclusion] In conclusion, EDG? showed the significant increase of exercise exhaustion time more than CON group (p=.05) and not significant differences in HR, RPE, RER, HRV, HRR, blood pressure (p > .05). Therefore, 2.5 mg/kg-1 ingestion of energy drink might be positive effect to increase exercise performance capacity without side-effect in cardiovascular disease. PMID:25566437

  15. Nearest-neighbor based wavelet entropy rate measures for intrapartum fetal heart rate variability.

    PubMed

    Spilka, J; Roux, S G; Garnier, N B; Abry, P; Goncalves, P; Doret, M

    2014-01-01

    The interpretation and analysis of intrapartum fetal heart rate (FHR), enabling early detection of fetal acidosis, remains a challenging signal processing task. The ability of entropy rate measures, amongst other tools, to characterize temporal dynamics of FHR variability and to discriminate non-healthy fetuses has already been massively investigated. The present contribution aims first at illustrating that a k-nearest neighbor procedure yields estimates for entropy rates that are robust and well-suited to FHR variability (compared to the more commonly used correlation-integral algorithm). Second, it investigates how entropy rates measured on multiresolution wavelet and approximation coefficients permit to improve classification performance. To that end, a supervised learning procedure is used, that selects the time scales at which entropy rates contribute to discrimination. Significant conclusions are obtained from a high quality scalp electrode database of nearly two thousands subjects collected in a French public university hospital. PMID:25570576

  16. Flight Modes in Migrating European Bee-Eaters: Heart Rate May Indicate Low Metabolic Rate during Soaring

    E-print Network

    Nathan, Ran

    Flight Modes in Migrating European Bee-Eaters: Heart Rate 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: Heart Rate

  17. Heart Rate Variability Dynamics for the Prognosis of Cardiovascular Risk

    PubMed Central

    Ramirez-Villegas, Juan F.; Lam-Espinosa, Eric; Ramirez-Moreno, David F.; Calvo-Echeverry, Paulo C.; Agredo-Rodriguez, Wilfredo

    2011-01-01

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

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

    SciTech Connect

    Georgieva, A. E. [Nuffield Department of Obstetrics and Gynaecology, University of Oxford, Level 3 Women's Centre, John Radcliffe Hospital, Oxford OX3 9DU (United Kingdom); Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, Old Road Campus Research Building Oxford OX3 7DQ (United Kingdom); Payne, S. J. [Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, Old Road Campus Research Building Oxford OX3 7DQ (United Kingdom); Moulden, M.; Redman, C. W. G. [Nuffield Department of Obstetrics and Gynaecology, University of Oxford, Level 3 Women's Centre, John Radcliffe Hospital, Oxford OX3 9DU (United Kingdom)

    2010-10-25

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

  19. Effect of pacemaker rate-adaptation on 24h beat-to-beat heart rate and blood pressure profiles

    Microsoft Academic Search

    Raffaele Quaglione; Giovanni Calcagnini; Federica Censi; Mario Malavasi; Marco Raveggi; Gianluca Biancalana; Pietro Bartolini; Giuseppe Critelli

    2005-01-01

    Abstract,Aims,The aims,of the study,were,to evaluate,the 24-h beat-to-beat heart rate (RR) and,blood,pressure,changes,during closed,loop stimulation,(DDD- CLS) pacing,and,conventional,fixed rate DDD pacing,with respect,to spontaneous activity. Methods,We simultaneously,and,continuously,measured,beat-to-beat heart rate and blood pressure for 24 h in patients implanted with Inos,C (Biotronik GmbH, Berlin, Germany). A randomised cross-over comparison of DDD-CLS and DDD pacing was,performed,by short- and long-term analyses. Results Seventeen patients (10 males, aged

  20. Heart rate variability interventions for concussion and rehabilitation.

    PubMed

    Conder, Robert L; Conder, Alanna A

    2014-01-01

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

  1. The Use of Heart Rate Monitors in Physical Education

    ERIC Educational Resources Information Center

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

    2009-01-01

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

  2. Short-Term Heart Rate Variability Strongly Predicts Sudden Cardiac Death in Chronic Heart Failure Patients

    Microsoft Academic Search

    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

    Background—The predictive value of heart rate 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 Results—A multivariate survival model for the identification of sudden (presumably arrhythmic) death was developed with data from 202 consecutive patients referred

  3. Feedback control of heart rate during robotics-assisted treadmill exercise.

    PubMed

    Schindelholz, Matthias; Hunt, Kenneth J

    2012-01-01

    Robotics-assisted treadmill exercise has potential for cardiovascular rehabilitation of patients with miscellaneous neurological deficits. A novel approach is presented here which suggests using heart rate to define and control exercise intensity during robotics-assisted treadmill exercise. The work delineates the design and provides technical validation of the new method. A feedback structure in conjunction with a human-in-the-loop feedback for volitional control of mechanical work rate is proposed which provides automatic regulation of heart rate. A controller computes the target mechanical work rate based on target and actual heart rates. An analytical model-based method was used to design the controller. The overall feedback design process is technically validated through a test series with different control tasks including square-wave tracking, disturbance rejection, ramp tracking and an open loop test. The feedback method and the heart rate control provide close to nominal performance for square-wave and ramp reference tracking tasks below and above the anaerobic threshold, which was estimated by the V-slope method. The controllers provide robust and stable performance as verified by calculation of the root mean square error of the tracked heart rate at different effort levels as well as with the disturbance test. Further work is required to evaluate the robustness of the approach across a group of subjects including neurological patients to show the potential for clinical implementation and to achieve a positive effect for the cardiovascular status of patients. PMID:22735733

  4. Relationship between laboratory-measured variables and heart rate during an ultra-endurance triathlon.

    PubMed

    Laursen, Paul B; Knez, Wade L; Shing, Cecilia M; Langill, Robert H; Rhodes, Edward C; Jenkins, David G

    2005-10-01

    The aim of the present study was to examine the relationship between the performance heart rate during an ultra-endurance triathlon and the heart rate corresponding to several demarcation points measured during laboratory-based progressive cycle ergometry and treadmill running. Less than one month before an ultra-endurance triathlon, 21 well-trained ultra-endurance triathletes (mean +/- s: age 35 +/- 6 years, height 1.77 +/- 0.05 m, mass 74.0 +/- 6.9 kg, = 4.75 +/- 0.42 l x min(-1)) performed progressive exercise tests of cycle ergometry and treadmill running for the determination of peak oxygen uptake (VO2peak), heart rate corresponding to the first and second ventilatory thresholds, as well as the heart rate deflection point. Portable telemetry units recorded heart rate at 60 s increments throughout the ultra-endurance triathlon. Heart rate during the cycle and run phases of the ultra-endurance triathlon (148 +/- 9 and 143 +/- 13 beats x min(-1) respectively) were significantly (P < 0.05) less than the second ventilatory thresholds (160 +/- 13 and 165 +/- 14 beats x min(-1) respectively) and heart rate deflection points (170 +/- 13 and 179 +/- 9 beats x min(-1) respectively). However, mean heart rate during the cycle and run phases of the ultra-endurance triathlon were significantly related to (r = 0.76 and 0.66; P < 0.01), and not significantly different from, the first ventilatory thresholds (146 +/- 12 and 148 +/- 15 beats x min(-1) respectively). Furthermore, the difference between heart rate during the cycle phase of the ultra-endurance triathlon and heart rate at the first ventilatory threshold was related to marathon run time (r = 0.61; P < 0.01) and overall ultra-endurance triathlon time (r = 0.45; P < 0.05). The results suggest that triathletes perform the cycle and run phases of the ultra-endurance triathlon at an exercise intensity near their first ventilatory threshold. PMID:16194987

  5. Classification of heart rate variability in patients with mild hypertension.

    PubMed

    Raymond, B; Taverner, D; Nandagopal, D; Mazumdar, J

    1997-12-01

    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 heart rate 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

  6. Prediction of Heart Rates on a Ropes Course from Simple Physical Measures. Research Update.

    ERIC Educational Resources Information Center

    Priest, Simon; Montelpare, William

    1995-01-01

    This study identified the highest heart rates attained on a ropes course for a corporate population; examined relationships between highest heart rate and other physical measures (basal heart rate, blood pressure, height, weight, body girths, cholesterol, maximum number of pushups, and heart rate after brisk walk); and developed an equation for…

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

    E-print Network

    Glass, Leon

    Introduction to Controversial Topics in Nonlinear Science: Is the Normal Heart Rate Chaotic? Leon. The first of these deals with the dynamical characterization of human heart rate variability. We asked authors to respond to the following questions: Is the normal heart rate chaotic? If the normal heart rate

  8. Heart rate strain in cable hauler choker setters in New Zealand logging operations

    Microsoft Academic Search

    Patrick M Kirk; Mark J. M Sullman

    2001-01-01

    This study examined the physical strain experienced by cable hauler choker setters, and the applicability of heart rate indices for measuring physical strain in commercial forest harvesting operations in New Zealand. The heart rate of four choker setters were recorded continuously throughout the working day and applied to heart rate indices. Based on the relative heart rate at work (%HRR),

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

    PubMed

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

    2015-03-01

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

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

    NASA Astrophysics Data System (ADS)

    Wessel, Niels; Riedl, Maik; Kurths, Jürgen

    2009-06-01

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

  11. Model for complex heart rate dynamics in health and diseases

    NASA Astrophysics Data System (ADS)

    Kotani, Kiyoshi; Struzik, Zbigniew R.; Takamasu, Kiyoshi; Stanley, H. Eugene; Yamamoto, Yoshiharu

    2005-10-01

    A physiologically motivated, dynamical model of cardiovascular autonomic regulation is shown to be capable of generating long-range correlated and multifractal heart rate. Virtual disease simulations are carried out systematically to account for the disease-induced relative dysfunction of the parasympathetic and the sympathetic branches of the autonomic control. Statistical agreement of the simulation results with those of real life data is reached, suggesting the possible use of the model as a state-of-the-art basis for further understanding of the physiological correlates of complex heart rate dynamics.

  12. Robust efficient estimation of heart rate pulse from video

    PubMed Central

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

    2014-01-01

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

  13. Modeling baroreflex regulation of heart rate during orthostatic stress.

    PubMed

    Olufsen, Mette S; Tran, Hien T; Ottesen, Johnny T; Lipsitz, Lewis A; Novak, Vera

    2006-11-01

    During orthostatic stress, arterial and cardiopulmonary baroreflexes play a key role in maintaining arterial pressure by regulating heart rate. This study presents a mathematical model that can predict the dynamics of heart rate regulation in response to postural change from sitting to standing. The model uses blood pressure measured in the finger as an input to model heart rate dynamics in response to changes in baroreceptor nerve firing rate, sympathetic and parasympathetic responses, vestibulo-sympathetic reflex, and concentrations of norepinephrine and acetylcholine. We formulate an inverse least squares problem for parameter estimation and successfully demonstrate that our mathematical model can accurately predict heart rate dynamics observed in data obtained from healthy young, healthy elderly, and hypertensive elderly subjects. One of our key findings indicates that, to successfully validate our model against clinical data, it is necessary to include the vestibulo-sympathetic reflex. Furthermore, our model reveals that the transfer between the nerve firing and blood pressure is nonlinear and follows a hysteresis curve. In healthy young people, the hysteresis loop is wide, whereas, in healthy and hypertensive elderly people, the hysteresis loop shifts to higher blood pressure values, and its area is diminished. Finally, for hypertensive elderly people, the hysteresis loop is generally not closed, indicating that, during postural change from sitting to standing, baroreflex modulation does not return to steady state during the first minute of standing. PMID:16793939

  14. A Systematic Review and Meta-analysis of Studies Comparing Readmission Rates and Mortality Rates in Patients With Heart Failure

    Microsoft Academic Search

    Femida H. Gwadry-Sridhar; Virginia Flintoft; Douglas S. Lee; Hui Lee; Gordon H. Guyatt

    2004-01-01

    Background: Heart failure is the leading cause of hos- pitalization and readmission in many hospitals world- wide. We performed a meta-analysis to evaluate the ef- fectivenessofmultidisciplinaryheartfailuremanagement programs on hospital admission rates. Methods: We identified studies through an electronic search and mortality using 8 distinct methods. Eligible studies met the following criteria: (1) randomized con- trolled clinical trials of adult inpatients

  15. Matter Over Mind: A Randomised-Controlled Trial of Single-Session Biofeedback Training on Performance Anxiety and Heart Rate Variability in Musicians

    PubMed Central

    Wells, Ruth; Outhred, Tim; Heathers, James A. J.; Quintana, Daniel S.; Kemp, Andrew H.

    2012-01-01

    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

  16. Autonomic Dysfunction and Risk Stratification Assessed from Heart Rate Pattern

    PubMed Central

    Günther, A; Witte, O.W; Hoyer, D

    2010-01-01

    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 Heart Rate Variability (HRV) analysis and HRV monitoring will be described in detail in this chapter. The grown importance of these easily obtainable heart rate 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

  17. Effects of an SCBA on breathing pattern, gas exchange, and heart rate during exercise.

    PubMed

    Louhevaara, V; Smolander, J; Tuomi, T; Korhonen, O; Jaakkola, J

    1985-03-01

    The effects of a pressure demand-type self-contained breathing apparatus (SCBA) (total weight, 15.5 kg) on breathing pattern, gas exchange, and heart rate were studied in 13 firemen. The subjects performed sequential progressive exercise tests on a treadmill both without and with an SCBA. The use of an SCBA consistently limited tidal volume. During submaximal exercise oxygen consumption and heart rate increased remarkably more with the SCBA than without it. Four subjects reached their maximal heart rate with the SCBA. Their mean ventilation rate was 68% and oxygen consumption was 83% of the maximal values attained without the SCBA. The shoulder harness of the heavy SCBA prevented free motion of the thorax, affecting the regulation of breathing, and thus seriously disturbed ventilation and gas exchange, particularly at heavier exercise levels. PMID:3981278

  18. Spectral analysis of heart rate variability in premature infants

    Microsoft Academic Search

    Morarji Peeseya; Harel Rosen; Mark Hiatt; Thomas Hegyi

    We studied the effect of gestational age, birth weight, postmenstrual age and selected neonatal morbidities on the heart rate power spectra in preterm infants (birth weight 1075 (840, 1230) grams, gestational age 27 (26, 30) weeks). Age at testing was 6 (3, 11) days. Birth weight, gestational age and postmenstrual age were positively correlated with low frequency power (0.03- 0.39

  19. Diving Heart Rate Development in Postnatal Harbour Seals, Phoca vitulina

    E-print Network

    Burns, Jennifer M.

    9 Diving Heart Rate Development in Postnatal Harbour Seals, Phoca vitulina Danielle K. Greaves1, Anchorage, Alaska 99508 Accepted 5/6/04 ABSTRACT Harbour seals, Phoca vitulina, dive from birth, providing of Chicago. All rights reserved. 1522-2152/2005/7801-3102$15.00 Introduction Foetal seals demonstrate

  20. Robust sensor fusion of unobtrusively measured heart rate.

    PubMed

    Wartzek, Tobias; Brüser, Christoph; Walter, Marian; Leonhardt, Steffen

    2014-03-01

    Contactless vital sign measurement technologies often have the drawback of severe motion artifacts and periods in which no signal is available. However, using several identical or physically different sensors, redundancy can be used to decrease the error in noncontact heart rate estimation, while increasing the time period during which reliable data are available. In this paper, we show for the first time two major results in case of contactless heart rate measurements deduced from a capacitive ECG and optical pulse signals. First, an artifact detection is an essential preprocessing step to allow a reliable fusion. Second, the robust but computationally efficient median already provides good results; however, using a Bayesian approach, and a short time estimation of the variance, best results in terms of difference to reference heart rate and temporal coverage can be achieved. In this paper, six sensor signals were used and coverage increased from 0-90% to 80-94%, while the difference between the estimated heart rate and the gold standard was less than ±2 BPM. PMID:24608065

  1. Hierarchical structure in healthy and diseased human heart rate variability

    NASA Astrophysics Data System (ADS)

    Ching, Emily S.; Lin, D. C.; Zhang, C.

    2004-05-01

    It is shown that the healthy and diseased human heart rate variability (HRV) possesses a hierarchical structure of the She-Leveque (SL) form. This structure, first found in measurements in turbulent fluid flows, implies further details in the HRV multifractal scaling. The potential of diagnosis is also discussed based on the characteristics derived from the SL hierarchy.

  2. Analysis of Heart Rate Variability in Space Medicine

    Microsoft Academic Search

    R. M. Baevskii

    2002-01-01

    Space medicine was one of the first fields of science and practice to use the analysis of the heart rate variability (HRV) for obtaining new scientific information and solving the tasks of exercising medical control over humans working under extreme conditions. The theoretical basis of HRV analysis and different approaches to the assessment of the data obtained are presented in

  3. Segmentation of heart rate variability in different physical activities

    Microsoft Academic Search

    H. L. Chan; C. H. Lin; Y. L. Ko

    2003-01-01

    Heart rate variability is due to the interaction of sympathetic and parasympathetic nervous system. The spectral analysis of HRV provides a noninvasive probe to assess the function of the autonomic nervous system. The recording of physiological signals on free-moving subjects provides a useful tool to evaluate the autonomic states in the daily activities, but the information of activities is lack

  4. Robust estimation of fetal heart rate variability using Doppler ultrasound

    Microsoft Academic Search

    Kumari L. Fernando; V. John Mathews; Michael W. Varner; Edward B. Clark

    2003-01-01

    This paper presents a new measure of heart rate 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

  5. Coping with limitations of Doppler ultrasound fetal heart rate monitors

    Microsoft Academic Search

    Janusz Jezewski; J. Wrobel; K. Horoba; S. Graczyk; A. Gacek

    1995-01-01

    The most common noninvasive method of measuring fetal heart rate (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

  6. Robust estimation of fetal heart rate variability using Doppler ultrasound

    Microsoft Academic Search

    K. L. Fernando; V. J. Mathews; M. W. Varner; E. B. Clark

    2003-01-01

    Heart rate 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

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

    ERIC Educational Resources Information Center

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

    2012-01-01

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

  8. Novel approach for fetal heart rate classification introducing grammatical evolution

    Microsoft Academic Search

    George Georgoulas; Dimitris Gavrilis; Ioannis G. Tsoulos; Chrysostomos Stylios; João Bernardes; Peter P. Groumpos

    2007-01-01

    Fetal heart rate (FHR) variations reflect the level of oxygenation and blood pressure of the fetus. Electronic Fetal Monitoring (EFM), the continuous monitoring of the FHR, was introduced into clinical practice in the late 1960s and since then it has been considered as an indispensable tool for fetal surveillance. However, EFM evaluation and its merit is still an open field

  9. The quality of intrapartum fetal heart rate monitoring

    Microsoft Academic Search

    P. C. A. M Bakker; G. J Colenbrander; A. A Verstraeten; H. P Van Geijn

    2004-01-01

    Objective: To determine the quality of fetal heart rate (FHR) recordings during the first and second stage of labor by quantifying the amount of fetal signal loss in relation to the method of monitoring: external ultrasound or directly via a scalp electrode. Study Design: Analysis of 239 intrapartum recordings stored between 1 January 2001 and 1 July 2001 from consecutive

  10. Design of an FECG scalp electrode fetal heart rate monitor

    Microsoft Academic Search

    F. Bereksi Reguig; D. L. Kirk

    1996-01-01

    The design of a fetal heart rate (FHR) monitor using fetal electrocardiogram (FECG) scalp electrodes is described. It is shown that the design approach followed two stages: generation of FHR pulses at R-R intervals and FHR computation. The former uses a simple hardware approach for QRS detection and R-wave enhancement, while the latter requires a software implementation in order to

  11. Effect of Phototherapy on Neonatal Heart Rate Variability and Complexity

    Microsoft Academic Search

    Amir Weissman; Elad Berkowitz; Tatiana Smolkin; Shraga Blazer

    2009-01-01

    Background: Phototherapy is a common mode of treatment for neonatal hyperbilirubinemia. However, phototherapy has been reported to alter cardiovascular function by causing increased peripheral blood flow, diminished cardiac output and increased sympathetic activity that may be of concern particularly in sick or premature newborns. The effects of phototherapy on the autonomic nervous system modulation of heart rate in term neonates

  12. Heart Rate and Stress in a College Setting

    ERIC Educational Resources Information Center

    Elwess, Nancy L.; Vogt, F. Daniel

    2005-01-01

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

  13. Heart Rate Variability During Early Adaptation to Space

    NASA Technical Reports Server (NTRS)

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

    1994-01-01

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

  14. The physiological determinants and risk correlations of elevated heart rate

    Microsoft Academic Search

    Paolo Palatini; Stevo Julius

    1999-01-01

    A number of studies have shown that fast heart rate is associated with high blood pressure and metabolic disturbances, and that it is a strong precursor of hypertension, atherosclerosis, and cardiovascular events. Subjects with tachycardia often also exhibit increased plasma insulin, overweight, and higher hematocrit. These relationships have been observed also in the elderly and among hypertensive individuals and have

  15. Heart rate turbulence analysis in female patients with fibromyalgia

    PubMed Central

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

    2015-01-01

    OBJECTIVE: Fibromyalgia is characterized by diffuse musculoskeletal pain and discomfort. There are several reports regarding autonomic nervous system dysfunction in patients with fibromyalgia. Heart rate turbulence is expressed as ventriculophasic sinus arrhythmia and has been considered to reflect cardiac autonomic activity. Heart rate turbulence has been shown to be an independent and powerful predictor of sudden cardiac death in various cardiac abnormalities. The aim of this study is to determine whether heart rate turbulence is changed in female patients with fibromyalgia compared with healthy controls. METHODS: Thirty-seven female patients (mean age, 40±11 years) with fibromyalgia, and 35 age- and sex-matched healthy female control subjects (mean age, 42±9 years) were included. Twenty-four hours of ambulatory electrocardiography recordings were collected for all subjects, and turbulence onset and turbulence slope values were automatically calculated. RESULTS: The baseline clinical characteristics of the two groups were similar. There were no significant differences in turbulence onset and turbulence slope measures between patients and control subjects (turbulence onset: ?1.648±1.568% vs. ?1.582±1.436%, p???0.853; turbulence slope: 12.933±5.693 ms/RR vs. 13.639±2.505 ms/RR, p???0.508). Although body mass index was negatively correlated with turbulence slope (r????0.258, p???0.046), no significant correlation was found between body mass index and turbulence onset (r???0.228, p???0.054). CONCLUSION: To the best of our knowledge, this is the first study to evaluate heart rate turbulence in patients with fibromyalgia. It appears that heart rate turbulence parameters reflecting cardiac autonomic activity are not changed in female patients with fibromyalgia. PMID:26017798

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

    PubMed Central

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

    2014-01-01

    Background Sleep-disordered breathing (SDB) is associated with adverse outcomes in patients with chronic heart failure (CHF). Additionally, heart rate turbulence (HRT) reflects changes in the sinus cycle length of baroreceptor in response to hemodynamic fluctuations after ventricular premature beat. Recent studies have suggested that HRT as a marker of vagal activity has a predictive value of poor prognosis in CHF patients. However, little is known about the relationship between SDB and HRT in CHF patients. Methods and Results In this study, 75 patients with CHF were enrolled. We simultaneously performed Holter ECG during a 24-hr period and portable sleep monitoring at nighttime, and determined the respiratory disturbance index (RDI), HRT (turbulence onset (TO) and turbulence slope (TS)) during that 24-hr period. These patients were divided into two groups based on the presence of severe SDB: Group A (RDI?30, n?=?17) and Group B (RDI<30, n?=?58). TS was significantly lower in Group A than in Group B across the 24-hr period (nighttime: 3.6±1.1 vs. 6.9±1.3; daytime: 3.7±0.8 vs. 7.0±1.1; all-day: 3.5±0.7 vs. 6.7±0.9% ms/RR, P<0.05, respectively). TO did not differ between the two groups. Furthermore, there was a significant negative correlation between all-day TS and RDI (R?=?–0.257, P?=?0.027). Moreover, in the multiple regression analysis, RDI was an independent factor to determine all-day TS. Conclusions In patients with severe SDB, blunted TS was observed across 24 hours. These results suggest that SDB induce impairment of vagal activity across a 24-hour period and may be associated with poor prognosis in CHF patients. PMID:24968229

  17. Heart rate dynamics in doxorubicin-induced cardiomyopathy.

    PubMed

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

    2015-04-01

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

  18. The influence of mean heart rate on measures of heart rate variability as markers of autonomic function: a model study

    Microsoft Academic Search

    Hung-Wen Chiu; Ti-Ho Wang; Lu-Chou Huang; Han-Wen Tso; Tsair Kao

    2003-01-01

    Some studies have demonstrated that the assessments of autonomic activities from the alterations of heart rate variations (HRVs) after autonomic blockade and during exercise of high intensity by the spectral analysis of HRV seemed inconsistent with actual situation. The inconsistency is probably caused by the contributions of fluctuating magnitudes and mean levels of autonomic activities on HRV having not been

  19. Analysis of long term heart rate variability: methods, 1/f scaling and implications

    NASA Technical Reports Server (NTRS)

    Saul, J. P.; Albrecht, P.; Berger, R. D.; Cohen, R. J.

    1988-01-01

    The use of spectral techniques to quantify short term heart rate fluctuations on the order of seconds to minutes has helped define the autonomic contributions to beat-to-beat control of heart rate. We used similar techniques to quantify the entire spectrum (0.00003-1.0 Hz) of heart rate 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 heart rate time series was constructed at 3 Hz. Frequency analysis of the heart rate 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.

  20. Pulse transducer with artifact signal attenuator. [heart rate sensors

    NASA Technical Reports Server (NTRS)

    Cash, W. H., Jr.; Polhemus, J. T. (inventors)

    1980-01-01

    An artifact signal attenuator for a pulse rate sensor is described. The circuit for attenuating background noise signals is connected with a pulse rate transducer which has a light source and a detector for light reflected from blood vessels of a living body. The heart signal provided consists of a modulated dc signal voltage indicative of pulse rate. The artifact signal resulting from light reflected from the skin of the body comprises both a constant dc signal voltage and a modulated dc signal voltage. The amplitude of the artifact signal is greater and the frequency less than that of the heart signal. The signal attenuator circuit includes an operational amplifier for canceling the artifact signal from the output signal of the transducer and has the capability of meeting packaging requirements for wrist-watch-size packages.

  1. EATING OR SKIPPING BREAKFAST: EFFECTS ON RESTING EEG ACTIVITY AND HEART RATE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An adequate level of arousal is fundamental to efficient performance and cognitive functioning, and nutritional variables can influence arousal. The effects of morning nutrition on measures of arousal [EEG and heart rate (HR)] were studied in healthy right-handed children (8-11 yrs. old; IQ > 80) re...

  2. Microprocessor heart rate histogram recorder for ambulatory monitoring of daily physical activity

    Microsoft Academic Search

    D. L. Craig

    1981-01-01

    A microprocessor recorder for the generation of histograms of beat-to-beat heart rate during daily physical activity is described.\\u000a This device is intended for use in the assessment of the range of physical activities (energy expenditure) that can be performed\\u000a by patients with cardiovascular and respiratory disease.

  3. Miniature sensor for Doppler ultrasound fetal heart rate monitoring. Increased patient comfort and ergonomy in use

    Microsoft Academic Search

    B. Karlsson; D. Pourcelot; L. Pourcelot; M. Berson

    1996-01-01

    We have developed light weight miniature ultrasonic sensors for use in FHR (Fetal Heart Rate) 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

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

    Microsoft Academic Search

    Jerri Luiz Ribeiro; Caio S. Rosa; Rafael R. Baptist; Alvaro R. Oliveira

    The development of specific training designed to enhance physiological aspects of performance relies heavily on the availability of accurate and validity physiological data. In the combat sport of Wushu, katas are used to develop aerobic fitness. It is arguably important to assess and monitor heart rate (HR) and lactate (La) responses when designing effective training programs. The aim of this

  5. Relation between heart rate variability and training load in middle-distance runners

    Microsoft Academic Search

    Vincent PICHOT; Jean-Michel GASPOZ; Franck ENJOLRAS; Anestis ANTONIADIS; Pascal MININI; Thierry BUSSO

    2000-01-01

    V. PICHOT, F. ROCHE, J. M. GASPOZ, F. ENJOLRAS, A. ANTONIADIS, P. MININI, F. COSTES, T. BUSSO, J. R. LACOUR, and J. C. BARTHELEMY. Relation between heart rate variability and training load in middle-distance runners. Med. Sci. Sports Exerc., Vol. 32, No. 10, pp. 1729-1736, 2000. Purpose: Monitoring physical performance is of major importance in competitive sports. Indices commonly used,

  6. The rating of photovoltaic performance

    Microsoft Academic Search

    Keith Emery

    1999-01-01

    The electrical performance of photovoltaic (PV) cells, modules, and systems are rated in terms of their maximum electrical power with respect to a total irradiance, temperature, and spectral irradiance. The impact of the reference conditions, measurement procedures, and equipment on the performance rating is discussed

  7. Extraction of Heart Rate Variability from Smartphone Photoplethysmograms

    PubMed Central

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

    2015-01-01

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

  8. Extraction of heart rate variability from smartphone photoplethysmograms.

    PubMed

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

    2015-01-01

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

  9. Use of reversed regulation of work rate intensity by heart rate in testing physical fitness (CHR test)

    Microsoft Academic Search

    Pavel Stejskal; Richard Sup; Ivo Doležal; Jindriška Hejnová

    1993-01-01

    A method of testing endurance capacity and physical fitness (40?minute test) based on control of the test work rate by a defined heart rate (clamped heart rate [CHR] test) is proposed. This test was used on 26 men and 19 women with sedentary occupations, about half of whom had regular unorganized sporting activity. A subject's physiologic reaction to a heart

  10. Confronting a Cardiovascular System Model with Heart Rate and Blood Pressure Data

    E-print Network

    McSharry, Patrick E.

    Confronting a Cardiovascular System Model with Heart Rate and Blood Pressure Data PE McSharry1 fluctuations in the heart rate, blood pressure and rate of respiration. Its time evolution is governed this control mechanism and to explore the interactions between the heart rate and blood pressure. In this model

  11. Confronting a Cardiovascular System Model with Heart Rate and Blood Pressure Data

    E-print Network

    McSharry, Patrick E.

    Confronting a Cardiovascular System Model with Heart Rate and Blood Pressure Data PE McSharry 1 fluctuations in the heart rate, blood pressure and rate of respiration. Its time evolution is governed this control mechanism and to explore the interactions between the heart rate and blood pressure. In this model

  12. Abstract Despite the exponential growth in heart rate variability (HRV) research, the reproducibility

    E-print Network

    Abstract Despite the exponential growth in heart rate variability (HRV) research. The mean heart rate was more reproducible and could be more accu- rately estimated from very short segments be estimated accurately from short segments (Heart rate variability (HRV) Æ Interbeat

  13. Heart Rate Lowering by Specific and Selective If Current Inhibition with Ivabradine: A New Therapeutic Perspective in Cardiovascular Disease

    Microsoft Academic Search

    Dario DiFrancesco; John A. Camm

    2004-01-01

    and the mortality benefit of some cardiovascular drugs seems to be related in part to their heart rate-lowering effects. Since it is difficult to separate the benefit of heart rate lowering from other actions with currently available drugs, a 'pure' heart rate-lowering drug would be of great interest in establishing the benefit of heart rate reduction per se. Heart rate

  14. 12/01/2011 Article 1 1/23 Influence of blood glucose on heart rate and cardiac autonomic function.

    E-print Network

    Paris-Sud XI, Université de

    12/01/2011 Article 1 1/23 Influence of blood glucose on heart rate and cardiac autonomic function population, the effect of dysglycaemia, insulin resistance and metabolic parameters, on heart rate (HR), HR of HRV. Keywords: diabetes, epidemiology, heart rate, heart rate variability, heart rate recovery inserm

  15. Patient classification based on pre-hospital heart rate variability

    Microsoft Academic Search

    Pavitra Padmanabhan; Zhiping Lin; Guang-Bin Huang; M. E. H. Ong

    2008-01-01

    Heart rate variability (HRV) is a non-invasive measurement that has shown promise as an indicator of cardiovascular, respiratory and metabolic dynamics. In this study, three different classification techniques, i.e. extreme learning machine (ELM), support vector machine (SVM) and back-propagation based neural network (BP), were investigated to classify HRV signals obtained from electrocardiograms (ECGs) of critically ill patients seen at the

  16. SINGLE DOSE OF TIOTROPIUM DOES NOT EFFECT HEART RATE VARIABILITY

    Microsoft Academic Search

    Mehmet Unlu; Mehmet Melek; Fatma Fidan; Celal Kilit; Levent Tetik; Dayimi Kaya

    2006-01-01

    Aim: Anticholinergic drugs may alter cardiac autonomic modulation. The aim of this study was to investigate the effects of inhaled tiotropium on heart rate variability (HRV). Methods: A randomized, double-blind, crossover design study was conducted on 11 healthy volunteers. Tiotropium or placebo was administered in two different testing sessions. Time domain parameters; mean R-R interval (mean-RR), the standard deviation of

  17. Heart rate variability of children with mitral valve prolapse

    Microsoft Academic Search

    Lin Han; Ting Fei Ho; William CL Yip; Kit Yee Chan

    2000-01-01

    Studies have indicated that adult patients with mitral valve prolapse (MVP) may have autonomic dysfunction. The purpose of this study was to evaluate heart rate variability (HRV) in children with MVP. Sixty-seven children with MVP (ages 6 to 18 years; 30 boys and 37 girls) were consecutively studied and subdivided into those with or without symptoms. Thirty-seven normal age-matched children

  18. Estimating mental fatigue based on electroencephalogram and heart rate variability

    NASA Astrophysics Data System (ADS)

    Zhang, Chong; Yu, Xiaolin

    2010-01-01

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

  19. Heart rate variability (HRV): an indicator of stress

    NASA Astrophysics Data System (ADS)

    Kaur, Balvinder; Durek, Joseph J.; O'Kane, Barbara L.; Tran, Nhien; Moses, Sophia; Luthra, Megha; Ikonomidou, Vasiliki N.

    2014-05-01

    Heart rate variability (HRV) can be an important indicator of several conditions that affect the autonomic nervous system, including traumatic brain injury, post-traumatic stress disorder and peripheral neuropathy [3], [4], [10] & [11]. Recent work has shown that some of the HRV features can potentially be used for distinguishing a subject's normal mental state from a stressed one [4], [13] & [14]. In all of these past works, although processing is done in both frequency and time domains, few classification algorithms have been explored for classifying normal from stressed RRintervals. In this paper we used 30 s intervals from the Electrocardiogram (ECG) time series collected during normal and stressed conditions, produced by means of a modified version of the Trier social stress test, to compute HRV-driven features and subsequently applied a set of classification algorithms to distinguish stressed from normal conditions. To classify RR-intervals, we explored classification algorithms that are commonly used for medical applications, namely 1) logistic regression (LR) [16] and 2) linear discriminant analysis (LDA) [6]. Classification performance for various levels of stress over the entire test was quantified using precision, accuracy, sensitivity and specificity measures. Results from both classifiers were then compared to find an optimal classifier and HRV features for stress detection. This work, performed under an IRB-approved protocol, not only provides a method for developing models and classifiers based on human data, but also provides a foundation for a stress indicator tool based on HRV. Further, these classification tools will not only benefit many civilian applications for detecting stress, but also security and military applications for screening such as: border patrol, stress detection for deception [3],[17], and wounded-warrior triage [12].

  20. Autonomic contribution to heart rate recovery from exercise in humans.

    PubMed

    Savin, W M; Davidson, D M; Haskell, W L

    1982-12-01

    To assess the contribution of the autonomic nervous system to heart rate recovery following exertion, heart rate was observed after peak treadmill exercise in six men following parasympathetic blockade (PB) with atropine sulfate (0.03 mg/kg), sympathetic blockade (SB) with propranolol hydrochloride (0.20 mg/kg), double blockade (DB) with both drugs, and no drugs (ND). Least-squares analysis of each subject's heart rate (HR) as an exponential function of recovery time (t) was computed for each treatment giving an equation of the form HR = aebt. HRs at rest, peak exercise, and 10 min of recovery, the coefficients a and b, and the least-squares correlation coefficient (r) were compared among treatments by nonparametric analysis of variance and rank-sum multiple comparisons. HR recovered in an exponential manner after dynamic exercise in each subject with each of the treatment modes (P less than 0.01 for each r, mean across all treatments r = 0.94). Coefficients a and b differed the most between PB and SB. At the cessation of exercise the decreases in venous return and the systemic need for cardiac output are accompanied by an exponential HR decline. The exponential character of the cardiodeceleration seen after peak exercise appears to be an intrinsic property of the circulation because it occurred under each experimental condition. PMID:7153152

  1. Changes in nonlinear characteristics of heart rate variability under functional load on the cardiovascular system in healthy subjects and coronary heart disease patients

    Microsoft Academic Search

    A. Eidukaitis; G. Varoneckas; D. Žemaityté

    2006-01-01

    Some nonlinear characteristics of heart rate 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

  2. Subtle Physical Activity Poses a Challenge to the Study of Heart Rate

    Microsoft Academic Search

    Peter Major

    1998-01-01

    MAJOR, P.Subtle physical activity poses a challenge to the study of heart rate.PHYSIOL BEHAV 63(3) 381–384, 1998.—In nonhuman primates, our understanding of the effect of physical activity upon heart rate, particularly activity involving only slight, nonlocomotor movements, is poor. However, before inferring that other factors affect an animal’s heart rate, the effect of physical activity upon heart rate must be

  3. Time-variant modelling of heart rate responses to exercise intensity during road cycling

    Microsoft Academic Search

    Joris Lefever; Daniel Berckmans; Jean-Marie Aerts

    2012-01-01

    The aim of this study was to determine if heart rate responses to training intensity during road cycling could be modelled with compact time-variant mathematical model structures. The model performance was evaluated in terms of model order (complexity), number of inputs and parameter estimation methods used (time-invariant vs. time-variant). Thirteen male cyclists performed two identical cycling tests of 27 km

  4. A study of heart rate and heart rate variability in human subjects exposed to occupational levels of 50 Hz circularly polarised magnetic fields

    Microsoft Academic Search

    Mardi L. Sait; Andrew W. Wood; Hassan A. Sadafi

    1999-01-01

    The effects of power-frequency magnetic fields on heart rate and heart rate variability (HRV) were studied in groups of adult volunteers. Exposure consisted of 28 ?T (280 mG) at 50 Hz (circularly polarized) for 100 or 150 seconds either following or prior to a similar period of sham-exposure. A small but significant slowing of heart rate of the order of

  5. Identification of heart rate–associated loci and their effects on cardiac conduction and rhythm disorders

    PubMed Central

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

    2013-01-01

    Elevated resting heart rate is associated with greater risk of cardiovascular disease and mortality. In a 2-stage meta-analysis of genome-wide association studies in up to 181,171 individuals, we identified 14 new loci associated with heart rate and confirmed associations with all 7 previously established loci. Experimental downregulation of gene expression in Drosophila melanogaster and Danio rerio identified 20 genes at 11 loci that are relevant for heart rate regulation and highlight a role for genes involved in signal transmission, embryonic cardiac development and the pathophysiology of dilated cardiomyopathy, congenital heart failure and/or sudden cardiac death. In addition, genetic susceptibility to increased heart rate is associated with altered cardiac conduction and reduced risk of sick sinus syndrome, and both heart rate–increasing and heart rate–decreasing variants associate with risk of atrial fibrillation. Our findings provide fresh insights into the mechanisms regulating heart rate and identify new therapeutic targets. PMID:23583979

  6. The Heart Rate of Blind and Sighted Pedestrians on a Town Route

    Microsoft Academic Search

    R. J. WYCHERLEY; B. H. NICKLIN

    1970-01-01

    The heart rate of six matched pairs of blind and sighted subjects was telemetered as they walked over an unfamiliar town route on five consecutive occasions. Their resting heart rate was recorded for 2 min prior to each walk and for 5 min after. In addition the average heart rate for five 24-hour periods was obtained for each subject. The

  7. Within-subject electrocardiographic differences at equal heart rates: role of the autonomic nervous system

    Microsoft Academic Search

    Joost Frederiks; Cees A. Swenne; Jan A. Kors; Gerard van Herpen; Arie C. Maan; Jeroen V. Levert; Martin J. Schalij; Albert V. G. Bruschke

    2001-01-01

    Various combinations of sympathetic and vagal tone can yield the same heart rate, while ventricular electrophysiology differs. To demonstrate this in humans, we studied healthy volunteers in the sitting position with horizontal legs. First, heart rate was increased by lowering the legs to 60° and back. Thereafter, heart rate was increased by handgrip. In each subject, a leg-lowering angle was

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

    ERIC Educational Resources Information Center

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

    2010-01-01

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

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

    ERIC Educational Resources Information Center

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

    2008-01-01

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

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

    ERIC Educational Resources Information Center

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

    2008-01-01

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

  11. 1996 International Conference on Parallel Processing Analysis of Heart Rate Variability on a Massively Parallel

    E-print Network

    Bhandarkar, Suchendra "Suchi" M.

    1996 International Conference on Parallel Processing Analysis of Heart Rate Variability. The algorithm is used to compute the Kz entropy and correlation di- mension of experimental heart rate data (an be used as a measure of the heart rate variability and the level of chaos present in

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

    Microsoft Academic Search

    Mark Eijgelsheim; Christopher Newton-Cheh; Nona Sotoodehnia; Bakker de P. I. W; M. Müller; Alanna C. Morrison; Albert V. Smith; Aaron Isaacs; Serena Sanna; M. Dörr; P. Navarro; C. Fuchsberger; I. M. Nolte; Geus de E. J. C; K. Estrada; S.-J. Hwang; J. C. Bis; I.-M. Ruckert; A. Alonso; L. J. Launer; J. J. Hottenga; F. Rivadeneira Ramirez; P. A. Noseworthy; T. A. Rice; S. Perz; D. E. Arking; T. D. Spector; J. A. Kors; Y. S. Aulchenko; K. V. Tarasov; G. Homuth; S. H. Wild; F. Marroni; C. Gieger; C. M. M. Licht; R. J. Prineas; A. Hofman; J. I. Rotter; A. A. Hicks; F. D. J. Ernst; S. S. Najjar; A. F. Wright; A. Peters; E. R. Fox; B. A. Oostra; H. K. Kroemer; D. J. Couper; H. Völzke; H. Campbell; T. Meitinger; M. Uda; J. C. M. Witteman; B. M. Psaty; H.-E. Wichmann; T. B. Harris; S. Kääb; D. S. Siscovick; Y. Jamshidi; A. G. Uitterlinden; A. R. Folsom; M. G. Larson; J. F. Wilson; B. W. J. H. Penninx; H. Snieder; P. P. Pramstaller; P. Tikka-Kleemola; E. G. Lakatta; S. B. Felix; V. Gudnason; A. Pfeufer; S. R. Heckbert; B. H. Ch. Stricker; E. Boerwinkle; C. J. O'Donnell

    2010-01-01

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

  13. Effects of parasympathetic blockade on nonlinear dynamics of heart rate in mice

    E-print Network

    Clairambault, Jean

    Effects of parasympathetic blockade on nonlinear dynamics of heart rate in mice Jean Clairambault, Pascale Mansier, Bernard Swynghedauw Abstract-- The complexity of the heart rate series has been assessed. The resulting parasympathetic blockade produced an increase in the com- plexity of the heart rate (RR) series

  14. Nonlinear Heart Rate Variability in a Healthy Population: Influence of Age

    E-print Network

    Nonlinear Heart Rate Variability in a Healthy Population: Influence of Age S Vandeput1 , B Universiteit Leuven, Belgium Abstract Heart rate variability (HRV) measurements are used as markers of autonomic modulation of heart rate. Numerical noise titration was applied to a large healthy population

  15. hal00176298, A new stochastic process to model Heart Rate series

    E-print Network

    Paris-Sud XI, Université de

    hal­00176298, version 2 ­ 26 Mar 2008 A new stochastic process to model Heart Rate series during; Hurst parameter; Long­range dependence processes; Heart rate time series 1. Introduction The content. heart rate (HR) data during the race. The following #28;gure provides several examples of such data

  16. Sensitivity of detrended fluctuation analysis applied to heart rate variability of preterm newborns

    E-print Network

    Sensitivity of detrended fluctuation analysis applied to heart rate variability of preterm newborns.vanhuffel@esat.kuleuven.ac.be Abstract­Detrended fluctuation analysis (DFA), a fractal analysis method which is widely used in heart rate. It is shown that the scaling behaviour is not constant over such long segments and how heart rate patterns

  17. Cardiovascular control after spaceflight 1 Adaptation of the autonomic heart rate regulation in

    E-print Network

    Cardiovascular control after spaceflight 1 Adaptation of the autonomic heart rate regulation postflight recovery of linear and nonlinear neural markers of heart rate modulation, with a special focus from linear and nonlinear heart rate variability (HRV) parameters, separately during 2h day and 2h

  18. Heart rate dynamics during three forms of meditation C.-K. Penga,*, Isaac C. Henrya

    E-print Network

    Heart rate 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 heart rate dynamics patterns. Background: We analyzed beat-to-beat heart rate and continuous breathing signals from 10

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

    ERIC Educational Resources Information Center

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

    2002-01-01

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

  20. Effects of lying or standing on mammary blood flow and heart rate of dairy cows

    E-print Network

    Paris-Sud XI, Université de

    Effects of lying or standing on mammary blood flow and heart rate of dairy cows H Rulquin, JP of standing or lying on the mammary blood flow and heart rate in dairy cows. To widen the range of blood flow on the left common ex- ternal pudic artery by a transit-time blood flowmeter. Heart rate was determined

  1. Moving with the beat: heart rate and visceral temperature of free-swimming and feeding

    E-print Network

    Schluter, Dolph

    Moving with the beat: heart rate and visceral temperature of free-swimming and feeding bluefin tuna (Thunnus maccoyii ) to measure changes in the heart rate ( fH) and visceral temperature (TV) during a two, greater relative heart masses, elevated metabolic rates, and are more difficult to handle than tropical

  2. Large deviations estimates for the multiscale analysis of heart rate variability$,$$

    E-print Network

    Boyer, Edmond

    Large deviations estimates for the multiscale analysis of heart rate variability$,$$ Patrick to characterize relevant physiological factors impacting the heart rate variability. Notwithstanding. In this article, we illustrate the relevance of this approach, on both theoretical objects and on human heart rate

  3. An Enhanced Signal Processing Strategy For Fetal Heart Rate Detection Charles Brewton

    E-print Network

    Zahorian, Stephen A.

    ABSTRACT An Enhanced Signal Processing Strategy For Fetal Heart Rate Detection Charles Brewton Old the signal processing strategy for an acoustic fetal heart rate monitor. The theory, implementation, and testing of several possible signal processing strategies for fetal heart rate detection are presented

  4. J Clin Psychiatry . Author manuscript Combined effects of depressive symptoms and resting heart rate on

    E-print Network

    Paris-Sud XI, Université de

    and resting heart rate on mortality: the Whitehall II prospective cohort study Hermann Nabi 1 2 * , Mika Kivim symptoms and resting heart rate (RHR) on mortality. Methods Data come from 5936 participants, aged 61 6 improve survival. Author Keywords depression ; resting heart rate and mortality INTRODUCTION Depression

  5. Analysis of Physiological Meaning of Detrended Fluctuation Analysis in Heart Rate

    E-print Network

    Sánchez, Angel "Anxo"

    Analysis of Physiological Meaning of Detrended Fluctuation Analysis in Heart Rate Variability Using Fluctuation Analysis (DFA), have been widely used for quantifying the Heart Rate Variability (HRV) for cardiac lumped parameter models. 1. Introduction During the last years, Heart Rate Variability (HRV) sig- nal has

  6. Multifractal Analysis of Fetal Heart Rate Variability in Fetuses with and without Severe

    E-print Network

    Abry, Patrice

    Multifractal Analysis of Fetal Heart Rate Variability in Fetuses with and without Severe Acidosis multifractal analysis of fetal heart rate (FHR) variability in fetuses with and without acidosis during labor and nonacidotic fetuses, independently from FHR pattern. KEYWORDS: Acidosis, fetal heart rate, labor, multifractal

  7. ORAL PRESENTATION ABSTRACT Design of Heart Rate and Blood Oxygen Saturation Monitoring Device

    E-print Network

    Haykin, Simon

    ORAL PRESENTATION ABSTRACT Design of Heart Rate and Blood Oxygen Saturation Monitoring Device to a processing centre wirelessly, where it can be monitored and forwarded to necessary personnel. Heart rate signal. This technique is called Photoplethysmography (PPG), and can be used to calculate the heart rate

  8. Methodology for Multifractal Analysis of Heart Rate Variability: From LF/HF Ratio to Wavelet Leaders

    E-print Network

    Gonçalves, Paulo

    Methodology for Multifractal Analysis of Heart Rate Variability: From LF/HF Ratio to Wavelet introduction to the practical use of wavelet Leader based multifractal analysis to study heart rate variability to other standard characterizations of heart rate variability: (mono)fractal analysis, Hurst exponent

  9. Spectral and symbolic analysis of Heart Rate data during Tilt Test

    E-print Network

    Cammarota, Camillo

    Spectral and symbolic analysis of Heart Rate data during Tilt Test Camillo Cammarota Enrico Rogora Abstract Spectral analysis of heart rate sequences is commonly used to inves- tigate neuroauthonomic control of heart rate by means of two indexes, the low and the high frequency power. For tilt test data

  10. Characterizing heart rate variability by scale-dependent Lyapunov exponent Jing Hu,1,2

    E-print Network

    Gao, Jianbo

    Characterizing heart rate 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 heart rate variability HRV using, since heart rate variability (HRV) may exhibit both nonlinear, and possibly chaotic, as well

  11. Accurate R Peak Detection and Advanced Preprocessing of Normal ECG for Heart Rate Variability Analysis

    E-print Network

    Accurate R Peak Detection and Advanced Preprocessing of Normal ECG for Heart Rate Variability, The Netherlands Abstract Heart rate variability (HRV) analysis is well-known to give information about the autonomic heart rate modula- tion mechanism. In order to avoid erroneous conclusions, it is of great

  12. Physica A 249 (1998) 587593 Scaling and universality in heart rate

    E-print Network

    Potsdam, Universität

    1998-01-01

    Physica A 249 (1998) 587­593 Scaling and universality in heart rate variability distributions P.V. All rights reserved. Time series of beat-to-beat (RR) heart rate intervals obtained from digitized erent (e.g. smaller) during illness, the pattern of heart rate variability might be otherwise very

  13. Large deviations estimates for the multiscale analysis of heart rate variability$,$$

    E-print Network

    Gonçalves, Paulo

    Large deviations estimates for the multiscale analysis of heart rate variability$,$$ Patrick physiological factors impacting the heart rate variability. Notwithstanding these considerable progresses, multi the relevance of this approach, on both theoretical objects and on human heart rate signals from the Physionet

  14. DIFFERENT PATTERNS OF AUTONOMIC HEART RATE CONTROL DURING HYPOXIA IN FETAL AND NEWBORN LAMBS

    E-print Network

    Paris-Sud XI, Université de

    DIFFERENT PATTERNS OF AUTONOMIC HEART RATE CONTROL DURING HYPOXIA IN FETAL AND NEWBORN LAMBS A of heart rate (HR) during hypoxia was studied longitudinally in nine unanaesthetised fetal lambs (109 days recovery. Changes in heart rate (! HR) during hypoxia were age-dependent; before 120 days gestation 0 HR

  15. Wrapper subset evaluation facilitates the automated detection of diabetes from heart rate variability measures

    E-print Network

    Teich, Malvin C.

    Wrapper subset evaluation facilitates the automated detection of diabetes from heart rate heart rate variability measures. These data are well suited to the diagnosis of cardiac dysfunction that the detection of diabetes is feasible from heart rate variability measures. D. J. Cornforth, H. F. Jelinek, M. C

  16. A combined heart rate and movement sensor: proof of concept and preliminary testing study

    Microsoft Academic Search

    K Rennie; T Rowsell; SA Jebb; D Holburn; NJ Wareham; NJ Wareham

    2000-01-01

    Objective: Heart rate monitoring has previously been used as a technique for measuring energy expenditure (EE) in field studies. However, the combination of heart rate monitoring with movement sensoring could have theoretical advantages compared to either method used alone. Therefore, this study was undertaken to develop and validate a new combined heart rate monitor and movement sensor instrument (HR+M) for

  17. Possible forms of heart-rate variability and their application: use of heart-rate variability in assessment of surgical patients

    Microsoft Academic Search

    T.-Y. Slonim; M. Slonim; G. Daychman; L. Roytblat; I. Ovsyshcher

    1997-01-01

    A new approach has been proposed for the estimation of variables based on Heart Rate Variability during a surgical operation. The following variables, Heart Rate Variability Index, Normalized Inert Rate Variability Index and Integral Estimation have been introduced and used for the analysis and estimation of surgical procedures in 7 patients. All variables have a clear physical meaning; they are

  18. G E N E R A L A R T I C L E Heart Rate Sonification: A New

    E-print Network

    Glass, Leon

    G E N E R A L A R T I C L E Heart Rate Sonification: A New Approach to Medical Diagnosis Mark sounds, we explore whether phys- iological variations in heart rate dynamics over a period of hours could- tion taken from an auditory display of human heart rate vari- ability? HEART RATE VARIABILITY Heart

  19. Combined use of autogenic therapy and biofeedback in training effective control of heart rate by humans

    NASA Technical Reports Server (NTRS)

    Cowings, P. S.

    1977-01-01

    Experiments were performed on 24 men and women (aged 20-27 yr) in three equal groups who were taught to control their own heart rates 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 heart rates. 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.

  20. Electrocardiogram, heart movement and heart rate in the awake gecko (Hemidactylus mabouia).

    PubMed

    Germer, Carina M; Tomaz, Juliana M; Carvalho, Ana F; Bassani, Rosana A; Bassani, José W M

    2015-01-01

    The electrocardiogram (ECG) is the simplest and most effective non-invasive method to assess the electrical activity of the heart and to obtain information on the heart rate (HR) and rhythm. Because information on the HR of very small reptiles (body mass <10 g) is still scarce in the literature, in the present work we describe a procedure for recording the ECG in non-anesthetized geckos (Hemidactylus mabouia, Moreau de Jonnès, 1818) under different conditions, namely manual restraint (MR), spontaneous tonic immobility (TI), and in the non-restrained condition (NR). In the gecko ECG, the P, QRS and T waves were clearly distinguishable. The HR was 2.83 ± 0.02 Hz under MR, which was significantly greater (p < 0.001) than the HR under the TI (1.65 ± 0.09 Hz) and NR (1.60 ± 0.10 Hz) conditions. Spontaneously beating isolated gecko hearts contracted at 0.84 ± 0.03 Hz. The in vitro beating rate was affected in a concentration-dependent fashion by adrenoceptor stimulation with noradrenaline, as well as by the muscarinic cholinergic agonist carbachol, which produced significant positive and negative chronotropic effects, respectively (p < 0.001). To our knowledge, this is the first report on the ECG morphology and HR values in geckos, particularly under TI. The methodology and instrumentation developed here are useful for non-invasive in vivo physiological and pharmacological studies in small reptiles without the need of physical restraint or anesthesia. PMID:25395252

  1. Modeling heart rate regulation--part II: parameter identification and analysis.

    PubMed

    Fowler, K R; Gray, G A; Olufsen, M S

    2008-06-01

    In part I of this study we introduced a 17-parameter model that can predict heart rate regulation during postural change from sitting to standing. In this subsequent study, we focus on the 17 model parameters needed to adequately represent the observed heart rate response. In part I and in previous work (Olufsen et al. 2006), we estimated the 17 model parameters by minimizing the least squares error between computed and measured values of the heart rate using the Nelder-Mead method (a simplex algorithm). In this study, we compare the Nelder-Mead optimization method to two sampling methods: the implicit filtering method and a genetic algorithm. We show that these off-the-shelf optimization methods can work in conjunction with the heart rate model and provide reasonable parameter estimates with little algorithm tuning. In addition, we make use of the thousands of points sampled by the optimizers in the course of the minimization to perform an overall analysis of the model itself. Our findings show that the resulting least-squares problem has multiple local minima and that the non-linear-least squares error can vary over two orders of magnitude due to the complex interaction between the model parameters, even when provided with reasonable bound constraints. PMID:18172764

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

    PubMed

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

    2015-03-01

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

  3. Heart rates increase after hatching in two species of natricine snakes

    PubMed Central

    Aubret, Fabien

    2013-01-01

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

  4. Effects of whole body heating on dynamic baroreflex regulation of heart rate in humans

    Microsoft Academic Search

    C. G. CRANDALL; R. ZHANG; B. D. LEVINE

    Crandall, C. G., R. Zhang, and B. D. Levine. Effects of whole body heating on dynamic baroreflex regulation of heart rate 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 heart rate (HR) is altered during whole body heating. In 14 subjects, dynamic baroreflex regulation of

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

    PubMed Central

    2014-01-01

    Background This study is aimed to evaluate the clinical significance of heart rate turbulence (HRT) parameters in predicting the prognosis in patients with chronic heart failure (CHF). Methods From June 2011 to December 2012, a total of 104 CHF patients and 30 healthy controls were enrolled in this study. We obtained a 24-hour Holter ECG recording to assess the HRT parameters, included turbulence onset (TO), turbulence slope (TS), standard deviation of N-N intervals (SDNN), and resting heart rate (RHR). The relationships between HRT parameters and the prognosis of CHF patients were determined. Results The assessment follow-up period lasted until January 31, 2013. The overall mortality of CHF patients was 9.6% (10/104). Our results revealed that CHF patients had higher levels of TO than those of healthy subjects, but the TS levels of CHF patients were lower than that of the control group. CHF patients with NYHA grade IV had higher HRT1/2 rate than those with NYHA grade II/III. There were statistical differences in TS, LVEF, SDNN and RHR between the non-deteriorating group and the non-survivor group. Significant differences in TS among the three groups were also found. Furthermore, CHF patients in the non-survivor group had lower levels of TS than those in the deteriorating group. Correlation analyses indicated that TO negatively correlate with SDNN, while TS positively correlated with SDNN and left ventricular ejection fraction (LVEF). We also observed negative correlations between TS and left ventricular end-diastolic cavity dimension (LVEDD), RHR, homocysteine (Hcy) and C-reactive protein (CRP). Multivariate Cox regression analysis further confirmed that LVEF (?30%), HRT2, SDNN and RHR were independent risk factors which can indicate poor prognosis in CHF patients. Conclusions Our findings indicate that HRT may have good clinical predictive value in patients with CHF. Thus, quantifying HRT parameters could be a useful tool for predicting mortality in CHF patients. PMID:24725657

  6. TEMPERATURE AND HEART RATE IN PTEROTRACHEA AND TIEDEMANNIA.

    PubMed

    Glaser, O

    1925-11-20

    1. For the heart rate 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 heart rate 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

  7. TEMPERATURE AND HEART RATE IN PTEROTRACHEA AND TIEDEMANNIA

    PubMed Central

    Glaser, Otto

    1925-01-01

    1. For the heart rate 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 heart rate 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

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

    PubMed

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

    2015-01-01

    Environmental factors in space are dramatically different from those on Earth. The spaceflight environment has been known to influence human physiology and behavior on orbital missions. In this study, we investigated alterations in the diurnal rhythms of activity and heart rate of three Chinese astronauts on a space mission. An analysis of the heart rate data showed a significant decrease in heart rate amplitudes during flight in all three subjects. The heart rate amplitudes of all the three astronauts were significantly dampened during flight, and the minimum as well as the maximum value of heart rate increased after flight. A phase shift in heart rate was observed in one of the three astronauts after flight. These results demonstrate the influence of spaceflight on heart physiology and function. In addition, a significant decrease in body trunk activity and rhythmicity occurred during flight, demonstrating that the spaceflight environment disturbs motion adaptation and diurnal activity rhythms. PMID:26177621

  9. Exercise heart rates in patients with hypertrophic cardiomyopathy.

    PubMed

    Luo, Hong-Chang; Dimaano, Veronica L; Kembro, Jackelyn M; Hilser, Alex; Hurtado-de-Mendoza, David; Pozios, Iraklis; Tomas, Miguel S; Yalcin, Hulya; Dolores-Cerna, Ketty; Mormontoy, Wilfredo; Aon, Miguel A; Cameron, Duke; Bluemke, David A; Stewart, Kerry J; Russell, Stuart D; Cordova, Jorge G; Abraham, Theodore P; Abraham, M Roselle

    2015-04-15

    The exercise heart rate (HR) profile and its relation to cardiac function and arrhythmias were investigated in patients with hypertrophic cardiomyopathy (HC). Chronotropic response (CR) and heart rate recovery (HRR) were computed during and after treadmill exercise testing in 273 patients with HC and 95 age-matched healthy controls. Patients with HC had higher prevalence of chronotropic incompetence and lower HRR1-5min compared with controls. Exercise capacity, diastolic function (assessed by E/e') and left atrial volume index were associated with HRR1min and CR in HC. Septal myectomy was associated with reduction in chronotropic incompetence but did not affect HRR1min. In conclusion, impaired CR and HRR1min are associated with advanced disease and do not appear to be independent clinical markers indicating high-risk status in HC. Improving CR by titrating doses of negative chronotropic agents, myectomy, and atrial pacing may be useful to increase exercise capacity in patients with HC. PMID:25746289

  10. Fetal behavior and heart rate in twin pregnancy: a review.

    PubMed

    Tendais, Iva; Visser, Gerard H A; Figueiredo, Bárbara; Montenegro, Nuno; Mulder, Eduard J H

    2013-04-01

    Fetal movements and fetal heart rate (FHR) are well-established markers of fetal well-being and maturation of the fetal central nervous system. The purpose of this paper is to review and discuss the available knowledge on fetal movements and heart rate patterns in twin pregnancies. There is some evidence for an association or similarity in fetal movement incidences or FHR patterns between both members of twin pairs. However, the temporal occurrence of these patterns seems to be for the most part asynchronous, especially when stricter criteria are used to define synchrony. The available data suggest that fetal behavior is largely independent of sex combination, fetal position, and presentation. Conversely, chorionicity appears to have some influence on fetal behavior, mainly before 30 weeks of gestation. There is preliminary evidence for the continuity of inter-individual differences in fetal activity and FHR patterns over pregnancy. Comparisons between studies are limited by large methodological differences and absence of uniform concepts and definitions. Future studies with high methodological quality are needed to provide a more comprehensive knowledge of normal fetal behavior in twin pregnancy. PMID:23312077

  11. [Study of exercise heart rate variability based on correlation dimension].

    PubMed

    Li, Xia; Kang, Tianliang; Quan, Haiying; Liu, Jinghua; Xu, Jin; Tian, Xin

    2009-10-01

    This paper is mainly devoted to the relationship between the correlation dimension (CD) of exercise heart rate variability (EHRV) and the status of cardiovascular function. Hypertensive patients and healthy people were enrolled in two contrast groups. Dynamic electrocardiograph (ECG) in step exercise was recorded. EHRV was extracted by wavelet transform. The CDs in the whole course of exercise and in three stages of exercise were calculated, the three stages being named rest-before-exercise, during-exercise, and after-exercise. SPSS software was used for statistical analysis. The results revealed all the CDs showed significant difference between two groups except that in the stage of during exercise. By discrimination analysis, the average correct rate was 92.2%. It indicated that the CD in stress status probably could be an effective non-linear parameter for assessing cardiovascular function status. PMID:19947468

  12. Scientific Comparison of Different Online Heart Rate Monitoring Systems

    PubMed Central

    Schönfelder, Martin; Hinterseher, Georg; Peter, Philipp; Spitzenpfeil, Peter

    2011-01-01

    Recent technical development focused on real-time heart rate monitoring instead of postexercise evaluation of recorded data. There are several systems on the market that allow direct and real-time monitoring of several individuals at the same time. The present study compared the systems of Polar, Acentas, Activio, and Suunto in a field test with twelve subjects regarding failure quota, operating distance, and ECG validity. Moreover, the installation and use of software and hardware were evaluated with a quality rating system. Chest belts were evaluated with a questionnaire, too. Overall the system of Acentas reached the best mark of all systems, but detailed results showed that every system has its advantages and disadvantages depending on using purpose, location, and weather. So this evaluation cannot recommend a single system but rather shows strength and weakness of all systems and additionally can be used for further system improvements. PMID:21760780

  13. Scientific comparison of different online heart rate monitoring systems.

    PubMed

    Schönfelder, Martin; Hinterseher, Georg; Peter, Philipp; Spitzenpfeil, Peter

    2011-01-01

    Recent technical development focused on real-time heart rate monitoring instead of postexercise evaluation of recorded data. There are several systems on the market that allow direct and real-time monitoring of several individuals at the same time. The present study compared the systems of Polar, Acentas, Activio, and Suunto in a field test with twelve subjects regarding failure quota, operating distance, and ECG validity. Moreover, the installation and use of software and hardware were evaluated with a quality rating system. Chest belts were evaluated with a questionnaire, too. Overall the system of Acentas reached the best mark of all systems, but detailed results showed that every system has its advantages and disadvantages depending on using purpose, location, and weather. So this evaluation cannot recommend a single system but rather shows strength and weakness of all systems and additionally can be used for further system improvements. PMID:21760780

  14. Heart Rate Variability in Sleep-Related Migraine without Aura

    PubMed Central

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

    2013-01-01

    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 heart rate 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. Heart rate variability in sleep-related migraine without aura. J Clin Sleep Med 2013;9(7):707-714. PMID:23853566

  15. Effects of prenatal visual stimulation on growth and heart rate in bobwhite quail (Colinus virginianus).

    PubMed

    Sleigh, Merry J; Birchard, Geoffrey

    2006-05-01

    This study examined the effects of prenatal visual stimulation on bobwhite quail embryos' growth and heart rate. 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 heart rates in response to visual stimulation than did naïve embryos. In a subsequent experiment, naïve embryos that underwent an egg-opening procedure exhibited heart rates that were lower than embryos measured in intact eggshells. Embryos in opened eggs maintained lower heart rates than comparison embryos across time; however, a less invasive egg-opening procedure led to a quicker heart rate recovery than did a more invasive egg-opening procedure. These findings indicate that prenatal heart rate responses may be mediated by multiple features of the organism's developmental context, including intensity and duration of sensory stimulation. PMID:16617467

  16. Behavioral correlates of heart rates of free-living Greater White-fronted Geese

    USGS Publications Warehouse

    Ely, C.R.; Ward, D.H.; Bollinger, K.S.

    1999-01-01

    We simultaneously monitored the heart rate and behavior of nine free-living Greater White-fronted Geese (Anser albifrons) on their wintering grounds in northern California. Heart rates of wild geese were monitored via abdominally-implanted radio transmitters with electrodes that received electrical impulses of the heart and emitted a radio signal with each ventricular contraction. Post-operative birds appeared to behave normally, readily rejoining flocks and flying up to 15 km daily from night-time roost sites to feed in surrounding agricultural fields. Heart rates varied significantly among individuals and among behaviors, and ranged from less than 100 beats per minute (BPM) during resting, to over 400 BPM during flight. Heart rates varied from 80 to 140 BPM during non-strenuous activities such as walking, feeding, and maintenance activities, to about 180 BPM when birds became alert, and over 400 BPM when birds were startled, even if they did not take flight. Postflight heart rate recovery time averaged < 10 sec. During agonistic encounters, heart rate exceeded 400 BPM; heart rates during social interactions were not predictable solely from postures, as heart rates were context-dependent, and were highest in initial encounters among individuals. Instantaneous measures of physiological parameters, such as heart rate, are often better indicators of the degree of response to external stimuli than visual observations and can be used to improve estimates of energy expenditure based solely on activity data.

  17. Exercise Training Improves Heart Rate Variability after Methamphetamine Dependency

    PubMed Central

    Dolezal, Brett A.; Chudzynski, Joy; Dickerson, Daniel; Mooney, Larissa; Rawson, Richard A.; Garfinkel, Alan; Cooper, Christopher B.

    2014-01-01

    Purpose Heart rate variability (HRV) reflects a healthy autonomic nervous system and is increased with physical training. Methamphetamine dependence (MD) causes autonomic dysfunction and diminished HRV. We compared recently abstinent MD participants with age-matched, drug free controls (DF) and also investigated whether HRV can be improved with exercise training in the MD participants. Methods In 50 participants (MD=28; DF=22) resting heart rate (R-R intervals) was recorded over 5 min while seated using a monitor affixed to a chest strap. Previously reported time-domain (SDNN, RMSSD, pNN50) and frequency-domain (LFnu, HFnu, LF/HF) parameters of HRV were calculated with customized software. MD were randomized to thrice weekly exercise training (ME=14) or equal attention without training (MC=14) over 8 weeks. Groups were compared using paired and unpaired t-tests. Statistical significance was set at P?0.05. Results Participant characteristics were matched between groups: age 33±6 years; body mass 82.7±12 kg, BMI 26.8±4.1 kg•min?2, mean±SD. Compared with DF, the MD group had significantly higher resting heart rate (P<0.05), LFnu, and LF/HF (P<0.001) as well as lower SDNN, RMSSD, pNN50 and HFnu (all P<0.001). At randomization, HRV indices were similar between ME and MC groups. However, after training, the ME group significantly (all P<0.001) increased SDNN (+14.7±2.0 ms, +34%), RMSSD (+19.6±4.2 ms, +63%), pNN50 (+22.6±2.7%, +173%), HFnu (+14.2±1.9, +60%) and decreased HR (?5.2±1.1 beats·min?1, ?7%), LFnu (?9.6±1.5, ?16%) and LF/HF (?0.7±0.3, ?19%). These measures did not change from baseline in the MC group. Conclusion HRV, based on several conventional indices, was diminished in recently abstinent, methamphetamine dependent individuals. Moreover, physical training yielded a marked increase of HRV representing increased vagal modulation or improved autonomic balance. PMID:24162556

  18. Development of heart rate rhythmicity in Muscovy duck embryos.

    PubMed

    Höchel, J; Mohr, E; Nichelmann, M; Pirow, R; Tazawa, H

    1999-12-01

    The heart rate (HR) of Muscovy duck embryos (Cairina moschata f. domestica) was continuously recorded from as early as the 21st day of incubation (D21) until hatching (D34/35). The aim of the study was to investigate the influence of phonoperiods consisting of different acoustic stimuli on the course of HR and the development of HR periodicities during this period. Incubation was carried out at a constant temperature and in constant darkness. Until D25 HR was dominated by decelerative fluctuations only, indicating a main input from the parasympathetic system on the heart. Later sympathetic influences increased progressively. HR periodicity was investigated by means of chi 2-periodogram and fast Fourier transformation. Between D26 and D30 statistically significant and stable HR periodicities developed gradually. They had periods in the range from 5 to 38 h. Ultra-, circa- and infradian rhythms (< 20, 24 +/- 4 and > 28 h, respectively) occurred in parallel in some cases in the same embryo. The for the HR course important periods were dissimilar between individual embryos and had different intensities. There was no indication that acoustic stimulation (phonoperiods) had any effect on the development of HR periodicities. PMID:10682249

  19. The effect of locus of control and learned helplessness on control of heart rate using biofeedback 

    E-print Network

    Logsdon, Steven Alan

    1976-01-01

    RATE SITUATION USING CHANCE LOCUS OF CONTROL TRIAL 1 23 iX LIST OF FIGURES Page FIGURE 1. Graphic representation of pretaped bogus feedback of "electrorheographic" output designed to give the impression of either success or failure on the task.... FIGURE 2. A flow chart to help illustrate the pro- cedure used in the study 12 15 FIGURE 3. Change in heart rate from baseline in the heart rate decrease condition. FIGURE 4. Change in heart rate from baseline in Trial 1 in the heart rate increase...

  20. Heart Rate Response to a Timed Walk and Cardiovascular Outcomes in Older Adults: The Cardiovascular Health Study

    Microsoft Academic Search

    Saket Girotra; Dalane W. Kitzman; Willem J. Kop; Phyllis K. Stein; John S. Gottdiener; Kenneth J. Mukamal

    2012-01-01

    Objectives: To determine the relationship between heart rate response during low-grade physical exertion (6-min walk) with mortality and adverse cardiovascular outcomes in the elderly. Methods: Participants in the Cardiovascular Health Study who completed a 6-min walk test were included. We used delta heart rate (difference between postwalk heart rate and resting heart rate) as a measure of chronotropic response and

  1. Heart rate variability in idiopathic dilated cardiomyopathy: relation to disease severity and prognosis.

    PubMed Central

    Yi, G.; Goldman, J. H.; Keeling, P. J.; Reardon, M.; McKenna, W. J.; Malik, M.

    1997-01-01

    OBJECTIVE: To assess the clinical importance of heart rate variability (HRV) in patients with idiopathic dilated cardiomyopathy (DCM). PATIENTS AND METHODS: Time domain analysis of 24 hour HRV was performed in 64 patients with DCM, 19 of their relatives with left ventricular enlargement (possible early DCM), and 33 healthy control subjects. RESULTS: Measures of HRV were reduced in patients with DCM compared with controls (P < 0.05). HRV parameters were similar in relatives and controls. Measures of HRV were lower in DCM patients in whom progressive heart failure developed (n = 28) than in those who remained clinically stable (n = 36) during a follow up of 24 (20) months (P = 0.0001). Reduced HRV was associated with NYHA functional class, left ventricular end diastolic dimension, reduced left ventricular ejection fraction, and peak exercise oxygen consumption (P < 0.05) in all patients. DCM patients with standard deviation of normal to normal RR intervals calculated over the 24 hour period (SDNN) < 50 ms had a significantly lower survival rate free of progressive heart failure than those with SDNN > 50 ms (P = 0.0002, at 12 months; P = 0.0001, during overall follow up). Stepwise multiple regression analysis showed that SDNN < 50 ms identified, independently of other clinical variables, patients who were at increased risk of developing progressive heart failure (P = 0.0004). CONCLUSIONS: HRV is reduced in patients with DCM and related to disease severity. HRV is clinically useful as an early non-invasive marker of DCM deterioration. PMID:9068391

  2. A new algorithm for wavelet-based heart rate variability analysis

    E-print Network

    García, Constantino A; Vila, Xosé; Márquez, David G

    2014-01-01

    One of the most promising non-invasive markers of the activity of the autonomic nervous system is Heart Rate Variability (HRV). HRV analysis toolkits often provide spectral analysis techniques using the Fourier transform, which assumes that the heart rate series is stationary. To overcome this issue, the Short Time Fourier Transform is often used (STFT). However, the wavelet transform is thought to be a more suitable tool for analyzing non-stationary signals than the STFT. Given the lack of support for wavelet-based analysis in HRV toolkits, such analysis must be implemented by the researcher. This has made this technique underutilized. This paper presents a new algorithm to perform HRV power spectrum analysis based on the Maximal Overlap Discrete Wavelet Packet Transform (MODWPT). The algorithm calculates the power in any spectral band with a given tolerance for the band's boundaries. The MODWPT decomposition tree is pruned to avoid calculating unnecessary wavelet coefficients, thereby optimizing execution t...

  3. Restlessness behaviour, heart rate and heart-rate variability of dairy cows milked in two types of automatic milking systems and auto-tandem milking parlours

    Microsoft Academic Search

    Lorenz Gygax; Isabelle Neuffer; Christine Kaufmann; Rudolf Hauser; Beat Wechsler

    2008-01-01

    In order to assess the welfare of cows milked in automatic milking systems (AMS), restlessness behaviour during milking (stepping, foot-lifting), heart rate (HR) and heart-rate variability (HRV) were investigated in cows milked in two different AMS models (AMS-1, AMS-2) and in auto-tandem milking parlours (ATM) on four commercial farms in each case.Stepping rates and proportions of milkings with foot-lifting were

  4. A Heart Rate Analysis of Developmental Change in Feedback Processing and Rule Shifting from Childhood to Early Adulthood

    ERIC Educational Resources Information Center

    Crone, Eveline A.; Somsen, Riek J. M.; Zanolie, Kiki; Van der Molen, Maurits W.

    2006-01-01

    Over the course of development, the ability to switch between different tasks on the basis of feedback cues increases profoundly, but the role of performance monitoring remains unclear. Heart rate indexes can provide critical information about how individuals monitor feedback cues indicating that performance should be adjusted. In this study,…

  5. The autonomic nervous control of heart rate in ducks during voluntary diving.

    PubMed

    McPhail, L T; Jones, D R

    1999-01-01

    Autonomic nervous control of heart rate was studied in voluntarily diving ducks (Aythya affinis). Ducks were injected with the muscarinic blocker atropine, the beta-adrenergic blocker nadolol, the beta-adrenergic agonist isoproterenol, and a combination of both atropine and nadolol. Saline injection was used as a control treatment. The reduction in heart rate (from the predive level) normally seen during a dive was abolished by atropine. Nadolol reduced heart rate during all phases of diving activity-predive, dive, and postdive-indicating that sympathetic output to the heart was not withdrawn during diving. Isoproterenol increased heart rate before, during, and after the dive, although the proportional increase in heart rate was not as high during the dive as compared with the increase in routine heart rate or heart rate during the predive or postdive phase. The parasympathetic system predominates in the control of heart rate during diving despite the maintenance of efferent sympathetic influences to the heart, perhaps due to accentuated antagonism between the two branches of the autonomic nervous system. PMID:10068619

  6. Heart rate, startle response, and intrusive trauma memories.

    PubMed

    Chou, Chia-Ying; La Marca, Roberto; Steptoe, Andrew; Brewin, Chris R

    2014-03-01

    The current study adopted the trauma film paradigm to examine potential moderators affecting heart rate (HR) as an indicator of peritraumatic psychological states and as a predictor of intrusive memories. We replicated previous findings that perifilm HR decreases predicted the development of intrusive images and further showed this effect to be specific to images rather than thoughts, and to detail rather than gist recognition memory. Moreover, a group of individuals showing both an atypical sudden reduction in HR after a startle stimulus and higher trait dissociation was identified. Only among these individuals was lower perifilm HR found to indicate higher state dissociation, fear, and anxiety, along with reduced vividness of intrusions. The current findings emphasize how peritraumatic physiological responses relate to emotional reactions and intrusive memory. The moderating role of individual difference in stress defense style was highlighted. PMID:24397333

  7. Emergence of dynamical complexity related to human heart rate variability

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

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

  8. Heart rate arousal and excitement in gambling: winners versus losers.

    PubMed

    Wulfert, Edelgard; Roland, Brian D; Hartley, Julie; Wang, Naitian; Franco, Christine

    2005-09-01

    People sometimes claim they gamble for excitement rather than money. The authors examined in a laboratory analog whether excitement is generated by the expectancy of winning money. Eighty male undergraduate students watched a videotaped horse race with an exciting neck-to-neck finish. Half bet $1 for a chance of winning $7 if they picked the winning horse; the other half predicted the winning horse without wagering. Winning and losing were experimentally manipulated. Participants with a chance to win money showed greater heart rate (HR) elevations and reported more subjective excitement while watching the race compared with those who did not wager. Of students who wagered, the winners showed higher HRs after the end of the race than did those who lost, even though differences in subjective excitement were not statistically significant. The findings suggest that the expectancy of winning money is an important contributing factor to the excitement associated with gambling. PMID:16187811

  9. Correlated and uncorrelated heart rate fluctuations during relaxing visualization

    NASA Astrophysics Data System (ADS)

    Papasimakis, N.; Pallikari, F.

    2010-05-01

    The heart rate variability (HRV) of healthy subjects practicing relaxing visualization is studied by use of three multiscale analysis techniques: the detrended fluctuation analysis (DFA), the entropy in natural time (ENT) and the average wavelet (AWC) coefficient. The scaling exponent of normal interbeat interval increments exhibits characteristics of the presence of long-range correlations. During relaxing visualization the HRV dynamics change in the sense that two new features emerge independent of each other: a respiration-induced periodicity that often dominates the HRV at short scales (<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.

  10. Heart rate variability at different thermal comfort levels.

    PubMed

    Liu, Weiwei; Lian, Zhiwei; Liu, Yuanmou

    2008-06-01

    The mechanism of human thermal comfort is important for building a comfortable and healthy indoor environment. This paper analyzes human heart rate 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

  11. Design of an FECG scalp electrode fetal heart rate monitor.

    PubMed

    Reguig, F B; Kirk, D L

    1996-03-01

    The design of a fetal heart rate (FHR) monitor using fetal electrocardiogram (FECG) scalp electrodes is described. It is shown that the design approach followed two stages: generation of FHR pulses at R-R intervals and FHR computation. The former uses a simple hardware approach for QRS detection and R-wave enhancement, while the latter requires a software implementation in order to produce FHR traces on a beat to beat basis. The QRS detection is based on bandpass filtering using switched mode capacitor technique; the R-wave enhancement and amplitude information are achieved by differentiation followed by fullwave rectification and peak detection. An adaptive threshold together with a comparator circuit are used to generate FHR pulses at R-R intervals. Beat to beat variations of FHR traces are produced by hardware and software implementation on a Z80 microprocessor board. Results obtained by the FHR monitor are evaluated and contrasted to other commercial FHR monitors. PMID:8673321

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

    PubMed

    Sammito, S; Böckelmann, I

    2015-03-01

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

  13. Heart rate, startle response, and intrusive trauma memories

    PubMed Central

    Chou, Chia-Ying; Marca, Roberto La; Steptoe, Andrew; Brewin, Chris R

    2014-01-01

    The current study adopted the trauma film paradigm to examine potential moderators affecting heart rate (HR) as an indicator of peritraumatic psychological states and as a predictor of intrusive memories. We replicated previous findings that perifilm HR decreases predicted the development of intrusive images and further showed this effect to be specific to images rather than thoughts, and to detail rather than gist recognition memory. Moreover, a group of individuals showing both an atypical sudden reduction in HR after a startle stimulus and higher trait dissociation was identified. Only among these individuals was lower perifilm HR found to indicate higher state dissociation, fear, and anxiety, along with reduced vividness of intrusions. The current findings emphasize how peritraumatic physiological responses relate to emotional reactions and intrusive memory. The moderating role of individual difference in stress defense style was highlighted. PMID:24397333

  14. Effects of Moxa (Folium Artemisiae argyi) Smoke Exposure on Heart Rate and Heart Rate Variability in Healthy Young Adults: A Randomized, Controlled Human Study

    PubMed Central

    Cui, Yingxue; Zhao, Baixiao; Huang, Yuhai; Chen, Zhanghuang; Liu, Ping; Huang, Jian; Lao, Lixing

    2013-01-01

    Objective. To determine the effects of the moxa smoke on human heart rate (HR) and heart rate variability (HRV). Methods. Fifty-five healthy young adults were randomly divided into experimental (n = 28) and control (n = 27) groups. Experimental subjects were exposed to moxa smoke (2.5 ± 0.5?mg/m3) twice for 25 minutes in one week. ECG monitoring was performed before, during, and after exposure. Control subjects were exposed to normal indoor air in a similar environment and similarly monitored. Followup was performed the following week. Short-term (5?min) HRV parameters were analyzed with HRV analysis software. SPSS software was used for statistical analysis. Results. During and after the first exposure, comparison of percentage changes or changes in all parameters between groups showed no significant differences. During the second exposure, percentage decrease in HR, percentage increases in lnTP, lnHF, lnLF, and RMSSD, and increase in PNN50 were significantly greater in the experimental group than in control. Conclusion. No significant adverse HRV effects were associated with this clinically routine 25-minute exposure to moxa smoke, and the data suggests that short-term exposure to moxa smoke might have positive regulating effects on human autonomic function. Further studies are warranted to confirm these findings. PMID:23762143

  15. A Research of Physical Activity's Influence on Heart Rate Using Feedforward Neural Network

    Microsoft Academic Search

    Feng Xiao; Ming Yuchi; Jun Jo; Ming-yue Ding; Wen-guang Hou

    2009-01-01

    Heart rate (HR) signal analysis is widely used in the medicine and medical research area. Physical activities (PA) are commonly\\u000a recognized to greatly affect the changes of heart rate. However, the direct relationship between heart rate and physical activities\\u000a is hard to describe. In this paper, a model using feedforward neural network with the function of HR prediction is designed.

  16. Noninvasive Sudden Death Risk Stratification: Heart Rate Variability and Turbulence, and QT Dynamicity

    Microsoft Academic Search

    Antonio Vincenti; Stefano Pedretti

    Variability in sinus-rhythm pacemaker activity over time is a major physiological characteristic of heart-rate behavior, and\\u000a many cardiovascular and metabolic conditions result in a change in heart rate variability. The numerous studies of time- and\\u000a frequency-dependent variability have improved our knowledge of the physiological and pathological patterns of heart-rate variability\\u000a (HRV). The standard deviation of 24-h mean RR value (SDNN),

  17. Changes in heart rate recovery in response to acute changes in training load

    Microsoft Academic Search

    Jill Borresen; Michael I. Lambert

    2007-01-01

    Heart rate recovery is an indirect marker of autonomic function and changes therein may offer a practical way of quantifying\\u000a the physiological effects of training. We assessed whether per cent heart rate recovery (HRr%) after a standardized sub-maximal\\u000a running (Heart rate Interval Monitoring System: HIMS) test, changed with acute changes in training load. A total of 28 men\\u000a and women

  18. MODELING THE ASSOCIATION BETWEEN HEART RATE VARIABILITY AND ILLNESS IN ELITE SWIMMERS

    E-print Network

    Paris-Sud XI, Université de

    MODELING THE ASSOCIATION BETWEEN HEART RATE VARIABILITY AND ILLNESS IN ELITE SWIMMERS Philippe;43(6):1063-70" DOI : 10.1249/MSS.0b013e318204de1c #12;ABSTRACT Purpose: To determine whether heart rate variability (high frequency- HF; 0.15 Hz-0.40Hz, low frequency-LF; 0.04-0.15 Hz and HF/LF ratio) of heart rate

  19. A Dynamic Heart Rate Prediction Model for Training Optimization in Cycling (P83)

    Microsoft Academic Search

    Ankang Le; Thomas Jaitner; Frank Tobias; Lothar Litz

    Heart rate can be considered as a reliable indicator of the physiological load both for immediate training monitoring and\\u000a for post-training analysis in cycling. The aim of this paper is to present a dynamic heart rate prediction model which will\\u000a be used by a model predictive controller to optimize the cycling training. This model predicts the heart rate of a

  20. Early ventilation-heart rate breakpoint during incremental cycling exercise.

    PubMed

    Gravier, G; Delliaux, S; Ba, A; Delpierre, S; Guieu, R; Jammes, Y

    2014-03-01

    Previous observations having reported a transient hypoxia at the onset of incremental exercise, we investigated the existence of concomitant ventilatory and heart rate (HR) breakpoints.33 subjects executed a maximal cycling exercise with averaging for successive 5-s periods of HR, ventilation, tidal volume (VT), mean inspiratory flow rate (VT/Ti), and end-tidal partial pressures of O2 (PETO2) and CO2. In 10 subjects, the transcutaneous partial pressure of O2 (PtcO2) was recorded and the venous blood lactic acid (LA) concentration measured.At the beginning of exercise, PETO2 decreased, reaching a nadir, then progressively increased until the exercise ended. PtcO2 varied in parallel. Whether or not a 0-W cycling period preceded the incremental exercise, the rate of changes in VE, VT, VT/Ti and HR significantly increased when the nadir PO2 was reached. The ventilatory/ HR breakpoint was measured at 33±4% of VO2max, whereas the ventilatory threshold (VTh) was detected at 67±4% of VO2max and LA began to increase at 45 to 50% of VO2max.During incremental cycling exercise, we identified the existence of HR and ventilatory breakpoints in advance of both lactate and ventilatory thresholds which coincided with modest hypoxia and hypercapnia. PMID:23945972

  1. GENETIC AND MATERNAL ENVIRONMENTAL INFLUENCES ON EMBRYONIC PHYSIOLOGY: INTRASPECIFIC VARIABILITY IN AVIAN EMBRYONIC HEART RATES

    Microsoft Academic Search

    W. W. BURGGRI; H. TAZAWA

    The heart rate of embryos of altricial pigeons (Columba domesticui and hank swallows (Riparia riparia) was measured on a daily basis to investigate inrerclutch versus intracl utch variabi lity in heart rate during development. In both pigeons and swallows, the developmental patterns of he an rate change in siblings (i.e., embryos from the same clutch) are statistically much more similar

  2. Thermal Acclimation of Heart Rates in Reptilian Embryos Wei-Guo Du1,2,4

    E-print Network

    Shine, Rick

    Thermal Acclimation of Heart Rates in Reptilian Embryos Wei-Guo Du1,2,4 *, Hua Ye1 , Bo Zhao1-standing puzzle in reptilian developmental biology: Do the metabolic and developmental rates of embryos acclimate, Shine R (2010) Thermal Acclimation of Heart Rates in Reptilian Embryos. PLoS ONE 5(12): e15308. doi:10

  3. Pharmacological properties of blood pressure and heart rate control in suncus.

    PubMed

    Matsuki, N; Sakuma, Y; Saito, H

    1993-05-01

    Blood pressure and heart rate and responses to various physiological substances in suncus were characterized and compared with those in mice. The blood pressures of the two species were similar, but the heart rate of suncus (about 400 beat/min) was significantly lower than that of mice. Norepinephrine increased the blood pressure but decreased the heart rate in suncus. The latter was blocked by cervical vagotomy. Sensitivities to acetylcholine and isoproterenol were lower in suncus. These results suggest that regulation of blood pressure and heart rate in suncus is very unique and different from the well-defined system of the rodents. PMID:8341030

  4. Changes in Heart Rate Variability after Coronary Artery Bypass Grafting and Clinical Importance of These Findings

    PubMed Central

    Lakusic, Nenad; Mahovic, Darija; Cerkez Habek, Jasna; Novak, Miroslav; Cerovec, Dusko

    2015-01-01

    Heart rate variability is a physiological feature indicating the influence of the autonomic nervous system on the heart rate. Association of the reduced heart rate variability due to myocardial infarction and the increased postinfarction mortality was first described more than thirty years ago. Many studies have unequivocally demonstrated that coronary artery bypass grafting surgery generally leads to significant reduction in heart rate variability, which is even more pronounced than after myocardial infarction. Pathophysiologically, however, the mechanisms of heart rate variability reduction associated with acute myocardial infarction and coronary artery bypass grafting are different. Generally, heart rate variability gradually recovers to the preoperative values within six months of the procedure. Unlike the reduced heart rate variability in patients having sustained myocardial infarction, a finding of reduced heart rate variability after coronary artery bypass surgery is not considered relevant in predicting mortality. Current knowledge about changes in heart rate variability in coronary patients and clinical relevance of such a finding in patients undergoing coronary artery bypass grafting are presented.

  5. On the open/close performance of prosthetic heart valves at high frequencies

    NASA Astrophysics Data System (ADS)

    Beltran, A.; Zenit, R.

    2013-11-01

    We report experimental observations of the performance of mechanical and biological prosthetic heart valves. The valves are mounted in a test circular channel conected to a flow system that emulates accelerated human-like conditions. The flow is generated by a high frequencie pulsative pump (in the range of 7 to 18 Hz). The objective of the investigation is to find the treshold conditions for which the open/close performance fails. Preliminary results show that for the mechanical valve the failure starts at 436 pulses/min, while for the biological valve, it starts a failing performance is observed for frequencies higher that 462 pulses/min. Even though these values are far from the heart rate in the human body, we use these measurements to further understand the structure-fluid interaction mechanics of the flow through heart valves.

  6. Higher Precision of Heart Rate Compared with VO2 to Predict Exercise Intensity in Endurance-Trained Runners.

    PubMed

    Reis, Victor M; den Tillaar, Roland Van; Marques, Mario C

    2011-01-01

    The aim of the present study was to assess the precision of oxygen uptake with heart rate regression during track running in highly-trained runners. Twelve national and international level male long-distance road runners (age 30.7 ± 5.5 yrs, height 1.71 ± 0.04 m and mass 61.2 ± 5.8 kg) with a personal best on the half marathon of 62 min 37 s ± 1 min 22 s participated in the study. Each participant performed, in an all-weather synthetic track five, six min bouts at constant velocity with each bout at an increased running velocity. The starting velocity was 3.33 m·s(-1) with a 0.56 m·s(-1) increase on each subsequent bout. VO2 and heart rate were measured during the runs and blood lactate was assessed immediately after each run. Mean peak VO2 and mean peak heart rate were, respectively, 76.2 ± 9.7 mL·kg(-1)·min(-1) and 181 ± 13 beats·min(-1). The linearity of the regressions between heart rate, running velocity and VO2 were all very high (r > 0.99) with small standard errors of regression (i.e. Sy.x < 5% at the velocity associated with the 2 and 4 mmol·L(-1) lactate thresholds). The strong relationships between heart rate, running velocity and VO2 found in this study show that, in highly trained runners, it is possible to have heart rate as an accurate indicator of energy demand and of the running speed. Therefore, in this subject cohort it may be unnecessary to use VO2 to track changes in the subjects' running economy during training periods. Key pointsHeart rate is used in the control of exercise intensity in endurance sports.However, few studies have quantified the precision of its relationship with oxygen uptake in highly trained runners.We evaluated twelve elite half-marathon runners during track running at various intensities and established three regressions: oxygen uptake / heart rate; heart rate / running velocity and oxygen uptake / running velocity.The three regressions presented, respectively, imprecision of 4,2%, 2,75% and 4,5% at the velocity associated with the 4 mmol·L(-1) threshold.The results of the present study show that, in highly trained runners, it is possible to use heart rate as an accurate index of the external work rate during sub maximal running speeds. PMID:24149310

  7. Docosahexaenoic acid-rich fish oil improves heart rate variability and heart rate responses to exercise in overweight adults.

    PubMed

    Ninio, Daniel M; Hill, Alison M; Howe, Peter R; Buckley, Jonathan D; Saint, David A

    2008-11-01

    Dietary fish oil supplementation and regular physical activity can improve outcomes in patients with established CVD. Exercise has been shown to improve heart rate variability (HRV), a predictor of cardiac death, but whether fish oil benefits HRV is controversial. Obese adults at risk of future coronary disease have impaired HRV and may benefit from these interventions. We evaluated the effect of DHA-rich tuna fish oil supplementation with and without regular exercise on HRV in sedentary, overweight adults with risk factors for coronary disease. In a randomised, double-blind, parallel comparison, sixty-five volunteers consumed 6 g fish oil/d (DHA 1.56 g/d, EPA 0.36 g/d) or sunflower-seed oil (placebo) for 12 weeks. Half of each oil group also undertook regular moderate physical activity (3 d/week for 45 min, at 75 % of age-predicted maximal heart rate (HR)). Resting HR and the HR response to submaximal exercise were measured at weeks 0, 6 and 12. In forty-six subjects, HRV was also assessed by power spectrum analysis of 20 min electrocardiogram recordings taken supine at baseline and 12 weeks. Fish oil supplementation improved HRV by increasing high-frequency power, representing parasympathetic activity, compared with placebo (P = 0.01; oil x time interaction). It also reduced HR at rest and during submaximal exercise (P = 0.008; oil x time interaction). There were no significant fish oil x exercise interactions. Dietary supplementation with DHA-rich fish oil reduced HR and modulated HRV in keeping with an improved parasympathetic-sympathetic balance in overweight adults with risk factors for future coronary disease. PMID:18339222

  8. Synchronization of Heart Rates and Geomagnetic Field Variations: A Pilot Study

    NASA Astrophysics Data System (ADS)

    Zenchenko, Tatjana; Jordanova, Malina; Poskotinova, Lilia; Medvedeva, Anna; Uzunov, Todor; Alenikova, Alexandra; Breus, Tamara

    2013-12-01

    The project "Heliobiology" (2011 - 2015) reflects the intense interest towards the influence of solar activity on the human health. One of its tasks is to study the putative relationship between geomagnetic activity and the changes of heart rate variability in healthy volunteers. The paper presents the first results from 5 simultaneous experiments performed in 2013 at 3 different latitudes - Sofia, Moscow and Arkhangelsk. The aim of the experiment is to study the degree of conjugation of the heart rate variability with the variations of the geomagnetic field. To minimize the experimental bias one and the same hard- and software is applied during the testing. ECG signals are recorder via "KARDI-2"; the software package is "Ecosan-2007", both developed by "Medical Computer Systems", Zelenograd, Russia. The duration of the observations ranged from 60 to 100 minutes. A comparison of the dynamics of the minute variations of the heart rate with the horizontal components of the geomagnetic field vector has revealed a synchronization of the research parameters. Further experiments are planned in the years to come to confirm the results in a larger experimental group.

  9. Heart rate and blood lactate responses to changquan and daoshu forms of modern wushu.

    PubMed

    Ribeiro, Jerri Luiz; de Castro, Bruno Ogoday S D; Rosa, Caio S; Baptista, Rafael R; Oliveira, Alvaro R

    2006-01-01

    The development of specific training designed to enhance physiological aspects of performance relies heavily on the availability of accurate and validity physiological data. In the combat sport of Wushu, katas are used to develop aerobic fitness. It is arguably important to assess and monitor heart rate (HR) and lactate (La) responses when designing effective training programs. The aim of this pilot study was to investigate heart rate and lactate responses to forms execution among Wushu combatants. Male elite modern Wushu athletes (n = 4) from a South Brazilian regional team participated in the study. Athletes were aged 22.5 ± 2.08 years old and had at least eight years of Wushu experience. Athletes carried out the Changquan and Daoshu forms in random order, HR and La were measured pre- and post-exercise. Results indicate that HR was 176 ± 3 and 176 ± 2 bpm and La was 4.38 ± 1.3 and 5.15 ± 1.07 mmol·l(-1) for Changquan and Daoshu forms, respectively. There were no significantly differences in HR and La between the two forms. HR values represent 89.2 ± 1.1 and 89.1 ± 1.8% of age-predicted maximal heart rate and lactate was near of 4 mmol·l(-1) point. In conclusion, training programs to Wushu combatants could target the range of physiological values cited above with no differences between two forms. Key PointsHeart rate and lactate responses are not significantly different between Changquan and Daoshu forms for Wushu combatants.The Wushu katas could be used to develop aerobic fitness. PMID:24357970

  10. AKAP10 (I646V) functional polymorphism predicts heart rate and heart rate variability in apparently healthy, middle-aged European-Americans

    Microsoft Academic Search

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

    2009-01-01

    Previous evidence suggests that the dual-specific A kinase-anchoring protein 2 functional polymorphism (AKAP10 (A\\/G) I646V) influences heart rate (HR) and heart rate variability (HRV) in mice and humans (N 5 122) with cardiovascular disease. Here, we asked whether this AKAP10 variant predicts HR and HRV in a large sample of healthy humans. Resting HR and short-term time and frequency domain

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

    PubMed Central

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

    2009-01-01

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

  12. Resting heart rate in patients with ischemic heart disease in Saudi Arabia and Egypt

    PubMed Central

    Kinsara, Abdulhalim J.; Najm, Hani K.; Anazi, Menwar Al; Tamim, Hani

    2011-01-01

    Aim To assess the level of resting heart rate (RHR) in an outpatient population presenting with stable coronary artery disease (CAD) as well as to measure its association with current therapeutic management strategies for cardiovascular events. Materials and methods A multi-center cross-sectional survey was carried out in Saudi Arabia and Egypt over a three month period (between January 2007 and April 2007). 2049 patients with CAD without clinical heart failure (HF) were included in this study through “cluster sampling”. RHR was measured by manual palpitation. Results Mean age of CAD patients was 56.7 ± 10.4 and the mean RHR was 78.9 ± 13.9 b/m. 1686 patients (83.1%) were on ?-blockers for whom the RHR was 78.5 ± 14.0 b/m (95.5% had RHR ? 60 b/m, which is higher than recommended by the guidelines). 1094 (73.5%) of patients on ?-blockers were on a lower dose, probably to avoid the complications associated with such a class. Among those not on ?-blockers (16.9%), RHR was 80.9 ± 13.0 b/m. Moreover, 98 patients (4.8%) were on calcium channel blocker (diltiazem or verapamil) but not on ?-blockers, for whom the RHR was 80.9 ± 12.0 b/m. Finally, 163 patients (8.0%) were on both ?-blockers and the calcium channel blocker, and their RHR was 79.0 ± 14.4 b/m. Conclusion Optimal target RHR has not been achieved in a significant number of screened patients. Achievements of such targets are known to decrease mortality and to improve survival. PMID:23960653

  13. The Association between Heart Rate and Blood Pressure, Blood Lipids and Other Cardiovascular Risk Factors

    Microsoft Academic Search

    Goya Wannamethee; A. Gerald Shaper

    1994-01-01

    Background: Several studies have shown that an elevated heart rate is associated with an increased risk of ischaemic heart disease. The aim of this study was to examine the relationship between heart rate, blood pressure, blood lipids and other cardiovascular risk factors in middle-aged men.Methods: A total of 7735 men, aged 40–59 years at screening, were selected at random from

  14. Fish Consumption, Sleep, Daily Functioning, and Heart Rate Variability

    PubMed Central

    Hansen, Anita L.; Dahl, Lisbeth; Olson, Gina; Thornton, David; Graff, Ingvild E.; Frøyland, Livar; Thayer, Julian F.; Pallesen, Staale

    2014-01-01

    Study Objectives: This study investigated the effects of fatty fish on sleep, daily functioning and biomarkers such as heart rate variability (HRV), vitamin D status (serum 25-hydroxyvitamin D (25OHD), and eicosapentaenoic acid (EPA, 20:5n-3) + docosahexaenoic acid (DHA, 22:6n-3) in red blood cells. Moreover the relationship among sleep, daily functioning, HRV, vitamin D status, and levels of EPA+DHA was investigated. Methods: Ninety-five male forensic patients from a secure forensic inpatient facility in the USA were randomly assigned into a Fish or a Control group. The Fish group received Atlantic salmon three times per week from September to February, and the Control group was provided an alternative meal (e.g., chicken, pork, beef), but with the same nutritional value as their habitual diet, three times per week during the same period. Sleep (sleep latency, sleep efficiency, actual sleep time, and actual wake time), self-perceived sleep quality and daily functioning, as well as vitamin D status, EPA+DHA, and HRV, were assessed pre- and post-intervention period. Results: There was a significant increase in sleep latency from pre- to post-test in the Control group. The Fish group reported better daily functioning than the Control group during post-test. Fish consumption throughout the wintertime had also an effect on resting HRV and EPA+DHA, but not on vitamin D status. However, at post-test, the vitamin D status in the Fish group was still closer to the level regarded as optimal compared to the Control group. Vitamin D status correlated negatively with actual wake time and positively with sleep efficiency during pre-test, as well as positively with daily functioning and sleep quality during post-test. Finally, HRV correlated negatively with sleep latency and positively with daily functioning. Conclusions: Fish consumption seemed to have a positive impact on sleep in general and also on daily functioning, which may be related to vitamin D status and HRV. Citation: Hansen AL, Dahl L, Olson G, Thornton D, Graff IE, Frøyland L, Thayer JF, Pallesen S. Fish consumption, sleep, daily functioning, and heart rate variability. J Clin Sleep Med 2014;10(5):567-575. PMID:24812543

  15. Development of a piezopolymer pressure sensor for a portable fetal heart rate monitor

    NASA Technical Reports Server (NTRS)

    Zuckerwar, A. J.; Pretlow, R. A.; Stoughton, J. W.; Baker, D. A.

    1993-01-01

    A piezopolymer pressure sensor has been developed for service in a portable fetal heart rate monitor, which will permit an expectant mother to perform the fetal nonstress test, a standard predelivery test, in her home. Several sensors are mounted in an array on a belt worn by the mother. The sensor design conforms to the distinctive features of the fetal heart tone, namely, the acoustic signature, frequency spectrum, signal amplitude, and localization. The components of a sensor serve to fulfill five functions: signal detection, acceleration cancellation, acoustical isolation, electrical shielding, and electrical isolation of the mother. A theoretical analysis of the sensor response yields a numerical value for the sensor sensitivity, which is compared to experiment in an in vitro sensor calibration. Finally, an in vivo test on patients within the last six weeks of term reveals that nonstress test recordings from the acoustic monitor compare well with those obtained from conventional ultrasound.

  16. The influence of ventilatory control on heart rate variability in children

    Microsoft Academic Search

    Craig A. Williams; Philippe Lopes

    2002-01-01

    The aim of this study was to determine the influence of breathing frequency and tidal volume on resting heart rate variability in children aged 9 years ( n = 29) and 16 years ( n = 19). Heart rate variability was measured in four conditions: (1) without the control of ventilation followed at random by (2) a fixed breathing frequency

  17. Heart rate variability: sleep stage, time of night, and arousal influences

    Microsoft Academic Search

    M. H. Bonnet; D. L. Arand

    1997-01-01

    Spectral analysis was used to assess heart rate variability in consecutive 5-min epochs during the night in 12 normal adults. Simultaneous time coding of EEG and digitized EKG allowed examination of heart rate variability as a function of sleep stage, time of night and presence of EEG arousal. The results replicated previous studies in showing increases in high frequency components

  18. Heart rate variability analysis for arterial hypertension etiological diagnosis during surgical procedures under tourniquet

    Microsoft Academic Search

    R. Logier; J. De jonckheere; M. Delecroix; A. Keribedj; M. Jeanne; R. Jounwaz; B. Tavernier

    2011-01-01

    Pneumatic tourniquets are widely used to provide a bloodless operative field during upper or lower limb surgery. If tourniquet inflation during general anesthesia is initially a mild stimulus, a long duration of inflation can imply heart rate and blood pressure increasing. However, heart rate or blood pressure increasing can also be caused by other external stimuli. Indeed, in the case

  19. Resting Enhanced Frequency Domain Analysis Improves Heart Rate Variability Sensitivity in Early and Late Diabetics

    Microsoft Academic Search

    A. I. Vinik; B. Aysin; J. Colombo

    Background: The addition of frequency domain (FD) analysis of respiratory activity to FD of heart rate variability (HRV) is necessary to independently and simultaneously analyze both autonomic (ANS) branches non-invasively and quantitatively. This method has been presented as the enhanced FD analysis (EFDA) approach. Our clinical results have shown that EFDA improves FD heart rate variability (fdHRV) sensitivity in early

  20. Using Heart Rate Monitors in Research on Fitness Levels of Children in Physical Education.

    ERIC Educational Resources Information Center

    Strand, Brad; Reeder, Steve

    1993-01-01

    Demonstrates the use of heart rate monitors (HRMs) in fitness research and examines heart rate intensity levels of middle school students while they participated in a variety of physical education activities throughout a school year. Research shows the HRM has considerable potential in assessing fitness achievements in school-age children. (GLR)

  1. HEART RATE AND BLOOD PRESSURE VARIABILITY UNDER MOON, MARS AND ZERO GRAVITY CONDITIONS DURING PARABOLIC FLIGHTS

    E-print Network

    HEART RATE AND BLOOD PRESSURE VARIABILITY UNDER MOON, MARS AND ZERO GRAVITY CONDITIONS DURING), studied via the heart rate variability (HRV) and blood pressure variability (BPV). HRV and BPV were assessed via classical time and frequency domain measures. Mean systolic and dias- tolic blood pressure

  2. Heart Rate Characteristics: Novel Physiomarkers to Predict Neonatal Infection and Death

    Microsoft Academic Search

    M. Pamela Griffin; Douglas E. Lake; Eric A. Bissonette; Frank E. Harrell; T. Michael O'Shea; J. Randall Moorman

    2005-01-01

    ABSTRACT. Objective. Monitoring of,regulated physiologic processes using physiomarkers such as heart rate variability may be important in the early diagnosis of subacute, potentially catastrophic illness. Early in the course of neonatal sepsis, there are physiomarkers of reduced heart rate variability and transient decelerations similar to fetal distress. The goal of this study was to determine the degree of increased risk

  3. Neuron, Vol. 20, 103114, January, 1998, Copyright 1998 by Cell Press Abnormal Heart Rate Regulation

    E-print Network

    Clapham, David E.

    Loewi et al. first demonstrated in 1926 that acetylcho- line (ACh) secreted from the vagus nerve mediates the Acetylcholine (ACh) released from the stimulated va- decrease in heart rate and contractility (Loewi and Nav- gus nerve decreases heart rate via modulation of sev- ratil, 1926). After more than 70

  4. Heart rate as a sublethal indicator of thermal stress in juvenile freshwater mussels

    Microsoft Academic Search

    Tamara J. Pandolfo; W. Gregory Cope; Consuelo Arellano

    2009-01-01

    Freshwater mussels (Unionoida) are one of the most sensitive and rapidly declining faunal groups in the world. Rising water temperatures, caused by industrial discharges, land development, or climate change can further challenge threatened unionid communities. The direct relationship between heart rate and temperature in ectotherms enables the use of heart rate as an indicator of whole-animal thermal stress. The purpose

  5. Electrocardiogram signal processing method for exact Heart Rate detection in physical activity monitoring system: Wavelet approach

    Microsoft Academic Search

    Uk Jin Yoon; Yeon Sik Noh; Young Myeon Han; Min Yong Kim; Jae Hoon Jung; In Seop Hwang; Hyung Ro Yoon; In Cheol Jeong

    2010-01-01

    Physical Activity Monitoring is a device that can measure the human activity quantity quantitatively through Heart Rate detection in real time. R-Spike detection of ECG is required for this Heart Rate detection. Since Physical Activity Monitoring System is usually used during activity or exercise, however, signal measured in ECG System is contaminated by diverse noises. Diverse noises become the factors

  6. Heart rate variability characterization in daily physical activities using wavelet analysis and multilayer fuzzy activity clustering

    Microsoft Academic Search

    Hsiao-Lung Chan; Shih-Chin Fang; Yu-Lin Ko; Ming-An Lin; Hui-Hsun Huang; C.-H. Lin

    2006-01-01

    A portable data recorder was developed to parallel measure the electrocardiogram and body accelerations. A multilayer fuzzy clustering algorithm was proposed to classify the physical activity based on body accelerations. Discrete wavelet transform was incorporated to retrieve time-varying characteristics of heart rate variability under different physical activities. Nine healthy subjects were included to investigate activity-related heart rate variability during 24

  7. Modeling the dynamic response of camels' heart rate to physical activities

    Microsoft Academic Search

    Techane Bosona; Girma Gebresenbet; Fufa S. Bulitta

    2011-01-01

    This paper presents the result of the study made on the dynamic response of camels' heart rate (HR) under working conditions. The main objective was to develop a simulation model that can describe the dynamic nature of the camels' heart rate response to physical activity i.e. pulling a loaded cart and sledge. The dynamic simulation model was developed using Powersim

  8. Salivary THC following cannabis smoking correlates with subjective intoxication and heart rate

    Microsoft Academic Search

    David B. Menkes; Richard C. Howard; George F. S. Spears; Eric R. Cairns

    1991-01-01

    A cannabis smoking trial was conducted using paid volunteers. Subjective intoxication, measured using a visual analogue scale, was compared with heart rate and with salivary delta-9-tetrahydrocannabinol (THC) levels at various times after smoking a cigarette containing 11 mg THC. Subjective intoxication and heart rate elevation were significantly correlated with the log of salivary THC. Salivary THC levels are a sensitive

  9. Effects of shift work on QTc interval and blood pressure in relation to heart rate variability

    Microsoft Academic Search

    Katsuyuki Murata; Eiji Yano; Hideki Hashimoto; Kanae Karita; Miwako Dakeishi

    2005-01-01

    Objectives: There is evidence that shift work contributes to excess cardiovascular mortality. The purpose of this study was to determine the effects of shift work on heart rate-corrected QT (QTc) and blood pressure in relation to heart rate variability (CVRR). Methods: The study population consisted of 153 male shiftworkers and 87 male day workers who were employed at a copper-smelting

  10. Monitoring of the vegetative background of sleep by means of spectral analysis of heart rate variability

    Microsoft Academic Search

    Udo J. Scholz; Anna M. Bianchi; Sergio Cerutti; Stanislav Kubicki

    1993-01-01

    From the ECG trace of the sleep polygrams the heart rate variability (HRV) is derived by determining the intervals between the R peaks. During sleep, transitions of heart rate can be observed in HRV signal which are relevant to changes in the autonomic regulation. For better insight into the vegetative background of sleep, the spectrum analysis of HRV signal and

  11. A method for foetal heart rate monitoring during magnetic resonance imaging using Doppler ultrasound

    Microsoft Academic Search

    Simon A Shakespeare; Rachel J Moore; John A Crowe; Penny A Gowland; Barrie R Hayes-Gill

    1999-01-01

    A means of monitoring foetal heart rate (FHR) during magnetic resonance imaging (MRI) is presented. Foetal heart rate was measured using a modified standard Doppler ultrasound based monitor. The transducer and lead from the monitor required alteration to reduce interference and distortion in the MR images to acceptable levels. These changes enabled high quality images to be produced with insignificant

  12. Two-Dimensional Ultrasonic Strain Rate Measurement of the Human Heart in Vivo

    E-print Network

    Konofagou, Elisa E.

    Two-Dimensional Ultrasonic Strain Rate Measurement of the Human Heart in Vivo Jan D'hooge1 , Fadi, the feasibility of two-dimensional strain rate estimation of the human heart in vivo is shown. To do this on myocardial velocity imaging, i.e. Doppler myocardial imaging [2]. This methodology has been validated both

  13. Towards higher accuracy and better noise-tolerance for fetal heart rate monitoring using Doppler ultrasound

    Microsoft Academic Search

    Chang Su Lee; Martin Masek; Chiou Peng Lam; Keng Tiong Tan

    2009-01-01

    Doppler ultrasound monitors are commonly used to measure the fetal heart rate (FHR) in routine screenings. They are less intrusive than fetal electrocardiography (FECG), but are more prone to noise and thus seen as less accurate devices. Recent developments resulted in beat-to-beat heart rate algorithms for Doppler shift monitors that claimed to approach the accuracy of that obtained from direct

  14. Heart Rate and Treatment Effect in Children with Disruptive Behavior Disorders

    ERIC Educational Resources Information Center

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

    2008-01-01

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

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

    ERIC Educational Resources Information Center

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

    2011-01-01

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

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

    ERIC Educational Resources Information Center

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

    2011-01-01

    The study of heart rate variability is an important tool for a noninvasive evaluation of the neurocardiac integrity. The present study aims to evaluate the autonomic heart rate modulation in supine and standing positions in 12 children diagnosed with cerebral palsy and 16 children with typical motor development (control group), as well as to…

  17. Detrended Fluctuation Analysis of Heart Rate Variability in Normal and Growth-Restricted Fetuses

    Microsoft Academic Search

    Akihiko Kikuchi; Nobuya Unno; Shiro Kozuma; Yuji Taketani

    2008-01-01

    Background: Detrended fluctuation analysis (DFA) has recently been validated as an excellent method by which to analyze heart rate variability and distinguish healthy subjects from patients with various types of the cardiac nervous system dysfunction. Methods: One hundred and nineteen fetal heart rate (FHR) recordings obtained from healthy normal fetuses and 68 recordings obtained from small-for-gestational-age (SGA) fetuses were analyzed

  18. The relationship between power output and heart rate in ducks diving voluntarily

    Microsoft Academic Search

    Lowell T. McPhail; David R. Jones

    1998-01-01

    Heart rate in response to natural and induced changes in power output was monitored in ducks diving voluntarily to a depth of 1.2 m. Adult lesser scaup (Aythya affinis) (3 female, 2 male), were trained to make shallow dives in an indoor tank (1.2 m depth) to obtain food. Heart rate was monitored using telemetry, and was determined for the

  19. Relations between the development of patterns of sleeping heart rate and body temperature in infants

    Microsoft Academic Search

    S A Petersen; C Pratt; M P Wailoo

    2001-01-01

    Overnight patterns of rectal temperature and heart rate were recorded from 119 normal infants at weekly intervals from 7 to about 16 weeks of age. All data were collected in the infants' own homes. As previously reported, different infants developed an adult-like night time rectal temperature pattern abruptly at different ages. When heart rate data were collated by age, there

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

    ERIC Educational Resources Information Center

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

    2009-01-01

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

  1. Children's, Adolescents', and Young Adults' Heart Rate Reactivity to, and Recovery from, a Brief Psychological Stressor.

    ERIC Educational Resources Information Center

    Sharpley, Christopher F.

    1992-01-01

    Examined the effects of stress related to a competitive arithmetic test on a group of 301 children and young adults in 7 age cohorts ranging from 7 to 20 years by measuring changes in heart rate. Discovered some age and sex differences, and found that the oldest group had the greatest increase in heart rate. (MDM)

  2. A Novel Methodology for Fetal Heart Rate Extraction from the Abdominal Electrocardiogram

    Microsoft Academic Search

    M. Ayat; K. Assaleh; H. Al-Nashash

    2008-01-01

    This paper proposes an automated methodology for extracting fetal heart rate from single cutaneous potential abdominal signal. The proposed method calculates fetal heart rate in three steps. First, two-tier method based on singular value decomposition and polynomial classifiers is applied to the abdominal signal to separate the fetal ECG and the maternal ECG. Second, the fetal R-peaks are detected from

  3. Heart Rate Level and Antisocial Behavior in Children and Adolescents: A Meta-Analysis

    ERIC Educational Resources Information Center

    Ortiz, Jame; Raine, Adrian

    2004-01-01

    Objective: To assess whether antisocial children are characterized by low heart rate. Method: A meta-analysis was conducted on 45 independent effect sizes of the resting heart rate-antisocial behavior relationship obtained from 40 studies meeting inclusion and exclusion criteria. Studies were conducted between 1971 to 2002 using a total of 5,868…

  4. Relation between QT interval and heart rate. New design of physiologically adaptive cardiac pacemaker

    Microsoft Academic Search

    A F Rickards; J Norman

    1981-01-01

    The relation between QT interval and heart rate has been studied in a group of patients undergoing physiological exercise, in a group undergoing atrial pacing without exercise, and in a group with complete heart block undergoing exercise at a fixed ventricular rate controlled by cardiac pacing. The expected shortening in QT interval during physiological exercise is only in part the

  5. Sensitivity and reproducibility of accelerometry and heart rate in physical strain assessment during prosthetic gait

    Microsoft Academic Search

    Johannes B. J. Bussmann; Hendrika J. G. van den Berg-Emons; Sonia M. Angulo; Theo Stijnen; Henk J. Stam

    2004-01-01

    Accelerometry and heart rate (HR) are frequently used indicators of physical strain during normal daily life. The present study focused on the sensitivity and reproducibility of accelerometry (body motility, the intensity of body movement measured with accelerometry) and HR (percentage maximal heart rate reserve, %HRR max) in the assessment of physical strain during walking in persons with a lower leg

  6. A Noninvasive Radiotelemetry System to Monitor Heart Rate for Assessing Stress Responses of Bovines

    Microsoft Academic Search

    Alan M. Lefcourt; Benny Erez; Mark A. Varner; Ruth Barfield; Uri Tasch

    1999-01-01

    A noninvasive radiotelemetry system was deve- loped to monitor heart rates of cows and to view and analyze data. The system was validated by comparing heart rate data of two restrained heifers collected simultaneously using telemetric and direct elec- trocardiogram measurements and by acquiring data over 72 h from two dry cows housed in an experimen- tal handling facility consisting

  7. The effect of agonistic interactions on the heart rate of group-housed sows

    Microsoft Academic Search

    Jeremy N. Marchant; Michael T. Mendl; Andrew R. Rudd; Donald M. Broom

    1995-01-01

    Inter-sow aggression can be a major welfare problem in group-housing systems and can also affect productivity. This experiment investigated the effect of different types of agonistic interaction using heart rate as an indicator of physiological response. The heart rates of nine Large White × Landrace sows housed in a large group with an electronic sow feeder system, were monitored during

  8. Effects of Biofeedback Training on Voluntary Heart Rate Control During Dynamic Exercise

    Microsoft Academic Search

    Maria Álvarez Moleiro; Francisco Villamarín Cid

    2001-01-01

    The aims of this study were to (1) compare the effect of biofeedback with that of verbal instructions on the control of heart rate during exercise on a treadmill, (2) test the possible effect of workload on this control, and (3) examine the effect of workload on baseline heart rate at rest and during exercise. The study involved 35 participants

  9. Does Baseline Heart Rate Variability Reflect Stable Positive Emotionality?

    PubMed

    Silvia, Paul J; Jackson, Bryonna A; Sopko, Rachel S

    2014-11-01

    Several recent studies have found significant correlations, medium in effect size, between baseline heart rate variability (HRV) and measures of positive functioning, such as extraversion, agreeableness, and trait positive affectivity. Other research, however, has suggested an optimal level of HRV and found nonlinear effects. In the present study, a diverse sample of 239 young adults completed a wide range of measures that reflect positive psychological functioning, including personality traits, an array of positive emotions (measured with the Dispositional Positive Emotions Scale), and depression, anxiety, and stress symptoms (measured with the DASS and CESD). HRV was measured with a 6-minute baseline period and quantified using many common HRV metrics (e.g., respiratory sinus arrhythmia, root mean square of successive differences, and others), and potentially confounding behavioral and lifestyle variables (e.g., BMI, caffeine and nicotine use, sleep quality) were assessed. Neither linear nor non-linear effects were found, and the effect sizes were small and near zero. The findings suggest that the cross-sectional relationship between HRV and positive experience deserves more attention and meta-analytic synthesis. PMID:25147421

  10. Changes in heart rate in the first minutes after birth.

    PubMed

    Dawson, J A; Kamlin, C O F; Wong, C; te Pas, A B; Vento, M; Cole, T J; Donath, S M; Hooper, S B; Davis, P G; Morley, C J

    2010-05-01

    The normal range of heart rate (HR) in the first minutes after birth has not been defined. Objective To describe the HR changes of healthy newborn infants in the delivery room (DR) detected by pulse oximetry. Study Design All 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 medical intervention in the DR including supplemental oxygen, or respiratory support. HR was measured using a pulse oximeter (PO) with the sensor applied to the right hand or wrist immediately after birth. PO data (oxygen saturation, HR and signal quality) were downloaded every 2 sec and analysed only when the signal had no alarm messages (low IQ signal, low perfusion, sensor off, ambient light). Results Data from 468 infants with 61 650 data points were included. Infants had a mean (range) gestational age of 38 (25-42) weeks and birth weight 2970 (625-5135) g. At 1 min the median (IQR) HR was 96 (65-127) beats per min (bpm) rising at 2 min and 5 min to 139 (110-166) bpm and 163 (146-175) bpm respectively. In preterm infants, the HR rose more slowly than term infants. Conclusions The median HR was <100 bpm at 1 min after birth. After 2 min it was uncommon to have a HR <100 bpm. In preterm infants and those born by caesarean section the HR rose more slowly than term vaginal births. PMID:20444810

  11. Heart rate variability as a biomarker of fibromyalgia syndrome

    PubMed Central

    Staud, Roland

    2009-01-01

    Fibromyalgia (FM) is a chronic pain syndrome characterized by widespread mechanical tenderness, fatigue, nonrefreshing sleep and depressed mood. Several biological abnormalities have been described in FM patients, including elevated substance P in the cerebrospinal fluid, increased CNS sensitivity to painful and nonpainful stimuli and pervasive dysfunction of the autonomic nervous system (ANS). Such ANS abnormalities include, but are not limited to: tachycardia, postural intolerance, Raynaud’s phenomenon, and diarrhea or constipation. Heart rate variability (HRV) analysis of FM patients can be used to assess ANS dysfunction, specifically related to sympathovagal balance, which has provided evidence for nonabating sympathetic hyperactivity in this chronic pain population. Although not specific for FM, ANS dysfunction can be readily determined by HRV analysis requiring only computer analysis of electrocardiogram recordings by commercially available software. HRV has been shown to correlate with FM pain and is sensitive to change; in particular, pain related to physical and mental stressors. Thus, ANS dysfunction as assessed by HRV analysis may serve as a useful biomarker, and may become part of future FM diagnostic criteria and serve as a surrogate end point in clinical trials. PMID:19890437

  12. Heart rate variability in patients with untreated Parkinson's disease.

    PubMed

    Kallio, M; Haapaniemi, T; Turkka, J; Suominen, K; Tolonen, U; Sotaniemi, K; Heikkilä, V P; Myllylä, V

    2000-11-01

    The aim of this study was to evaluate cardiovascular responses as a marker of autonomic nervous system (ANS) disturbances in patients with untreated Parkinson's disease (PD) and to assess the relationship between them and the clinical characteristics of PD. The ANS functions were investigated in 50 patients with PD and 55 healthy subjects by measuring standard cardiovascular autonomic reflexes and heart rate variability (HRV) at rest using spectral analysis (the autoregressive model and the fast Fourier transformation), the percentage of the counts of beat-to-beat variation greater than 50 ms and the fractal dimension. Significantly attenuated HRV and deficient blood pressure reaction to tilting were found in the PD patient group. The patients with hypokinesia/rigidity as the initial symptom of PD had a more pronounced HRV deficit than those with tremor onset. Untreated PD patients suffer significant failure in cardiovascular nervous system regulation, and in patients with hypokinesia/rigidity as their initial disease manifestation the risk of this ANS dysfunction is high. However, in the early stages of PD these changes did not reach significance at individual level. PMID:11136353

  13. Nicotine Acutely Inhibits Erectile Tumescence by Altering Heart Rate Variability

    PubMed Central

    Harte, Christopher B.

    2014-01-01

    Objective To examine potential mechanisms underlying nicotine’s effects on male sexual arousal by exploring the mediating role of heart rate variability (HRV). Methods The sample comprised 22 healthy, nicotine-naïve men (Mage = 20.91 years; SD = 2.43). Data were taken from a double-blind, randomized, placebo-controlled, crossover trial previously completed and published elsewhere. During each laboratory visit, time-domain parameters of HRV (standard deviation of normal-to-normal [NN] intervals [SDNN], square root of the mean squared difference of successive NN intervals [RMSSD], percent of NN intervals for which successive heartbeat intervals differed by at least 50 ms [pNN50]) were assessed, as well as objective (via penile plethysmography) and subjective indices of sexual arousal. Results Acute nicotine ingestion (compared to placebo) was associated with dysregulated sympathovagal balance, which in turn was related to relatively reduced erectile tumescence. HRV did not mediate relations between nicotine intake and self-reported indices of sexual arousal. Conclusions HRV mediated the association between nicotine ingestion and erectile capacity. Findings suggest that dysfunctional cardiac autonomic tone may be an underlying mechanism by which nicotine exerts its deleterious effects on erectile health. PMID:24642073

  14. Heart rate variability: a tool to explore the sleeping brain?

    PubMed Central

    Chouchou, Florian; Desseilles, Martin

    2014-01-01

    Sleep is divided into two main sleep stages: (1) non-rapid eye movement sleep (non-REMS), characterized among others by reduced global brain activity; and (2) rapid eye movement sleep (REMS), characterized by global brain activity similar to that of wakefulness. Results of heart rate variability (HRV) analysis, which is widely used to explore autonomic modulation, have revealed higher parasympathetic tone during normal non-REMS and a shift toward sympathetic predominance during normal REMS. Moreover, HRV analysis combined with brain imaging has identified close connectivity between autonomic cardiac modulation and activity in brain areas such as the amygdala and insular cortex during REMS, but no connectivity between brain and cardiac activity during non-REMS. There is also some evidence for an association between HRV and dream intensity and emotionality. Following some technical considerations, this review addresses how brain activity during sleep contributes to changes in autonomic cardiac activity, organized into three parts: (1) the knowledge on autonomic cardiac control, (2) differences in brain and autonomic activity between non-REMS and REMS, and (3) the potential of HRV analysis to explore the sleeping brain, and the implications for psychiatric disorders. PMID:25565936

  15. Suppressed circadian heart rate dynamics in temporal lobe epilepsy

    PubMed Central

    Ronkainen, E; Ansakorpi, H; Huikuri, H; Myllyla, V; Isojarvi, J; Korpelainen, J

    2005-01-01

    Objectives: To measure interictal circadian rhythm of heart rate (HR) variability in patients with temporal lobe epilepsy (TLE) using a 24 hour ECG recording. Methods: Various conventional and dynamic fractal measures of HR variability were analysed in 17 patients with refractory TLE, 20 patients with well controlled TLE, and 37 healthy age and sex matched control subjects. Results: The SD of all RR intervals (p<0.01), the measured power spectral components of HR variability (low frequency power (p<0.01), high frequency power (p<0.05)), and the SD1 (p<0.05) and SD2 (p<0.01) Poincaré two dimensional vector analysis measurements were suppressed in the patients. This suppression was observed during both day and night time; however, it was more pronounced at night, and nocturnal increase in HR variability usually seen in the normal population could not be detected in the patients. The HR variability measures did not correlate with the duration of epilepsy, the age of the patients, or with the anti-epileptic drugs used. Conclusion: TLE was associated with reduced HR variability, which was more pronounced during night than day, and the nocturnal increase in HR variability was abolished in patients with TLE. The alteration in autonomic regulation of HR variability was similar in patients with both refractory and well controlled TLE. PMID:16170081

  16. Non-contact estimation of heart rate and oxygen saturation using ambient light

    PubMed Central

    Bal, Ufuk

    2014-01-01

    We propose a robust method for automated computation of heart rate (HR) from digital color video recordings of the human face. In order to extract photoplethysmographic signals, two orthogonal vectors of RGB color space are used. We used a dual tree complex wavelet transform based denoising algorithm to reduce artifacts (e.g. artificial lighting, movement, etc.). Most of the previous work on skin color based HR estimation performed experiments with healthy volunteers and focused to solve motion artifacts. In addition to healthy volunteers we performed experiments with child patients in pediatric intensive care units. In order to investigate the possible factors that affect the non-contact HR monitoring in a clinical environment, we studied the relation between hemoglobin levels and HR estimation errors. Low hemoglobin causes underestimation of HR. Nevertheless, we conclude that our method can provide acceptable accuracy to estimate mean HR of patients in a clinical environment, where the measurements can be performed remotely. In addition to mean heart rate estimation, we performed experiments to estimate oxygen saturation. We observed strong correlations between our SpO2 estimations and the commercial oximeter readings PMID:25657877

  17. Reducing sojourn points from recurrence plots to improve transition detection: Application to fetal heart rate transitions.

    PubMed

    Zaylaa, Amira; Charara, Jamal; Girault, Jean-Marc

    2015-08-01

    The analysis of biomedical signals demonstrating complexity through recurrence plots is challenging. Quantification of recurrences is often biased by sojourn points that hide dynamic transitions. To overcome this problem, time series have previously been embedded at high dimensions. However, no one has quantified the elimination of sojourn points and rate of detection, nor the enhancement of transition detection has been investigated. This paper reports our on-going efforts to improve the detection of dynamic transitions from logistic maps and fetal hearts by reducing sojourn points. Three signal-based recurrence plots were developed, i.e. embedded with specific settings, derivative-based and m-time pattern. Determinism, cross-determinism and percentage of reduced sojourn points were computed to detect transitions. For logistic maps, an increase of 50% and 34.3% in sensitivity of detection over alternatives was achieved by m-time pattern and embedded recurrence plots with specific settings, respectively, and with a 100% specificity. For fetal heart rates, embedded recurrence plots with specific settings provided the best performance, followed by derivative-based recurrence plot, then unembedded recurrence plot using the determinism parameter. The relative errors between healthy and distressed fetuses were 153%, 95% and 91%. More than 50% of sojourn points were eliminated, allowing better detection of heart transitions triggered by gaseous exchange factors. This could be significant in improving the diagnosis of fetal state. PMID:25308517

  18. Effect of angiotensin II on baroreceptor reflex control of heart rate in conscious baboons.

    PubMed

    Garner, M G; Phippard, A F; Fletcher, P J; Maclean, J M; Duggin, G G; Horvath, J S; Tiller, D J

    1987-12-01

    Studies of the baroreceptor-heart rate reflex were performed in four conscious, unrestrained male baboons to determine whether changes in circulating angiotensin II within the physiological range are associated with alterations in baroreceptor reflex sensitivity. With the animals on a high sodium intake, studies were performed before and during graded angiotensin II infusion (10 and 20 ng/kg/min). To separate effects on baroreceptor reflex function mediated by angiotensin II-induced increases in arterial pressure, these studies were repeated on a different day with simultaneous glyceryl trinitrate infusion to prevent increases in pressure during angiotensin II infusion. With the animals on a low sodium intake, studies were performed before and after angiotensin converting enzyme inhibition with captopril (1 and 5 mg/kg). These studies were also repeated on a separate day during simultaneous phenylephrine infusion to prevent a decrease in pressure with captopril. Reduction in sodium intake had no significant effect on arterial pressure, heart rate, or plasma volume, although arterial plasma angiotensin II concentration and renin activity were significantly increased (p less than 0.01). Infusion of angiotensin II produced a significant reduction in baroreceptor reflex sensitivity (p less than 0.01), and converting enzyme inhibition produced a significant increase (p less than 0.05). These effects accompanied significant increases and decreases in arterial angiotensin II concentration, respectively (p less than 0.01), but were independent of angiotensin II-related changes in arterial pressure. The data indicate that physiological variations in circulating angiotensin II have a direct effect on sensitivity of the baroreceptor-heart rate reflex. PMID:3121505

  19. Application of a fetal scalp electrode for continuous fetal heart rate monitoring during an ex utero intrapartum treatment

    Microsoft Academic Search

    Masatoki Kaneko; Shunichi Tokunaga; Motoi Mukai; Seirou Machigashira; Youhei Maki; Yuki Kodama; Hiroshi Sameshima; Tsuyomu Ikenoue

    2011-01-01

    Fetal monitoring is required to avoid hypoxic injury during ex utero intrapartum treatment (EXIT). We performed a tracheostomy under EXIT in a case of suspected airway obstruction caused by a cervical teratoma. The scalp electrode was applied for continuous fetal heart rate monitoring. This device enabled us to promptly deal with fetal bradycardia caused by cord compression. We describe here

  20. Caffeine Consumption and Heart Rate and Blood Pressure Response to Regadenoson

    PubMed Central

    Bitar, Abbas; Mastouri, Ronald; Kreutz, Rolf P.

    2015-01-01

    Background Current guidelines recommend that caffeinated products should be avoided for at least 12 hours prior to regadenoson administration. We intended to examine the effect of caffeine consumption and of timing of last dose on hemodynamic effects after regadenoson administration for cardiac stress testing. Methods 332 subjects undergoing regadenoson stress testing were enrolled. Baseline characteristics, habits of coffee/caffeine exposure, baseline vital signs and change in heart rate, blood pressure, percent of maximal predicted heart rate, and percent change in heart rate were prospectively collected. Results Non-coffee drinkers (group 1) (73 subjects) and subjects who last drank coffee >24 hours (group 3) (139 subjects) prior to regadenoson did not demonstrate any difference in systolic blood pressure, heart rate change, maximal predicted heart rate and percent change in heart rate. Systolic blood pressure change (15.2±17.1 vs. 7.2±10.2 mmHg, p = 0.001), heart rate change (32.2±14 vs. 27.3±9.6 bpm, p = 0.038) and maximal predicted heart rate (65.5±15.6 vs. 60.7±8.6%, p = 0.038) were significantly higher in non-coffee drinkers (group 1) compared to those who drank coffee 12–24 hours prior (group 2) (108 subjects). Subjects who drank coffee >24 hours prior (group 3) exhibited higher systolic blood pressure change (13±15.8 vs. 7±10.2, p = 0.007), and heart rate change (32.1±15.3 vs. 27.3±9.6, p = 0.017) as compared to those who drank coffee 12–24 hours prior to testing (group 2). Conclusions Caffeine exposure 12–24 hours prior to regadenoson administration attenuates the vasoactive effects of regadenoson, as evidenced by a blunted rise in heart rate and systolic blood pressure. These results suggest that caffeine exposure within 24 hours may reduce the effects of regadenoson administered for vasodilatory cardiac stress testing. PMID:26098883

  1. The effect of a tailored message intervention on heart failure readmission rates, quality of life, and benefit and barrier beliefs in persons with heart failure

    Microsoft Academic Search

    Kristen A Sethares; Kathleen Elliott

    2004-01-01

    ObjectiveThe purpose of this study was to determine the effect of a tailored message intervention on heart failure readmission rates, quality of life, and health beliefs in persons with heart failure (HF).

  2. Effectiveness of self-management interventions on mortality, hospital readmissions, chronic heart failure hospitalization rate and quality of life in patients with chronic heart failure: A systematic review

    Microsoft Academic Search

    Joanne B. Ditewig; Helene Blok; Jeroen Havers; Haske van Veenendaal

    2010-01-01

    ObjectiveThis review examined the effectiveness of self-management interventions compared to usual care on mortality, all-cause hospital readmissions, chronic heart failure hospitalization rate and quality of life in patients with chronic heart failure.

  3. Relationship between obesity, negative affect and basal heart rate in predicting heart rate reactivity to psychological stress among adolescents.

    PubMed

    Park, Andres E; Huynh, Pauline; Schell, Anne M; Baker, Laura A

    2015-08-01

    Reduced cardiovascular responses to psychological stressors have been found to be associated with both obesity and negative affect in adults, but have been less well studied in children and adolescent populations. These findings have most often been interpreted as reflecting reduced sympathetic nervous system response, perhaps associated with heightened baseline sympathetic activation among the obese and those manifesting negative affect. However, obesity and negative affect may themselves be correlated, raising the question of whether they both independently affect cardiovascular reactivity. The present study thus examined the separate effects of obesity and negative affect on both cardiovascular and skin conductance responses to stress (e.g., during a serial subtraction math task) in adolescents, while controlling for baseline levels of autonomic activity during rest. Both obesity and negative affect had independent and negative associations with cardiovascular reactivity, such that reduced stress responses were apparent for obese adolescents and those with high levels of negative affect. In contrast, neither obesity nor negative affect was related to skin conductance responses to stress, implicating specifically noradrenergic mechanisms rather than sympathetic mechanisms generally as being deficient. Moreover, baseline heart rate was unrelated to obesity in this sample, which suggests that heightened baseline of sympathetic activity is not necessary for the reduced cardiovascular reactivity to stress. PMID:26049136

  4. Heart rate variability and circulating catecholamine concentrations during steady state exercise in healthy volunteers.

    PubMed Central

    Breuer, H W; Skyschally, A; Schulz, R; Martin, C; Wehr, M; Heusch, G

    1993-01-01

    OBJECTIVES--To assess whether exercise induced suppression of heart rate variability in the low frequency domain (0.06-0.15 Hz) is related to the increase in circulating catecholamine concentrations. DESIGN--Randomised crossover trial of three exercise tests characterised by different workloads. Pharmacological simulation of exercise-induced changes in vagal and sympathetic activity. PARTICIPANTS--Six healthy men with a mean age of 31.2 (SD 3.0) years. INTERVENTIONS--Three different workloads of steady state cycling ergometry: control state without cycling, cycling at a target heart rate of 100 beats/min, and cycling at a target heart rate of 150 beats/min. Intravenous infusion of atropine (target heart rate 100 beats/min) followed by the additional infusion of adrenaline and noradrenaline. MAIN OUTCOME MEASURES--Fast Fourier analysis of heart rate variability; blood pressure; and venous plasma concentrations of lactate, adrenaline, and noradrenaline. RESULTS--During the control exercise period there were no changes in the assessed variables compared with the preceding resting period. During exercise at a heart rate of 100 beats/min systolic blood pressure increased and heart rate variability decreased. During exercise at a heart rate of 150 beats/min systolic blood pressure and lactate, adrenaline, and noradrenaline concentrations increased. In addition, low frequency (LF) was lower than during exercise at 100 beats/min, high frequency (HF 0.15-0.80 Hz) resembled that during exercise at 100 beats/min, and diastolic blood pressure was reduced. Infusion of atropine caused no changes in blood pressure or plasma concentrations of lactate, adrenaline, and noradrenaline and decreased heart rate variability. The additional infusion of adrenaline and noradrenaline completely suppressed heart rate variability and increased blood pressure. CONCLUSIONS--The reduction in LF and HF during exercise at a heart rate of 100 beats/min, which is not characterised by increased plasma catecholamine concentrations, and during atropine infusion suggests that heart rate variability in the supine state is largely influenced by vagal activity. The additional reduction in LF during exercise at 150 beats/min and during catecholamine infusion may reflect a negative feedback of circulating catecholamines on the sympathetic control of heart rate. PMID:8038025

  5. Thick Filament Proteins and Performance in Human Heart Failure

    Microsoft Academic Search

    Bradley M. Palmer

    2005-01-01

    Modifications in thick filament protein content and performance are thought to underlie contraction-relaxation dysfunction\\u000a in human heart failure. It has been found that myofibrillar Mg.ATPase is reduced in failing myocardium, which may be due in\\u000a part to the reduction in ?-myosin heavy chain (MHC) isoform content from ?5–10% in normal myocardium to <2% in failing myocardium.\\u000a The physiological importance of

  6. Evaluation of heart rate changes: electrocardiographic versus photoplethysmographic methods

    NASA Technical Reports Server (NTRS)

    Low, P. A.; Opfer-Gehrking, T. L.; Zimmerman, I. R.; O'Brien, P. C.

    1997-01-01

    The heart rate (HR) variation to forced deep breathing (HRDB) and to the Valsalva maneuver (Valsalva ratio; VR) are the two most widely used tests of cardiovagal function in human subjects. The HR is derived from a continuously running electrocardiographic (ECG) recording. Recently, HR derived from the arterial waveform became available on the Finapres device (FinapHR), but its ability to detect rapid changes in HR remains uncertain. We therefore evaluated HRDB and VR derived from FinapHR using ECG-derived HR (ECGHR) recordings as the standard. We also compared the averaged HR on Finapres (Finapav) with beat-to-beat Finapres (FinapBB) values. Studies were undertaken in 12 subjects with large HR variations: age, 34.5 +/- 9.3 (SD) years; six males and six females. FinapBB values were superimposable upon ECGHR for both HRDB and VR. In contrast, Finapav failed to follow ECGHR for HRDB and followed HRECG with a lag for the VR. To evaluate statistically how closely FinapHR approximated ECGHR, we undertook regression analysis, using mean values for each subject. To compare the two methods, we evaluated the significance of the difference between test and standard values. For HRDB, FinapBB reproducibly recorded HR (R2 = 0.998), and was significantly (p = 0.001) better than Finapav (R2 = 0.616; p < 0.001). For VR, HRBB generated a VR that was not significantly different from the correct values, while HRav generated a value that was slightly but consistently lower than the correct values (p < 0.001). We conclude that FinapHR reliably records HR variations in the beat-to-beat mode for cardiovascular HR tests.

  7. Heart rate variability in normal and pathological sleep.

    PubMed

    Tobaldini, Eleonora; Nobili, Lino; Strada, Silvia; Casali, Karina R; Braghiroli, Alberto; Montano, Nicola

    2013-01-01

    Sleep is a physiological process involving different biological systems, from molecular to organ level; its integrity is essential for maintaining health and homeostasis in human beings. Although in the past sleep has been considered a state of quiet, experimental and clinical evidences suggest a noteworthy activation of different biological systems during sleep. A key role is played by the autonomic nervous system (ANS), whose modulation regulates cardiovascular functions during sleep onset and different sleep stages. Therefore, an interest on the evaluation of autonomic cardiovascular control in health and disease is growing by means of linear and non-linear heart rate variability (HRV) analyses. The application of classical tools for ANS analysis, such as HRV during physiological sleep, showed that the rapid eye movement (REM) stage is characterized by a likely sympathetic predominance associated with a vagal withdrawal, while the opposite trend is observed during non-REM sleep. More recently, the use of non-linear tools, such as entropy-derived indices, have provided new insight on the cardiac autonomic regulation, revealing for instance changes in the cardiovascular complexity during REM sleep, supporting the hypothesis of a reduced capability of the cardiovascular system to deal with stress challenges. Interestingly, different HRV tools have been applied to characterize autonomic cardiac control in different pathological conditions, from neurological sleep disorders to sleep disordered breathing (SDB). In summary, linear and non-linear analysis of HRV are reliable approaches to assess changes of autonomic cardiac modulation during sleep both in health and diseases. The use of these tools could provide important information of clinical and prognostic relevance. PMID:24137133

  8. Biology of Myotis thysanodes and M. lucifugus (Chiroptera: Vespertilionidae)—III. Metabolism, heart rate, breathing rate, evaporative water loss and general energetics

    Microsoft Academic Search

    EUGENE H. STUDIER

    1976-01-01

    Oxygen consumption (OC), weight specific oxygen consumption (VO). heart rate (HR). breathing rate (RR) and evaporative water loss (EWL) differ in adult female Mrotis th.wrnodes and M. ~uc~~uficgus and are significantly related to thermoregulatory performance (regulating or conforming) and to reproductive condition but not to body composttion. spleen or adrenal weights or age class. 2. Multiple regression equation models of

  9. Opportunity for information search and the effect of false heart rate feedback.

    PubMed

    Barefoot, John C; Straub, Ronald B

    2005-01-01

    The role of information search in the attribution of physiological states was investigated by manipulating the subject's opportunity for information search following the presentation of false information about his heart-rate reactions to photographs of female nudes. Consistent with the self-persuasion hypothesis proposed by Valins, the rated attractiveness of the slides was not affected by the false heart-rate feedback for those subjects who were prevented from visually searching the slides. Those subjects who had ample opportunity to view the slides rated those slides accompanied by false information of a heart-rate change as more attractive than those slides which were not paired with a change in heart rate. PMID:17477208

  10. Minimal changes in heart rate of incubating American Oystercatchers (Haematopus palliatus) in response to human activity

    USGS Publications Warehouse

    Borneman, Tracy E.; Rose, Eli T.; Simons, Theodore R.

    2014-01-01

    An organism's heart rate is commonly used as an indicator of physiological stress due to environmental stimuli. We used heart rate to monitor the physiological response of American Oystercatchers (Haematopus palliatus) to human activity in their nesting environment. We placed artificial eggs with embedded microphones in 42 oystercatcher nests to record the heart rate of incubating oystercatchers continuously for up to 27 days. We used continuous video and audio recordings collected simultaneously at the nests to relate physiological response of birds (heart rate) to various types of human activity. We observed military and civilian aircraft, off-road vehicles, and pedestrians around nests. With the exception of high-speed, low-altitude military overflights, we found little evidence that oystercatcher heart rates were influenced by most types of human activity. The low-altitude flights were the only human activity to significantly increase average heart rates of incubating oystercatchers (12% above baseline). Although statistically significant, we do not consider the increase in heart rate during high-speed, low-altitude military overflights to be of biological significance. This noninvasive technique may be appropriate for other studies of stress in nesting birds.

  11. Heart rate as a sublethal indicator of thermal stress in juvenile freshwater mussels.

    PubMed

    Pandolfo, Tamara J; Cope, W Gregory; Arellano, Consuelo

    2009-11-01

    Freshwater mussels (Unionoida) are one of the most sensitive and rapidly declining faunal groups in the world. Rising water temperatures, caused by industrial discharges, land development, or climate change can further challenge threatened unionid communities. The direct relationship between heart rate and temperature in ectotherms enables the use of heart rate as an indicator of whole-animal thermal stress. The purpose of this study was to assess the utility of heart rate as an indicator of thermal stress in freshwater mussels. Seven species of juvenile mussels (Lampsilis siliquoidea, Potamilus alatus, Ligumia recta, Ellipsaria lineolata, Megalonaias nervosa, Alasmidonta varicosa, and Villosa delumbis) were evaluated in response to a range of experimental temperatures (20-36 degrees C) at three acclimation temperatures (17, 22, and 27 degrees C). Heart rate was measured by direct visual observation through transparent mussel shells. The average heart rate for all 7 species at 20 degrees C was 55bpm, with a range from 38bpm (L. recta) to 65bpm (P. alatus). L. recta and V. delumbis exhibited significant changes in heart rate with increasing temperature at each of the three acclimation temperatures. The use of heart rate appears to be a suitable indicator of thermal stress in some unionid mussels. PMID:19596075

  12. Effects of propranolol, phenoxybenzamine, atropine and reserpine on the heart rate of thyroxine-treated chickens

    E-print Network

    Beaty, Barry Lee

    1975-01-01

    ', rate. Failure to demonstrate a resting tachycardia between groups suggests that thyroxine at the level used has no effect on the sino- atrial node in this study. Since the actions of reserpine and propranolol have similar effects on heart rate... EFFECTS OF PROPRANOLOL, PHENOXYBENZAHINE, ATROPINE AND RESERPINE ON THE HEART RATE OF THYROXINE-TREATED CHICKENS A Thesis BARRY LEE BEATY Submitted to the Graduate College of Texas AAH University in partial fulfillment of the requirement...

  13. In search of the optimal measure for assessment of parasympathetic control of heart rate

    Microsoft Academic Search

    Stuart D. Katz

    2010-01-01

    Springer-Verlag 2010 Parasympathetic control of heart rate is mediated via acetylcholine-dependent muscarinic receptor signaling at the sinoatrial node. Stimulation of the muscarinic type 2-receptor slows sinoatrial rate through Gi-coupled activation of inward rectifying KAch channel activity and indirect adenyl cyclase-dependent inhibition of the hyperpolarization activated If current [11, 15]. Parasympathetic control of heart rate can be indirectly assessed in human

  14. Multi-scale characteristics of resampled fetal heart rate pattern provide novel fetal developmental indices.

    PubMed

    Hoyer, Dirk; Nowack, Samuel; Schneider, Uwe

    2011-01-01

    The increasing functional integrity of the organism during fetal maturation is connected with increasing complex internal coordination mediated by the autonomic nervous system. We hypothesize that time scales of complex and dynamic inter-dependencies over more than one heart beat interval reflect the increasing complex adjustments within the fetal organism during its prenatal development. We investigated multi-scale complexity and time irreversibility from equidistantly resampled heart rate time series of 73 fetal magnetocardiographic recordings over the third trimester. We found scale dependent changes in complexity and time irreversibility. The functions obtained from equidistantly resampled heart rate time series showed qualitatively similar curves compared to those obtained from heart beat intervals series previously reported. Time scales of fetal heart rate characteristics may provide novel information for the identification of developmental disorders in prenatal diagnosis. PMID:22254592

  15. Estimating oxygen consumption from heart rate using adaptive neuro-fuzzy inference system and analytical approaches.

    PubMed

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

    2014-11-01

    In new approaches based on adaptive neuro-fuzzy systems (ANFIS) and analytical method, heart rate (HR) measurements were used to estimate oxygen consumption (VO2). Thirty-five participants performed Meyer and Flenghi's step-test (eight of which performed regeneration release work), during which heart rate and oxygen consumption were measured. Two individualized models and a General ANFIS model that does not require individual calibration were developed. Results indicated the superior precision achieved with individualized ANFIS modelling (RMSE = 1.0 and 2.8 ml/kg min in laboratory and field, respectively). The analytical model outperformed the traditional linear calibration and Flex-HR methods with field data. The General ANFIS model's estimates of VO2 were not significantly different from actual field VO2 measurements (RMSE = 3.5 ml/kg min). With its ease of use and low implementation cost, the General ANFIS model shows potential to replace any of the traditional individualized methods for VO2 estimation from HR data collected in the field. PMID:24793823

  16. Exploratory multivariate analysis of the effect of fatty fish consumption and medicinal use on heart rate and heart rate variability data.

    PubMed

    Grung, Bjørn; Hansen, Anita L; Berg, Mari; Møen-Knudseth, Maria P; Olson, Gina; Thornton, David; Dahl, Lisbeth; Thayer, Julian F

    2015-01-01

    The overall aim of the present study was to explore the relationship between medicinal use and fatty fish consumption on heart rate variability (HRV) and heart rate (HR) in a group of forensic inpatients on a variety of medications. A total of 49 forensic inpatients, randomly assigned to a fish group (n = 27) or a control group (n = 22) were included in the present study. Before and by the end of the food intervention period HR and HRV were measured during an experimental test procedure. An additional aim of this paper is to show how multivariate data analysis can highlight differences and similarities between the groups, thus being a valuable addition to traditional statistical hypothesis testing. The results indicate that fish consumption may have a positive effect on both HR and HRV regardless of medication, but that the influence of medication is strong enough to mask the true effect of fish consumption. Without correcting for medication, the fish group and control group become indistinguishable (p = 0.0794, Cohen's d = 0.60). The effect of medication is demonstrated by establishing a multivariate regression model that estimates HR and HRV in a recovery phase based on HR and HRV data recorded during psychological tests. The model performance is excellent for HR data, but yields poor results for HRV when employed on participants undergoing the more severe medical treatments. This indicates that the HRV behavior of this group is very different from that of the participants on no or lower level of medication. When focusing on the participants on a constant medication regime, a substantial improvement in HRV and HR for the fish group compared to the control group is indicated by a principal component analysis and t-tests (p = 0.00029, Cohen's d = 2.72). In a group of psychiatric inpatients characterized by severe mental health problems consuming different kinds of medication, the fish diet improved HR and HRV, indices of both emotional regulation and physical health. PMID:25741303

  17. Voluntary control of breathing does not alter vagal modulation of heart rate

    NASA Technical Reports Server (NTRS)

    Patwardhan, A. R.; Evans, J. M.; Bruce, E. N.; Eckberg, D. L.; Knapp, C. F.

    1995-01-01

    Variations in respiratory pattern influence the heart rate spectrum. It has been suggested, hence, that metronomic respiration should be used to correctly assess vagal modulation of heart rate by using spectral analysis. On the other hand, breathing to a metronome has been reported to increase heart rate spectral power in the high- or respiratory frequency region; this finding has led to the suggestion that metronomic respiration enhances vagal tone or alters vagal modulation of heart rate. To investigate whether metronomic breathing complicates the interpretation of heart rate spectra by altering vagal modulation, we recorded the electrocardiogram and respiration from eight volunteers during three breathing trials of 10 min each: 1) spontaneous breathing (mean rate of 14.4 breaths/min); 2) breathing to a metronome at the rate of 15, 18, and 21 breaths/min for 2, 6, and 2 min, respectively; and 3) breathing to a metronome at the rate of 18 breaths/min for 10 min. Data were also collected from eight volunteers who breathed spontaneously for 20 min and breathed metronomically at each subject's mean spontaneous breathing frequency for 20 min. Results from the three 10-min breathing trials showed that heart rate power in the respiratory frequency region was smaller during metronomic breathing than during spontaneous breathing. This decrease could be explained fully by the higher breathing frequencies used during trials 2 and 3 of metronomic breathing. When the subjects breathed metronomically at each subject's mean breathing frequency, the heart rate powers during metronomic breathing were similar to those during spontaneous breathing. Our results suggest that vagal modulation of heart rate is not altered and vagal tone is not enhanced during metronomic breathing.

  18. Detection and screening of sleep apnea using spectral and time domain analysis of heart rate variability

    Microsoft Academic Search

    Abed Elhamid Lawabni; Ahmed H. Tewfik

    2003-01-01

    Sleep apnea syndrome (SAS) is one of the most common breathing related sleep disorders. Sleep apnea (SA) may be of particular concern in chronic heart failure patients due to its high levels of cardiovascular morbidity and mortality. Our aim was to assess the diagnostic potential of SA using spectral analysis of nocturnal heart rate, and to introduce new simple time

  19. Activity in the human brain predicting differential heart rate responses to emotional facial expressions

    Microsoft Academic Search

    Hugo D. Critchley; Pia Rotshtein; Yoko Nagai; John O'Doherty; Christopher J. Mathias; Raymond J. Dolan

    2005-01-01

    The James-Lange theory of emotion proposes that automatically generated bodily reactions not only color subjective emotional experience of stimuli, but also necessitate a mechanism by which these bodily reactions are differentially generated to reflect stimulus quality. To examine this putative mechanism, we simultaneously measured brain activity and heart rate to identify regions where neural activity predicted the magnitude of heart

  20. Understanding autonomic sympathovagal balance from short-term heart rate variations. Are we analyzing noise?

    Microsoft Academic Search

    Jordi Altimiras

    1999-01-01

    Heart rate variations reflect the output of the complex control of the heart mediated by the autonomic nervous system. Because of that, they also encode different types of information, namely the efferent outflow of reflex mechanisms involved in the beat-to-beat control of cardiac function, the efferent activity of neurohumoral elements involved in the control of other cardiovascular parameters and random

  1. Comparison of Doppler ultrasound and direct electrocardiography acquisition techniques for quantification of fetal heart rate variability

    Microsoft Academic Search

    Janusz Jezewski; Janusz Wrobel; Krzysztof Horoba

    2006-01-01

    A method for comparison of two acquisition techniques that are applied in clinical practice to provide information on fetal condition is presented. The aim of this work was to evaluate the commonly used Doppler ultrasound technique for monitoring of mechanical activity of fetal heart. Accuracy of beat-to-beat interval determination together with its influence on indices describing the fetal heart rate

  2. TELEMENTRY OF HEART RATES IN LARGE RAPTORS: A METHOD OF TRANSMITTER AND ELECTRODE PLACEMENT

    Microsoft Academic Search

    KEVIN T. PATTON; WALTER C. CRAWFORD; WILLIAM SAWYER

    Heart rates of the Red-tailed Hawk (Buteo jamaicensis) and Barred Owl (Strix varia) were monitored telemetrically. The most acceptable data were received from devices whose electrodes were anchored within the thoracoabdominal space near the apex of the heart (primary lead) and dotsum (reference lead). Easily assembled plastic backpacks and leather harnesses were designed to be comfortable to birds and also

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

    Microsoft Academic Search

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

    1991-01-01

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

  4. Embryos in the Fast Lane: High-Temperature Heart Rates of Turtles Decline After Hatching

    PubMed Central

    Du, Wei-Guo; Zhao, Bo; Shine, Richard

    2010-01-01

    In ectotherms such as turtles, the relationship between cardiovascular function and temperature may be subject to different selective pressures in different life-history stages. Because embryos benefit by developing as rapidly as possible, and can “afford” to expend energy to do so (because they have access to the yolk for nutrition), they benefit from rapid heart (and thus, developmental) rates. In contrast, hatchlings do not have a guaranteed food supply, and maximal growth rates may not enhance fitness—and so, we might expect a lower heart rate, especially at high temperatures where metabolic costs are greatest. Our data on two species of emydid turtles, Chrysemys picta, and Graptemys pseudogeographica kohnii, support these predictions. Heart rates of embryos and hatchlings were similar at low temperatures, but heart rates at higher temperatures were much greater before than after hatching. PMID:20224773

  5. Embryos in the fast lane: high-temperature heart rates of turtles decline after hatching.

    PubMed

    Du, Wei-Guo; Zhao, Bo; Shine, Richard

    2010-01-01

    In ectotherms such as turtles, the relationship between cardiovascular function and temperature may be subject to different selective pressures in different life-history stages. Because embryos benefit by developing as rapidly as possible, and can "afford" to expend energy to do so (because they have access to the yolk for nutrition), they benefit from rapid heart (and thus, developmental) rates. In contrast, hatchlings do not have a guaranteed food supply, and maximal growth rates may not enhance fitness--and so, we might expect a lower heart rate, especially at high temperatures where metabolic costs are greatest. Our data on two species of emydid turtles, Chrysemys picta, and Graptemys pseudogeographica kohnii, support these predictions. Heart rates of embryos and hatchlings were similar at low temperatures, but heart rates at higher temperatures were much greater before than after hatching. PMID:20224773

  6. The Role of ?7 Nicotinic Acetylcholine Receptor in Modulation of Heart Rate Dynamics in Endotoxemic Rats

    PubMed Central

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

    2013-01-01

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

  7. Influence of exercise modality on agreement between gas exchange and heart rate variability thresholds

    PubMed Central

    Cunha, F.A.; Montenegro, R.A.; Midgley, A.W.; Vasconcellos, F.; Soares, P.P.; Farinatti, P.

    2014-01-01

    The main purpose of this study was to investigate the level of agreement between the gas exchange threshold (GET) and heart rate variability threshold (HRVT) during maximal cardiopulmonary exercise testing (CPET) using three different exercise modalities. A further aim was to establish whether there was a 1:1 relationship between the percentage heart rate reserve (%HRR) and percentage oxygen uptake reserve (%V?O2?R) at intensities corresponding to GET and HRVT. Sixteen apparently healthy men 17 to 28 years of age performed three maximal CPETs (cycling, walking, and running). Mean heart rate and V?O2 at GET and HRVT were 16 bpm (P<0.001) and 5.2 mL·kg-1·min-1 (P=0.001) higher in running than cycling, but no significant differences were observed between running and walking, or cycling and walking (P>0.05). There was a strong relationship between GET and HRVT, with R2 ranging from 0.69 to 0.90. A 1:1 relationship between %HRR and %V?O2?R was not observed at GET and HRVT. The %HRR was higher during cycling (GET mean difference=7%; HRVT mean difference=11%; both P<0.001), walking (GET mean difference=13%; HRVT mean difference=13%; both P<0.001), or running (GET mean difference=11%; HRVT mean difference=10%; both P<0.001). Therefore, using HRVT to prescribe aerobic exercise intensity appears to be valid. However, to assume a 1:1 relationship between %HRR and %V?O2?R at HRVT would probably result in overestimation of the energy expenditure during the bout of exercise. PMID:25003546

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

    PubMed Central

    Toufan, Mehrnoush; Kazemi, Babak; Akbarzadeh, Fariborz; Ataei, Amin; Khalili, Majid

    2012-01-01

    Background: Over the last two decades, morphological cardiac changes induced by athletic conditioning have been of great interest. Therefore, several studies have been orchestrated to delineate electrocardiography (ECG), echocardiography, and heart rate variability (HRV) findings in athletes. Purpose: To assess the ECG, echocardiography, and HRV in a group of dynamic and static type athletes. Methods: Fifty professional athletes (20 static and 30 dynamic exercise athletes) and 50 healthy nonathletes (control group) were recruited. Standard 12-lead ECG and transthoracic echocardiography was performed on all athletes and the control group. Through echocardiography, variables including left ventricular (LV) end-diastolic/systolic diameter, LV mass, and left atrial volume index were measured. In addition, both the athletes and the control group underwent ECG Holter monitoring for 15 minutes and several parameters related to HRV (time and frequency domain) were recorded. Results: The most common ECG abnormalities among the athletes were sinus bradycardia and incomplete right bundle branch block. LV end-diastolic diameter and left atrial volume index were significantly greater in the dynamic athletes (P < 0.001). LV end-systolic diameter was significantly lower in the static group (P < 0.001). LV mass of the dynamic and static athletes was significantly greater than that of the controls (P < 0.001). Among the ECG Holter monitoring findings, the dynamic athletes had lower systolic blood pressure than the controls (P = 0.01). Heart rate was lowest in the control group (P < 0.001). Conclusion: The most common ECG abnormalities among adolescent Iranian athletes were sinus bradycardia and incomplete right bundle branch block. Static exercise seemed to reduce LV end-systolic diameter, while dynamic exercise resulted in increased LV end-diastolic diameter and left atrial volume index. Additionally, Iranian athletes showed no differences in HRV parameters, excluding heart rate and systolic blood pressure, compared with the nonathletes. PMID:22924010

  9. ROC Analysis and a Realistic Model of Heart Rate Variability

    E-print Network

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

    1998-06-19

    We have carried out a pilot study on a standard collection of electrocardiograms from patients who suffer from congestive heart failure, and subjects without cardiac pathology, using receiver-operating-characteristic (ROC) analysis. The scale-dependent wavelet-coefficient standard deviation \\sigma_{wav}(m), a multiresolution-based analysis measure, is found to be superior to two commonly used measures of cardiac dysfunction when the two classes of patients cannot be completely separated. A jittered integrate-and-fire model with a fractal Gaussian-noise kernel provides a realistic simulation of heartbeat sequences for both heart-failure patients and normal subjects.

  10. The diurnal rhythm in fetal heart rate in a twin pregnancy with discordant anencephaly: comparison with three normal twin pregnancies

    Microsoft Academic Search

    Simone Lunshof; Kees Boer; Gerdien van Hoffen; Hans Wolf; Majid Mirmiran

    1997-01-01

    In a discordant anencephalic twin the hypothesis was tested that the fetal brain is necessary for the expression of a diurnal rhythm in fetal heart rate. Fetal heart rate recordings were made over a 24 h period in a discordant anencephalic twin pregnancy and in three normal twin pregnancies. Cosinor analysis was used to assess rhythmicity in fetal heart rate

  11. An ontogenetic shift in the response of heart rates to temperature in the developing snapping turtle ( Chelydra serpentina)

    Microsoft Academic Search

    Geoffrey F Birchard

    2000-01-01

    The affect of acute changes in temperature on heart rates was investigated for the first time in a developing reptile. Heart rates were determined early and late in incubation in snapping turtle (Chelydra serpentina) eggs. Late in incubation heart rates at any given temperature were lower than those observed early in incubation. The results of temperature switching experiments late in

  12. Heart Rate Variability Biofeedback as a Method for Assessing Baroreflex Function: A Preliminary Study of Resonance in the Cardiovascular System

    Microsoft Academic Search

    Evgeny Vaschillo; Paul Lehrer; Naphtali Rishe; Mikhail Konstantinov

    2002-01-01

    This study describes the use of a biofeedback method for the noninvasive study of baroreflex mechanisms. Five previously untrained healthy male participants learned to control oscillations in heart rate using biofeedback training to modify their heart rate variability at specific frequencies. They were instructed to match computer-generated sinusoidal oscillations with oscillations in heart rate at seven frequencies within the range

  13. Periodic spectral components of fetal heart rate variability reflect the changes in cord arterial base deficit values: a preliminary report

    Microsoft Academic Search

    Tiina Rantonen; Eeva Ekholm; Saila Siira; Taina Metsälä; Riitta Leino; Ulla Ekblad; Ilkka Välimäki

    2001-01-01

    Fetal distress changes the function of the autonomic nervous system. These changes are reflected in the fetal heart rate and can be quantified with power spectrum analysis of heart rate variability. The purpose of this study was to find out whether spectral components of fetal heart rate variability (FHRV) during labor are associated with fetal cord arterial base deficit values

  14. Combined Effects of Depressive Symptoms and Resting Heart Rate on Mortality: The Whitehall II Prospective Cohort Study

    E-print Network

    Boyer, Edmond

    1 Combined Effects of Depressive Symptoms and Resting Heart Rate on Mortality: The Whitehall II Prospective Cohort Study Running title: Depression, Resting Heart Rate and Mortality Hermann Nabi, PhD1* Mika and resting heart rate (RHR) on mortality. Methods: Data come from 5936 participants, aged 61 ±6 years, from

  15. HRV measures for CHF detection Page nr. 1 of 8 Discrimination power of long-term heart rate variability

    E-print Network

    Oakley, Jeremy

    HRV measures for CHF detection Page nr. 1 of 8 1 Discrimination power of long-term heart rate: Melillo P, Fusco R, Sansone M, Bracale M, Pecchia L (2011) Discrimination power of long-term heart rate-010-0728-5 Abstract The aim of this study was to investigate the discrimination power of standard long-term Heart Rate

  16. Abstract--We report that combining the interbeat heart rate as measured by the RR interval (RR) and R-

    E-print Network

    Manry, Michael

    1 of 4 Abstract-- We report that combining the interbeat heart rate as measured by the RR interval were 99.0%, 96.7%, and 97.8%, respectively. Keywords-- ECG, Heart Rate Variability, R-Peak Envelope heart rate variability (HRV), R-wave attenuation, ECG-Derived Respiration (EDR) and power spectral

  17. ELSEVIER Physica A 215 (1995) 439-450 A model of neural control of the heart rate

    E-print Network

    Potsdam, Universität

    1995-01-01

    ELSEVIER Physica A 215 (1995) 439-450 A model of neural control of the heart rate Michael Rosenblum of heart rate regulation is proposed, using the assumption that the nervous system regulates the generation reproduces time series of RR intervals. Different known patterns of heart rate variability are observed

  18. INTELLIGENT FETAL HEART RATE ANALYSIS J F Skinner', J M Garibaldi', J Curnow3,E C Ifeachor'

    E-print Network

    Aickelin, Uwe

    14 INTELLIGENT FETAL HEART RATE ANALYSIS J F Skinner', J M Garibaldi', J Curnow3,E C Ifeachor The cardiotocogram(CTG) consists of a continuous recording of fetal heart rate and maternal contractions during labour. Changes in the fetal heart rate pattern relative to contractions provide an indication of fetal

  19. hal-00176298,version2-26Mar2008 A new stochastic process to model Heart Rate series

    E-print Network

    Paris-Sud XI, Université de

    hal-00176298,version2-26Mar2008 A new stochastic process to model Heart Rate series during; Hurst parameter; Long-range dependence processes; Heart rate time series 1. Introduction The content of relevant parameters charac- terizing these instantaneous heart rate signals of athletes recorded during

  20. Differences Between ECG and Pulse When Measuring Heart Rate and Reactivity Under Two Physical and Two Psychological Stressors

    Microsoft Academic Search

    Christopher F. Sharpley; Jocelynne E. Gordon

    1999-01-01

    To test the level of agreement of heart rate and reactivity to stressor tasks as measured via noninvasive ECG and pulse, 38 healthy subjects underwent four stressor tasks: mental arithmetic, reaction time, cold pressor, and bicycling. Data on resting and stressor heart rate were collected via ECG and photoplethysmography, and heart rate reactivity was calculated via five methods noted in

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

    NASA Astrophysics Data System (ADS)

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

    2012-04-01

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

  2. Vagal nerve activity and the high frequency peak of the heart rate variability.

    PubMed

    Yambe, T; Nanka, S; Kobayashi, S; Tanaka, A; Yoshizawa, M; Abe, K; Tabayashi, K; Takeda, H; Nitta, S

    1999-05-01

    For the Quality of life (QOL) of patients with an artificial heart system, monitoring an information of the cardiovascular control system may be important. We have been evaluating the autonomic nervous system for that purpose. Recently, fluctuations in hemodynamic parameters including heart rate variability (HRV) were evaluated by means of spectral analysis and nonlinear mathematical analysis. Respiratory wavers in HRV were thought to reflect ongoing information of the parasympathetic nerve activity. Is it true? In order to confirm this hypothesis, we recorded vagal nerve activity directly in the chronic animal experiments. Six healthy adult goats were anesthetized with Halothene inhalation and thoracotomy were performed by the fourth lib resection during mechanical ventilation. Arterial blood pressure, right and left atrial pressures were continuously monitored with the catheter insertion. Cardiac output was measured by the electromagnetic flowmeter attached to the ascending aorta. After the chest was closed, incision was made to the left neck and left vagal nerve was separated. Stainless steel electrodes were inserted into the vagal nerve and fixed by the plasticizer. After the incision was closed, the goats were transferred to the cage and extubated after waking. Hemodynamic parameters and vagal nerve activity were measured in the awake condition. The results showed that clear observation of the autonomic nerve discharges were embodied by this experimental system. The vagal nerve discharges were synchronized with heart beat and respiration. The vagal nerve tonus was significantly influenced by the hemodynamic alteration. However in some condition, the respiratory wave was not always consistent with tonus of the vagal nerve activity, thus suggesting that we should check another information to evaluate the parasympathetic tone. We must continue this study to evaluate an autonomic nerve during artificial heart circulation. PMID:10467931

  3. A non-contact method based on multiple signal classification algorithm to reduce the measurement time for accurately heart rate detection

    NASA Astrophysics Data System (ADS)

    Bechet, P.; Mitran, R.; Munteanu, M.

    2013-08-01

    Non-contact methods for the assessment of vital signs are of great interest for specialists due to the benefits obtained in both medical and special applications, such as those for surveillance, monitoring, and search and rescue. This paper investigates the possibility of implementing a digital processing algorithm based on the MUSIC (Multiple Signal Classification) parametric spectral estimation in order to reduce the observation time needed to accurately measure the heart rate. It demonstrates that, by proper dimensioning the signal subspace, the MUSIC algorithm can be optimized in order to accurately assess the heart rate during an 8-28 s time interval. The validation of the processing algorithm performance was achieved by minimizing the mean error of the heart rate after performing simultaneous comparative measurements on several subjects. In order to calculate the error the reference value of heart rate was measured using a classic measurement system through direct contact.

  4. Heart rate variability and metabolic rate in healthy young adults with low birth weight

    PubMed Central

    Weitz, Gunther; Bonnemeier, Hendrik; Süfke, Sven; Wellhöner, Peter; Lehnert, Hendrik; Dodt, Christoph

    2013-01-01

    Objective: Low birth weight (LBW) is associated with obesity and a higher cardiovascular risk in adult life. Since autonomic dysfunction could be a pathophysiological factor for this association, we assessed the impact of LBW on cardiac autonomic activity and metabolic rate in young adulthood. We hypothesized that the autonomic tone could be coupled with the metabolic rate in subjects with LBW. Methods: Heart rate variability (HRV) from 24-hour Holter-electrocardiograms was measured in 15 healthy adults aged 20 to 30 years with LBW (<2500g at term) and 15 paired subjects with normal birth weight (NBW). The pairs were closely matched by gender, age, and body mass index. Resting energy expenditure was measured by indirect calorimetry and body composition by bioimpedance. Results: Global HRV parameters were significantly higher in the LBW group and a marked difference was observed in the long wave fluctuations of the frequency domain (very low frequency). These fluctuations were positively correlated with the resting energy expenditure per body weight in the LBW and negatively in the NBW group. Only in the LBW group HRV was closely related to body fat. Interpretation: This case-control study indicates that autonomous nervous function is not generally deteriorated in young adults with LBW and has a significant association with metabolic rate. Thus, it may be a determinant of the body weight regulation in this group. The higher cardiovascular risk in ageing individuals with LBW would therefore rather be a consequence of weight gain than of a primary autonomous nervous dysfunction. PMID:24224135

  5. Modification of respiratory sinus arrhythmia by mean heart rate

    Microsoft Academic Search

    F. Gruneis; A. W. Frey; M. Dambacher; M. Adt

    1994-01-01

    Four different spectral methods for assessing the respiratory sinus arrhythmia (=RSA) are investigated: the spectrum of the tachogram, of the point process and of two subcases of the step-like interpolation algorithm. For a comparison the integral pulse frequency modulation model is applied. In the case that the mean heart interval is about 1 and breathing frequency is smaller than 0.1

  6. Cognitive effects of false heart-rate feedback

    Microsoft Academic Search

    Stuart Valins

    1966-01-01

    Explored some of the cognitive effects of internal events. The objective was to ascertain whether the labeling of emotional stimuli would be affected by information concerning internal reactions. Ss viewed 10 slides of seminude females while hearing sounds that were allegedly their heart beats. 1 group of Ss heard their \\

  7. Ambulatory blood pressure and heart rate during shuttle flight, entry and landing

    NASA Technical Reports Server (NTRS)

    Thornton, W.; Moore, T. P.; Uri, J.

    1993-01-01

    Ambulatory blood pressures (BP) and heart rates (HR) were recorded on a series of early Shuttle flights during preflight and pre-entry, entry, landing and egress. There were no significant differences between flight and preflight values during routine activity. Systolic blood pressure was slightly elevated in the deorbit period and systolic and diastolic blood pressure and heart rates were all elevated with onset of gravitoinertial loads and remained so through egress. Two of seven subjects had orthostatic problems in egress but their data did not show significant differences from others except in heart rate. Comparison of this data to that from recent studies show even larger increase in HR/BP values during current deorbit and entry phases which is consistent with increased heat and weight loads imposed by added survival gear. Both value and limitations of ambulatory heart rate/blood pressure data in this situation are demonstrated.

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

    EPA Science Inventory

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

  9. Development and validation of an improved smartphone heart rate acquisition system

    NASA Astrophysics Data System (ADS)

    Karapetyan, G.; Barseghyan, R.; Sarukhanyan, H.; Agaian, S.

    2015-03-01

    In this paper we propose a robust system for touchless heart rate (HR) acquisition on mobile devices. The application allows monitor heart rate signal during usual mobile device usage such as video watching, games playing, article reading etc. The system is based on algorithm of acquiring heart rate via recording of skin color variations with built-in cameras of mobile device. The signal is acquired from different ROIs of human face, which make it more clear and the amplification of the signal improve the robustness in low lightening conditions. The effectiveness and robustness of the developed system has been demonstrated under different distances from camera source and illumination conditions. The experiments have been done with different mobile devices HRs were collected from 10 subjects, ages 22 to 65, by using the 3 devices. Moreover, we compared the developed method with Food and Drug Administration (FDA) approved sensors and related commercial applications of remote heart rate measurements on mobile devices.

  10. Effects of propranolol, phenoxybenzamine, atropine and reserpine on the heart rate of thyroxine-treated chickens 

    E-print Network

    Beaty, Barry Lee

    1975-01-01

    to try to find the cause of this' Blockade of the sympathetic subdivision of the autonomic nervous system in man did not s:i. gnifi- cantly lower the heart rate during hyperthyroid1sm. Furthermore, blockade of the sympathetic and parasympathetic... properties. Since the para- sympathetic subdivision of the autonomio nervous system mediates the heart rate via the vagus nerve, a blockade of the postganglionic ' cholinergic fibers (the action of atropine) would relieve vagal ' , tone. A dose of 2. 5...

  11. Heart rate as an indicator of the intensity of physical activity in human adolescents

    Microsoft Academic Search

    Ulf Ekelund; Eric Poortvliet; Agneta Yngve; Anita Hurtig-Wennlöv; Andreas Nilsson; Michael Sjöström

    2001-01-01

    .   The aims of this study were, in a group of adolescents, firstly to identify the absolute heart rates (HR) and the percentages\\u000a of maximal heart rates (HRmax) corresponding to 40%, 60% and 80% of peak oxygen uptake (\\u000a ), secondly to identify absolute and relative (\\u000a ) oxygen uptakes (\\u000a ) corresponding to HR of 120, 140 and 160 beats·min–1,

  12. Heart Rate Response to Physical Therapy and Educational Activities in Children with Severe Mental Impairment

    Microsoft Academic Search

    Alice Yee-Men Jones; Mabel Mei-Po Wong

    2007-01-01

    This study investigated the change of heart rate during physical education (PE) or physical therapy sessions (PT) in students\\u000a with mental impairment (MI) and low physical activity. The heart rate (HR) of children with severe grade MI (IQ below 40)\\u000a attending a Special school was recorded continuously during two PE and two PT sessions in two consecutive weeks. Of the

  13. Blood pressure and heart rate during tonic immobility in the black tipped reef shark, Carcharhinus melanoptera

    Microsoft Academic Search

    Peter S. Davie; Craig E. Franklin; Gordon C. Grigg

    1993-01-01

    Tonic immobility was induced in black tipped reef sharks (Carcharhinus melanoptera) and heart rate and ventral aortic blood pressure recorded. Without branchial irrigation, tonic immobility was correlated\\u000a with a significant depression in blood pressure and heart rate irrespective of the sharks being in air or in water. Tonic\\u000a immobility with branchial irrigation resulted in a significant increase in blood pressure

  14. Heart rate—QT relationships during baroreceptor stimulation with diminished autonomic influence on the ventricles

    Microsoft Academic Search

    Ming-He Huang; Stephen S. Hull; Robert D. Foreman; Ralph Lazzara; Stewart Wolf

    1992-01-01

    The shortening of the QT interval of the electrocardiogram coincident with acceleration of heart rate and vice versa has been\\u000a accepted for many years as evidence that the action potential duration and hence QT are necessarily dependant on heart rate.\\u000a Exceptions to this rule have been attributed to the intervention of counteracting autonomic effects. In order to test this\\u000a assumption,

  15. Real-time monitoring of spontaneous resonance in heart rate variability

    Microsoft Academic Search

    Emil Jovanov

    2008-01-01

    The resonant characteristic of heart rate variability is usually generated using biofeedback and the external pacing of breathing, which is typically around 6 breaths\\/min (0.1 Hz), although the exact frequency varies between individuals. It was hypothesized that the actual resonant characteristic of heart rate actually depends on the current psychophysiological state of the subject; therefore, the real-team evaluation of this

  16. Heart Rate Variability and Particulate Exposure in Vehicle Maintenance Workers: A Pilot Study

    Microsoft Academic Search

    Robert M. Eninger; Frank S. Rosenthal

    2004-01-01

    The association between occupational exposure to PM2.5 and heart rate variability was investigated in a repeated measures, longitudinal study of vehicle maintenance workers occupationally exposed to automobile emissions. Five subjects were monitored for occupational exposure to fine particulate matter (PM2.5) on 6 workdays using an aerosol photometer, validated with side-by-side sampling with a gravimetric method. End-of-day heart rate variability statistics

  17. Gender differences and heritability of two indices of heart rate dynamics: A twin study

    Microsoft Academic Search

    Julian F. Thayer; Lorenz J. P. van Doornen; Dorret Boomsma; Harold Snieder

    2006-01-01

    e investigated whether women show larger heart rate variability (HRV) than men after controlling for a large number of health-related covari- ates, using two indices of HRV, namely respiratory sinus arrhythmia (RSA) and approximate entropy (ApEn). In a twin design, the heritability of both indices was examined. The covariation between RSA and ApEn, a measure of heart rate dynamics derived

  18. The effect of locus of control and learned helplessness on control of heart rate using biofeedback

    E-print Network

    Logsdon, Steven Alan

    1976-01-01

    EFFECTS WHEN SUBJECTS ARE ATTEMPTING TO DECREASE THEIR HEART RATE (C) Trials (A) Success (B) Increase first Increase second Failure Increase first Increase second Control Increase first Increase second NOTE: The same design is used for analysis... a primacy effect suggesting that those subjects who attempted to increase their heart rate first were able to increase significantly better than those who tried to increase it after first decreasing it. Within the failure condition in which...

  19. Effect of muscle mass and intensity of isometric contraction on heart rate

    Microsoft Academic Search

    JUAN P. ALONSO; LUIS A. SANGRADOR; GONZALO NAVARRO

    Galvez, JoseM., Juan P. Alonso, Luis A. Sangrador, and Gonzalo Navarro. Effect of muscle mass and intensity of isometric contraction on heart rate. J. Appl. Physiol. 88: 487-492, 2000.—The purpose of this study was to determine the effect of muscle mass and the level of force on the contraction-induced rise in heart rate. We conducted an experimental study in a

  20. Prediction of energy expenditure from heart rate monitoring during submaximal exercise

    Microsoft Academic Search

    LR Keytel; JH Goedecke; TD Noakes; H Hiiloskorpi; R Laukkanen; L van der Merwe; EV Lambert

    2005-01-01

    The aims of this study were to quantify the effects of factors such as mode of exercise, body composition and training on the relationship between heart rate and physical activity energy expenditure (measured in kJ?·?min) and to develop prediction equations for energy expenditure from heart rate. Regularly exercising individuals (n??=??115; age 18?–?45 years, body mass 47?–?120?kg) underwent a test for

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

    PubMed

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

    2015-05-01

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

  2. Validation of photoplethysmography as a method to detect heart rate during rest and exercise.

    PubMed

    Spierer, David K; Rosen, Zohn; Litman, Leib L; Fujii, Kenji

    2015-07-01

    Despite their enhanced marketplace visibility, validity of wearable photoplethysmographic heart rate monitoring is scarce. Forty-seven healthy participants performed seven, 6-min exercise bouts and completed a valid skin type scale. Participants wore an Omron HR500U (OHR) and a Mio Alpha (MA), two commercial wearable photoplethysmographic heart rate monitors. Data were compared to a Polar RS800CX (PRS). Means and error were calculated between devices using minutes 2-5. Compared to PRS, MA data was significantly different in walking, biking (2.41?±?3.99?bpm and 3.26?±?11.38?bpm, p?

  3. Effects of heart-rate feedback on estimated cardiovascular fitness in patients with panic disorder.

    PubMed

    Schmidt, N B; Lerew, D R; Santiago, H; Trakowski, J H; Staab, J P

    2000-01-01

    Psychological parameters that are believed to affect estimations of cardiovascular fitness were examined in patients with panic disorder and nonclinical controls. Fifty-four participants [panic disorder patients (n = 27) and age- and sex-matched nonclinical controls (n = 27)] completed a cycle ergometer test and were compared on the basis of estimated VO2 max. Participants were randomly assigned to experimental conditions in which they received heart-rate feedback or no feedback during the test. Patients with panic disorder exhibited lower VO2 max and decreased exercise tolerance (i.e., were more likely to discontinue the test) than nonclinical controls. Furthermore, individuals with high anxiety sensitivity (i.e., a fear of autonomic arousal), but not a panic disorder diagnosis per se, achieved significantly lower VO2 max when provided with heart-rate feedback. Moreover, diagnostic status interacted with levels of anxiety sensitivity to predict VO2 max. Patients with panic disorder display poorer cardiovascular fitness after controlling for anxiety and other factors that underestimate performance during fitness testing. PMID:11091928

  4. The effect of hypoxia and exercise on heart rate variability, immune response, and orthostatic stress.

    PubMed

    Koelwyn, G J; Wong, L E; Kennedy, M D; Eves, N D

    2013-02-01

    Hypoxia with exercise is commonly used to enhance physiological adaptation in athletes, but may prolong recovery between training bouts. To investigate this, heart rate variability (HRV), systemic immune response, and response to an orthostatic challenge were measured following exercise in hypoxia and air. Eleven trained men performed a 10-km cycling time trial breathing hypoxia (16.5 ± 0.5% O(2)) or air. HRV and the heart rate response to an orthostatic challenge were measured for 3 days before and after each trial, while venous blood samples were collected pre-, 0, 2, and 24 h post-exercise. Hypoxia had no significant effect compared with air. Subgroup analysis of those who had a drop in oxyhemoglobin saturation (SpO(2)) > 10% between hypoxia and air compared with those who did not, demonstrated a significantly altered HRV response (?HFnu: -2.1 ± 0.9 vs 8.6 ± 9.3, ?LFnu: 2.1 ± 1.0 vs -8.6 ± 9.4) at 24 h post-exercise and increased circulating monocytes (1.3 ± 0.2 vs 0.8 ± 0.2 × 10(9) /L) immediately post-hypoxic exercise. Exercise and hypoxia did not change HRV or the systemic immune response to exercise. However, those who had a greater desaturation during hypoxic exercise had an attenuate recovery 24 h post-exercise and may be more susceptible to accumulating fatigue with subsequent training bouts. PMID:23013143

  5. Second ventilatory threshold from heart-rate variability: valid when the upper body is involved?

    PubMed

    Mourot, Laurent; Fabre, Nicolas; Savoldelli, Aldo; Schena, Federico

    2014-07-01

    To determine the most accurate method based on spectral analysis of heart-rate variability (SA-HRV) during an incremental and continuous maximal test involving the upper body, the authors tested 4 different methods to obtain the heart rate (HR) at the second ventilatory threshold (VT(2)). Sixteen ski mountaineers (mean ± SD; age 25 ± 3 y, height 177 ± 8 cm, mass 69 ± 10 kg) performed a roller-ski test on a treadmill. Respiratory variables and HR were continuously recorded, and the 4 SA-HRV methods were compared with the gas-exchange method through Bland and Altman analyses. The best method was the one based on a time-varying spectral analysis with high frequency ranging from 0.15 Hz to a cutoff point relative to the individual's respiratory sinus arrhythmia. The HR values were significantly correlated (r(2) = .903), with a mean HR difference with the respiratory method of 0.1 ± 3.0 beats/min and low limits of agreements (around -6 /+6 beats/min). The 3 other methods led to larger errors and lower agreements (up to 5 beats/min and around -23/+20 beats/min). It is possible to accurately determine VT(2) with an HR monitor during an incremental test involving the upper body if the appropriate HRV method is used. PMID:24231307

  6. Poincare plot of heart rate variability: an approach towards explaining the cardiovascular autonomic function in obesity.

    PubMed

    Muralikrishnan, Krishnan; Balasubramanian, Kabali; Ali, Sajjadh M Jawahar; Rao, Badanidiyur Vishwanatha

    2013-01-01

    Obesity has been shown to affect cardiovascular function. Heart rate variability (HRV) has been an accepted method of measuring cardiovascular autonomic function. The aim of the study is to evaluate the impact of obesity on HRV using Poincaré plot (POP) analysis. A finding of sympathovagal imbalance in pre-obese adults in respiratory sinus arrhythmia (RSA) could provide important diagnostic information about early subclinical autonomic dysfunction in obesity. Thirty one obese (BMI 26.84 +/- 2.47) adult males (25.42 +/- 7.86 years) were compared with 31 normal subjects (25.38 +/- 4.61 years). In all participants, anthropometric and blood pressure (BP) measurements were performed. After rest at supine position for 5 minutes, they were asked to do control deep breathing for 1 minute. HRV was measured in terms of POP analysis. Differences in Resting heart rate (RHR) (P < or = 0.025), Pulse pressure (PP) (P < or = 0.048), SD1 (P < or = 0.042) and SD2 (P < or = 0.039) of the POP between the two groups were significant. Correlation between Body mass index (BMI) and (PP) (p = 0.19); SD1 (p = 0.47) and SD2 (p = 0.39) of the POP were significant in obese groups. Obesity is related to sympathovagal imbalance characterized by depressed parasympathetic tone and increased sympathetic activity. Nonlinear methods like POP permit simple assessment of autonomic function, despite measuring different aspects of HRV. PMID:24020096

  7. Heart rate variability during carbachol-induced REM sleep and cataplexy.

    PubMed

    Torterolo, Pablo; Castro-Zaballa, Santiago; Cavelli, Matías; Velasquez, Noelia; Brando, Victoria; Falconi, Atilio; Chase, Michael H; Migliaro, Eduardo R

    2015-09-15

    The nucleus pontis oralis (NPO) exerts an executive control over REM sleep. Cholinergic input to the NPO is critical for REM sleep generation. In the cat, a single microinjection of carbachol (a cholinergic agonist) into the NPO produces either REM sleep (REMc) or wakefulness with muscle atonia (cataplexy, CA). In order to study the central control of the heart rate variability (HRV) during sleep, we conducted polysomnographic and electrocardiogram recordings from chronically prepared cats during REMc, CA as well as during sleep and wakefulness. Subsequently, we performed statistical and spectral analyses of the HRV. The heart rate was greater during CA compared to REMc, NREM or REM sleep. Spectral analysis revealed that the low frequency band (LF) power was significantly higher during REM sleep in comparison to REMc and CA. Furthermore, we found that during CA there was a decrease in coupling between the RR intervals plot (tachogram) and respiratory activity. In contrast, compared to natural behavioral states, during REMc and CA there were no significant differences in the HRV based upon the standard deviation of normal RR intervals (SDNN) and the mean squared difference of successive intervals (rMSSD). In conclusion, there were differences in the HRV during naturally-occurring REM sleep compared to REMc. In addition, in spite of the same muscle atonia, the HRV was different during REMc and CA. Therefore, the neuronal network that controls the HRV during REM sleep can be dissociated from the one that generates the muscle atonia during this state. PMID:25997581

  8. Synchronization analysis between heart rate variability and EEG activity before, during, and after epileptic seizure.

    PubMed

    Piper, Diana; Schiecke, Karin; Leistritz, Lutz; Pester, Britta; Benninger, Franz; Feucht, Martha; Ungureanu, Mihaela; Strungaru, Rodica; Witte, Herbert

    2014-08-01

    Abstract An innovative concept for synchronization analysis between heart rate (HR) components and rhythms in EEG envelopes is represented; it applies time-variant analyses to heart rate variability (HRV) and EEG, and it was tested in children with temporal lobe epilepsy (TLE). After a removal of ocular and movement-related artifacts, EEG band activity was computed by means of the frequency-selective Hilbert transform providing envelopes of frequency bands. Synchronization between HRV and EEG envelopes was quantified by Morlet wavelet coherence. A surrogate data approach was adapted to test for statistical significance of time-variant coherences. Using this processing scheme, significant coherence values between a HRV low-frequency sub-band (0.08-0.12 Hz) and the EEG ? envelope (1.5-4 Hz) occurring both in the preictal and early postictal periods of a seizure can be shown. Investigations were performed for all electrodes at 20-s intervals and for selected electrode pairs (T3÷C3, T4÷C4) in a time-variant mode. Synchronization was more pronounced in the group of right hemispheric TLE patients than in the left hemispheric group. Such a group-specific augmentation of synchronization confirms the hypothesis of a right hemispheric lateralization of sympathetic cardiac control of the low-frequency HRV components. PMID:24695024

  9. The forgotten role of central volume in low frequency oscillations of heart rate variability.

    PubMed

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

    2015-01-01

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

  10. High-resolution motion-compensated imaging photoplethysmography for remote heart rate monitoring

    NASA Astrophysics Data System (ADS)

    Chung, Audrey; Wang, Xiao Yu; Amelard, Robert; Scharfenberger, Christian; Leong, Joanne; Kulinski, Jan; Wong, Alexander; Clausi, David A.

    2015-03-01

    We present a novel non-contact photoplethysmographic (PPG) imaging system based on high-resolution video recordings of ambient reflectance of human bodies that compensates for body motion and takes advantage of skin erythema fluctuations to improve measurement reliability for the purpose of remote heart rate monitoring. A single measurement location for recording the ambient reflectance is automatically identified on an individual, and the motion for the location is determined over time via measurement location tracking. Based on the determined motion information motion-compensated reflectance measurements at different wavelengths for the measurement location can be acquired, thus providing more reliable measurements for the same location on the human over time. The reflectance measurement is used to determine skin erythema fluctuations over time, resulting in the capture of a PPG signal with a high signal-to-noise ratio. To test the efficacy of the proposed system, a set of experiments involving human motion in a front-facing position were performed under natural ambient light. The experimental results demonstrated that skin erythema fluctuations can achieve noticeably improved average accuracy in heart rate measurement when compared to previously proposed non-contact PPG imaging systems.

  11. Public and private heart rate feedback in social phobia: a manipulation of anxiety visibility.

    PubMed

    Gerlach, Alexander L; Mourlane, Denis; Rist, Fred

    2004-01-01

    According to cognitive behavioural models of social phobia, bodily symptoms are the main source of information concerning social evaluation for social phobics. Experience and perception of bodily symptoms therefore play an important role in social anxiety. In this study we evaluated the effects of anxiety visibility on patients and controls using feedback of veridical heart sounds. A total of 32 social phobics and 32 controls were asked twice to sit in a chair and appear relaxed while being evaluated. Half of the participants heard their heart sounds first via headphones and then via loudspeakers which were also audible to observers. The presentation order of the heart sound was reversed for the other half of the subjects. Social phobics reported substantially more anxiety than controls. Both groups showed habituation in heart rate from the first to the second presentation, and both groups reported perception of a higher heart rate, but only social phobics reported significantly more anxiety and were more worried about their heart rates in the public than in the private condition. These effects were in excess of actual heart rate differences. In conclusion, social phobics worried about the broadcast of a bodily anxiety symptom, whereas controls did not. Information about arousal made public has a strong potential to increase anxiety levels in social phobics. PMID:15224627

  12. Effect of varying heart rate on intra-ventricular filling fluid dynamics

    NASA Astrophysics Data System (ADS)

    Santhanakrishnan, Arvind; Okafor, Ikechukwu; Angirish, Yagna; Yoganathan, Ajit

    2013-11-01

    Impaired exercise tolerance is used to delineate asymptomatic patients during the clinical diagnosis of diastolic left heart failure. Examining the effects of varying heart rate on intra-ventricular filling can provide a physical understanding of the specific flow characteristics that are impacted during exercise. In this study, diastolic filling was investigated with an anatomical left ventricle (LV) physical model under normal heart rate of 70 bpm, and varying exercise conditions of 100 bpm and 120 bpm. The LV model was incorporated into a flow loop and tuned for physiological inflow rates and outflow pressures. 2D PIV measurements were conducted along 3 parallel longitudinal planes. The systemic pressure was maintained the same across all test conditions. The E/A ratio was maintained within 1.0-1.2 across all heart rates. The strength of the mitral vortex ring formed during E-wave, as well as the peak incoming jet velocity, decreased with increasing heart rate. During peak flow of the A-wave, the vortex ring propagated farther into the LV for 120 bpm as compared to 70 bpm. The results point to the heightened role of the atrial kick for optimal LV filling during exercise conditions. Impaired exercise tolerance is used to delineate asymptomatic patients during the clinical diagnosis of diastolic left heart failure. Examining the effects of varying heart rate on intra-ventricular filling can provide a physical understanding of the specific flow characteristics that are impacted during exercise. In this study, diastolic filling was investigated with an anatomical left ventricle (LV) physical model under normal heart rate of 70 bpm, and varying exercise conditions of 100 bpm and 120 bpm. The LV model was incorporated into a flow loop and tuned for physiological inflow rates and outflow pressures. 2D PIV measurements were conducted along 3 parallel longitudinal planes. The systemic pressure was maintained the same across all test conditions. The E/A ratio was maintained within 1.0-1.2 across all heart rates. The strength of the mitral vortex ring formed during E-wave, as well as the peak incoming jet velocity, decreased with increasing heart rate. During peak flow of the A-wave, the vortex ring propagated farther into the LV for 120 bpm as compared to 70 bpm. The results point to the heightened role of the atrial kick for optimal LV filling during exercise conditions. This study was funded by a grant from the National Heart, Lung and Blood Institute (RO1HL70262).

  13. Heart rate detection in low amplitude non-invasive fetal ECG recordings.

    PubMed

    Peters, Chris; Vullings, Rik; Bergmans, Jan; Oei, Guid; Wijn, Pieter

    2006-01-01

    Multi-electrode electrical measurements on the maternal abdomen may provide a valuable alternative to standard fetal monitoring. Removal of the maternal ECG from these recordings by means of subtracting a weighted linear combination of segments from preceding maternal ECG complexes, results in fetal ECG traces from which the fetal heart rate can be determined. Unfortunately, these traces often contain too much noise to determine the heart rate by R-peak detection. To overcome this limitation, an algorithm has been developed that calculates the heart rate based on cross-correlation. To validate the algorithm, noise was added to a fetal scalp ECG recording to simulate low amplitude abdominal recordings. Heart rates calculated by the algorithm were compared to the heart rates from the original scalp ECG. For simulated signals with a signal to noise ratio of 2, the coefficient of correlation was 0.99 (p<0.001). By using the developed algorithm for calculating the fetal heart rate, multi-electrode electrical measurements on the maternal abdomen now can be used for fetal monitoring in relatively early stages of pregnancy or other situations where ECG amplitudes are low or noise levels are high. PMID:17946740

  14. Effects of aerobic training intensity on resting, exercise and post-exercise blood pressure, heart rate and heart-rate variability

    Microsoft Academic Search

    V A Cornelissen; B Verheyden; A E Aubert; R H Fagard

    2010-01-01

    We aimed to investigate the effects of endurance training intensity (1) on systolic blood pressure (SBP) and heart rate (HR) at rest before exercise, and during and after a maximal exercise test; and (2) on measures of HR variability at rest before exercise and during recovery from the exercise test, in at least 55-year-old healthy sedentary men and women. A

  15. Building trust: Heart rate synchrony and arousal during joint action increased by public goods game.

    PubMed

    Mitkidis, Panagiotis; McGraw, John J; Roepstorff, Andreas; Wallot, Sebastian

    2015-10-01

    The physiological processes underlying trust are subject of intense interest in the behavioral sciences. However, very little is known about how trust modulates the affective link between individuals. We show here that trust has an effect on heart rate arousal and synchrony, a result consistent with research on joint action and experimental economics. We engaged participants in a series of joint action tasks which, for one group of participants, was interleaved with a PGG, and measured their heart synchrony and arousal. We found that the introduction of the economic game shifted participants' attention to the dynamics of the interaction. This was followed by increased arousal and synchrony of heart rate profiles. Also, the degree of heart rate synchrony was predictive of participants' expectations regarding their partners in the economic game. We conclude that the above changes in physiology and behavior are shaped by the valuation of other people's social behavior, and ultimately indicate trust building process. PMID:26037635

  16. Short-term ECG recordings for heart rate assessment in patients with chronic atrial fibrillation

    PubMed Central

    Cygankiewicz, Iwona; Klimczak, Artur; Lewek, Joanna; Bartczak, Karol; Wranicz, Jerzy K.

    2014-01-01

    Introduction There is no consensus on the length of ECG tracing that should be recorded to represent adequate rate control in patients with atrial fibrillation (AFib). The purpose of the study was to examine whether heart rate measurements based on short-term ECGs recorded at different periods of the day may correspond to the mean heart rate and rate irregularity analyzed from standard 24-hour Holter monitoring. Material and methods The study enrolled 50 consecutive patients with chronic AFib who underwent 24-hour Holter monitoring. Mean heart rate (mHR) and the coefficient of irregularity (CI) were assessed from 5- and 60-minute intervals of Holter recordings in different periods of the day. Results The highest correlation in mean heart rate interval within 24 h was found during a 6-hour sample and in the periods 11.00 AM–12.00 PM, 12 PM–1.00 PM, and 1.00 PM–2.00 PM. With respect to irregularity, only the CI measurements based on a 6-hour interval (7.00 AM–1.00 AM) show a correlation > 0.08 compared to data from the 24-hour recording. Conclusions Only long-term (6-hour) recordings provide a high correlation within 24 h in mean heart rate interval and coefficient of irregularity. It seems that the mean heart rate interval in 1-hour periods between 11 AM and 2 PM might be predictive for 24-hour data. Short time recordings of the coefficient of irregularity of heart rate in AFib patients at this moment are not useful in clinical practice for long-term prognosis of ventricular irregularity. PMID:25276150

  17. Relationship between ammonia, heart rate, and exertion in McArdle's disease.

    PubMed

    Coakley, J H; Wagenmakers, A J; Edwards, R H

    1992-02-01

    We studied plasma ammonia and exercise tolerance in six patients with McArdle's disease (myophosphorylase deficiency, type V glycogenosis) during incremental cycle ergometry. Tests were performed either in the postabsorptive state or after supplementation with branched-chain amino and 2-oxoacids and glucose. Glucose and branched-chain 2-oxoacid combined increased total work performed from control 49 +/- 22 to 80 +/- 36 kJ (P less than 0.05). Glucose alone also improved total work performed from 49 +/- 22 to 64 +/- 33 kJ (P less than 0.05). Branched-chain 2-oxoacids alone had a variable effect, and branched-chain amino acids were of no benefit. Correlations between plasma ammonia and heart rate for individual patients were r = 0.99, P less than 0.01; r = 0.95, P less than 0.01; r = 0.84, P less than 0.01; r = 0.76, P less than 0.01; r = 0.73, P less than 0.01; and r = 0.63, P less than 0.05 and between ammonia and perceived exertion for all patients combined was r = 0.70, P less than 0.0001. In two patients, correlation of ammonia with heart rate at a power output of 60 W was r = 0.91, P less than 0.001 and at 40 W was r = 0.77, P less than 0.001. We conclude that ammonia is either a mediator or a marker of the metabolic events leading to fatigue. PMID:1539642

  18. Muscular contraction mode differently affects autonomic control during heart rate matched exercise.

    PubMed

    Weippert, Matthias; Behrens, Martin; Gonschorek, Ray; Bruhn, Sven; Behrens, Kristin

    2015-01-01

    The precise contributions of afferent feedback to cardiovascular and respiratory responses to exercise are still unclear. The aim of this crossover study was to assess whether and how autonomic cardiovascular and respiratory control differed in response to dynamic (DYN) and isometric contractions (ISO) at a similar, low heart rate (HR) level. Therefore, 22 healthy males (26.7 ± 3.6 yrs) performed two kinds of voluntary exercises at similar HR: ISO and DYN of the right quadriceps femoris muscle. Although HR was eqivalent (82 ± 8 bpm for DYN and ISO, respectively), rating of exertion, blood pressures, and rate pressure product were higher, whereas breathing frequency, minute ventilation, oxygen uptake and carbon dioxide output were significantly lower during ISO. Tidal volume, end-tidal partial pressures of O2 and CO2, respiratory exchange ratio and capillary blood lactate concentration were comparable between both contraction modes. Heart rate variability (HRV) indicators, SDNN, HF-Power and LF-Power, representing both vagal and sympathetic influences, were significantly higher during ISO. Sample entropy, a non-linear measure of HRV was also significantly affected by contraction mode. It can be concluded that, despite the same net effect on HR, the quality of cardiovascular control during low intensity exercise is significantly different between DYN and ISO. HRV analysis indicated a sympatho-vagal coactivation during ISO. Whether mechanoreceptor feedback alone, a change in central command, or the interaction of both mechanisms is the main contributor of the distinct autonomic responses to the different exercise modes remains to be elucidated. PMID:26042047

  19. Muscular contraction mode differently affects autonomic control during heart rate matched exercise

    PubMed Central

    Weippert, Matthias; Behrens, Martin; Gonschorek, Ray; Bruhn, Sven; Behrens, Kristin

    2015-01-01

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

  20. Effects of Moderate and Vigorous Physical Activity on Heart Rate Variability in a British Study of Civil Servants

    Microsoft Academic Search

    Kirsten L. Rennie; Harry Hemingway; Meena Kumari; Eric Brunner; Marek Malik; Michael Marmot

    2003-01-01

    Physical inactivity and low resting heart rate variability (HRV) are associated with increased coronary heart disease incidence. In the Whitehall II study of civil servants aged 45-68 years (London, United Kingdom, 1997- 1999), the strength of the association of moderate and vigorous activity with higher HRV was examined. Five- minute recordings of heart rate and HRV measures were obtained from

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

    ERIC Educational Resources Information Center

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

    2011-01-01

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

  2. Interviewer's ratings of personality: can these ratings predict job performance

    E-print Network

    Archuleta, Kathryn Diane

    1998-01-01

    The link between personality and job performance has usually been studied using self-report personality data. The present study looked at whether an interviewer's ratings of an applicant's personality can predict future ...

  3. Effects of acupuncture on heart rate variability in normal subjects under fatigue and non-fatigue state

    Microsoft Academic Search

    Zengyong Li; Chengtao Wang; Arthur F. T. Mak; Daniel H. K. Chow

    2005-01-01

    The objective of this study was to assess the effects of acupuncture applied at Hegu (LI 4) points and Neiguan (PC6) points on heart rate variability (HRV) in normal subjects under fatigue and non-fatigue states using power spectral analysis. Twenty-nine normal male subjects were randomly divided into three groups. Subjects in Group A and Group B performed a simulated driving

  4. Application of a fetal scalp electrode for continuous fetal heart rate monitoring during an ex utero intrapartum treatment.

    PubMed

    Kaneko, Masatoki; Tokunaga, Shunichi; Mukai, Motoi; Machigashira, Seirou; Maki, Youhei; Kodama, Yuki; Sameshima, Hiroshi; Ikenoue, Tsuyomu

    2011-02-01

    Fetal monitoring is required to avoid hypoxic injury during ex utero intrapartum treatment (EXIT). We performed a tracheostomy under EXIT in a case of suspected airway obstruction caused by a cervical teratoma. The scalp electrode was applied for continuous fetal heart rate monitoring. This device enabled us to promptly deal with fetal bradycardia caused by cord compression. We describe here the usefulness of the fetal scalp electrode for fetal monitoring under EXIT. PMID:21292069

  5. Lowering heart rate with an optimised breathing protocol for prospectively ECG-triggered CT coronary angiography

    PubMed Central

    Husmann, L; Herzog, B A; Pazhenkottil, A P; Buechel, R R; Nkoulou, R; Ghadri, J R; Valenta, I; Burger, I A; Gaemperli, O; Wyss, C A; Kaufmann, P A

    2011-01-01

    Objectives The aim was to prospectively characterise the effect of the level of breath-hold on heart rate in CT coronary angiography (CTCA) with prospective electrocardiogram (ECG) triggering and its impact on coronary artery attenuation. Methods 260 patients (86 women; mean age 59 ± 11 years) underwent 64-slice CTCA using prospective ECG triggering. Prior to CTCA, heart rates were recorded during 15 s of breath-hold at three different levels of inspiration (normal, intermediate and deep). The inspiration level with the lowest heart rate was chosen for actual CTCA scanning. Coronary artery attenuation was measured, and the presence of backflow of contrast material into the inferior vena cava (as an indicator of increased intrathoracic pressure) was recorded. Results The mean heart rate at breath-hold was significantly different for the three inspiration levels (normal, 60 ± 8 bpm; intermediate, 59 ± 8 bpm; deep, 57 ± 7 bpm; p<0.001). The maximum heart rate reduction in each patient at breath-hold averaged 5.3 ± 5.1 bpm, and was observed at a normal inspiration depth in 23 (9%) patients, at an intermediate inspiration depth in 102 (39%) patients and at deep inspiration in 135 (52%) patients. Overall, there was no association between the level of breath-hold and coronary vessel attenuation (p-value was not significant). However, the backflow of contrast material into the inferior vena cava (n = 26) was found predominantly at deep inspiration levels (p<0.001), and, when it occurred, it was associated with reduced coronary attenuation compared with patients with no backflow (p<0.05). Conclusion The breath-hold level to best reduce heart rate for CTCA should be individually assessed prior to scanning because a mean heart rate reduction of 5 bpm can be achieved. PMID:21849364

  6. RESPIRATOR PERFORMANCE RATING TABLES FOR NONTEMPERATE ENVIRONMENTS

    Microsoft Academic Search

    Arthur T. Johnson; Corey M. Grove; Ronald A. Weiss

    1992-01-01

    Respirator performance rating tables have been constructed for hot, humid (29°C, 95% RH); hot, dry (49°C, 30% RH); and cold, dry (?32°C, 70% RH) conditions. These tables convey expected wearer performance percentages compared to unmasked workers for various mask elements and work rates. The hot, humid condition was found to be the most severe overall. Many table entries approach 100%,

  7. Adaptive change detection in heart rate trend monitoring in anesthetized children.

    PubMed

    Yang, Ping; Dumont, Guy; Ansermino, J Mark

    2006-11-01

    The proposed algorithm is designed to detect changes in the heart rate trend signal which fits the dynamic linear model description. Based on this model, the interpatient and intraoperative variations are handled by estimating the noise covariances via an adaptive Kalman filter. An exponentially weighted moving average predictor switches between two different forgetting coefficients to allow the historical data to have a varying influence in prediction. The cumulative sum testing of the residuals identifies the change points online. The algorithm was tested on a substantial volume of real clinical data. Comparison of the proposed algorithm with Trigg's approach revealed that the algorithm performs more favorably with a shorter delay. The receiver operating characteristic curve analysis indicates that the algorithm outperformed the change detection by clinicians in real time. PMID:17073326

  8. Heart rate variation and electroencephalograph--the potential physiological factors for thermal comfort study.

    PubMed

    Yao, Y; Lian, Z; Liu, W; Jiang, C; Liu, Y; Lu, H

    2009-04-01

    Human thermal comfort researches mainly focus on the relation between the environmental factors (e.g. ambient temperature, air humidity, and air velocity, etc.) and the thermal comfort sensation based on a large amount of subjective field investigations. Although some physiological factors, such as skin temperature and metabolism were used in many thermal comfort models,they are not enough to establish a perfect thermal comfort model. In this paper,another two physiological factors, i.e. heart rate variation (HRV) and electroencephalograph (EEG), are explored for the thermal comfort study. Experiments were performed to investigate how these physiological factors respond to the environmental temperatures, and what is the relationship between HRV and EEG and thermal comfort. The experimental results indicate that HRV and EEG may be related to thermal comfort, and they may be useful to understand the mechanism of thermal comfort. PMID:19348034

  9. Patterns of Interspecific Variation in the Heart Rates of Embryonic Reptiles

    PubMed Central

    Du, Wei-Guo; Ye, Hua; Zhao, Bo; Pizzatto, Ligia; Ji, Xiang; Shine, Richard

    2011-01-01

    New non-invasive technologies allow direct measurement of heart rates (and thus, developmental rates) of embryos. We applied these methods to a diverse array of oviparous reptiles (24 species of lizards, 18 snakes, 11 turtles, 1 crocodilian), to identify general influences on cardiac rates during embryogenesis. Heart rates increased with ambient temperature in all lineages, but (at the same temperature) were faster in lizards and turtles than in snakes and crocodilians. We analysed these data within a phylogenetic framework. Embryonic heart rates were faster in species with smaller adult sizes, smaller egg sizes, and shorter incubation periods. Phylogenetic changes in heart rates were negatively correlated with concurrent changes in adult body mass and residual incubation period among the lizards, snakes (especially within pythons) and crocodilians. The total number of embryonic heart beats between oviposition and hatching was lower in squamates than in turtles or the crocodilian. Within squamates, embryonic iguanians and gekkonids required more heartbeats to complete development than did embryos of the other squamate families that we tested. These differences plausibly reflect phylogenetic divergence in the proportion of embryogenesis completed before versus after laying. PMID:22174948

  10. Heart Rate Variability and its Correlation with Pulmonary Function Test of Smokers

    PubMed Central

    Behera, Joshil Kumar; Sood, Sushma; Kumar, Naresh; Sharma, Kirti; Mishra, Reshmi; Roy, Prasanta Saha

    2013-01-01

    Context: Though many studies have been conducted on the effect of chronic smoking on pulmonary function test (PFT) and heart rate variability (HRV), no study has found a correlation between the pulmonary function test and heart rate variability parameters so far. Aim: The aim was to study if there was a correlation, if any, between PFT and HRV. Settings and Design: Thirty male subjects who were chronic smokers of at least 10 pack years and another 30 nonsmoking healthy males were included in the study and were matched for age, height, weight, and body surface area. Materials and Methods: PFT and HRV were performed on these subjects and a correlation was statistically derived. Statistical Analysis Used: Spearman?s correlation coefficient was used for the analysis of HRV and PFT. Multiple stepwise regression analysis was used subsequently. Results: HF and LF showed correlation coefficients of 0.378 and-0.383 with forced expiratory volume in the first second (FEV 1) and peak expiratory flow rate (PEFR), respectively. It was found that only FEV 1/FVC was having a statistically significant regression coefficient with HF the R-value was found to be 0.425 while with other parameters, it was not significant. Conclusion: We conclude that smoking affects all the parameters of PFT and HRV. Since there is a correlation between PFT parameters (PEFR and FEV1) and HRV parameter (LF and HF), this can help us in predicting cardiac morbidity in chronic smokers. So HRV should be included as a routine test along with PFT in chronic smokers for early diagnosis of cardiac involvement. PMID:23580921

  11. Validation of heart rate extraction through an iPhone accelerometer

    Microsoft Academic Search

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

    2011-01-01

    Ubiquitous medical technology may provide advanced utility for evaluating the status of the patient beyond the clinical environment. The iPhone provides the capacity to measure the heart rate, as the iPhone consists of a 3-axis accelerometer that is sufficiently sensitive to perceive tiny body movements caused by heart pumping. In this preliminary study, an iPhone was tested and evaluated as

  12. Computerised analysis of the fetal heart rate and relation to acidaemia at delivery

    Microsoft Academic Search

    Bryony K Strachan; Daljit S Sahota; Willem J van Wijngaarden; David K James; Allan M. Z Chang

    2001-01-01

    Objective To identify the individual features of the computerised analysis of the cardiotocograph that relate to arterial pH and base deficit at delivery.Design Retrospective observational study.Setting Teaching hospital labour wards.Participants 679 women requiring continuous intrapartum fetal monitoring.Methods Fetal heart and uterine contraction data were obtained using the Nottingham Fetal ECG monitor. Fetal heart rate patterns for the last half-hour preceding

  13. Field test of a paradigm: hysteresis of heart rate in thermoregulation by a free-ranging lizard (Pogona barbata).

    PubMed Central

    Grigg, G C; Seebacher, F

    1999-01-01

    The discovery that changes in heart rate and blood flow allow some reptiles to heat faster than they cool has become a central paradigm in our understanding of reptilian thermoregulation. However, this hysteresis in heart rate has been demonstrated only in simplistic laboratory heating and cooling trials, leaving its functional significance in free-ranging animals unproven. To test the validity of this paradigm, we measured heart rate and body temperature (Tb) in undisturbed, free-ranging bearded dragons (Pogona barbata), the species in which this phenomenon was first described. Our field data confirmed the paradigm and we found that heart rate during heating usually exceeded heart rate during cooling at any Tb. Importantly, however, we discovered that heart rate was proportionally faster in cool lizards whose Tb was still well below the 'preferred Tb range' compared to lizards whose Tb was already close to it. Similarly, heart rate during cooling was proportionally slower the warmer the lizard and the greater its cooling potential compared to lizards whose Tb was already near minimum operative temperature. Further, we predicted that, if heart rate hysteresis has functional significance, a 'reverse hysteresis' pattern should be observable when lizards risked overheating. This was indeed the case and, during heating on those occasions when Tb reached very high levels (> 40 degrees C), heart rate was significantly lower than heart rate during the immediately following cooling phase. These results demonstrate that physiological control of thermoregulation in reptiles is more complex than has been previously recognized. PMID:10418165

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

    PubMed

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

    2015-02-01

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

  15. Nomenclature, categorization and usage of formulae to adjust QT interval for heart rate

    PubMed Central

    Rabkin, Simon W; Cheng, Xin Bo

    2015-01-01

    Assessment of the QT interval on a standard 12 lead electrocardiogram is of value in the recognition of a number of conditions. A critical part of its use is the adjustment for the effect of heart rate on QT interval. A systematic search was conducted to identify studies that proposed formulae to standardize the QT interval by heart rate. A nomenclature was developed for current and subsequent equations based on whether they are corrective (QTc) or predictive (QTp). QTc formulae attempt to separate the dependence of the length of the QT interval from the length of the RR interval. QTp formulae utilize heart rate and the output QTp is compared to the uncorrected QT interval. The nomenclature consists of the first letter of the first author’s name followed by the next two consonance (whenever possible) in capital letters; with subscripts in lower case alphabetical letter if the first author develops more than one equation. The single exception was the Framingham equation, because this cohort has developed its own “name” amongst cardiovascular studies. Equations were further categorized according to whether they were linear, rational, exponential, logarithmic, or power based. Data show that a person’s QT interval adjusted for heart rate can vary dramatically with the different QTc and QTp formulae depending on the person’s heart rate and QT interval. The differences in the QT interval adjustment equations encompasses values that are considered normal or significant prolonged. To further compare the equations, we considered that the slope of QTc versus heart rate should be zero if there was no correlation between QT and heart rate. Reviewing a sample of 107 patient ECGs from a hospital setting, the rank order of the slope - from best (closest to zero) to worst was QTcDMT, QTcRTHa, QTcHDG, QTcGOT, QTcFRM, QTcFRD, QTcBZT and QTcMYD. For two recent formulae based on large data sets specifically QTcDMT and QTcRTHa, there was no significant deviation of the slope from zero. In summary a nomenclature permits easy reference to QT formulae that adjust for heart rate. Twenty different formulae can produce discordant calculations of an adjusted QT interval. While the formulae developed by Bazett and Fridericia (QTcBZT and QTcFRD respectively) may continue to be used clinically, recent formulae from large population studies specifically QTcDMT and QTcRTHa appear to be better to adjust QT for heart rate in clinical practice.

  16. Physical activity is a major contributor to the ultra low frequency components of heart rate variability

    Microsoft Academic Search

    J M Serrador; H C Finlayson; R L Hughson

    1999-01-01

    OBJECTIVETo investigate the link between changes in level of physical activity and the pattern of heart rate variability during long term ambulatory monitoring.DESIGNHeart rate variability was measured simultaneously with a quantitative indicator of muscle activity by electromyography (EMG) in five men and five women while they did activities typical of daily life or while they rested for 2–3 hours. Spectral

  17. Rhythm Control versus Rate Control for Atrial Fibrillation and Heart Failure

    Microsoft Academic Search

    Denis Roy; Mario Talajic; D. George Wyse; Paul Dorian; Kerry L. Lee; Martial G. Bourassa; J. Malcolm O. Arnold; Alfred E. Buxton; A. John Camm; Stuart J. Connolly; Marc Dubuc; Anique Ducharme; Peter G. Guerra; Stefan H. Hohnloser; Jean Lambert; Jean-Yves Le Heuzey; Gilles O'Hara; Ole Dyg Pedersen; Jean-Lucien Rouleau; Bramah N. Singh; Lynne Warner Stevenson; William G. Stevenson; Bernard Thibault; Albert L. Waldo

    2008-01-01

    Methods We conducted a multicenter, randomized trial comparing the maintenance of sinus rhythm (rhythm control) with control of the ventricular rate (rate control) in patients with a left ventricular ejection fraction of 35% or less, symptoms of congestive heart failure, and a history of atrial fibrillation. The primary outcome was the time to death from cardiovascular causes. Results A total

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

    ERIC Educational Resources Information Center

    DeWeese, Jo

    2009-01-01

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

  19. ORIGINAL PAPER Modeling Heart Rate Regulation--Part I: Sit-to-stand Versus

    E-print Network

    Olufsen, Mette Sofie

    in arterial blood pressure, and an immediate decrease of blood flow to the brain. The reduction in arterial uses blood pressure as an input to predict baroreflex firing-rate, which in turn is used to predict of sympathetic and parasympathetic outflow, are then used to estimate the heart rate response. Dynamics

  20. Mood, Blood Pressure, and Heart Rate at Work: An Experience-Sampling Study

    Microsoft Academic Search

    Remus Ilies; Nikos Dimotakis; David Watson

    2010-01-01

    We describe a study that examined the distinctiveness of momentary positive and negative affect (PA and NA) and their relationships with blood pressure and heart rate at work in a sample of 67 full-time employees who provided psychological and physiological measurements multiple times a day, over 10 working days. These employees recorded their subjective ratings on personal digital assistant devices

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

    PubMed

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

    2009-01-01

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

  2. Analysis of heart rate control to assess thermal sensitivity responses in Brazilian toads.

    PubMed

    Natali, J E S; Santos, B T; Rodrigues, V H; Chauí-Berlinck, J G

    2014-10-24

    In anurans, changes in ambient temperature influence body temperature and, therefore, energy consumption. These changes ultimately affect energy supply and, consequently, heart rate (HR). Typically, anurans living in different thermal environments have different thermal sensitivities, and these cannot be distinguished by changes in HR. We hypothesized that Rhinella jimi (a toad from a xeric environment that lives in a wide range of temperatures) would have a lower thermal sensitivity regarding cardiac control than R. icterica (originally from a tropical forest environment with a more restricted range of ambient temperatures). Thermal sensitivity was assessed by comparing animals housed at 15° and 25°C. Cardiac control was estimated by heart rate variability (HRV) and heart rate complexity (HRC). Differences in HRV between the two temperatures were not significant (P=0.214 for R. icterica and P=0.328 for R. jimi), whereas HRC differences were. All specimens but one R. jimi had a lower HRC at 15°C (all P<0.01). These results indicate that R. jimi has a lower thermal sensitivity and that cardiac control is not completely dependent on the thermal environment because HRC was not consistently different between temperatures in all R. jimi specimens. This result indicates a lack of evolutive trade-offs among temperatures given that heart rate control at 25°C is potentially not a constraint to heart rate control at 15°C. PMID:25351239

  3. Analysis of heart rate control to assess thermal sensitivity responses in Brazilian toads.

    PubMed

    Natali, J E S; Santos, B T; Rodrigues, V H; Chauí-Berlinck, J G

    2015-01-01

    In anurans, changes in ambient temperature influence body temperature and, therefore, energy consumption. These changes ultimately affect energy supply and, consequently, heart rate (HR). Typically, anurans living in different thermal environments have different thermal sensitivities, and these cannot be distinguished by changes in HR. We hypothesized that Rhinella jimi (a toad from a xeric environment that lives in a wide range of temperatures) would have a lower thermal sensitivity regarding cardiac control than R. icterica (originally from a tropical forest environment with a more restricted range of ambient temperatures). Thermal sensitivity was assessed by comparing animals housed at 15° and 25°C. Cardiac control was estimated by heart rate variability (HRV) and heart rate complexity (HRC). Differences in HRV between the two temperatures were not significant (P=0.214 for R. icterica and P=0.328 for R. jimi), whereas HRC differences were. All specimens but one R. jimi had a lower HRC at 15°C (all P<0.01). These results indicate that R. jimi has a lower thermal sensitivity and that cardiac control is not completely dependent on the thermal environment because HRC was not consistently different between temperatures in all R. jimi specimens. This result indicates a lack of evolutive trade-offs among temperatures given that heart rate control at 25°C is potentially not a constraint to heart rate control at 15°C. PMID:25493382

  4. Acoustic features of prairie vole (Microtus ochrogaster) ultrasonic vocalizations covary with heart rate.

    PubMed

    Stewart, Adam Michael; Lewis, Gregory F; Yee, Jason R; Kenkel, William M; Davila, Maria I; Sue Carter, C; Porges, Stephen W

    2015-01-01

    Vocalizations serve as a conspecific social communication system among mammals. Modulation of acoustic features embedded within vocalizations is used by several mammalian species to signal whether it is safe or dangerous to approach conspecific and heterospecific mammals. As described by the Polyvagal Theory, the phylogenetic shift in the evolution of mammals involved an adaptive neuroanatomical link between the neural circuits regulating heart rate and the muscles involved in modulating the acoustic features of vocalizations. However, few studies have investigated the covariation between heart rate and the acoustic features of vocalizations. In the current study, we document that specific features of vocalizations covary with heart rate in a highly social and vocal mammal, the prairie vole (Microtus ochrogaster). Findings with the prairie vole illustrate that higher pitch (i.e., fundamental frequency) and less variability in acoustic features of vocalizations (i.e., less vocal prosody) are associated with elevated heart rate. The study provides the first documentation that the acoustic features of prairie vole vocalizations may function as a surrogate index of heart rate. PMID:25447483

  5. Heart rate and behavioural responses of crib-biting horses to two acute stressors.

    PubMed

    Minero, M; Canali, E; Ferrante, V; Verga, M; Odberg, F O

    1999-10-01

    The heart rate and behaviour of 14 adult saddle horses, eight crib-biters and six normal controls, were investigated. Initially, the relationship between crib-biting and heart rate was investigated while the horses were undisturbed. The horses were tested when restrained with a lip twitch, and assessed when they were exposed suddenly to the rapid inflation of a balloon. The heart rate of the crib-biters during crib-biting was lower than during other behaviours. The crib-biters had a higher overall mean heart rate (P<0.05) suggesting that they may have had a higher basal sympathetic activity. After the application of the twitch, all the horses had a transient increase in heart rate which returned to basal values more rapidly in the crib-biters. The crib-biters were less reactive to the lip twitch, five of the six investigated remaining calm, and after the release of the twitch, they spent more time nibbling (P<0.05) than the control horses. The crib-biters reacted more strongly to the inflation of the balloon (three of the six reacted), and after it had been inflated they spent more time walking in the box. PMID:10755589

  6. Circadian variation of heart rate is affected by environment: a study of continuous electrocardiographic monitoring in members of a symphony orchestra.

    PubMed

    Mulcahy, D; Keegan, J; Fingret, A; Wright, C; Park, A; Sparrow, J; Curcher, D; Fox, K M

    1990-12-01

    Twenty four hour ambulatory ST segment monitoring was performed on 48 members (43 players and five members of the management/technical team) of the British Broadcasting Corporation (BBC) symphony orchestra without a history of cardiac disease. This period included final rehearsals and live performances (for audience and radio) of music by Richard Strauss and Mozart at the Royal Festival Hall (n = 36) and Rachmaninov and Tchaikovsky at the Barbican Arts Centre (n = 21). During the period of monitoring one person (2%) had transient ST segment changes. Mean heart rates were significantly higher during the live performances than during the rehearsals. Mean heart rates during the live performance of Rachmaninov and Tchaikovsky were significantly higher than during Strauss and Mozart in those (n = 6) who were monitored on both occasions. Mean heart rates in the management and technical team were higher than those of the players. The recognised circadian pattern of heart rate, with a peak in the morning waking hours, was altered similarly during both concert days, with a primary peak occurring in the evening hours and a lesser peak in the morning for both musicians and management/technical staff. This study showed that environmental factors are of primary importance in defining the circadian pattern of heart rate. This has important implications when identifying peak periods of cardiovascular stress and tailoring drug treatment for patients with angina pectoris. PMID:2271347

  7. Validation of pulse rate variability as a surrogate for heart rate variability in chronically instrumented rabbits

    PubMed Central

    Pellegrino, Peter R.; Schiller, Alicia M.

    2014-01-01

    Heart rate variability (HRV) is a function of cardiac autonomic tone that is widely used in both clinical and animal studies. In preclinical studies, HRV measures are frequently derived using the arterial pulse waveform from an implanted pressure telemetry device, termed pulse rate variability (PRV), instead of the electrocardiogram signal in accordance with clinical guidelines. The acceptability of PRV as a surrogate for HRV in instrumented animals is unknown. Using rabbits implanted with intracardiac leads and chronically implanted pressure transducers, we investigated the correlation and agreement of time-domain, frequency-domain, and nonlinear indexes of HRV and PRV at baseline. We also investigated the effects of ventricular pacing and autonomic blockade on both measures. At baseline, HRV and PRV time- and frequency-domain parameters showed robust correlations and moderate to high agreement, whereas nonlinear parameters showed slightly weaker correlations and varied agreement. Ventricular pacing almost completely eliminated HRV, and spectral analysis of the PRV signal revealed a HRV-independent rhythm. After cardiac autonomic blockade with atropine or metoprolol, the changes in time- and non-normalized frequency-domain measures of PRV continued to show strong correlations and moderate to high agreement with corresponding changes in HRV measures. Blockade-induced changes in nonlinear PRV indexes correlated poorly with HRV changes and showed weak agreement. These results suggest that time- and frequency-domain measures of PRV are acceptable surrogates for HRV even in the context of changing cardiac autonomic tone, but caution should be used when nonlinear measures are a primary end point or when HRV is very low as HRV-independent rhythms may predominate. PMID:24791786

  8. Beat-to-beat detection of fetal heart rate: Doppler ultrasound cardiotocography compared to direct ECG cardiotocography in time and frequency domain

    Microsoft Academic Search

    Chris H. L. Peters; Edith D. M. ten Broeke; Peter Andriessen; Barbara Vermeulen; Ralph C. M. Berendsen; Pieter F. F. Wijn; S. Guid Oei

    2004-01-01

    In order to obtain power spectral information on the fetal heart rate in stages of pregnancy earlier than labor an algorithm has been developed to calculate the fetal heart rate on a beat-to-beat basis from Doppler ultrasound cardiotocographic signals. The algorithm was evaluated by comparing the calculated fetal heart rate with the heart rate determined from direct ECG signals measured

  9. On the nature of heart rate variability in a breathing normal subject: A stochastic process analysis

    NASA Astrophysics Data System (ADS)

    Buchner, Teodor; Petelczyc, Monika; ?ebrowski, Jan J.; Prejbisz, Aleksander; Kabat, Marek; Januszewicz, Andrzej; Piotrowska, Anna Justyna; Szelenberger, Waldemar

    2009-06-01

    Human heart rate is moderated by the autonomous nervous system acting predominantly through the sinus node (the main cardiac physiological pacemaker). One of the dominant factors that determine the heart rate in physiological conditions is its coupling with the respiratory rhythm. Using the language of stochastic processes, we analyzed both rhythms simultaneously taking the data from polysomnographic recordings of two healthy individuals. Each rhythm was treated as a sum of a deterministic drift term and a diffusion term (Kramers-Moyal expansion). We found that normal heart rate variability may be considered as the result of a bidirectional coupling of two nonlinear oscillators: the heart itself and the respiratory system. On average, the diffusion (noise) component measured is comparable in magnitude to the oscillatory (deterministic) term for both signals investigated. The application of the Kramers-Moyal expansion may be useful for medical diagnostics providing information on the relation between respiration and heart rate variability. This interaction is mediated by the autonomous nervous system, including the baroreflex, and results in a commonly observed phenomenon—respiratory sinus arrhythmia which is typical for normal subjects and often impaired by pathology.

  10. Does well-harmonized homeostasis exist in heart rate fluctuations? Time series analysis and model simulations.

    PubMed

    Shiau, Yuo-Hsien

    2009-03-12

    Analyzing heart rate variability from electrocardiographic recordings has been an important method for assessing cardiovascular autonomic regulation. Researchers have conducted extensive analyses on normal as well as pathological hearts, however, it is still unclear whether increasing or decreasing the complexity of heart rate variability is a characteristic of healthy systems. In this study, we find the existence of well-harmonized homeostasis in heart rate fluctuations, in particular, the evidence is verified among different individuals including healthy subjects, ICU patients, and one child with brainstem dysfunction. The methodology we used is composed of two parts, in which one is the consideration of reduction of cardiorespiratory fluctuations inherited in the original R-R intervals and the other is based upon the concept of nonlinear dynamics to construct the low-dimensional trajectory in the angle plot. The cross-correlation measure between the theoretical angle map and the numerically derived angle trajectory is used to separate recovery (0.73+/-0.13) from deterioration (0.25+/-0.08) of ICU patients. In addition, a simple physiologic (deterministic) model of the interaction between the cardiovascular system and baroreceptor control of arterial pressure is used to explain why homeostasis can exist in heart rate fluctuations. Our study provides a potential link between the clinical data and circulatory system. PMID:19162560

  11. Age-related disappearance of Mayer-like heart rate waves

    NASA Technical Reports Server (NTRS)

    Jarisch, W. R.; Ferguson, J. J.; Shannon, R. P.; Wei, J. Y.; Goldberger, A. L.

    1987-01-01

    The effect of age on the principal spectral components of heart rate obtained immediately after passive upright tilt was investigated in human subjects who underwent a 60-deg tilt over 9 sec. Two groups were examined, the first of which consisting of healthy male subjects aged 22-26 years, while the second was comprised of subjects aged 65-84 years on no medication; radiograms were recorded continuously beginning just prior to tilt until 3 min posttilt. The results of spectral analysis showed that elderly subjects did not exhibit the Mayer-like heart rate waves (the 0.07-0.09 Hz oscillations) that were present in the spectra of young subjects immediately after passive upright tilt. The findings are consistent with the concept of a 'dysautonomia of aging'. It is suggested that postural stress testing with spectral analysis of heart rate fluctuations may provide a useful way of assessing physiologic vs chronologic age.

  12. In vivo acceleration of heart relaxation performance by parvalbumin gene delivery

    PubMed Central

    Szatkowski, Michael L.; Westfall, Margaret V.; Gomez, Carlen A.; Wahr, Philip A.; Michele, Daniel E.; DelloRusso, Christiana; Turner, Immanuel I.; Hong, Katie E.; Albayya, Faris P.; Metzger, Joseph M.

    2001-01-01

    Defective cardiac muscle relaxation plays a causal role in heart failure. Shown here is the new in vivo application of parvalbumin, a calcium-binding protein that facilitates ultrafast relaxation of specialized skeletal muscles. Parvalbumin is not naturally expressed in the heart. We show that parvalbumin gene transfer to the heart in vivo produces levels of parvalbumin characteristic of fast skeletal muscles, causes a physiologically relevant acceleration of heart relaxation performance in normal hearts, and enhances relaxation performance in an animal model of slowed cardiac muscle relaxation. Parvalbumin may offer the unique potential to correct defective relaxation in energetically compromised failing hearts because the relaxation-enhancement effect of parvalbumin arises from an ATP-independent mechanism. Additionally, parvalbumin gene transfer may provide a new therapeutic approach to correct cellular disturbances in calcium signaling pathways that cause abnormal growth or damage in the heart or other organs. PMID:11160135

  13. Analysis of heart rate deflection points to predict the anaerobic threshold by a computerized method.

    PubMed

    Marques-Neto, Silvio R; Maior, Alex S; Maranhão Neto, Geraldo A; Santos, Edil L

    2012-07-01

    Many studies have used the heart rate deflection points (HRDPs) during incremental exercise tests, because of their strong correlation with the anaerobic threshold. The aim of this study was to evaluate the profile of the HRDPs identified by a computerized method and compare them with ventilatory and lactate thresholds. Twenty-four professional soccer players (age, 22 ± 5 years; body mass, 74 ± 7 kg; height 177 ± 7 cm) volunteered for the study. The subjects completed a Bruce-protocol incremental treadmill exercise test to volitional fatigue. Heart rate (HR) and alveolar gas exchange were recorded continuously at ?1 Hz during exercise testing. Subsequently, the time course of the HR was fit by a computer algorithm, and a set of lines yielding the lowest pooled residual sum of squares was chosen as the best fit. This procedure defined 2 HRDPs (HRDP1 and HRDP2). The HR break points averaged 43.9 ± 5.9 and 89.7 ± 7.5% of the VO2peak. The HRDP1 showed a poor correlation with ventilatory threshold (VT; r = 0.50), but HRDP2 was highly correlated to the respiratory compensation (RC) point (r = 0.98). Neither HRDP1 nor HRDP2 was correlated with LT1 (at VO2 = 2.26 ± 0.72 L·min(-1); r = 0.26) or LT2 (2.79 ± 0.59 L·min(-1); r = 0.49), respectively. LT1 and LT2 also were not well correlated with VT (2.93 ± 0.68 L·min(-1); r = 0.20) or RC (3.82 ± 0.60 L·min(-1); r = 0.58), respectively. Although the HR deflection points were not correlated to LT, HRDP2 could be identified in all the subjects and was strongly correlated with RC, consistent with a relationship to cardiorespiratory fatigue and endurance performance. PMID:22717984

  14. Hypoxia increases exercise heart rate despite combined inhibition of ?-adrenergic and muscarinic receptors.

    PubMed

    Siebenmann, C; Rasmussen, P; Sørensen, H; Bonne, T C; Zaar, M; Aachmann-Andersen, N J; Nordsborg, N B; Secher, N H; Lundby, C

    2015-06-15

    Hypoxia increases the heart rate response to exercise, but the mechanism(s) remains unclear. We tested the hypothesis that the tachycardic effect of hypoxia persists during separate, but not combined, inhibition of ?-adrenergic and muscarinic receptors. Nine subjects performed incremental exercise to exhaustion in normoxia and hypoxia (fraction of inspired O2 = 12%) after intravenous administration of 1) no drugs (Cont), 2) propranolol (Prop), 3) glycopyrrolate (Glyc), or 4) Prop + Glyc. HR increased with exercise in all drug conditions (P < 0.001) but was always higher at a given workload in hypoxia than normoxia (P < 0.001). Averaged over all workloads, the difference between hypoxia and normoxia was 19.8 ± 13.8 beats/min during Cont and similar (17.2 ± 7.7 beats/min, P = 0.95) during Prop but smaller (P < 0.001) during Glyc and Prop + Glyc (9.8 ± 9.6 and 8.1 ± 7.6 beats/min, respectively). Cardiac output was enhanced by hypoxia (P < 0.002) to an extent that was similar between Cont, Glyc, and Prop + Glyc (2.3 ± 1.9, 1.7 ± 1.8, and 2.3 ± 1.2 l/min, respectively, P > 0.4) but larger during Prop (3.4 ± 1.6 l/min, P = 0.004). Our results demonstrate that the tachycardic effect of hypoxia during exercise partially relies on vagal withdrawal. Conversely, sympathoexcitation either does not contribute or increases heart rate through mechanisms other than ?-adrenergic transmission. A potential candidate is ?-adrenergic transmission, which could also explain why a tachycardic effect of hypoxia persists during combined ?-adrenergic and muscarinic receptor inhibition. PMID:25888515

  15. Analysis of the correlation between ventricular depolarization events and heart rate in normal subjects using signal-averaged ECG

    Microsoft Academic Search

    P. R. B. Barbosa; J. Barbosa-Filho; J. Nadal

    2000-01-01

    Electrical and mechanical events of cardiac activity must adapt to the time course between successive heart beats to allow the appropriate function of the heart as a pump. This study was conducted to evaluate the influence of resting instantaneous heart rate (HR) on the duration of the events of the ventricular depolarization, using SAECG. High resolution ECG signals of 12

  16. Intensive home-care surveillance prevents hospitalization and improves morbidity rates among elderly patients with severe congestive heart failure

    Microsoft Academic Search

    Ran Kornowski; Doron Zeeli; Mordechai Averbuch; Ariel Finkelstein; Doron Schwartz; Menachem Moshkovitz; Baruch Weinreb; Rami Hershkovitz; Dalia Eyal; Michael Miller; Yoram Levo; Amos Pines

    1995-01-01

    The purpose of this study was to examine the impact of intensive home-care surveillance on morbidity rates of elderly patients with severe congestive heart failure. Forty-two patients aged 78 ± 8 years who had severe congestive heart failure (New York Heart Association functional classes III through IV, mean ejection fraction 27% ± 6%), were examined at least once a week

  17. Average Heart Rates of Hispanic and Caucasian Adolescents during Sleep: Longitudinal Analysis from the TuCASA Cohort

    PubMed Central

    Hedger-Archbold, Kristen; Sorensen, Seth T.; Goodwin, James L.; Quan, Stuart F.

    2014-01-01

    Objective: The current study describes sleeping heart rate patterns in an adolescent cohort of Hispanic and Caucasian children over approximately a 5-year period to determine how sex, ethnicity, and body mass index (BMI) contribute to sleeping heart rate patterns over time. Methods: Participants were recruited from a large urban school district in the southwest United States as part of the Tucson Children's Assessment of Sleep Apnea Study (TuCASA). Heart rate data was obtained through electrocardiogram (ECG) recordings during in-home polysomnography, approximately 5 years apart. Second-wave cohort data were analyzed to determine how age, sex, ethnicity, physical activity, and BMI contribute to average sleeping heart rates. The same variables were used to investigate how sleeping heart rate patterns change longitudinally from school-age (6–11 years) to adolescence (10–17 years) during sleep. Results: Female adolescents had significantly faster average heart rates during sleep. Sleeping heart rate decreased significantly with increasing age in the adolescent cohort. Although the Hispanic group had a statistically significant higher body mass index than Caucasians, there were no significant differences in heart rate observed between ethnicities or in those who were classified as obese (BMI ? 95th percentile for age). Longitudinal analysis between the school-aged and adolescent cohort revealed a significant overall decrease in heart rate across a 5-year period. Conclusions: Hispanic and Caucasian adolescents experience a similar decrease in sleeping heart rate with age. Female adolescents had significantly faster heart rates than males, and no significant differences were observed between Caucasians and Hispanics, or obese vs. nonobese adolescents. Citation: Hedger-Archbold K, Sorensen ST, Goodwin JL, Quan SF. Average heart rates of Hispanic and Caucasian adolescents during sleep: longitudinal analysis from the TuCASA cohort. J Clin Sleep Med 2014;10(9):991-995. PMID:25142769

  18. A simple method of measuring total daily energy expenditure and physical activity level from the heart rate in adult men

    Microsoft Academic Search

    A V Kurpad; R Raj; K N Maruthy; M Vaz

    2006-01-01

    Objective:To evaluate a simple method that uses only a heart rate monitor to predict total energy expenditure (TEE) and physical activity level (PAL) from 24 h heart rate (HR) measurements.Design:The simple method involved the determination of the physical activity ratio (PAR) from corresponding heart rate ratios (HRR) (ratio of observed to resting HR), from an individualized calibration curve relating activities

  19. An ontogenetic shift in the response of heart rates to temperature in the developing snapping turtle (Chelydra serpentina).

    PubMed

    Birchard

    2000-08-01

    The affect of acute changes in temperature on heart rates was investigated for the first time in a developing reptile. Heart rates were determined early and late in incubation in snapping turtle (Chelydra serpentina) eggs. Late in incubation heart rates at any given temperature were lower than those observed early in incubation. The results of temperature switching experiments late in incubation were consistent with thermal acclimation. PMID:10745125

  20. Heart rate as a risk factor for developing chronic kidney disease: longitudinal analysis of a screened cohort

    Microsoft Academic Search

    Taku Inoue; Kunitoshi Iseki; Chiho Iseki; Yusuke Ohya; Kozen Kinjo; Shuichi Takishita

    2009-01-01

    Background  High heart rate and chronic kidney disease (CKD) are both risk factors for cardiovascular morbidity and mortality. The relationship\\u000a between heart rate and the risk of developing CKD, however, has not been studied in a large screened cohort.\\u000a \\u000a \\u000a \\u000a Methods and results  We examined the relationship between heart rate and the risk of developing CKD in participants in a health evaluation program.

  1. Correlated and Uncorrelated Regions in Heart-Rate Fluctuations during Sleep

    NASA Astrophysics Data System (ADS)

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

    2000-10-01

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

  2. Fetal heart rate monitoring during ambulant labour using a modified adult radiotelemetry system.

    PubMed

    MacLennan, A H; Green, R C

    1979-08-01

    A commercially available adult radiotelemetry system has been adapted successfully to allow continuous fetal heart rate monitoring during labour in ambulant patients. The modifications necessary to the adult equipment and its routine use in a large maternity unit are described. High quality recordings were obtained from 90% of the patients studied, with minimal inconvenience to the patient. The telemetry system combined the benefits of intrapartum fetal heart rate monitoring with those of ambulation during labour, decreasing the patient anxiety often associated with visible fetal monitoring. PMID:293163

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

    NASA Astrophysics Data System (ADS)

    Lin, D. C.; Sharif, A.

    2010-06-01

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

  4. Ablation of swallowing-induced atrial tachycardia affects heart rate variability: a case report.

    PubMed

    Hojo, Rintaro; Fukamizu, Seiji; Ishikawa, Tae; Hayashi, Takekuni; Komiyama, Kota; Tanabe, Yasuhiro; Tejima, Tamotsu; Kobayashi, Yoichi; Sakurada, Harumizu

    2014-05-01

    A 47-year-old man underwent slow pathway ablation for slow-fast atrioventricular nodal reentrant tachycardia. Following the procedure, he felt palpitations while swallowing, and swallowing-induced atrial tachycardia was diagnosed. Swallowing-induced atrial tachycardia arose from the right atrium-superior vena cava junction and was cured by catheter ablation. After the procedure, the patient's heart rate variability changed significantly, indicating suppression of parasympathetic nerve activity. In this case, swallowing-induced atrial tachycardia was related to the vagal nerve reflex. Analysis of heart rate variability may be helpful in elucidating the mechanism of swallowing-induced atrial tachycardia. PMID:23893269

  5. Persistent Ratee Contaminants in Performance Appraisal.

    ERIC Educational Resources Information Center

    Van Fleet, David D.; Chamberlain, Howard

    The hypothesis that conventional approaches to evaluating contaminants in performance appraisal overlook important individual ratee effects was examined. A rating form was developed that consisted of the following dimensions and behaviors: warmth; guided discourse or indirect teaching methods; control of subject matter; enthusiasm and reinforcing;…

  6. Effects of Performance Context on Processing Speed and Performance Ratings

    Microsoft Academic Search

    Tiffany Jennings; Jerry K. Palmer; Adrain Thomas

    2004-01-01

    The present study demonstrated that the presence of evaluatively polarized context performances not only produces contrast and halo effects on judgments of a target performance, but also causes judgments to be made much faster. Processing speed and positive halo were highly correlated, supporting the notion that halo in performance ratings results from raters' recall and use of a single, general

  7. Long-duration correlation and atiractor topology of the heartbeat rate differ for healthy patients and those with heart failure

    E-print Network

    Teich, Malvin C.

    in estimates of the instantaneous heart rate.89'2733 In Fig. 1 , an instantaneous rate estimate is formedLong-duration correlation and atiractor topology of the heartbeat rate differ for healthy patients and those with heart failure Robert 0. Turcott and Malvin C. Teich Department of Electrical Engineering

  8. Effects of propranolol on recovery of heart rate variability following acute myocardial infarction and relation to outcome in the Beta-Blocker Heart Attack Trial

    Microsoft Academic Search

    Rachel Lampert; Jeannette R Ickovics; Catherine J Viscoli; Ralph I Horwitz; Forrester A Lee

    2003-01-01

    This study evaluated the effects of propranolol on recovery of heart rate variability (HRV) after acute myocardial infarction and its relation to outcome in the Beta-blocker Heart Attack Trial (BHAT). Beta blockers improve mortality after acute myocardial infarction, but through an unknown mechanism. Depressed HRV, a measure of autonomic tone, predicts mortality after acute myocardial infarction. Whether ? blockers influence

  9. Multivariate regression analysis of the influence of aortic pressure, end-diastolic pressure, and heart rate on left ventricular relaxation in isolated ejecting rat and guinea pig hearts

    Microsoft Academic Search

    Stefan F. J. Langer

    1999-01-01

    The effect of moderate changes of peak aortic and end-diastolic pressure and of heart rate on the left ventricular relaxation of isolated working rat and guinea pig hearts was investigated by multivariate regression analysis. Each of these three independent variables was set to three different levels, yielding 27 sets of data by combination in each experiment. Relaxation was quantified by

  10. EEG and Heart Rate Measures of Working Memory at 5 and 10 Months of Age

    PubMed Central

    Cuevas, Kimberly; Bell, Martha Ann; Marcovitch, Stuart; Calkins, Susan D.

    2013-01-01

    We recorded electroencephalogram (EEG; 6–9 Hz) and heart rate (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 electrode pairs) at both ages. WM-related decreases in HR were only present at 5 months, and WM-related increases in EEG coherence became more localized by 10 months. Regression analyses revealed that baseline-to-task changes in psychophysiology accounted for variability in WM performance at 10, but not 5, months. HR and EEG power (medial frontal and lateral frontal electrodes) were unique predictors of variability in 10-month WM performance. These findings are discussed in relation to frontal lobe development, and represent the first comprehensive longitudinal analysis of age-related changes in the behavioral and psychophysiological correlates of WM. PMID:22148943

  11. Toward Capturing Momentary Changes of Heart Rate Variability by a Dynamic Analysis Method

    PubMed Central

    Zhang, Haoshi; Zhu, Mingxing; Zheng, Yue; Li, Guanglin

    2015-01-01

    The analysis of heart rate variability (HRV) has been performed on long-term electrocardiography (ECG) recordings (12~24 hours) and short-term recordings (2~5 minutes), which may not capture momentary change of HRV. In this study, we present a new method to analyze the momentary HRV (mHRV). The ECG recordings were segmented into a series of overlapped HRV analysis windows with a window length of 5 minutes and different time increments. The performance of the proposed method in delineating the dynamics of momentary HRV measurement was evaluated with four commonly used time courses of HRV measures on both synthetic time series and real ECG recordings from human subjects and dogs. Our results showed that a smaller time increment could capture more dynamical information on transient changes. Considering a too short increment such as 10 s would cause the indented time courses of the four measures, a 1-min time increment (4-min overlapping) was suggested in the analysis of mHRV in the study. ECG recordings from human subjects and dogs were used to further assess the effectiveness of the proposed method. The pilot study demonstrated that the proposed analysis of mHRV could provide more accurate assessment of the dynamical changes in cardiac activity than the conventional measures of HRV (without time overlapping). The proposed method may provide an efficient means in delineating the dynamics of momentary HRV and it would be worthy performing more investigations. PMID:26172953

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

    PubMed

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

    1997-11-01

    Spectral analysis of heart rate variability is studied in 10 healthy growing premature infants to investigate the changes in autonomic balance achieved as a function of changes in skin temperature. Heart rate is obtained from ECG recordings and the power spectrum of beat-to-beat heart rate fluctuations is computed. The infants maintain mean rectal temperature within 36.3-37.2 degrees C, while skin temperature changes. The respiratory rate does not change at the different servocontrol set points. Heart rate is found to increase slightly, but consistently. The low-frequency band (0.02-0.2 Hz), reflecting the interplay of the sympathetic and parasympathetic tone and known to be maximum at the thermoneutral zone, is maximum at 35.5 and 36 degrees C and decreases gradually to a lower level at a servocontrol temperature of 36.5-37 degrees C. The high-frequency band (0.2-2.0 Hz), coinciding with the respiratory peak and reflecting parasympathetic activity, is significantly elevated at 36 degrees C (p < 0.01). The minimum low: high ratio, indicating the minimum sympathetic-parasympathetic balance and possibly reflecting the most comfortable conditions, occurs at 36 degrees C, although the differences are not statistically significant. Servocontrol skin temperature may thus be adapted, and possibly selected at 36 degrees C for growing premature infants in an attempt to achieve thermal comfort and more balanced autonomic activity. PMID:9538537

  13. Considerations in the assessment of heart rate variability in biobehavioral research

    PubMed Central

    Quintana, Daniel S.; Heathers, James A. J.

    2014-01-01

    Heart rate variability (HRV) refers to various methods of assessing the beat-to-beat variation in the heart over time, in order to draw inference on the outflow of the autonomic nervous system. Easy access to measuring HRV has led to a plethora of studies within emotion science and psychology assessing autonomic regulation, but significant caveats exist due to the complicated nature of HRV. Firstly, both breathing and blood pressure regulation have their own relationship to social, emotional, and cognitive experiments – if this is the case are we observing heart rate (HR) changes as a consequence of breathing changes? Secondly, experiments often have poor internal and external controls. In this review we highlight the interrelationships between HR and respiration, as well as presenting recommendations for researchers to use when collecting data for HRV assessment. Namely, we highlight the superior utility of within-subjects designs along with the importance of establishing an appropriate baseline and monitoring respiration. PMID:25101047

  14. Time-frequency analysis of heart rate time series

    Microsoft Academic Search

    V. P. S. Naidu; P. Mahalakshmi

    2004-01-01

    Time-frequency distribution techniques viz., STFT, WVD and CWT were studied using simulated HRTS data. It is concluded that CWT showed better performance in time-frequency representation. This technique is extended to compute the real HRTS. It is observed from the CWT spectrum that more power is concentrated in low frequency region in MI patients and vice versa in case of normal

  15. Respiratory influence on heart rate in diabetes mellitus

    Microsoft Academic Search

    G Sundkvist; L O Almér; B Lilja

    1979-01-01

    To find a simple and accurate test of autonomic nervous dysfunction in diabetes mellitus, 41 insulin-dependent diabetics and 25 controls were investigated. The diabetics, none of whom had symptoms of autonomic dysfunction, were tested for retinopathy and sensory neuropathy. Each subject also performed maximal deep-breathing procedures while undergoing electrocardiographic recording: in normal subjects the intervals are shortened during inspiration and

  16. Mean Platelet Volume in Patients with Obstructive Sleep Apnea and Its Relationship with Simpler Heart Rate Derivatives

    PubMed Central

    Akyüz, Ayd?n; Akkoyun, Dursun Çayan; Oran, Mustafa; De?irmenci, Hasan; Alp, Recep

    2014-01-01

    Some studies show increased mean platelet volume (MPV) in obstructive sleep apnea (OSA). The aim of this study was to evaluate MPV in OSA patients without cardiovascular risk factors and the possible association of heart rate derivatives with MPV. A total of 82 patients (aged 30–70 years) were divided into 2 groups according to the presence of either OSA or non-OSA as the control group. The OSA group consisted of 52 patients and the control group consisted of 30 subjects. Neither group was significantly different in terms of MPV values as well as heart rate (HR) derivatives such as minimum HR, maximum HR, the difference between maximum HR and minimum HR, mean HR, and heart rate performance index (HRPI) [(HR max. ? HR min.)/HR mean] (P > 0.05 for all variables). In multivariate analysis, platelet count and percentages of recording time spent at arterial oxygen saturation < 90% significant variables are associated with MPV (? ± SE: ?0.004 ± 0.002, 95% CI, ?0.008 to ?0.001; P = 0.034) and (? ± SE: 2.93 ± 1.93, 95% CI, 0.167 to 5.69; P = 0.038). Consequently, our findings predominantly suggest that there is a casual and reciprocal interaction between MPV and autonomic activation. PMID:25295213

  17. Equestrian expertise affecting physical fitness, body compositions, lactate, heart rate and calorie consumption of elite horse riding players

    PubMed Central

    Sung, Bong-Ju; Jeon, Sang-Yong; Lim, Sung-Ro; Lee, Kyu-Eon; Jee, Hyunseok

    2015-01-01

    Horse riding (HR) is a sport harmonized with rider and horse. HR is renowned as an effective sport for young and old women and men. There is rare study regarding comparison between elite horse riders and amateurs. We aimed to investigate comprehensive ranges of parameters such as change of lactate, heart rate, calorie, VO2max, skeletal muscle mass, body water, body fat, etc between amateurs and professionals to emphasize HR not only as a sport training but also as a therapeutic aspect. We performed 3 experiments for comparing physical fitness, body compositions, lactate value, heart rate and calorie consumption change before and after riding between amateurs and elites. Around 3 yr riding experienced elites are preeminent at balance capability compared to 1 yr riding experienced amateurs. During 18 min horse riding, skeletal muscle mass and body fat were interestingly increased and decreased, respectively. Lactate response was more sensitive in elites rather than amateurs and its recovery was reversely reacted. Exercise intensity estimated from heart rate was significantly higher in elites (P<0.05). The similar pattern of calorie consumption during riding between amateurs and elites was shown. Horse riding possibly induces various physiological (muscle strength, balance, oxidative capability, flexibility, and metabolic control) changes within body and is thus highly recommended as combined exercise for women, children, and aged as therapeutic and leisure sport activity.

  18. Saliva testosterone and heart rate variability in the professional symphony orchestra after "public faintings" of an orchestra member.

    PubMed

    Theorell, Töres; Liljeholm-Johansson, Yvonne; Björk, Helena; Ericson, Mats

    2007-07-01

    Musicians are sensitive to changes in their work environment. A 2-year longitudinal study with repeated observations was performed in two professional symphony orchestras. A representative sample from each one of them was selected, 15 and 16 members respectively. In one of them a wind player fainted twice in front of the audience shortly preceding and coinciding with the start of the study. Changes in two indicators that reflect regenerative/anabolic and parasympathetic tone, saliva testosterone concentration (STC) and very low-frequency power (VLFP) in heart rate variability were followed in relation to this dramatic change. Saliva samples and 24-h ECG heart rate variability recordings were collected on five occasions every 6 months during a 2-year period. No changes were seen in the control orchestra whereas the levels showed a pronounced rise in the intervention orchestra during the first part of the study, starting from low levels. VLFP showed a similar pattern, with initially low and then rising level in the intervention orchestra and higher stable level in the other group. In the total study group, a rise in STC over the whole observation period was significantly correlated with increase in VLFP and also significantly correlated with a decrease in low/high-frequency power ratio in heart rate variability. The changes observed in the anabolic/regenerative STC and the parasympathetically influenced VLFP may reflect changes in the work environment associated with the faintings. PMID:17560732

  19. 5th Conference of the European Study Group on Cardiovascular Oscillations Abstract--Heart rate variability is proposed as an indicator

    E-print Network

    . INTRODUCTION Heart Rate Variability (HRV) measurements are used as a marker of autonomic modulation of heart fluctuations in heart rate. These nonlinear variations would enable the cardiovascular system to respond more differences in heart rate variability were investigated. The hypothesis that HRV is higher in healthy women

  20. Analysis of Heart Rate and Blood Pressure Time Series Using a Two-Dimensional Autoregressive Model

    NASA Astrophysics Data System (ADS)

    Yoshida, Yutaka; Yokoyama, Kiyoko; Uehara, Akihiko; Kurata, Chinori; Takata, Kazuyuki

    We analyzed the feedback relationship between short-term fluctuations in heart rate and blood pressure in healthy persons and heart failure patients. Parameters derived from the feedback relationship between heart rate and blood pressure have been proposed. The purpose of the present study is to apply these parameters in estimating autonomic function or measuring physiological and mental workload. Electrocardiographs and beat-to-beat blood pressure were recorded in supine position at rest. The blood pressure was measured using arterial tonometry. The R—R interval and systolic blood pressure were fitted to two-dimensional autoregressive models, the relative power contribution in the frequency domain was calculated. The proposed parameters are the power contribution in the low-frequency range ( 0-0.15 Hz ) [ RS_LF, SR_LF ] and the power contribution in the high-frequency range ( 0.15-0.5 Hz ) [ RS_HF, SR_HF ]. RS_LF was significantly different between healthy persons and heart failure patients ( p<0.01 ). This parameter can be used to estimate autonomic depression caused by aging and heart failure. There were no correlations between the proposed parameters and the usual indices to evaluate autonomic function. It is considered that the proposed parameters can be used to evaluate physiological states that cannot be evaluated using existing methods.

  1. Effect of Rotating Acoustic Stimulus on Heart Rate Variability in Healthy Adults

    PubMed Central

    Roy, Bhaskar; Choudhuri, Raghabendra; Pandey, Ambarish; Bandopadhyay, Sajal; Sarangi, Sasmit; Kumar Ghatak, Sobhendu

    2012-01-01

    Acoustic stimulus can modulate the Autonomic Nervous System. However, previous reports on this topic are conflicting and inconclusive. In this study we have shown, how rotating acoustic stimulus, a novel auditory binaural stimulus, can change the autonomic balance of the cardiac system. We have used Heart rate Variability (HRV), an indicator of autonomic modulation of heart, both in time and frequency domain to analyze the effect of stimulus on 31 healthy adults. A decrease in the heart rate accompanied with an increase in SD and RMSSD indices on linear analysis was observed post-stimulation. In the Poincaré Plot, Minor Axis (SD1), Major Axis (SD2) and the ratio SD12 (SD1/SD2) increased after the stimulation. Post stimulus greater increment of SD12 with higher lag numbers of (M) beat to beat intervals, when compared to pre stimulus values, resulted in increased curvilinearity in the SD12 vs. Lag number plot. After stimulation,value of exponent alpha of Dretended Flactuation Analysis of HRV was found to be decreased. From these characteristic responses of the heart after the stimulus, it appears that rotating acoustic stimulus may be beneficial for the sympathovagal balance of the heart. PMID:23091566

  2. EFFECTS OF CHLORDIMEFORM ON HEART RATE AND BODY TEMPERATURE OF UNANESTHETIZED, UNRESTRAINED RATS

    EPA Science Inventory

    Heart rate (HR) and body temperature (TEMP) were monitored in unanesthetized, unrestrained adult rats following intraperitoneal administration of 0, 10, 30, or 60 mg/kg of the pesticide chlordimeform (CDM). Although significant decreases were observed in both HR and TEMP in all t...

  3. Heart Rate Variability – a Tool to Differentiate Positive and Negative Affective States in Pigs?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The causal neurophysiological processes, such as autonomic nervous system activity, that mediate behavioral and physiological reactivity to an environment have largely been ignored. Heart rate variability (HRV) analysis is a clinical diagnostic tool used to assess affective states (stressful and ple...

  4. Use of heart rate variability differentiates between physical and psychological states

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The major goal of animal welfare scientists is to determine when animals are experiencing a state of good welfare or poor welfare. The goal of this research was to determine if measures of heart rate variability can be used to differentiate whether animals are experiencing differing states of physi...

  5. Effects of work load, role ambiguity, and Type A personality on anxiety, depression, and heart rate

    Microsoft Academic Search

    Robert D. Caplan; Kenneth W. Jones

    1975-01-01

    Studied Type A personality (hard driving, persistent, involved in work) as a conditioner of the effects of quantitative work load and role ambiguity (stresses) on anxiety, depression, resentment, and heart rate (strains) among 73 male users (mean age, 23 yrs) of a university computer system that was approaching a 23-day shutdown. Each respondent was his own control. Stress, personality, and

  6. Ethnic differences in blood pressure and heart rate of Chicago school children.

    PubMed

    Levinson, S; Liu, K; Stamler, J; Stamler, R; Whipple, I; Ausbrook, D; Berkson, D

    1985-09-01

    In 1975-1978, the Chicago Department of Health conducted a screening program that included measurements of blood pressure, heart rate, height, weight, triceps skinfold thickness, and arm circumference, and calculation of body mass index and muscle circumference for non-public school children. Based on data on 4,086 boys and girls aged 5-10 years from the program, this study examined the ethnic differences in blood pressure and heart rate among children of white, black, Latino, and Oriental ethnicity. Mean levels for both systolic and diastolic blood pressure were higher for Oriental and black children than for white and Latino children. These differences were independent of age, height, weight, and skinfold thickness. The black children had a much lower mean heart rate than the other children. A seasonal variation was observed for systolic blood pressure, i.e., with each sex group, the mean systolic blood pressure adjusted for age, skinfold thickness, and height tended to be higher in spring than in fall and winter. (Note-- no child was screened during the summer because of summer break.) With control for season, ethnic differences in systolic blood pressure disappeared, but not the ethnic differences in diastolic blood pressure and heart rate. PMID:4025287

  7. In vivo cardiac phase response curve elucidates human respiratory heart rate variability

    E-print Network

    Pikovsky, Arkady

    In vivo cardiac phase response curve elucidates human respiratory heart rate variability Published information for successful reconstruction of the dynamics is the sensitivity of an oscillator to external-running conditions. We use this method to obtain the phase coupling functions describing cardio-respiratory

  8. Variations in Blood Pressure and Heart Rate in Conscious Rats with Cervical Lymphatic Blockade

    Microsoft Academic Search

    Yan-Hong Zheng; Zuo-Li Xia; Lian-Bi Chen; Xiao-Min Zhao; Qing Xia; Xi-Jun Song

    2008-01-01

    The possible effects of cervical lymphatic blockade (CLB) on a series of parameters in conscious freely moving rats were analysed. Blood pressure (BP) and heart rate (HR) for conscious male Sprague- Dawley rats at 1, 3, 7, 11, 15 and 21 days after a CLB or a sham operation were monitored continuously for 24 hours with a computerized recording system.

  9. Evaluation of Fetal Heart Rate Patterns during the Second Stage of Labor through Fetal Oximetry

    Microsoft Academic Search

    E. Salamalekis; N. Vitoratos; C. Loghis; N. Panayotopoulos; D. Kassanos; G. Creatsas

    1999-01-01

    The purpose of this study was to assess the feasibility and accuracy of fetal pulse oximetry during the second stage of labor in cases with abnormal fetal heart rate (FHR) patterns with reference to postpartum acid-base status and Apgar scores. Forty-eight parturients with normal and 20 parturients with abnormal FHR tracings during the second stage of labor were monitored by

  10. Brain Areas Controlling Heart Rate Variability in Tinnitus and Tinnitus-Related Distress

    E-print Network

    O'Toole, Alice J.

    Brain Areas Controlling Heart Rate Variability in Tinnitus and Tinnitus-Related Distress Sven Vanneste1,2 *, Dirk De Ridder1 1 Brai2 n, Tinnitus Research Initiative Clinic Antwerp & Department, Faculty of Medicine, University of Antwerp, Antwerp, Belgium Abstract Background: Tinnitus is defined

  11. Nonlinear analysis of heart rate variability within independent frequency components during the sleep–wake cycle

    Microsoft Academic Search

    Daniel E. Vigo; Javier Dominguez; Salvador M. Guinjoan; Mariano Scaramal; Eduardo Ruffa; Juan Solernó; Leonardo Nicola Siri; Daniel P. Cardinali

    2010-01-01

    Heart rate variability (HRV) is a complex signal that results from the contribution of different sources of oscillation related to the autonomic nervous system activity. Although linear analysis of HRV has been applied to sleep studies, the nonlinear dynamics of HRV underlying frequency components during sleep is less known. We conducted a study to evaluate nonlinear HRV within independent frequency

  12. Heart Rate Complexity in Response to Upright Tilt in Persons with Down Syndrome

    ERIC Educational Resources Information Center

    Agiovlasitis, Stamatis; Baynard, Tracy; Pitetti, Kenneth H.; Fernhall, Bo

    2011-01-01

    People with Down syndrome (DS) show altered autonomic response to sympatho-excitation. Cardiac autonomic modulation may be examined with heart rate (HR) complexity which is associated uniquely with cardiovascular risk. This study examined whether the response of HR complexity to passive upright tilt differs between persons with and without DS and…

  13. Casino gambling increases heart rate and salivary cortisol in regular gamblers

    Microsoft Academic Search

    Gerhard Meyer; Berthold P Hauffa; Manfred Schedlowski; Cornelius Pawlak; Michael A Stadler; Michael S Exton

    2000-01-01

    Background: Although the effects of gambling on cardiovascular parameters have been documented, no data exists describing the effect of gambling on stress hormone secretion. Our study investigated the effect of gambling on heart rate and salivary cortisol in a casino environment.Methods: Ten male gamblers participated in both an experimental and control session. In the experimental session, gamblers played a game

  14. Effects of social isolation and restraint on heart rate and behaviour of alpacas

    Microsoft Academic Search

    J. C. Pollard; R. P. Littlejohn

    1995-01-01

    Heart rate and behaviour of 16 yearling male alpacas were measured during spatial and visual isolation from other alpacas (Treatment I) and when a pair of familiar alpacas was present (Treatment G). In Experiment 1, subjects were free to move in a 2.4 m2 wire pen while in Experiment 2, subjects were held under manual restraint in the pen. In

  15. Mortality and Heart Rate in the Elderly: Role of Cognitive Impairment

    Microsoft Academic Search

    Francesco Cacciatore; Francesca Mazzella; Pasquale Abete; Luisa Viati; Gianluigi Galizia; Daniele DAmbrosio; Gaetano Gargiulo; Salvatore Russo; Claudia Visconti; David Della Morte; Nicola Ferrara; Franco Rengo

    2007-01-01

    Mortality related to heart rate (HR) increase in the elderly has not yet been well established. To ascertain the relationships among cognitive impairment (CI), mortality, and HR increase, the authors prospectively studied a random sample of elderly subjects stratified according to presence or absence of CI. Elderly subjects randomly selected in 1991 (n = 1332) were followed up for 12 years. Mortality

  16. Docosahexaenoic Acid but Not Eicosapentaenoic Acid Lowers Ambulatory Blood Pressure and Heart Rate in Humans

    Microsoft Academic Search

    Trevor A. Mori; Danny Q. Bao; Valerie Burke; Ian B. Puddey; Lawrence J. Beilin

    Animal studies suggest that the 2 major v3 fatty acids found in fish, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), may have differential effects on blood pressure (BP) and heart rate (HR). The aim of this study was to determine whether there were significant differences in the effects of purified EPA or DHA on ambulatory BP and HR in humans.

  17. Heart Rate Variability during Social Interactions in Children with and without Psychopathology: A Meta-Analysis

    ERIC Educational Resources Information Center

    Shahrestani, Sara; Stewart, Elizabeth M.; Quintana, Daniel S.; Hickie, Ian B.; Guastella, Adam J.

    2014-01-01

    Background: The inability to regulate autonomic activity during social interactions is believed to contribute to social and emotional dysregulation in children. Research has employed heart rate variability (HRV) during both socially engaging and socially disengaging dyadic tasks between children and adults to assess this. Methods: We conducted a…

  18. Pupillary and Heart Rate Reactivity in Children with Minimal Brain Dysfunction

    ERIC Educational Resources Information Center

    Zahn, Theodore P.; And Others

    1978-01-01

    In an attempt to replicate and extend previous findings on autonomic arousal and responsivity in children with minimal brain dysfunction (MBD), pupil size, heart rate, skin conductance, and skin temperature were recorded from 32 MBD and 45 control children (6-13 years old). (Author/CL)

  19. Combining GPS with heart rate monitoring to measure physical activity in children: A feasibility study

    Microsoft Academic Search

    J. Scott Duncan; Hannah M. Badland; Grant Schofield

    2009-01-01

    The recent development of global positioning system (GPS) receivers with integrated heart rate (HR) monitoring has provided a new method for estimating the energy expenditure associated with children's movement. The purpose of this feasibility study was to trial a combination of GPS surveillance and HR monitoring in 39 primary-aged children from New Zealand. Spatial location and HR data were recorded

  20. Changes in the Hurst Exponent of Heart Rate Variability during Physical Activity

    Microsoft Academic Search

    Naoko Aoyagi; Ken Kiyono; Zbigniew R. Struzik; Yoshiharu Yamamoto

    2005-01-01

    We examine fractal scaling properties of heart rate variability using detrended fluctuation analysis (DFA), during physical activity in healthy subjects. We analyze 11 records of healthy subjects, which include both usual daily activity and experimental exercise. The subjects were asked to ride on a bicycle ergometer for 2.5 hours, and maintained a heartbeat interval of 500-600 ms. In order to