PETER HOFMANN; SERGE P. VON DUVILLARD; FRANZ-JOSEF SEIBERT; ROCHUS POKAN; MANFRED WONISCH; LINDA M. LEMURA
HOFMANN, P., S. P. VON DUVILLARD, F-J. SEIBERT, R. POKAN, M. WONISCH, L. M. LEMURA, and G. SCHWABERGER. %HRmax target heart rate is dependent on heart rate performance curve deflection. Med. Sci. Sports Exerc., Vol. 33, No. 10, 2001, pp. 1726 -1731. The percent of maximal heart rate (%HRmax) model is widely used to determine training intensities in healthy subjects
PETER A. FARRELL; JACK H. WILMORE; EDWARD F. COYLE
A reduced heart rate at a standard exercise intensity is a well-established result of endurance training (see Barnard, 1975 for review). Since exercise heart rates are easily monitored, this parameter was identified as a potential predictor of performance in road racing. This report will concern itselfstrictly with the predictive power of exercise heart rates since other data from this study
FRANCOIS COTTIN; CLAIRE MEDIGUE; PIERRE-MARIE LEPRETRE; YVES PAPELIER; JEAN-PIERRE KORALSZTEIN; VERONIQUE BILLAT
COTTIN, F., C. MEDIGUE, P.-M. LEPRETRE, Y. PAPELIER, J.-P. KORALSZTEIN, and V. BILLAT. Heart Rate Variability during Exercise Performed below and above Ventilatory Threshold. Med. Sci. Sports Exerc., Vol. 36, No. 4, pp. 594 - 600, 2004. Purpose: To examine whether differences in heart rate variability (HRV) can distinguish sub- from supra-ventilatory-threshold exercise and whether the exercise duration at supra-threshold
Mullen, Richard; Faull, Andrea; Jones, Eleri S.; Kingston, Kieran
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
Luque-Casado, Antonio; Zabala, Mikel; Morales, Esther; Mateo-March, Manuel; Sanabria, Daniel
In the present study, we investigated the relation between cognitive performance and heart rate variability as a function of fitness level. We measured the effect of three cognitive tasks (the psychomotor vigilance task, a temporal orienting task, and a duration discrimination task) on the heart rate variability of two groups of participants: a high-fit group and a low-fit group. Two major novel findings emerged from this study. First, the lowest values of heart rate variability were found during performance of the duration discrimination task, compared to the other two tasks. Second, the results showed a decrement in heart rate variability as a function of the time on task, although only in the low-fit group. Moreover, the high-fit group showed overall faster reaction times than the low-fit group in the psychomotor vigilance task, while there were not significant differences in performance between the two groups of participants in the other two cognitive tasks. In sum, our results highlighted the influence of cognitive processing on heart rate variability. Importantly, both behavioral and physiological results suggested that the main benefit obtained as a result of fitness level appeared to be associated with processes involving sustained attention. PMID:23437276
exercise. Ten elite windsurfers [age: 20.93 (3.46) years; height: 178.10 (6.34) cm; body mass: 66.79 (5.90) kg] performed a laboratory maximal oxygen consumption (VO2max) trial and national windsurf a better result. Since then, the importance of physical training has taken up a larger part
Barbara Z. Tharp
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.
Thompson, Andrew G; Swain, David P; Branch, J David; Spina, Robert J; Grieco, Carmine R
Thompson, AG, Swain, DP, Branch, JD, Spina, RJ, and Grieco, CR. Autonomic response to tactical pistol performance measured by heart rate variability. J Strength Cond Res 29(4): 926-933, 2015-This study evaluated changes in autonomic tone during a tactical pistol competition. At rest and during a match, heart rate variability (HRV) was examined in 28 healthy subjects. Heart rate variability time-domain variables (including interbeat interval [IBI]) and frequency-domain variables (low frequency [LF], high frequency [HF], total power [TP]) measured during shooting were subtracted from those measured during rest to produce ?s. The shooting task involved several, rapid tactical maneuvers. Raw time to completion and inaccurate shots (points down [PDs]) were recorded and combined to form a match score where lower values indicated superior shooting performance. Mean (±SD) raw time was 135.9 ± 34.1 seconds, PDs were 78 ± 34, and match score was 175.3 ± 39.8. Shooting decreased IBI (i.e., increased heart rate) and LF. ?LF, ?HF, and ?TP were independent of ?IBI. Raw time was significantly (p ? 0.05) correlated to shooting IBI (r = 0.404) and ?IBI (r = -0.426). Points down were significantly correlated to ?TP (r = 0.416) and ?LF (r = 0.376). Match score was significantly correlated to ?IBI (r = -0.458), ?HF (r = 0.467), ?LF (r = 0.377), and ?TP (r = 0.451). In conclusion, individuals with a greater decrease in IBI (and thus heart rate) performed better by accomplishing the match faster. Individuals with less change in stress-related HRV measures (LF, HF, and TP) performed better through improved accuracy. Thus, HRV-derived sympathetic response is significantly related to shooting performance and should be used to assess marksmanship effectiveness under duress. PMID:25029000
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
Soon-Cheol Chung; Sunao Iwaki; Gye-Rae Tack; Jeong-Han Yi; Ji-Hye You; Ji-Hun Kwon
This study investigated the effect of 30% oxygen administration on verbal cognitive performance, blood oxygen saturation, and heart rate. Five male (24.6(±0.9) years) and five female (22.2(±1.9) years) college students were selected as the subjects for this study. Two psychological tests were developed to measure the performance level of verbal cognition. The experiment consisted of two runs: one was a
... safer than others. Learn more: All About Heart Rate (Pulse) Blood Pressure Vs. Heart Rate The AHA Recommendations for Physical ... of High Blood Pressure? 5 All About Heart Rate (Pulse) 6 Low Blood Pressure 7 What Your Cholesterol Levels Mean 8 Warning ...
Students will practice how to calculate their Target Heart Rate to use during exercise routines. This will help students monitor the intensity of their workouts, and ultimately help them achieve results from their workout. Standard 2: Objective 2: a,b,c Before we discuss what the Target Heart Range is and how we can us it, we must first have some basic knowledge of the heart and it's functions. Click the "habits of the heart" to learn the basics of the heart and how it circulates blood throughout the body. Habits of the Heart The hearts ...
Mr. Mike Peterson (Frazer Public School)
The purpose of this activity is to discover and learn about heart rate and the function of the heart. The students will investigate whether their hearts beat slower/faster at different times; develop an understanding of why their hearts beat slower/faster at different times; use data to develop an explanation of why their hearts beat slower/faster at different times; be aware of the effect of exercise on respiration; and be able to describe the major function of the heart.
G. Heger; B. Frey; B. Kiegler; T. Kos; G. Steurer
Clinical evidence for the presence of heart rate variability (HRV) in patients with cardiac denervation after heart transplantation raised our interest in HRV in an isolated heart preparation. Therefore hearts of seven adult white ELCO rabbits were transferred to a perfusion apparatus. After a stabilization of 30 min in the Langendorff mode, the hearts were perfused in the working heart
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.
... workout Enter your age to find a target heart rate during exercise. You'll get the most out of your activities by staying within this range of heartbeats/minute. What is your age? years. How to Check Your Heart Rate Right after you stop exercising, take your pulse: ...
Peter M. Okin; Paul Kligfield
Analysis of the rate-related change in exercise-induced ST segment depression using the exercise ST segment\\/heart rate slope and ST segment\\/heart rate index can improve the accuracy of the exercise electrocardiogram (ECG) for the identification of patients with coronary artery disease, recognition of patients with anatomically or functionally severe coronary obstruction and detection of patients at increased risk for future coronary
Surmely, Jean-François; Mohacsi, Paul; Schmid, Jean-Paul; Carrel, Thierry; Delacretaz, Etienne
A 19-year-old woman presented with decreased exercise tolerance 3 years after orthotopic heart transplantation. Exercise capacity was severely reduced, with a maximal workload of 84 W, corresponding to 56% of the predicted value. After exclusion of other causes, insufficient heart rate response to exercise was considered as the major contributor to her decreased exercise tolerance. Correction of this problem with the implantation of an AAIR pacemaker dramatically improved her physical performance, allowing her to win 5 gold medals at the European Heart and Lung Transplant Games. This case report illustrates how pacemaker therapy can dramatically improve the symptoms and performance of patients with chronotropic incompetence. PMID:16102468
Buchheit, M; Simpson, M B; Al Haddad, H; Bourdon, P C; Mendez-Villanueva, A
The aim of the present study was to verify the validity of using exercise heart rate (HRex), HR recovery (HRR) and post-exercise HR variability (HRV) during and after a submaximal running test to predict changes in physical performance over an entire competitive season in highly trained young soccer players. Sixty-five complete data sets were analyzed comparing two consecutive testing sessions (3-4 months apart) collected on 46 players (age 15.1 ± 1.5 years). Physical performance tests included a 5-min run at 9 km h(-1) followed by a seated 5-min recovery period to measure HRex, HRR and HRV, a counter movement jump, acceleration and maximal sprinting speed obtained during a 40-m sprint with 10-m splits, repeated-sprint performance and an incremental running test to estimate maximal cardiorespiratory function (end test velocity V (Vam-Eval)). Possible changes in physical performance were examined for the players presenting a substantial change in HR measures over two consecutive testing sessions (greater than 3, 13 and 10% for HRex, HRR and HRV, respectively). A decrease in HRex or increase in HRV was associated with likely improvements in V (Vam-Eval); opposite changes led to unclear changes in V (Vam-Eval). Moderate relationships were also found between individual changes in HRR and sprint [r = 0.39, 90% CL (0.07;0.64)] and repeated-sprint performance [r = -0.38 (-0.05;-0.64)]. To conclude, while monitoring HRex and HRV was effective in tracking improvements in V (Vam-Eval), changes in HRR were moderately associated with changes in (repeated-)sprint performance. The present data also question the use of HRex and HRV as systematic markers of physical performance decrements in youth soccer players. PMID:21656232
Zakynthinaki, Maria S.
The objective of the present study was to formulate a simple and at the same time effective mathematical model of heart rate kinetics in response to movement (exercise). Based on an existing model, a system of two coupled differential equations which give the rate of change of heart rate and the rate of change of exercise intensity is used. The modifications introduced to the existing model are justified and discussed in detail, while models of blood lactate accumulation in respect to time and exercise intensity are also presented. The main modification is that the proposed model has now only one parameter which reflects the overall cardiovascular condition of the individual. The time elapsed after the beginning of the exercise, the intensity of the exercise, as well as blood lactate are also taken into account. Application of the model provides information regarding the individual’s cardiovascular condition and is able to detect possible changes in it, across the data recording periods. To demonstrate examples of successful numerical fit of the model, constant intensity experimental heart rate data sets of two individuals have been selected and numerical optimization was implemented. In addition, numerical simulations provided predictions for various exercise intensities and various cardiovascular condition levels. The proposed model can serve as a powerful tool for a complete means of heart rate analysis, not only in exercise physiology (for efficiently designing training sessions for healthy subjects) but also in the areas of cardiovascular health and rehabilitation (including application in population groups for which direct heart rate recordings at intense exercises are not possible or not allowed, such as elderly or pregnant women). PMID:25876164
Mannapperuma, Kavan; Holton, Benjamin D; Lesniewski, Peter J; Thomas, John C
Imaging photoplethysmography is a relatively new technique for extracting biometric information from video images of faces. This is useful in non-invasive monitoring of patients including neonates or the aged, with respect to sudden infant death syndrome, sleep apnoea, pulmonary disease, physical or mental stress and other cardio-vascular conditions. In this paper, we investigate the limits of detection of the heart rate (HR) while reducing the video quality. We compare the performance of three independent component analysis (ICA) methods (JADE, FastICA, RADICAL), autocorrelation with signal conditioning techniques and identify the most robust approach. We discuss sources of increasing error and other limiting conditions in three situations of reduced signal-to-noise ratio: one where the area of the analyzed face is decreased from 100 to 5%, another where the face area is progressively re-sampled down to a single RGB pixel and one where the HR signal is severely reduced with respect to the boundary noise. In most cases, the cardiac pulse rate can be reliably and accurately detected from videos containing only 5% facial area or from a face occupying just 4?pixels or containing only 5% of the facial HR modulation. PMID:25501390
Hisako Tsuji; Ferdinand J. Venditti; Emily S. Manders; Jane C. Evans; Martin G. Larson; Charles L. Feldman; Daniel Levy
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
Shah, Amit J.; Su, Shaoyong; Veledar, Emir; Bremner, J. Douglas; Goldstein, Felicia C; Lampert, Rachel; Goldberg, Jack; Vaccarino, Viola
OBJECTIVE Heart rate variability (HRV), a measure of autonomic function, has been associated with cognitive function, but studies are conflicting. Previous studies have also not controlled for familial and genetic influences. METHODS We performed power spectral analysis on 24-hour ambulatory ECG’s in 416 middle-aged male twins from the Vietnam Era Twin Registry. Memory and learning were measured by verbal and visual selective reminding tests (SRT). Mixed-effect regression models were used to calculate associations between and within twin pairs, while adjusting for covariates. RESULTS The mean age (SD) was 55 (2.9) years. A statistically significant positive association was found between measures of HRV and verbal, but not visual, SRT scores. The most statistically significant unadjusted association was found between very low frequency (VLF) HRV and verbal total recall SRT, such that each logarithm of increase in VLF was associated with an increased verbal SRT score of 4.85 points (p=0.002). The association persisted despite adjustment for demographic and cardiovascular risk factors, and after accounting for familial, and genetic factors by comparing twins within pairs. A significant interaction was found between post-traumatic stress disorder (PTSD) and HRV, such that total power and ultra low frequency were associated with SRT in twins (n=362) without PTSD, but not in those with PTSD. CONCLUSION In conclusion, lower frequency spectra of HRV are associated with verbal, but not visual, learning and memory, particularly in subjects without PTSD. This association may indicate that autonomic nervous system dysregulation plays a role in cognitive decline. PMID:21715297
All About Heart Rate (Pulse) Updated:Sep 30,2014 What should you know about your heart rate? Even if you’re not an athlete, ... Where is it and what is a normal heart rate? The best places to find your pulse ...
Gent, Sabine; Kleinbongard, Petra; Dammann, Philip; Neuhäuser, Markus; Heusch, Gerd
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
... are called paroxysmal atrial tachycardia (PAT) or paroxysmal supraventricular tachycardia (PSVT). How it happens Electrical signals in the heart's upper chambers fire abnormally, which interferes ...
U. Rajendra Acharya; Paul K. Joseph; N. Kannathal; Choo Min Lim; Jasjit S. Suri
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
A large body of evidence indicates that a persistently high heart rate is associated with a significant risk for higher mortality and sudden death in individuals with a variety cardiovascu- lar disorders, as well as in the general population. Heart rates elevated beyond a certain threshold have been found to be a risk factor for mortality in patients with hypertension,
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.
Heikki V. Huikuri; Timo H. Mäkikallio
Major untoward events, such as life-threatening arrhythmias and acute coronary events, have been suggested to be triggered by the activation of the autonomic nervous system in patients with coronary artery disease. Analysis of heart rate variability by conventional time and frequency domain methods, as well as by newer methods derived from nonlinear system theory, has offered a novel approach for
The purpose of this study was to examine the effects of Ramadan fasting on body composition, aerobic exercise performance and blood lactate, heart rate and perceived exertion in regularly trained young soccer players. Sixteen male soccer players participated in this study. Mean age, stature, body mass and training age of the players were 17.4±1.2 years, 175.4±3.6 cm, 69.6±4.3 kg and 5.1±1.3 years, respectively. During the Ramadan period, all subjects voluntarily chose to follow the fasting guidelines and abstained from eating and drinking from sunrise to sunset. Body composition, hydration status, dietary intake and sleep duration were assessed on four occasions: before Ramadan, at the beginning of Ramadan, at the end of Ramadan and 2 weeks after the end of Ramadan. On each occasion, aerobic exercise performance and blood lactate, heart rate and rating of perceived exertion responses of players were also determined during an incremental running test. Repeated measures of ANOVA revealed that body mass, percentage of body fat, fat-free mass, hydration status, daily sleeping time and daily energy and macronutrient intake of players did not vary significantly throughout the study period (p>0.05). However, players experienced a small but significant decrease in skinfold thicknesses over the course of the study (p<0.05). Although ratings of perceived exertion at submaximal workloads increased during Ramadan (p<0.05), blood lactate and heart rate responses had decreased by the end of Ramadan (p<0.05). In line with these changes, peak running performance and running velocity at anaerobic threshold also improved by the end of Ramadan (p<0.05). Improvements in aerobic exercise performance with time were probably due to the effects of pre-season training program that was performed after the break of the fast (Iftar) during the month of Ramadan. The results of the present study suggest that if regular training regimen, body fluid balance, daily energy intake and sleep duration are maintained as before Ramadan, Ramadan fasting does not have detrimental effects on aerobic exercise performance or body composition in young soccer players. PMID:23486092
Laguna, P; Moody, G B; Mark, R G
This work studies the frequency behavior of a least-square method to estimate the power spectral density of unevenly sampled signals. When the uneven sampling can be modeled as uniform sampling plus a stationary random deviation, this spectrum results in a periodic repetition of the original continuous time spectrum at the mean Nyquist frequency, with a low-pass effect affecting upper frequency bands that depends on the sampling dispersion. If the dispersion is small compared with the mean sampling period, the estimation at the base band is unbiased with practically no dispersion. When uneven sampling is modeled by a deterministic sinusoidal variation respect to the uniform sampling the obtained results are in agreement with those obtained for small random deviation. This approximation is usually well satisfied in signals like heart rate (HR) series. The theoretically predicted performance has been tested and corroborated with simulated and real HR signals. The Lomb method has been compared with the classical power spectral density (PSD) estimators that include resampling to get uniform sampling. We have found that the Lomb method avoids the major problem of classical methods: the low-pass effect of the resampling. Also only frequencies up to the mean Nyquist frequency should be considered (lower than 0.5 Hz if the HR is lower than 60 bpm). We conclude that for PSD estimation of unevenly sampled signals the Lomb method is more suitable than fast Fourier transform or autoregressive estimate with linear or cubic interpolation. In extreme situations (low-HR or high-frequency components) the Lomb estimate still introduces high-frequency contamination that suggest further studies of superior performance interpolators. In the case of HR signals we have also marked the convenience of selecting a stationary heart rate period to carry out a heart rate variability analysis. PMID:9609935
Zapanta, Laurence (Laurence F.)
Heart rate variability (HRV), the beat-to-beat fluctuation of the heart rate, is a non-invasive test that measures the autonomic regulation of the heart. Assessment of HRV has been shown to predict the risk of mortality ...
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 (20%), irrespective of the training status markers and the 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
Zbilut, J.P.; Mayer-Kress, G.; Geist, K.
We discuss periodicities in the heart rate in normal and transplanted hearts. We then consider the possibility of dimensional analysis of these periodicities in transplanted hearts and problems associated with the record.
Ignico, Arlene; Corson, Arleen; Vidoni, Carla
The purpose of this project was to examine the effectiveness of a fitness infusion instructional strategy (FI) on children's activity levels and skill performance scores. This strategy included aerobic activity within the skill practice tasks and game play. In other words, students performed short bouts of activity between the practice and…
Di Rienzo, Marco; Castiglioni, Paolo; Meriggi, Paolo; Rizzo, Francesco; Trivelloni, Pierandrea; Cacopardo, Salvatore; Guadagno, Anton Giulio
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
Boomsma, Dorret I.; Plomin, Robert
Genetic and environmental influences on heart rate were studied in samples of twin pairs in middle childhood. Heart rate was measured in resting situation and under two task conditions. Heart rate was related to parental ratings of shyness, emotionality, and selective attention measure. Multivariate analysis suggested that covariance between heart…
Heart rate variability (HRV) indices based on 24-hour electrocardiograph recordings have been used in clinical research studies to assess the aggregate activity of the autonomic nervous system. While 24-hour HRV is generally considered non-invasive, use in research protocols typically involves cons...
Laborde, Sylvain; Lautenbach, Franziska; Allen, Mark S
Visual search performance under pressure is explored within the predictions of the neurovisceral integration model. The experimental aims of this study were: 1) to investigate the contribution of coping-related variables to baseline, task, and reactivity (task-baseline) high-frequency heart rate variability (HF-HRV), and 2) to investigate the contribution of coping-related variables and HF-HRV to visual search performance under pressure. Participants (n=96) completed self-report measures of coping-related variables (emotional intelligence, coping style, perceived stress intensity, perceived control of stress, coping effectiveness, challenge and threat, and attention strategy) and HF-HRV was measured during a visual search task under pressure. The data show that baseline HF-HRV was predicted by a trait coping-related variable, task HF-HRV was predicted by a combination of trait and state coping-related variables, and reactivity HF-HRV was predicted by a state coping-related variable. Visual search performance was predicted by coping-related variables but not by HF-HRV. PMID:25481358
The major focus of the present proposal was to examine psychophysiological indices that show promise for invoking different modes of automation in an adaptive automation system. With the increased use of automation in today's work environment, people's roles in the work place are being redefined from that of active participant to one of passive monitor. Although the introduction of automated systems has a number of benefits, there are also a number of disadvantages regarding worker performance. Byrne and Parasuraman have argued for the use of psychophysiological measures in the development and the implementation of adaptive automation. While performance based, model based, and psychophysiologically based adaptive automation systems have been studied, the combined use of several psychophysiological measures has never been investigated. Such a combination provides the advantage of real time evaluation of the state of the subject in two relevant dimensions and offers a more realistic approach to the implementation of adaptive automation compared to the use of either dimension by itself.
Jamie Stanley; Martin Buchheit; Jonathan M. Peake
We investigated the effect of hydrotherapy on time-trial performance and cardiac parasympathetic reactivation during recovery\\u000a from intense training. On three occasions, 18 well-trained cyclists completed 60 min high-intensity cycling, followed 20 min\\u000a later by one of three 10-min recovery interventions: passive rest (PAS), cold water immersion (CWI), or contrast water immersion\\u000a (CWT). The cyclists then rested quietly for 160 min with R–R intervals
Casuso, Rafael A; Martínez-López, Emilio; Hita-Contreras, Fidel; Ruiz-Cazalilla, Irene; Cruz-Díaz, David; Martínez-Amat, Antonio
The aim of the present study is to test the hypothesis that sprint swimming performance is enhanced by in-water passive recovery (IN) after sprint swimming bouts in well-trained adolescent swimmers. Using a randomized crossover study design, twelve well-trained adolescent swimmers performed two tests at the swimming pool after preliminary testing. They performed 5 bouts of 100m all-out swimming separated by 5 minutes of passive rest. Their individual in- or out-of-water passive recovery condition was randomized on the first day. In their second visit to the swimming pool the opposite recovery condition was indicated. More than 60% of the subjects which rested in-water were faster in the 5th bout when compared to the OUT group. However, no significant differences were found in blood lactate when IN and OUT were compared. After the first bout peak heart rate (HR peak) was lower in subsequent bouts for IN recovery when compared with OUT (p < 0.001). Thus, coaches and researchers should take into account that IN passive recovery may decrease loss of performance and diminish HR peak during sprint swimming bouts. This is particularly important given the use that many coaches give to HR as a tool in daily training. Key pointsIn-water passive recovery minimizes the loss of performance during high intensity swimmingMaximal HR is significantly reduced by in-water recoveryCoaches should take this information into account when using HR to control swimming intensityFuture research should study long-term effects induced by in-water passive recovery. PMID:25435791
... rate for selected ages. For example, the target exercise heart rate range for a 45-year-old will be ... about how hard you should exercise. • Measure your exercise heart rate in beats per minute (described above). • Look at ...
B. Mc A. SAYKRS
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
Sassi, Roberto; Signorini, Maria Gabriella; Cerutti, Sergio
In this paper, we participate to the discussion set forth by the editor of Chaos for the controversy, "Is the normal heart rate chaotic?" Our objective was to debate the question, "Is there some more appropriate term to characterize the heart rate variability (HRV) fluctuations?" We focused on the ?24 h RR series prepared for this topic and tried to verify with two different techniques, generalized structure functions and wavelet transform modulus maxima, if they might be described as being multifractal. For normal and congestive heart failure subjects, the hq exponents showed to be decreasing for increasing q with both methods, as it should be for multifractal signals. We then built 40 surrogate series to further verify such hypothesis. For most of the series (?75%-80% of cases) multifractality stood the test of the surrogate data employed. On the other hand, series coming from patients in atrial fibrillation showed a small, if any, degree of multifractality. The population analyzed is too small for definite conclusions, but the study supports the use of multifractal series to model HRV. Also it suggests that the regulatory action of autonomous nervous system might play a role in the observed multifractality.
Raija M. T. Laukkanen; Paula K. Virtanen
Heart rate is a useful indicator of physiological adaptation and intensity of effort. Therefore, heart rate monitoring is an important component of cardiovascular fitness assessment and training programmes. The electrocardiogram (ECG) and Holter monitoring devices are accurate, but they are not appropriate for use in field settings due to cost, size and complexity of operation. Lightweight telemetric heart rate monitors
H. LUCZAK; W. LAURIG
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
Teich, Malvin C.
, Grasmere, UK, 2005 #12;CONGESTIVE HEART FAILURE INABILITY OF HEART TO INCREASE CARDIAC OUTPUT IN PROPORTION #12;wav SMALLER VALUES OF wav THAN FOR NORMAL SUBJECTS HEART-FAILURE M. C. Teich, Workshop on NewHeart Rate Variability Malvin Carl Teich Boston University and Columbia University http
Jeffrey L. Goodie; Kevin T. Larkin; Scott Schauss
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
This is a task from the Illustrative Mathematics website that is one part of a complete illustration of the standard to which it is aligned. Each task has at least one solution and some commentary that addresses important asects of the task and its potential use. Here are the first few lines of the commentary for this task: Serena is starting a new workout routine and wants to keep track of her heart rate to make sure that she is exercising at the optimum level. First she ...
E. Zornik; K. Paisley; R. Nichols
Neural messengers affect Drosophila heart rate. Serotonin increases larval, pupal, and adult heart rate. Octopamine and dopamine are inactive in larva, decrease pupal rate, and increase adult heart rate. Acetylcholine and nicotine decrease larval and pupal heart rate, while acetylcholine decreases and nicotine increases adult heart rate. Muscarine decreases pupal heart rate, but is inactive in larva and adult. GABA
M. I. Lambert; Z. H. Mbambo; A. St Clair Gibson
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
Ho, Jennifer E.; Larson, Martin G.; Ghorbani, Anahita; Cheng, Susan; Coglianese, Erin E.; Vasan, Ramachandran S.; Wang, Thomas J.
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
Baker, Donald A.; Zuckerwar, Allan J.
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.
Zornik, E; Paisley, K; Nichols, R
Neural messengers affect Drosophila heart rate. Serotonin increases larval, pupal, and adult heart rate. Octopamine and dopamine are inactive in larva, decrease pupal rate, and increase adult heart rate. Acetylcholine and nicotine decrease larval and pupal heart rate, while acetylcholine decreases and nicotine increases adult heart rate. Muscarine decreases pupal heart rate, but is inactive in larva and adult. GABA is inactive in larva and adult, but decreases pupal heart rate. Glutamate is inactive in larva and pupa, but decreases adult heart rate. Proctolin decreases heart rate in all three stages. Caffeine acts only to decrease adult heart rate. PMID:10098623
Cooper, T. G.
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.
Walach, Harald; Schmidt, Stefan; Dirhold, Thomas; Nosch, Sonja
We studied the effect of suggestion and different instructions in a balanced placebo design. One hundred and fifty-nine subjects were randomized into a 2*4 factorial design. All subjects except a control group received a caffeine placebo. Subjects were randomized to a condition which was identical to an earlier study, or received an information about scientifically proven effects of caffeine (factor 1). The second factor varied instructions: subjects were either made to expect coffee, no coffee or were in a double blind condition and were told either coffee or placebo would be applied. Dependent measures were blood pressure, heart rate, well-being and a cognitive task. There was one main effect of the instruction factor (P=0.03) on diastolic blood pressure, with the group 'told caffeine' reporting significantly smaller decrease in diastolic blood pressure than controls and subjects in the double blind condition. There were no other main effects on both the instruction or suggestion factor, and no interactions. Contrary to the literature, instruction effects were very small. This was apparently due to the fact that placebo-caffeine in the dose used in this study--one cup of strong 'coffee'--did not produce expectancy effects strong enough to affect the parameters measured. It is concluded that the placebo-caffeine research paradigm is not suitable for researching instruction effects in Germany, and that reported effects should be reproduced with tighter controls. PMID:11850090
TOM EBNET; EMILY KOSINSKI; KATIE MENGES; MELISSA RICE; KAYLA RUDY
Ebnet E, Kosinski E, Menges K, Rice M, Rudy K. Predicting Maximal Heart Rate using Age, Resting Heart Rate, and Weight. Journal of Undergraduate Kinesiology Research. 2006; 2(1): 15-20. Purpose: The purpose of this study was to develop an accurate, yet concise, maximal heart rate (HRmax) prediction equation with a standard error of less than ±7 beats per minute using
Luman, Marjolein; Oosterlaan, Jaap; Hyde, Christopher; van Meel, Catharina S.; Sergeant, Joseph A.
Background: Both theoretical and clinical accounts of attention-deficit/hyperactivity disorder (ADHD) implicate a dysfunctional reinforcement system. This study investigated heart rate parameters in response to feedback associated with reward and response cost in ADHD children and controls aged 8 to 12. Methods: Heart rate responses (HRRs)…
Xiaobo Miao; Wei He; Hao Yang; Heng-Ming Tail
Heart rate variability (HRV) has become a useful tool for analyzing cardiovascular autonomic control from the electrocardiogram (ECG). Detection and analysis of HRV allows a quantitative and noninvasive method to obtain reliable and reproducible information on autonomic modulation of heart rate. Nonlinear methods (e.g., correlation dimension) are promising tools for HRV assessment. This paper presents a reliable estimation of correlation
ORAL PRESENTATION ABSTRACT Design of an Arterial Blood Pressure, Heart Rate Variability blood pressure, brachial artery, breathing rate, heart rate variability, photodiode can be used to calculate the instantaneous heart rate and consequently the heart rate variability
Wang, Qian; Zhou, GuangMin; Wang, Ying; Jiang, Qing
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
Abukonna, Ahmed; Yu, Xiaolin; Zhang, Chong; Zhang, Jianbao
The heart rate is largely under control of the autonomic nervous system. The aim of the present study is to investigate the interactions between the brain and heart underlying volitional control of the heart and to explore the effectiveness of volition as a strategy to control the heart rate without biofeedback. Twenty seven healthy male subjects voluntarily participated in the study and were instructed to decrease and increase their heart beats according to rhythmic, computer generated sound either 10% faster or slower than the subjects' measured heart rate. Sympathetic and parasympathetic activities were estimated with the heart rate variability (HRV) obtained by power spectral analysis of RR intervals. Functional coupling patterns of cerebral cortex with the heart were determined by Partial directed coherence (PDC). In HR(slow) task; HR and sympathetic activity significantly decreased. However parasympathetic activity and power spectral density of EEG in low Alpha (8-10.5 Hz) band significantly increased. Moreover information flow from parietal area (P3 and P4) to RR interval significantly increased. During HR(quick) task; HR, sympathetic activity and power spectral density of EEG in low Beta (14-24 Hz) band significantly increased. Parasympathetic activity significantly decreased. Information flow from FT8, CZ and T8 electrodes to RR interval significantly increased. Our findings suggested that the heart beat can be controlled by volition and is related to some special areas in the cortex. PMID:23810994
I. M. Schulze-Neick; H. U. Wessel; M. H. Paul
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
Soares-Caldeira, Lúcio F; de Souza, Eberton A; de Freitas, Victor H; de Moraes, Solange M F; Leicht, Anthony S; Nakamura, Fábio Y
The aim of this study was to investigate whether supplementing regular preseason futsal training with weekly sessions of repeated sprints (RS) training would have positive effects on repeated sprint ability (RSA) and field test performance. Thirteen players from a professional futsal team (22.6 ± 6.7 years, 72.8 ± 8.7 kg, 173.2 ± 6.2 cm) were divided randomly into 2 groups (AddT: n = 6 and normal training group: n = 7). Both groups performed a RSA test, Yo-Yo intermittent recovery test level 1 (YoYo IR1), squat (SJ) and countermovement jumps (CMJ), body composition, and heart rate variability (HRV) measures at rest before and after 4 weeks of preseason training. Athletes weekly stress symptoms were recorded by psychometric responses using the Daily Analysis of Life Demands for Athletes questionnaire and subjective ratings of well-being scale, respectively. The daily training load (arbitrary units) was assessed using the session of rating perceived exertion method. After the preseason training, there were no significant changes for body composition, SJ, CMJ, and RSAbest. The YoYo IR1, RSAmean, RSAworst, and RSAdecreament were significantly improved for both groups (p ? 0.05). The HRV parameters improved significantly within both groups (p ? 0.05) except for high frequency (HF, absolute and normalized units, [n.u.]), low frequency (LF) (n.u.), and the LF/HF ratio. A moderate effect size for the AddT group was observed for resting heart rate and several HRV measures. Training load and psychometric responses were similar between both groups. Additional RS training resulted in slightly greater positive changes for vagal-related HRV with similar improvements in performance and training stress during the preseason training in futsal players. PMID:24662230
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
Charles E. Riggs Jr; Dewayne J. Johnson; Barbara J. Konopka; Robert D. Kilgour
Summary The heart rate responses of physically untrained men to exercise with and without facial cooling were determined. Cold wind\\u000a (10‡ C, 6.5 m·s?1, or 2‡ C, 6.5 m·s?1) was directed at the faces of the subjects during a 16 min bout of progressively intense exercise. The 10‡ C wind resulted\\u000a in a significant (p<0.05) lowering of heart rate that appeared
Freeman, Rachel L.; Horner, Robert H.; Reichle, Joe
American Journal on Mental Retardation, 1999, Vol. 104, No. 4, 330-345 Relation Between Heart Rate and Problem Behaviors Rachel L. Freeman and Robert H. Horner University of Oregon Joe Reichle University of Minnesota A new... methodological approach for understanding self-injury, aggression, and property destruction exhibited by individuals with severe developmental disabilities was evaluated in this descriptive study. Measures of heart-rate changes before, during, and after...
C.-K. Peng; Isaac C. Henry; Joseph E. Mietus; Jeffrey M. Hausdorff; Gurucharan Khalsa; Herbert Benson; Ary L. Goldberger
Objective: This study was designed to quantify and compare the instantaneous heart rate dynamics and cardiopulmonary interactions during sequential performance of three meditation protocols with different breathing patterns. Background: We analyzed beat-to-beat heart rate and continuous breathing signals from 10 experienced meditators (4 females; 6 males; mean age 42 years; range 29–55 years) during three traditional interventions: relaxation response, breath
Schmitt, L; Fouillot, J-P; Millet, G P; Robach, P; Nicolet, G; Brugniaux, J; Richalet, J-P
We analyzed the relationship between aerobic capacities and changes in heart rate variability (HRV) in Nordic-skiers during living high-training low (Hi-Lo). Eleven skiers trained for 18 days at 1200 m, sleeping at 1200 m (LL, n = 5) or in hypoxic rooms (HL, n = 6, 3 x 6 days at altitudes of 2500 - 3000 - 3500 m, 11 h . day (-1)). Measurements were performed before, during and two weeks after Hi-Lo. VO(2max), peak power output were not improved in HL nor in LL, whereas VO(2) and power at the respiratory compensation point (VO(2RCP) and PRCP) increased by 7.5 % and 5.0 % only in HL. Significant changes in HRV occurred only in LL, in the standing position, including a 30 % (p < 0.05) increase in resting heart rate (HR), a 50 % (p < 0.05) decrease in total spectral power (TP) and a 77 % (p < 0.05) decrease in high frequency activity (HF). When all the subjects were pooled, the changes in HRV in the supine position were correlated to the changes in aerobic capacities, i.e., HF, LF and TP were correlated to VO(2RCP) and HR, HF and TP were correlated to PRCP. This study confirms the relationship between HRV and changes in aerobic capacity, therefore highlighting the potential value of HRV for monitoring altitude training adaptations. PMID:17687758
Wang, Lu; Cheng, Weiping; Sun, Zhongren; Xu, Yangyang; Cheng, Guangyu; Kuang, Haixue
This high-tech “teleacupuncture study” describes a neurovegetative ear acupressure effect in patients with chronic insomnia by using heart rate variability analysis. Heart rate (HR) and heart rate variability (HRV) measurements in 31 patients (mean age?±?SD: 54.3?±?10.6 years) were performed under standardized conditions in Harbin, China, and the data analysis was performed in Graz, Austria. Similar to our previous clinical and basic teleacupuncture research works, the electrocardiograms (ECGs) were recorded by an HRV Medilog AR12 system during ear acupressure of the Shenmen point on the left ear. HR decreased significantly (P < 0.05) during and after acupressure stimulation. The effect was not visible after the first stimulation, rather it appeared in the phase following the second acupressure stimulation (10 min after the first stimulation). Total HRV showed significant stimulation-dependent increases (P < 0.05), immediately after each acupressure stimulation with a maximum after the third stimulation (20 min after the first stimulation), but there was no long-lasting effect. The present results can serve as a solid basis for the further investigations of auricular point stimulation for noninvasive complementary use in treating insomnia. PMID:23476702
McLeod, K; Hillis, W; Houston, A; Wilson, N; Trainer, A; Neilson, J; Doig, W
OBJECTIVE—To examine autonomic function as assessed by heart rate variability in patients 10 or more years after repair of tetralogy of Fallot, and to relate this to cardiac structure, function, and electrocardiographic indices.?METHODS—Heart rate variability was measured by standard time domain techniques on a 24 hour Holter ECG in 28 patients, aged 12 to 34 years (mean 19.5), who had undergone repair of tetralogy of Fallot at least 10 years previously. Echocardiography was performed to assess left ventricular size and function, right ventricular size and pressure, and any proximal pulmonary arterial stenosis. Right ventricular function was evaluated by radionuclide scan. QRS duration, QT interval, and QT dispersion were measured on a standard 12 lead ECG. Measurements of heart rate variability were compared with values from 28 age matched healthy controls (mean age 19.9 years). Interrelations between variables were assessed using Pearson correlation coefficients and stepwise regression analysis.?RESULTS—Heart rate variability was reduced, compared with values for age matched normal controls, in 12 of the 28 patients. Reduced heart rate variability was associated with increased age, increased right ventricular size and pressure, and widening of the QRS complex.?CONCLUSIONS—Reduced heart rate variability is a feature following repair of tetralogy of Fallot. It is associated with increasing age, impaired right ventricular haemodynamics, and widening of the QRS complex. Under these circumstances, reduced heart rate variability may be a marker for deteriorating right ventricular function. Increased QRS duration has been identified as a risk factor for sudden death following repair of tetralogy of Fallot, and impaired cardiac autonomic control may be one of the mechanisms involved.???Keywords: tetralogy of Fallot; heart rate variability; right ventricular function; congenital heart disease PMID:10336928
Weippert, Matthias; Behrens, Kristin; Rieger, Annika; Stoll, Regina; Kreuzfeld, Steffi
Aim was to elucidate autonomic responses to dynamic and static (isometric) exercise of the lower limbs eliciting the same moderate heart rate (HR) response. Method: 23 males performed two kinds of voluntary exercise in a supine position at similar heart rates: static exercise (SE) of the lower limbs (static leg press) and dynamic exercise (DE) of the lower limbs (cycling). Subjective effort, systolic (SBP) and diastolic blood pressure (DBP), mean arterial pressure (MAP), rate pressure product (RPP) and the time between consecutive heart beats (RR-intervals) were measured. Time-domain (SDNN, RMSSD), frequency-domain (power in the low and high frequency band (LFP, HFP)) and geometric measures (SD1, SD2) as well as non-linear measures of regularity (approximate entropy (ApEn), sample entropy (SampEn) and correlation dimension D2) were calculated. Results: Although HR was similar during both exercise conditions (88±10 bpm), subjective effort, SBP, DBP, MAP and RPP were significantly enhanced during SE. HRV indicators representing overall variability (SDNN, SD 2) and vagal modulated variability (RMSSD, HFP, SD 1) were increased. LFP, thought to be modulated by both autonomic branches, tended to be higher during SE. ApEn and SampEn were decreased whereas D2 was enhanced during SE. It can be concluded that autonomic control processes during SE and DE were qualitatively different despite similar heart rate levels. The differences were reflected by blood pressure and HRV indices. HRV-measures indicated a stronger vagal cardiac activity during SE, while blood pressure response indicated a stronger sympathetic efferent activity to the vessels. The elevated vagal cardiac activity during SE might be a response mechanism, compensating a possible co-activation of sympathetic cardiac efferents, as HR and LF/HF was similar and LFP tended to be higher. However, this conclusion must be drawn cautiously as there is no HRV-marker reflecting “pure” sympathetic cardiac activity. PMID:24349546
Baska-Vincze, Boglárka; Baska, Ferenc; Szenci, Ottó
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
Pildner von Steinburg, Stephanie; Boulesteix, Anne-Laure; Lederer, Christian; Grunow, Stefani; Schiermeier, Sven; Hatzmann, Wolfgang; Schneider, Karl-Theodor M.
Aim. There is no consensus about the normal fetal heart rate. Current international guidelines recommend for the normal fetal heart rate (FHR) baseline different ranges of 110 to 150 beats per minute (bpm) or 110 to 160 bpm. We started with a precise definition of “normality” and performed a retrospective computerized analysis of electronically recorded FHR tracings. Methods. We analyzed all recorded cardiotocography tracings of singleton pregnancies in three German medical centers from 2000 to 2007 and identified 78,852 tracings of sufficient quality. For each tracing, the baseline FHR was extracted by eliminating accelerations/decelerations and averaging based on the “delayed moving windows” algorithm. After analyzing 40% of the dataset as “training set” from one hospital generating a hypothetical normal baseline range, evaluation of external validity on the other 60% of the data was performed using data from later years in the same hospital and externally using data from the two other hospitals. Results. Based on the training data set, the “best” FHR range was 115 or 120 to 160 bpm. Validation in all three data sets identified 120 to 160 bpm as the correct symmetric “normal range”. FHR decreases slightly during gestation. Conclusions. Normal ranges for FHR are 120 to 160 bpm. Many international guidelines define ranges of 110 to 160 bpm which seem to be safe in daily practice. However, further studies should confirm that such asymmetric alarm limits are safe, with a particular focus on the lower bound, and should give insights about how to show and further improve the usefulness of the widely used practice of CTG monitoring. PMID:23761161
Bair, Christine Caldwell
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
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.
ORIGINAL ARTICLE Instantaneous changes in heart rate regulation due to mental load in simulated bands (LF 0.040.15 Hz; HF 0.150.4 Hz), in addition to the traditional linear heart rate variability) performed twice, each followed by a rest condition. The heart rate and measures related to vagal modulation
Stone, Michael H.; And Others
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…
Stamps, Leighton E.; Porges, Stephen W.
Trace conditioning was evaluated in newborn infants by measurements of heart rate responses to a conditioned stimulus in anticipation of or in absence of the unconditioned stimulus. Data suggest females have higher levels of heart rate variability than males, which parallels their greater conditionability. (GO)
Ho, David; Zhao, Xin; Gao, Shumin; Hong, Chull; Vatner, Dorothy E.; Vatner, Stephen F.
The majority of current cardiovascular research involves studies in genetically engineered mouse models. The measurement of heart rate is central to understanding cardiovascular control under normal conditions, with altered autonomic tone, superimposed stress or disease states, both in wild type mice as well as those with altered genes. Electrocardiography (ECG) is the “gold standard” using either hard wire or telemetry transmission. In addition, heart rate is measured or monitored from the frequency of the arterial pressure pulse or cardiac contraction, or by pulse oximetry. For each of these techniques, discussions of materials and methods, as well as advantages and limitations are covered. However, only the direct ECG monitoring will determine not only the precise heart rates but also whether the cardiac rhythm is normal or not. PMID:21743842
Teich, Malvin C.
MULTIRESOLUTION WAVELET ANALYSIS OF HEART RATE VARIABILITY FOR HEART-FAILURE AND HEART- viation OW,V(m) is found to be superior to two commonly used heart-rate-variability me~ures for diagnosing a study on a collection of elec- - irocardiograms from patients who suffer from conges- tive heart failure
Yunfeng Sun; Yinling Zhang; Ning He; Xufeng Liu; Danmin Miao
Caffeine placebo expectation seems to improve vigilance and cognitive performance. This study investigated the effect of caffeine and placebo expectation on vigilance and cognitive performance during 28 h sleep deprivation. Ten healthy males volunteered to take part in the double-blind, cross-over study, which required participants to complete five treatment periods of 28 h separated by 1-week wash-out intervals. The treatments
Zugck, C; Martinka, P; Stöckl, G; Tschöpe, C; Störk, S
Background | Elevated resting heart rate is associated with increased morbidity and mortality in patients with chronic systolic heart failure (CHF). Lowering of heart rate improves cardiovascular outcome in these patients. Therefore, heart rate reduction is an important element of therapeutic management and consistently reflected in current European guidelines for heart failure. Methods | The INDICATE study was initiated as a multicenter nationwide cross-sectional survey aiming to analyze the current quality of care in outpatients with CHF (documented left ventricular systolic dysfunction) in Germany. 20 consecutive patients were to be included in the survey from February until June 2012 by 793 cardiologic private practices. Detailed documentation of each patient was performed using a standardized questionnaire. Results | CHF was known for more than 6 months in 88?% of the 15?148 included patients. Mean heart rate in the study population was 73?±?13?min(-1). In 42?% of patients the heart rate was???75?min(-1). 86?% were treated with betablockers. However, higher doses of betablockers were not associated with lower resting heart rate. 27?% of patients remained on heart rates???75?min(-1) although receiving at least 50?% of betablocker target dose. Conclusion | INDICATE reveals a considerable proportion of outpatients with CHF showing an elevated heart rate despite beta blockade - irrespective of applied dose. These results emphasize the importance of optimizing the pharmacological management of resting heart rate according to guidelines in these patients. PMID:25734683
Byrd, Dana L.; Reuther, Erin T.; McNamara, Joseph P. H.; DeLucca, Teri L.; Berg, William K.
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.
Paolo Melillo; Roberta Fusco; Mario Sansone; Marcello Bracale; Leandro Pecchia
The aim of this study was to investigate the discrimination power of standard long-term heart rate variability (HRV) measures\\u000a for the diagnosis of chronic heart failure (CHF). The authors performed a retrospective analysis on four public Holter databases,\\u000a analyzing the data of 72 normal subjects and 44 patients suffering from CHF. To assess the discrimination power of HRV measures,\\u000a an
Multiscale Complexity Analysis of Heart Rate Dynamics in Heart Failure: Preliminary Findings from with congestive heart failure (CHF) enrolled in the MUSIC study. Our hypothe- sis is that the heart rate time of CHF. 1. Introduction The development of new markers of mortality risk in congestive heart failure (CHF
Kirkpatrick, Beth; Birnbaum, Burton H.
Learning about the relationship between heart rate and physical activity is an important aspect of fitness education. Use of a heart rate monitor (HRM) helps a student to understand how stretching and large muscle movements gradually increase the heart rate and blood flow, and enables students to measure their exercise heart rates and set goals…
Carvalho, JoĂŁo Luiz
- dividuals with congestive heart failure. The HRV computational tools mentioned above do not imple- mentMATLAB SOFTWARE FOR DETRENDED FLUCTUATION ANALYSIS OF HEART RATE VARIABILITY Fernanda S. Leite1, Heart rate variability, HRV. Abstract: The analysis of heart rate variability (HRV) is an important tool
K. Sh. Nadareishvili; I. I. Meskhishvili; D. D. Kakhiani; G. L. Ormotsadze; G. T. Nazarishvili; M. G. Gvasalia; M. T. Khvedelidze; V. Ya. Sandodze
Temporal and spectral parameters of heart rate variability were studied as criteria for classification of mature Chinchilla rabbit population according to their basal neurovegetative status. The absolute values of total spectral power density and individual frequency bands differed significantly in vagotonics and sympathotonics. However, standardized spectral power distributions in high-, low- and very low-frequency ranges were similar in both groups.
Costa, Tommaso; Boccignone, Giuseppe; Ferraro, Mario
Heart rate variability (HRV) is an important measure of sympathetic and parasympathetic functions of the autonomic nervous system and a key indicator of cardiovascular condition. This paper proposes a novel method to investigate HRV, namely by modelling it as a linear combination of Gaussians. Results show that three Gaussians are enough to describe the stationary statistics of heart variability and to provide a straightforward interpretation of the HRV power spectrum. Comparisons have been made also with synthetic data generated from different physiologically based models showing the plausibility of the Gaussian mixture parameters. PMID:22666386
Jones, Catherine L.; Minati, Ludovico; Nagai, Yoko; Medford, Nick; Harrison, Neil A.; Gray, Marcus; Ward, Jamie; Critchley, Hugo D.
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.
YOSHIDA, Masumi; ONDA, Ken; WADA, Yasunori; KUWAHARA, Masayoshi
Parameters of heart rate variability would explain changes in heart rate during the disease status in cows and to evaluate whether such changes might provide a more sensitive and quantitative indicator of these conditions than crude indices. For this purpose, we recorded electrocardiograms for 24 hr using a Holter-type electrocardiograph and applied power spectral analysis of heart rate variability in both five clinically healthy and four hospitalized cows. The significant findings of the current investigation were that the diurnal variations of autonomic nervous function are abolished in cows that are sick. This abnormal rhythm was induced by predominant parasympathetic inhibition in these cows. Therefore, the heart rate variability may be a useful indicator of sickness condition in cows. PMID:25648088
Escher, J; Evéquoz, D
The effect of trophotropic (relaxing) music on heart rate and heart rate variability has been investigated in 23 healthy young individuals by means of 24-hour Holter-ECG. Relaxing music (Bach, Vivaldi, Mozart) resulted in significant reduction of heart rate and also significant reduction of heart rate variability. The significance of these results for the use of music in coronary heart disease is discussed. PMID:10412282
Cristina Giannattasio; Antonio Vincenti; Monica Failla; Anna Capra; Antonio Cirň; Sergio De Ceglia; Gaetano Gentile; Roberta Brambilla; Giuseppe Mancia
In rats, an increase in heart rate by pacing is accompanied by progressive large-artery stiffening. Whether this is also the case in humans is unknown. We enrolled 20 patients who were chronically implanted with a pacemaker because of atrioventricular block or sick sinus syndrome. Arterial distensibility was measured by an echo-tracking device. In 10 patients, the evaluation was performed on
D Rastenyt?; J Tuomilehto; V Moltchanov; J Lindström; P Pietinen; A Nissinen
The present study investigated the association between 24-h urinary sodium excretion and heart rate in the determination of blood pressure (BP) levels in a large random population sample from eastern Finland. Three independent risk factor surveys were performed in 1979, 1982 and 1987 using the same methodology. Data from each survey was pooled for subjects aged 25–64 years who reported
Curt A. Sandman; Thomas R. McCanne; Donald N. Kaiser; Bruce Diamond
26 undergraduates were tested with a tachistoscopic recognition task while heart rate (HR) and several other autonomic indexes were monitored. In Exp I, HR was employed as an independent variable, and stimulus presentation was contingent upon the presence of individually determined low, middle, and high HRs. Results indicate that low HR facilitated performance especially for stimuli presented at the fastest
James B. Carter; Eric W. Banister; Andrew P. Blaber
Long-term endurance training significantly influences how the autonomic nervous system controls heart function. Endurance training increases parasym- pathetic activity and decreases sympathetic activity in the human heart at rest. These two training-induced autonomic effects, coupled with a possible reduction in intrinsic heart rate, decrease resting heart rate. Long-term endurance training also decreases submaximal exercise heart rate by reducing sympathetic activity
Billman, George E.
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
Paris-Sud XI, Université de
Analysis of Heart Rate Variability Using Time-Varying Filtering of Heart Transplanted Patients the heart rate variability (HRV), obtained by using the time-varying integral pulse frequency modulation (TVIPFM) which is well adapted to the exercise stress testing. We consider that the mean heart period
Schönbom, Hanno; Kassens, Ana; Hopster-Iversen, Charlotte; Klewitz, Jutta; Piechotta, Marion; Martinsson, Gunilla; Kißler, Andreas; Burger, Dominik; Sieme, Harald
Pregnancy diagnostics in equine reproduction are routinely performed using transrectal ultrasonography, although it is also possible to visualize the fetus by transabdominal ultrasound examinations from the 90th day of gestation onward. We hypothesized that ultrasound examinations may stress the mare and that the gestational stage status and lactation may influence the mare's stress reaction. To investigate the stress reaction, 25 thoroughbred mares of different age, pregnancy and lactational status underwent a transrectal examination. In pregnant mares, an additional transabdominal examination was performed. Salivary cortisol concentration, mean heart rate, and heart rate variability of mares were assessed to evaluate the reactions of hypothalamic-pituitary-adrenal (HPA) axis and of the autonomic nervous system. Significant differences were observed between lactating and nonlactating mares; with a lower responsiveness to stress in lactating mares. The transrectal ultrasound examination in nonlactating mares induced a significant increase in salivary cortisol (P < 0.05), and in the heart rate variability parameter, ratio of low to high frequencies (P < 0.05). This reflects an activation of the HPA axis and a shift to more sympathetic dominance. In contrast, a transabdominally performed pregnancy check did not induce an activation of the HPA axis over basal level but increased the mean heart rate and low to high frequency ratio. The results of this study indicate that checks of advanced pregnancies can be easily performed by transabdominal ultrasonography. With regard to animal welfare, this technique should be preferred during midgestation in nonlactating mares. PMID:25529317
STUART BRODY; RAGNAR PREUT
We examined the relationship between recalled and diary recorded frequency of penile-vaginal intercourse (FSI) and both resting heart rate variability (HRV; an index of cardiac autonomic control and parasympathetic tone associated with cardiovascular health outcomes) and resting diastolic blood pressure (DBP) in 120 healthy adults aged 19-38 (subjects scoring above the 87th percentile on the Lie scale of the Eysenck
Gianfranco Piccirillo; Maria Rita Munizzi; Filippo L. Fimognari; Vincenzo Marigliano
Hypertension is often associated with findings of sympathetic hyperactivity. Evidence shows that adrenergic receptor stimulation can induce left ventricular hypertrophy. Using an autoregressive algorithm in a power spectrum analysis of heart-rate variability in 14 subjects with mild hypertension (mean age 41 ± 9.0 years) and 9 age-matched normotensives we compared autonomic nervous system function at baseline (rest) and during sympathetic
J. Kurths; A. Voss; P. Saparin; A. Witt; H. J. Kleiner; N. Wessel
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
Hirofumi Tanaka; Kevin D Monahan; Douglas R Seals
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
Amaral, L. A.; Goldberger, A. L.; Stanley, H. E.
We consider the question of how the cardiac rhythm spontaneously self-regulates and propose a new mechanism as a possible answer. We model the neuroautonomic regulation of the heart rate as a stochastic feedback system and find that the model successfully accounts for key characteristics of cardiac variability, including the 1/f power spectrum, the functional form and scaling of the distribution of variations of the interbeat intervals, and the correlations in the Fourier phases which indicate nonlinear dynamics.
Václav Bunc; Jan Heller; Jirí Leso
In order to describe the kinetics of the reaction of the heart rate (HR) to the onset of exercise of constant intensity, the half?time (t1\\/2) of HR can be used. First in a study of exercise of intensity corresponding to 2 W kg on a cycle ergometer, the t1\\/2 in 15 trained male rowers and 11 untrained male students was
Ballas, S.; Gitstein, S.; Kharasch, J.
Umbilical cord haematoma is an infrequent condition associated with high perinatal and fetal mortality and morbidity. This report describes a rare case of umbilical cord haematoma associated with loss of fetal beat to beat variation during labour. The infant exhibited mild asphyxia only. Previous publications are reviewed and fetal heart rate changes associated with umbilical cord haematoma are discussed. Images Figure 2 Figure 3 PMID:4034467
Jerry M. Malkiewicz
The present study was concerned with certain individual differences that relate to a subject’s ability to increase his heart rate on command when given appropriate external feedback. The main purpose was to extend to the operant conditioning paradigm Eysenck’s theory that introverts classically condition more readily than extraverts. A second purpose was to determine which personality factors—extraversion, anxiety, and ability
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
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
Shaffer, Fred; McCraty, Rollin; Zerr, Christopher L
Heart rate variability (HRV), the change in the time intervals between adjacent heartbeats, is an emergent property of interdependent regulatory systems that operate on different time scales to adapt to challenges and achieve optimal performance. This article briefly reviews neural regulation of the heart, and its basic anatomy, the cardiac cycle, and the sinoatrial and atrioventricular pacemakers. The cardiovascular regulation center in the medulla integrates sensory information and input from higher brain centers, and afferent cardiovascular system inputs to adjust heart rate and blood pressure via sympathetic and parasympathetic efferent pathways. This article reviews sympathetic and parasympathetic influences on the heart, and examines the interpretation of HRV and the association between reduced HRV, risk of disease and mortality, and the loss of regulatory capacity. This article also discusses the intrinsic cardiac nervous system and the heart-brain connection, through which afferent information can influence activity in the subcortical and frontocortical areas, and motor cortex. It also considers new perspectives on the putative underlying physiological mechanisms and properties of the ultra-low-frequency (ULF), very-low-frequency (VLF), low-frequency (LF), and high-frequency (HF) bands. Additionally, it reviews the most common time and frequency domain measurements as well as standardized data collection protocols. In its final section, this article integrates Porges' polyvagal theory, Thayer and colleagues' neurovisceral integration model, Lehrer et al.'s resonance frequency model, and the Institute of HeartMath's coherence model. The authors conclude that a coherent heart is not a metronome because its rhythms are characterized by both complexity and stability over longer time scales. Future research should expand understanding of how the heart and its intrinsic nervous system influence the brain. PMID:25324790
Shaffer, Fred; McCraty, Rollin; Zerr, Christopher L.
Heart rate variability (HRV), the change in the time intervals between adjacent heartbeats, is an emergent property of interdependent regulatory systems that operate on different time scales to adapt to challenges and achieve optimal performance. This article briefly reviews neural regulation of the heart, and its basic anatomy, the cardiac cycle, and the sinoatrial and atrioventricular pacemakers. The cardiovascular regulation center in the medulla integrates sensory information and input from higher brain centers, and afferent cardiovascular system inputs to adjust heart rate and blood pressure via sympathetic and parasympathetic efferent pathways. This article reviews sympathetic and parasympathetic influences on the heart, and examines the interpretation of HRV and the association between reduced HRV, risk of disease and mortality, and the loss of regulatory capacity. This article also discusses the intrinsic cardiac nervous system and the heart-brain connection, through which afferent information can influence activity in the subcortical and frontocortical areas, and motor cortex. It also considers new perspectives on the putative underlying physiological mechanisms and properties of the ultra-low-frequency (ULF), very-low-frequency (VLF), low-frequency (LF), and high-frequency (HF) bands. Additionally, it reviews the most common time and frequency domain measurements as well as standardized data collection protocols. In its final section, this article integrates Porges' polyvagal theory, Thayer and colleagues' neurovisceral integration model, Lehrer et al.'s resonance frequency model, and the Institute of HeartMath's coherence model. The authors conclude that a coherent heart is not a metronome because its rhythms are characterized by both complexity and stability over longer time scales. Future research should expand understanding of how the heart and its intrinsic nervous system influence the brain. PMID:25324790
Kenji Sunagawa; Toru Kawada; Tsutomu Nakahara
Summary Although the characteristics of the static interactions between the sympathetic and parasympathetic nervous systems in regulating heart rate have been well established, how the dynamic interaction modulates the heart rate response remains unknown. Thus, we investigated the dynamic interaction by estimating the transfer function from nerve stimulation to heart rate, using band-limited Gaussian white noise, in anesthetized rabbits. Concomitant
Olufsen, Mette Sofie
with 17 parameters. The model uses blood pressure data as input topredict the heart rate whileORIGINAL 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
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
Development of Heart Rate Circadian Rhythm in Chickens K. Moriyaa *, R. Akiyamab , E.M. Dzialowskic, University of North Texas, Denton, Texas, USA ABSTRACT In chick embryos, various instantaneous heart rate of mean heart rate (MHR) have been elucidated. IHR changes have also measured in newly hatched and young
Teddy M. Cheng; Andrey V. Savkin; Steven W. Su; Branko G. Celler; Lu Wang
In this study, a control design is proposed for the tracking control of heart rate response during treadmill exercise. The controller tracks an exerciser's heart rate to a given heart rate profile, that may represent a prescribed exercise protocol, by varying the speed of the treadmill. A guaranteed cost control approach is adopted in the control design so that the
Pasing, Stephanie; von Lewinski, Mareike; Wulf, Manuela; Erber, Regina; Aurich, Christine
The aim of this study was to evaluate the stress response of stallions (n = 16) aged 3-13 years with previous sexual experience to semen collection by determination of heart rate, heart rate variability, and cortisol in saliva. Recordings were done on two consecutive days. The time intervals from leaving the box until arrival in the collection barn and from first exposure to the teaser mare until ejaculation as well as the number of mounts until ejaculation were neither affected by collection day nor by age, sexual experience (i.e., the number of breeding seasons the stallion experienced), or sexual workload of the stallion (i.e., the mean number of semen collections per week). Heart rate was continuously determined from 30 minutes before to 30 minutes after ejaculation and significantly increased in response to the semen collection procedure (P < 0.001). Changes in heart rate were significantly influenced by sexual experience (P < 0.01) and sexual workload (P < 0.05) but not by the age of the stallions. Day of semen collection did not have any effects. The heart rate variability variable root mean square of successive RR differences was not affected by semen collection procedures. Cortisol concentration in saliva was determined from 60 minutes before to 120 minutes after ejaculation and did not change significantly. The results indicate that semen collection is perceived as not more than a modest temporary stressor in sexually experienced and well-trained stallions. PMID:23664794
Jones, Peter; Ovenden, Nick; Dauger, Stéphane; Peters, Mark J.
Purpose Reductions in heart rate occur frequently in children during critical care intubation and are currently considered the gold standard for haemodynamic instability. Our objective was to estimate loss of heart beats during intubation and compare this to reduction in heart rate alone whilst testing the impact of atropine pre-medication. Methods Data were extracted from a prospective 2-year cohort study of intubation ECGs from critically ill children in PICU/Paediatric Transport. A three step algorithm was established to exclude variation in pre-intubation heart rate (using a 95%CI limit derived from pre-intubation heart rate variation of the children included), measure the heart rate over time and finally the estimate the numbers of lost beats. Results 333 intubations in children were eligible for inclusion of which 245 were available for analysis (74%). Intubations where the fall in heart rate was less than 50 bpm were accompanied almost exclusively by less than 25 lost beats (n?=?175, median 0 [0–1]). When there was a reduction of >50 bpm there was a poor correlation with numbers of lost beats (n?=?70, median 42 [15–83]). During intubation the median number of lost beats was 8 – when atropine was not used compared to 0 [0–0] when atropine was used (p<0.001). Conclusions A reduction in heart rate during intubation of <50 bpm reliably predicted a minimal loss of beats. When the reduction in heart rate was >50 bpm the heart rate was poorly predictive of lost beats. A study looking at the relationship between lost beats and cardiac output needs to be performed. Atropine reduces both fall in heart rate and loss of beats. Similar area-under-the-curve methodology may be useful for estimating risk when biological parameters deviate outside normal range. PMID:24503645
Lars Lind; Bertil Andrén
Objective We investigated the associations between heart rate recovery after exercise (as a suggested measure of vagal activity), heart rate variability, and measurements of the insulin resistance syndrome. Material and Methods Seventy men aged 70 years were examined with a symptom-limited bicycle exercise test, a 24-hour heart rate variability test, and different measurements of different components of the insulin resistance
Paris-Sud XI, UniversitĂ© de
collagen accumulation in rats with congestive heart failure induced by permanent coronary artery ligationEur Heart J . Author manuscript Page /1 11 Chronic heart rate reduction with ivabradine improves systolic function of the reperfused heart through a dual mechanism involving a direct mechanical effect
Vandeput, Steven; Widjaja, Devy; Aubert, Andre E.; Van Huffel, Sabine
Background Spaceflight causes changes in the cardiovascular control system. The aim of this study was to evaluate postflight recovery of linear and nonlinear neural markers of heart rate modulation, with a special focus on day-night variations. Material/Methods Twenty-four-hour Holter ECG recordings were obtained in 8 astronauts participating in space missions aboard the International Space Station (ISS). Data recording was performed 1 month before launch, and 5 and 30 days after return to Earth from short- and long-term flights. Cardiovascular control was inferred from linear and nonlinear heart rate variability (HRV) parameters, separately during 2-hour day and 2-hour night recordings. Results No remarkable differences were found in the postflight recovery between astronauts from short- and long-duration spaceflights. Five days after return to Earth, vagal modulation was significantly decreased compared to the preflight condition (day: p=0.001; night: p=0.019), while the sympathovagal balance was strongly increased, but only at night (p=0.017). A few nonlinear parameters were reduced early postflight compared to preflight values, but these were not always statistically significant. No significant differences remained after 30 days of postflight recovery. Conclusions Our results show that 5 days after return from both short- and long-duration space missions, neural mechanisms of heart rate regulation are still disturbed. After 1 month, autonomic control of heart rate recovered almost completely. PMID:23291736
Oweis, Rami J; As'ad, Hala; Aldarawsheh, Amany; Al-Khdeirat, Rawan; Lwissy, Kaldoun
Safe monitoring of foetal heart rate is a valuable tool for the healthy evolution and wellbeing of both foetus and mother. This paper presents a non-invasive optical technique that allows for foetal heart rate detection using a photovoltaic infrared (IR) detector placed on the mother's abdomen. The system presented here consists of a photoplethysmography (PPG) circuit, abdomen circuit and a personal computer equipped with MATLAB. A near IR beam having a wavelength of 880?nm is transmitted through the mother's abdomen and foetal tissue. The received abdominal signal that conveys information pertaining to the mother and foetal heart rate is sensed by a low noise photodetector. The PC receives the signal through the National Instrumentation Data Acquisition Card (NIDAQ). After synchronous detection of the abdominal and finger PPG signals, the designed MATLAB-based software saves, analyses and extracts information related to the foetal heart rate. Extraction is carried out using recursive least squares adaptive filtration. Measurements on eight pregnant women with gestational periods ranging from 35-39 weeks were performed using the proposed system and CTG. Results show a correlation coefficient of 0.978 and a correlation confidence interval between 88-99.6%. The t test results in a p value of 0.034, which is less than 0.05. Low power, low cost, high signal-to-noise ratio, reduction of ambient light effect and ease of use are the main characteristics of the proposed system. PMID:24195701
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.
Michael R. Esco; Michele S. Olson; Henry N. Williford; Daniel L. Blessing; David Shannon; Peter Grandjean
Objective There is limited research available regarding a possible relationship between resting heart rate variability (HRV) and post-exercise\\u000a heart rate recovery (HRR). The aim of this study was to examine the relationship between resting HRV and HRR after maximal\\u000a exercise.\\u000a \\u000a \\u000a \\u000a Methods Sixty-six college age men participated in this study. HRV was measured in a supine position before and for 30 min after a
Williams, Joan; McCauley, Joyce; Grumble, Melissa
How the heart works is found in "A Framework for K-12 Science Education" and connects to Life Sciences Core and Component Ideas, From Molecules to Organisms: Structures and Processes (NRC 2012). By the end of grade 2, students should understand that all organisms have external parts, which they use in various ways to seek, find, and take…
Sharpley, Christopher F.; And Others
Investigated effects of 3 routine classroom arithmetic and reading tasks upon the heart rate reactivity of 30 fifth grade children. Results indicated that some children showed large increases in heart rates during the three tasks, and that these children should be considered at risk for coronary heart disease. (Author/TE)
Fei, L.; Keeling, P. J.; Gill, J. S.; Bashir, Y.; Statters, D. J.; Poloniecki, J.; McKenna, W. J.; Camm, A. J.
BACKGROUND--It has been shown that heart rate variability is decreased in patients with congestive heart failure and that depressed heart rate variability is associated with a propensity to ventricular arrhythmias. Little is known, however, about heart rate variability in patients with both congestive heart failure and ventricular arrhythmias. METHODS--Spectral heart rate variability was analysed from 24 hour ambulatory electrocardiograms in 15 controls, 15 patients with non-sustained ventricular tachycardia associated with clinically normal hearts (NHVT group), and 40 patients with congestive heart failure (CHF group) secondary to either ischaemic heart disease (n = 15) or idiopathic dilated cardiomyopathy (n = 25). Of the 40 patients with congestive heart failure 15 had no appreciable ventricular arrhythmias (ventricular extrasystoles < 10 beats/h and no salvos) and formed the CHF-VA- group. Another 15 patients with congestive heart failure and non-sustained ventricular tachycardia formed the CHF-NSVT group. RESULTS--Heart rate variability was significantly lower in the CHF group than in controls (mean (SD) total frequency 23 (12) v 43 (13) ms; low frequency 12 (8) v 28 (9) ms; high frequency 8 (5) v 14 (7) ms; p < 0.001). The differences in heart rate variability between controls and the NHVT group, between ischaemic heart disease and dilated cardiomyopathy, and between the CHF-VA- and CHF-NSVT groups were not significant. In the CHF group heart rate variability was significantly related to left ventricular ejection fraction but not associated with ventricular arrhythmias. The frequency of ventricular extrasystoles was significantly related to the high frequency component of heart rate variability (r = 0.54, p < 0.05) in the NHVT group. Stepwise multiple regression analysis showed that in the CHF group, heart rate variability was predominantly related to left ventricular ejection fraction (p < 0.05). There was no significant difference in heart rate variability between survivors (n = 34) and those who died suddenly (n = 6) at one year of follow up in the CHF group. CONCLUSION--In patients with congestive heart failure, heart rate variability is significantly decreased. The depressed heart rate variability is principally related to the degree of left ventricular impairment and is independent of aetiology and the presence of ventricular arrhythmias. The data suggest that analysis of heart rate variability does not help the identification of patients with congestive heart failure at increased risk of sudden death. PMID:8198881
Brody, Stuart; Preut, Ragnar
We examined the relationship between recalled and diary recorded frequency of penile-vaginal intercourse (FSI) and both resting heart rate variability (HRV; an index of cardiac autonomic control and parasympathetic tone associated with cardiovascular health outcomes) and resting diastolic blood pressure (DBP) in 120 healthy adults aged 19-38 (subjects scoring above the 87th percentile on the Lie scale of the Eysenck Personality Inventory were excluded from analyses). As in a previous smaller study, greater HRV was associated with greater FSI (but not masturbation or non-coital sex with a partner) and rated importance of intercourse. There were no sex differences in the HRV-FSI relationship, and the relationship was not explained by including measures of Extraversion, Neuroticism, Depression, Trait Anxiety, or partnership satisfaction. However, the previously obtained negative association of FSI with DBP was not replicated. PMID:14504008
B Andersson; J Wikstrand; T Ljung; S Björk; Ĺ Wennmalm; P Björntorp; Björn Andersson
OBJECTIVE: The aim of this work was to examine the relationship between cardiac autonomic function and urinary albumin excretion in obesity.SUBJECTS: These were 27 obese non-diabetic postmenopausal women and 18 non-obese healthy postmenopausal women.MEASUREMENTS: Urinary albumin excretion as well as plasma nitrate, both indices of capillary function, were measured. Power spectral analysis of heart rate variability was performed, as a
Denise Felber Dietrich; Joel Schwartz; Christian Schindler; Jean-Michel Gaspoz; Jean-Claude Barthelemy; Jean-Marie Tschopp; Frederic Roche; Arnold von Eckardstein; Otto Brandli; Philippe Leuenberger; Diane R Gold; Ursula Ackermann-Liebrich
Background Exposure to environmental tobacco smoke (ETS) has been shown to increase the risk for cardiovascular diseases and death, and autonomic dysfunction (specifically, reduced heart rate variability (HRV)) is a predictor of increased cardiac risk. This study tests the hypothesis that ETS exposure reduces HRV in the general population and discusses possible pathways. Methods This cross-sectional study was conducted between
Graff, G.; Graff, B.; Kaczkowska, A.; Makowiec, D.; Amigó, J. M.; Piskorski, J.; Narkiewicz, K.; Guzik, P.
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.
Hani Al Haddad; Paul B. Laursen; Didier Chollet; Frédéric Lemaitre; Saďd Ahmaidi; Martin Buchheit
This study aimed to investigate the effect of cold and thermoneutral water immersion on post-exercise parasympathetic reactivation, inferred from heart rate (HR) recovery (HRR) and HR variability (HRV) indices. Twelve men performed, on three separate occasions, an intermittent exercise bout (all-out 30-s Wingate test, 5min seated recovery, followed by 5min of submaximal running exercise), randomly followed by 5min of passive
Paul E. Fenster; Keith A. Comess; Christine Dahl Hanson
The heart rate and blood pressure response to exercise are clinically important parameters evaluated during treadmill testing. These responses may be altered by cardiac drugs. We evaluated the effect of procainamide and disopyramide on the heart rate and blood pressure response to treadmill exercise in 9 healthy volunteers. Each subject performed one Bruce protocol treadmill test while on each of
Crone, Eveline A.; Jennings, J. Richard; Van der Molen, Maurits W.
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…
Rodríguez-Lińares, L; Lado, M J; Vila, X A; Méndez, A J; Cuesta, P
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
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
Muirhead, R. J.; Puff, R. D.
We propose a simple Bayesian method for the classification of time series signals originating from mutually exclusive sources. In particular, the method is used to address the question of whether a 24-h recording of human heart rate data is produced by a normally functioning heart or by one exhibiting symptoms of congestive heart failure. Our method correctly classifies 18 of 18 normal heart data sets, and 38 of 44 congestive failure data sets.
Yi-Da Tang; Thomas A. Dewland; Detlef Wencker; Stuart D. Katz
BackgroundPost-exercise heart rate recovery (HRR) is an index of parasympathetic function associated with clinical outcomes in populations with and without documented coronary heart disease. Decreased parasympathetic activity is thought to be associated with disease progression in chronic heart failure (HF), but an independent association between post-exercise HRR and clinical outcomes among such patients has not been established.
Peter U; Axel W. Frey; Alexandra Fuchs; Christina Paniara; Helmut Roskamm; Markus Schwaiger; Bruno Reichart
Several investigators have shown signs of possible sympathetic but not parasympathetic reinnervation in heart transplanted patients. Spectral analysis of heart rate and blood pressure variability is a noninvasive tool appropriate to detect a functional autonomous reinnervation to the heart. In a follow-up study, 13 patients after heart transplantation (HTx) were investigated, mean age 50.698.5 years, 18 healthy volunteers were selected
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…
Hemant Ishwaran; Eugene H. Blackstone; Claire E. Pothier; Michael S. Lauer
Recent studies have confirmed heart rate fall after treadmill exercise testing, or heart rate recovery, as a powerful predictor of mortality from heart disease. Heart rate recovery depends on central reactivation of vagal tone and decreased vagal activity is a risk factor for death. If heart rate recovery is defined as the fall in heart rate after 1 minute following
Monfredi, Oliver; Lyashkov, Alexey E; Johnsen, Anne-Berit; Inada, Shin; Schneider, Heiko; Wang, Ruoxi; Nirmalan, Mahesh; Wisloff, Ulrik; Maltsev, Victor A; Lakatta, Edward G; Zhang, Henggui; Boyett, Mark R
Heart rate (HR) variability (HRV; beat-to-beat changes in the R-wave to R-wave interval) has attracted considerable attention during the past 30+ years (PubMed currently lists >17 000 publications). Clinically, a decrease in HRV is correlated to higher morbidity and mortality in diverse conditions, from heart disease to fetal distress. It is usually attributed to fluctuation in cardiac autonomic nerve activity. We calculated HRV parameters from a variety of cardiac preparations (including humans, living animals, Langendorff-perfused heart, and single sinoatrial nodal cell) in diverse species, combining this with data from previously published articles. We show that regardless of conditions, there is a universal exponential decay-like relationship between HRV and HR. Using 2 biophysical models, we develop a theory for this and confirm that HRV is primarily dependent on HR and cannot be used in any simple way to assess autonomic nerve activity to the heart. We suggest that the correlation between a change in HRV and altered morbidity and mortality is substantially attributable to the concurrent change in HR. This calls for re-evaluation of the findings from many articles that have not adjusted properly or at all for HR differences when comparing HRV in multiple circumstances. PMID:25225208
Guo, Ping; Sun, Weixin; Jin, Jie; Zhao, Qingping; Chen, Xiang; Kong, Shu; Huang, Yizhuo
Focusing on the heart rate control mode of acceleration sensor based rate responsive pacemakers, this paper implemented the design of activity--heart rate prediction system. Bluetooth module was used as communication means in activity--heart rate prediction system, and the slave computer was used to complete the acceleration signal acquisition and processing, map from acceleration signal to the pacing rate signal, and achieve real-time transmission of acceleration signal and heart rate signal. The master computer fulfilled real-time display and recording of acceleration signal and heart rate signal, moreover, it achieved control function to the slave computer algorithm through classification of 6 parameters. The results of verification experiment showed that there was a significant relation between mapping heart rate and actual heart rate using linear mapping algorithm (R2 = 0.787, P < 0.001). PMID:22242376
Katalin Maros; Antal Dóka; Ádám Miklósi
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
Technical Note Brain correlates of autonomic modulation: Combining heart rate variability with f-gated fMRI timeseries with continuous- time heart rate variability (HRV) to estimate central autonomic pro reserved. Keywords: HF; HRV; Cardiovagal; Exercise; Handgrip Introduction The autonomic nervous system (ANS
C. Arden Pope; Richard L. Verrier; Eric G. Lovett; Andrew C. Larson; Mark E. Raizenne; Richard E. Kanner; Joel Schwartz; G. Martin Villegas; Diane R. Gold; Douglas W. Dockery
Background: Epidemiologic studies have linked fine particulate air pollution with cardiopulmonary mortality, yet underlying biologic mechanisms remain unknown. Changes in heart rate variability (HRV) may reflect changes in cardiac autonomic function and risk of sudden cardiac death. This study evaluated changes in mean heart rate and HRV in human beings associated with changes in exposure to particulate air pollution. Methods:
M. Strupler; G Mueller; C. Perret
OBJECTIVE: To find the individual intensity for aerobic endurance training, the lactate minimum test (LMT) seems to be a promising method. LMTs described in the literature consist of speed or work rate-based protocols, but for training prescription in daily practice mostly heart rate is used. The aim of the present study was to investigate the reproducibility of a new heart
Gilbert, Jennie A.
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…
Ernst H. Jager
Formulas are presented which establish a meaningful interrelationship between blood pressure and heart rate during exericse, describing both of them as functions of one variable and a set of common parameters, namely, a quantity interpreted as a no-load effort, and the rest values of heart rate and of systolic and diastolic blood pressure. The formulas can be used, in the
Malena Ivarsson; Martin Anderson; Torbjörn Ĺkerstedt; Frank Lindblad
Objective: To investigate how playing a violent\\/nonviolent television game during the evening affects sympathetic and parasympathetic reactions during and after playing as well as sleep quality during the night after playing. Subjects and Methods: In total, 19 boys, 12-15 years of age, played television games on two occasions in their homes and participated once without gaming. Heart rate, heart rate
Londeree, Ben R.; Moeschberger, Melvin L.
To reduce confusion regarding reported effects of age on maximal exercise heart rate, a comprehensive review of the relevant English literature was conducted. Data on maximal heart rate after exercising with a bicycle, a treadmill, and after swimming were analyzed with regard to physical fitness and to age, sex, and racial differences. (Authors/PP)
C.-K Peng; Joseph E Mietus; Yanhui Liu; Gurucharan Khalsa; Pamela S Douglas; Herbert Benson; Ary L Goldberger
We report extremely prominent heart rate oscillations associated with slow breathing during specific traditional forms of Chinese Chi and Kundalini Yoga meditation techniques in healthy young adults. We applied both spectral analysis and a novel analytic technique based on the Hilbert transform to quantify these heart rate dynamics. The amplitude of these oscillations during meditation was significantly greater than in
Valerie A. MacIntyre; Peter D. MacIntyre; Geoff Carre
This study examines the relations among the perception of speaking anxiety and difficulties in emotion regulation with 2 measures of physiological activity: heart rate (HR) and heart rate variability (HRV). Results show significant changes in HR and state anxiety, but not HRV, among the 6 experimental conditions: quiet, reading in both sitting and standing positions, and speaking in both sitting
A. H. Beg; Noraziah Ahmad; Nawsher Khan; Ahmed N Abd Alla; Muhammad Nubli; A. K. Lovely
This research proposes a new artificial intelligence strategy to enhance software games based on heart rate variability. The model consists of two modules (visual learning and IQ test) that will conjoined with a biofeedback device connected to a computer to monitor student heart rate and record its changes in a stressful situation and generate appropriate reports. By playing these two
Jenni Anttonen; Veikko Surakka
New methods for unobtrusive monitoring of computer users' emotion psychophysiology are very much needed in human-computer interaction research. The present aim was to study heart rate changes during emotionally provocative stimulation. Six-second long auditory, visual, and audiovisual emotionally negative, neutral, and positive stimuli were presented to 24 participants. Heart rate responses were measured with a regular office chair embedded with
Godinez, Angelica; Ayzenberg, Ruthie; Liston, Dorian B.; Stone, Leland S.
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).
Gilbert, F F; Gofton, N
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
Paris-Sud XI, Université de
Chronic heart rate reduction with ivabradine improves systolic function of the reperfused firstname.lastname@example.org inserm-00500900,version1-12Jul2010 Author manuscript, published in "European heart journal 2010 function and calcium handling to chronic heart rate reduction with ivabradine in the reperfused heart
Saleh, M. A.; Winget, C. M.
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.
Dawes, Derek Shawn
the effects on heart rate and oxygen saturation of transitioning from positive pressure breathing for increased Gz load to positive pressure breathing for altitude. Analysis was performed on previously recorded data taken with permission from Brooks United...
Lehrer, Paul M.; Gevirtz, Richard
In recent years there has been substantial support for heart rate variability biofeedback (HRVB) as a treatment for a variety of disorders and for performance enhancement (Gevirtz, 2013). Since conditions as widely varied as asthma and depression seem to respond to this form of cardiorespiratory feedback training, the issue of possible mechanisms becomes more salient. The most supported possible mechanism is the strengthening of homeostasis in the baroreceptor (Vaschillo et al., 2002; Lehrer et al., 2003). Recently, the effect on the vagal afferent pathway to the frontal cortical areas has been proposed. In this article, we review these and other possible mechanisms that might explain the positive effects of HRVB. PMID:25101026
Sunagawa, K; Kawada, T; Nakahara, T
Although the characteristics of the static interactions between the sympathetic and parasympathetic nervous systems in regulating heart rate have been well established, how the dynamic interaction modulates the heart rate response remains unknown. Thus, we investigated the dynamic interaction by estimating the transfer function from nerve stimulation to heart rate, using band-limited Gaussian white noise, in anesthetized rabbits. Concomitant tonic vagal stimulation at 5 and 10 Hz increased the gain of the transfer function relating dynamic sympathetic stimulation to heart rate by 55.0%+/-40.1% and 80.7%+/-50.5%, respectively (P < 0.05). Concomitant tonic sympathetic stimulation at 5 and 10 Hz increased the gain of the transfer function relating dynamic vagal stimulation to heart rate by 18.2%+/-17.9% and 24.1%+/-18.0%, respectively (P < 0.05). Such bidirectional augmentation was also observed during simultaneous dynamic stimulation of the sympathetic and vagal nerves independent of their stimulation patterns. Because of these characteristics, changes in sympathetic or vagal tone alone can alter the dynamic heart rate response to stimulation of the other nerve. We explained this phenomenon by assuming a sigmoidal static relationship between autonomic nerve activity and heart rate. To confirm this assumption, we identified the static and dynamic characteristics of heart rate regulation by a neural network analysis, using large-amplitude Gaussian white noise input. To examine the mechanism involved in the bidirectional augmentation, we increased cytosolic adenosine 3',5'-cyclic monophosphate (cAMP) at the postjunctional effector site by applying pharmacological interventions. The cAMP accumulation increased the gain of the transfer function relating dynamic vagal stimulation to heart rate. Thus, accumulation of cAMP contributes, at least in part, to the sympathetic augmentation of the dynamic vagal control of heart rate. PMID:10442397
Alex Sagie; Martin G. Larson; Robert J. Goldberg; James R. Bengtson; Daniel Levy
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
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 ˇ 0.001). This was accompanied by an increase in mean arterial blood pressure (84 ± 6 to 93 ± 6 mmHg; p ˇ 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 ˇ 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.
... Your health care provider will review the electronic recording of the baby’s heartbeat (called the fetal heart ... form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without prior written permission from the ...
Sae Young Jae; Kevin S. Heffernan; Miyoung Lee; Bo Fernhall
Purpose Heart rate recovery (HRR) after treadmill exercise testing is an index of cardiac autonomic activity in non-disabled persons,\\u000a but it is unknown if this is also the case in individuals with spinal cord injury (SCI). We investigated the relationship\\u000a between HRR after maximal arm exercise testing and resting autonomic activity in persons with paraplegia.\\u000a \\u000a \\u000a \\u000a \\u000a Methods A total of 17 (male n = 9,
Du, Wei-Guo; Ye, Hua; Zhao, Bo; Warner, Daniel A.; Shine, Richard
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
Billman, George E.
Heart rate variability (HRV), the beat-to-beat variation in either heart rate (HR) or heart period (R-R interval), has become a popular clinical and investigational tool to quantify cardiac autonomic regulation. However, it is not widely appreciated that, due to the inverse curvilinear relationship between HR and R-R interval, HR per se can profoundly influence HRV. It is, therefore, critical to correct HRV for the prevailing HR particularly, as HR changes in response to autonomic neural activation or inhibition. The present study evaluated the effects of HR on the HRV response to autonomic interventions that either increased (submaximal exercise, n = 25 or baroreceptor reflex activation, n = 20) or reduced (pharmacological blockade: ?-adrenergic receptor, muscarinic receptor antagonists alone and in combination, n = 25, or bilateral cervical vagotomy, n = 9) autonomic neural activity in a canine model. Both total (RR interval standard deviation, RRSD) and the high frequency (HF) variability (HF, 0.24–1.04 Hz) were determined before and in response to an autonomic intervention. All interventions that reduced or abolished cardiac parasympathetic regulation provoked large reductions in HRV even after HR correction [division by mean RRsec or (mean RRsec)2 for RRSD and HF, respectively] while interventions that reduced HR yielded mixed results. ?-adrenergic receptor blockade reduced HRV (RRSD but not HF) while both RRSD and HF increased in response to increases in arterial blood (baroreceptor reflex activation) even after HR correction. These data suggest that the physiological basis for HRV is revealed after correction for prevailing HR and, further, that cardiac parasympathetic activity is responsible for a major portion of the HRV in the dog. PMID:23986716
L. Ceri Davies; Darrel P Francis; Piotr Ponikowski; Massimo F Piepoli; Andrew J. S Coats
Reduced heart rate variability (HRV) and attenuated baroreflex sensitivity (BS) after myocardial infarction and in patients with chronic congestive heart failure (CHF) are associated with poor prognosis. Recent studies have shown that a large proportion of the prognostic power from HRV measurements is localized in heart rate turbulence immediately after ventricular premature complexes. The mechanism of heart rate turbulence remains
A simple one-dimensional Langevin-type stochastic difference equation can simulate the heart-rate fluctuations in a time scale from minutes to hours. The model consists of a deterministic nonlinear part and a stochastic part typical of Gaussian noise, and both parts can be directly determined from measured heart-rate data. Data from healthy subjects typically exhibit the deterministic part with two or more stable fixed points. Studies of 15 congestive heart-failure subjects reveal that the deterministic part of pathologic heart dynamics has no clear stable fixed points. Direct simulations of the stochastic model for normal and pathologic cases can produce statistical parameters similar to those of real subjects. Results directly indicate that pathologic situations simplify the heart-rate control system.
Nicholas L Mills; Alexander E Finlayson; Manuel C Gonzalez; Hĺkan Törnqvist; Stefan Barath; Elen Vink; Colin Goudie; Jeremy P Langrish; Stefan Söderberg; Nicholas A Boon; Keith A A Fox; Ken Donaldson; Thomas Sandström; Anders Blomberg; David E Newby
ObjectiveExposure to air pollution is associated with increases in cardiovascular morbidity and mortality. This study was undertaken to determine the effect of diesel exhaust inhalation on heart rhythm and heart rate variability in healthy volunteers and patients with coronary heart disease.Design and settingDouble-blind randomised crossover studies in a university teaching hospital.Patients32 healthy non-smoking volunteers and 20 patients with prior myocardial
Kiyono, Ken; Struzik, Zbigniew R.; Aoyagi, Naoko; Togo, Fumiharu; Yamamoto, Yoshiharu
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.
J. Mokrý; T. Reme?ová; K. Javorka
Mokr? J, T. RemeŔová, K. Javorka: Changes in Respiratory Rate, Blood Pressure and Heart Rate Variability in Rabbits during Orthostasis. Acta Vet. Brno 2006, 75: 3-12. The purpose of the study was to evaluate the changes of respiratory rate, systemic blood pressure and heart rate variability parameters (HRV) during orthostasis in anaesthetized rabbits. Furthermore, these changes were influenced by affecting
Philippe Lechat; Jean-Sébastien Hulot; A Mallet
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
Swain, U G; Gilbert, F F; Robinette, J D
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
Pretlow, Robert A., III; Stoughton, John W.
Research and development is presented of real time signal processing methodologies for the detection of fetal heart tones within a noise-contaminated signal from a passive acoustic sensor. A linear predictor algorithm is utilized for detection of the heart tone event and additional processing derives heart rate. The linear predictor is adaptively 'trained' in a least mean square error sense on generic fetal heart tones recorded from patients. A real time monitor system is described which outputs to a strip chart recorder for plotting the time history of the fetal heart rate. The system is validated in the context of the fetal nonstress test. Comparisons are made with ultrasonic nonstress tests on a series of patients. Comparative data provides favorable indications of the feasibility of the acoustic monitor for clinical use.
Beaudin, Paula; And Others
It was concluded that playing squash is an activity that results in heart rate responses of sufficient intensity to elicit aerobic training effects without producing high lactic acid concentration in the blood. (MM)
Teich, M C; Jost, B M; Vibe-Rheymer, K; Heneghan, C; Teich, Malvin C.; Lowen, Steven B.; Jost, Bradley M.; Vibe-Rheymer, Karin; Heneghan, Conor
We focus on various measures of the fluctuations of the sequence of intervals between beats of the human heart, and how such fluctuations can be used to assess the presence or likelihood of cardiovascular disease. We examine sixteen such measures and their suitability for correctly classifying heartbeat records of various lengths as normal or revealing the presence of cardiac dysfunction, particularly congestive heart failure. Using receiver-operating-characteristic analysis we demonstrate that scale-dependent measures prove substantially superior to scale-independent ones. The wavelet-transform standard deviation at a scale near 32 heartbeat intervals, and its spectral counterpart near 1/32 cycles/interval, turn out to provide reliable results using heartbeat records just minutes long. We further establish for all subjects that the human heartbeat has an underlying stochastic origin rather than arising from a chaotic attractor. Finally, we develop a mathematical point process that emulates the human heartbea...
Jan C. De Munck; Sonia I. Goncalves; Theo J. C. Faes; Petra J. W. Pouwels; Joost P. A. Kuijer; Rob M. Heethaar; Fernando Henrique Lopes Da Silva
The brain's resting state is studied with the analysis of co-registered fMRI\\/EEG\\/ECG. In particular, it was investigated whether spontaneous heart rate fluctuations are correlated to fMRI-signals. This might be the case because of a direct hemodynamic coupling, or due to an indirect coupling between heart rate and alpha band power, which are both hall marks of the resting state. It
Vikram K. Yeragani
Symptoms of anxiety suggest autonomic dysfunction and most of the psycho-tropic agents used to treat anxiety and affective disorders have strong autonomic effects. This article describes the utility and importance of analysis of heart rate and blood pressure time series to study cardiac autonomic function in psychiatric research. The variability of heart rate between 0.15 and 0.5 Hz is related
K. T. Francis; P. R. McClatchey; J. R. Sumsion; D. E. Hansen
Summary Recent studies have demonstrated there is a definitive deflection in the heart rate response to incremental velocity work\\u000a that coincides with the anaerobic threshold. These studies were conducted with elite athletes who performed the specific activities\\u000a in which they were trained. The purpose of this study was to determine if the same relationship in heart rate and ventilatory\\u000a response to
Hooker, John C.
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.
Ryan, S. M.; Goldberger, A. L.; Pincus, S. M.; Mietus, J.; Lipsitz, L. A.
OBJECTIVES. This study aimed to quantify the complex dynamics of beat-to-beat sinus rhythm heart rate fluctuations and to determine their differences as a function of gender and age. BACKGROUND. Recently, measures of heart rate variability and the nonlinear "complexity" of heart rate dynamics have been used as indicators of cardiovascular health. Because women have lower cardiovascular risk and greater longevity than men, we postulated that there are important gender-related differences in beat-to-beat heart rate dynamics. METHODS. We analyzed heart rate dynamics during 8-min segments of continuous electrocardiographic recording in healthy young (20 to 39 years old), middle-aged (40 to 64 years old) and elderly (65 to 90 years old) men (n = 40) and women (n = 27) while they performed spontaneous and metronomic (15 breaths/min) breathing. Relatively high (0.15 to 0.40 Hz) and low (0.01 to 0.15 Hz) frequency components of heart rate variability were computed using spectral analysis. The overall "complexity" of each heart rate time series was quantified by its approximate entropy, a measure of regularity derived from nonlinear dynamics ("chaos" theory). RESULTS. Mean heart rate did not differ between the age groups or genders. High frequency heart rate power and the high/low frequency power ratio decreased with age in both men and women (p < 0.05). The high/low frequency power ratio during spontaneous and metronomic breathing was greater in women than men (p < 0.05). Heart rate approximate entropy decreased with age and was higher in women than men (p < 0.05). CONCLUSIONS. High frequency heart rate spectral power (associated with parasympathetic activity) and the overall complexity of heart rate dynamics are higher in women than men. These complementary findings indicate the need to account for gender-as well as age-related differences in heart rate dynamics. Whether these gender differences are related to lower cardiovascular disease risk and greater longevity in women requires further study.
Moore, A. D. Jr; Lee, S. M.; Greenisen, M. C.; Bishop, P.
Accurate heart rate measurement during work is required for many industrial hygiene and ergonomics situations. The purpose of this investigation was to determine the validity of heart rate measurements obtained by a simple, lightweight, commercially available wrist-worn heart rate monitor (HRM) during work (cycle exercise) sessions conducted in the laboratory and also during the particularly challenging work environment of space flight. Three different comparisons were made. The first compared HRM data to simultaneous electrocardiogram (ECG) recordings of varying heart rates that were generated by an ECG simulator. The second compared HRM data to ECG recordings collected during work sessions of 14 subjects in the laboratory. Finally, ECG downlink and HRM data were compared in four astronauts who performed cycle exercise during space flight. The data were analyzed using regression techniques. The results were that the HRM recorded virtually identical heart rates compared with ECG recordings for the data set generated by an ECG simulator. The regression equation for the relationship between ECG versus HRM heart rate data during work in the laboratory was: ECG HR = 0.99 x (HRM) + 0.82 (r2 = 0.99). Finally, the agreement between ECG downlink data and HRM data during space flight was also very high, with the regression equation being: Downlink ECG HR = 1.05 x (HRM) -5.71 (r2 = 0.99). The results of this study indicate that the HRM provides accurate data and may be used to reliably obtain valid data regarding heart rate responses during work.
Yum, Myung-Kul; Kim, Kyung-Sik; Kim, June-Soo
Introduction: We aim to test our hypothesis that, during daily activity, though not as prominent as during HUT test, the patients may show different degree of intermittency in heart rates compared to healthy persons. METHOD AND RESULTS: Thirty patients with neurocardiogenic syncope who showed a positive HUT test and thirty healthy controls without history of syncope were included. Their twenty-four hour ambulatory electrocardiograms were digitized and RR interval (RRI) data of six-hour interval were analyzed. To quantify the intermittency (C1) behavior, The intermittency analysis was performed using Mexican hat wavelet. For the syncope group, the values of C1 were significantly higher at 6AM-6PM and lower at 6AM-midnight, respectively. However, the values were not different at midnight-6AM. The significant night-day circadian change shown in the control group was lost in C1. CONCLUSION: When compared to healthy control, the patients with neurocardiogenic syncope shows increased intermittency of heart rates in daytime during daily activity, and abnormal circadian rhythms of the index. These new findings may be useful for investigating the pathophysiology of neurocardiogenic syncope and early identification of the patients.
Di Rienzo, M; Parati, G; Rizzo, F; Meriggi, P; Merati, G; Faini, A; Castiglioni, P
On the basis of indirect evidences it has been hypothesized that during space missions the almost complete absence of gravity might impair the baroreflex control of circulation. In the first part of this paper we report results obtained from a series of experiments carried out to directly verify this hypothesis during the 16-day STS 107 Shuttle flight. Spontaneous baroreflex sensitivity was assessed in four astronauts before flight (baseline) and at days 0-1, 6-7 and 12-13 during flight, both at rest and while performing moderate exercise. Our results indicate that at rest the baroreflex sensitivity significantly increased in the early flight phase, as compared to pre-flight values and tended to return to baseline in the mid-late phase of flight. During exercise, baroreflex sensitivity was lower than at rest, without any difference among pre-flight and in-flight values. These findings seem to exclude the hypothesis of an impairment of the baroreflex control of heart rate during exposure to microgravity, at least over a time window of 16 days. In the second part of the paper we propose a novel textile-based methodology for heart rate and other vital signs monitoring during gravity stress. The positive results obtained from its use during parachute jumps support the use of smart garments for the unobtrusive assessment of physiological parameters in extreme environments. PMID:18003559
Mullen, T. J.; Berger, R. D.; Oman, C. M.; Cohen, R. J.
In a study of 18 human subjects, we applied a new technique, estimation of the transfer function between instantaneous lung volume (ILV) and instantaneous heart rate (HR), to assess autonomic activity during motion sickness. Two control recordings of ILV and electrocardiogram (ECG) were made prior to the development of motion sickness. During the first, subjects were seated motionless, and during the second they were seated rotating sinusoidally about an earth vertical axis. Subjects then wore prism goggles that reverse the left-right visual field and performed manual tasks until they developed moderate motion sickness. Finally, ILV and ECG were recorded while subjects maintained a relatively constant level of sickness by intermittent eye closure during rotation with the goggles. Based on analyses of ILV to HR transfer functions from the three conditions, we were unable to demonstrate a change in autonomic control of heart rate due to rotation alone or due to motion sickness. These findings do not support the notion that moderate motion sickness is manifested as a generalized autonomic response.
Malvin C. Teich; Steven B. Lowen; Bradley M. Jost; Karin Vibe-Rheymer; Conor Heneghan
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.
Sarlis, N. V.; Skordas, E. S.; Varotsos, P. A.
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.
Arzeno, Natalia M. (Natalia María Arzeno Soltero)
This thesis examines two challenging problems in chaos analysis: distinguishing deterministic chaos and stochastic (noise-induced) chaos, and applying chaotic heart rate variability (HRV) analysis to the prognosis of ...
de Alencar, Maria Clara Noman; Rocha, Manoel Otávio da Costa; Lima, Márcia Maria de Oliveira; Costa, Henrique Silveira; Sousa, Giovane Rodrigo; Carneiro, Renata de Carvalho Bicalho; Silva, Guilherme Canabrava Rodrigues; Brandăo, Fernando Vieira; Kreuser, Lucas Jordan; Ribeiro, Antonio Luiz Pinho; Nunes, Maria Carmo Pereira
Background Chagas disease patients with right bundle-branch block (RBBB) have diverse clinical presentation and prognosis, depending on left ventricular (LV) function. Autonomic disorder can be an early marker of heart involvement. The heart rate recovery (HRR) after exercise may identify autonomic dysfunction, with impact on therapeutic strategies. This study was designed to assess the HRR after symptom-limited exercise testing in asymptomatic Chagas disease patients with RBBB without ventricular dysfunction compared to patients with indeterminate form of Chagas disease and healthy controls. Methods One hundred and forty-nine subjects divided into 3 groups were included. A control group was comprised of healthy individuals; group 1 included patients in the indeterminate form of Chagas disease; and group 2 included patients with complete RBBB with or without left anterior hemiblock, and normal ventricular systolic function. A symptom-limited exercise test was performed and heart rate (HR) response to exercise was assessed. HRR was defined as the difference between HR at peak exercise and 1 min following test termination. Results There were no differences in heart-rate profile during exercise between healthy individuals and patients in indeterminate form, whereas patients with RBBB had more prevalence of chronotropic incompetence, lower exercise capacity and lower HRR compared with patients in indeterminate form and controls. A delayed decrease in the HR after exercise was found in 17 patients (15%), 9% in indeterminate form and 24% with RBBB, associated with older age, worse functional capacity, impaired chronotropic response, and ventricular arrhythmias during both exercise and recovery. By multivariable analysis, the independent predictors of a delayed decrease in the HRR were age (odds ratio [OR] 1.11; 95% confidence interval [CI] 1.03 to 1.21; p?=?0.010) and presence of RBBB (OR 3.97; 95% CI 1.05 to 15.01; p?=?0.042). Conclusions A small proportion (15%) of asymptomatic Chagas patients had attenuated HRR after exercise, being more prevalent in patients with RBBB compared with patients in indeterminate form and controls. PMID:24979699
An, Sang Min; Park, Jong Suk; Kim, Sang Ho
[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
Struzik, Zbigniew R.; Hayano, Junichiro; Sakata, Seiichiro; Kwak, Shin; Yamamoto, Yoshiharu
We present systematic evidence for the origins of 1/f -type temporal scaling in human heart rate. The heart rate is regulated by the activity of two branches of the autonomic nervous system: the parasympathetic (PNS) and the sympathetic (SNS) nervous systems. We examine alterations in the scaling property when the balance between PNS and SNS activity is modified, and find that the relative PNS suppression by congestive heart failure results in a substantial increase in the Hurst exponent H towards random-walk scaling 1/f2 and a similar breakdown is observed with relative SNS suppression by primary autonomic failure. These results suggest that 1/f scaling in heart rate requires the intricate balance between the antagonistic activity of PNS and SNS.
Mirka Hintsanen; Marko Elovainio; Sampsa Puttonen; Mika Kivimäki; Tuomas Koskinen; Olli T. Raitakari; Liisa Keltikangas-Järvinen
Background: Work stress indicated by effort—reward imbalance is hypothesized to cause autonomic arousal, which, if prolonged\\u000a or frequent, could contribute to cardiovascular pathology. However, only limited empirical evidence on this mechanism is available.\\u000a Purpose: This study examined associations between effort-reward imbalance, heart rate (HR), and heart rate variability (HRV).\\u000a Method: The participants were 457 women and 406 men (mean age
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)
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.
Georgieva, A. E.; Payne, S. J.; Moulden, M.; Redman, C. W. G.
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°) and `modified' Positive Predictive Value (PPV°) 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.
Conder, Robert L.; Conder, Alanna A.
The study of heart rate variability (HRV) has emerged as an essential component of cardiovascular health, as well as a physiological mechanism by which one can increase the interactive communication between the cardiac and the neurocognitive systems (i.e., the body and the brain). It is well-established that lack of HRV implies cardiopathology, morbidity, reduced quality-of-life, and precipitous mortality. On the positive, optimal HRV has been associated with good cardiovascular health, autonomic nervous system (ANS) control, emotional regulation, and enhanced neurocognitive processing. In addition to health benefits, optimal HRV has been shown to improve neurocognitive performance by enhancing focus, visual acuity and readiness, and by promoting emotional regulation needed for peak performance. In concussed athletes and soldiers, concussions not only alter brain connectivity, but also alter cardiac functioning and impair cardiovascular performance upon exertion. Altered sympathetic and parasympathetic balance in the ANS has been postulated as a critical factor in refractory post concussive syndrome (PCS). This article will review both the pathological aspects of reduced HRV on athletic performance, as well as the cardiovascular and cerebrovascular components of concussion and PCS. Additionally, this article will review interventions with HRV biofeedback (HRV BFB) training as a promising and underutilized treatment for sports and military-related concussion. Finally, this article will review research and promising case studies pertaining to use of HRV BFB for enhancement of cognition and performance, with applicability to concussion rehabilitation. PMID:25165461
Conder, Robert L; Conder, Alanna A
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
A body of evidence indicates that subjects with tachycardia are more likely to develop hypertension (1–3) and atherosclerosis in future years (4–6). However, the connection between heart rate and cardiovascular risk has long been neglected on the grounds that tachycardia\\u000a is often associated with the traditional risk factors for atherosclerosis, such as hypertension or metabolic abnormalities\\u000a (7). A high heart
van Leeuwen, P.; Cysarz, D.; Lange, S.; Geue, D.; Groenemeyer, D.
Fetal heart rate complexity was examined on the basis of RR interval time series obtained in the second and third trimester of pregnancy. In each fetal RR interval time series, short term beat-to-beat heart rate changes were coded in 8bit binary sequences. Redundancies of the 28 different binary patterns were reduced by two different procedures. The complexity of these sequences was quantified using the approximate entropy (ApEn), resulting in discrete ApEn values which were used for classifying the sequences into 17 pattern sets. Also, the sequences were grouped into 20 pattern classes with respect to identity after rotation or inversion of the binary value. There was a specific, nonuniform distribution of the sequences in the pattern sets and this differed from the distribution found in surrogate data. In the course of gestation, the number of sequences increased in seven pattern sets, decreased in four and remained unchanged in six. Sequences that occurred less often over time, both regular and irregular, were characterized by patterns reflecting frequent beat-to-beat reversals in heart rate. They were also predominant in the surrogate data, suggesting that these patterns are associated with stochastic heart beat trains. Sequences that occurred more frequently over time were relatively rare in the surrogate data. Some of these sequences had a high degree of regularity and corresponded to prolonged heart rate accelerations or decelerations which may be associated with directed fetal activity or movement or baroreflex activity. Application of the pattern classes revealed that those sequences with a high degree of irregularity correspond to heart rate patterns resulting from complex physiological activity such as fetal breathing movements. The results suggest that the development of the autonomic nervous system and the emergence of fetal behavioral states lead to increases in not only irregular but also regular heart rate patterns. Using symbolic dynamics to examine the cardiovascular system may thus lead to new insight with respect to fetal development.
Nichols, Randall; Davis, Kathryn L.; McCord, Tim; Schmidt, Dave; Slezak, Alex M.
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…
Platisa, Mirjana M; Gal, Vera
The aim of this study was to examine the dependence of heart rate variability (HRV) measures on RR interval length and to find out relationships between linear and nonlinear measures. The spectral powers in very low (VLF), low (LF) and high (HF) frequency regions, short-term scaling exponent alpha(1) and sample entropy (SampEn) were determined. All spectral powers increased with increasing RR interval length until they reached a plateau. Neighbouring spectral powers were strongly correlated. The largest fraction of the spectrum consisted of VLF (from about 40 to 95%) and the smallest of HF, although HF was most sensitive to changes in RR interval length. SampEn is also increased with increasing RR interval, reaching a plateau. The dependence of alpha(1) on RR showed a deflection point at 0.5 s. Nonlinear measures can be expressed by spectral powers: alpha(1) by a linear function of ln(LF/HF) and SampEn by a quadratic function of ln HF. We concluded that during the day an increase of HR up to 120 beats min(-1) was reflected in a reduction in HF and LF and to a smaller extent in VLF and by decreased complexity and increased correlation in RR interval series. In sleep, HRV measures are at a plateau. We suggest that below intrinsic value, HR is regulated mainly by changes of parasympathetic activity, reflected in linear and nonlinear HRV measures. PMID:16400201
A. D. Gething; L. Passfield; B. Davies
This study investigated the relationship between the intensity of an inspiratory muscle training programme and its effect on respiratory muscle strength, exercising heart rate, and ratings of perceived exertion. A total of 66 subjects were randomly assigned to one of three groups. One group trained at 100% of maximum inspiratory pressure (MIP) for 6 weeks (MAX, n=22). A second group performed
James Nolan; Phillip D. Batin; Richard Andrews; Steven J. Lindsay; Paul Brooksby; Michael Mullen; Wazir Baig; Andrew D. Flapan; Alan Cowley; Robin J. Prescott; James M. M. Neilson; Keith A. A. Fox
Background—Patients with chronic heart failure (CHF) have a continuing high mortality. Autonomic dysfunction may play an important role in the pathophysiology of cardiac death in CHF. UK-HEART examined the value of heart rate variability (HRV) measures as independent predictors of death in CHF. Methods and Results—In a prospective study powered for mortality, we recruited 433 outpatients 62 69.6 years old
Copie, X; Le Heuzey, J Y; Iliou, M C; Pousset, F; Lavergne, T; Guize, L
The variability of the heart rate is reduced after myocardial infarction. It then progressively increases, to return to near normal values after several months. However, these changes in heart rate variability occur at the same time as slowing of the heart rate which makes interpretation difficult. Poincaré's diagram is constructed from a Holter recording plotting each RR interval against the preceding RR interval. The authors have developed a geometric approach to this diagram to evaluate parasympathetic tone for a given heart rate. By measuring the dispersion in height of the Poincaré's diagram, the authors evaluate the shor-term variability for a given RR interval. Two 24 hr Holter recordings were performed in 52 patients at one and two weeks after a myocardial infarction. The dispersion in the height of the Poincaré's diagrams was measured at the 10th, 25th, 50th, 75th and 90th percentiles of the total dispersion. The authors have shown an increase in the short-term variability of the shortest RR intervals (1th, 25th and 50th percentiles) which is not observed in the longer RR intervals (75th and 90th percentiles). In conclusion, theres is an increase in the heart rate variability at the shortest RR intervals. This suggests that the recovery of parasympathic tone after myocardial infarction occurs mainly at the fastest heart rates. PMID:8745997
Schrack, Jennifer A.; Zipunnikov, Vadim; Goldsmith, Jeff; Bandeen-Roche, Karen; Crainiceanu, Ciprian M.; Ferrucci, Luigi
Background Accurate measurement of free-living energy expenditure is vital to understanding changes in energy metabolism with aging. The efficacy of heart rate as a surrogate for energy expenditure is rooted in the assumption of a linear function between heart rate and energy expenditure, but its validity and reliability in older adults remains unclear. Objective To assess the validity and reliability of the linear function between heart rate and energy expenditure in older adults using different levels of calibration. Design Heart rate and energy expenditure were assessed across five levels of exertion in 290 adults participating in the Baltimore Longitudinal Study of Aging. Correlation and random effects regression analyses assessed the linearity of the relationship between heart rate and energy expenditure and cross-validation models assessed predictive performance. Results Heart rate and energy expenditure were highly correlated (r?=?0.98) and linear regardless of age or sex. Intra-person variability was low but inter-person variability was high, with substantial heterogeneity of the random intercept (s.d.?=?0.372) despite similar slopes. Cross-validation models indicated individual calibration data substantially improves accuracy predictions of energy expenditure from heart rate, reducing the potential for considerable measurement bias. Although using five calibration measures provided the greatest reduction in the standard deviation of prediction errors (1.08 kcals/min), substantial improvement was also noted with two (0.75 kcals/min). Conclusion These findings indicate standard regression equations may be used to make population-level inferences when estimating energy expenditure from heart rate in older adults but caution should be exercised when making inferences at the individual level without proper calibration. PMID:24787146
Wessel, Niels; Riedl, Maik; Kurths, Jürgen
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?"
Jorge Pinto Ribeiro; José Manuel Ibáńez; Ricardo Stein
Summary To evaluate the validity of the Rosenblueth-Simeone model for the heart rate response to incremental dynamic exercise, 11 healthy men performed maximal exercise tests on a cycle ergometer after administration of placebo, propranolol, atropine or both propranolol and atropine. The model showed that the influence of sympathetic activity on heart rate increased at intensities up to those which resulted in
Sharpley, Christopher F.; And Others
Assessed Type A behavior pattern for 122 teenagers who had heart rate measured during rest and presentation of mental arithmetic stressor under timed and competitive conditions. Examined whether sex, age, task performance, and behavior pattern predicted heart rate reactivitiy. Found no significant main effects for behavior pattern, sex, or age;…
M. V. Kamath; T. Bentley; R. Spaziani; G. Tougas; E. L. Fallen; N. McCartney; J. Runions; A. R. M. Upton
An imbalance in the autonomic nervous system has been suspected in patients with coronary artery disease during episodes of silent ischemia. Frequency analysis of the beat-to-beat heart rate variability (HRV) signals reveals a signature of autonomic regulation of the heart. We performed time-frequency analysis of HRV records containing silent ischemic episodes. In 14 out of 17 (82%) HRV data sets
Priest, Simon; Montelpare, William
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…
Wells, Ruth; Outhred, Tim; Heathers, James A. J.; Quintana, Daniel S.; Kemp, Andrew H.
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
Tadeusz Stach; T. C. Nicholas Graham; Jeffrey Yim; Ryan E. Rhodes
Exercise video games combine entertainment and physical movement in an effort to encourage people to be more physically active. Multiplayer exercise games take advantage of the motivating aspects of group activity by allowing people to exercise together. However, people of significantly different fitness levels can have a hard time playing together, as large differences in performance can be demotivating. To
Paul B Laursen; Wade L Knez; Cecilia M Shing; Robert H Langill; Edward C Rhodes; David G Jenkins
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?·?min) performed
Raghavendra, BR; Telles, S; Manjunath, NK; Deepak, KK; Naveen, KV; Subramanya, P
Background/Aims: One month of yoga training has been shown to reduce the pulse rate voluntarily without using external cues. Hence, the present study was designed to understand the strategies used by yoga practitioners and autonomic changes associated with voluntary heart rate reduction. Materials and Methods: Fifty volunteers (group mean age ± S.D., 25.4 ± 4.8 years; 25 males) were assessed in two trials on separate days. Each trial was for 12 minutes, with a ‘pre’ state and ‘during’ state of 6 minutes each. For both trials the ‘pre’ state was relaxation with eyes closed. In the ‘during’ state of Trial I, subjects were asked to voluntarily reduce their heart rate using a strategy of their choice. From their responses to specific questions it was determined that 22 out of 50 persons used breath regulation as a strategy. Hence, in the ‘during’ state of Trial II, subjects were asked to voluntarily reduce their heart rate by breath regulation. Results: In the first trial, the heart rate was reduced by an average of 19.6 beats per minute and in the second trial (with breath regulation exclusively) an average decrease of 22.2 beats per minute was achieved. Conclusions: Hence, the strategy used did not markedly alter the outcome. PMID:23440267
Stephenson, R; Butler, P J; Woakes, A J
Diving behaviour and heart rate were monitored in tufted ducks diving under circumstances which simulated various environmental conditions such as feeding under ice in winter. When distance to food was increased on a covered outdoor pond, dive duration increased proportionately, but it was calculated that time available for feeding was reduced during the longer-distance 'extended' dives. There was a gradual reduction in heart rate to 77.3 +/- 13.8 beats min-1, which is significantly lower than the resting value of 121.1 +/- 14.1 beats min-1, during the course of extended dives, suggesting that the ducks could gradually switch over to a 'classical' oxygen-conserving response during these prolonged voluntary dives. The duration of the pre-dive preparatory period was positively correlated with dive distance. When the ducks were briefly unable to resurface during an otherwise normal feeding dive in an indoor tank, a situation which may occur if they become disoriented under ice, there was an immediate switch to a full bradycardia. Reduction in heart rate during these 'enclosed' dives occurred only when the ducks were apparently aware of the situation and the rate of onset of bradycardia was very similar to that previously observed during involuntary submersion of tufted ducks. Minimum heart rate was the same at 46 beats min-1 after 15 s of enclosed dives and after 30 s of involuntary submersions, despite the differences in levels of activity in the two situations. PMID:3805996
A new measure of acceleration of heart rate: dependence on age and comparison with time domain conventional heart rate variability measures Giuseppe GermanĂ˛, M.D., Gianfranco Piccirillo, M.D., *Camillo The heart rate variability (HRV) results from a variety of factors that are not purely stochastic
Qian, Yi; Tsien, Joe Z.
Non-contact and low-cost measurements of heart and respiration rates are highly desirable for telemedicine. Here, we describe a novel technique to extract blood volume pulse and respiratory wave from a single channel images captured by a video camera for both day and night conditions. The principle of our technique is to uncover the temporal dynamics of heart beat and breathing rate through delay-coordinate transformation and independent component analysis-based deconstruction of the single channel images. Our method further achieves robust elimination of false positives via applying ratio-variation probability distributions filtering approaches. Moreover, it enables a much needed low-cost means for preventing sudden infant death syndrome in new born infants and detecting stroke and heart attack in elderly population in home environments. This noncontact-based method can also be applied to a variety of animal model organisms for biomedical research. PMID:24115996
Background Diabetes may confer an increased risk for the cardiovascular health effects of particulate air pollution, but few human clinical studies of air pollution have included people with diabetes. Ultrafine particles (UFP, ?100 nm in diameter) have been hypothesized to be an important component of particulate air pollution with regard to cardiovascular health effects. Methods 17 never-smoker subjects 30–60 years of age, with stable type 2 diabetes but otherwise healthy, inhaled either filtered air (0–10 particles/cm3) or elemental carbon UFP (~107 particles/cm3, ~50 ug/m3, count median diameter 32 nm) by mouthpiece, for 2 hours at rest, in a double-blind, randomized, crossover study design. A digital 12-lead electrocardiogram (ECG) was recorded continuously for 48 hours, beginning 1 hour prior to exposure. Results Analysis of 5-minute segments of the ECG during quiet rest showed reduced high-frequency heart rate variability with UFP relative to air exposure (p?=?0.014), paralleled by non-significant reductions in time-domain heart rate variability parameters. In the analysis of longer durations of the ECG, we found that UFP exposure increased the heart rate relative to air exposure. During the 21- to 45-hour interval after exposure, the average heart rate increased approximately 8 beats per minute with UFP, compared to 5 beats per minute with air (p?=?0.045). There were no UFP effects on cardiac rhythm or repolarization. Conclusions Inhalation of elemental carbon ultrafine particles alters heart rate and heart rate variability in people with type 2 diabetes. Our findings suggest that effects may occur and persist hours after a single 2-hour exposure. PMID:25028096
Femida H. Gwadry-Sridhar; Virginia Flintoft; Douglas S. Lee; Hui Lee; Gordon H. Guyatt
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
Boudreau, Philippe; Yeh, Wei-Hsien; Dumont, Guy A.; Boivin, Diane B.
Study Objectives: Nocturnal cardiovascular events are more frequent at the beginning and end of the night. It was proposed that this pattern reflects the nocturnal distribution of sleep and sleep stages. Using heart rate variability (HRV), we recently showed an interaction between the circadian system and vigilance states on the regulation of cardiac rhythmicity. Here, we further investigate this interaction in order to clarify the specific effects of sleep stages on the regulation of the heart. Design: Participants underwent a 72-h ultradian sleep-wake cycle procedure in time isolation consisting of alternating 60-min wake episodes in dim light and 60-min nap opportunities in total darkness. Setting: Time isolation suite. Patients or participants: Fifteen healthy young participants; two were subsequently excluded. Interventions: N/A. Measurements and Results: The current study revealed that sleep onset and progression to deeper sleep stages was associated with a shift toward greater parasympathetic modulation, whereas rapid eye movement (REM) sleep was associated with a shift toward greater sympathetic modulation. We found a circadian rhythm of heart rate (HR) and high-frequency power during wakefulness and all non-REM sleep stages. A significant circadian rhythm of HR and sympathovagal balance of the heart was also observed during REM sleep. During slow wave sleep, maximal parasympathetic modulation was observed at ?02:00, whereas during REM sleep, maximal sympathetic modulation occurred in the early morning. Conclusion: The circadian and sleep stage-specific effects on heart rate variability are clinically relevant and contribute to the understanding of the degree of cardiovascular vulnerability during sleep. Citation: Boudreau P; Yeh WH; Dumont GA; Boivin DB. Circadian variation of heart rate variability across sleep stages. SLEEP 2013;36(12):1919-1928. PMID:24293767
Ergun Baris Kaya; Sercan Okutucu; Hakan Aksoy; Ugur Nadir Karakulak; Erol Tulumen; Oya Ozdemir; Fatma Inanici; Kudret Aytemir; Giray Kabakci; Lale Tokgozoglu; Hilmi Ozkutlu; Ali Oto
Objective The aim of this study was to evaluate heart rate variability (HRV) and heart rate recovery (HRR) in otherwise healthy ankylosing\\u000a spondlitis (AS) patients and control subjects.\\u000a \\u000a \\u000a \\u000a \\u000a Methods A total of 28 patients with AS and 30 volunteers matched for age and sex were enrolled. All subjects underwent HRV analysis,\\u000a exercise testing (ET), and transthoracic echocardiography. HRR indices were calculated by
David J. Girling
Electrocardiogram, heart rate, blood pressure, and pattern of respiration were recorded continuously in 8 newborn babies having apnoeic attacks. Apnoeic attacks usually occurred without any premonitory changes in respiration, heart rate, or blood pressure. The heart rate usually fell during an apneoic attack and did so after the onset of apnoea. The pulse pressure most commonly rose as the heart
Harvey B Lillywhite; Kevin C Zippel; Anthony P Farrell
Resting and maximal heart rates (HR) in ectothermic vertebrates are generally lower than those in endotherms and vary by more than an order of magnitude interspecifically. Variation of HR transcends phylogeny and is influenced by numerous factors including temperature, activity, gas exchange, intracardiac shunts, pH, posture, and reflexogenic regulation of blood pressure. The characteristic resting HR is rarely the intrinsic
Kisilevsky, Barbara S.; Hains, Sylvia M. J.
A relationship between fetal heart rate (HR) and cognition is explored within the context of infant, child and adult studies where the association is well established. Lack of direct access to the fetus and maturational changes limit research paradigms and response measures for fetal studies. Nevertheless, neural regulation of HR shows a number of…
LeFevers, Victoria A.
Thirty five volunteer college women were divided into three groups to determine if heart rate could be conditioned instrumentally and lowered during exercise stress on the treadmill. The three groups were a) experimental group I, 15 subjects who received instrumental conditioning with visual feedback; b) instrumental group II, 9 subjects who…
Tipton, Jan; Sander, Allan N.
National health and fitness data suggests that a significant percentage of children are not on a pathway to leading healthy, physically active lifestyles. Many children are leading sedentary lifestyles due to a lack of opportunity, success, or self-motivation in physical activity. Programs that highlight the use of heart rate monitors offer a…
Sanghoon Lee; Myeong Soo Lee; Jun-Yong Choi; Seung-Won Lee; Sang-Yong Jeong; Edzard Ernst
Acupuncture has been reported to affect the autonomic system. Currently, there are no systematic reviews examining the effect of acupuncture on HRV available in the literature. Therefore, the aim of this systematic review was to summarize and critically assess the effects of acupuncture on heart rate variability. We searched the literature using 14 databases for articles published from the earliest
1 Heart Physiology Worksheet Table 1. Pulse Rate Data Individual Lying down Sitting Standing During for blood pressure measurements. 0 20 40 60 80 100 120 140 160 180 200 220 240 Lying Standing 3 Min Exercise these effects occurred. 2. Blood Pressure: Based on examination of your line graph a. What is the effect
Amir Weissman; Elad Berkowitz; Tatiana Smolkin; Shraga Blazer
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
Asker Jeukendrup; Adrie Van Diemen
To obtain optimal training effects and avoid overtraining, it is necessary to monitor the intensity of training. In cycling, speed is not an accurate indicator of exercise intensity, and therefore alternatives have to be found to monitor exercise intensity during training and competition. Power output may be the most direct indicator, but heart rate is easier to monitor and measure.
Ernst H. Jager
Formulas are proposed for the ranges of normal heart rate and blood pressure during dynamic exercise. They apply to normotensive men and women approximately 20–50 years old. The numerical values of the parameters may have to be modified for other populations, partial populations or other age groups.
Incalzi, Raffaele Antonelli; Corsonello, Andrea; Trojano, Luigi; Pedone, Claudio; Acanfora, Domenico; Spada, Aldo; D'Addio, Gianni; Maestri, Roberto; Rengo, Franco; Rengo, Giuseppe
We studied 54 patients with hypoxemic chronic obstructive pulmonary disease (COPD). The Mini Mental State Examination and the Mental Deterioration Battery were used for neuropsychological assessment. Heart rate variability (HRV) was assessed based on 24-h Holter ECG recording. Mann-Whitney test was used to compare HRV parameters of patients…
Toscano, W. B.; Cowings, P. S.
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.
James, David V. B.; Munson, Steven C.; Maldonado-Martin, Sara; De Ste Croix, Mark B. A.
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…
R. STEPHENSON; P. J. BUTLER; A. J. WOAKES
SUMMARY Diving behaviour and heart rate were monitored in tufted ducks diving under circumstances which simulated various environmental conditions such as feeding under ice in winter. When distance to food was increased on a covered outdoor pond, dive duration increased proportionately, but it was calculated that time available for feeding was reduced during the longer-distance 'extended' dives. There was a
Elwess, Nancy L.; Vogt, F. Daniel
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…
Karageorghis, Costas I.; Jones, Leighton; Low, Daniel C.
The present study examined the predicted positive and linear relationship (Iwanaga, 1995a, 1995b) between exercise heart rate and music tempo preference. Initially, 128 undergraduate students (M age = 20.0 years, SD = 0.9) were surveyed to establish their three favorite music artists. A separate experimental group of 29 undergraduates (M age =…
Mourot, Laurent; Fabre, Nicolas; Andersson, Erik; Willis, Sarah; Buchheit, Martin; Holmberg, Hans-Christer
Postexercise heart-rate (HR) recovery (HRR) indices have been associated with running and cycling endurance-exercise performance. The current study was designed (1) to test whether such a relationship also exists in the case of cross-country skiing (XCS) and (2) to determine whether the magnitude of any such relationship is related to the intensity of exercise before obtaining HRR indices. Ten elite male cross-country skiers (mean ± SD; 28.2 ± 5.4 y, 181 ± 8 cm, 77.9 ± 9.4 kg, 69.5 ± 4.3 mL · min-1 · kg-1 maximal oxygen uptake [VO2max]) performed 2 sessions of roller-skiing on a treadmill: a 2 × 3-km time trial and the same 6-km at an imposed submaximal speed followed by a final 800-m time trial. VO2 and HR were monitored continuously, while HRR and blood lactate (BLa) were assessed during 2 min immediately after each 6-km and the 800-m time trial. The 6-km time-trial time was largely negatively correlated with VO2max and BLa. On the contrary, there was no clear correlation between the 800-m time-trial time and VO2, HR, or BLa. In addition, in no case was any clear correlation between any of the HRR indices and performance time or VO2max observed. These findings confirm that XCS performance is largely correlated with VO2max and the ability to tolerate high levels of BLa; however, postexercise HRR showed no clear association with performance. The homogeneity of the group of athletes involved and the contribution of the arms and upper body to the exercise preceding determination of HRR may explain this absence of a relationship. PMID:24806737
Xu, Liang; Redman, Christopher W G; Payne, Stephen J; Georgieva, Antoniya
The fetal heart rate (FHR) is monitored on a paper strip (cardiotocogram) during labour to assess fetal health. If necessary, clinicians can intervene and assist with a prompt delivery of the baby. Data-driven computerized FHR analysis could help clinicians in the decision-making process. However, selecting the best computerized FHR features that relate to labour outcome is a pressing research problem. The objective of this study is to apply genetic algorithms (GA) as a feature selection method to select the best feature subset from 64 FHR features and to integrate these best features to recognize unfavourable FHR patterns. The GA was trained on 404 cases and tested on 106 cases (both balanced datasets) using three classifiers, respectively. Regularization methods and backward selection were used to optimize the GA. Reasonable classification performance is shown on the testing set for the best feature subset (Cohen's kappa values of 0.45 to 0.49 using different classifiers). This is, to our knowledge, the first time that a feature selection method for FHR analysis has been developed on a database of this size. This study indicates that different FHR features, when integrated, can show good performance in predicting labour outcome. It also gives the importance of each feature, which will be a valuable reference point for further studies. PMID:24854596
CARNEY, ROBERT M.; FREEDLAND, KENNETH E.
Depression is common in patients with coronary heart disease (CHD) and is a risk factor for cardiac morbidity and mortality in these patients. Depression is associated with autonomic nervous system dysfunction, which may at least partially explain this increased risk. Low heart rate variability (HRV), which reflects excessive sympathetic and/or inadequate parasympathetic modulation of heart rate, is a strong predictor of mortality in patients with CHD. Most studies—both in patients with stable CHD and in patients with a recent acute coronary event—have found HRV to be lower in depressed patients than in their nondepressed counterparts. This manuscript provides an overview of this literature and concludes that HRV may account for a substantial part of the risk associated with depression in CHD. PMID:19376975
Tenan, Matthew S; Brothers, R Matthew; Tweedell, Andrew J; Hackney, Anthony C; Griffin, Lisa
Heart rate variability (HRV) is a noninvasive indicator of autonomic control. This study examines HRV changes across a normal menstrual cycle and proposes a novel piecewise function controlling for the effects of breathing on HRV spectral parameters. A resting ECG was collected from 13 women at five points in their menstrual cycle. Both heart rate and breathing rate increased across the cycle (p?.01) while time-domain variability decreased (p?=?.04). Use of the piecewise function for breathing rate in HRV spectral analysis was confirmed by a substantial increase in model goodness-of-fit. HRV spectral parameters, controlled for breathing with the piecewise function, confirm that the decrease in variability is likely due to a parasympathetic withdrawal, since high frequency HRV decreases (p?=?.02). PMID:24942292
Double blind crossover comparison of the effects of dual chamber pacing (DDD) and ventricular rate adaptive (VVIR) pacing on neuroendocrine variables, exercise performance, and symptoms in complete heart block
K G Oldroyd; A P Rae; R Carter; C Wingate; S M Cobbe
OBJECTIVE--To compare the effects of dual chamber pacing (DDD) and ventricular rate adaptive pacing (activity sensing) (VVIR) in patients with complete heart block. DESIGN--Double blind crossover comparison with one month in each pacing mode. PATIENTS--10 consecutive patients aged 23-74 presenting with complete anterograde atrioventricular block at rest and on exercise and with an intact atrial rate response received Synergyst I
Background We investigated the association between heart rate and its variability with the parameters that assess vascular, renal and cardiac target organ damage. Methods A cross-sectional study was performed including a consecutive sample of 360 hypertensive patients without heart rate lowering drugs (aged 56 ± 11 years, 64.2% male). Heart rate (HR) and its standard deviation (HRV) in clinical and 24-hour ambulatory monitoring were evaluated. Renal damage was assessed by glomerular filtration rate and albumin/creatinine ratio; vascular damage by carotid intima-media thickness and ankle/brachial index; and cardiac damage by the Cornell voltage-duration product and left ventricular mass index. Results There was a positive correlation between ambulatory, but not clinical, heart rate and its standard deviation with glomerular filtration rate, and a negative correlation with carotid intima-media thickness, and night/day ratio of systolic and diastolic blood pressure. There was no correlation with albumin/creatinine ratio, ankle/brachial index, Cornell voltage-duration product or left ventricular mass index. In the multiple linear regression analysis, after adjusting for age, the association of glomerular filtration rate and intima-media thickness with ambulatory heart rate and its standard deviation was lost. According to the logistic regression analysis, the predictors of any target organ damage were age (OR = 1.034 and 1.033) and night/day systolic blood pressure ratio (OR = 1.425 and 1.512). Neither 24 HR nor 24 HRV reached statistical significance. Conclusions High ambulatory heart rate and its variability, but not clinical HR, are associated with decreased carotid intima-media thickness and a higher glomerular filtration rate, although this is lost after adjusting for age. Trial Registration ClinicalTrials.gov: NCT01325064 PMID:22439900
González-Landaeta, R; Casas, O; Pallŕs-Areny, R
We propose a novel technique for beat-to-beat heart rate detection based on the ballistocardiographic (BCG) force signal from a subject standing on a common electronic weighing scale. The detection relies on sensing force variations related to the blood acceleration in the aorta, works even if wearing footwear and does not require any sensors attached to the body because it uses the load cells in the scale. We have devised an approach to estimate the sensitivity and frequency response of three commercial weighing scales to assess their capability to detect the BCG force signal. Static sensitivities ranged from 490 nV V(-1) N(-1) to 1670 nV V(-1) N(-1). The frequency response depended on the subject's mass but it was broad enough for heart rate estimation. We have designed an electronic pulse detection system based on off-the-shelf integrated circuits to sense heart-beat-related force variations of about 0.24 N. The signal-to-noise ratio of the main peaks of the force signal detected was higher than 30 dB. A Bland-Altman plot was used to compare the RR time intervals estimated from the ECG and BCG force signals for 17 volunteers. The error was +/-21 ms, which makes the proposed technique suitable for short-term monitoring of the heart rate. PMID:18641428
Hung-Wen Chiu; Ti-Ho Wang; Lu-Chou Huang; Han-Wen Tso; Tsair Kao
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
T. R. Rietmann; A. E. A. Stuart; P. Bernasconi; M. Stauffacher; J. A. Auer; M. A. Weishaupt
The aim of the study was to investigate whether heart rate variability (HRV) could assess alterations of the autonomic nervous system (ANS) at different levels of excitement. The behavioural and physiological responses of 20 warmblood horses to a challenging ground exercise task were studied. Prior to the experiment, the horses were evaluated at rest and during forward walking (FW). The
M. McCarthy; J. V. Ringwood
Using a mathematical procedure, we determine appropriate sampling rates for logging heart rate, at a variety of exercise intensities. The mathematical procedure involves correlating exercise and heart rate data to determine a dynamical mathematical model, from which the frequency response of the relationship between exercise intensity and heart rate can be determined. The sampling rate is then straightforwardly deduced by
Rowena Uy; Nikola Tede; Nancy Ross-Ascuitto; Robert Ascuitto
Isolated, paced, isovolumically beating, neonatal pig (n = 32) hearts underwent retrograde aortic perfusion with a solution containing insulin (100 ?U\\/ml), glucose (5.5 mM), and palmitate (0.55 mM). Glycolysis, lactate release, glucose oxidation, palmitate oxidation, and oxygen consumption were assessed. The hearts were perfused during three periods: (1) baseline, pO2 ≈ 500 mm Hg, heart rate 150 bpm; (2) hypoxia,
Amirian, Ilda; Andersen, Lćrke Toftegĺrd; Rosenberg, Jacob; Gögenur, Ismail
Background Heart rate variability (HRV) has been used as a measure of stress and mental strain in surgeons. Low HRV has been associated with death and increased risk of cardiac events in the general population. The aim of this study was to clarify the effect of a 17-hour night shift on surgeons’ HRV. Methods Surgeons were monitored prospectively with an ambulatory electrocardiography device for 48 consecutive hours, beginning on a precall day and continuing through an on-call (17-h shift) day. We measured HRV by frequency domain parameters. Results We included 29 surgeons in our analysis. The median pulse rate was decreased precall (median 64, interquartile range [IQR] 56–70 beats per minute [bpm]) compared with on call (median 81, IQR 70–91 bpm, p < 0.001). Increased high-frequency (HF) activity was found precall (median 199, IQR 75–365 ms2) compared with on call (median 99, IQR 48–177 ms2, p < 0.001). The low-frequency:high-frequency (LF:HF) ratio was lower precall (median 2.7, IQR 1.9–3.9) than on call (median 4.9, IQR 3.7–6.5, p < 0.001). We found no correlation between the LF:HF ratio and performance in laparoscopic simulation. Conclusion Surgeons working night shifts had a significant decrease in HRV and a significant increase in pulse rate, representing sympathetic dominance in the autonomic nervous system. Trial registration NCT01623674 (www.clinicaltrials.gov). PMID:25265102
Wang Xing; Xu Liang; Sun Zhongwei; Yang Zibin; Peng Yi
ST-segment deviation is the routine method for the diagnosis of coronary heart diseases. However, other phenomena, such as heart rate changes and a posture change can cause similar manifestations in the ST segment, lowing the sensitivity and specificity of the detection. In this study, a different method, based on time-frequency analysis of heart rate variability, was proposed to evaluate the
Sugihara, George; Allan, Walter; Sobel, Daniel; Allan, Kenneth D.
Nonlinear analyses of infant heart rhythms reveal a marked rise in the complexity of the electrocardiogram with maturation. We find that normal mature infants (gestation >= 35 weeks) have complex and distinctly nonlinear heart rhythms (consistent with recent reports for healthy adults) but that such nonlinearity is lacking in preterm infants (gestation <= 27 weeks) where parasympathetic-sympathetic interaction and function are presumed to be less well developed. Our study further shows that infants with clinical brain death and those treated with atropine exhibit a similar lack of nonlinear feedback control. These three lines of evidence support the hypothesis championed by Goldberger et al. [Goldberger, A. L., Rigney, D. R. & West, B. J. (1990) Sci. Am. 262, 43-49] that autonomic nervous system control underlies the nonlinearity and possible chaos of normal heart rhythms. This report demonstrates the acquisition of nonlinear heart rate dynamics and possible chaos in developing human infants and its loss in brain death and with the administration of atropine. It parallels earlier work documenting changes in the variability of heart rhythms in each of these cases and suggests that nonlinearity may provide additional power in characterizing physiological states.
Cash, W. H., Jr.; Polhemus, J. T. (inventors)
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.
Alfred Nimmerichter; Roger G. Eston; Norbert Bachl; Craig Williams
Power output and heart rate were monitored for 11 months in one female ([Vdot]O2max: 71.5 mL · kg · min) and ten male ([Vdot]O2max: 66.5 ± 7.1 mL · kg · min) cyclists using SRM power-meters to quantify power output and heart rate distributions in an attempt to assess exercise intensity and to relate training variables to performance. In total, 1802 data sets were divided into workout categories according to
García-Massó, X; Serra-Ańó, P; García-Raffi, L; Sánchez-Pérez, E; Giner-Pascual, M; González, L-M
The aim of the present study is to obtain models for estimating energy expenditure based on the heart rates of people with spinal cord injury without requiring individual calibration. A cohort of 20 persons with spinal cord injury performed a routine of 10 activities while their breath-by-breath oxygen consumption and heart rates were monitored. The minute-by-minute oxygen consumption collected from minute 4 to minute 7 was used as the dependent variable. A total of 7 features extracted from the heart rate signals were used as independent variables. 2 mathematical models were used to estimate the oxygen consumption using the heart rate: a multiple linear model and artificial neural networks. We determined that the artificial neural network model provided a better estimation (r=0.88, MSE=4.4?ml?·?kg(-1)?·?min(-1)) than the multiple linear model (r=0.78; MSE=7.63?ml?·?kg(-1)?·?min(-1)).The goodness of fit with the artificial neural network was similar to previous reported linear models involving individual calibration. In conclusion, we have validated the use of the heart rate to estimate oxygen consumption in paraplegic persons without individual calibration and, under this constraint, we have shown that the artificial neural network is the mathematical tool that provides the better estimation. PMID:24886923
Saul, J. P.; Albrecht, P.; Berger, R. D.; Cohen, R. J.
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.
Pollatos, Olga; Herbert, Beate M; Matthias, Ellen; Schandry, Rainer
The perception of visceral signals plays a crucial role in many theories of emotions. The present study was designed to investigate the relationship between interoceptive awareness, emotional experience and heart rate responses in an emotional stimulation paradigm. Based on their performance in a heartbeat perception task 38 participants (16 males, 22 females) were classified as subjects with either high (n=19; 8 males) or low interoceptive awareness (n=19; 8 males). 120 pictures (40 pleasant, 40 unpleasant, 40 neutral slides) from the International Affective Picture System served as emotional stimuli. Heart rate changes were recorded during baseline and during slide presentation. After each slide, the subjects had to rate emotional valence and arousal on a 9-point self-report scale. Statistical analyses revealed significantly stronger heart rate responses to pleasant and unpleasant stimuli in subjects with high interoceptive awareness. Furthermore, subjects with high interoceptive awareness rated pleasant and unpleasant slides as significantly more arousing; no differences were found in the emotional valence ratings. Heartbeat perception scores correlated significantly positive with both the mean arousal rating and with the mean heart rate changes. Our results demonstrate a strong relationship between the perception of cardiac signals and the peripheral processing of emotional stimuli. PMID:17137662
Vincent PICHOT; Jean-Michel GASPOZ; Franck ENJOLRAS; Anestis ANTONIADIS; Pascal MININI; Thierry BUSSO
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,
Mary McGrae McDermott; Joe Feinglass; Peter I. Lee; Shruti Mehta; Brian Schmitt; Frank Lefevre; Mihai Gheorghiade
We sought to describe the relation between left ventricular systolic function and rates of hospital readmission and survival among consecutively hospitalized patients with congestive heart failure. Medical records were reviewed for these patients at an academic medical center between Jan. 1, 1992, and Dec. 31, 1993. Left ventricular systolic function assessments performed within 6 months before discharge were used to
H.-W. M. Breuer; St. Charchut; H. Worth
Summary To investigate the effects of several endoscopic procedures like introduction of the bronchoscope, removal of the instrument, catheter suction, bronchoalveolar lavage and transbronchial biopsy on heart rate, systemic blood pressure, and transcutaneously measured blood gases 77 consecutive patients (age, 20–83 years) were studied. All patients received 10 l O2\\/min via face mask during bronchoscopy. Sedation was performed with midazolam
K. Baum; D. Essfeld; J. Stegemann
Summary To investigate the effect of local dehydration on heart rate and blood pressure during static exercise, six healthy male subjects performed exercise of the calf muscles with different extracellular volumes of the working muscles. Exercise consisted of 5 min of static calf muscle contractions at about 10% of maximal voluntary contraction. The body position during exercise was identical in all
Successful performance in aerobic distance running is dependant on the athlete's ability to cover a fixed distance in the shortest time possible. An effective distance runner's programme must include an exercise prescription specifically developed for the individual athlete. In this regard, a percentage of either measured or predicted maximum heart rate is commonly used to prescribe and measure exercise intensity.
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...
Heart rate dynamics during three forms of meditation C.-K. Penga,*, Isaac C. Henrya , Joseph E and cardiopulmonary interactions during sequential performance of three meditation protocols with different breathing experienced meditators (4 females; 6 males; mean age 42 years; range 29Â55 years) during three traditional
Cuevas, Kimberly; Bell, Martha Ann; Marcovitch, Stuart; Calkins, Susan D.
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…
Chung, Joanne W. Y.; Yan, Vincent C. M.
Aim. To summarize all relevant trials and critically evaluate the effect of acupuncture on heart rate variability (HRV). Method. This was a systematic review with meta-analysis. Keyword search was conducted in 7 databases for randomized controlled trials (RCTs). Data extraction and risk of bias were done. Results. Fourteen included studies showed a decreasing effect of acupuncture on low frequency (LF) and low frequency to high frequency ratio (LF/HF ratio) of HRV for nonhealthy subjects and on normalized low frequency (LF norm) for healthy subjects. The overall effect was in favour of the sham/control group for high frequency (HF) in nonhealthy subjects and for normalized high frequency (HF norm) in healthy subjects. Significant decreasing effect on HF and LF/HF ratio of HRV when acupuncture was performed on ST36 among healthy subjects and PC6 among both healthy and nonhealthy subjects, respectively. Discussion. This study partially supports the possible effect of acupuncture in modulating the LF of HRV in both healthy and nonhealthy subjects, while previous review reported that acupuncture did not have any convincing effect on HRV in healthy subjects. More published work is needed in this area to determine if HRV can be an indicator of the therapeutic effect of acupuncture. PMID:24693326
Peng, Rong-Chao; Zhou, Xiao-Lin; Lin, Wan-Hua; Zhang, Yuan-Ting
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
Abtahi, F; Berndtsson, A; Abtahi, S; Seoane, F; Lindecrantz, K
The reduced Heart Rate Variability (HRV) is believed to be associated with several diseases such as congestive heart failure, diabetes and chronic kidney diseases (CKD). In these cases, HRV biofeedback may be a potential intervention method to increase HRV which in turn is beneficial to these patients. In this work, a real-time Android biofeedback application based on a Bluetooth enabled ECG and thoracic electrical bioimpedance (respiration) measurement device has been developed. The system performance and usability have been evaluated in a brief study with eight healthy volunteers. The result demonstrates real-time performance of system and positive effects of biofeedback training session by increased HRV and reduced heart rate. Further development of the application and training protocol is ongoing to investigate duration of training session to find an optimum length and interval of biofeedback sessions to use in potential interventions. PMID:25570716
M. Ronzhina; O. Janousek; P. Scheer; M. Novakova; I. Provaznik; J. Kolarova
There are many different methods for diagnosis of cardiac disorders. One of them is spectral analysis of heart rate variability (HRV). Its frequency bands are standardized only for human hearts. The present study is focused on definition of frequency bands in isolated hearts of New Zealand rabbits and on analysis of changes of these bands caused by myocardial ischemia. The
Matchett, Gerald; Wood, Philip
The human heart normally exhibits robust beat-to-beat heart rate variability (HRV). The loss of this variability is associated with pathology, including disease states such as congestive heart failure (CHF). The effect of general anesthesia on intrinsic HRV is unknown. In this prospective, observational study we enrolled 100 human subjects having elective major surgical procedures under general anesthesia. We recorded continuous heart rate data via continuous electrocardiogram before, during, and after anesthesia, and we assessed HRV of the R-R intervals. We assessed HRV using several common metrics including Detrended Fluctuation Analysis (DFA), Multifractal Analysis, and Multiscale Entropy Analysis. Each of these analyses was done in each of the four clinical phases for each study subject over the course of 24 h: Before anesthesia, during anesthesia, early recovery, and late recovery. On average, we observed a loss of variability on the aforementioned metrics that appeared to correspond to the state of general anesthesia. Following the conclusion of anesthesia, most study subjects appeared to regain their normal HRV, although this did not occur immediately. The resumption of normal HRV was especially delayed on DFA. Qualitatively, the reduction in HRV under anesthesia appears similar to the reduction in HRV observed in CHF. These observations will need to be validated in future studies, and the broader clinical implications of these observations, if any, are unknown.
Routledge, Faye S; Campbell, Tavis S; McFetridge-Durdle, Judith A; Bacon, Simon L
Heart rate variability (HRV) is a noninvasive, practical and reproducible measure of autonomic nervous system function. A heart rate that is variable and responsive to demands is believed to bestow a survival advantage, whereas reduced HRV may be associated with poorer cardiovascular health and outcomes. In recent years, many researchers have investigated the prognostic implications of HRV in a variety of clinical populations. Evidence suggests that reduced HRV has prognostic significance for individuals with myocardial infarction, chronic heart failure, unstable angina and diabetes mellitus. Interventions to increase HRV, such as exercise therapy, have also been examined. The findings of the present review suggest that exercise therapy may improve HRV in myocardial infarction, chronic heart failure and revascularization patients by increasing vagal tone and decreasing sympathetic activity. One hypothesis is that a shift toward greater vagal modulation may positively affect the prognosis of these individuals. While the underlying mechanisms by which exercise training improves vagal modulation are speculative at present, angiotensin II and nitric oxide may be potential mediators. PMID:20548976
Mukharji, Auyon; Drucker, Daniel J; Charron, Maureen J; Swoap, Steven J
Two hormones from the gastrointestinal tract, glucagon and oxyntomodulin (OXM), vigorously elevate the intrinsic heart rate (IHR) of mice. We have previously shown that OXM influences murine heart rate (HR) independent of the glucagon-like peptide 1 (GLP-1) receptor. Here, we demonstrate using radiotelemetry in mice deficient in the glucagon receptor (Gcgr ?/?) that both OXM and glucagon require the glucagon receptor for their chronotropic effects on the heart. Furthermore, we found that other hormones associated with hunger and satiety (ghrelin, leptin, and PYY3-36) had no effect on IHR, while cholecystokinin moderately elevated the IHR. Finally, the resting HR of Gcgr ?/? mice was higher than in control mice (Gcgr +/+ and Gcgr +/?) at thermal neutral temperature (30°C). Using atropine, we demonstrated that Gcgr ?/? mice have diminished parasympathetic (PNS) influence of the heart at this temperature. Gcgr ?/? mice displayed a normal bradycardia as compared to controls in response to administration of either methacholine (to activate the muscarinic acetylcholine receptor) or methoxamine (to activate the baroreflex through agonism of the ?1 adrenergic receptor agonist) suggesting that vagal pathways are intact in the Gcgr ?/? mice. As OXM is an agonist of the GLP-1 receptor and Gcgr with antidiabetic activity, we suggest OXM may be an alternative to glucagon in the treatment of overdose of beta-blockers to elevate HR in clinical conditions. PMID:24303183
: Comparison of HRV data between 72 healthy subjects and 43 with congestive heart failure (CHF); betweenCARDIOVASCULAR MEDICINE The pNNx files: re-examining a widely used heart rate variability measure J . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Heart 2002;88:378Â380 Objective: To re-examine the standard pNN50 heart rate variability (HRV) statistic
Paris-Sud XI, Université de
Heart Rate Regulation processed through wavelet analysis and change detection. Some case studies-mail: email@example.com December 29, 2010 Abstract Heart rate variability (HRV) is an indicator of the regulation of the heart engine, Task Force (1996). This study compares the regulation of the heart in two
an X-band Doppler radar system to detect heart and respiration of human far away. Through the idea and heart rates with the periodic movement of skin and muscle near the heart. Keywords-heart rate; X. The Basic Concept of the System The configuration of X-band Doppler radar system is shown in Figure 1
Lewalter, T; Jung, W; MacCarter, D; Bauer, T; Schimpf, R; Manz, M; Lüderitz, B
The objective of minute ventilation (MV)-controlled pacemaker algorithms is to simulate the physiologic relationship of the sensed signal and the sinus node response during exercise. In our study we determined the relationship between heart rate and MV in healthy middle-aged subjects by measuring breath-by-breath gas exchange throughout peak exercise. Regarding several clinical limitations of peak exercise testing, we additionally evaluated whether a 35 W low-intensity treadmill exercise (LITE) protocol can be used as a substitute for peak exercise testing to determine the physiologic heart rate to MV slope. The results demonstrated that the heart rate to MV relationship is not linear throughout peak exercise but is curvilinear with a smooth logarithmic-type profile. To simulate this relationship, MV-based rate adaptive pacemakers should generate a decreasing heart rate to MV slope during higher levels of work. The heart rate to MV slope determined during the early, dynamic phase of low-intensity exercise represents the same slope derived from peak exercise below the anaerobic threshold. The low-intensity treadmill exercise protocol, with minimal patient effort, can thus be used as a substitute for peak exercise to optimize rate adaptive slope programming of MV-controlled pacemakers. PMID:8160576
TRIBUTE TO STANLEY DODSON Chytrid infection reduces thoracic beat and heart rate of Daphnia observed simultaneously the heart rates and compared chytrid infected animals with uninfected gravid and non-gravid ones. We found in uninfected animals a thoracic beat rate of 3.81 ± 018 Hz and a heart rate
Wavelet packet modelling of infant sleep state using heart rate data Guy P. Nason, y Theofanis classification using heart rate data. The suggested approach produces adequate classification rates when applied, this approach gives us valuable information about the relationship between sleep state and heart rate
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) Ć Interbeat
Wavelet packet modelling of infant sleep state using heart rate data Guy P. Nason,Ăť Theofanis classification using heart rate data. The suggested approach produces adequate classification rates when applied, this approach gives us valuable information about the relationship between sleep state and heart rate
Alan D. Sirota; Gary E. Schwartz; David Shapiro
In anticipation of receiving painful stimuli, 20 female 21-27 yr old Ss learned to control their heart rate when provided with external feedback and reward for criterion heart rate changes and were instructed to increase or decrease their rate. Voluntary slowing of heart rate led to a relative reduction in the perceived aversiveness of the stimuli, particularly for those Ss
The heart rate variability is a useful method to assess cardiac autonomic modulation in patients undergoing dental procedures, because knowledge of physiological conditions provides greater security to the professional as well as the possibility of a better plan treatment to patient benefit. The aim of our study was to describe the association between cardiac autonomic control and dental variables. We consulted the databases Medline, SciELO, Lilacs and Cochrane, using the terms “autonomic”, “dentistry”, “heart rate variability”, “cardiovascular physiology.” The selected studies indicated a strong relationship between dental variables and HRV. There was an association between malocclusion, TMD, dental procedures cirugia and low HRV. Thus, they become more studies that relate to HRV in dental science, especially in clinical practice. PMID:24373329
Riese, Harriëtte; Muńoz, Loretto M.; Hartman, Catharina A.; Ding, Xiuhua; Su, Shaoyong; Oldehinkel, Albertine J.; van Roon, Arie M.; van der Most, Peter J.; Lefrandt, Joop; Gansevoort, Ron T.; van der Harst, Pim; Verweij, Niek; Licht, Carmilla M. M.; Boomsma, Dorret I.; Hottenga, Jouke-Jan; Willemsen, Gonneke; Penninx, Brenda W. J. H.; Nolte, Ilja M.; de Geus, Eco J. C.; Wang, Xiaoling; Snieder, Harold
Heart rate variability is an important risk factor for cardiovascular disease and all-cause mortality. The acetylcholine pathway plays a key role in explaining heart rate variability in humans. We assessed whether 443 genotyped and imputed common genetic variants in eight key genes (CHAT, SLC18A3, SLC5A7, CHRNB4, CHRNA3, CHRNA, CHRM2 and ACHE) of the acetylcholine pathway were associated with variation in an established measure of heart rate variability reflecting parasympathetic control of the heart rhythm, the root mean square of successive differences (RMSSD) of normal RR intervals. The association was studied in a two stage design in individuals of European descent. First, analyses were performed in a discovery sample of four cohorts (n?=?3429, discovery stage). Second, findings were replicated in three independent cohorts (n?=?3311, replication stage), and finally the two stages were combined in a meta-analysis (n?=?6740). RMSSD data were obtained under resting conditions. After correction for multiple testing, none of the SNPs showed an association with RMSSD. In conclusion, no common genetic variants for heart rate variability were identified in the largest and most comprehensive candidate gene study on the acetylcholine pathway to date. Future gene finding efforts for RMSSD may want to focus on hypothesis free approaches such as the genome-wide association study. PMID:25384021
Uusitalo, Arja; Mets, Terhi; Martinmäki, Kaisu; Mauno, Saija; Kinnunen, Ulla; Rusko, Heikki
Changes in autonomic nervous system function have been related to work stress induced increases in cardiovascular morbidity and mortality. Our purpose was to examine whether various heart rate variability (HRV) measures and new HRV-based relaxation measures are related to self-reported chronic work stress and daily emotions. The relaxation measures are based on neural network modelling of individual baseline heart rate and HRV information. Nineteen healthy hospital workers were studied during two work days during the same work period. Daytime, work time and night time heart rate, as well as physical activity were recorded. An effort-reward imbalance (ERI) questionnaire was used to assess chronic work stress. The emotions of stress, irritation and satisfaction were assessed six times during both days. Seventeen subjects had an ERI ratio over 1, indicating imbalance between effort and reward, that is, chronic work stress. Of the daily emotions, satisfaction was the predominant emotion. The daytime relaxation percentage was higher on Day 2 than on Day 1 (4 ± 6% vs. 2 ± 3%, p < 0.05) and the night time relaxation (43 ± 30%) was significantly higher than daytime or work time relaxation on the both Days. Chronic work stress correlated with the vagal activity index of HRV. However, effort at work had many HRV correlates: the higher the work effort the lower daytime HRV and relaxation time. Emotions at work were also correlated with work time (stress and satisfaction) and night time (irritation) HRV. These results indicate that daily emotions at work and chronic work stress, especially effort, is associated with cardiac autonomic function. Neural network modelling of individual heart rate and HRV information may provide additional information in stress research in field conditions. PMID:21356531
Juan F. Ramirez-Villegas; Eric Lam-Espinosa; David F. Ramirez-Moreno; Paulo C. Calvo-Echeverry; Wilfredo Agredo-Rodriguez; Kelvin Wong
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).
Renza Perini; Stefania Milesi; Luca Biancardi; David R. Pendergast; Arsenio Veicsteinas
Power spectrum analysis of heart-rate variability was made in seven men [mean age 22 (SEM 1) years] in head-out water immersion\\u000a (W) and in air (A, control) at rest and during steady-state cycling to maximal intensity (maximum oxygen uptake, V?O2max). At rest W resulted in a trebled increase in the total power (P?0.05), coupled with minimal changes in the power
Tugnoli, V; Cristofori, M C; Serra, G; Manca, M; Eleopra, R; Bottoni, M
Sinus arrhythmia (SA) is a physiological event related to the respiratory activity. The aim of this study was to find a relation between SA and different deep breathings. A transductor monitored the chest respiratory movements and a cardiotachometer calculated and plotted the instantaneous heart rate, synchronously during different breathing efforts. In 10 normal subjects a good linear correlation was found between the breathing depth and SA quantifying the relation between the chest receptor activity and SA also with limited chest expansion. PMID:6466470
Patrick J. O'Connor; Michael A. Crowley; Andrew W. Gardner; James S. Skinner
Summary The purpose of this investigation was to examine the influence of daytime exercise on heart rate during sleep. Nine, untrained male college students volunteered to participate. They cycled at 75% maximum oxygen uptake, (\\u000a$$\\\\dot V$$\\u000aO2max) 30 min·day–1 for 12 weeks. The exercise duration was increased by 5 min every 4 weeks from 30 to 40 min per session.
Zhang, Chong; Yu, Xiaolin
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.
Kaur, Balvinder; Durek, Joseph J.; O'Kane, Barbara L.; Tran, Nhien; Moses, Sophia; Luthra, Megha; Ikonomidou, Vasiliki N.
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 , ,  & . Recent work has shown that some of the HRV features can potentially be used for distinguishing a subject's normal mental state from a stressed one ,  & . In all of these past works, although processing is done in both frequency and time domains, few classification algorithms have been explored for classifying normal from stressed RRintervals. In this paper we used 30 s intervals from the Electrocardiogram (ECG) time series collected during normal and stressed conditions, produced by means of a modified version of the Trier social stress test, to compute HRV-driven features and subsequently applied a set of classification algorithms to distinguish stressed from normal conditions. To classify RR-intervals, we explored classification algorithms that are commonly used for medical applications, namely 1) logistic regression (LR)  and 2) linear discriminant analysis (LDA) . Classification performance for various levels of stress over the entire test was quantified using precision, accuracy, sensitivity and specificity measures. Results from both classifiers were then compared to find an optimal classifier and HRV features for stress detection. This work, performed under an IRB-approved protocol, not only provides a method for developing models and classifiers based on human data, but also provides a foundation for a stress indicator tool based on HRV. Further, these classification tools will not only benefit many civilian applications for detecting stress, but also security and military applications for screening such as: border patrol, stress detection for deception ,, and wounded-warrior triage .
Velimirovic, D B; Pavlovic, S U; Petrovic, P; Neskovic, A; Zivkovic, M; Bojic, M
We have presently demonstrated that when added to mitral valve replacement (MVR) the corridor procedure is 75% efficient in restoring and maintaining sinus rhythm in patients with chronic atrial fibrillation (AF), caused by rheumatic mitral valve disease, (follow up 13.9months). In the same patient population, we observed that the typical day-night cycle heart rate (HR) variations were lost and our present study concentrates on this subject. Heart rate variability analysis based on 24-h Holter ECG recording (StrataScan 563 DelMar Avionics) or hospital discharge (12th-14th postoperative days) was performed in 3 patient groups: Group I: Patients with a Corridor procedure added to MVR (12pts, m/f 10/2, mean age 47.3+/-7.5yr); Group II (control): with patients MVR performed through the left atrial approach, without additional antiarrhythmic procedures (10pts, m/f 3/7 mean age 51.5+/-6.7yr), and Group III: heart transplant recipients (5pts, mean age 46.4+/-11.22yr). We analyzed the hourly heart rate over 24-h period divided into three 8-h segments (07-14h; 15-22h and 23-06h). Statistical comparison of mean hourly heart rate values was made between the three time periods of Holter monitoring. The Corridor procedure performed with mitral valve replacement resulted in conversion of sinus rhythm in 75% of patients (Group I), but postoperative heart rate variability analyses based on Holter monitoring disclosed that the mean heart rate was not statistically significantly difficult between the three 8-h segments of the day-night (P>0.05). The same results were found in the group of patients after heart transplant (P>0.05). The same results were found in the group of patients after heart transplant (P>0.05). In the second group (classical MVR), statistically significant differences in mean HR variation existed between the three 8-h intervals (P<0.05), and although atrial fibrillation occurred postoperatively physiologic circadian heart rate variations were preserved. With the Corridor procedure, both atria were surgically and electrically isolated and chronotropic function of the ventricles was restored by creating a small strip of atrial tissue with isolated sinus node and atrio-ventricular node, connected to the ventricles. This technique produced heart denervation nervous system influence, producing the loss of circadian HR variations, similar to the transplanted heart. PMID:11137811
The heart beat data recorded from samples before and during meditation are analyzed using two different scaling analysis methods. These analyses revealed that mediation severely affects the long range correlation of heart beat of a normal heart. Moreover, it is found that meditation induces periodic behavior in the heart beat. The complexity of the heart rate variability is quantified using multiscale entropy analysis and recurrence analysis. The complexity of the heart beat during mediation is found to be more.
Dario DiFrancesco; John A. Camm
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
Compostella, Leonida; Russo, Nicola; D’Onofrio, Augusto; Setzu, Tiziana; Compostella, Caterina; Bottio, Tomaso; Gerosa, Gino; Bellotto, Fabio
Introduction Complete denervation of transplanted heart exerts protective effect against postoperative atrial fibrillation; various degrees of autonomic denervation appear also after transection of ascending aorta during surgery for aortic aneurysm. Objective This study aimed to evaluate if the level of cardiac denervation obtained by resection of ascending aorta could exert any effect on postoperative atrial fibrillation incidence. Methods We retrospectively analysed the clinical records of 67 patients submitted to graft replacement of ascending aorta (group A) and 132 with aortic valve replacement (group B); all episodes of postoperative atrial fibrillation occurred during the 1-month follow-up have been reported. Heart Rate Variability parameters were obtained from a 24-h Holter recording; clinical, echocardiographic and treatment data were also evaluated. Results Overall, 45% of patients (group A 43%, group B 46%) presented at least one episode of postoperative atrial fibrillation. Older age (but not gender, abnormal glucose tolerance, ejection fraction, left atrial diameter) was correlated with incidence of postoperative atrial fibrillation. Only among a subgroup of patients with aortic transection and signs of greater autonomic derangement (heart rate variability parameters below the median and mean heart rate over the 75th percentile), possibly indicating more profound autonomic denervation, a lower incidence of postoperative atrial fibrillation was observed (22% vs. 54%). Conclusion Transection of ascending aorta for repair of an aortic aneurysm did not confer any significant protective effect from postoperative atrial fibrillation in comparison to patients with intact ascending aorta. It could be speculated that a limited and heterogeneous cardiac denervation was produced by the intervention, creating an eletrophysiological substrate for the high incidence of postoperative atrial fibrillation observed. PMID:25859868
B. Stanek; W. Reiterer; P. Placheta; G. Raberger
The effects of a single dose of alinidine (0.5 mg\\/kg i.v.), the N-allyl-derivative of clonidine, on heart rate and blood pressure were investigated in healthy volunteers and in patients with hyperkinetic heart syndrome, at rest and during bicycle exercise. In healthy volunteers plasma catecholamine levels were also determined. Alinidine did not change heart rate at rest in the healthy volunteers
Philippe P. Lechat
Large randomized trials have demonstrated that beta-blocker treatment reduces morbidity and mortality in patients in chronic heart failure. Questions remain about the influence of individual characteristics on the magnitude of the benefit of beta-blockers in patients with heart failure including the influence of heart rate and cardiac rhythm. In the Cardiac Insufficiency Bisoprolol Study II, baseline heart rate and heart
Joris Lefever; Daniel Berckmans; Jean-Marie Aerts
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
Mardi L. Sait; Andrew W. Wood; Hassan A. Sadafi
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
den Hoed, Marcel; Eijgelsheim, Mark; Esko, Tőnu; Brundel, Bianca J J M; Peal, David S; Evans, David M; Nolte, Ilja M; Segrč, 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, Sřren; 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, Ĺsa; 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
Elevated resting heart rate is associated with greater risk of cardiovascular disease and mortality. In a 2-stage meta-analysis of genome-wide association studies in up to 181,171 individuals, we identified 14 new loci associated with heart rate and confirmed associations with all 7 previously established loci. Experimental downregulation of gene expression in Drosophila melanogaster and Danio rerio identified 20 genes at 11 loci that are relevant for heart rate regulation and highlight a role for genes involved in signal transmission, embryonic cardiac development and the pathophysiology of dilated cardiomyopathy, congenital heart failure and/or sudden cardiac death. In addition, genetic susceptibility to increased heart rate is associated with altered cardiac conduction and reduced risk of sick sinus syndrome, and both heart rate–increasing and heart rate–decreasing variants associate with risk of atrial fibrillation. Our findings provide fresh insights into the mechanisms regulating heart rate and identify new therapeutic targets. PMID:23583979
den Hoed, Marcel; Eijgelsheim, Mark; Esko, Tőnu; Brundel, Bianca J J M; Peal, David S; Evans, David M; Nolte, Ilja M; Segrč, 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; den Heijer, Martin; 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; St Pourcain, Beate; 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, Sřren; 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, Asa; 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; Mateo Leach, Irene; 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; Newton-Cheh, Christopher; Ellinor, Patrick T; Stricker, Bruno H Ch; Metspalu, Andres; Perola, Markus
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
Liu, Chengyu; Li, Ke; Zhao, Lina; Liu, Feng; Zheng, Dingchang; Liu, Changchun; Liu, Shutang
This paper proposed a new entropy measure, Fuzzy Measure Entropy (FuzzyMEn), for the analysis of heart rate variability (HRV) signals. FuzzyMEn was calculated based on the fuzzy set theory and improved the poor statistical stability in the approximate entropy (ApEn) and sample entropy (SampEn). The simulation results also demonstrated that the FuzzyMEn had better algorithm discrimination ability when compared with the recently published fuzzy entropy (FuzzyEn), The validity of FuzzyMEn was tested for clinical HRV analysis on 120 subjects (60 heart failure and 60 healthy control subjects). It is concluded that FuzzyMEn could be considered as a valid and reliable method for a clinical HRV application. PMID:23273774
Lon?ar-Turukalo, T; Vasi?, M; Tasi?, T; Mijatovi?, G; Glumac, S; Baji?, D; Japunži?-Žigon, N
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
Makowiec, D.; Rynkiewicz, A.; Ga?aska, R.; Wdowczyk-Szulc, J.; ?arczy?ska-Buchowiecka, M.
The method of effective reading of multifractal properties is proposed. The method consists in the analysis of a given signal together with the analysis of an integrated signal. A practical way to separate monofractal-type signals from other signals is given. The method is applied to 24-hour ECG recordings of RR-interbeat intervals to assess the effect of aging on autonomic regulation of the heart in healthy adults. Heart rate variability is evaluated by multifractal analysis in the VLF band. A switch from mono- to multifractality is observed between diurnal and nocturnal parts of series in the group of young adults. With aging the multifractal structure of nocturnal signals declines. The observed changes can be related to the circadian alternation in the central mechanisms controlling the cardiovascular system which becomes impaired with advance in age in human. Indices for age impairment of autonomic regulation are proposed.
Hu, Jing; Gao, Jianbo; Tung, Wen-wen
Previous studies on heart rate variability (HRV) using chaos theory, fractal scaling analysis, and many other methods, while fruitful in many aspects, have produced much confusion in the literature. Especially the issue of whether normal HRV is chaotic or stochastic remains highly controversial. Here, we employ a new multiscale complexity measure, the scale-dependent Lyapunov exponent (SDLE), to characterize HRV. SDLE has been shown to readily characterize major models of complex time series including deterministic chaos, noisy chaos, stochastic oscillations, random 1/f processes, random Levy processes, and complex time series with multiple scaling behaviors. Here we use SDLE to characterize the relative importance of nonlinear, chaotic, and stochastic dynamics in HRV of healthy, congestive heart failure, and atrial fibrillation subjects. We show that while HRV data of all these three types are mostly stochastic, the stochasticity is different among the three groups.
Adrian M. Walker; J. Cannata; Margaret H. Dowling; Blair Ritchie; John E. Maloney
Development of autonomic nervous control of basal heart rate was studied in unanesthetized fetal lambs (93 days to term) and newborn lambs (2–29 days), using atropine and\\/or propranolol blockade. Fetal lambs showed a progressive increase in parasympathetic restraint of heart rate; vagal influence in the newborn lamb was similar to the term fetus. Sympathetic stimulation of fetal heart rate declined
GERALD L. KOOYMAN; PAUL J. PONGANIS; MICHAEL A. CASTELLINI; EDWARD P. PONGANIS; KATHERINE V. PONGANIS; PHILIP H. THORSONM; SCOTT A. ECKERT; YVON LEMAHO
Summary Heart rate during overnight rest and while diving were recorded from five emperor penguins with a microprocessor-controlled submersible recorder. Heart rate, cardiac output and stroke volume were also measured in two resting emperor penguins using standard electrocardiography and thermodilution measurements. Swim velocities from eight birds were obtained with the submersible recorder. The resting average of the mean heart rates
McSharry, Patrick E.
to a range of disorders including congestive heart failure, stroke, myocardial infarction and kidney failureConfronting 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
McSharry, Patrick E.
to a range of disorders including congestive heart failure, stroke, myocardial infarction and kidney failureConfronting 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
Cooper, Robin L.
Video Article Measures of Heart and Ventilatory Rates in Freely Moving Crayfish Sonya M. Bierbower: Bierbower S.M., Cooper R.L. (2009). Measures of Heart and Ventilatory Rates in Freely Moving Crayfish. Jo. Crayfish are good model organisms for heart and ventilatory rate measurements due to the feasibility
ORIGINAL PAPER Environment and feeding change the ability of heart rate to predict metabolism 2010 / Published online: 12 August 2010 Ó Springer-Verlag 2010 Abstract The ability to use heart rate of physiological, behavioral, and environmental states. Keywords Steller sea lion Á Heart rate Á Oxygen consumption
ORIGINAL PAPER Environment and feeding change the ability of heart rate to predict metabolism 2010 Ó Springer-Verlag 2010 Abstract The ability to use heart rate (fh) to predict oxygen consumption, and environmental states. Keywords Steller sea lion Á Heart rate Á Oxygen consumption Á Heat increment of feeding Á
Hao Liu; Jun Hu; Matthias Rauterberg
Travel by air, especially long distance, the enclosed environment of the aircraft cabin causes discomfort and even stress to flight passengers. In this paper, we present a new heart rate controlled music recommendation system. Heart rate is used as a stress indicator. If the user is stressed and his\\/her heart rate is higher\\/lower than normal, the system recommends a user
Sandman, Curt A.; Wadhwa, Pathik; Hetrick, William; Porto, Manuel; Peeke, Harmon V. S.
Examined the ability of 32-week human fetuses to learn and recall information. Found a significant heart rate habituation pattern for a series of vibroacoustic stimuli. After a single novel stimulus, the heart rate to stimulus 1 reemerged. Uterine contractions were not related to presentation of the novel stimulus or change in heart rate after the…
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
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
M. G. Sparrow; H. Roggendorf; W. H. Vogel
The effect of ethanol on the cardiovascular system (ECG, heart rate, blood pressure) was studied in anesthetized, nonstressed or stressed rats. In anesthetized rats, ethanol showed no effect on heart rate or ECG. In nonstressed rats, ethanol sedated the animals but increased heart rate significantly. This ethanol induced tachycardia seemed the result of a direct stimulation of the sympathetic nerves
HEART RATE AND BLOOD PRESSURE VARIABILITY UNDER MOON, MARS AND ZERO GRAVITY CONDITIONS DURING via the heart rate variability (HRV) and blood pressure variability (BPV). HRV and BPV were assessed in this study to assess the heart rate variability (HRV) and blood pres- sure variability (BPV). Due to gravity
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 to reduce postflight orthostatic intolerance. Key words: parabolic flight; heart rate; blood pressure
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
Paris-Sud XI, Université de
Neonatology. Author manuscript Page /1 7 Uncorrelated Randomness of the Heart Rate Is Associated markers are needed. Objectives It was the aim of this study to determine if heart rate (HR) behavior may Keywords Bacterial infection ; Computer-assisted diagnosis ; Heart rate variability ; Sepsis Introduction
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
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
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
Ha, Amy Sau-ching; Heung-Sang Wong, Stephen
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.…
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
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
Large deviations estimates for the multiscale analysis of heart rate variability$,$$ Patrick to characterize relevant physiological factors impacting the heart rate variability. Notwithstanding. In this article, we illustrate the relevance of this approach, on both theoretical objects and on human heart rate
Reliability and Accuracy of Heart Rate Variability Metrics Versus ECG Segment Duration J. McNames1, Oregon Health & Science University, Portland, OR, USA Abstract-- Heart rate variability (HRV) has been used in many studies to assess the effects of autonomic regulation on the heart rate. A 1996 task force
Sánchez, Angel "Anxo"
Analysis of Physiological Meaning of Detrended Fluctuation Analysis in Heart Rate Variability Using Fluctuation Analysis (DFA), have been widely used for quantifying the Heart Rate Variability (HRV) for cardiac lumped parameter models. 1. Introduction During the last years, Heart Rate Variability (HRV) sig- nal has
Paris-Sud XI, Université de
and resting heart rate on mortality: the Whitehall II prospective cohort study Hermann Nabi 1 2 * , Mika Kivim symptoms and resting heart rate (RHR) on mortality. Methods Data come from 5936 participants, aged 61 6 improve survival. Author Keywords depression ; resting heart rate and mortality INTRODUCTION Depression
Stress Classification by Separation of Respiratory Modulations in Heart Rate Variability using of respiration on the heart rate is a phenomenon known as respiratory sinus arrhythmia. However, effects of respiration are often ignored in studies of heart rate variability. In this paper, we take respiratory
Multifractal Analysis of Fetal Heart Rate Variability in Fetuses with and without Severe Acidosis multifractal analysis of fetal heart rate (FHR) variability in fetuses with and without acidosis during labor and nonacidotic fetuses, independently from FHR pattern. KEYWORDS: Acidosis, fetal heart rate, labor, multifractal
Large deviations estimates for the multiscale analysis of heart rate variability$,$$ 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
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
Sensitivity of detrended fluctuation analysis applied to heart rate variability of preterm firstname.lastname@example.org 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
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
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
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
Paris-Sud XI, Université de
Time-Frequency Relationships between Heart Rate and Respiration: A Diagnosis Tool for Late Onset of the laboratory tests, including CRP and blood culture, have high predictive accuracy. Heart rate variability (HRV. The objective of this study was to determine if analysis of time-frequency correlations between the heart rate
A Robust Method to Estimate Instantaneous Heart Rate from Noisy Electrocardiogram Waveforms ANDREI for real-time esti- mation of instantaneous heart rate (HR) from noise-laden electrocardiogram (ECG of instantaneous heart rate (HR) is one of the most vexing problems in physiological measurements.4
Paris-Sud XI, Université de
Uncorrelated Randomness of the Heart Rate Is Associated with Sepsis in Sick Premature Infants Alain.1159/000208792 Key Words Bacterial infection Computer-assisted diagnosis Heart rate variability Sepsis Abstract are needed. Objectives: It was the aim of this study to determine if heart rate (HR) behavior may help
In vivo cardiac phase response curve elucidates human respiratory heart rate variability Published-related variation of the heart rate by S. Hales in 1733 and its first registration by C. Ludwig in 1847 , cardio of heart rate variability has become important in many medical fields as a diagnostically
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
Makikallio, T. H.; Seppanen, T.; Airaksinen, K. E.; Koistinen, J.; Tulppo, M. P.; Peng, C. K.; Goldberger, A. L.; Huikuri, H. V.
Dynamics analysis of RR interval behavior and traditional measures of heart rate variability were compared between postinfarction patients with and without vulnerability to ventricular tachyarrhythmias in a case-control study. Short-term fractal correlation of heart rate dynamics was better than traditional measures of heart rate variability in differentiating patients with and without life-threatening arrhythmias.
Amy M. Hayes; Jonathan N. Myers; Monica Ho; Matthew Y. Lee; Inder Perkash; B. Jenny Kiratli
This study evaluated the accuracy of heart rate calibrated from a maximum exercise test for predicting energy expenditure during five activities of daily living (ADL) in par- ticipants with spinal cord injury (SCI). Thirteen individuals with SCI underwent maximum exercise testing, followed by portable heart rate and metabolic testing during five ADL. A regression equation was developed from heart rate
Wilhelmina E. M. Spinnewijn; Frederik K. Lotgering; Piet C. Struijk; Henk C. S. Wallenburg
OBJECTIVE: Our aim was to assess the physiologic response of human fetal heart rate and uterine contractility to moderately strenuous maternal exercise. STUDY DESIGN: We measured fetal heart rate and intrauterine pressure with the use of internal monitoring before, during, and after maternal exercise at a heart rate of 140 beats\\/min on a cycle ergometer in 30 term women admitted
Corotto, Frank; Ceballos, Darrel; Lee, Adam; Vinson, Lindsey
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…
Bimmel, Nicole; van IJzendoorn, Marinus H.; Bakermans-Kranenburg, Marian J.; Juffer, Femmie; De Geus, Eco J. C.
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…
Laurson, Kelly R.; Brown, Dale D.; Cullen, Robert W.; Dennis, Karen K.
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…
Hui, Stanley Sai-chuen; Chan, Janus Wan-sze
The purpose of the present study was to examine the relationship between oxygen uptake (VO[subscript 2]) and heart rate (HR) responses during rest and exercise in Chinese children and youth and to evaluate the relationships between maximal heart rate (%HRmax), heart rate reserve (%HRR), peak oxygen uptake (%VO[subscript 2]peak), and oxygen uptake…
O. G. Shpuga
The rate of heart contractions, electric-skin and vascular reactions to different agents exciting and inhibiting the rate of heart contractions have been studied in patients with coronary insufficiency. A diminished ability to alter the rate of the heart rhythm has been disclosed in such patients. Since no specific peculiarities have been demonstrated in the reactions of other negatative functions, it
Alan D. Moore; Stuart M. C. Lee; Michael C. Greenisen; Phillip Bishop
Accurate heart rate measurement during work is required for many industrial hygiene and ergonomics situations. The purpose of this investigation was to determine the validity of heart rate measurements obtained by a simple, lightweight, commercially available, wrist-worn heart rate monitor (HRM) during work (cycle exercise) sessions conducted in the laboratory and also during the particularly challenging work environment of space
Chan, Alexander M; Selvaraj, Nandakumar; Ferdosi, Nima; Narasimhan, Ravi
Unobtrusive continuous monitoring of important vital signs and activity metrics has the potential to provide remote health monitoring, at-home screening, and rapid notification of critical events such as heart attacks, falls, or respiratory distress. This paper contains validation results of a wireless Bluetooth Low Energy (BLE) patch sensor consisting of two electrocardiography (ECG) electrodes, a microcontroller, a tri-axial accelerometer, and a BLE transceiver. The sensor measures heart rate, heart rate variability (HRV), respiratory rate, posture, steps, and falls and was evaluated on a total of 25 adult participants who performed breathing exercises, activities of daily living (ADLs), various stretches, stationary cycling, walking/running, and simulated falls. Compared to reference devices, the heart rate measurement had a mean absolute error (MAE) of less than 2 bpm, time-domain HRV measurements had an RMS error of less than 15 ms, respiratory rate had an MAE of 1.1 breaths per minute during metronome breathing, posture detection had an accuracy of over 95% in two of the three patch locations, steps were counted with an absolute error of less than 5%, and falls were detected with a sensitivity of 95.2% and specificity of 100%. PMID:24111135
Ay?ehan Akinci; Alpay Çeliker; Engin Baykal; Tahsin Teziç
Heart rate variability (HRV) is a noninvasive index of the neural activity of the heart. Although also influenced by the sympathetic activity of the heart, HRV is essentially determined by the vagal stimulation of the heart. Several HRV abnormalities have been described in adults with diabetes mellitus. However, there are few data on HRV in children with diabetes mellitus. In
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
Cowings, P. S.
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.
Pahlevan, Niema; Gharib, Morteza
The workload on the left ventricle is composed of steady and pulsatile components. Clinical investigations have confirmed that an abnormal pulsatile load plays an important role in the pathogenesis of left ventricular hypertrophy (LVH) and progression of LVH to congestive heart failure (CHF). The pulsatile load is the result of the complex dynamics of wave propagation and reflection in the compliant arterial vasculature. We hypothesize that aortic waves can be optimized to reduce the left ventricular (LV) pulsatile load. We used an in-vitro experimental approach to investigate our hypothesis. A unique hydraulic model was used for in-vitro experiments. This model has physical and dynamical properties similar to the heart-aorta system. Different compliant models of the artificial aorta were used to test the hypothesis under various aortic rigidities. Our results indicate that: i) there is an optimum heart rate that minimizes LV pulsatile power (this is in agreement with our previous computational study); ii) introducing an extra reflection site at the specific location along the aorta creates constructive wave conditions that reduce the LV pulsatile power.
Ozveren, Olcay; Dogdu, Orhan; Sengul, Cihan; Cinar, Veysel; Eroglu, Elif; Kucukdurmaz, Zekeriya; Degertekin, Muzaffer
Background Non-alcoholic fatty liver disease (NAFLD) has been considered as a benign disease often associated with central obesity and insulin resistance and, in general, with factors of the metabolic syndrome. Heart rate recovery after exercise is a function of vagal reactivation, and its impairment is an independent prognostic indicator for cardiovascular and all-cause mortality. The aim of our study was to evaluate the heart rate recovery index in patients with NAFLD. Material/Methods The study population included 59 patients with NAFLD (mean age=42.3±9.3 years) and 22 healthy subjects as controls (mean age=40.7±6.5 years). Basal electrocardiography, echocardiography, and treadmill exercise testing were performed on all patients and controls. The heart rate recovery index was defined as the reduction in the heart rate from the rate at peak exercise to the rate at the 1st minute (HRR1), 2nd minute (HRR2), 3rd minute (HRR3), and 5th minute (HRR5) after stopping exercise stress testing. Results There were significant differences in HRR1 and HRR2 indices between patients with ED and the control group (19.9±8.2 vs. 34.1±9.6; p<0.001 and 24.3±5.4 vs. 40.5±9.1; p=0.006, respectively). Similarly, HRR indices after the 3rd and 5th minutes of the recovery period were significantly lower in patients with NAFLD compared with those indices in the control group (32.3±8.5 vs. 58.4±6.5; p=0.001 and 58±18.2 vs. 75.1±15.8; p<0.001). Effort capacity was markedly lower (11±1.9 vs. 12.5±1.5 METs; p=0.001) among the patients with NAFLD. Conclusions The heart rate recovery index is deteriorated in patients with NAFLD. When the prognostic significance of the heart rate recovery index is considered, these results may help explain the increased occurrence of cardiac death. It points to the importance of the heart rate recovery index in the identification of high-risk patients. PMID:25168159
Streeby, D R; McKean, T A
Muskrats (Ondontra zibethicus) are common freshwater diving mammals exhibiting a bradycardia with both forced and voluntary diving. This bradycardia is mediated by vagal innervation; however, if hypoxia is present there may be local factors that also decrease heart rate. Some of these local factors may include ATP-sensitive potassium channel activation and extracellular accumulation of potassium ions, hydrogen ions and lactate. The purpose of this study was to investigate the role of these factors in the isolated perfused hearts of muskrats and of a non-diving mammal, the guinea pig. Although lactate and proton administration reduced heart rate in isolated muskrat and guinea pig hearts, there was no difference in the response to lactate and proton infusion between the two species. Muskrat hearts were more sensitive to the heart-rate-lowering effects of exogenously applied potassium than were guinea pig hearts. Early increases in extracellular potassium concentration during hypoxia are thought to be mediated by the ATP-sensitive potassium channel. Activation of these channels under normoxic conditions had a mildly negative chronotropic effect in both species; however, activation of these channels with Lemakalim under hypoxic conditions caused the guinea pig heart to respond with an augmented bradycardia similar to that seen in the hypoxic muskrat heart in the absence of drugs. Inhibition of these channels by glibenclamide during hypoxia was partially successful in blocking the bradycardia in guinea pig hearts, but inhibition of the same channels in hypoxic muskrat hearts had a damaging effect as two of five hearts went into contracture during the hypoxia. Thus, although ATP-sensitive potassium channels appear to have a major role in the bradycardia of hypoxia in guinea pigs, the failure to prevent the bradycardia by inhibition of these channels in muskrat hearts suggests that multiple factors are involved in the hypoxia-induced bradycardia in this species. PMID:7852900
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
Dolbow, David R; Farley, Richard S; Kim, Jwa K; Caputo, Jennifer L
The purpose of this study was to examine the cardiovascular responses to water treadmill walking at 2.0 mph (3.2 km/hr), 2.5 mph (4.0 km/hr), and 3.0 mph (4.8 km/hr) in older adults. Responses to water treadmill walking in 92 degrees F (33 degrees C) water were compared with responses to land treadmill walking at 70 degrees F (21 degrees C) ambient temperature. After an accommodation period, participants performed 5-min bouts of walking at each speed on 2 occasions. Oxygen consumption (VO2), heart rate (HR), systolic blood pressure (SBP), and rating of perceived exertion (RPE) were significantly higher during therapeutic water treadmill walking than during land treadmill walking. Furthermore, VO2, HR, and RPE measures significantly increased with each speed increase during both land and water treadmill walking. SBP significantly increased with each speed during water treadmill walking but not land treadmill walking. Thus, it is imperative to monitor HR and blood pressure for safety during this mode of activity for older adults. PMID:18212391
Ming Xin Qin; Yi Min Zang; Xue Tao Shi; Feng Fu
This paper presents the concept of the short-time nonlinear dynamical analysis of heart rate variability for physiological animal experiments and pharmacological experiments as well as clinical diagnosis and prognosis. We established an animal experiment protocol of myocardial ischemia to observe the results of the short-time nonlinear dynamical analysis of heart rate variability and compared the nonlinear dynamical parameters of heart
Kristine K Hicks; Ernst Seifen; Joseph R Stimers; Richard H Kennedy
Diabetes-associated alterations in resting heart rate and blood pressure have been demonstrated in clinical studies and in animal models of insulin-dependent diabetes mellitus (IDDM). These alterations may result from changes in the heart, vasculature or autonomic nervous system control. Using the streptozotocin- (STZ-) treated rat model of IDDM, the current study was designed to: (1) monitor changes in heart rate
minutes; then, after the supine heart rate and blood pressure are obtained, the patient is tilted using Head Up Tilt (HUT) test can be used to evaluate how human body regulates blood pressure and heartSpectral and symbolic analysis of Heart Rate data during Tilt Test Camillo Cammarota Enrico Rogora
Krzysztof Narkiewicz; Virend K. Somers
Background—Sympathetic traffic to the peripheral vasculature and sympathetic discharge to the heart have complemen- tary effects on blood pressure. Although faster heart rates have been linked to higher blood pressures, the relationship between muscle sympathetic nerve activity (MSNA) and long-term regulation of blood pressure is not clear. We tested the hypothesis that MSNA and heart rate are linked to blood
AKIKO NONAKA; HIDEYUKI SHIOTANI; KIMIKO KITANO; MITSUHIRO YOKOYAMA
Background: Heart rate recovery after exercise is an independent prognostic indicator for cardiovascular and all-cause mortality. The purpose of this study was to clarify the clinical determinants of heart rate recovery. Methods and results: We examined 114 consecutive male patients who underwent exercise myocardial perfusion single-photon emission computed tomography and echocardiography for the evaluation of suspected coronary artery disease. Heart
Gardim, Camila Balsamo; de Oliveira, Bruno Affonso P.; Bernardo, Aline Fernanda B.; Gomes, Rayana Loch; Pacagnelli, Francis Lopes; Lorençoni, Roselene Modolo R.; Vanderlei, Luiz Carlos M.
OBJECTIVE: To gather current information about the effects of type 1 diabetes mellitus on children's cardiac autonomic behavior. DATA SOURCES: The search of articles was conducted on PubMed, Ibecs, Medline, Cochrane, Lilacs, SciELO and PEDro databases using the MeSH terms: "autonomic nervous system", "diabetes mellitus", "child", "type 1 diabetes mellitus", "sympathetic nervous system" and "parasympathetic nervous system", and their respective versions in Portuguese (DeCS). Articles published from January 2003 to February 2013 that enrolled children with 9-12 years old with type 1 diabetes mellitus were included in the review. DATA SYNTHESIS: The electronic search resulted in four articles that approached the heart rate variability in children with type 1 diabetes mellitus, showing that, in general, these children present decreased global heart rate variability and vagal activity. The practice of physical activity promoted benefits for these individuals. CONCLUSIONS: Children with type 1 diabetes mellitus present changes on autonomic modulation, indicating the need for early attention to avoid future complications in this group. PMID:25119762
Henry, Brook L.; Minassian, Arpi; Perry, William
Background Methamphetamine (METH) is an increasing popular and highly addictive stimulant associated with autonomic nervous system (ANS) dysfunction, cardiovascular pathology, and neurotoxicity. Heart rate variability (HRV) has been used to assess autonomic function and predict mortality in cardiac disorders and drug intoxication, but has not been characterized in METH use. We recorded HRV in a sample of currently abstinent individuals with a history of METH dependence compared to age- and gender-matched drug-free comparison subjects. Method HRV was assessed using time domain, frequency domain, and nonlinear entropic analyses in 17 previously METH-dependent and 21 drug-free comparison individuals during a 5 minute rest period. Results The METH-dependent group demonstrated significant reduction in HRV, reduced parasympathetic activity, and diminished heartbeat complexity relative to comparison participants. More recent METH use was associated with increased sympathetic tone. Conclusion Chronic METH exposure may be associated with decreased HRV, impaired vagal function, and reduction in heart rate complexity as assessed by multiple methods of analysis. We discuss and review evidence that impaired HRV may be related to the cardiotoxic or neurotoxic effects of prolonged METH use. PMID:21182570
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
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
Diller, James W; Patros, Connor H G; Prentice, Paula R
Temporal discounting is the reduction of the value of a reinforcer as a function of increasing delay to its presentation. Impulsive individuals discount delayed consequences more rapidly than self-controlled individuals, and impulsivity has been related to substance abuse, gambling, and other problem behaviors. A growing body of literature has identified biological correlates of impulsivity, though little research to date has examined relations between delay discounting and markers of poor health (e.g., cardiovascular reactivity to stress). We evaluated the relation between one aspect of impulsivity, measured using a computerized temporal discounting task, and heart rate reactivity, measured as a change in heart rate from rest during a serial subtraction task. A linear regression showed that individuals who were more reactive to stress responded more impulsively (i.e., discounted delayed reinforcers more rapidly). When results were stratified by gender, the effect was observed for females, but not for males. This finding supports previous research on gender differences in cardiovascular reactivity and suggests that this type of reactivity may be an important correlate of impulsive behavior. PMID:21601618
Voicu, Iulian; Girault, Jean-Marc; Roussel, Catherine; Decock, Aliette; Kouame, Denis
Introduction: In utero, Monitoring of fetal wellbeing or suffering is today an open challenge, due to the high number of clinical parameters to be considered. An automatic monitoring of fetal activity, dedicated for quantifying fetal wellbeing, becomes necessary. For this purpose and in a view to supply an alternative for the Manning test, we used an ultrasound multitransducer multigate Doppler system. One important issue (and first step in our investigation) is the accurate estimation of fetal heart rate (FHR). An estimation of the FHR is obtained by evaluating the autocorrelation function of the Doppler signals for ills and healthiness foetus. However, this estimator is not enough robust since about 20% of FHR are not detected in comparison to a reference system. These non detections are principally due to the fact that the Doppler signal generated by the fetal moving is strongly disturbed by the presence of others several Doppler sources (mother' s moving, pseudo breathing, etc.). By modifying the existing method (autocorrelation method) and by proposing new time and frequency estimators used in the audio' s domain, we reduce to 5% the probability of non-detection of the fetal heart rate. These results are really encouraging and they enable us to plan the use of automatic classification techniques in order to discriminate between healthy and in suffering foetus.
Pinheiro, Eduardo C; Postolache, Octavian A; Girăo, Pedro S
When recording the pressure oscillations of a seated subject two distinct effects are assessed, ample vibrations due to the person's movement, and periodic oscillations of small amplitude due to cardiopulmonary activity, expressed by the ballistocardiogram (BCG). Embedding a pressure sensor in a chair's back or seat allows unobtrusive monitoring of the BCG. However, inconspicuously acquired signals are affected by numerous artifacts, often generated by the subject's forgetfulness, and posture changes due to lack of constrains. Moreover, the signal changes considerably its shape from person to person, and when the seating posture, or conversely, sensor position, is different. For real-time continuous monitoring, it is still to be found a method which, without introducing significant delays, can deal with such volatility. Thus, tailored calibration of peak detectors and other algorithms is recurrent, and even so, the neighboring samples of artifacts are possibly untreatable. This work evaluates the advantages of Empirical Mode Decomposition, as well as a coarser demodulation approach of the BCG signal, as dependable methods to allow real-time heart rate estimation on unstable BCG records. An analysis of the Fourier transform of the demodulated signals is the method used to provide and compare robustness of heart rate estimates. PMID:21096778
Hung, Pang-Chan; Lee, Kual-Zheng; Tsai, Luo-Wei
In this paper, we propose a contact-free heart rate measurement method by analyzing sequential images of multiple video data. In the proposed method, skin-like pixels are firstly detected from multiple video data for extracting the color features. These color features are synchronized and analyzed by independent component analysis. A representative component is finally selected among these independent component candidates to measure the HR, which achieves under 2% deviation on average compared with a pulse oximeter in the controllable environment. The advantages of the proposed method include: 1) it uses low cost and high accessibility camera device; 2) it eases users' discomfort by utilizing contact-free measurement; and 3) it achieves the low error rate and the high stability by integrating multiple video data.
Cammann, Henning; Michel, Josef
Spectral analysis of R-R Interval time series is increasingly used to determine periodic components of heart rate variability (HRV). Particular diagnostic relevance is assigned to a low-frequency (LF) component, associated with blood pressure regulation, and a high-frequency (HF) component, also referred to as respiratory sinus arrhythmia (RSA) in the HRV power spectra. Frequency ranges for parametrisation of power spectra have been defined for either component in numerous publications.Results obtained from examinations with standardised psychic load in which ECG and respiratory signal are continuously recorded and adequately processed have shown that the true individual frequency range of the HF component can be reliably determined only by means of characteristics of respiration (respiratory rate (RR), range and median value of RR, tidal depth). Respiratory rhythms are interindividually extremely differentiated and of individual-specific nature. In many cases LF and HF components may be totally superimposed on each other and, consequently, cannot be diagnostically evaluated. PMID:11886699
of cardiac chaos in congestive heart failure. Nature, 389:492-495, 1997.  Poon C.-S. et al. TitrationIEEE Benelux EMBS Symposium December 6-7, 2007 HEART RATE VARIABILITY DURING ACTIVE AND QUIET SLEEP
Roberta Forte; Giuseppe De Vito; Francesco Figura
\\u000a Twenty healthy women aged between 65 and 74 years, trained three times a week, for 16 weeks, on a cycle ergometer, to determine\\u000a the effects of dynamic resistance training on heart rate variability (HRV). Subjects were allocated to two training groups,\\u000a high (HI, n=10) and low (LO, n=10) intensity. The HI group performed eight sets of 8 revolutions at 80% of the
L. Burattini; R. Burattini; C. E. Cogo; E. Faelli; P. Ruggeri
Cardiac autonomic control was studied in a group of five young hyperinsulinaemic, insulin resistant, Zucker fatty rats (ZFR) compared with a control group of five young Zucker lean rats (ZLR). Power spectrum analysis (PSA) of heart rate variability (HRV) was performed with autoregressive (AR) models. All rats were anaesthetised with sodium pentobarbital. Mean insulinaemia and glycaemia levels were 185+27 muU\\/ml
Hartmut SCHÄCHINGER; Johannes PORT; Stuart BRODY; Lilly LINDER; Daniel COX; Ulrich KELLER
Despite causing sympathetic activation, prolonged hypoglycaemia produces little change in HR (heart rate) in healthy young adults. One explanation could be concurrent parasympathetic activ- ation, resulting in unchanged net effects of autonomic influences. In the present study, hypogly- caemic (2.7 mmol\\/l) and normoglycaemic (4.7 mmol\\/l) hyperinsulinaemic clamp studies were performed after normoglycaemic baseline clamp periods with 15 healthy volunteers (seven
Ferdinando Iellamo; Jacopo M. Legramante; Gianfranco Raimondi; Filippo Castrucci; Carlo Damiani; Calogero Foti; Giuseppe Peruzzi; Ignazio Caruso
The purpose of the present study was to compare arterial pressure (AP) and heart rate (HR) responses to submaximal isokinetic,\\u000a isotonic and isometric exercises currently employed in physical rehabilitation therapy in terms of both magnitude and time-course.\\u000a To this aim AP and HR were continuously and noninvasively measured in ten healthy subjects performing isokinetic, isotonic\\u000a and isometric exercises at the
Giuseppe Piccione; Elisabetta Giudice; Francesco Fazio; Jacopo P. Mortola
We asked whether, during the postnatal period, the daily patterns of body temperature (Tb), heart rate (HR) and breathing\\u000a frequency (f) begin and develop in synchrony. To this end, measurements of HR, f and Tb were performed weekly, on two consecutive\\u000a days, for the first two postnatal months on puppies of three breeds of dogs (Rottweiler, Cocker Spaniel and Carlino
Vollono, Catello; Gnoni, Valentina; Testani, Elisa; Dittoni, Serena; Losurdo, Anna; Colicchio, Salvatore; Di Blasi, Chiara; Mazza, Salvatore; Farina, Benedetto; Della Marca, Giacomo
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
S. S. Hillman
Summary Lymphatic injection of propranolol (0.2–10 ?g) into toads decreased exercise heart rate in a dose-dependent manner. There was a significant linear corrleation between exercise heart rate and maximal oxygen consumption rates\\u000a
Gao, X. Z.; Ching, E. S. C.; Lin, D. C.
We show a hierarchical structure (HS) of the She-Leveque form in the beat-to-beat RR intervals of heart rate variability (HRV) in humans. This structure, first found as an empirical law in turbulent fluid flows, implies further details in the HRV multifractal scaling. We tested HS using daytime RRi data from healthy subjects and heart diseased patients with congestive heart failure and found a universal law C(b) where b characterizes the multifractality of HRV and C is related to a co-dimension parameter of the most violent events in the fluctuation. The potential of diagnosis is discussed based on the characteristics of this finding. To model the HRV phenomenology, we propose a local-feedback-global-cascade (LFGC) model based on the She-Waymire (SW) cascade solution to the HS in fluid turbulence. This model extends from the previous work in that it integrates additive law multiplicatively into the cascade structure. It is an attempt to relate to the cardiovascular physiology which consists of numerous feedback controls that function primarily on the principle of additive law. In particular, the model is based on the same philosophy as the SW cascade that its multifractal dynamics consists of a singular and a modulating component. In the LFGC model, we introduce local feedback to model the dynamics of the modulating effect. The novelty of our model is to incorporate the cascade structure in the scheduling for the feedback control. This model also represents an alternative solution to the HS. We will present the simulation results by the LFGC model and discuss its implication in physiology terms.
Thomas C. T. Ho; Xiang. Chen
“Musica delenit bestiam feram” translates into “Music soothes the savage beast”. There is a hidden truth in this ancient quip passed down from generations. Besides soothing the heart, it also incites the heart to a healthier level of heart rate variability (HRV). In this paper, an approach to use and test music and biofeedback to increase the heart rate variability
Buchhorn, Reiner; Conzelmann, Annette; Willaschek, Christian; Störk, Dagmar; Taurines, Regina; Renner, Tobias J
Although an extensive number of studies support the efficacy and tolerability of stimulants in the treatment of attention deficit/hyperactivity disorder (ADHD), in recent years, increasing concerns have been raised about their cardiovascular safety. We investigated whether a time domain analysis of heart rate variability (HRV) recordings in 24-h ECG under medication with stimulants yielded new information about therapy control in ADHD. We analysed the HRV parameter standard deviation of all normal sinus RR intervals over 24 h (SDNN), percentage of successive normal sinus RR intervals > 50 ms (pNN50) and root-mean-square of the successive normal sinus RR interval difference (rMSSD) from 23 children diagnosed by ADHD (19 boys and 4 girls), aged 10.5 ± 2.2 years, who were consecutively referred to our outpatient clinic for paediatric cardiology. Eleven children received medication with methylphenidate (MPH), while twelve children were initially examined without medication. Of these, eight probands were re-examined after therapy with MPH was established. Controls comprised 19 children (10 boys, 9 girls) from our Holter ECG data base without any cardiac or circulatory disease. Compared to healthy controls, the ADHD children with and without MPH treatment showed significantly higher mean heart rates (ADHD without MPH: 94.3 ± 2.2; ADHD with MPH: 90.5 ± 1.8, controls: 84.7 ± 1.8). pNN50 (ADHD without MPH: 6.5 ± 2.7; ADHD with MPH: 14.2 ± 6.9, controls: 21.5 ± 9.0) and rMSSD (ADHD without MPH: 26.1 ± 4.1; ADHD with MPH: 36.7 ± 8.3, controls: 44.5 ± 10.1) were lowest in ADHD children without MPH, middle in ADHD children with MPH and highest in controls. SDNN values were not significantly different. The hourly analysis shows highly significant reduced pNN50 and rMSSD values in untreated ADHD children between 5:00 pm and 6:00 am while the pattern approaches to levels of controls during MPH treatment. Data of this pilot study indicate a decreased vagal tone with significantly diminished HRV and higher heart rates in unmedicated ADHD children. These parameters of autonomic activation are ameliorated by MPH treatment. No evidence for negative impact of MPH on HRV was detected. Further studies will clarify a potential cardio-protective effect of MPH in ADHD. PMID:22328340
Background Experimental data suggests that exclusive heart rate reduction with ivabradine is associated with the amelioration of the endothelial function. Since it is presently unknown whether this also applies to humans, the aim of this pilot study was to investigate whether heart rate reduction with ivabradine modulates the endothelial function in humans with an established coronary heart disease. Methods Using high-sensitivity ultrasound, we analysed the flow-mediated (FMD) and nitro-mediated dilation (NMD) of the brachial artery in 25 patients (62.9?±?8.4 years) with a stable coronary heart disease and a resting heart rate of ?70 beats per minute (bpm). To assess acute effects, measurements were performed before and 4 hours after the first intake of ivabradine 7.5 mg. Sustained effects of an ivabradine therapy (5 mg to 7.5 mg twice daily) were investigated after 4 weeks. Results We found a significant decrease in heart rate, both 4 hours after the intake of 7.5 mg of ivabradine (median -8 [interquartile range (IQR) -14 to -4] bpm) and after 4 weeks of twice daily intake (median -10 [IQR-17 to -5] bpm) (p?0.05). However, the FMD did not change significantly: neither after first dose of ivabradine nor after sustained therapy (baseline FMD: median 5.0 [IQR 2.4 to 7.9]%; FMD 4 hours after 7.5 mg of ivabradine: median 4.9 [IQR 2.7 to 9.8]%; FMD after 4 weeks of ivabradine therapy: median 6.1 [IQR 4.3 to 8.2]%). No significant changes of the NMD were observed. In regression analysis, the heart rate and FMD did not correlated, irrespective of the ivabradine intake (r2?=?0.086). Conclusion In conclusion, in our study heart rate reduction through ivabradine does not improve the endothelial function in patients with a stable coronary heart disease. Moreover, we found no correlation between the heart rate and the endothelial function. PMID:24479706
Ely, C.R.; Ward, D.H.; Bollinger, K.S.
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.
David Gordon; Victoria L. Herrera; Laura McAlpine; Richard J. Cohen; Solange Akselrod; Peter Lang; William I. Norwood
Summary Children may die suddenly and unexpectedly following cardiac surgery, even while receiving intensive medical care, when current noninvasive and invasive monitoring techniques fail to warn us of an impending problem. This report examines the efficacy of heart-rate spectral analysis, a noninvasive method that quantitates the beat-to-beat fluctuations in heart rate, in characterizing and tracking cardiovascular regulatory status. A total
Abdominal Aortic Aneurysm; Coronary Heart Disease NOS; Unheralded Coronary Death; Intracerebral Haemorrhage; Heart Failure; Ischemic Stroke; Myocardial Infarction; Stroke; Peripheral Arterial Disease; Stable Angina Pectoris; Subarachnoid Haemorrhage; Transient Ischemic Attack; Unstable Angina; Cardiac Arrest, Sudden Cardiac Death
Baiget, Ernest; Fernández-Fernández, Jaime; Iglesias, Xavier; Rodríguez, Ferran A
Baiget, E, Fernández-Fernández, J, Iglesias, X, and Rodríguez, FA. Heart rate deflection point relates to second ventilatory threshold in a tennis test. J Strength Cond Res 29(3): 765-771, 2015-The relationship between heart rate deflection point (HRDP) and the second ventilatory threshold (VT2) has been studied in continuous sports, but never in a tennis-specific test. The aim of the study was to assess the relationships between HRDP and the VT2, and between the maximal test performance and the maximal oxygen uptake ((Equation is included in full-text article.)) in an on-court specific endurance tennis test. Thirty-five high-level tennis players performed a progressive tennis-specific field test to exhaustion to determine HRDP, VT2, and (Equation is included in full-text article.). Ventilatory gas exchange parameters were continuously recorded by a portable telemetric breath-by-breath gas exchange measurement system. Heart rate deflection point was identified at the point at which the slope values of the linear portion of the time/heart rate (HR) relationship began to decline and was successfully determined in 91.4% of the players. High correlations (r = 0.79-0.96; p < 0.001) between physiological (HR and oxygen uptake [(Equation is included in full-text article.)]) and performance (Time, Stage, and Frequency of balls [Ballf]) variables corresponding to HRDP and VT2 were observed. Frequency of balls at the HRDP (BallfHRDP) was detected at 19.8 ± 1.7 shots per minute. Paired t-test showed no significant differences in HR (178.9 ± 8.5 vs. 177.9 ± 8.7 b·min for HRDP vs. HRVT2, respectively) at intensities corresponding to HRDP and VT2. Maximal test performance and (Equation is included in full-text article.)were moderately correlated (r = 0.56; p < 0.001). Heart rate deflection point obtained from this specific tennis test can be used to determine the VT2, and the BallfHRDP can be used as a practical performance variable to prescribe on-court specific aerobic training at or near VT2. PMID:25162649
Sammito, S; Böckelmann, I
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
Papasimakis, N.; Pallikari, F.
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.
Kheder, G; Massoued, M Ben; Samet, M
In this paper, a new efficient feature extraction method based on the adaptive threshold of wavelet package coefficients is presented. This paper especially deals with the assessment of autonomic nervous system using the background variation of the signal Heart Rate Variability HRV extracted from the wavelet package coefficients. The application of a wavelet package transform allows us to obtain a time-frequency representation of the signal, which provides better insight in the frequency distribution of the signal with time. A 6 level decomposition of HRV was achieved with db4 as mother wavelet, and the above two bands LF and HF were combined in 12 specialized frequencies sub-bands obtained in wavelet package transform. Features extracted from these coefficients can efficiently represent the characteristics of the original signal. ANOVA statistical test is used for the evaluation of proposed algorithm.
Roh, Taehwan; Sunjoo Hong; Hoi-Jun Yoo
A wearable depression monitoring system is proposed with an application-specific system-on-chip (SoC) solution. The SoC is designed to accelerate the filtering and feature extraction of heart-rate variability (HRV) from the electrocardiogram (ECG). Thanks to the SoC solution and planar-fashionable circuit board (P-FCB), the monitoring system becomes a low-power wearable system. Its dimension is 14cm × 7cm with 5mm thickness covering the chest band for convenient usage. In addition, with 3.7V 500mAh battery, its lifetime is at least 10 hours. For user's convenience, the system is interfacing to smart phones through Bluetooth communication. With the features of the HRV and Beck depression inventory (BDI), the smart phone application trains and classifies the user's depression scale with 71% of accuracy. PMID:25570021
Chang, Mei-Chu; Peng, C.-K.; Stanley, H. Eugene
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.
Nagel, C; Erber, R; Ille, N; Wulf, M; Aurich, J; Möstl, E; Aurich, C
Heart rate (HR), HR variability (HRV) and salivary cortisol concentrations were determined in foals (n?=?13) during the perinatal phase and until 5 months of age. In the fetus, HR decreased from 77?±?3 beats/min at 120?min before birth to 60?±?1 beats/min at 5?min before birth (P?<0.01). Within 30?min of birth, HR increased to 160?±?9 beats/min (P?<0.01). Salivary cortisol concentrations immediately after birth were 11.9?±?3.6?ng/mL and within 2?h increased to a maximum of 52.5?±?12.3?ng/mL (P?<0.01). In conclusion, increases in HR and salivary cortisol concentrations in foals are not induced during parturition, but occur immediately after birth. PMID:25582796
Chou, Chia-Ying; Marca, Roberto La; Steptoe, Andrew; Brewin, Chris R
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
Otsuka, K; Izumi, R; Ishioka, N; Ohshima, H; Mukai, C
Chronomes are time structures consisting of multifrequency rhythms, elements of chaos, and trends in chaotic and rhythmic endpoints. Chronomics maps the dynamics of organisms' broad interactions with the environment near and far, rather than merely the daily routines. We introduced the chronomics of heart rate variability (HRV), characterized by a broad time structure, that includes the prominent circadians and also ultradian (notably about 8h and about 12h) and infradian (notably about-weekly, about-yearly, and about 10-yearly) changes, in addition to undergoing trends with aging. Alterations in these HRV chronomes are known to predict the presence of disease in the near future. Thus, for the health and safety of astronauts, HRV chronomes should be assessed before, during and after the mission in the International Space Station to check for any alteration. Future work should focus on how phenomena in the cosmos, including helio- and geomagnetics, can affect physiological chronomes, those of the HRV in particular. PMID:19833301
Ikonomov, O; Stoynev, G; Cornélissen, G; Stoynev, A; Hillman, D; Madjirova, N; Kane, R; Halberg, F
Rhythm characteristics of blood pressure (BP) and heart rate (Hr) of 11 healthy centenarians and 66 medical students are described. Each subject ambulatorily monitored measured BP and HR around the clock at 15-min intervals for 48 hours. Least-squares spectra were obtained by the fit of cosine curves (cosinor) and compared between the two populations. Confounding by geographic differences seems to be ruled out by comparisons with results from international data bases. A shift in prominence from the circadian domain to higher frequency harmonics was found for the BP but not for the HR of centenarians. In clinically mostly healthy centenarians, markers of primary aging may consist of a relatively low circadian BP and HR amplitude and a tendency toward internal and external desynchronization. Whether these chronobiologic changes with age are desirable, indifferent or undesirable can now be elucidated by outcome studies, in the light of the reference standards provided herein. PMID:1815852
García, Constantino A; Vila, Xosé; Márquez, David G
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...
Divon, M Y; Zimmer, E Z; Platt, L D; Paldi, E
A computerized quantification of fetal heart rate and beat-to-beat variability was performed during and between fetal breathing episodes. Sixteen healthy pregnant women at term participated in the study. The results indicate that fetal breathing is associated with a significant increase in beat-to-beat variability (from 4.48 +/- 1.66 between breathing episodes to 5.80 +/- 2.04 during breathing episodes, p less than 0.01) and a small but significant decrease in fetal heart rate (from 142.7 +/- 8.6 bpm between breathing episodes to 140.4 +/- 8.6 bpm during breathing episodes, p less than 0.05). PMID:3970108
Fontana, A; McLaughlin, M
An anger-provocation paradigm was used to assess the effects of coping processes and appraisal of daily stressors on stress reactivity in 33 normotensive undergraduate women. Participants performed a mental arithmetic and an interpersonal conflict task during the pre- and postmenstrual phases of their menstrual cycles. Increased use of the emotion-focused coping processes of tension reduction and positive reappraisal was correlated with lower levels of baseline heart rate, whereas distancing was associated with higher levels of systolic blood pressure reactivity during the conflict task. Perceiving daily stressors as more stressful was associated with higher baseline diastolic blood pressure levels. The authors concluded that the transactional model of stress is useful for generating hypotheses about factors that predict heart rate and blood pressure levels in women. PMID:9575387
Carney, Robert M.; Freedland, Kenneth E.; Stein, Phyllis K.; Miller, Gregory E.; Steinmeyer, Brian; Rich, Michael W.; Duntley, Stephen P.
Background Depression is associated with an increased risk for cardiac morbidity and mortality in patients with coronary heart disease(CHD). Cardiac autonomic nervous system (ANS) dysregulation, proinflammatory processes, and procoagulant processes, have been suggested as possible explanations. Methods Heart rate variability (HRV), an indicator of cardiac autonomic regulation, and markers of inflammation [C-reactive protein (CRP), interleukin-6 (IL-6), tumor necrosis factor (TNF?)] and coagulation (fibrinogen) were assessed in 44 depressed patients with CHD. Results Moderate, negative correlations were found between fibrinogen and four measures of HRV. Il-6 also negatively correlated with one measure of HRV (total power), and was marginally related to two others (very low frequency and low frequency power). Neither CRP nor TNF-? were significantly related to any measure of HRV. Conclusions The finding that fibrinogen and Il-6 are moderately related to HRV suggests a link between these factors in depressed CHD patients. The relationship between autonomic nervous system function and inflammatory and coagulant processes should be investigated in larger mechanistic studies of depression and cardiac morbidity and mortality. PMID:17383498
Stalder, Tobias; Evans, Phil; Hucklebridge, Frank; Clow, Angela
The process of morning awakening is associated with a marked increase in cortisol secretion, the cortisol awakening response (CAR), as well as with a burst in cardiovascular (CV) activation. Whilst the CAR is largely driven by awakening-induced activation of hypothalamic-pituitary-adrenal axis, it is fine-tuned by direct sympathetic input to the adrenal gland. In parallel, awakening-induced activation of the CV system is associated with a shift towards dominance of the sympathetic branch of the autonomic nervous system. Moreover, the CAR, in common with trait-like heart rate variability (HRV), is widely reported to be associated with psychosocial variables and health outcomes. These commonalities led us to examine associations between the CAR and both concurrent awakening-induced changes and trait-like estimates in cardiovascular activity (heart rate (HR) and HRV). Self-report measures of difficulties in emotion regulation and chronic stress were also obtained. Forty-three healthy participants (mean age: 23 years) were examined on two consecutive weekdays. On both days, heart interbeat interval (IBI) data was obtained from sedentary laboratory recordings as well as from recordings over the peri-awakening period. Salivary free cortisol concentrations were determined on awakening and 15, 30, and 45min post-awakening on both study days. Data from a minimum of 36 participants were available for individual analyses. Results revealed significant awakening-induced changes in cortisol, HR and HRV measures; however, no associations were found between the simultaneous post-awakening changes of these variables. Similarly, awakening-induced changes in cortisol, HR and HRV measures were not significantly associated with perceived stress or measures of emotion regulation. However, the CAR was found to be significantly positively correlated with steady state measures of HR and negatively correlated with steady state measures of HRV, as determined during the laboratory sessions and the peri-awakening periods. This cross-sectional study indicates that, despite consistent associations between the CAR and indices of trait-like cardiovascular activity, the CAR is not related to concurrent changes of cardiac autonomic activation following awakening. PMID:20732747
Crone, Eveline A.; Somsen, Riek J. M.; Zanolie, Kiki; Van der Molen, Maurits W.
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,…
Henry, Brook L.; Minassian, Arpi; Paulus, Martin P.; Geyer, Mark A.; Perry, William
Background Autonomic nervous system (ANS) dysfunction and reduced heart rate variability (HRV) have been reported in a wide variety of psychiatric disorders, but have not been well characterized in bipolar mania. We recorded cardiac activity and assessed HRV in acutely hospitalized manic bipolar (BD) and schizophrenia (SCZ) patients compared to age- and gender-matched healthy comparison (HC) subjects. Method HRV was assessed using time domain, frequency domain, and nonlinear analyses in 23 manic BD, 14 SCZ, and 23 HC subjects during a 5 minute rest period. Psychiatric symptoms were assessed by administration of the Brief Psychiatric Rating Scale (BPRS) and the Young Mania Rating Scale (YMRS). Results Manic BD patients demonstrated a significant reduction in HRV, parasympathetic activity, and cardiac entropy compared to HC subjects, while SCZ patients demonstrated a similar, but non-significant, trend towards lower HRV and entropy. Reduction in parasympathetic tone was significantly correlated with higher YMRS scores and the unusual thought content subscale on the BPRS. Decreased entropy was associated with increased aggression and diminished personal hygiene on the YMRS scale. Conclusion Cardiac function in manic BD individuals is characterized by decreased HRV, PMID:19700172
Sung, Yun Ju; Sarzynski, Mark A.; Rice, Treva K.; Rao, D. C.; Bouchard, Claude
Endurance training-induced changes in hemodynamic traits are heritable. However, few genes associated with heart rate training responses have been identified. The purpose of our study was to perform a genome-wide association study to uncover DNA sequence variants associated with submaximal exercise heart rate training responses in the HERITAGE Family Study. Heart rate was measured during steady-state exercise at 50 W (HR50) on 2 separate days before and after a 20-wk endurance training program in 483 white subjects from 99 families. Illumina HumanCNV370-Quad v3.0 BeadChips were genotyped using the Illumina BeadStation 500GX platform. After quality control procedures, 320,000 single-nucleotide polymorphisms (SNPs) were available for the genome-wide association study analyses, which were performed using the MERLIN software package (single-SNP analyses and conditional heritability tests) and standard regression models (multivariate analyses). The strongest associations for HR50 training response adjusted for age, sex, body mass index, and baseline HR50 were detected with SNPs at the YWHAQ locus on chromosome 2p25 (P = 8.1 × 10?7), the RBPMS locus on chromosome 8p12 (P = 3.8 × 10?6), and the CREB1 locus on chromosome 2q34 (P = 1.6 × 10?5). In addition, 37 other SNPs showed P values <9.9 × 10?5. After removal of redundant SNPs, the 10 most significant SNPs explained 35.9% of the ?HR50 variance in a multivariate regression model. Conditional heritability tests showed that nine of these SNPs (all intragenic) accounted for 100% of the ?HR50 heritability. Our results indicate that SNPs in nine genes related to cardiomyocyte and neuronal functions, as well as cardiac memory formation, fully account for the heritability of the submaximal heart rate training response. PMID:22174390
dynamics in HRV of healthy, congestive heart failure (CHF), and atrial fibrillation subjects. We show, congestive heart failure (CHF), and atrial fibrillation (AF). We shall further compare SDLE with otherMultiscale Analysis of Heart Rate Variability: A Comparison of Different Complexity Measures JING
Lynne I. Mason; Robert P. Patterson
Voluntary cardio-respiratory synchronization (VCRS) was used to investigate heart rate and blood pressure changes in the supine position in 21 subjects. VCRS involves a breathing pattern that is synchronized with the cardiac cycle. The signals to inhale and exhale are derived from the ECG. In this study, the subjects inspired for four heart beats and expired for four heart beats
Rebeca Goya-Esteban; Inmaculada Mora-Jiménez; José Luis Rojo-Álvarez; Óscar Barquero-Pérez; Francisco J. Pastor-Pérez; Sergio Manzano-Fernández; Domingo A. Pascual-Figal; Arcadi García-Alberola
Heart rate variability (HRV) markers have been widely used to characterize the autonomous regulation state of the heart from 24-h Holter monitoring, but long-term evolution of HRV indexes is mostly unknown. A dataset of 7-day Holter recordings of 22 patients with congestive heart failure was studied. A rhythmometric procedure was designed to characterize the infradian, circadian, and ultradian components for
Robert J. Storella; Harrison W. Wood; Kenneth M. Mills; Jřrgen K. Kanters; Michael V. Hřjgaard; Niels-Henrik Holstein-Rathlou
The contribution of nonlinear dynamics to heart rate variability in healthy humans was examined using surrogate data analysis.\\u000a Several measures of heart rate variability were used and compared. Heart rates were recorded for three hours and original\\u000a data sets of 8192 R-R intervals created. For each original data set (n=34), three surrogate data sets were made by shuffling\\u000a the order
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
Chamberlain, Alanna M.; Manemann, Sheila M.; Dunlay, Shannon M.; Spertus, John A.; Moser, Debra K.; Berardi, Cecilia; Kane, Robert L.; Weston, Susan A.; Redfield, Margaret M.; Roger, Véronique L.
Background Heart failure (HF) patients experience impaired functional status, diminished quality of life, high utilization of healthcare resources, and poor survival. Yet, the identification of patient?centered factors that influence prognosis is lacking. Methods and Results We determined the association of 2 measures of self?rated health with healthcare utilization and skilled nursing facility (SNF) admission in a community cohort of 417 HF patients prospectively enrolled between October 2007 and December 2010 from Olmsted County, MN. Patients completed a 12?item Short Form Health Survey (SF?12). Low self?reported physical functioning was defined as a score ?25 on the SF?12 physical component. The first question of the SF?12 was used as a measure of self?rated general health. After 2 years, 1033 hospitalizations, 1407 emergency department (ED) visits, and 19,780 outpatient office visits were observed; 87 patients were admitted to a SNF. After adjustment for confounding factors, an increased risk of hospitalizations (1.52 [1.17 to 1.99]) and ED visits (1.48 [1.04 to 2.11]) was observed for those with low versus moderate?high self?reported physical functioning. Patients with poor and fair self?rated general health also experienced an increased risk of hospitalizations (poor: 1.73 [1.29 to 2.32]; fair: 1.46 [1.14 to 1.87]) and ED visits (poor: 1.73 [1.16 to 2.56]; fair: 1.48 [1.13 to 1.93]) compared with good?excellent self?rated general health. No association between self?reported physical functioning or self?rated general health with outpatient visits and SNF admission was observed. Conclusion In community HF patients, self?reported measures of physical functioning predict hospitalizations and ED visits, indicating that these patient?reported measures may be useful in risk stratification and management in HF. PMID:24870937
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
P. E. McSharry; M. J. McGuinness; A. C. Fowler
The cardiovascular system may be investigated by observing fluctuations in the heart rate, blood pressure and rate of respiration. Its time evolution is governed by the baroreflex control mechanism, where the sympathetic and vagal nerves compete to increase and decrease the heart rate respectively. A nonlinear delay-differential equation model is constructed to describe this control mechanism and to explore the
K F Koltyn; W P Morgan
The purpose of this investigation was to compare the effectiveness of using ratings of perceived exertion (RPE) with heart rate in the monitoring of exercise intensity during aerobic dance instruction. Thirty-eight students who enrolled in aerobic dance classes used heart rate to monitor exercise intensity while 38 additional students used RPE to monitor exercise intensity during a 14-week course. Classes
Anselmino, Matteo; Camporeale, Carlo; Saglietto, Andrea; Gaita, Fiorenzo; Ridolfi, Luca
Background. Despite the routine prescription of rate control therapy for atrial fibrillation (AF), clinical evidence demonstrating a heart rate target is lacking. Aim of the present study was to run a mathematical model simulating AF episodes with a different heart rate (HR) to predict hemodynamic parameters for each situation. Methods. The lumped model, representing the pumping heart together with systemic and pulmonary circuits, was run to simulate AF with HR of 50, 70, 90, 110 and 130 bpm, respectively. Results. Left ventricular pressure increased by 56.7%, from 33.92+-37.56 mmHg to 53.15+-47.56 mmHg, and mean systemic arterial pressure increased by 27.4%, from 82.66+-14.04 mmHg to 105.29+-7.63 mmHg, at the 50 and 130 bpm simulations, respectively. Stroke volume (from 77.45+-8.5 to 39.09+-8.08 mL), ejection fraction (from 61.1+-4.4 to 39.32+-5.42%) and stroke work (SW, from 0.88+-0.04 to 0.58+-0.09 J) decreased by 49.5, 35.6 and 34.2%, at the 50 and 130 bpm simulations, respectively. In addition, oxygen co...
Rauh, Robert; Limley, Robert; Bauer, Rainer-Dieter; Radespiel-Troger, Martin; Mueck-Weymann, Michael
This study compares ear photoplethysmography (PPG) and electrocardiogram (ECG) in providing accurate heart beat intervals for use in calculations of heart rate variability (HRV, from ECG) or of pulse rate variability (PRV, from PPG) respectively. Simultaneous measurements were taken from 44 healthy subjects at rest during spontaneous breathing and during forced metronomic breathing (6/min). Under both conditions, highly significant (p > 0.001) correlations (1.0 > r > 0.97) were found between all evaluated common HRV and PRV parameters. However, under both conditions the PRV parameters were higher than HRV. In addition, we calculated the limits of agreement according to Bland and Altman between both techniques and found good agreement (< 10% difference) for heart rate and standard deviation of normal-to-normal intervals (SDNN), but only moderate (10-20%) or even insufficient (> 20%) agreement for other standard HRV and PRV parameters. Thus, PRV data seem to be acceptable for screening purposes but, at least at this state of knowledge, not for medical decision making. However, further studies are needed before more certain determination can be made.
... Section 430.308 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PERFORMANCE MANAGEMENT Managing Senior Executive Performance § 430.308 Rating performance. (a) Initial summary...
Yeh, Huei-Ming; Chang, Yi-Chung; Lin, Chen; Yeh, Chien-Hung; Lee, Chien-Nan; Shyu, Ming-Kwang; Hung, Ming-Hui; Hsiao, Po-Ni; Wang, Yung-Hung; Tseng, Yu-Hsin; Tsao, Jenho; Lai, Ling-Ping; Lin, Lian-Yu; Lo, Men-Tzung
Background Monitoring of fetal heart rate (FHR) is important during labor since it is a sensitive marker to obtain significant information about fetal condition. To take immediate response during cesarean section (CS), we noninvasively derive FHR from maternal abdominal ECG. Methods We recruited 17 pregnant women delivered by elective cesarean section, with abdominal ECG obtained before and during the entire CS. First, a QRS-template is created by averaging all the maternal ECG heart beats. Then, Hilbert transform was applied to QRS-template to generate the other basis which is orthogonal to the QRS-template. Second, maternal QRS, P and T waves were adaptively subtracted from the composited ECG. Third, Gabor transformation was applied to obtain time-frequency spectrogram of FHR. Heart rate variability (HRV) parameters including standard deviation of normal-to-normal intervals (SDNN), 0V, 1V, 2V derived from symbolic dynamics of HRV and SD1, SD2 derived from Poincareé plot. Three emphasized stages includes: (1) before anesthesia, (2) 5 minutes after anesthesia and (3) 5 minutes before CS delivery. Results FHRs were successfully derived from all maternal abdominal ECGs. FHR increased 5 minutes after anesthesia and 5 minutes before delivery. As for HRV parameters, SDNN increased both 5 minutes after anesthesia and 5 minutes before delivery (21.30±9.05 vs. 13.01±6.89, P < 0.001 and 22.88±12.01 vs. 13.01±6.89, P < 0.05). SD1 did not change during anesthesia, while SD2 increased significantly 5 minutes after anesthesia (27.92±12.28 vs. 16.18±10.01, P < 0.001) and both SD2 and 0V percentage increased significantly 5 minutes before delivery (30.54±15.88 vs. 16.18±10.01, P < 0.05; 0.39±0.14 vs. 0.30±0.13, P < 0.05). Conclusions We developed a novel method to automatically derive FHR from maternal abdominal ECGs and proved that it is feasible during CS. PMID:25680192
Raab, Corinna; Wessel, Niels; Schirdewan, Alexander; Kurths, Jürgen
In this work, we reanalyze the heart rate variability (HRV) data from the 2002 Computers in Cardiology (CiC) Challenge using the concept of large-scale dimension densities and additionally apply this technique to data of healthy persons and of patients with cardiac diseases. The large-scale dimension density (LASDID) is estimated from the time series using a normalized Grassberger-Procaccia algorithm, which leads to a suitable correction of systematic errors produced by boundary effects in the rather large scales of a system. This way, it is possible to analyze rather short, nonstationary, and unfiltered data, such as HRV. Moreover, this method allows us to analyze short parts of the data and to look for differences between day and night. The circadian changes in the dimension density enable us to distinguish almost completely between real data and computer-generated data from the CiC 2002 challenge using only one parameter. In the second part we analyzed the data of 15 patients with atrial fibrillation (AF), 15 patients with congestive heart failure (CHF), 15 elderly healthy subjects (EH), as well as 18 young and healthy persons (YH). With our method we are able to separate completely the AF (?ls?=0.97±0.02) group from the others and, especially during daytime, the CHF patients show significant differences from the young and elderly healthy volunteers (CHF, 0.65±0.13 ; EH, 0.54±0.05 ; YH, 0.57±0.05 ; p<0.05 for both comparisons). Moreover, for the CHF patients we find no circadian changes in ?ls? (day, 0.65±0.13 ; night, 0.66±0.12 ; n.s.) in contrast to healthy controls (day, 0.54±0.05 ; night, 0.61±0.05 ; p=0.002 ). Correlation analysis showed no statistical significant relation between standard HRV and circadian LASDID, demonstrating a possibly independent application of our method for clinical risk stratification.
Pratt, Wanda M.; Siconolfi, Steven F.; Webster, Laurie; Hayes, Judith C.; Mazzocca, Augustus D.; Harris, Bernard A., Jr.
Two methods are compared for observing the heart rate (HR), metabolic equivalents, and time in target HR zone (defined as the target HR + or - 5 bpm) during 20 min of exercise at a prescribed intensity of the maximum working capacity. In one method, called set-work rate exercise, the information from a graded exercise test is used to select a target HR and to calculate a corresponding constant work rate that should induce the desired HR. In the other method, the work rate is controlled by a computer algorithm to achieve and maintain a prescribed target HR. It is shown that computer-controlled exercise is an effective alternative to the traditional set work rate exercise, particularly when tight control of cardiovascular responses is necessary.
Bazanova, O M; Balioz, N V; Muravleva, K B; Skoraia, M V
In order to study the effect of the alpha EEG power increasing training at heart rate variability (HRV) as the index of the autonomic regulation of cognitive functions there were follow tasks: (1) to figure out the impact of biofeedback in the voluntary increasing the power in the individual high-frequency alpha-band effect on heart rate variability and related characteristics of cognitive and emotional spheres, (2) to determine the nature of the relationship between alpha activity indices and heart rate variability, depending on the alpha-frequency EEG pattern at rest (3) to examine how the individual alpha frequency EEG pattern is reflected in changes HRV as a result of biofeedback training. Psychometric indicators of cognitive performance, the characteristics of the alpha-EEG activity and heart rate variability (HRV) as LF/HF and pNN50 were recorded in 27 healthy men aged 18-34 years, before, during, and after 10 sessions of training of voluntary increase in alpha power in the individual high-frequency alpha band with eyes closed. To determine the biofeedback effect on the alpha power increasing training, data subjects are compared in 2 groups: experimental (14) with the real and the control group (13 people)--with mock biofeedback. The follow up effect of trainings was studied through month over the 10 training sessions. Results showed that alpha biofeedback training enhanced the fluency and accuracy in cognitive performance, decreased anxiety and frontal EMG, increased resting frequency, width and power in individual upper alpha range only in participants with low baseline alpha frequency. While mock biofeedback increased resting alpha power only in participants with high baseline resting alpha frequency and did change neither cognitive performance, nor HRV indices. Biofeedback training eliminated the alpha power decrease in response to arithmetic task in both with high and low alpha frequency participants and this effect was followed up over the month. Mock biofeedback training has no such effect. The positive correlation between the alpha-peak frequency and pNN50 in patients with initially low, but negative--those with high baseline alpha frequency explains the multidirectional biofeedback effects on HRV in low and high alpha frequency subjects. The individual alpha-frequency EEG pattern determines the effectiveness of the alpha EEG biofeedback training in changing heart rate variability, which provides a basis for predicting the results and develop individual approaches to the biofeedback technology implementation that can be used in clinical practice for treatment and rehabilitation of psychosomatic syndromes and in educational training. PMID:23668077
Sakakibara, Masahito; Hayano, Junichiro; Oikawa, Leo O; Katsamanis, Maria; Lehrer, Paul
The present study was designed to examine the effect of heart rate variability (HRV) biofeedback on the cardiorespiratory resting function during sleep in daily life. Forty-five healthy young adults were randomly assigned to one of three groups: HRV biofeedback, Autogenic Training(AT), and no-treatment control. Participants in the HRV biofeedback were instructed to use a handheld HRV biofeedback device before their habitual bedtime, those in the AT were asked to listen to an audiotaped instruction before bedtime,and those in the control were asked to engage in their habitual activity before bedtime. Pulse wave signal during sleep at their own residences was measured continuously with a wrist watch-type transdermal photoelectric sensor for three time points. Baseline data were collected on the first night of measurements, followed by two successive nights for HRV biofeedback, AT, or control. Cardiorespiratory resting function was assessed quantitatively as the amplitude of high frequency(HF) component of pulse rate variability, a surrogate measure of respiratory sinus arrhythmia. HF component increased during sleep in the HRV biofeedback group,although it remained unchanged in the AT and control groups. These results suggest that HRV biofeedback before sleep may improve cardiorespiratory resting function during sleep. PMID:23959190
Kornet, L; Jansen, J R; Nijenhuis, F C; Langewouters, G J; Versprille, A
1. The influence of mean pulmonary arterial pressure (mean Ppa) on dynamic (Cd) and pseudo-static compliance (Cps) of the pulmonary artery was studied at a constant and a changing heart rate. Cd is the change in cross-sectional area (CSA) relative to the change in Ppa throughout a heart cycle. Cps is the change in mean CSA relative to the change in mean Ppa. If Cd is known, pulmonary blood flow can be computed from the Ppa using a windkessel model. We investigated whether Cps can be interchanged with Cd. 2. In nine anaesthetized pigs, we determined the mean CSA and Cd of the pulmonary artery at various Ppa levels, ranging from approximately 30 to 10 mmHg, established by bleeding. Two series of measurements were carried out, one series at a spontaneously changing heart rate (n = 9) and one series at a constant heart rate (n = 6). To determine CSA a conductance method was used. 3. Cps depended on pressure. The mean CSA versus mean Ppa curves were sigmoid and steepest in the series with the increasing heart rate (established by bleeding). The CSA versus Ppa loop during a heart cycle, giving Cd, was approximately linear and almost closed. The Cd versus mean Ppa relationship was bell shaped. Its width was smaller if the heart rate increased during the series of measurements. The pressure, where Cd was maximum, was higher at higher heart rates. Furthermore, the maximum Cd was not affected by the heart rate. 4. Because the pulmonary artery constricts with increasing heart rate, Cps will be overestimated during procedures where heart rate increases. Cd should be determined on a beat-to-beat basis to calculate flow because it changes with mean pulmonary arterial pressure and heart rate. PMID:9769432
Kornet, L; Jansen, J R C; te Nijenhuis, F C A M; Langewouters, G J; Versprille, A
The influence of mean pulmonary arterial pressure (mean Ppa) on dynamic (Cd) and pseudo-static compliance (Cps) of the pulmonary artery was studied at a constant and a changing heart rate. Cd is the change in cross-sectional area (CSA) relative to the change in Ppa throughout a heart cycle. Cps is the change in mean CSA relative to the change in mean Ppa. If Cd is known, pulmonary blood flow can be computed from the Ppa using a windkessel model. We investigated whether Cps can be interchanged with Cd. In nine anaesthetized pigs, we determined the mean CSA and Cd of the pulmonary artery at various Ppa levels, ranging from approximately 30 to 10 mmHg, established by bleeding. Two series of measurements were carried out, one series at a spontaneously changing heart rate (n = 9) and one series at a constant heart rate (n = 6). To determine CSA a conductance method was used. Cps depended on pressure. The mean CSA versus mean Ppa curves were sigmoid and steepest in the series with the increasing heart rate (established by bleeding). The CSA versus Ppa loop during a heart cycle, giving Cd, was approximately linear and almost closed. The Cdversus mean Ppa relationship was bell shaped. Its width was smaller if the heart rate increased during the series of measurements. The pressure, where Cd was maximum, was higher at higher heart rates. Furthermore, the maximum Cd was not affected by the heart rate. Because the pulmonary artery constricts with increasing heart rate, Cps will be overestimated during procedures where heart rate increases. Cd should be determined on a beat-to-beat basis to calculate flow because it changes with mean pulmonary arterial pressure and heart rate. PMID:9769432
Rummel, J. A.
As part of the operational biomedical monitoring for Apollo manned missions, ECG and respiration rate are telemetered at selected intervals to mission control. The data were collected as part of this monitoring program. These data were evaluated for circadian and ultradian rhythmicity because of their uniqueness. The ability to detect and quantitate biorhythms in living systems during space flight is an important aspect of evaluating hypotheses concerning the underlying mechanisms of these phenomena. Circadian variation in heart rate during space flight is demonstrated here. In analyzing generated time series data it has been found that period discrimination is much better than the theoretical limit.
Smith, Alan D.; Rupp, William T.
One major purpose of performance appraisals is to determine individual merit, especially where pay for performance systems are employed. Based upon expectancy theory, high performance ratings should entail high merit increases while low performance ratings result in low merit increases. However, it appears that decoupling performance ratings and…
Zenchenko, Tatjana; Jordanova, Malina; Poskotinova, Lilia; Medvedeva, Anna; Uzunov, Todor; Alenikova, Alexandra; Breus, Tamara
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.
Billat, Véronique L.; Mille-Hamard, Laurence; Meyer, Yves; Wesfreid, Eva
The aim of this study was to detect changes in the fractal scaling behavior of heart rate and speed fluctuations when the average runner’s speed decreased with fatigue. Scaling analysis in heart rate (HR) and speed (S) dynamics of marathon runners was performed using the detrended fluctuation analysis (DFA) and the wavelet based structure function. We considered both: the short-range ( ?1) and the long-range ( ?2) scaling exponents for the DFA method separated by a change-point, n0=64=5.3 min (box length), the same for all the races. The variability of HR and S decreased in the second part of the marathon race, while the cardiac cost time series (i.e. the number of cardiac beats per meter) increased due to the decreasing speed behavior. The scaling exponents ?1 and ?2 of HR and ?1 of S, increased during the race ( p<0.01) as did the HR wavelet scaling exponent ( ?). These findings provide evidence of the significant effect of fatigue induced by long exercise on the heart rate and speed variability.
Aletti, Federico; Ferrario, Manuela; de Jesus, Taiana Bertacini Almas; Stirbulov, Roberto; Silva, Audrey Borghi; Cerutti, Sergio; Sampaio, Luciana Malosa
Congenital heart defects affect the efficiency and functionality of the heart, and autonomic control of heart rate and of circulation can display a pathologic behavior in order to compensate for the hemodynamic alterations due to disease. While previous works have investigated heart rate variability (HRV) in specific pathologies, e.g. tetralogy of Fallot, the goal of this study was to assess HRV in children with a congenital heart malformation taking into account the effects of cyanotic and acyanotic defects, and comparing pathologic children with age matched controls. HRV, approximate entropy (ApEn) and sample entropy (SampEn) were calculated to discuss the dynamics and complexity of heart rhythms, and to evaluate the potential impairment of control mechanisms. Analyses showed that low frequency (LF) power and total power of HRV were significantly higher in children with a condition than in healthy controls, independently of cyanosis. Non linear indices were also significantly higher in pathologic subjects. Significant differences in LF, total power, ApEn and SampEn were found among cyanotic, acyanotic and healthy children. These results suggested that children with a congenital heart condition display more complex HRV and sympathetic overactivity, which may be aimed at compensating for hemodynamic alterations. Further studies should investigate whether corrective surgery and rehabilitation can improve HRV and restore its physiological features. PMID:23366851
Bartels-Ferreira, Rhenan; de Sousa, Élder D; Trevizani, Gabriela A; Silva, Lilian P; Nakamura, Fábio Y; Forjaz, Cláudia L M; Lima, Jorge Roberto P; Peçanha, Tiago
The time-constant of postexercise heart rate recovery (HRR? ) obtained by fitting heart rate decay curve by a first-order exponential fitting has being used to assess cardiac autonomic recovery after endurance exercise. The feasibility of this model was not tested after resistance exercise (RE). The aim of this study was to test the goodness of fit of the first-order exponential decay model to fit heart rate recovery (HRR) after RE. Ten healthy subjects participated in the study. The experimental sessions occurred in two separated days and consisted of performance of 1 set of 10 repetitions at 50% or 80% of the load achieved on the one-repetition maximum test [low-intensity (LI) and high-intensity (HI) sessions, respectively]. Heart rate (HR) was continuously registered before and during exercise and also for 10 min of recovery. A monoexponential equation was used to fit the HRR curve during the postexercise period using different time windows (i.e. 30, 60, 90, … 600 s). For each time window, (i) HRR? was calculated and (ii) variation of HR explained by the model (R(2) goodness of fit index) was assessed. The HRR? showed stabilization from 360 and 420 s on LI and HI, respectively. Acceptable R(2) values were observed from the 360 s on LI (R(2) > 0·65) and at all tested time windows on HI (R(2) > 0·75). In conclusion, this study showed that using a minimum length of monitoring (~420 s) HRR after RE can be adequately modelled by a first-order exponential fitting. PMID:24494748
Ribeiro, Jerri Luiz; de Castro, Bruno Ogoday S. D.; Rosa, Caio S.; Baptista, Rafael R.; Oliveira, Alvaro R.
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 Points Heart 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
Jordanova, Malina; Zenchenko, Tatiana; Poskotinova, Lilia; Medvedeva, Anna; Uzunov, Todor; Alenikova, Alexandra
Space Climate is an interdisciplinary science that deals with the long-term change in the Sun, and its effects in the near-Earth environment, including possible effects on human health. This paper will present the first results from simultaneous experiments performed at 3 different locations - Sofia, Bulgaria 42° 40' N 23° 20' E; Moscow, Russia 55° 45' N 37° 36‘ E and Arkhangelsk, Russia 64° 34' N / 40° 32' E. Subjects are 5 healthy volunteers, women, mean age 39,4 years. The experiments are part of the project “Heliobiology” (2011 - 2015) that reflects the intense interest towards the influence of solar activity and meteorology on the human health. The aim of the experiments is to study the degree of conjugation of the heart rate variability and the variations of the geomagnetic field. To minimize the experimental bias one and the same hard- and software were applied during the testing. ECG signals were 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 120 minutes. A comparison of the dynamics of the minute variations of the heart rate with the horizontal components of the geomagnetic field vector revealed a synchronization of some of the research parameters as well as specific individual differences. Despite of the small sample size (5 subjects per 8 measures), in over 70% of the experimental data a similar patterns of variation of geophysical and heart rate variability were recorded. The experiments discussed involved healthy volunteers, i.e. people that have good adaptation reserves, and the response to variation of geomagnetic field will not push them beyond the physiological norms. The observed effect of synchronization of heart rate fluctuations of healthy subjects with fluctuations of geomagnetic field may give an effective tool to address further one especially interesting problems - the mechanism of geomagnetic sensitivity.
Angela Ibald-Mulli; Kirsi L. Timonen; Annette Peters; Joachim Heinrich; Gabriele Wölke; Timo Lanki; Gintautas Buzorius; Wolfgang G. Kreyling; Jeroen de Hartog; Gerard Hoek; Harry M. ten Brink; Juha Pekkanen
Given the hypothesis that air pollution is associated with elevated blood pressure and heart rate, the effect of daily concentrations of air pollution on blood pressure and heart rate was assessed in 131 adults with coronary heart disease in Helsinki, Finland; Erfurt, Germany; and Amsterdam, the Netherlands. Blood pressure was measured by a digital monitor, and heart rate was calculated
Nascimento, Bruno Ramos; Lima, Márcia Maria Oliveira; Nunes, Maria do Carmo Pereira; de Alencar, Maria Clara Noman; Costa, Henrique Silveira; Pinto Filho, Marcelo Martins; Cota, Vitor Emanuel Serafim; Rocha, Manoel Otávio da Costa; Ribeiro, Antonio Luiz Pinho
Background: Heart rate variability (HRV) is a marker of autonomic dysfunction severity. The effects of physical training on HRV indexes in Chagas heart disease (CHD) are not well established. Objective: To evaluate the changes in HRV indexes in response to physical training in CHD. Methods: Patients with CHD and left ventricular (LV) dysfunction, physically inactive, were randomized either to the intervention (IG, N = 18) or control group (CG, N = 19). The IG participated in a 12-week exercise program consisting of 3 sessions/week. Results: Mean age was 49.5 ± 8 years, 59% males, mean LVEF was 36.3 ± 7.8%. Baseline HRV indexes were similar between groups. From baseline to follow-up, total power (TP): 1653 (IQ 625 - 3418) to 2794 (1617 - 4452) ms, p = 0.02) and very low frequency power: 586 (290 - 1565) to 815 (610 - 1425) ms, p = 0.047) increased in the IG, but not in the CG. The delta (post - pre) HRV indexes were similar: SDNN 11.5 ± 30.0 vs. 3.7 ± 25.1 ms. p = 0.10; rMSSD 2 (6 - 17) vs. 1 (21 - 9) ms. p = 0.43; TP 943 (731 - 3130) vs. 1780 (921 - 2743) Hz. p = 0.46; low frequency power (LFP) 1.0 (150 - 197) vs. 60 (111 - 146) Hz. p = 0.85; except for high frequency power, which tended to increase in the IG: 42 (133 - 92) vs. 79 (61 - 328) Hz. p = 0.08). Conclusion: In the studied population, the variation of HRV indexes was similar between the active and inactive groups. Clinical improvement with physical activity seems to be independent from autonomic dysfunction markers in CHD. PMID:25098373
. These condi3ons include: heart disease, high blood pressure, autoimmune disorders, diabetes as high-risk include: heart disease, high blood pressure, autoimmune disordersBaby Beats: Mobile Device and Applica5on for Measuring Fetal Heart Rate
H. Tazawa; G. Causey Whittow
Developmental patterns of embryonic heart rate were measured non-invasively in two procellariiform seabirds, the Laysan albatross (Diomedea immutabilis) and wedge-tailed shearwater (Puffinus pacificus), during prepipping and after pipping. The O2 pulse, defined as the O2 consumption per single heart beat, was calculated using the previously reported O2 consumption for these species. The embryonic heart rate of the albatross was not
Goya Wannamethee; A. Gerald Shaper
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
Yutaka Yoshida; Kiyoko Yokoyama; Akihiko Uehara; Chinori Kurata; Kazuyuki Takata
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
Micha Tobias Maeder; Peter Ammann; Hans Rickli; Hans Peter Brunner-La Rocca
Heart rate recovery 1 min after exercise termination (HRR-1) is a prognostic predictor. However, the influence of the exercise\\u000a mode on HRR-1 is incompletely characterised. Twenty-nine young and healthy subjects and 16 elderly patients with chronic heart\\u000a failure underwent cardiopulmonary exercise testing using cycle ergometer and treadmill ramp protocols in random order. HRR-1\\u000a and heart rate recovery 2 and 3
Signore, P E; Jones, D R
Neural control of the cardiac responses to exercise in air (running) and under water (diving) was studied in the muskrat (Ondatra zibethicus) by means of acute pharmacological blockade with the muscarinic blocker atropine and the beta-adrenergic blocker nadolol. Saline injection was used as a control. Controls running on a treadmill showed a marked increase in heart rate with exercise. Atropine-treated animals had a higher resting heart rate than controls, but heart rate still increased with running. Nadolol-treated animals had a lower resting heart rate than controls and displayed a less pronounced increase in heart rate with running than controls. Animals treated with a combination of atropine and nadolol had a resting heart rate similar to that of controls but their heart rate was unaffected by running. Thus, exercise tachycardia in muskrats is due to activation of the sympathetic system and also to a reduction in parasympathetic tone. Heart rate decreased markedly during voluntary submergence in controls but rose as muskrats swam submerged against increasing water flows. Nevertheless, diving bradycardia was still present. Free-diving bradycardia and the relative increase in heart rate with underwater exercise were abolished by atropine and unaffected by nadolol. Hence, unlike the cardiac response to exercise in air, the cardiac response to underwater exercise is due only to a reduction in parasympathetic tone. Injection of the beta-adrenergic agonist isoproterenol markedly increased heart rate in air but had little effect during voluntary and forced dives, indicating a marked decrease in the sensitivity of cardiac cells to adrenergic stimulation during submergence. These results strongly suggest that accentuated antagonism between the two branches of the autonomic nervous system occurs during diving so that parasympathetic influences on the heart predominate and inhibit any chronotropic response to adrenergic stimulation. PMID:8699158
Angelini, L; Marinazzo, D; Nitti, L; Pellicoro, M; Pinna, G D; Stramaglia, S; Tupputi, S A
We present the multiscale entropy analysis of short term physiological time series of simultaneously acquired samples of heart rate, blood pressure and lung volume, from healthy subjects and from subjects with Chronic Heart Failure. Evaluating the complexity of signals at the multiple time scales inherent in physiologic dynamics, we find that healthy subjects show more complex time series at large time scales; on the other hand, at fast time scales, which are more influenced by respiration, the pathologic dynamics of blood pressure is the most random. These results robustly separate healthy and pathologic groups. We also propose a multiscale approach to evaluate interactions between time series, by performing a multivariate autoregressive modelling of the coarse grained time series: this analysis provides several new quantitative indicators which are statistically correlated with the pathology.
Zuckerwar, A. J.; Pretlow, R. A.; Stoughton, J. W.; Baker, D. A.
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.
Lee, Sanghoon; Lee, Myeong Soo; Choi, Jun-Yong; Lee, Seung-Won; Jeong, Sang-Yong; Ernst, Edzard
Acupuncture has been reported to affect the autonomic system. Currently, there are no systematic reviews examining the effect of acupuncture on HRV available in the literature. Therefore, the aim of this systematic review was to summarize and critically assess the effects of acupuncture on heart rate variability. We searched the literature using 14 databases for articles published from the earliest available publications until October 2009 without language restrictions. We included randomized clinical trials (RCTs) comparing acupuncture and sham acupuncture. The risk of bias in each study was assessed using the Cochrane criteria. Twelve RCTs met all of the inclusion criteria. One RCT evaluated the effects of acupuncture in patients with minor depression or anxiety disorders and another RCT examined the effect of acupuncture on migraine patients. Another four RCTs tested the effects of acupuncture in healthy subjects who were exposed to several conditions, including mental stress, fatigue from driving, and caffeine intake. The remaining six RCTs assessed the effects of acupuncture on healthy subjects in a normal state without any stressors. Five RCTs found significant differences in HRV between patients treated with acupuncture versus those treated with sham acupuncture (controls). However, the majority of the other RCTs showed inconsistent results or did not identify significant differences in HRV spectral parameters among individuals treated with acupuncture as compared to those treated with sham acupuncture. In conclusion, sham-controlled RCTs showed variable results and no clear evidence that acupuncture has any specific effects on HRV. Therefore, more rigorous research appears to be warranted. PMID:20304708
Chouchou, Florian; Desseilles, Martin
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
Tsuchiya, Naoki; Nakajima, Hiroshi; Hata, Yutaka
Among lots of vital signals, heart-rate (HR) is an important index for diagnose human's health condition. For instance, HR provides an early stage of cardiac disease, autonomic nerve behavior, and so forth. However, currently, HR is measured only in medical checkups and clinical diagnosis during the rested state by using electrocardiograph (ECG). Thus, some serious cardiac events in daily life could be lost. Therefore, a continuous HR monitoring during 24 hours is desired. Considering the use in daily life, the monitoring should be noninvasive and low intrusive. Thus, in this paper, an HR monitoring in sleep by using air pressure sensors is proposed. The HR monitoring is realized by employing the causal analysis among air pressure and HR. The causality is described by employing fuzzy logic. According to the experiment on 7 males at age 22-25 (23 on average), the correlation coefficient against ECG is 0.73-0.97 (0.85 on average). In addition, the cause-effect structure for HR monitoring is arranged by employing causal decomposition, and the arranged causality is applied to HR monitoring in a setting posture. According to the additional experiment on 6 males, the correlation coefficient is 0.66-0.86 (0.76 on average). Therefore, the proposed method is suggested to have enough accuracy and robustness for some daily use cases.
Duan, Sheng Zhong; Christe, Michael; Milstone, David S.; Mortensen, Richard M.
Muscarinic receptor-mediated cardiac parasympathetic activity is essential for regulating heart rate and heart rate variability (HRV). It has not been clear which Gi/Go protein is responsible for these effects. We addressed this question using knockout mice that lack G protein ?i2, ?i3, or ?o specifically. Unlike previously reported, our ?o-null mice had significantly more survivors with normal life span. Isolated hearts from ?o-null mice demonstrated much less sensitivity to the negative chronotropic effects of muscarinic agonist carbachol to lower heart rate at baseline and more profound under the stimulation of ?-adrenergic agonist isoproterenol. In the presence of parasympathetic activation indirectly produced by methoxamine, an ?1-adrenergic agonist, ?o-null mice showed markedly decreased HRV compared with wild type control mice. These differences in heart rate and HRV were not observed in ?i2-null or ?i3-null mice. Our findings establish an essential role for ?o G protein in the anti-adrenergic effect of carbachol on heart rate regulation. PMID:17418106
Kovács, L; T?zsér, J; Kézér, F L; Ruff, F; Aubin-Wodala, M; Albert, E; Choukeir, A; Szelényi, Z; Szenci, O
Behavioural changes before calving can be monitored on farms; however, predicting the onset of calving is sometimes difficult based only on clinical signs. Heart rate (HR) and heart rate variability (HRV) as non-invasive measures of autonomic nervous system (ANS) activity were investigated in Holstein-Friesian cows (N=20) with unassisted calvings in the periparturient period to predict the onset of calving and assess the stress associated with calving. R-R-intervals were analysed in 5-min time windows during the following three main periods of measurement: 1) between 0 and 96 h before the onset of calving restlessness (prepartum period); 2) during four stages of calving: (I) early first stage; between the onset of calving restlessness and the first abdominal contractions; (II) late first stage (between the first abdominal contractions and the appearance of the amniotic sac); (III) early second stage (between the appearance of the amniotic sac and the appearance of the foetal hooves); (IV) late second stage (between the appearance of the foetal hooves and delivery of the calf), and 3) over 48 h following calving (postpartum period). Data collected between 72 and 96 h before calving restlessness was used as baseline. Besides HR, Poincaré measures [standard deviation 1 (SD1) and 2 (SD2) and SD2/SD1 ratio], the root mean square of successive differences (RMSSD) in R-R intervals, the high-frequency (HF) component of HRV and the ratio between the low-frequency (LF) and the HF components (LF/HF ratio) were calculated. Heart rate increased only following the onset of the behavioural signs, peaked before delivery of the calf, then decreased immediately after calving. Parasympathetic indices of HRV (RMSSD, HFnorm and SD1) decreased, whereas sympathovagal indices (LF/HF ratio and SD2/SD1 ratio) increased significantly from baseline between 12 and 24 before the onset of calving restlessness. The same pattern was observed between 0 and 1h before calving restlessness. Following the onset of behavioural signs, parasympathetic activity increased gradually with a parallel shift in sympathovagal balance towards parasympathetic tone, which was possibly a consequence of oxytocin release, which induces an increase in vagus nerve activity. Parasympathetic activity decreased rapidly between 0 and 0.5h following calving and was lower than measured during all other stages of the study, while sympathetic activity peaked during this stage and was higher than measured during any other stages. Between 0 and 4h after calving vagal tone was lower than baseline, whereas sympathovagal balance was higher, reflecting a prolonged physiological challenge caused by calving. Vagal activity decreased, whereas sympathovagal balance shifted towards sympathetic tone with increased live body weight of the calf during the late second stage of calving, suggesting higher levels of stress associated with the higher body weight of calves. All HRV indices, measured either at the late second stage of calving and between 12 and 24h after calving, were affected by the duration of calving. Our results indicate that ANS activity measured by HRV indices is a more immediate indicator of the onset of calving than behaviour or HR, as it changed earlier than when restlessness or elevation in HR could be observed. However, because of the possible effects of other physiological mechanisms (e.g. oxytocin release) on ANS activity it seems to be difficult to measure stress associated with calving by means of HRV between the onset of calving restlessness and delivery. Further research is needed to enable more precise interpretation of the prepartum changes in HR and HRV in dairy cattle. PMID:25449409
Judith A. Leech
Study Objectives: To demonstrate that fetal heart rate measured by ultrasound can be successfully captured and monitored throughout the nocturnal polysomnogram. Methods: Fetal heart rate by ultrasound using an abdominal belt (Hewlett Packard Fetal Monitor 8040A) was measured during 1 over- night polysomnogram in volunteers in late pregnancy and added to a digitized polysomnography system (Alice 4, Respironics) Results: In
Masahiro Shiba; Akihiko Kikuchi; Tiejun Miao; Kikue Hara; Sorahiro Sunagawa; Shiro Yoshida; Kimiyo Takagi; Nobuya Unno
Aims: To examine whether the heart rate dynamics of a monochorionic diamniotic (MD) twin fetus is different from a dichorionic diamniotic (DD) twin fetus by nonlinear methods of time series analysis. Methods: 32 fetal heart rate (FHR) recordings from healthy MD twin fetuses and 58 recordings from healthy DD twin fetuses were used. Nonlinear analyses included attractor reconstruction, calculation of
Van Hecke, Amy Vaughan; Lebow, Jocelyn; Bal, Elgiz; Lamb, Damon; Harden, Emily; Kramer, Alexis; Denver, John; Bazhenova, Olga; Porges, Stephen W.
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…
The cardiovascular response in children to morning nutrition has received little attention, and associated gender-related effects are virtually uninvestigated. This study evaluated resting heart-rate (HR) and heart-rate variability (HRV) in preadolescents after overnight fasting and again after eati...
Farrell, S. W.
Examination of differences in maximal heart rate and treadmill time among three ethnic groups revealed no significant age-adjusted differences among white, black, and Mexican-American males, and suggested that black females' lower maximal heart rate may be explained by their lower cardiovascular fitness level when compared to those of other…
Sharpley, Christopher F.
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)
Effects of Smoking Cessation on Heart Rate Variability Among Long-Term Male Smokers Christopher B Cigarette smoking has been shown to adverse- ly affect heart rate variability (HRV), suggesting dysregula- tion of cardiac autonomic function. Conversely, smoking cessation is posited to improve cardiac
Prehospital Heart Rate and Blood Pressure Increase the Positive Predictive Value of the Glasgow mortality risk. Key words: blood pressure; Glasgow Coma Scale; heart rate; prehospital; traumatic brain. Previously, abnormally low and high blood pressures have both been associated with higher mortality
G. W. B. Näring; C. P. F. van der Staak
While the ability to estimate heart rate in a laboratory setting appears to be related to anxiety and alexithymia, it is still unclear how the ability to estimate blood pressure is related to these psychological measures. The perception of heart rate and blood pressure in 24 normotensive subjects with varying degrees of alexithymia and anxiety was examined. Results indicate that
Jonathan D. Wiles; Simon R. Allum; Damian A. Coleman; Ian L. Swaine
Currently, it is not possible to prescribe isometric exercise at an intensity that corresponds to given heart rates or systolic blood pressures. This might be useful in optimizing the effects of isometric exercise training. Therefore, the aim of this study was to explore the relationships between isometric exercise intensity and both heart rate and systolic blood pressure during repeated incremental
Marla J. De Jong; Debra K. Moser; Kyungeh An; Misook L. Chung
Background: Accurate assessment of anxiety in cardiac patients is important because anxiety is associated with adverse outcomes. Clinicians often use heart rate and blood pressure as indicators of anxiety; however, little is known about whether these measures accurately reflect anxiety in acutely ill patients. Aims: The purpose of this study was to determine whether heart rate and blood pressure were
Olufsen, Mette Sofie
uses blood pressure as an input to predict baroreflex firing-rate, which in turn is used to predict the periphery to the heart is decreased. These processes in turn affect beat-to-beat blood pressureORIGINAL PAPER Modeling Heart Rate Regulation--Part I: Sit-to-stand Versus Head-up Tilt Mette S
A. Sato; Y. Sato; R. F. Schmidt
In cats anaesthetized with chloralose and urethane algesic substances were injected intra-arterially into muscles of the left hindlimb and the resulting changes in heart rate and blood pressure recorded. The vagus nerves and both carotid sinus nerves were cut. Injection of KCl regularly induces acceleration of the heart rate and an increase in blood pressure. With bradykinin both accelerations and
L. C. Michelini
The present article contains a brief review on the role of vasopressinergic projections to the nucleus tractus solitarii in the genesis of reflex bradycardia and in the modulation of heart rate control during exer- cise. The effects of vasopressin on exercise tachycardia are discussed on the basis of both the endogenous peptide content changes and the heart rate response changes
Katsuyuki Murata; Eiji Yano; Hideki Hashimoto; Kanae Karita; Miwako Dakeishi
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
Phyllis K. Stein; Ali A. Ehsani; Peter P. Domitrovich; Robert E. Kleiger; Jeffrey N. Rottman
Objective To determine the effect of exercise training on cardiac autonomic modulation in normal older adults by using analysis of heart rate variability. Subjects The exercise group consisted of 7 men and 9 women aged 66 ± 4 years. The comparison group consisted of 7 men and 9 women also aged 66 ± 4 years. Method Heart rate variability was
R Beasley; D A Smith; D J McHaffie
Heart rate at rest and during increasing workloads was measured in a double blind study of 12 patients with chronic atrial fibrillation when serum concentrations of digoxin were nil and at low and high therapeutic values. Twelve normal subjects were studied for comparison. The heart rate at all levels of exercise in most patients with atrial fibrillation was not adequately
C HRISTOPHER R. C OLE; E UGENE H. B LACKSTONE; J. P ASHKOW; C LAIRE E. S NADER; S. L AUER
A BSTRACT Background The increase in heart rate that accom- panies exercise is due in part to a reduction in vagal tone. Recovery of the heart rate immediately after exercise is a function of vagal reactivation. Because a generalized decrease in vagal activity is known to be a risk factor for death, we hypothesized that a de- layed fall in
A F Rickards; J Norman
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
Ortiz, Jame; Raine, Adrian
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…
Kirk, P M; Sullman, M J
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), ratio of working heart rate to resting heart rate and 50% level indices, the mean working heart rate (HRw) of 106 bt. min(-1) +/- 6.9 (mean +/- SD) placed choker setting in the moderate workload category. The specific tasks of line shifts (120.3 +/- 4.8 bt. min(-1)), hooking up drags (118.8 +/- 6.6 bt. min(-1)) and uphill travel (126.1 +/- 12.9 bt. min(-1)), imposed the most severe workloads on the choker setters. This research also demonstrated that heart rate indices could be used as an effective means of determining the physiological strain of subjects working in New Zealand's commercial forest harvesting operations. PMID:11461040
Daniel G. Carey; German J. Pliego; Robert L. Raymond
There is perhaps no greater controversy in exercise physiology than the validity, or lack thereof, of the heart rate breakpoint theory in general, and the Conconi test in particular, in assessing the anaerobic threshold. Three heart rate breakpoint methods have been proposed as methods of detecting the anaerobic threshold have appeared in the literature: (1) a breakpoint in linearity of
Pavel Stejskal; Jana Rechbergová; Jirí Salinger; Radim Šlachta; Milan Elfmark; Martn Kalina; Radim Jur?a; Iva Rehová
Power spectral analysis of heart rate variability (HRV) has been estimated by means of a Fourier transform method at rest in seven healthy men and three women, during a 30?minutes steady state cycle exercise test at 40%, 50%, 60%, 70% and 80% respectively, of maximal heart rate reserve (MHRR) defined as (HRmax ? HRrest). Total power (PT) of HRV was
Gao, Zan; Hannon, James C.; Carson, Russell L.
The purpose of this study was to determine if students' heart rate outcomes in physical education varied as a function of activity and grade. A total of 146 sixth to eighth graders participated in different activities (i.e., walking/jogging, line dancing, soccer, and catch ball). Their average heart rate (AHR) and percentage of time in and above…
Zamuner, Antonio Roberto; Cunha, Andrea Baraldi; da Silva, Ester; Negri, Ana Paola; Tudella, Eloisa; Moreno, Marlene Aparecida
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…
Stadler, Christina; Grasmann, Dorte; Fegert, Jorg M.; Holtmann, Martin; Poustka, Fritz; Schmeck, Klaus
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…
Nelson, Larry; Evans, Melissa; Guess, Wendy; Morris, Mary; Olson, Terry; Buckwalter, John
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…
Yvonne Tran; Nirupama Wijesuriya; Mika Tarvainen; Pasi Karjalainen; Ashley Craig
Fatigue is a prevalent problem in the workplace and a common symptom of many diseases. However, its relationship with the autonomic nervous system, specifically with sympathetic arousal, needs clarification. The objective of this study was to determine the association between fatigue and heart rate variability (HRV). HRV is regarded as an indicator of the autonomic regulation activity of heart rate,
N Jafarnia Dabanloo; S. Moharreri; S. Parvaneh; A. M. Nasrabadi
The nonlinear analysis of Heart Rate Variability (HRV) is a valuable tool in both clinical practice and physiological research reflecting the ability of the cardiovascular system. Poincare plot is a geometrical representation of RR time series to demonstrate patterns of heart rate dynamics resulting from nonlinear processes. In this paper, by using Poincare plot points we introduced a novel mapping
Brian J. Young; Robert N. Leaton
The present study examined the extent to which heart rate changes evoked by acoustic startle stimuli are affected by the development of fear during startle testing. The phasic heart rate responses of rats elicited by a 120-dB startle stimulus were characterized by decelerations that habituated across trials and accelerations that developed across trials in a manner that paralleled the development
André E. Aubert; Bart Verheyden; Frank Beckers; Jan Tack; Joris Vandenberghe
Objective: This study examined the effects of hypnosis on autonomic cardiac control. We hypothesized a modification of autonomic modulation of the heart rate with an enhanced vagal tone during hypnosis compared to baseline. Methods: In 12 healthy subjects (6 men and 6 women, 22.2 ± 1.0 years of age) ECG was recorded at baseline and during hypnosis. Heart rate variability
L. T. LaCount; V. Napadow; B. Kuo; J. Kim; E. N. Brown; R. Barbieri
A visual display of stripes was used to examine cardiovagal response to motion sickness. Heart rate variability (HRV) was investigated using dynamic methods to discern instantaneous fluctuations in reaction to stimulus and perception-based events. A novel point process adaptive recursive algorithm was applied to the R-R series to compute instantaneous heart rate, HRV, and high frequency (HF) power as a
Baum, K.; Essfeld, D.; Stegemann, J.
To investigate the effect of ?g-induced peripheral extracellular fluid reductions on heart rate and blood pressure during isometric exercise, six healthy male subjects performed three calf ergometer test with different extracellular volumes of working muscles. In all tests, body positions during exercise were identical (supine with the knee joint flexed to 900). After a pre-exercise period of 25 min, during which calf volumes were manipulated, subjects had to counteract an external force of 180 N for 5 min. During the pre-exercise period three different protocols were applied. Test A: Subjects rested in the exercise position; test B: Body position was the same as in A but calf volume was increased by venous congestion (cuffs inflated to 80 mm Hg); test C: Calf volumes were decreased by a negative hydrostatic pressure (calves about 40 cm above heart level with the subjects supine). To clamp the changed calf volumes in tests B and C, cuffs were inflated to 300 mm Hg 5 min before the onset of exercise. This occlusion was maintained until termination of exercise. Compared to tests A and B, the reduced volume of test C led to significant increases in heart rate and blood pressure during exercise. Oxygen uptake did not exceed resting levels in B and C until cuffs were deflated, indicating that exclusively calf muscles contributed to the neurogenic peripheral drive. It is concluded that changes in extracellular muscle volume have to be taken into account when comparing heart rate and blood pressure during lg- and ?g- exercise.
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
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
O. V. Kuznetsova; V. D. Son’kin
Spectral analysis was performed to assess the periodic variations in the heart rate (HR), blood pressure (BP), and respiratory volume (RV) in 8- to 11- year-old children at rest. Age- and gender-related differences were revealed in the total power and spectral components of the HR, BP, and RV spectra.
Kärki, S; Lekkala, J
In this paper we propose a new simple method to measure the heart rate of a person sitting on a chair or lying in a bed. The heart rate is measured with a thin sensor pad consisting of separate electromechanical film (EMFi) and polyvinylidenefluoride (PVDF) transducers located beneath the leg of chair or bed. This study aims to evaluate the operation of the sensor system with measurements, and also to compare the results provided by the two transducer materials. Based on the results obtained here, the heart rates measured with the transducers mainly corresponded to the values of reference ECG signal. Some minor differences between the heart rate values of PVDF and EMFi appeared, especially in supine position, possible due to the material sensitivities to different force directions. However, to conclude, both materials seem to be convenient for this kind of measurement of heart rate. PMID:19591050
Baumert, Mathias; Brechtel, Lars M; Lock, Juergen; Voss, Andreas; Abbott, Derek
Scaling analysis of heart rate time series has emerged as a useful tool for the assessment of autonomic cardiac control. We investigate the heart rate time series of ten athletes (five males and five females), by applying detrended fluctuation analysis (DFA). High resolution ECGs are recorded under standardized resting conditions over 30 min and subsequently heart rate time series are extracted and artifacts filtered. We find three distinct regions of scale invariance, which correspond to the well-known VLF, LF and HF bands in the power spectra of heart rate variability. The scaling exponents alpha are alpha(HF): 1.15 [0.96-1.22], alpha(LF): 0.68 [0.57-0.84], alpha(VLF): 0.83[0.82-0.99], p < 10(-5)). In conclusion, DFA scaling exponents of heart rate time series should be fitted to the VLF, LF and HF ranges, respectively. PMID:16868343
Jauchem, J R; Frei, M R; Heinmets, F
Effects of intermittent exposure to 5.6-GHz radiofrequency radiation (RFR) on heart rate, blood pressure, and respiratory rate were examined in anesthetized rats. During exposure to 60 mW/cm2 which resulted in a 1 degree C change in colonic temperature, heart rate increased; the values returned to control levels after exposure was discontinued. No changes in mean arterial blood pressure or in respiratory rate were observed. Exposure to 30 mW/cm2 caused no significant changes in heart rate, blood pressure, or respiratory rate. The data indicate that heart rate changes during exposure to 5.6-GHz RFR are related to the average power density applied, and thus to the rate of change in temperature, and not simply to the absolute change in temperature. PMID:6514713
Dutra, Rosane Menezes Faria; Neves, Itamara Lucia Itagiba; Neves, Ricardo Simőes; Atik, Edmar; de Paula Santos, Ubiratan
OBJECTIVES: In this observational study, we evaluated the peripheral oxygen saturation (SpO2), heart rate, and blood pressure of children with cyanotic congenital heart disease who were undergoing dental extraction. METHODS: Forty-four patients between the ages of 6 and 12 years who underwent upper primary tooth extraction were included in the study. Of these, 20 patients were in the cyanotic congenital heart disease group and 24 were in the control group. RESULTS: Peripheral oxygen saturation, heart rate, and systolic blood pressure in the cyanotic congenital heart disease group varied quite significantly during the treatment protocol (p<0.05), with values of 80.5% (±7.6) to 82.8% (±7.8), 95.3 beats per minute (bpm) (±11.3) to 101.3 bpm (±9.8), and 93.6 mm Hg (±13,3) to 103.8 mm Hg (±12.7), respectively. The variations in the control group during the procedure were also significant. CONCLUSIONS: The changes observed during the study protocol, although statistically significant, were mild and lacked clinical relevance. The results indicate that dental treatment of children with cyanotic heart disease using a standardized protocol in decentralized offices without the support of a surgical center is safe. PMID:24838895
Dehkordi, Parastoo; Garde, Ainara; Karlen, Walter; Wensley, David; Ansermino, J Mark; Dumont, Guy A
Heart Rate Variability (HRV), the variation of time intervals between heartbeats, is one of the most promising and widely used quantitative markers of autonomic activity. Traditionally, HRV is measured as the series of instantaneous cycle intervals obtained from the electrocardiogram (ECG). In this study, we investigated the estimation of variation in heart rate from a photoplethysmography (PPG) signal, called pulse rate variability (PRV), and assessed its accuracy as an estimate of HRV in children with and without sleep disordered breathing (SDB). We recorded raw PPGs from 72 children using the Phone Oximeter, an oximeter connected to a mobile phone. Full polysomnography including ECG was simultaneously recorded for each subject. We used correlation and Bland-Altman analysis for comparing the parameters of HRV and PRV between two groups of children. Significant correlation (r > 0.90, p < 0.05) and close agreement were found between HRV and PRV for mean intervals, standard deviation of intervals (SDNN) and the root-mean square of the difference of successive intervals (RMSSD). However Bland-Altman analysis showed a large divergence for LF/HF ratio parameter. In addition, children with SDB had depressed SDNN and RMSSD and elevated LF/HF in comparison to children without SDB. In conclusion, PRV provides the accurate estimate of HRV in time domain analysis but does not reflect precise estimation for parameters in frequency domain. PMID:24111246
Fei, L.; Anderson, M. H.; Katritsis, D.; Sneddon, J.; Statters, D. J.; Malik, M.; Camm, A. J.
BACKGROUND--Although heart rate variability has already been studied in survivors of sudden cardiac death secondary to coronary artery disease, an assessment of heart rate variability in survivors of sudden cardiac death not associated with coronary artery disease has not been made. METHODS--10 patients with aborted sudden cardiac death not associated with coronary artery disease (seven patients with primary ventricular fibrillation and three with unclassified mild cardiomyopathy) underwent two channel 24 hour Holter monitoring in a drug free state. All subjects were in sinus rhythm and had normal atrioventricular conduction and normal cardiac function. Spectral heart rate variability was analysed on a Holter analysis system and was expressed as total (0.01-1.00 Hz), low (0.04-0.15 Hz) and high (0.15-0.40 Hz) frequency components for each hour. Heart rate variability index was calculated for the 24 hour periods. 10 age and sex matched healthy subjects were taken as a control group. RESULTS--The spectral heart rate variability over 24 hours was significantly lower in survivors of sudden cardiac death than in controls (total 38(15) v 48(14) ms; low, 25(11) v 32(13) ms; and high, 13(8) v 18(8) ms; p < 0.05 for all comparisons). The differences in the ratio of low/high (2.19(0.76) v 1.98(0.50), p = 0.132), mean heart rate (77(12) v 69(12) beats/min, p = 0.070), and heart rate variability index (38(12) v 44(16), p = 0.287) over 24 hours between survivors of sudden cardiac death and controls did not reach significance. Comparisons of the hourly heart rate variability over the 24 hour period between the two groups showed that the differences in all components of heart rate variability, low/high ratio and mean heart rate were highly significant. Furthermore, there was no significant difference in the maximum hourly heart rate variability over the 24 hour period. The minimum hourly heart rate variability was, however, significantly lower in survivors of sudden cardiac death than in controls (total, 20(8) v 28(4) ms; low, 12(6) v 17(3) ms; high, 6(2) v 8(2) ms; p < 0.05 for all comparisons). CONCLUSIONS--These findings suggest that there is abnormal autonomic influence on the heart in patients without coronary artery disease at risk of sudden cardiac death. Hourly analysis of heart rate variability throughout the 24 hour period may provide additional information important in the identification of high risk patients. PMID:8297686
Vybiral, T.; Glaeser, D. H.; Goldberger, A. L.; Rigney, D. R.; Hess, K. R.; Mietus, J.; Skinner, J. E.; Francis, M.; Pratt, C. M.
OBJECTIVES. The purpose of this report was to study heart rate variability in Holter recordings of patients who experienced ventricular fibrillation during the recording. BACKGROUND. Decreased heart rate variability is recognized as a long-term predictor of overall and arrhythmic death after myocardial infarction. It was therefore postulated that heart rate variability would be lowest when measured immediately before ventricular fibrillation. METHODS. Conventional indexes of heart rate variability were calculated from Holter recordings of 24 patients with structural heart disease who had ventricular fibrillation during monitoring. The control group consisted of 19 patients with coronary artery disease, of comparable age and left ventricular ejection fraction, who had nonsustained ventricular tachycardia but no ventricular fibrillation. RESULTS. Heart rate variability did not differ between the two groups, and no consistent trends in heart rate variability were observed before ventricular fibrillation occurred. CONCLUSIONS. Although conventional heart rate variability is an independent long-term predictor of adverse outcome after myocardial infarction, its clinical utility as a short-term predictor of life-threatening arrhythmias remains to be elucidated.
J M Bell; E J Bassey
OBJECTIVE--To establish the accuracy of the traditional method of measuring the intensity of exercise in aerobic dance classes, that is, intermittent pulse palpation performed during a brief cessation of activity. METHODS--A short wave telemetry system was used to record heart rates during a class in a group of 12 healthy women aged 26 (SD 6) years. Subjects palpated their pulses
Faizan Javed; Andrey V. Savkin; Gregory S. H. Chan; Paul M. Middleton; Philip Malouf; Elizabeth Steel; James Mackie; Nigel H. Lovell
This study aims to assess the blood volume and heart rate (HR) responses during haemodialysis in fluid overloaded patients by a nonparametric nonlinear regression approach based on a support vector machine (SVM). Relative blood volume (RBV) and electrocardiogram (ECG) was recorded from 23 haemodynamically stable renal failure patients during regular haemodialysis. Modelling was performed on 18 fluid overloaded patients (fluid
Kristen A Sethares; Kathleen Elliott
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).
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
Joanne B. Ditewig; Helene Blok; Jeroen Havers; Haske van Veenendaal
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.
Lipsitz, L. A.; Hashimoto, F.; Lubowsky, L. P.; Mietus, J.; Moody, G. B.; Appenzeller, O.; Goldberger, A. L.
OBJECTIVE--To investigate the alterations in autonomic control of heart rate at high altitude and to test the hypothesis that hypoxaemic stress during exposure to high altitude induces non-linear, periodic heart rate oscillations, similar to those seen in heart failure and the sleep apnoea syndrome. SUBJECTS--11 healthy subjects aged 24-64. MAIN OUTCOME MEASURES--24 hour ambulatory electrocardiogram records obtained at baseline (1524 m) and at 4700 m. Simultaneous heart rate and respiratory dynamics during 2.5 hours of sleep by fast Fourier transform analysis of beat to beat heart rate and of an electrocardiographically derived respiration signal. RESULTS--All subjects had resting hypoxaemia at high altitude, with an average oxyhaemoglobin saturation of 81% (5%). There was no significant change in mean heart rate, but low frequency (0.01-0.05 Hz) spectral power was increased (P < 0.01) at high altitude. Time series analysis showed a complex range of non-linear sinus rhythm dynamics. Striking low frequency (0.04-0.06 Hz) heart rate oscillations were observed during sleep in eight subjects at high altitude. Analysis of the electrocardiographically derived respiration signal indicated that these heart rate oscillations correlated with low frequency respiratory oscillations. CONCLUSIONS--These data suggest (a) that increased low frequency power during high altitude exposure is not simply attributable to increased sympathetic modulation of heart rate, but relates to distinctive cardiopulmonary oscillations at approximately 0.05 Hz and (b) that the emergence of periodic heart rate oscillations at high altitude is consistent with an unstable cardiopulmonary control system that may develop on acute exposure to hypoxaemic stress.
Cavallari, Jennifer M; Fang, Shona C; Mittleman, Murray A; Christiani, David C
Objective To compare the circadian variation of hourly heart rate variability (HRV) on work and non-workdays among boilermaker construction workers. Method A panel study of 18 males monitored by 24-h ambulatory ECG over 44 observation-days on paired work and non-workdays was conducted. ECGs were analysed and the SD of normal-to-normal beats index (SDNNi) was calculated from 5-min data and summarised hourly. SDNNis over work and non-workdays were compared using linear mixed-effects models to account for repeated measures and harmonic regression to account for circadian variation. Results Both work and non-work hourly HRV exhibited circadian variation with an increase in the evening and a decrease in the afternoon. SDNNi was lower on workdays as compared with non-workdays with the largest, statistically significant differences observed between 10:00 and 16:00, during active working. Lower SDNNi, albeit smaller yet statistically significant differences, was also observed in the evening hours following work (17:00–21:00) and early morning (4:00). In regression models using all time periods, an average workday SDNNi was 8.1 ms (95% CI –9.8 to –6.3) lower than non-workday SDNNi. The circadian pattern of HRV exhibited two peaks which differed on work and non-workdays. Conclusion While workday and non-workday HRV followed a circadian pattern, decreased HRV and variation of the circadian pattern were observed on workdays. Declines and changes in the circadian pattern of HRV is a concern among this exposed population. PMID:20798005
Orlov, Steven; Bril, Vera; Orszag, Andrej; Perkins, Bruce A.
OBJECTIVE Reduced heart rate variability (HRV) is classically viewed as an early phenomenon in diabetic sensorimotor polyneuropathy (DSP). We aimed to determine the characteristics of HRV across the spectrum of clinical DSP in type 1 diabetes. RESEARCH DESIGN AND METHODS Eighty-nine diabetic subjects and 60 healthy volunteers underwent assessment of RR interval variation (RRvar) during deep breathing and clinical and electrophysiological examination. We examined the distribution of age-standardized RRvar across the spectrum of clinical DSP, identified variables associated with RRvar in multivariate regression, and compared RRvar with validated measures of neuropathy. RESULTS Age-standardized RRvar had a significant, step-wise, inverse relationship with ordinal categories of increasing DSP severity (? = ?5.4, P < 0.0001) among subjects with diabetes. Case subjects with DSP had substantially lower age-standardized RRvar compared with diabetic control subjects without DSP (? = ?5.2, P < 0.01), although there was substantial overlap of RRvar between diabetic case subjects and control subjects and the healthy volunteer cohort. In multivariate analysis, advanced age was independently associated with lower RRvar in both healthy volunteers and diabetic subjects, whereas higher glycated hemoglobin A1c and systolic blood pressure were independently associated with lower RRvar in diabetic subjects. RRvar had a significant association with validated measures of large and small fiber neuropathy. CONCLUSIONS HRV may be a biomarker for clinical DSP and is associated cross-sectionally with both early and late measures of neuropathy. The low HRV observed in some control subjects without DSP and in most case subjects with severe DSP may signify that HRV has different prognostic implications in these groups, requiring further longitudinal study. PMID:22357183