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Sample records for heart rate metabolic

  1. Increased heart rate variability but normal resting metabolic rate in hypocretin/orexin-deficient human narcolepsy.

    NARCIS (Netherlands)

    Fronczek, R.; Overeem, S.; Reijntjes, R.; Lammers, G.J.; Dijk, J.G.M.; Pijl, H.

    2008-01-01

    STUDY OBJECTIVES: We investigated autonomic balance and resting metabolic rate to explore their possible involvement in obesity in hypocretin/orexin-deficient narcoleptic subjects. METHODS: Resting metabolic rate (using indirect calorimetry) and variability in heart rate and blood pressure were

  2. Hydration status after exercise affect resting metabolic rate and heart rate variability.

    Science.gov (United States)

    Castro-Sepulveda, Mauricio; Cerda-Kohler, Hugo; Pérez-Luco, Cristian; Monsalves, Matías; Andrade, David Cristobal; Zbinden-Foncea, Herman; Báez-San Martín, Eduardo; Ramírez-Campillo, Rodrigo

    2014-12-17

    Heart rate variability and resting metabolic rate are commonly to assess athlete's physiological status and energy requirements. Exercise-induced dehydration can reach up to 5% of body mass per hour. Consequently, dehydration may have a profound physiological effect on human's homeostasis. To compare the effects of dehydration and rehydration after exercise on heart rate variability and resting metabolic rate in college athletes. 14 college athletes were divided into a dehydration group (n=7) and a rehydration group (n=7), both submitted to basal (T1) heart rate variability and resting metabolic rate measurements. After basal measurements both groups were actively dehydrated (-3.4 ± 0.4% of body mass for both groups). Afterwards, dehydration group rested, while rehydration group receive a fluid intake (during a 3 h period) equivalent to 150% of body mass loss achieved during active dehydration. Four hours after active dehydration heart rate variability and resting metabolic rate were re-assessed (T2). At T2 both rehydration group (+13%) and dehydration group (+30%) achieve a significant (prate, however, only dehydration group ..showed a significant reduction in heart rate variability. More so, the change in resting metabolic rate was significantly higher in dehydration group compared to rehydration group. Hydric homeostasis after exercise affects resting metabolic rate and heart rate variability, highlighting the necessity to control hydration state before resting metabolic rate and heart rate variability assessment. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

  3. Increased heart rate variability but normal resting metabolic rate in hypocretin/orexin-deficient human narcolepsy.

    NARCIS (Netherlands)

    Fronczek, R.; Overeem, S.; Reijntjes, R.; Lammers, G.J.; Dijk, J.G.M.; Pijl, H.

    2008-01-01

    STUDY OBJECTIVES: We investigated autonomic balance and resting metabolic rate to explore their possible involvement in obesity in hypocretin/orexin-deficient narcoleptic subjects. METHODS: Resting metabolic rate (using indirect calorimetry) and variability in heart rate and blood pressure were dete

  4. Assesment of Autonomic Function in Metabolic Syndrome using Combination Heart Rate Variability and Heart Rate Turbulence

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    Gülay Aydın

    2013-12-01

    Full Text Available INTRODUCTION: Metabolic syndrome (MetS is described as a group of various abnormal metabolic risk factors such as obesity, dyslipidemia, increased blood pressure, increased plasma glucose levels, prothrombotic condition and proinflammatory state. These parameters are related to decreased parasympathetic and increased sympathetic activity. We aimed to evaluate autonomic function using a combination with heart rate variability (HRV and heart rate turbulence (HRT in metabolic syndrome to compare non-metabolic syndrome(non-MetS. METHODS: We selected consecutive 50 patients with MetS and 50 patients with healthy non-MetS individuals. All patients underwent 24 hours holter monitoring to evaluate HRT and HRV parameters. RESULTS: Age of patients was not different in two groups. Mean age of MetS patients was 57,50±12,13 and 54,6±10,25 in non- MetS individuals. Sex of patients was non different in MetS compared to non-MetS (37 female and 13 male vs. 22 female, 28 male p<0,05 respectively. SDNN and RMSSD was lower in MetS compared to those without MetS (131,96±49,12 vs 179,59±85,83 p=0,03 and 78,64±35,22 vs 112,73±81,24 p=0,08 respectively. SDANN, pNN50,Mean RR, mean heart rate, count of ventricular premature complex(VPC were not different between two groups. Turbulence Slope(TS was not different in two groups. Turbulence Onset(TO was higher in MetS compared to non-MetS (2,01±15,29 and -6,21±13,5 p=0,005. DISCUSSION AND CONCLUSION: We showed that autonomic function in MetS was impaired using a combination with HRT and HRV. These patients should be followed closely for adverse cardiovascular outcome especially including cardiac arrhythmia.

  5. Assessing Metabolic Syndrome Through Increased Heart Rate During Exercise.

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    Sadeghi, Masoumeh; Gharipour, Mojgan; Nezafati, Pouya; Shafie, Davood; Aghababaei, Esmaeil; Sarrafzadegan, Nizal

    2016-11-01

    The present study aimed to assess changes in resting and maximum heart rates as primary indicators of cardiac autonomic function in metabolic syndrome (MetS) patients and to determine their value for discriminating MetS from non-MetS. 468 participants were enrolled in this cross-sectional study and assessed according to the updated adult treatment panel III (ATP-III) definition of MetS. Resting and maximum heart rates were recorded following the Bruce protocol during an exercise. A receiver operating characteristic (ROC) curve was used to identify the best cutoff point for discriminating MetS from the non-MetS state. 194 participants (41.5%) were diagnosed as MetS. The mean resting heart rate (RHR) was not statistically different between the two groups (P=0.078). However, the mean maximum heart (MHR) rate was considerably higher in participants with MetS (142.37±14.84 beats per min) compared to the non-MetS group (134.62±21.63 beats per min) (P<0.001). In the MetS group, the MHR was positively correlated with the serum triglyceride level (β=0.185, P=0.033) and was inversely associated with age (β=-0.469, P<0.001). The MHR had a moderate value for discriminating MetS from the non-MetS state (c=0.580, P=0.004) with the optimal cutoff point of 140 beats per min. In MetS patients, the MHR was significantly greater compared to non-MetS subjects and was directly correlated with serum triglyceride levels and inversely with advanced age. Moreover, MHR can be used as a suspicious indicator for identifying MetS.

  6. Assessing Metabolic Syndrome Through Increased Heart Rate During Exercise

    Directory of Open Access Journals (Sweden)

    Masoumeh Sadeghi

    2016-12-01

    Full Text Available The present study aimed to assess changes in resting and maximum heart rates as primary indicators of cardiac autonomic function in metabolic syndrome (MetS patients and to determine their value for discriminating MetS from non-MetS. 468 participants were enrolled in this cross-sectional study and assessed according to the updated adult treatment panel III (ATP-III definition of MetS. Resting and maximum heart rates were recorded following the Bruce protocol during an exercise. A receiver operating characteristic (ROC curve was used to identify the best cutoff point for discriminating MetS from the non-MetS state. 194 participants (41.5% were diagnosed as MetS. The mean resting heart rate (RHR was not statistically different between the two groups (P=0.078. However, the mean maximum heart (MHR rate was considerably higher in participants with MetS (142.37±14.84 beats per min compared to the non-MetS group (134.62±21.63 beats per min (P<0.001. In the MetS group, the MHR was positively correlated with the serum triglyceride level (β=0.185, P=0.033 and was inversely associated with age (β=-0.469, P<0.001. The MHR had a moderate value for discriminating MetS from the non-MetS state (c=0.580, P=0.004 with the optimal cutoff point of 140 beats per min. In MetS patients, the MHR was significantly greater compared to non-MetS subjects and was directly correlated with serum triglyceride levels and inversely with advanced age. Moreover, MHR can be used as a suspicious indicator for identifying MetS.

  7. Heart rate variability and the metabolic syndrome: a systematic review of the literature.

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    Stuckey, Melanie I; Tulppo, Mikko P; Kiviniemi, Antti M; Petrella, Robert J

    2014-11-01

    A number of cross-sectional studies have examined associations between heart rate variability and metabolic syndrome, but differences in study populations, data collection and analysis methodologies make synthesis difficult. The purpose of this study was to systematically review published primary research examining associations between heart rate variability and metabolic syndrome or its individual risk factors. A systematic literature search of PubMed and EMBASE was conducted to identify relevant articles published from January 1999 to December 2012. Studies were included if they examined associations between heart rate variability analysed by standard protocols and metabolic syndrome risk factors according to published definitions. All papers were scored with a modified Downs and Black instrument, and data were extracted. Fourteen studies were included. Heart rate variability generally was reduced in women with metabolic syndrome compared to those without, while results in men were inconsistent. Time and frequency domain heart rate variability parameters were associated with individual metabolic syndrome risk factors, though sex differences exist. Only two studies considered nonlinear and Poincaré plot heart rate variability parameters, which were reduced in metabolic syndrome. Heart rate variability is altered differently in men and women with metabolic syndrome. Future studies should follow consistent heart rate variability analysis protocols and metabolic syndrome definitions and include more comprehensive analyses to investigate potential mechanisms. Copyright © 2014 John Wiley & Sons, Ltd.

  8. Metabolic Syndrome and Short-Term Heart Rate Variability in Adults with Intellectual Disabilities

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    Chang, Yaw-Wen; Lin, Jin-Ding; Chen, Wei-Liang; Yen, Chia-Feng; Loh, Ching-Hui; Fang, Wen-Hui; Wu, Li-Wei

    2012-01-01

    Metabolic syndrome (MetS) increases the risk of cardiovascular events. Heart rate variability (HRV) represents autonomic functioning, and reduced HRV significantly increases cardiovascular mortality. The aims of the present paper are to assess the prevalence of MetS in adults with intellectual disabilities (ID), the difference in short-term HRV…

  9. Metabolic Syndrome and Short-Term Heart Rate Variability in Adults with Intellectual Disabilities

    Science.gov (United States)

    Chang, Yaw-Wen; Lin, Jin-Ding; Chen, Wei-Liang; Yen, Chia-Feng; Loh, Ching-Hui; Fang, Wen-Hui; Wu, Li-Wei

    2012-01-01

    Metabolic syndrome (MetS) increases the risk of cardiovascular events. Heart rate variability (HRV) represents autonomic functioning, and reduced HRV significantly increases cardiovascular mortality. The aims of the present paper are to assess the prevalence of MetS in adults with intellectual disabilities (ID), the difference in short-term HRV…

  10. Running and Metabolic Demands of Elite Rugby Union Assessed Using Traditional, Metabolic Power, and Heart Rate Monitoring Methods

    Science.gov (United States)

    Dubois, Romain; Paillard, Thierry; Lyons, Mark; McGrath, David; Maurelli, Olivier; Prioux, Jacques

    2017-01-01

    The aims of this study were (1) to analyze elite rugby union game demands using 3 different approaches: traditional, metabolic and heart rate-based methods (2) to explore the relationship between these methods and (3) to explore positional differences between the backs and forwards players. Time motion analysis and game demands of fourteen professional players (24.1 ± 3.4 y), over 5 European challenge cup games, were analyzed. Thresholds of 14.4 km·h-1, 20 W.kg-1 and 85% of maximal heart rate (HRmax) were set for high-intensity efforts across the three methods. The mean % of HRmax was 80.6 ± 4.3 % while 42.2 ± 16.5% of game time was spent above 85% of HRmax with no significant differences between the forwards and the backs. Our findings also show that the backs cover greater distances at high-speed than forwards (% difference: +35.2 ± 6.6%; prunning distances of 24.8 ± 17.1% for the backs, and 53.4 ± 16.0% for the forwards with a significant difference (+29.6 ± 6.0% for the forwards; prunning distance (assessed using the traditional approach) and the high-metabolic power distance. The HR monitoring methods demonstrate clearly the high physiological demands of professional rugby games. The traditional and the metabolic-power approaches shows a close correlation concerning their relative values, nevertheless the difference in absolute values especially for the high-intensity thresholds demonstrates that the metabolic power approach may represent an interesting alternative to the traditional approaches used in evaluating the high-intensity running efforts required in rugby union games. Key points Elite/professional rugby union players Heart rate monitoring during official games Metabolic power approach PMID:28344455

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

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    Sapir, Nir; Wikelski, Martin; McCue, Marshall D.; Pinshow, Berry; Nathan, Ran

    2010-01-01

    Background Many avian species soar and glide over land. Evidence from large birds (mb>0.9 kg) suggests that soaring-gliding is considerably cheaper in terms of energy than flapping flight, and costs about two to three times the basal metabolic rate (BMR). Yet, soaring-gliding is considered unfavorable for small birds because migration speed in small birds during soaring-gliding is believed to be lower than that of flapping flight. Nevertheless, several small bird species routinely soar and glide. Methodology/Principal Findings To estimate the energetic cost of soaring-gliding flight in small birds, we measured heart beat frequencies of free-ranging migrating European bee-eaters (Merops apiaster, mb∼55 g) using radio telemetry, and established the relationship between heart beat frequency and metabolic rate (by indirect calorimetry) in the laboratory. Heart beat frequency during sustained soaring-gliding was 2.2 to 2.5 times lower than during flapping flight, but similar to, and not significantly different from, that measured in resting birds. We estimated that soaring-gliding metabolic rate of European bee-eaters is about twice their basal metabolic rate (BMR), which is similar to the value estimated in the black-browed albatross Thalassarche (previously Diomedea) melanophrys, mb∼4 kg). We found that soaring-gliding migration speed is not significantly different from flapping migration speed. Conclusions/Significance We found no evidence that soaring-gliding speed is slower than flapping flight in bee-eaters, contradicting earlier estimates that implied a migration speed penalty for using soaring-gliding rather than flapping flight. Moreover, we suggest that small birds soar and glide during migration, breeding, dispersal, and other stages in their annual cycle because it may entail a low energy cost of transport. We propose that the energy cost of soaring-gliding may be proportional to BMR regardless of bird size, as theoretically deduced by earlier studies

  12. Food composition influences metabolism, heart rate and organ growth during digestion in Python regius.

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    Henriksen, Poul Secher; Enok, Sanne; Overgaard, Johannes; Wang, Tobias

    2015-05-01

    Digestion in pythons is associated with a large increase in oxygen consumption (SDA), increased cardiac output and growth in visceral organs assisting in digestion. The processes leading to the large postprandial rise in metabolism in snakes is subject to opposing views. Gastric work, protein synthesis and organ growth have each been speculated to be major contributors to the SDA. To investigate the role of food composition on SDA, heart rate (HR) and organ growth, 48 ball pythons (Python regius) were fed meals of either fat, glucose, protein or protein combined with carbonate. Our study shows that protein, in the absence or presence of carbonate causes a large SDA response, while glucose caused a significantly smaller SDA response and digestion of fat failed to affect metabolism. Addition of carbonate to the diet to stimulate gastric acid secretion did not increase the SDA response. These results support protein synthesis as a major contributor to the SDA response and show that increased gastric acid secretion occurs at a low metabolic cost. The increase in metabolism was supported by tachycardia caused by altered autonomic regulation as well as an increased non-adrenergic, non-cholinergic (NANC) tone in response to all diets, except for the lipid meal. Organ growth only occurred in the small intestine and liver in snakes fed on a high protein diet.

  13. Running and Metabolic Demands of Elite Rugby Union Assessed Using Traditional, Metabolic Power, and Heart Rate Monitoring Methods

    Directory of Open Access Journals (Sweden)

    Romain Dubois, Thierry Paillard, Mark Lyons, David McGrath, Olivier Maurelli, Jacques Prioux

    2017-03-01

    Full Text Available The aims of this study were (1 to analyze elite rugby union game demands using 3 different approaches: traditional, metabolic and heart rate-based methods (2 to explore the relationship between these methods and (3 to explore positional differences between the backs and forwards players. Time motion analysis and game demands of fourteen professional players (24.1 ± 3.4 y, over 5 European challenge cup games, were analyzed. Thresholds of 14.4 km·h-1, 20 W.kg-1 and 85% of maximal heart rate (HRmax were set for high-intensity efforts across the three methods. The mean % of HRmax was 80.6 ± 4.3 % while 42.2 ± 16.5% of game time was spent above 85% of HRmax with no significant differences between the forwards and the backs. Our findings also show that the backs cover greater distances at high-speed than forwards (% difference: +35.2 ± 6.6%; p<0.01 while the forwards cover more distance than the backs (+26.8 ± 5.7%; p<0.05 in moderate-speed zone (10-14.4 km·h-1. However, no significant difference in high-metabolic power distance was found between the backs and forwards. Indeed, the high-metabolic power distances were greater than high-speed running distances of 24.8 ± 17.1% for the backs, and 53.4 ± 16.0% for the forwards with a significant difference (+29.6 ± 6.0% for the forwards; p<0.001 between the two groups. Nevertheless, nearly perfect correlations were found between the total distance assessed using the traditional approach and the metabolic power approach (r = 0.98. Furthermore, there is a strong association (r = 0.93 between the high-speed running distance (assessed using the traditional approach and the high-metabolic power distance. The HR monitoring methods demonstrate clearly the high physiological demands of professional rugby games. The traditional and the metabolic-power approaches shows a close correlation concerning their relative values, nevertheless the difference in absolute values especially for the high

  14. Flight modes in migrating European bee-eaters: heart rate may indicate low metabolic rate during soaring and gliding.

    Directory of Open Access Journals (Sweden)

    Nir Sapir

    Full Text Available BACKGROUND: Many avian species soar and glide over land. Evidence from large birds (m(b>0.9 kg suggests that soaring-gliding is considerably cheaper in terms of energy than flapping flight, and costs about two to three times the basal metabolic rate (BMR. Yet, soaring-gliding is considered unfavorable for small birds because migration speed in small birds during soaring-gliding is believed to be lower than that of flapping flight. Nevertheless, several small bird species routinely soar and glide. METHODOLOGY/PRINCIPAL FINDINGS: To estimate the energetic cost of soaring-gliding flight in small birds, we measured heart beat frequencies of free-ranging migrating European bee-eaters (Merops apiaster, m(b∼55 g using radio telemetry, and established the relationship between heart beat frequency and metabolic rate (by indirect calorimetry in the laboratory. Heart beat frequency during sustained soaring-gliding was 2.2 to 2.5 times lower than during flapping flight, but similar to, and not significantly different from, that measured in resting birds. We estimated that soaring-gliding metabolic rate of European bee-eaters is about twice their basal metabolic rate (BMR, which is similar to the value estimated in the black-browed albatross Thalassarche (previously Diomedea melanophrys, m(b∼4 kg. We found that soaring-gliding migration speed is not significantly different from flapping migration speed. CONCLUSIONS/SIGNIFICANCE: We found no evidence that soaring-gliding speed is slower than flapping flight in bee-eaters, contradicting earlier estimates that implied a migration speed penalty for using soaring-gliding rather than flapping flight. Moreover, we suggest that small birds soar and glide during migration, breeding, dispersal, and other stages in their annual cycle because it may entail a low energy cost of transport. We propose that the energy cost of soaring-gliding may be proportional to BMR regardless of bird size, as theoretically deduced by

  15. ASSOCIATION BETWEEN HEART RATE VARIABILITY AND COMPONENTS OF THE METABOLIC SYNDROME IN WOMEN WITH RHEUMATOID ARTHRITIS

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    D. S. Novikova

    2014-01-01

    Full Text Available Aim. To study the relationship between heart rate variability (HRV and components of the metabolic syndrome (MS in women with rheumatoid arthritis (RA.Material and methods. Female patients (n=291 with a firm RA diagnosis under 60 years of age were examined. Evaluation of traditional cardiovascular risk factors, MS components (International Diabetes Federation criteria, 24-hour ECG monitoring were performed along with the assessment of clinical symptoms, the degree of activity and severity of RA.Results. Weak associations of HRV with waist circumference, blood pressure level, hypertriglyceridemia, hypoalphalipoproteinemia and smoking were found in the correlation analysis. Patients with RA were divided into three groups depending on the number of existing MS components. Group 1 (0-1 component included 113 women (39%, group 2 (2-3 components – 109 women (37% and group 3 (4-5 components – included 69 women with RA (24%. Progressive decrease in the absolute values and the increase in the percentage of the low values of all the studied time and frequency HRV indices, adjusted by age and heart rate, from the 1st to the 3rd group of women with RA were determined. Significant increase in sympathovagal index from the 1st to the 3rd group was also shown.Conclusion. A combination of several components of the MS in RA plays a greater role in the development of disorders of neurovegetative autonomic control of heart activity (increased influence of the sympathetic and/or reduced influence of the parasympathetic nervous system on cardiac function than each traditional cardiovascular risk factor taken separately. Abnormality in autonomic regulation of cardiac activity may be an important link in the pathogenesis of cardiac arrhythmias, sudden cardiac death and overall cardiovascular mortality in women with RA.

  16. Effects of aerobic exercise on the resting heart rate, physical fitness, and arterial stiffness of female patients with metabolic syndrome.

    Science.gov (United States)

    Kang, Seol-Jung; Kim, Eon-Ho; Ko, Kwang-Jun

    2016-06-01

    [Purpose] The purpose of this study was to investigate the effects of aerobic exercise on the resting heart rate, physical fitness, and arterial stiffness or female patients with metabolic syndrome. [Subjects and Methods] Subjects were randomly assigned to an exercise group (n=12) or a control group (n=11). Subjects in the exercise group performed aerobic exercise at 60-80% of maximum heart rate for 40 min 5 times a week for 12 weeks. The changes in metabolic syndrome risk factors, resting heart rate, physical fitness, and arterial stiffness were measured and analyzed before and after initiation of the exercise program to determine the effect of exercise. Arterial stiffness was assessed based on brachial-ankle pulse wave velocity (ba-PWV). [Results] Compared to the control group; The metabolic syndrome risk factors (weight, % body fat, waist circumference, systolic blood pressure, diastolic blood pressure, and HDL-Cholesterol) were significantly improved in the exercise: resting heart rate was significantly decreased; VO2max, muscle strength and muscle endurance were significantly increased; and ba-PWV was significantly decreased. [Conclusion] Aerobic exercise had beneficial effects on the resting heart rate, physical fitness, and arterial stiffness of patients with metabolic syndrome.

  17. Effects of aerobic exercise on the resting heart rate, physical fitness, and arterial stiffness of female patients with metabolic syndrome

    OpenAIRE

    Kang, Seol-Jung; Kim, DE; Ko, Kwang-Jun

    2016-01-01

    [Purpose] The purpose of this study was to investigate the effects of aerobic exercise on the resting heart rate, physical fitness, and arterial stiffness or female patients with metabolic syndrome. [Subjects and Methods] Subjects were randomly assigned to an exercise group (n=12) or a control group (n=11). Subjects in the exercise group performed aerobic exercise at 60–80% of maximum heart rate for 40 min 5 times a week for 12 weeks. The changes in metabolic syndrome risk factors, resting he...

  18. Product of heart rate and first heart sound amplitude as an index of myocardial metabolic stress during graded exercise.

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    Tanaka, Hiroaki; Matsuda, Takuro; Tobina, Takuro; Yamada, Yousuke; Yamagishi, Tamiharu; Sakai, Hideaki; Obara, Shigeru; Higaki, Yasuki; Kiyonaga, Akira; Brubaker, Peter H

    2013-01-01

    The double product (DP) breakpoint of heart rate (HR) and systolic blood pressure has been identified as coincident with anaerobic threshold (AT), but there are no simple methods for measuring cardiac metabolic stress (CMS) during an exercise test. It was hypothesized that the DP of HR and the amplitude of the first heart sound (AHS1) (DP-AHS1) would reflect CMS, and thus, the breakpoint in the DP-AHS1 (DPBP-AHS1) could be an alternative method for determining AT. Subjects (age range, 18-73 years) were recruited to perform a graded exercise test on a cycle ergometer with continuous monitoring of DP-AHS1, with left ventricular pressure (LVP; experiment 1, Ex1), plasma catecholamine and blood lactate (experiment 2, Ex2) and gas exchange (experiment 3, Ex3). Ex1: in all subjects there was a strong correlation between AHS1 and LVdP/dtmax (r=0.94-0.98), and between the DP-AHS1 and the triple product of HR, LVdP/dtmax, and max LVP (r=0.98-0.99). Ex2: DP-AHS1 was strongly correlated with adrenaline (r=0.97-1.00) and lactate (r=0.96-1.00) levels in all subjects. Ex3: there was a strong correlation between DPBP-AHS1, AT and maximum oxygen consumption. The present simple measure of DP-AHS1 can reflect plasma adrenaline and lactate levels during graded exercise testing. Further, DPBP-AHS1 is a surrogate marker of AT and a good index of functional aerobic capacity.

  19. Excess heart rate and systolic blood pressure during psychological stress in relation to metabolic demand in adolescents

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    Cardiovascular responses during exercise are matched to the increased metabolic demand, but this may not be the case during psychological stress. No studies to date have tested this hypothesis in youth. Fifty-four youth, ages 13-16 years completed two visits. Heart rate (HR), systolic blood pressu...

  20. Metabolic energy correlates of heart rate variability spectral power associated with a 900-calorie challenge.

    Science.gov (United States)

    Millis, Richard M; Austin, Rachel E; Hatcher, Mark D; Bond, Vernon; Goring, Kim L

    2011-01-01

    We studied healthy males challenged with a 900 Cal test beverage and correlated EE with the raw (ms(2)) and normalized units (nu) of total power (TP), low frequency/high frequency (LF/HF) and VLF spectral power of heart rate variability (HRV). The correlations were evaluated during 20 min of normal breathing (NB, control) and 20 min of paced breathing (PB) at 12 breaths·min(-1) (0.2 Hz). EE was not significantly correlated with any of the HRV variables before the metabolic challenge. After the challenge, EE was positively correlated with LF/HF and with VLF; VLF was also positively correlated with LF/HF during both NB and PB. These findings suggest that EE may be a correlate of LF/HF and of VLF spectral power of HRV in healthy adolescent/young adult males. The association of lower resting energy expenditure with lower amounts of VLF spectral power may occur in individuals with predilections for obese phenotypes.

  1. Metabolic Energy Correlates of Heart Rate Variability Spectral Power Associated with a 900-Calorie Challenge

    Directory of Open Access Journals (Sweden)

    Richard M. Millis

    2011-01-01

    Full Text Available We studied healthy males challenged with a 900 Cal test beverage and correlated EE with the raw (ms2 and normalized units (nu of total power (TP, low frequency/high frequency (LF/HF and VLF spectral power of heart rate variability (HRV. The correlations were evaluated during 20 min of normal breathing (NB, control and 20 min of paced breathing (PB at 12 breaths⋅min−1 (0.2 Hz. EE was not significantly correlated with any of the HRV variables before the metabolic challenge. After the challenge, EE was positively correlated with LF/HF and with VLF; VLF was also positively correlated with LF/HF during both NB and PB. These findings suggest that EE may be a correlate of LF/HF and of VLF spectral power of HRV in healthy adolescent/young adult males. The association of lower resting energy expenditure with lower amounts of VLF spectral power may occur in individuals with predilections for obese phenotypes.

  2. Pulse pressure and heart rate in patients with metabolic syndrome across Europe: insights from the GOOD survey.

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    Perlini, S; Naditch-Brule, L; Farsang, C; Zidek, W; Kjeldsen, S E

    2013-07-01

    The Global Cardiometabolic Risk Profile in Patients with hypertension disease (GOOD) survey investigated the global cardiometabolic risk profile in 3464 adult outpatients with hypertension across 289 sites in 12 European countries. The pulse pressure and heart rate profile of the survey population was evaluated according to the presence or absence of metabolic syndrome and/or type 2 diabetes mellitus. History and treatment of hypertension were not counted as criteria for metabolic syndrome as they applied to all patients. Out of the 3370 recruited patients, 1033 had metabolic syndrome and 1177 had neither metabolic syndrome nor diabetes. When compared with patients with no metabolic syndrome or diabetes, patients with metabolic syndrome had higher pulse pressure (59±14 vs. 55±14 mm Hg) and heart rate (75.2±11.0 vs. 72.5±10.0 beats per min) (Ppulse pressure, which may at least in part reflect increased arterial stiffness and increased sympathetic tone. This may contribute, to some extent, to explaining the increased cardiovascular risk attributed to the presence of metabolic syndrome.

  3. Paradoxical dissociation between heart rate and heart rate variability following different modalities of exercise in individuals with metabolic syndrome: The RESOLVE study.

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    Boudet, Gil; Walther, Guillaume; Courteix, Daniel; Obert, Philippe; Lesourd, Bruno; Pereira, Bruno; Chapier, Robert; Vinet, Agnès; Chamoux, Alain; Naughton, Geraldine; Poirier, Paul; Dutheil, Frédéric

    2017-02-01

    Aims To analyse the effects of different modalities of exercise training on heart rate variability (HRV) in individuals with metabolic syndrome (MetS). Methods and results Eighty MetS participants (aged 50-70 years) were housed and managed in an inpatient medical centre for 21 days, including weekends. Physical activity and food intake/diet were intensively monitored. Participants were randomly assigned into three training groups, differing only by intensity of exercise: moderate-endurance-moderate-resistance ( re), high-resistance-moderate-endurance ( Re), and moderate-resistance-high-endurance ( rE). HRV was recorded before and after the intervention by 24-hour Holter electrocardiogram. Although mean 24-hour heart rate decreased more in Re than re (-11.6 ± 1.6 vs. -4.8 ± 2.1%; P = 0.010), low frequency/high frequency decreased more in re than Re (-20.4 ± 5.5% vs. + 20.4 ± 9.1%; P = 0.002) and rE (-20.4 ± 5.5% vs. -0.3 ± 11.1%; P = 0.003). Very low frequency increased more in Re than re (+121.2 ± 35.7 vs. 42.9 ± 11.3%; P = 0.004). For all HRV parameters, rE ranged between re and Re values. Low frequency/high frequency changes were linked with visceral fat loss only in re (coefficient 5.9, 95% CI 1.9-10.0; P = 0.004). By day 21, HRV parameters of MetS groups (heart rate -8.6 ± 1.0%, standard deviation of R-R intervals + 34.0 ± 6.6%, total power + 63.3 ± 11.1%; P heart rate and greater increases in very low frequency. Modality-specific relationships were observed between enhanced HRV and visceral fat loss. Clinical Trial Registration URL: http://www.clinicaltrials.gov . Unique identifier: NCT00917917.

  4. Ivabradine and metoprolol differentially affect cardiac glucose metabolism despite similar heart rate reduction in a mouse model of dyslipidemia.

    Science.gov (United States)

    Vaillant, Fanny; Lauzier, Benjamin; Ruiz, Matthieu; Shi, Yanfen; Lachance, Dominic; Rivard, Marie-Eve; Bolduc, Virginie; Thorin, Eric; Tardif, Jean-Claude; Des Rosiers, Christine

    2016-10-01

    While heart rate reduction (HRR) is a target for the management of patients with heart disease, contradictory results were reported using ivabradine, which selectively inhibits the pacemaker If current, vs. β-blockers like metoprolol. This study aimed at testing whether similar HRR with ivabradine vs. metoprolol differentially modulates cardiac energy substrate metabolism, a factor determinant for cardiac function, in a mouse model of dyslipidemia (hApoB(+/+);LDLR(-/-)). Following a longitudinal study design, we used 3- and 6-mo-old mice, untreated or treated for 3 mo with ivabradine or metoprolol. Cardiac function was evaluated in vivo and ex vivo in working hearts perfused with (13)C-labeled substrates to assess substrate fluxes through energy metabolic pathways. Compared with 3-mo-old, 6-mo-old dyslipidemic mice had similar cardiac hemodynamics in vivo but impaired (P ivabradine-treated hearts displayed significantly higher stroke volume values and glycolysis vs. their metoprolol-treated counterparts ex vivo, values for the ivabradine group being often not significantly different from 3-mo-old mice. Further analyses highlighted additional significant cardiac alterations with disease progression, namely in the total tissue level of proteins modified by O-linked N-acetylglucosamine (O-GlcNAc), whose formation is governed by glucose metabolism via the hexosamine biosynthetic pathway, which showed a similar pattern with ivabradine vs. metoprolol treatment. Collectively, our results emphasize the implication of alterations in cardiac glucose metabolism and signaling linked to disease progression in our mouse model. Despite similar HRR, ivabradine, but not metoprolol, preserved cardiac function and glucose metabolism during disease progression.

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

    Directory of Open Access Journals (Sweden)

    Freitas Júnior Ismael F

    2012-01-01

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

  6. Heart rate index

    DEFF Research Database (Denmark)

    Haedersdal, C; Pedersen, F H; Svendsen, J H

    1992-01-01

    The present study compares the variables assessed by standard exercise test with the left ventricular ejection fraction (LVEF) measured by multigated radionuclide angiocardiography (MUGA) in 77 patients early after myocardial infarction. The exercise test and MUGA were performed within two weeks...... after the myocardial infarction. A significant correlation (Spearman's correlation coefficient rs, p less than 0.05) was found between LVEF at rest and the following variables assessed at exercise test: 1) the heart rate at rest, 2) rise in heart rate, 3) ratio between maximal heart rate and heart rate...... at rest, 4) rise in systolic blood pressure, 5) rate pressure product at rest, 6) rise in rate pressure product, 7) ratio (rHR) between maximal rate pressure product and rate pressure product at rest, 8) total exercise time. The heart rate was corrected for effects caused by age (heart index (HR...

  7. Effect of voluntary hypocapnic hyperventilation or moderate hypoxia on metabolic and heart rate responses during high-intensity intermittent exercise.

    Science.gov (United States)

    Dobashi, Kohei; Fujii, Naoto; Watanabe, Kazuhito; Tsuji, Bun; Sasaki, Yosuke; Fujimoto, Tomomi; Tanigawa, Satoru; Nishiyasu, Takeshi

    2017-08-01

    To investigate the effect of voluntary hypocapnic hyperventilation or moderate hypoxia on metabolic and heart rate responses during high-intensity intermittent exercise. Ten males performed three 30-s bouts of high-intensity cycling [Ex1 and Ex2: constant-workload at 80% of the power output in the Wingate anaerobic test (WAnT), Ex3: WAnT] interspaced with 4-min recovery periods under normoxic (Control), hypocapnic or hypoxic (2500 m) conditions. Hypocapnia was developed through voluntary hyperventilation for 20 min prior to Ex1 and during each recovery period. End-tidal CO2 pressure was lower before each exercise in the hypocapnia than control trials. Oxygen uptake ([Formula: see text]) was lower in the hypocapnia than control trials (822 ± 235 vs. 1645 ± 245 mL min(-1); mean ± SD) during Ex1, but not Ex2 or Ex3, without a between-trial difference in the power output during the exercises. Heart rates (HRs) during Ex1 (127 ± 8 vs. 142 ± 10 beats min(-1)) and subsequent post-exercise recovery periods were lower in the hypocapnia than control trials, without differences during or after Ex2, except at 4 min into the second recovery period. [Formula: see text] did not differ between the control and hypoxia trials throughout. These results suggest that during three 30-s bouts of high-intensity intermittent cycling, (1) hypocapnia reduces the aerobic metabolic rate with a compensatory increase in the anaerobic metabolic rate during the first but not subsequent exercises; (2) HRs during the exercise and post-exercise recovery periods are lowered by hypocapnia, but this effect is diminished with repeated exercise bouts, and (3) moderate hypoxia (2500 m) does not affect the metabolic response during exercise.

  8. Tachycardia | Fast Heart Rate

    Science.gov (United States)

    ... SA) node --- the heart's natural pacemaker - sends out electrical signals faster than usual. The heart rate is fast, but the heart beats properly. Causes of sinus tachycardia A rapid heartbeat may be your body's response to common conditions such as: Fever Anxiety ...

  9. Heart Rate Monitors

    Science.gov (United States)

    1990-01-01

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

  10. Environment and feeding change the ability of heart rate to predict metabolism in resting Steller sea lions (Eumetopias jubatus).

    Science.gov (United States)

    Young, Beth L; Rosen, David A S; Haulena, Martin; Hindle, Allyson G; Trites, Andrew W

    2011-01-01

    The ability to use heart rate (fh) to predict oxygen consumption rates ([Formula: see text]) in Steller sea lions and other pinnipeds has been investigated in fasting animals. However, it is unknown whether established fh:[Formula: see text] relationships hold under more complex physiological situations, such as when animals are feeding or digesting. We assessed whether fh could accurately predict [Formula: see text] in trained Steller sea lions while fasting and after being fed. Using linear mixed-effects models, we derived unique equations to describe the fh:[Formula: see text] relationship for fasted sea lions resting on land and in water. Feeding did not significantly change the fh:[Formula: see text] relationship on land. However, Steller sea lions in water displayed a different fh:[Formula: see text] relationship after consuming a 4-kg meal compared with the fasting condition. Incorporating comparable published fh:[Formula: see text] data from Steller sea lions showed a distinct effect of feeding after a 6-kg meal. Ultimately, our study illustrated that both feeding and physical environment are statistically relevant when deriving [Formula: see text] from telemetered fh, but that only environment affects the practical ability to predict metabolism from fh. Updating current bioenergetic models with data gathered using these predictive fh:[Formula: see text] equations will yield more accurate estimates of metabolic rates of free-ranging Steller sea lions under a variety of physiological, behavioral, and environmental states.

  11. Metabolic rates of ATP transfer through creatine kinase (CK Flux) predict clinical heart failure events and death.

    Science.gov (United States)

    Bottomley, Paul A; Panjrath, Gurusher S; Lai, Shenghan; Hirsch, Glenn A; Wu, Katherine; Najjar, Samer S; Steinberg, Angela; Gerstenblith, Gary; Weiss, Robert G

    2013-12-11

    Morbidity and mortality from heart failure (HF) are high, and current risk stratification approaches for predicting HF progression are imperfect. Adenosine triphosphate (ATP) is required for normal cardiac contraction, and abnormalities in creatine kinase (CK) energy metabolism, the primary myocardial energy reserve reaction, have been observed in experimental and clinical HF. However, the prognostic value of abnormalities in ATP production rates through CK in human HF has not been investigated. Fifty-eight HF patients with nonischemic cardiomyopathy underwent ³¹P magnetic resonance spectroscopy (MRS) to quantify cardiac high-energy phosphates and the rate of ATP synthesis through CK (CK flux) and were prospectively followed for a median of 4.7 years. Multiple-event analysis (MEA) was performed for HF-related events including all-cause and cardiac death, HF hospitalization, cardiac transplantation, and ventricular-assist device placement. Among baseline demographic, clinical, and metabolic parameters, MEA identified four independent predictors of HF events: New York Heart Association (NYHA) class, left ventricular ejection fraction (LVEF), African-American race, and CK flux. Reduced myocardial CK flux was a significant predictor of HF outcomes, even after correction for NYHA class, LVEF, and race. For each increase in CK flux of 1 μmol g⁻¹ s⁻¹, risk of HF-related composite outcomes decreased by 32 to 39%. These findings suggest that reduced CK flux may be a potential HF treatment target. Newer imaging strategies, including noninvasive ³¹P MRS that detect altered ATP kinetics, could thus complement risk stratification in HF and add value in conditions involving other tissues with high energy demands, including skeletal muscle and brain.

  12. Heart rate turbulence.

    Science.gov (United States)

    Cygankiewicz, Iwona

    2013-01-01

    Heart rate turbulence (HRT) is a baroreflex-mediated biphasic reaction of heart rate in response to premature ventricular beats. Heart rate turbulence is quantified by: turbulence onset (TO) reflecting the initial acceleration of heart rate following premature beat and turbulence slope (TS) describing subsequent deceleration of heart rate. Abnormal HRT identifies patients with autonomic dysfunction or impaired baroreflex sensitivity due to variety of disorders, but also may reflect changes in autonomic nervous system induced by different therapeutic modalities such as drugs, revascularization, or cardiac resynchronization therapy. More importantly, impaired HRT has been shown to identify patients at high risk of all-cause mortality and sudden death, particularly in postinfarction and congestive heart failure patients. It should be emphasized that abnormal HRT has a well-established role in stratification of postinfarction and heart failure patients with relatively preserved left ventricular ejection fraction. The ongoing clinical trials will document whether HRT can be used to guide implantation of cardioverter-defibrillators in this subset of patients, not covered yet by ICD guidelines. This review focuses on the current state-of-the-art knowledge regarding clinical significance of HRT in detection of autonomic dysfunction and regarding the prognostic significance of this parameter in predicting all-cause mortality and sudden death. © 2013.

  13. Target Heart Rates

    Science.gov (United States)

    ... morning after you’ve had a good night’s sleep and before you get out of bed. According to the National Institute of Health, the average resting heart rate: for children 10 years and older, and adults ( ...

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

    Science.gov (United States)

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

    2010-10-01

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

  15. Physical activity, heart rate, metabolic profile, and estradiol in premenopausal women

    DEFF Research Database (Denmark)

    Emaus, Aina; Veierød, Marit B; Furberg, Anne-Sofie;

    2008-01-01

    syndrome (zMS); total cholesterol-high-density lipoprotein-cholesterol (HDL-C) ratio, insulin resistance, total fat tissue, BP, and triglycerides] was defined. Linear regression and linear mixed models were used, and confounding factors were tested. RESULTS: Physically active women had lower fat percentage...... were also found for fat tissue, total cholesterol-HDL-C ratio, insulin resistance, and triglycerides. A dose-response relationship was observed among the three levels of LPA and HR and zMS (Ptrend = 0.03 for LPA; Ptrend = 0.004 for HR). Women in the highest tertile of the clustered metabolic risk score......PURPOSE: To study whether physical inactive women with a tendency to develop metabolic syndrome have high levels of 17beta-estradiol (E2) of importance for breast cancer risk. METHODS: Two hundred and four healthy women of reproductive age were assessed for self-reported leisure-time physical...

  16. All about Heart Rate (Pulse)

    Science.gov (United States)

    ... get a picture of your health. Learn more: Blood Pressure Vs. Heart Rate Target Heart Rate Arrhythmias (abnormal heart rhythms) This ... Healthy 6 What are the Symptoms of High Blood Pressure? 7 All About Heart Rate (Pulse) 8 Warning Signs of a Heart Attack ...

  17. Locomotor, Heart-Rate, and Metabolic Power Characteristics of Youth Women's Field Hockey: Female Athletes in Motion (FAiM) Study

    Science.gov (United States)

    Vescovi, Jason D.

    2016-01-01

    Purpose: The purpose of this study was to quantify the locomotor, heart-rate, and metabolic power characteristics of high-level youth female field hockey matches. Method: Players from the U21 and U17 Canadian women's national teams were monitored during a 4-match test series using Global Positioning System technology. Position (forward,…

  18. Modelling heart rate kinetics.

    Science.gov (United States)

    Zakynthinaki, Maria S

    2015-01-01

    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).

  19. Modelling heart rate kinetics.

    Directory of Open Access Journals (Sweden)

    Maria S Zakynthinaki

    Full Text Available 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.

  20. Modelling Heart Rate Kinetics

    Science.gov (United States)

    Zakynthinaki, Maria S.

    2015-01-01

    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

  1. Cardiac Autonomic Modulation and the Kinetics of Heart Rate Responses in the On- and Off-Transient during Exercise in Women with Metabolic Syndrome

    Directory of Open Access Journals (Sweden)

    Lucas R. B. E. Silva

    2017-07-01

    Full Text Available Objective: To test whether women with metabolic syndrome (MS have impairments in the on- and off-transients during an incremental test and to study whether any of the MS components are independently associated with the observed responses.Research Design and Methods: Thirty-six women aged 35–55 years were divided into a group with MS (MSG, n = 19 and a control group (CG, n = 17. R-R intervals (RRi and heart rate variability (HRV were calculated on a beat-to-beat basis and the heart rate (HR at the on- and off-transient were analyzed during an incremental cardiopulmonary exercise test (CPET.Results: MSG showed lower aerobic capacity and lower parasympathetic cardiac modulation at rest compared with CG. HR values in on-transient phase were significantly lower in MSG compared with CG. The exponential amplitudes “amp” and the parameters “τ” [speed of heart rate recovery (HRR] were lower in MSG. MSG exhibited higher HR values in comparison to CG during the off-transient indicating a slower HRR. In MSG, there was an inverse and significant correlation between fasting plasma vs. ΔF and glucose vs. exponential “τ” of HRR dynamics.Conclusion: MS is associated with poor heart rate kinetics. The altered HR kinetics seems to be related to alterations in cardiac parasympathetic modulation, and glucose metabolism seems to be the major determinant.

  2. Heart rate variability in isolated rabbit hearts.

    Science.gov (United States)

    Frey, B; Heger, G; Mayer, C; Kiegler, B; Stöhr, H; Steurer, G

    1996-11-01

    The presence of heart rate variability (HRV) in patients with cardiac denervation after heart transplantation raised our interest in HRV of isolated, denervated hearts. Hearts from seven adult white ELCO rabbits were transferred to a perfusion apparatus. All hearts were perfused in the working mode and in the Langendorff mode for 20 minutes each. HRV was analyzed in the frequency domain. A computer simulated test ECG at a constant rate of 2 Hz was used for error estimation of the system. In the isolated, denervated heart, HRV was of random, broadband fluctuations, different from the well-characterized oscillations at specific frequencies in intact animals. Mean NN was 423 +/- 51 ms in the Langendorff mode, 406 +/- 33 ms in the working heart mode, and 500 ms in the test ECG. Total power was 663 +/- 207 ms2, 817 +/- 318 ms2, and 3.7 ms2, respectively. There was no significant difference in any measure of HRV between Langendorff and working heart modes. The data provide evidence for the presence of HRV in isolated, denervated rabbit hearts. Left atrial and ventricular filling, i.e., the working heart mode, did not alter HRV, indicating that left atrial or ventricular stretch did not influence the sinus nodal discharge rate.

  3. Reduced Heart Rate Volatility

    Science.gov (United States)

    Grogan, Eric L.; Morris, John A.; Norris, Patrick R.; France, Daniel J.; Ozdas, Asli; Stiles, Renée A.; Harris, Paul A.; Dawant, Benoit M.; Speroff, Theodore

    2004-01-01

    Objective: To determine if using dense data capture to measure heart rate volatility (standard deviation) measured in 5-minute intervals predicts death. Background: Fundamental approaches to assessing vital signs in the critically ill have changed little since the early 1900s. Our prior work in this area has demonstrated the utility of densely sampled data and, in particular, heart rate volatility over the entire patient stay, for predicting death and prolonged ventilation. Methods: Approximately 120 million heart rate data points were prospectively collected and archived from 1316 trauma ICU patients over 30 months. Data were sampled every 1 to 4 seconds, stored in a relational database, linked to outcome data, and de-identified. HR standard deviation was continuously computed over 5-minute intervals (CVRD, cardiac volatility–related dysfunction). Logistic regression models incorporating age and injury severity score were developed on a test set of patients (N = 923), and prospectively analyzed in a distinct validation set (N = 393) for the first 24 hours of ICU data. Results: Distribution of CVRD varied by survival in the test set. Prospective evaluation of the model in the validation set gave an area in the receiver operating curve of 0.81 with a sensitivity and specificity of 70.1 and 80.0, respectively. CVRD predict death as early as 24 hours in the validation set. Conclusions: CVRD identifies a subgroup of patients with a high probability of dying. Death is predicted within first 24 hours of stay. We hypothesize CVRD is a surrogate for autonomic nervous system dysfunction. PMID:15319726

  4. Effects of Impaired Glucose Metabolism on Heart Rate Variability and Blood Pessure Variability in Essential Hpertensive Patients

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    To investigate the effects of impaired glucose metabolism (IGM) on cardiovascular autonomic nervous systems in essential hypertensive (EH) patients by comparing heart rate variability (HRV) and blood pressure variability (BPV) in EH patients with or without type 2 diabetes mellitus (T2DM). Simultaneous 24-h recordings of ambulatory ECG and blood pressure monitoring were performed in 36 male old patients with simple EH and 33 male old patients with EH combined with T2DM. HRV analysis included time domain parameters such as SDNN, SDANN, SDNNi, rMSSD and pNN50, and total spectral power (TP) of HRV, which mainly consists of VLF, LF and HF component along with LF/HF ratio, was also obtained. The value of ambulatory blood pressure was represented as the mean blood pressure (mean systolic/mSBP, diastolic/mDBP and pulse pressure/mPP)during different periods (24 h/24 h, day time/d and night time/n). Standard deviation (SD) as well as coefficient of variance (CV) of blood pressure during each above-mentioned period were obtained to reflect the long-term BPV. Our result showed that SDNN, SDNNi, SDANN, rMSSD, PNN50, TP and HF of HRV in cases of EH with T2DM were all significantly lower than those in simple EH subjects (P<0.05). No significant differences in VLF or LF was found between the two groups (P>0.05), while LF/HF ratio was significantly higher in EH with T2DM patients than in simple EH subjects (P<0.01).Moreover, dmSBP, 24 h-mPP and dmPP were all significantly higher in EH with T2DM patients than in simple EH subjects (P<0.05), while nmSBP, 24 h-mSBP, 24 h-mDBP, dmDBP, nmDBP or nmPP showed no significant difference between this two groups of patients (P>0.05). And dSBPSD,dSBPCV and 24 h-SBPSD were all significantly higher in EH with T2DM patients than in simple EH subjects (P<0.05), while the other BPV indexes showed no significant difference between this two groups (P>0.05). It is concluded that the cardiovascular autonomic nervous systems in EH patients

  5. Impaired systolic blood pressure recovery and heart rate recovery after graded exercise in patients with metabolic syndrome.

    Science.gov (United States)

    Alihanoglu, Yusuf I; Yildiz, Bekir S; Kilic, I Dogu; Uludag, Burcu; Demirci, Emre E; Zungur, Mustafa; Evrengul, Harun; Kaftan, Asuman H

    2015-01-01

    The aim of this study was to evaluate and compare systolic blood pressure recovery and heart rate recovery (HRR) values obtained at various time intervals after maximal graded exercise treadmill testing between patients with metabolic syndrome (MS) and the controls without MS. To our knowledge, this is the first study indicating systolic blood pressure recovery (SBPR) impairment and its relations to HRR and other variables in this group of patients. The study population included 110 patients with MS (67 men, 43 women; mean age: 46 ± 9 years) and 110 control subjects who did not meet the criteria for MS (58 men, 52 women; mean age: 44 ± 10 years). All patients were selected from nonobese, apparently healthy sedentary individuals who had the ability to perform maximum exercise testing. SBPR was assessed by calculating the ratio of systolic blood pressure (SBP) obtained in the third minute of the recovery period to either the peak-exercise SBP or the SBP in the first minute of the recovery period after graded exercise testing. HRR values were calculated by subtracting the HR at the first, second, third, fourth, and fifth minutes of the recovery period from the HR reached at peak exercise. There was no significant difference found between the 2 groups with respect to age and sex distribution. As expected, patients with MS had higher waist circumference, fasting plasma glucose and serum triglyceride, and lower high-density lipoprotein cholesterol compared with control subjects. All HRR values calculated in the first, second, third, fourth, and fifth minutes were significantly detected lower in the MS group compared with the control group (HRR 1st: 32 ± 10 vs 36 ± 11; P = 0.009; HRR 2nd: 47 ± 10 vs 51 ± 11; P = 0.02; HRR 3rd: 53 ± 11 vs 58 ± 12; P = 0.001; HRR 4th: 57 ± 11 vs 64 ± 12; P 1 in patients with MS (1.01 ± 0.2 vs 0.91 ± 0.1 and 1.01 ± 0.1 vs 0.94 ± 0.1) and these were statistically significant compared with the control group (P exercise

  6. Effects of p-Synephrine alone and in Combination with Selected Bioflavonoids on Resting Metabolism, Blood Pressure, Heart Rate and Self-Reported Mood Changes

    Directory of Open Access Journals (Sweden)

    Sidney J. Stohs, Harry G Preuss, Samuel C. Keith, Patti L. Keith, Howard Miller, Gilbert R. Kaats

    2011-01-01

    Full Text Available Bitter orange (Citrus aurantium extract is widely used in dietary supplements for weight management and sports performance. Its primary protoalkaloid is p-synephrine. Most studies involving bitter orange extract and p-synephrine have used products with multiple ingredients. The current study assessed the thermogenic effects of p-synephrine alone and in conjunction with the flavonoids naringin and hesperidin in a double-blinded, randomized, placebo-controlled protocol with 10 subjects per treatment group. Resting metabolic rates (RMR, blood pressure, heart rates and a self-reported rating scale were determined at baseline and 75 min after oral ingestion of the test products in V-8 juice. A decrease of 30 kcal occurred in the placebo control relative to baseline. The group receiving p-synephrine (50 mg alone exhibited a 65 kcal increase in RMR as compared to the placebo group. The consumption of 600 mg naringin with 50 mg p-synephrine resulted in a 129 kcal increase in RMR relative to the placebo group. In the group receiving 100 mg hesperidin in addition to the 50 mg p-synephrine plus 600 mg naringin, the RMR increased by 183 kcal, an increase that was statistically significant with respect to the placebo control (p<0.02. However, consuming 1000 mg hesperidin with 50 mg p-synephrine plus 600 mg naringin resulted in a RMR that was only 79 kcal greater than the placebo group. None of the treatment groups exhibited changes in heart rate or blood pressure relative to the control group, nor there were no differences in self-reported ratings of 10 symptoms between the treatment groups and the control group. This unusual finding of a thermogenic combination of ingredients that elevated metabolic rates without corresponding elevations in blood pressure and heart-rates warrants longer term studies to assess its value as a weight control agent.

  7. Heart rates during competitive orienteering.

    OpenAIRE

    Bird, S R; Bailey, R.; Lewis, J.

    1993-01-01

    This study investigated the heart rate profiles of 16 experienced, competitive orienteers (aged 15-62 years) during three competitive events. Each competitor was assessed over three different types of course which were classified as: fast run (FR), slow run (SR) and highly physical (HP). The results showed that all subjects recorded heart rates that were between 140 and 180 beats min-1 for the majority of each event (irrespective of age or course type). The heart rate data indicated that the ...

  8. Heart rate variability and heart rate recovery as prognostic factors

    OpenAIRE

    GRAD, COSMIN

    2015-01-01

    Background and aim Heart rate (HR) can appear static and regular at rest, during exercise or recovery after exercise. However, HR is constantly adjusted due to factors such as breathing, blood pressure control, thermoregulation and the renin-angiotensin system, leading to a more dynamic response that can be quantified using HRV (heart rate variability). HRV is defined as the deviation in time between successive normal heart beat and is a noninvasive method to measure the total variation in a ...

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

    Science.gov (United States)

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

    2015-01-20

    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.

  10. Effects of diet composition on the metabolic and heart rate responses to cold water exposure in men.

    Science.gov (United States)

    Ashkar, E; Marsiglia, J C; Berreta, J A; Garcia, S A; Rodríguez, R R; Estol, C J

    1985-01-01

    The reaction to immersion in cold water (22 degrees C) was studied in ten healthy male volunteers successively receiving balanced (C), hypercarbohydrate (HC), hyperprotein (HP), and hyperlipid (HL) normocaloric diets with a three week equilibration period on each diet. Oxygen consumption (ml min-1 m-2) increased from 149 to 224 during C, from 160 to 196 during HL, from 154 to 178 during HP, and from 166 to 187 during HL. Only the first two differences were significant. Pulmonary ventilation (ml min-1 m-2) increased from 4.08 to 6.24 during C, from 4.01 to 5.48 during HC, from 3.41 to 3.83 during HP, and from 3.77 to 5.48 during HL. The difference was statistically significant only for C. Heart rate (beats/min) decreased from 73 to 64 during C, from 74 to 61 during HC, from 73 to 60 during HP and from 72 to 64 during HL. The differences were statistically significant for all diets except HL. Oral temperature decreased in all groups (range 0.4 to 1.6 degrees C). Respiratory rate changes were not statistically significant. The calorigenic reaction to cold water immersion was demonstrable for all groups but more efficient in subjects receiving either balanced or HC diets, suggesting that HP and HL diets reduce cold adaptation.

  11. Heart rate response to breathing

    DEFF Research Database (Denmark)

    Mehlsen, J; Pagh, K; Nielsen, J S

    1987-01-01

    Heart rate responses to stepwise and periodic changes in lung volume were studied in seven young healthy males. Stepwise inspiration and expiration both resulted in an increase in heart rate followed by a rapid decrease in heart rate. The fastest heart rate was reached in 1.6 +/- 0.5 s and in 3.......6 +/- 1.4 s in response to inspiration and expiration, respectively (P less than 0.01). The slowest heart rate was reached in 4.8 +/- 1.0 s and in 7.6 +/- 1.9 s in response to inspiration and expiration, respectively (P less than 0.01). Following this biphasic change the heart rate returned to a steady...... level. The difference between the fastest and the slowest heart rates was significantly larger in response to inspiration (21.7 +/- 7.3 beats per minute) than in response to expiration (12.0 +/- 7.3 beats per minute; P less than 0.01). Periodic changes in lung volume were performed with frequencies from...

  12. Circadian rhythm of heart rate and heart rate variability

    OpenAIRE

    Massin, M; Maeyns, K.; Withofs, N.; Ravet, F.; Gerard, P.; Healy, M.

    2000-01-01

    BACKGROUND—Measurements of heart rate variability (HRV) are increasingly used as markers of cardiac autonomic activity.
AIM—To examine circadian variation in heart rate and HRV in children.
SUBJECTS—A total of 57 healthy infants and children, aged 2 months to 15 years, underwent ambulatory 24 hour Holter recording. Monitoring was also performed on five teenagers with diabetes mellitus and subclinical vagal neuropathy in order to identify the origin of the circadian variat...

  13. High intensity interval training (HIIT) improves resting blood pressure, metabolic (MET) capacity and heart rate reserve without compromising cardiac function in sedentary aging men.

    Science.gov (United States)

    Grace, Fergal; Herbert, Peter; Elliott, Adrian D; Richards, Jo; Beaumont, Alexander; Sculthorpe, Nicholas F

    2017-05-13

    This study examined a programme of pre-conditioning exercise with subsequent high intensity interval training (HIIT) on blood pressure, echocardiography, cardiac strain mechanics and maximal metabolic (MET) capacity in sedentary (SED) aging men compared with age matched masters athletes (LEX). Using a STROBE compliant observational design, 39 aging male participants (SED; n=22, aged 62.7±5.2yrs) (LEX; n=17, aged=61.1±5.4yrs) were recruited to a study that necessitated three distinct assessment phases; enrolment (Phase A), following pre-conditioning exercise in SED (Phase B), then following 6weeks of HIIT performed once every five days by both groups before reassessment (Phase C). Hemodynamic, echocardiographic and cardiac strain mechanics were obtained at rest and maximal cardiorespiratory and chronotropic responses were obtained at each measurement phase. The training intervention improved systolic, mean arterial blood pressure, rate pressure product and heart rate reserve (each P<0.05) in SED and increased MET capacity in both SED and LEX (P<0.01) which was amplified by HIIT. Echocardiography and cardiac strain measures were unremarkable apart from trivial increase to intra-ventricular septum diastole (IVSd) (P<0.05) and decrease to left ventricular internal dimension diastole (LVId) (P<0.05) in LEX following HIIT. A programme of preconditioning exercise with HIIT induces clinically relevant improvements in blood pressure, rate pressure product and encourages recovery of heart rate reserve in SED, while improving maximal MET capacity in both SED and LEX without inducing any pathological cardiovascular remodeling. These data add to the emerging repute of HIIT as a safe and promising exercise prescription to improve cardiovascular function and metabolic capacity in sedentary aging. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  14. Heart rate and metabolic responses to moderate-intensity aerobic exercise: a comparison of graded walking and ungraded jogging at a constant perceived exertion.

    Science.gov (United States)

    Kilpatrick, Marcus W; Kraemer, Robert R; Quigley, Edward J; Mears, Jennifer L; Powers, Jeremy M; Dedea, Anthony J; Ferrer, Nicholas F

    2009-03-01

    In this study, we assessed how ungraded jogging and graded walking at the same rating of perceived exertion (RPE) affect heart rate and oxygen consumption ([Vdot]O(2)). Twenty untrained participants completed a treadmill test to determine peak [Vdot]O(2) (mean = 40.3 +/- 6.3 ml . kg(-1) . min(-1)). Participants completed separate 30-min trials of moderate exercise (RPE of 13 on the Borg 6-20 scale) in random order on the treadmill: graded walking and ungraded jogging. Treadmill speed or grade was adjusted throughout the trial by the experimenter based on participant responses to maintain an RPE of 13. The jogging trial produced a significantly higher heart rate (161 +/- 18 vs. 142 +/- 24 beats . min(-1)) and [Vdot]O(2) (7.4 +/- 1.8 vs. 5.8 +/- 1.5 METs) (P jogging trial (5.2 +/- 1.0 miles . h(-1) to 5.0 +/- 0.9 miles . h(-1)) (P > 0.05), in an effort to maintain constant RPE. These findings provide evidence that similar perceptions of effort during graded walking and ungraded jogging do not produce similar cardiovascular and metabolic responses. The results indicate that, for a given prescribed perceived effort, jogging provides a greater stimulus for fitness benefits and caloric expenditure.

  15. Blood Pressure vs. Heart Rate

    Science.gov (United States)

    ... Artery Disease Venous Thromboembolism Aortic Aneurysm More Blood Pressure vs. Heart Rate (Pulse) Updated:Sep 15,2017 ... content was last reviewed October 2016. High Blood Pressure • Home • Get the Facts About HBP Introduction What ...

  16. Heart Rate Sensor for Freshwater Mussels

    Science.gov (United States)

    Just, C. L.; Vial, D. P.; Kruger, A.; Niemeier, J. J.; Lee, H. W.; Schroer, H. W.

    2014-12-01

    Researchers have long been interested the cardiac activity of mollusks. First, it is important as a basic measure of the animal's metabolism. Further, activities such as feeding and burrowing affect heart rate, as do environmental factors such as water salinity, water temperature, exposure, and predation. We have developed a small, noninvasive sensor for measuring freshwater mussel heart rate. Its working principle is as follows. An infrared (IR) light-emitting diode is placed in contact with the mussel shell. Some of the IR penetrates through the shell, reflects off internal organs, and traverses back. A photodetector detects this IR, and electronics condition the signal. The heartbeat of the animal modulates the IR, allowing one to measure the heart rate. The technique is widely-used in finger heart-rate monitors in humans. The sensors do not have to be positioned above the heart and several locations on the mussel shell work well. The sensor is small (8 mm × 10 mm) and consumes less than 1 mA, and has a simple one-wire interface that allows for easy integration into data acquisition hardware. We present heart rate measurements for the common pocketbook (lampsilis cardium) freshwater mussel.

  17. Heart rates during competitive orienteering.

    Science.gov (United States)

    Bird, S R; Bailey, R; Lewis, J

    1993-03-01

    This study investigated the heart rate profiles of 16 experienced, competitive orienteers (aged 15-62 years) during three competitive events. Each competitor was assessed over three different types of course which were classified as: fast run (FR), slow run (SR) and highly physical (HP). The results showed that all subjects recorded heart rates that were between 140 and 180 beats min-1 for the majority of each event (irrespective of age or course type). The heart rate data indicated that the activity was largely aerobic but varied in intensity, with phases of strenuous anaerobic work. The type of course was shown significantly (analysis of variance; P orienteer (FR = 160, HP = 158, SR = 150 beats min-1), with courses that required more technical skill and hence slower running producing lower mean heart rates; although the general physical demands were similar for all courses. The older orienteers (> 45 years) recorded heart rate profiles that were similar to those of the young orienteers with no correlation being found between age and mean heart rate while exercising.

  18. HCN Channels and Heart Rate

    Directory of Open Access Journals (Sweden)

    Ilaria Dentamaro

    2012-04-01

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

  19. Dimensional analysis of heart rate variability in heart transplant recipients

    Energy Technology Data Exchange (ETDEWEB)

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

    1987-01-01

    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.

  20. Potassium supplementation and heart rate

    NARCIS (Netherlands)

    Gijsbers, L.; Molenberg, Famke; Bakker, S.J.L.; Geleijnse, J.M.

    2016-01-01

    Background and aims: Increasing the intake of potassium has been shown to lower blood pressure, but whether it also affects heart rate (HR) is largely unknown. We therefore assessed the effect of potassium supplementation on HR in a meta-analysis of randomized controlled trials. Methods and resul

  1. Heart rate variability and heart rate recovery as prognostic factors.

    Science.gov (United States)

    Grad, Cosmin

    2015-01-01

    Heart rate (HR) can appear static and regular at rest, during exercise or recovery after exercise. However, HR is constantly adjusted due to factors such as breathing, blood pressure control, thermoregulation and the renin-angiotensin system, leading to a more dynamic response that can be quantified using HRV (heart rate variability). HRV is defined as the deviation in time between successive normal heart beat and is a noninvasive method to measure the total variation in a number of HR interval. HRV can serve as measure of autonomic activity of sino-atrial node. The aim of the study was to determine the influence of certain clinical and paraclinical parameters on heart rate recovery after exercise in patients with ischemic heart disease and the relation with HRV using 24 h Holter monitoring. The study included 46 patients who were submitted to cardiovascular exercise stress test and also to 24 h Holter EKG monitoring. Subjects had a mean age of 56.2±11.2 years, with a minimum of 25 and a maximum of 79 years. The study included 22 (47.8%) men and 24 (52.2%) women. Statistical analysis was performed using MedCalc software version 14.8.1. Multivariate analysis consisted of the construction of several multiple linear regression models. A p value of 0.05 was considered statistically significant. The HRV values (time domain) were all lower in the IHD compared with the group without coronary heart disease, even if the difference is not statistically significant. Also rest and maximal HR values were similar but during the test varies in the sense that those with IHD had higher values of rest and maximal HR and lower HRR, but not statistically significant. HRV is a very easy and safe method if there is an available device and it is used for evaluation of the autonomic nervous system in many cardiovascular diseases, but also in other pathologies. In uncomplicated ischemic heart disease HRV is depressed, but not significant. HRR, which is also considered an indicator of the

  2. All about Heart Rate (Pulse)

    Science.gov (United States)

    ... Cholesterol Tools & Resources Congenital Defects Children & Adults About Congenital Heart Defects The Impact of Congenital Heart Defects Understand Your Risk for Congenital Heart Defects Symptoms & ...

  3. Resting heart rate, heart rate variability and functional decline in old age

    DEFF Research Database (Denmark)

    Ogliari, Giulia; Mahinrad, Simin; Stott, David J;

    2015-01-01

    BACKGROUND: Heart rate and heart rate variability, markers of cardiac autonomic function, have been linked with cardiovascular disease. We investigated whether heart rate and heart rate variability are associated with functional status in older adults, independent of cardiovascular disease. METHODS......: We obtained data from the Prospective Study of Pravastatin in the Elderly at Risk (PROSPER). A total of 5042 participants were included in the present study, and mean followup was 3.2 years. Heart rate and heart rate variability were derived from baseline 10-second electrocardiograms. Heart rate...... heart rate and lower heart rate variability were associated with worse functional status and with higher risk of future functional decline in older adults...

  4. Diabetes and Technology for Increased Activity (DaTA Study: The effects of exercise and technology on heart rate variability and metabolic syndrome risk factors.

    Directory of Open Access Journals (Sweden)

    Melanie I Stuckey

    2013-09-01

    Full Text Available This study tested the hypothesis that an eight-week exercise intervention supported by mobile health (mHealth technology would improve metabolic syndrome (MetS risk factors and heart rate variability (HRV in a population with MetS risk factors. Participants (n=12; 3 male; aged 56.9±7.0y reported to the laboratory for assessment of MetS risk factors and fitness (VO2max at baseline (V0 and after eight-weeks (V2 of intervention. Participants received an individualized exercise prescription and a mHealth technology kit for remote monitoring of blood pressure (BP, blood glucose, physical activity and body weight via smartphone. Participants underwent 24-h ambulatory monitoring of R-R intervals following V0 and V2. Low and high frequency powers of HRV were assessed from the recording and the ratio of low-to-high frequency powers and low and high frequency power in normalized units were calculated. One-way repeated measures analysis of variance showed that waist circumference (V0: 113.1±11.0cm, V2: 108.1±14.7cm; p=0.004 and diastolic BP (V0: 81±6mmHg, V2: 76±11mmHg; p=0.04 were reduced and VO2max increased (V0: 31.3ml/kg/min, V2: 34.8ml/kg/min; p=0.02 with no changes in other MetS risk factors. Low and high frequency powers in normalized units were reduced (V0: 75.5±12.0, V2: 72.0±12.1; p=0.03 and increased (V0: 24.5±12.0, V2: 28.0±12.1; p=0.03, respectively, with no other changes in HRV. Over the intervention period, changes in systolic BP were correlated negatively with the changes in R-R interval (r=-0.600; p=0.04 and positively with the changes in heart rate (r=0.611; p=0.03, with no other associations between MetS risk factors and HRV parameters. Thus, this eight-week mHealth supported exercise intervention improved MetS risk factors and HRV parameters, but only changes in systolic BP were associated with improved autonomic function.

  5. Multifractality and heart rate variability

    Science.gov (United States)

    Sassi, Roberto; Signorini, Maria Gabriella; Cerutti, Sergio

    2009-06-01

    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.

  6. Heart rate reduction in coronary artery disease and heart failure.

    Science.gov (United States)

    Ferrari, Roberto; Fox, Kim

    2016-08-01

    Elevated heart rate is known to induce myocardial ischaemia in patients with coronary artery disease (CAD), and heart rate reduction is a recognized strategy to prevent ischaemic episodes. In addition, clinical evidence shows that slowing the heart rate reduces the symptoms of angina by improving microcirculation and coronary flow. Elevated heart rate is an established risk factor for cardiovascular events in patients with CAD and in those with chronic heart failure (HF). Accordingly, reducing heart rate improves prognosis in patients with HF, as demonstrated in SHIFT. By contrast, data from SIGNIFY indicate that heart rate is not a modifiable risk factor in patients with CAD who do not also have HF. Heart rate is also an important determinant of cardiac arrhythmias; low heart rate can be associated with atrial fibrillation, and high heart rate after exercise can be associated with sudden cardiac death. In this Review, we critically assess these clinical findings, and propose hypotheses for the variable effect of heart rate reduction in cardiovascular disease.

  7. Occupational stress and heart rate variability

    National Research Council Canada - National Science Library

    Martin Rauber; Marjan Bilban; Radovan Starc

    2015-01-01

    Brief description of the article: This article considers heart rate variability as a measurable parameter of stress reaction and present recent studies that examined the impact of occupational stress on heart rate variability...

  8. Wearable sensor for heart rate detection

    Science.gov (United States)

    Shi, Cong; Liu, Xiaohua; Kong, Lingqin; Wu, Jizhe; Liu, Ming; Dong, Liquan; Hui, Mei; Zhao, Yuejin

    2015-08-01

    In recent years heart and blood vessel diseases kill more people than everything else combined. The daily test of heart rate for the prevention and treatment of the heart head blood-vessel disease has the vital significance. In order to adapt the transformation of medical model and solve the low accuracy problem of the traditional method of heart rate measuring, we present a new method to monitor heart rate in this paper. The heart rate detection is designed for daily heart rate detection .The heart rate signal is collected by the heart rate sensor. The signal through signal processing circuits converts into sine wave and square wave in turn. And then the signal is transmitted to the computer by data collection card. Finally, we use LABVIEW and MATLAB to show the heart rate wave and calculate the heart rate. By doing contrast experiment with medical heart rate product, experimental results show that the system can realize rapidly and accurately measure the heart rate value. A measurement can be completed within 10 seconds and the error is less than 3beat/min. And the result shows that the method in this paper has a strong anti-interference ability. It can effectively suppress the movement interference. Beyond that the result is insensitive to light.

  9. [Resting heart rate and cardiovascular disease].

    Science.gov (United States)

    Brito Díaz, Buenaventura; Alemán Sánchez, José Juan; Cabrera de León, Antonio

    2014-07-07

    Heart rate reflects autonomic nervous system activity. Numerous studies have demonstrated that an increased heart rate at rest is associated with cardiovascular morbidity and mortality as an independent risk factor. It has been shown a link between cardiac autonomic balance and inflammation. Thus, an elevated heart rate produces a micro-inflammatory response and is involved in the pathogenesis of endothelial dysfunction. In turn, decrease in heart rate produces benefits in congestive heart failure, myocardial infarction, atrial fibrillation, obesity, hyperinsulinemia, insulin resistance, and atherosclerosis. Alteration of other heart rate-related parameters, such as their variability and recovery after exercise, is associated with risk of cardiovascular events. Drugs reducing the heart rate (beta-blockers, calcium antagonists and inhibitors of If channels) have the potential to reduce cardiovascular events. Although not recommended in healthy subjects, interventions for reducing heart rate constitute a reasonable therapeutic goal in certain pathologies. Copyright © 2013 Elsevier España, S.L. All rights reserved.

  10. Rhesus monkey heart rate during exercise

    Science.gov (United States)

    Delorge, J.; Thach, J. S., Jr.

    1972-01-01

    Various schedules of reinforcement and their relation to heart rates of rhesus monkeys during exercise are described. All the reinforcement schedules produced 100 per cent or higher increments in the heart rates of the monkeys during exercise. Resting heart rates were generally much lower than those previously reported, which was attributed to the lack of physical restraint of the monkeys during recording.

  11. Heart Rate, Life Expectancy and the Cardiovascular System: Therapeutic Considerations.

    Science.gov (United States)

    Boudoulas, Konstantinos Dean; Borer, Jeffrey S; Boudoulas, Harisios

    2015-01-01

    It has long been known that life span is inversely related to resting heart rate in most organisms. This association between heart rate and survival has been attributed to the metabolic rate, which is greater in smaller animals and is directly associated with heart rate. Studies have shown that heart rate is related to survival in apparently healthy individuals and in patients with different underlying cardiovascular diseases. A decrease in heart rate due to therapeutic interventions may result in an increase in survival. However, there are many factors regulating heart rate, and it is quite plausible that these may independently affect life expectancy. Nonetheless, a fast heart rate itself affects the cardiovascular system in multiple ways (it increases ventricular work, myocardial oxygen consumption, endothelial stress, aortic/arterial stiffness, decreases myocardial oxygen supply, other) which, in turn, may affect survival. In this brief review, the effects of heart rate on the heart, arterial system and survival will be discussed. © 2015 S. Karger AG, Basel.

  12. Correlation analysis between resting heart rate and metabolic syndrome in postmenopausal women%静息心率与绝经女性代谢综合征的相关性分析

    Institute of Scientific and Technical Information of China (English)

    张雅萍; 蒋建家

    2016-01-01

    目的:探讨静息心率(RHR)与绝经女性代谢综合征的相关性。方法对182例绝经后女性进行体格检查(包括腰围、身高、体重、血压、静息心率)、实验室检查(包括空腹血糖、甘油三酯、高密度脂蛋白胆固醇、尿酸),观察不同静息心率水平的血压、血糖、血脂变化,以及其相关性/分析静息心率与代谢综合征患病率的关系。结果182例研究对象中共检出112例代谢综合征,总患病率为61.54%。相关分析显示,静息心率与腰围、空腹血糖、收缩压、舒张压、甘油三酯呈正相关,与高密度脂蛋白呈负相关。高 RHR 组代谢综合征患病率高于低 RHR 组,差异有统计学意义。结论静息心率与绝经女性代谢综合征存在相关性,在临床工作中不能忽视静息心率的控制。%Objective To investigate the correlation of resting heart rate and metabolic syndrome in post-menopausal women. Methods An physical examination (including waist,height,weight,blood pressure, resting heart rate)and laboratory test (including fasting blood glucose,triglyceride,high density lipoprotein-cholesterol,uric acid)were performed for 182 postmenopausal women,then we observed the changes and corre-lation of blood pressure,blood glucose and blood lipid in different resting heart rate levels,and the relationship between resting heart rate and the incidence of metabolic syndrome was analyzed. Results A total of 1 12 pa-tients were detected out with metabolic syndrome among 182 study objects.The morbidity rate was 61.54%. Resting heart rate had positive relation to waist,fasting blood-glucose,systolic pressure,diastolic pressure, triglyceride,and had negative relation to high density lipoprotein-cholesterol.The morbidity rate of metabolic syndrome in high resting heart rate group was higher than that in low resting heart rate group,the difference was statistically significant. Conclusion There was a correlation between resting

  13. Reduced Dietary Sodium Intake Increases Heart Rate

    DEFF Research Database (Denmark)

    Graudal, Niels A; Hubeck-Graudal, Thorbjørn; Jürgens, Gesche

    2016-01-01

    Reduced dietary sodium intake (sodium reduction) increases heart rate in some studies of animals and humans. As heart rate is independently associated with the development of heart failure and increased risk of premature death a potential increase in heart rate could be a harmful side......-effect of sodium reduction. The purpose of the present meta-analysis was to investigate the effect of sodium reduction on heart rate. Relevant studies were retrieved from an updated pool of 176 randomized controlled trials (RCTs) published in the period 1973-2014. Sixty-three of the RCTs including 72 study...... populations reported data on heart rate. In a meta-analysis of these data sodium reduction increased heart rate with 1.65 beats per minute [95% CI: 1.19, 2.11], p sodium reduction...

  14. Metabolic remodeling in chronic heart failure

    Institute of Scientific and Technical Information of China (English)

    Jing WANG; Tao GUO

    2013-01-01

    Although the management of chronic heart failure (CHF) has made enormous progress over the past decades,CHF is still a tremendous medical and societal burden.Metabolic remodeling might play a crucial role in the pathophysiology of CHF.The characteristics and mechanisms of metabolic remodeling remained unclear,and the main hypothesis might include the changes in the availability of metabolic substrate and the decline of metabolic capability.In the early phases of the disease,metabolism shifts toward carbohydrate utilization from fatty acids (FAs) oxidation.Along with the progress of the disease,the increasing level of the hyperadrenergic state and insulin resistance cause the changes that shift back to a greater FA uptake and oxidation.In addition,a growing body of experimental and clinical evidence suggests that the improvement in the metabolic capability is likely to be more significant than the selection of the substrate.

  15. Periodic heart rate decelerations in premature infants

    OpenAIRE

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

    2010-01-01

    The pacemaking system of the heart is complex; a healthy heart constantly integrates and responds to extracardiac signals, resulting in highly complex heart rate patterns with a great deal of variability. In the laboratory and in some pathological or age-related states, however, dynamics can show reduced complexity that is more readily described and modeled. Reduced heart rate complexity has both clinical and dynamical significance – it may provide warning of impending illness or clues about ...

  16. Heart rate profile during exercise in patients with early repolarization.

    Science.gov (United States)

    Cay, Serkan; Cagirci, Goksel; Atak, Ramazan; Balbay, Yucel; Demir, Ahmet Duran; Aydogdu, Sinan

    2010-09-01

    Both early repolarization and altered heart rate profile are associated with sudden death. In this study, we aimed to demonstrate an association between early repolarization and heart rate profile during exercise. A total of 84 subjects were included in the study. Comparable 44 subjects with early repolarization and 40 subjects with normal electrocardiogram underwent exercise stress testing. Resting heart rate, maximum heart rate, heart rate increment and decrement were analyzed. Both groups were comparable for baseline characteristics including resting heart rate. Maximum heart rate, heart rate increment and heart rate decrement of the subjects in early repolarization group had significantly decreased maximum heart rate, heart rate increment and heart rate decrement compared to control group (all P heart rate increment (heart rate decrement (heart rate increment and heart rate decrement compared to higher levels, respectively. Subjects with early repolarization have altered heart rate profile during exercise compared to control subjects. This can be related to sudden death.

  17. Scale Invariant Properties in Heart Rate Signals

    Science.gov (United States)

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

    2006-05-01

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

  18. Metabolically healthy obesity and ischemic heart disease

    DEFF Research Database (Denmark)

    Hansen, Louise; Netterstrøm, Marie K.; Johansen, Nanna B.

    2017-01-01

    Context: Recent studies have suggested that a subgroup of obese individuals is not at increased risk of obesity-related complications. This subgroup has been referred to as metabolically healthy obese. Objective: To investigate whether obesity is a risk factor for development of ischemic heart...... disease (IHD) irrespective of metabolic health. Design: In all, 6238 men and women from the Danish prospective Inter99 study were followed during 10.6 (standard deviation = 1.7) years. Setting: General community. Participants: Participants were classified according to body mass index and four metabolic...

  19. Maternal heart rate changes during labour.

    Science.gov (United States)

    Söhnchen, N; Melzer, K; Tejada, B Martinez de; Jastrow-Meyer, N; Othenin-Girard, V; Irion, O; Boulvain, M; Kayser, B

    2011-10-01

    Labour and delivery represent a considerable effort for pregnant women. Lack of aerobic fitness may limit pushing efforts during childbirth and represents increased cardiovascular strain and risk. Increasing prevalence of sedentary behaviour and lack of aerobic fitness may reduce heart rate reserve during labour. We quantified maternal heart rate reserve (maximum heart rate minus resting heart rate) of 30 healthy pregnant women during labour and delivery and related it to habitual daily physical activity levels quantified during the third pregnancy trimester by the Pregnancy Physical Activity Questionnaire. Heart rates during labour reached values similar to those observed during moderate to heavy physical exercise. During active pushing one out of five women reached heart rates more than 90% of their heart rate reserve (188 ± 7 beats per min). Half of the women reached more than 70% of heart rate reserve (172 ± 14 beats per min). Physically inactive women used more of their heart rate reserve as physically more active women (87 ± 20% vs. 65 ± 12%, upper and lower tertile respectively, plabour is increased in physically inactive women and may potentially limit the intensity and duration of pushing efforts. Such higher cardiovascular strain in physically less active women may represent increased cardiovascular risk during labour. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  20. Heart rate reduction and longevity in mice.

    Science.gov (United States)

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

    2015-03-01

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

  1. Heart rate dependency of JT interval sections.

    Science.gov (United States)

    Hnatkova, Katerina; Johannesen, Lars; Vicente, Jose; Malik, Marek

    2017-08-09

    Little experience exists with the heart rate correction of J-Tpeak and Tpeak-Tend intervals. In a population of 176 female and 176 male healthy subjects aged 32.3±9.8 and 33.1±8.4years, respectively, curve-linear and linear relationship to heart rate was investigated for different sections of the JT interval defined by the proportions of the area under the vector magnitude of the reconstructed 3D vectorcardiographic loop. The duration of the JT sub-section between approximately just before the T peak and almost the T end was found heart rate independent. Most of the JT heart rate dependency relates to the beginning of the interval. The duration of the terminal T wave tail is only weakly heart rate dependent. The Tpeak-Tend is only minimally heart rate dependent and in studies not showing substantial heart rate changes does not need to be heart rate corrected. For any correction formula that has linear additive properties, heart rate correction of JT and JTpeak intervals is practically the same as of the QT interval. However, this does not apply to the formulas in the form of Int/RR(a) since they do not have linear additive properties. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Heart Rate Extraction from Vowel Speech Signals

    Institute of Scientific and Technical Information of China (English)

    Abdelwadood Mesleh; Dmitriy Skopin; Sergey Baglikov; Anas Quteishat

    2012-01-01

    This paper presents a novel non-contact heart rate extraction method from vowel speech signals.The proposed method is based on modeling the relationship between speech production of vowel speech signals and heart activities for humans where it is observed that the moment of heart beat causes a short increment (evolution) of vowel speech formants.The short-time Fourier transform (STFT) is used to detect the formant maximum peaks so as to accurately estimate the heart rate.Compared with traditional contact pulse oximeter,the average accuracy of the proposed non-contact heart rate extraction method exceeds 95%.The proposed non-contact heart rate extraction method is expected to play an important role in modern medical applications.

  3. Losartan improves heart rate variability and heart rate turbulence in heart failure due to ischemic cardiomyopathy.

    Science.gov (United States)

    Ozdemir, Murat; Arslan, Uğur; Türkoğlu, Sedat; Balcioğlu, Serhat; Cengel, Atiye

    2007-12-01

    Heart rate variability (HRV) and heart rate turbulence are known to be disturbed and associated with excess mortality in heart failure. The aim of this study was to investigate whether losartan, when added on top of beta-blocker and angiotensin-converting enzyme inhibitor (ACEI) therapy, could improve these indices in patients with systolic heart failure. Seventy-seven patients (mean age 60.4 +/- 8.0, 80.5% male) with ischemic cardiomyopathy (mean ejection fraction 34.5 +/- 4.4%) and New York Heart Association Class II-III heart failure symptoms, already receiving a beta-blocker and an ACEI, were randomly assigned to either open-label losartan (losartan group) or no additional drug (control group) in a 2:1 ratio and the patients were followed for 12 weeks. The HRV and heart rate turbulence indices were calculated from 24-hour Holter recordings both at the beginning and at the end of follow-up. The baseline clinical characteristics, HRV, and heart rate turbulence indices were similar in the 2 groups. At 12 weeks of follow-up, all HRV parameters except pNN50 increased (SDNN: 113.2 +/- 34.2 versus 127.8 +/- 24.1, P = .001; SDANN: 101.5 +/- 31.7 versus 115.2 +/- 22.0, P = .001; triangular index: 29.9 +/- 11.1 versus 34.2 +/- 7.9, P = .008; RMSSD: 29.1 +/- 20.2 versus 34.3 +/- 23.0, P = .009; NN50: 5015.3 +/- 5554.9 versus 6446.7 +/- 6101.1, P = .024; NN50: 5.65 +/- 6.41 versus 7.24 +/- 6.99, P = .089; SDNNi: 45.1 +/- 13.3 versus 50.3 +/- 14.5, P = .004), turbulence onset decreased (-0. 61 +/- 1.70 versus -1.24 +/- 1.31, P = .003) and turbulence slope increased (4.107 +/- 3.881 versus 5.940 +/- 4.281, P = .004) significantly in the losartan group as compared with controls. A 12-week-long losartan therapy significantly improved HRV and heart rate turbulence in patients with Class II-III heart failure and ischemic cardiomyopathy already on beta-blockers and ACEI.

  4. Heart rate variability and swimming.

    Science.gov (United States)

    Koenig, Julian; Jarczok, Marc N; Wasner, Mieke; Hillecke, Thomas K; Thayer, Julian F

    2014-10-01

    Professionals in the domain of swimming have a strong interest in implementing research methods in evaluating and improving training methods to maximize athletic performance and competitive outcome. Heart rate variability (HRV) has gained attention in research on sport and exercise to assess autonomic nervous system activity underlying physical activity and sports performance. Studies on swimming and HRV are rare. This review aims to summarize the current evidence on the application of HRV in swimming research and draws implications for future research. A systematic search of databases (PubMed via MEDLINE, PSYNDEX and Embase) according to the PRISMA statement was employed. Studies were screened for eligibility on inclusion criteria: (a) empirical investigation (HRV) in humans (non-clinical); (b) related to swimming; (c) peer-reviewed journal; and (d) English language. The search revealed 194 studies (duplicates removed), of which the abstract was screened for eligibility. Fourteen studies meeting the inclusion criteria were included in the review. Included studies broadly fell into three classes: (1) control group designs to investigate between-subject differences (i.e. swimmers vs. non-swimmers, swimmers vs. other athletes); (2) repeated measures designs on within-subject differences of interventional studies measuring HRV to address different modalities of training or recovery; and (3) other studies, on the agreement of HRV with other measures. The feasibility and possibilities of HRV within this particular field of application are well documented within the existing literature. Future studies, focusing on translational approaches that transfer current evidence in general practice (i.e. training of athletes) are needed.

  5. Mental load, heart rate and heart rate variability.

    NARCIS (Netherlands)

    Blitz, P.S.; Hoogstraten, J.; Mulder, G.

    1970-01-01

    "Several investigators have shown that diminished sinus arrhythmia can be seen as an indication of increased mental load. The present experiment deals with the influence of different levels of mental load, operationalized as the number of binary choices per minute, on the regularity of the heart

  6. Periodic heart rate decelerations in premature infants.

    Science.gov (United States)

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

    2010-04-01

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

  7. Resting heart rate estimation using PIR sensors

    Science.gov (United States)

    Kapu, Hemanth; Saraswat, Kavisha; Ozturk, Yusuf; Cetin, A. Enis

    2017-09-01

    In this paper, we describe a non-invasive and non-contact system of estimating resting heart rate (RHR) using a pyroelectric infrared (PIR) sensor. This infrared system monitors and records the chest motion of a subject using the analog output signal of the PIR sensor. The analog output signal represents the composite motion due to inhale-exhale process with magnitude much larger than the minute vibrations of heartbeat. Since the acceleration of the heart activity is much faster than breathing the second derivative of the PIR sensor signal monitoring the chest of the subject is used to estimate the resting heart rate. Experimental results indicate that this ambient sensor can measure resting heart rate with a chi-square significance level of α = 0.05 compared to an industry standard PPG sensor. This new system provides a low cost and an effective way to estimate the resting heart rate, which is an important biological marker.

  8. Heart rate and respiratory rate influence on heart rate variability repeatability: effects of the correction for the prevailing heart rate

    Directory of Open Access Journals (Sweden)

    Jakub Sławomir Gąsior

    2016-08-01

    Full Text Available Background: Since heart rate variability (HRV is associated with average heart rate (HR and respiratory rate (RespRate, alterations in these parameters may impose changes in HRV. Hence the repeatability of HRV measurements may be affected by differences in HR and RespRate. The study aimed to evaluate HRV repeatability and its association with changes in HR and RespRate.Methods: Forty healthy volunteers underwent two ECG examinations seven days apart. Standard HRV indices were calculated from 5-min ECG recordings. The ECG-derived respiration signal was estimated to assess RespRate. To investigate HR impact on HRV, HRV parameters were corrected for prevailing HR. Results: Differences in HRV parameters between the measurements were associated with the changes in HR and RespRate. However, in multiple regression analysis only HR alteration proved to be independent determinant of the HRV differences – every change in HR by 1 bpm changed HRV values by 16.5% on average. After overall removal of HR impact on HRV, coefficients of variation of the HRV parameters significantly dropped on average by 26.8% (p < 0.001, i.e. by the same extent HRV reproducibility improved. Additionally, the HRV correction for HR decreased association between RespRate and HRV. Conclusions: In stable conditions, HR but not RespRate is the most powerful factor determining HRV reproducibility and even a minimal change of HR may considerably alter HRV. However, the removal of HR impact may significantly improve HRV repeatability. The association between HRV and RespRate seems to be, at least in part, HR dependent.

  9. Heart Rate and Respiratory Rate Influence on Heart Rate Variability Repeatability: Effects of the Correction for the Prevailing Heart Rate

    Science.gov (United States)

    Gąsior, Jakub S.; Sacha, Jerzy; Jeleń, Piotr J.; Zieliński, Jakub; Przybylski, Jacek

    2016-01-01

    Background: Since heart rate variability (HRV) is associated with average heart rate (HR) and respiratory rate (RespRate), alterations in these parameters may impose changes in HRV. Hence the repeatability of HRV measurements may be affected by differences in HR and RespRate. The study aimed to evaluate HRV repeatability and its association with changes in HR and RespRate. Methods: Forty healthy volunteers underwent two ECG examinations 7 days apart. Standard HRV indices were calculated from 5-min ECG recordings. The ECG-derived respiration signal was estimated to assess RespRate. To investigate HR impact on HRV, HRV parameters were corrected for prevailing HR. Results: Differences in HRV parameters between the measurements were associated with the changes in HR and RespRate. However, in multiple regression analysis only HR alteration proved to be independent determinant of the HRV differences—every change in HR by 1 bpm changed HRV values by 16.5% on average. After overall removal of HR impact on HRV, coefficients of variation of the HRV parameters significantly dropped on average by 26.8% (p < 0.001), i.e., by the same extent HRV reproducibility improved. Additionally, the HRV correction for HR decreased association between RespRate and HRV. Conclusions: In stable conditions, HR but not RespRate is the most powerful factor determining HRV reproducibility and even a minimal change of HR may considerably alter HRV. However, the removal of HR impact may significantly improve HRV repeatability. The association between HRV and RespRate seems to be, at least in part, HR dependent. PMID:27588006

  10. Peak heart rates at extreme altitudes

    DEFF Research Database (Denmark)

    Lundby, C; Van Hall, Gerrit

    2001-01-01

    We have measured maximal heart rate during a graded maximal bicycle exercise test to exhaustion in five healthy climbers before and during an expedition to Mt. Everest. Maximal heart rates at sea level were 186 (177-204) beats/min(-1) at sea level and 170 (169-182) beats/min(-1) with acute hypoxia....... After 1, 4 and 6 weeks of acclimatization to 5400 m, maximal heart rates were 155 (135-182), 158 (144-182), and 155 (140-183) beats/min(-1), respectively. Heart rates of two of the climbers were measured during their attempt to reach the summit of Mt. Everest without the use of supplemental oxygen....... The peak heart rates at 8,750 m for the two climbers were 142 and 144 beats/min(-1), which were similar to their maximal heart rates during exhaustive bicycle exercise at 5,400 m, the values being 144 and 148 beats/min(-1), respectively. The peak heart rates at 8,750 m are in agreement with other field...

  11. How to Take Your Heart Rate

    Science.gov (United States)

    ... 140 135 Some medications may keep your heart rate from going too high. If you are taking medicine for your heart or blood pressure, check with your health care team about how hard you should exercise. www. move. va. gov Physical Activity Handouts • P09 ...

  12. Metaiodobenzylguanidine and heart rate variability in heart failure

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-10-01

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

  13. FPGA Implementation of Heart Rate Monitoring System.

    Science.gov (United States)

    Panigrahy, D; Rakshit, M; Sahu, P K

    2016-03-01

    This paper describes a field programmable gate array (FPGA) implementation of a system that calculates the heart rate from Electrocardiogram (ECG) signal. After heart rate calculation, tachycardia, bradycardia or normal heart rate can easily be detected. ECG is a diagnosis tool routinely used to access the electrical activities and muscular function of the heart. Heart rate is calculated by detecting the R peaks from the ECG signal. To provide a portable and the continuous heart rate monitoring system for patients using ECG, needs a dedicated hardware. FPGA provides easy testability, allows faster implementation and verification option for implementing a new design. We have proposed a five-stage based methodology by using basic VHDL blocks like addition, multiplication and data conversion (real to the fixed point and vice-versa). Our proposed heart rate calculation (R-peak detection) method has been validated, using 48 first channel ECG records of the MIT-BIH arrhythmia database. It shows an accuracy of 99.84%, the sensitivity of 99.94% and the positive predictive value of 99.89%. Our proposed method outperforms other well-known methods in case of pathological ECG signals and successfully implemented in FPGA.

  14. Impaired energy metabolism of the taurine‑deficient heart.

    Science.gov (United States)

    Schaffer, Stephen W; Shimada-Takaura, Kayoko; Jong, Chian Ju; Ito, Takashi; Takahashi, Kyoko

    2016-02-01

    Taurine is a β-amino acid found in high concentrations in excitable tissues, including the heart. A significant reduction in myocardial taurine content leads to the development of a unique dilated, atrophic cardiomyopathy. One of the major functions of taurine in the heart is the regulation of the respiratory chain. Hence, we tested the hypothesis that taurine deficiency-mediated defects in respiratory chain function lead to impaired energy metabolism and reduced ATP generation. We found that while the rate of glycolysis was significantly enhanced in the taurine-deficient heart, glucose oxidation was diminished. The major site of reduced glucose oxidation was pyruvate dehydrogenase, an enzyme whose activity is reduced by the increase in the NADH/NAD+ ratio and by decreased availability of pyruvate for oxidation to acetyl CoA and changes in [Mg2+]i. Also diminished in the taurine-deficient heart was the oxidation of two other precursors of acetyl CoA, endogenous fatty acids and exogenous acetate. In the taurine-deficient heart, impaired citric acid cycle activity decreased both acetate oxidation and endogenous fatty acid oxidation, but reductions in the activity of the mitochondrial transporter, carnitine palmitoyl transferase, appeared to also contribute to the reduction in fatty acid oxidation. These changes diminished the rate of ATP production, causing a decline in the phosphocreatine/ATP ratio, a sign of reduced energy status. The findings support the hypothesis that the taurine-deficient heart is energy starved primarily because of impaired respiratory chain function, an increase in the NADH/NAD+ ratio and diminished long chain fatty acid uptake by the mitochondria. The results suggest that improved energy metabolism contributes to the beneficial effect of taurine therapy in patients suffering from heart failure.

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

    OpenAIRE

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

    2002-01-01

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

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

    OpenAIRE

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

    2002-01-01

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

  17. Elevated heart rate and nondipping heart rate as potential targets for melatonin: a review.

    Science.gov (United States)

    Simko, Fedor; Baka, Tomas; Paulis, Ludovit; Reiter, Russel J

    2016-09-01

    Elevated heart rate is a risk factor for cardiovascular and all-cause mortalities in the general population and various cardiovascular pathologies. Insufficient heart rate decline during the night, that is, nondipping heart rate, also increases cardiovascular risk. Abnormal heart rate reflects an autonomic nervous system imbalance in terms of relative dominance of sympathetic tone. There are only a few prospective studies concerning the effect of heart rate reduction in coronary heart disease and heart failure. In hypertensive patients, retrospective analyses show no additional benefit of slowing down the heart rate by beta-blockade to blood pressure reduction. Melatonin, a secretory product of the pineal gland, has several attributes, which predict melatonin to be a promising candidate in the struggle against elevated heart rate and its consequences in the hypertensive population. First, melatonin production depends on the sympathetic stimulation of the pineal gland. On the other hand, melatonin inhibits the sympathetic system in several ways representing potentially the counter-regulatory mechanism to normalize excessive sympathetic drive. Second, administration of melatonin reduces heart rate in animals and humans. Third, the chronobiological action of melatonin may normalize the insufficient nocturnal decline of heart rate. Moreover, melatonin reduces the development of endothelial dysfunction and atherosclerosis, which are considered a crucial pathophysiological disorder of increased heart rate and pulsatile blood flow. The antihypertensive and antiremodeling action of melatonin along with its beneficial effects on lipid profile and insulin resistance may be of additional benefit. A clinical trial investigating melatonin actions in hypertensive patients with increased heart rate is warranted.

  18. Metabolic Modulators in Heart Disease: Past, Present, and Future.

    Science.gov (United States)

    Lopaschuk, Gary D

    2017-07-01

    Ischemic heart disease and heart failure are leading causes of mortality and morbidity worldwide. They continue to be major burden on health care systems throughout the world, despite major advances made over the past 40 years in developing new therapeutic approaches to treat these debilitating diseases. A potential therapeutic approach that has been underutilized in treating ischemic heart disease and heart failure is "metabolic modulation." Major alterations in myocardial energy substrate metabolism occur in ischemic heart disease and heart failure, and are associated with an energy deficit in the heart. A metabolic shift from mitochondrial oxidative metabolism to glycolysis, as well as an uncoupling between glycolysis and glucose oxidation, plays a crucial role in the development of cardiac inefficiency (oxygen consumed per work performed) and functional impairment in ischemic heart disease as well as in heart failure. This has led to the concept that optimizing energy substrate use with metabolic modulators can be a potentially promising approach to decrease the severity of ischemic heart disease and heart failure, primarily by improving cardiac efficiency. Two approaches for metabolic modulator therapy are to stimulate myocardial glucose oxidation and/or inhibit fatty acid oxidation. In this review, the past, present, and future of metabolic modulators as an approach to optimizing myocardial energy substrate metabolism and treating ischemic heart disease and heart failure are discussed. This includes a discussion of pharmacological interventions that target enzymes involved in fatty acid uptake, fatty acid oxidation, and glucose oxidation in the heart, as well as enzymes involved in ketone and branched chain amino acid catabolism in the heart. Copyright © 2017 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

  19. Sound and vibration: effects on infants' heart rate and heart rate variability during neonatal transport.

    Science.gov (United States)

    Karlsson, Björn-Markus; Lindkvist, Marie; Lindkvist, Markus; Karlsson, Marcus; Lundström, Ronnie; Håkansson, Stellan; Wiklund, Urban; van den Berg, Johannes

    2012-02-01

    To measure the effect of sound and whole-body vibration on infants' heart rate and heart rate variability during ground and air ambulance transport. Sixteen infants were transported by air ambulance with ground ambulance transport to and from the airports. Whole-body vibration and sound levels were recorded and heart parameters were obtained by ECG signal. Sound and whole-body vibration levels exceeded the recommended limits. Mean whole-body vibration and sound levels were 0.19 m/s(2) and 73 dBA, respectively. Higher whole-body vibration was associated with a lower heart rate (p < 0.05), and higher sound level was linked to a higher heart rate (p = 0.05). The heart rate variability was significantly higher at the end of the transport than at the beginning (p < 0.01). Poorer physiological status was associated with lower heart rate variability (p < 0.001) and a lower heart rate (p < 0.01). Infants wearing earmuffs had a lower heart rate (p < 0.05). Sound and whole-body vibration during neonatal transport exceed recommended levels for adults, and sound seem to have a more stressful effect on the infant than vibrations. Infants should wear earmuffs during neonatal transport because of the stress-reducing effect. © 2011 The Author(s)/Acta Paediatrica © 2011 Foundation Acta Paediatrica.

  20. The heart rate variability when conducting anesthesia

    Directory of Open Access Journals (Sweden)

    Khmel'nitskiy I.V.

    2016-03-01

    Full Text Available The study was performed on the base of 10 years of using different methods of analysis of heart rate variability as an indicator of direct and reverse connection of the sympatho-adrenal system in the preoperative diagnosis and anesthetic monitoring. The possibility of predicting the depth of anaesthesia was analyzed, for depending on significant amounts of external and internal conditions, the level of anesthesia changes significantly. In this regard the influence of drugs and technological means of influencing the condition of all life-supporting systems, and the autonomic nervous system in particular, before, during and after anesthesia is of great practical interest. The balance of the pharmacological protection of the vegetative balance in the surgical aggression is studied, as well as the use of heart rate variability as a non-specific method in relation to nosological forms of pathology, both under internal and external influences. A review of a number of sources confirms that heart rate is virtually the only high-speed method to present the sympatho-vagal regulation, the most accessible somatic parameter for estimation of the cardiovascular system functioning in anesthesiology. The heart rate variability serves as an indicator of functional condition of autonomous (vegetative nervous system. It is proposed to perform the continuous monitoring of the autonomic indices of the heart rhythm, which allows to register sympaho-vagal imbalance. Dynamic monitoring, timely interpretation of heart rate variability are constantly in the spotlight, but the approach and methodology of the domestic and foreign authors distinctly differ on the following points: heart rythmography as a visual method of assessing information about the dynamics of slow-wave processes, spectral analysis of the heart sinus rhythm as the best method of analysis of large and small wave activity, tests of functional diagnostics for subsequent measurement of the autonomic nervous

  1. Respiration and heart rate in exercising land crabs.

    Science.gov (United States)

    Herreid, C F; Lee, L W; Shah, G M

    1979-05-01

    Land Crabs, Cardisoma guanhumi, were fitted with respiratory masks and E.C.G. electrodes and run for 10 or 20 min on a treadmill at speeds of 150 and 300 cm/min. Aerobic metabolism increased linearly with the speed of locomotion. The recovery period was characterized by a large oxygen debt. The primary respiratory adjustment to exercise was an increased ventilation volume; only a minor increase in oxygen extraction occurred. The respiratory exchange ratio increased during exercise and during recovery, presumably correlated with a metabolic acidosis. These results are similar to data collected for exercising vertebrates and the net cost of locomotion of crabs appears similar to quadrupeds. However, the heart rate in exercising crabs changed in an unexpected way: during moderate exercise no change was noted, but during heavy exercise a bradycardia developed. The reduction in rate resulted from an increase in interbeat interval and frequent pauses in the heart beat.

  2. Monitoring nocturnal heart rate with bed sensor.

    Science.gov (United States)

    Migliorini, M; Kortelainen, J M; Pärkkä, J; Tenhunen, M; Himanen, S L; Bianchi, A M

    2014-01-01

    This article is part of the Focus Theme of Methods of Information in Medicine on "Biosignal Interpretation: Advanced Methods for Studying Cardiovascular and Respiratory Systems". The aim of this study is to assess the reliability of the estimated Nocturnal Heart Rate (HR), recorded through a bed sensor, compared with the one obtained from standard electrocardiography (ECG). Twenty-eight sleep deprived patients were recorded for one night each through matrix of piezoelectric sensors, integrated into the mattress, through polysomnography (PSG) simultaneously. The two recording methods have been compared in terms of signal quality and differences in heart beat detection. On average, coverage of 92.7% of the total sleep time was obtained for the bed sensor, testifying the good quality of the recordings. The average beat-to-beat error of the inter-beat intervals was 1.06%. These results suggest a good overall signal quality, however, considering fast heart rates (HR > 100 bpm), performances were worse: in fact, the sensitivity in the heart beat detection was 28.4% while the false positive rate was 3.8% which means that a large amount of fast beats were not detected. The accuracy of the measurements made using the bed sensor has less than 10% of failure rate especially in periods with HR lower than 70 bpm. For fast heart beats the uncertainty increases. This can be explained by the change in morphology of the bed sensor signal in correspondence of a higher HR.

  3. Heart Rate Variability Analysis in General Medicine

    Directory of Open Access Journals (Sweden)

    Yi Gang

    2003-01-01

    Full Text Available Autonomic nervous system plays an integral role in homeostasis. Autonomic modulation can frequently be altered in patients with cardiac disorders as well as in patients with other critical illnesses or injuries. Assessment of heart rate variability is based on analysis of consecutive normal R-R intervals and may provide quantitative information on the modulation of cardiac vagal and sympathetic nerve input. The hypothesis that depressed heart rate variability may occur over a broad range of illness and injury, and may inversely correlated with disease severity and outcome has been tested in various clinical settings over the last decade. This article reviews recent literature concerning the potential clinical implications and limitations of heart rate variability assessment in general medicine.

  4. Resting Heart Rate and Auditory Evoked Potential

    Directory of Open Access Journals (Sweden)

    Simone Fiuza Regaçone

    2015-01-01

    Full Text Available The objective of this study was to evaluate the association between rest heart rate (HR and the components of the auditory evoked-related potentials (ERPs at rest in women. We investigated 21 healthy female university students between 18 and 24 years old. We performed complete audiological evaluation and measurement of heart rate for 10 minutes at rest (heart rate monitor Polar RS800CX and performed ERPs analysis (discrepancy in frequency and duration. There was a moderate negative correlation of the N1 and P3a with rest HR and a strong positive correlation of the P2 and N2 components with rest HR. Larger components of the ERP are associated with higher rest HR.

  5. Effects of social stress on heart rate and heart rate variability in growing pigs

    NARCIS (Netherlands)

    de Jong, IC; Sgoifo, A; Lambooij, E; Korte, SM; Blokhuis, HJ; Koolhaas, JM

    2000-01-01

    The effects of social stress on heart rate, heart rate variability and the occurrence of cardiac arrhythmias were studied in 12 growing pigs. Social stress was induced during a good competition test with a pen mate, and subsequently during a resident-intruder test with an unacquainted pig in which t

  6. Effects of social stress on heart rate and heart rate variability in growing pigs

    NARCIS (Netherlands)

    de Jong, IC; Sgoifo, A; Lambooij, E; Korte, SM; Blokhuis, HJ; Koolhaas, JM

    2000-01-01

    The effects of social stress on heart rate, heart rate variability and the occurrence of cardiac arrhythmias were studied in 12 growing pigs. Social stress was induced during a good competition test with a pen mate, and subsequently during a resident-intruder test with an unacquainted pig in which t

  7. Effects of social stress on heart rate and heart rate variability in growing pigs

    NARCIS (Netherlands)

    de Jong, IC; Sgoifo, A; Lambooij, E; Korte, SM; Blokhuis, HJ; Koolhaas, JM

    The effects of social stress on heart rate, heart rate variability and the occurrence of cardiac arrhythmias were studied in 12 growing pigs. Social stress was induced during a good competition test with a pen mate, and subsequently during a resident-intruder test with an unacquainted pig in which

  8. Heart rate profile during exercise in patients with early repolarization

    Institute of Scientific and Technical Information of China (English)

    Serkan Cay; Goksel Cagirci; Ramazan Atak; Yucel Balbay; Ahmet Duran Demir; Sinan Aydogdu

    2010-01-01

    Background Both early repolarization and altered heart rate profile are associated with sudden death. In this study, we aimed to demonstrate an association between early repolarization and heart rate profile during exercise.Methods A total of 84 subjects were included in the study. Comparable 44 subjects with early repolarization and 40 subjects with normal electrocardiogram underwent exercise stress testing. Resting heart rate, maximum heart rate, heart rate increment and decrement were analyzed.Results Both groups were comparable for baseline characteristics including resting heart rate. Maximum heart rate, heart rate increment and heart rate decrment of the subjects in early repolarization group had significantly decreased maximum heart rate, heart rate increment and heart rate decrement compared to control group (all P<0.05). The lower heart rate increment (<106 beats/min) and heart rate decrement (<95 beats/min) were significantly associated with the presence of early repolarization. After adjustment for age and sex, the multiple-adjusted OR of the risk of presence of early repolarization was 2.98 (95% CI 1.21-7.34) (P=0.018) and 7.73 (95% CI 2.84-21.03) (P <0.001) for the lower heart rate increment and heart rate decrement compared to higher levels, respectively.Conclusions Subjects with early repolarization have altered heart rate profile during exercise compared to control subjects. This can be related to sudden death.

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

    Science.gov (United States)

    Aubret, Fabien

    2013-01-01

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

  10. Heart rates increase after hatching in two species of Natricine snakes.

    Science.gov (United States)

    Aubret, Fabien

    2013-11-29

    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.

  11. Heart rate and heart rate variability in dogs with different degrees of myxomatous mitral valve disease

    DEFF Research Database (Denmark)

    Rasmussen, Caroline Elisabeth; Falk, Bo Torkel; Zois, Nora Elisabeth;

    2011-01-01

    HEART RATE AND HEART RATE VARIABILITY IN DOGS WITH DIFFERENT DEGREES OF MYXOMATOUS MITRAL VALVE DISEASE. CE Rasmussen1, T Falk1, NE Zois1, SG Moesgaard1, HD Pedersen2, J Häggström3 and LH Olsen1. 1. Department of Basic Animal and Veterinary Sciences, Faculty of Life Sciences, University...... of Copenhagen, Frederiksberg, Denmark. 2. Novo Nordic A/S, Maaloev, Denmark. 3. Department of Clinical Sciences, Swedish University of Agricultural Science, Uppsala, Sweden. Heart rate variability (HRV) is an indirect measurement of the autonomic modulation of heart rate (HR). Reduced HRV measured from short......-time electrocardiography is seen in dogs with heart failure (HF) secondary to myxomatous mitral valve disease (MMVD). However, HRV is suggested to increase with disease severity at early stages of MMVD. The aims of this study were 1) to associate HR and HRV with severity of MMVD in Cavalier King Charles Spaniels (CKCS...

  12. Fetal Heart Rate Monitoring during Labor

    Science.gov (United States)

    ... the process of checking the condition of your baby during labor and delivery by monitoring his or her heart rate with ... health care provider may decide to deliver the baby right away. In this case, the delivery of the baby is more likely to be ...

  13. Heart rate control via vagus nerve stimulation

    NARCIS (Netherlands)

    Buschman, Hendrik P.; Storm, Corstiaan J.; Duncker, Dirk J.; Verdouw, Pieter D.; Aa, van der Hans E.; Kemp, van der Peter

    2006-01-01

    Objectives: There is ample and well-established evidence that direct electrical stimulation of the vagus nerve can change heart rate in animals and humans. Since tachyarrhythmias cannot always be controlled through medication, we sought, in this pilot study, to elucidate whether a clinical implantab

  14. Metabolic Syndrome and Short-Term and Long-Term Heart Rate Variability in Elderly Free of Clinical Cardiovascular Disease : The PROOF Study

    NARCIS (Netherlands)

    Assoumou, H. G. Ntougou; Pichot, V.; Barthelemy, J. C.; Dauphinot, V.; Celle, S.; Gosse, P.; Kossovsky, M.; Gaspoz, J. M.; Roche, F.

    2010-01-01

    Objective: Autonomic nervous system (ANS) activity decrease has been associated with a higher risk of sudden cardiovascular and cerebrovascular disease. Thus, we explored the relationship between ANS control of the cardiovascular system and metabolic syndrome. Methods: We analyzed the relationship w

  15. Influence of basic heart rate and sex on heart rate turbulence in healthy subjects.

    Science.gov (United States)

    Schwab, Jörg O; Eichner, Gerrit; Veit, Gudrun; Schmitt, Heiko; Lewalter, Thorsten; Lüderitz, Berndt

    2004-12-01

    Acceleration and deceleration of the heart rate after the occurrence of a ventricular premature complex is characterized as heart rate turbulence (HRT). Two parameters quantify heart rate turbulence: onset and slope. The physiological properties have not been clarified in a large cohort of persons yet. This study evaluated properties of HRT, and focused on the influence of basic heart rate and sex on HRT. Using a special protocol, 95 persons were studied prospectively. HRT and its physiological properties were determined in 95 persons using Holter ECGs. The authors found 24% with a turbulence onset 0% and 5% with a turbulence slope women and men (745 vs 817 ms, P linear, weighted regression model revealed that an increased heart rate before a ventricular premature complex is associated with a decreased turbulence onset (P men (P = 0.0022). On the contrary, the study detected no influence of the basic heart rate on turbulence slope in women (P = 0.0015 for the comparison between women and men). Basic heart rate and sex show an influence on HRT and should be considered when using HRT for noninvasive risk stratification.

  16. Gaussian mixture model of heart rate variability.

    Directory of Open Access Journals (Sweden)

    Tommaso Costa

    Full Text Available 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.

  17. Music determines heart rate variability of singers

    Directory of Open Access Journals (Sweden)

    Björn eVickhoff

    2013-07-01

    Full Text Available Choir singing is known to promote wellbeing. One reason for this may be that singing demands a slower than normal respiration which may in turn affect heart activity. Coupling of heart rate variability (HRV to respiration is called Respiratory sinus arrhythmia (RSA. This coupling has a subjective as well as a biologically soothing effect, and it is beneficial for cardiovascular function. RSA is seen to be more marked during slow-paced breathing and at lower respiration rates (0.1 Hz and below. In this study, we investigate how singing, which is a form of guided breathing, affects HRV and RSA. The study comprises a group of healthy 18 year olds of mixed gender. The subjects are asked to; (1 hum a single tone and breathe whenever they need to; (2 sing a hymn with free, unguided breathing; and (3 sing a slow mantra and breathe solely between phrases. Heart rate (HR is measured continuously during the study. The study design makes it possible to compare above three levels of song structure. In a separate case study, we examine five individuals performing singing tasks (1-(3. We collect data with more advanced equipment, simultaneously recording HR, respiration, skin conductance and finger temperature. We show how song structure, respiration and heart rate are connected. Unison singing of regular song structures makes the hearts of the singers accelerate and decelerate simultaneously. Implications concerning the effect on wellbeing and health are discussed as well as the question how this inner entrainment may affect perception and behavior.

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

    Science.gov (United States)

    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…

  19. [Heart rate variability. Applications in psychiatry].

    Science.gov (United States)

    Servant, D; Logier, R; Mouster, Y; Goudemand, M

    2009-10-01

    The autonomic nervous system sends messages through the sympathetic and parasympathetic nervous system. The sympathetic nervous system innervates the cardioaccelerating center of the heart, the lungs (increased ventilatory rhythm and dilatation of the bronchi) and the non-striated muscles (artery contraction). It releases adrenaline and noradrenaline. As opposed to the sympathetic nervous system, it innervates the cardiomoderator center of the heart, the lungs (slower ventilatory rhythm and contraction of the bronchi) and the non-striated muscles (artery dilatation). It uses acetylcholine (ACh) as its neurotransmitter. Sympathetic and parasympathetic divisions function antagonistically to preserve a dynamic modulation of vital functions. These systems act on the heart respectively through the stellar ganglion and the vagus nerve. The interaction of these messages towards the sinoauricular node is responsible for normal cardiac variability, which can be measured by monitoring heart rate variability (HRV). Heart rate is primarily controlled by vagal activity. Sensorial data coming from the heart are fed back to the central nervous system. HRV is an indicator of both how the central nervous system regulates the autonomic nervous system, and of how peripheral neurons feed information back to the central level. HRV measures are derived by estimating the variation among a set of temporally ordered interbeat intervals. The state of perfect symmetry, which, in medical parlance, is called respiratory sinus arrhythmia (RSA), can be described as a state of cardiac coherence. Obtaining a series of interbeat intervals requires a continuous measure of heart rate, typically electrocardiography (ECG). Commercially available software is then used to define the interbeat intervals within an ECG recording. The autonomic nervous system is highly adaptable and allows the organism to maintain its balance when experiencing strain or stress. Conversely, a lack of flexibility and a rigid

  20. Heart rate recovery and heart rate complexity following resistance exercise training and detraining in young men.

    Science.gov (United States)

    Heffernan, Kevin S; Fahs, Christopher A; Shinsako, Kevin K; Jae, Sae Young; Fernhall, Bo

    2007-11-01

    The purpose of this study was to examine heart rate recovery (HRR) and linear/nonlinear heart rate variability (HRV) before and after resistance training. Fourteen young men (25.0 +/- 1.1 yr of age) completed a crossover design consisting of a 4-wk time-control period, 6 wk of resistance training (3 days/wk), and 4 wk of detraining. Linear HRV was spectrally decomposed using an autoregressive approach. Nonlinear dynamics of heart rate complexity included sample entropy (SampEn) and Lempel-Ziv entropy (LZEn). HRR was calculated from a graded maximal exercise test as maximal heart rate attained during the test minus heart rate at 1 min after exercise (HRR). There was no change in SampEn, LZEn, or HRR after the time-control portion of the study (P > 0.05). SampEn (P change in spectral measures of HRV at any time point (P > 0.05). These findings suggest that resistance exercise training increases heart rate complexity and HRR after exercise but has no effect on spectral measures of HRV in young healthy men. These autonomic changes regress shortly after cessation of training.

  1. Heart Rate and Heart Rate Variability in Parents at Risk for Child Physical Abuse.

    Science.gov (United States)

    Crouch, Julie L; Hiraoka, Regina; McCanne, Thomas R; Reo, Gim; Wagner, Michael F; Krauss, Alison; Milner, Joel S; Skowronski, John J

    2015-12-10

    The present study examined heart rate and heart rate variability (i.e., respiratory sinus arrhythmia [RSA]) in a sample of 48 general population parents (41.7% fathers), who were either at high risk (n = 24) or low risk (n = 24) for child physical abuse. During baseline assessments of heart rate and RSA, parents sat quietly for 3 min. Afterward, parents were presented with a series of anagrams (either easy or difficult) and were instructed to solve as many anagrams as possible in 3 min. As expected, high-risk (compared with low-risk) parents evinced significantly higher resting heart rate and significantly lower resting RSA. During the anagram task, high-risk parents did not evince significant changes in heart rate or RSA relative to baseline levels. In contrast, low-risk parents evinced significant increases in heart rate and significant decreases in RSA during the anagram task. Contrary to expectations, the anagram task difficulty did not moderate the study findings. Collectively, this pattern of results is consistent with the notion that high-risk parents have chronically higher levels of physiological arousal relative to low-risk parents and exhibit less physiological flexibility in response to environmental demands. High-risk parents may benefit from interventions that include components that reduce physiological arousal and increase the capacity to regulate arousal effectively. © The Author(s) 2015.

  2. Heart rate response to hypoxic exercise

    DEFF Research Database (Denmark)

    Lundby, C; Møller, P; Kanstrup, I L

    2001-01-01

    This study examined the effects of dopamine D(2)-receptor blockade on the early decrease in maximal heart rate at high altitude (4559 m). We also attempted to clarify the time-dependent component of this reduction and the extent to which it is reversed by oxygen breathing. Twelve subjects performed...... two consecutive maximal exercise tests, without and with oxygen supplementation respectively, at sea level and after 1, 3 and 5 days at altitude. On each study day, domperidone (30 mg; n=6) or no medication (n=6) was given 1 h before the first exercise session. Compared with sea level, hypoxia...... breathing completely reversed the decrease in maximal heart rate to values not different from those at sea level. In conclusion, dopamine D(2)-receptor blockade with domperidone demonstrates that hypoxic exercise in humans activates D(2)-receptors, resulting in a decrease in circulating levels...

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

    Science.gov (United States)

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

    2002-08-01

    Physical exercise is associated with parasympathetic withdrawal and increased sympathetic activity resulting in heart rate increase. The rate of post-exercise cardiodeceleration is used as an index of cardiac vagal reactivation. Analysis of heart rate variability (HRV) and complexity can provide useful information about autonomic control of the cardiovascular system. The aim of the present study was to ascertain the association between heart rate decrease after exercise and HRV parameters. Heart rate was monitored in 17 healthy male subjects (mean age: 20 years) during the pre-exercise phase (25 min supine, 5 min standing), during exercise (8 min of the step test with an ascending frequency corresponding to 70% of individual maximal power output) and during the recovery phase (30 min supine). HRV analysis in the time and frequency domains and evaluation of a newly developed complexity measure - sample entropy - were performed on selected segments of heart rate time series. During recovery, heart rate decreased gradually but did not attain pre-exercise values within 30 min after exercise. On the other hand, HRV gradually increased, but did not regain rest values during the study period. Heart rate complexity was slightly reduced after exercise and attained rest values after 30-min recovery. The rate of cardiodeceleration did not correlate with pre-exercise HRV parameters, but positively correlated with HRV measures and sample entropy obtained from the early phases of recovery. In conclusion, the cardiodeceleration rate is independent of HRV measures during the rest period but it is related to early post-exercise recovery HRV measures, confirming a parasympathetic contribution to this phase.

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

    Directory of Open Access Journals (Sweden)

    M. Javorka

    2002-08-01

    Full Text Available Physical exercise is associated with parasympathetic withdrawal and increased sympathetic activity resulting in heart rate increase. The rate of post-exercise cardiodeceleration is used as an index of cardiac vagal reactivation. Analysis of heart rate variability (HRV and complexity can provide useful information about autonomic control of the cardiovascular system. The aim of the present study was to ascertain the association between heart rate decrease after exercise and HRV parameters. Heart rate was monitored in 17 healthy male subjects (mean age: 20 years during the pre-exercise phase (25 min supine, 5 min standing, during exercise (8 min of the step test with an ascending frequency corresponding to 70% of individual maximal power output and during the recovery phase (30 min supine. HRV analysis in the time and frequency domains and evaluation of a newly developed complexity measure - sample entropy - were performed on selected segments of heart rate time series. During recovery, heart rate decreased gradually but did not attain pre-exercise values within 30 min after exercise. On the other hand, HRV gradually increased, but did not regain rest values during the study period. Heart rate complexity was slightly reduced after exercise and attained rest values after 30-min recovery. The rate of cardiodeceleration did not correlate with pre-exercise HRV parameters, but positively correlated with HRV measures and sample entropy obtained from the early phases of recovery. In conclusion, the cardiodeceleration rate is independent of HRV measures during the rest period but it is related to early post-exercise recovery HRV measures, confirming a parasympathetic contribution to this phase.

  5. Virtual spiders raise real heart rates

    OpenAIRE

    2015-01-01

    Virtual realities (VR) give rise to feelings of presence in virtual environments and have been proven a useful medium when treating specific phobias. For validation of the usability of VR for exposure therapy it is critical to investigate the techs capacity of activating the user physiologically. An experiment was designed with the purpose of investigating if virtual spiders in a virtual environment could cause a heightening of heart rate in the participants (N = 24). The hypothesis was that ...

  6. The heart-liver metabolic axis: defective communication exacerbates disease.

    Science.gov (United States)

    Baskin, Kedryn K; Bookout, Angie L; Olson, Eric N

    2014-04-01

    The heart has been recognized as an endocrine organ for over 30 years (de Bold, 2011); however, little is known about how the heart communicates with other organs in the body, and even less is known about this process in the diseased heart. In this issue of EMBO Molecular Medicine, Magida and Leinwand (2014) introduce the concept that a primary genetic defect in the heart results in aberrant hepatic lipid metabolism, which consequently exacerbates hypertrophic cardiomyopathy (HCM). This study provides evidence in support of the hypothesis that crosstalk occurs between the heart and liver, and that this becomes disrupted in the diseased state.

  7. High-Throughput Tissue Bioenergetics Analysis Reveals Identical Metabolic Allometric Scaling for Teleost Hearts and Whole Organisms.

    Science.gov (United States)

    Jayasundara, Nishad; Kozal, Jordan S; Arnold, Mariah C; Chan, Sherine S L; Di Giulio, Richard T

    2015-01-01

    Organismal metabolic rate, a fundamental metric in biology, demonstrates an allometric scaling relationship with body size. Fractal-like vascular distribution networks of biological systems are proposed to underlie metabolic rate allometric scaling laws from individual organisms to cells, mitochondria, and enzymes. Tissue-specific metabolic scaling is notably absent from this paradigm. In the current study, metabolic scaling relationships of hearts and brains with body size were examined by improving on a high-throughput whole-organ oxygen consumption rate (OCR) analysis method in five biomedically and environmentally relevant teleost model species. Tissue-specific metabolic scaling was compared with organismal routine metabolism (RMO2), which was measured using whole organismal respirometry. Basal heart OCR and organismal RMO2 scaled identically with body mass in a species-specific fashion across all five species tested. However, organismal maximum metabolic rates (MMO2) and pharmacologically-induced maximum cardiac metabolic rates in zebrafish Danio rerio did not show a similar relationship with body mass. Brain metabolic rates did not scale with body size. The identical allometric scaling of heart and organismal metabolic rates with body size suggests that hearts, the power generator of an organism's vascular distribution network, might be crucial in determining teleost metabolic rate scaling under routine conditions. Furthermore, these findings indicate the possibility of measuring heart OCR utilizing the high-throughput approach presented here as a proxy for organismal metabolic rate-a useful metric in characterizing organismal fitness. In addition to heart and brain OCR, the current approach was also used to measure whole liver OCR, partition cardiac mitochondrial bioenergetic parameters using pharmacological agents, and estimate heart and brain glycolytic rates. This high-throughput whole-organ bioenergetic analysis method has important applications in

  8. High-Throughput Tissue Bioenergetics Analysis Reveals Identical Metabolic Allometric Scaling for Teleost Hearts and Whole Organisms.

    Directory of Open Access Journals (Sweden)

    Nishad Jayasundara

    Full Text Available Organismal metabolic rate, a fundamental metric in biology, demonstrates an allometric scaling relationship with body size. Fractal-like vascular distribution networks of biological systems are proposed to underlie metabolic rate allometric scaling laws from individual organisms to cells, mitochondria, and enzymes. Tissue-specific metabolic scaling is notably absent from this paradigm. In the current study, metabolic scaling relationships of hearts and brains with body size were examined by improving on a high-throughput whole-organ oxygen consumption rate (OCR analysis method in five biomedically and environmentally relevant teleost model species. Tissue-specific metabolic scaling was compared with organismal routine metabolism (RMO2, which was measured using whole organismal respirometry. Basal heart OCR and organismal RMO2 scaled identically with body mass in a species-specific fashion across all five species tested. However, organismal maximum metabolic rates (MMO2 and pharmacologically-induced maximum cardiac metabolic rates in zebrafish Danio rerio did not show a similar relationship with body mass. Brain metabolic rates did not scale with body size. The identical allometric scaling of heart and organismal metabolic rates with body size suggests that hearts, the power generator of an organism's vascular distribution network, might be crucial in determining teleost metabolic rate scaling under routine conditions. Furthermore, these findings indicate the possibility of measuring heart OCR utilizing the high-throughput approach presented here as a proxy for organismal metabolic rate-a useful metric in characterizing organismal fitness. In addition to heart and brain OCR, the current approach was also used to measure whole liver OCR, partition cardiac mitochondrial bioenergetic parameters using pharmacological agents, and estimate heart and brain glycolytic rates. This high-throughput whole-organ bioenergetic analysis method has important

  9. Bluetooth Heart Rate Monitors for Spaceflight

    Science.gov (United States)

    Buxton, R. E.; West, M. R.; Kalogera, K. L.; Hanson, A. M.

    2016-01-01

    Heart rate monitoring is required for crewmembers during exercise aboard the International Space Station (ISS) and will be for future exploration missions. The cardiovascular system must be sufficiently stressed throughout a mission to maintain the ability to perform nominal and contingency/emergency tasks. High quality heart rate data are required to accurately determine the intensity of exercise performed by the crewmembers and show maintenance of VO2max. The quality of the data collected on ISS is subject to multiple limitations and is insufficient to meet current requirements. PURPOSE: To evaluate the performance of commercially available Bluetooth heart rate monitors (BT HRM) and their ability to provide high quality heart rate data to monitor crew health aboard the ISS and during future exploration missions. METHODS: Nineteen subjects completed 30 data collection sessions of various intensities on the treadmill and/or cycle. Subjects wore several BT HRM technologies for each testing session. One electrode-based chest strap (CS) was worn, while one or more optical sensors (OS) were worn. Subjects were instrumented with a 12-lead ECG to compare the heart rate data from the Bluetooth sensors. Each BT HRM data set was time matched to the ECG data and a +/-5bpm threshold was applied to the difference between the 2 data sets. Percent error was calculated based on the number of data points outside the threshold and the total number of data points. RESULTS: The electrode-based chest straps performed better than the optical sensors. The best performing CS was CS1 (1.6% error), followed by CS4 (3.3% error), CS3 (6.4% error), and CS2 (9.2% error). The OS resulted in 10.4% error for OS1 and 14.9% error for OS2. CONCLUSIONS: The highest quality data came from CS1, but unfortunately it has been discontinued by the manufacturer. The optical sensors have not been ruled out for use, but more investigation is needed to determine how to obtain the best quality data. CS2 will be

  10. Bluetooth Heart Rate Monitors For Spaceflight

    Science.gov (United States)

    Buxton, R. E.; West, M. R.; Kalogera, K. L.; Hanson, A. M.

    2016-01-01

    Heart rate monitoring is required for crewmembers during exercise aboard the International Space Station (ISS) and will be for future exploration missions. The cardiovascular system must be sufficiently stressed throughout a mission to maintain the ability to perform nominal and contingency/emergency tasks. High quality heart rate data are required to accurately determine the intensity of exercise performed by the crewmembers and show maintenance of VO2max. The quality of the data collected on ISS is subject to multiple limitations and is insufficient to meet current requirements. PURPOSE: To evaluate the performance of commercially available Bluetooth heart rate monitors (BT_HRM) and their ability to provide high quality heart rate data to monitor crew health aboard the ISS and during future exploration missions. METHODS: Nineteen subjects completed 30 data collection sessions of various intensities on the treadmill and/or cycle. Subjects wore several BT_HRM technologies for each testing session. One electrode-based chest strap (CS) was worn, while one or more optical sensors (OS) were worn. Subjects were instrumented with a 12-lead ECG to compare the heart rate data from the Bluetooth sensors. Each BT_HRM data set was time matched to the ECG data and a +/-5bpm threshold was applied to the difference between the 2 data sets. Percent error was calculated based on the number of data points outside the threshold and the total number of data points. RESULTS: The electrode-based chest straps performed better than the optical sensors. The best performing CS was CS1 (1.6% error), followed by CS4 (3.3% error), CS3 (6.4% error), and CS2 (9.2% error). The OS resulted in 10.4% error for OS1 and 14.9% error for OS2. CONCLUSIONS: The highest quality data came from CS1, but unfortunately it has been discontinued by the manufacturer. The optical sensors have not been ruled out for use, but more investigation is needed to determine how to obtain the best quality data. CS2 will be

  11. Insulin Resistance: Metabolic mechanisms and consequences in the heart

    Science.gov (United States)

    Abel, E. Dale; O'Shea, Karen M.; Ramasamy, Ravichandran

    2013-01-01

    Insulin resistance is a characteristic feature of obesity and Type 2 diabetes and impacts the heart in various ways. Impaired insulin-mediated glucose uptake is a uniformly observed characteristic of the heart in these states, although changes in upstream kinase signaling are variable and dependent on the severity and duration of the associated obesity or diabetes. The understanding of the physiological and pathophysiological role of insulin resistance in the heart is evolving. To maintain its high energy demands, the heart is capable of utilizing many metabolic substrates. Although, insulin signaling may directly regulate cardiac metabolism, its main role is likely the regulation of substrate delivery from the periphery to the heart. In addition to promoting glucose uptake, insulin regulates long chain fatty acid uptake, protein synthesis, and vascular function in the normal cardiovascular system. Recent advances in understanding the role of metabolic, signaling, and inflammatory pathways in obesity have provided opportunities to better understand the pathophysiology of insulin resistance in the heart. This review will summarize our current understanding of metabolic mechanisms for and consequences of insulin resistance in the heart and discuss potential new areas for investigating novel mechanisms that contribute to insulin resistance in the heart. PMID:22895668

  12. Aerobic Fitness, Heart Rate Recovery and Heart Rate Recovery Time in Indian School Children.

    Science.gov (United States)

    Fernando, Rajesh Jeniton; Ravichandran, K; Vaz, Mario

    2015-01-01

    Data on aerobic fitness and heart rate recovery in children are limited. This study was done to evaluate the relation between them in Indian school going children. Three hundred children of 7 to 10.5 years were recruited and their aerobic fitness was predicted using modified Harvard's step test (VO₂max) and 20 meter shuttle test (VO₂peak). The heart rate was monitored for 12 minutes post modified Harvard's step test. The difference between the maximum and the 1st minute HR was noted as HRR1 and the time taken to reach the resting heart rate was also recorded. VO₂max was inversely correlated with HRR1 (r = -0.64, precovery rate per unit time was 3% greater with increasing VO₂max (HR = 1.03, 95% CI:1.01 to 1.05, p = 0.013). The heart rate parameters did not show any associat with VO₂peak This study demonstrates that there is no relation between VO₂max and HRR1 after 3 minutes of modified Harvard's step test in Indian children of 7 to 10.5 years. However, aerobic fitness is a positive predictor of heart rate recovery time in this group.

  13. BIOPHYSICAL CHARACTERISATION OF THE UNDER-APPRECIATED AND IMPORTANT RELATIONSHIP BETWEEN HEART RATE VARIABILITY AND HEART RATE

    Science.gov (United States)

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

    2014-01-01

    Heart rate variability (beat-to-beat changes in the RR interval) has attracted considerable attention over the last 30+ years (PubMed currently lists >17,000 publications). Clinically, a decrease in heart rate variability is correlated to higher morbidity and mortality in diverse conditions, from heart disease to foetal distress. It is usually attributed to fluctuation in cardiac autonomic nerve activity. We calculated heart rate variability 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 papers. We show that regardless of conditions, there is a universal exponential decay-like relationship between heart rate variability and heart rate. Using two biophysical models, we develop a theory for this, and confirm that heart rate variability is primarily dependent on heart rate 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 heart rate variability and altered morbidity and mortality is substantially attributable to the concurrent change in heart rate. This calls for re-evaluation of the findings from many papers that have not adjusted properly or at all for heart rate differences when comparing heart rate variability in multiple circumstances. PMID:25225208

  14. Frequency Structure of Heart Rate Variability

    OpenAIRE

    MUKHIN, V.

    2008-01-01

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

  15. Effect of Cardiac Rehabilitation Program on Heart Rate Recovery in Coronary Heart Disease

    Directory of Open Access Journals (Sweden)

    Leila Mahdavi Anari

    2015-12-01

    Full Text Available Background: It has been suggested that the autonomic system function and the metabolic syndrome can significantly affect patients' survival. The aim of the current study was to investigate the impact of the cardiac rehabilitation program on the autonomic system balance in patients with coronary artery disease.Methods: Patients with a previous diagnosis of coronary artery disease who were referred to the Cardiovascular Rehabilitation Center of Afshar Hospital (Yazd, Iran between March and November 2011 were enrolled. All the patients participated in rehabilitation sessions 3 times a week for 12 weeks. Heart rate recovery (HRR was measured as an indicator of the autonomic system balance. In order to calculate HRR, the maximum heart rate during the exercise test was recorded. At the end of the exercise test, the patients were asked to sit down without having a cooldown period and their heart rate was recorded again after 1 minute. The difference between these 2 measurements was considered as HRR.Results: A total of 108 patients, including 86 (79.6% men and 22 (20.4% women, completed the rehabilitation course. The mean age of the study participants was 58.25 ± 9.83 years. A statistically significant improvement was observed in HRR (p value = 0.040. Significant declines were also observed in the patients' waist circumference (p value < 0.001 and systolic and diastolic blood pressures (p value = 0.018 and 0.003, respectively. A decreasing trend was observed in the patients' body mass index, but it failed to reach statistical significance (p value = 0.063. No statistically meaningful changes were noted in fasting blood glucose (p value = 0.171, high-density lipoprotein (p value = 0.070, or triglyceride concentrations (p value = 0.149. Conclusion: The cardiac rehabilitation program may help to improve HRR and several components of the metabolic syndrome in patients with coronary heart disease.

  16. The computation of evoked heart rate and blood pressure

    NARCIS (Netherlands)

    Koers, G.; Mulder, L.J.M.; van der Veen, F.M.

    1999-01-01

    For many years psychophysiologists have been interested in stimulus related changes in heart rate and blood pressure. To represent these evoked heart rate and blood pressure patterns, heart rate and blood pressure data have to be transformed into equidistant time series. This paper presents an

  17. Heart-Rate Variability—More than Heart Beats?

    Directory of Open Access Journals (Sweden)

    Gernot Ernst

    2017-09-01

    Full Text Available Heart-rate variability (HRV is frequently introduced as mirroring imbalances within the autonomous nerve system. Many investigations are based on the paradigm that increased sympathetic tone is associated with decreased parasympathetic tone and vice versa. But HRV is probably more than an indicator for probable disturbances in the autonomous system. Some perturbations trigger not reciprocal, but parallel changes of vagal and sympathetic nerve activity. HRV has also been considered as a surrogate parameter of the complex interaction between brain and cardiovascular system. Systems biology is an inter-disciplinary field of study focusing on complex interactions within biological systems like the cardiovascular system, with the help of computational models and time series analysis, beyond others. Time series are considered surrogates of the particular system, reflecting robustness or fragility. Increased variability is usually seen as associated with a good health condition, whereas lowered variability might signify pathological changes. This might explain why lower HRV parameters were related to decreased life expectancy in several studies. Newer integrating theories have been proposed. According to them, HRV reflects as much the state of the heart as the state of the brain. The polyvagal theory suggests that the physiological state dictates the range of behavior and psychological experience. Stressful events perpetuate the rhythms of autonomic states, and subsequently, behaviors. Reduced variability will according to this theory not only be a surrogate but represent a fundamental homeostasis mechanism in a pathological state. The neurovisceral integration model proposes that cardiac vagal tone, described in HRV beyond others as HF-index, can mirror the functional balance of the neural networks implicated in emotion–cognition interactions. Both recent models represent a more holistic approach to understanding the significance of HRV.

  18. Heart rate variability, sleep and sleep disorders.

    Science.gov (United States)

    Stein, Phyllis K; Pu, Yachuan

    2012-02-01

    Heart rate (HR) is modulated by the combined effects of the sympathetic and parasympathetic nervous systems. Therefore, measurement of changes in HR over time (heart rate variability or HRV) provides information about autonomic functioning. HRV has been used to identify high risk people, understand the autonomic components of different disorders and to evaluate the effect of different interventions, etc. Since the signal required to measure HRV is already being collected on the electrocardiogram (ECG) channel of the polysomnogram (PSG), collecting data for research on HRV and sleep is straightforward, but applications have been limited. As reviewed here, HRV has been applied to understand autonomic changes during different sleep stages. It has also been applied to understand the effect of sleep-disordered breathing, periodic limb movements and insomnia both during sleep and during the daytime. HRV has been successfully used to screen people for possible referral to a Sleep Lab. It has also been used to monitor the effects of continuous positive airway pressure (CPAP). A novel HRV measure, cardiopulmonary coupling (CPC) has been proposed for sleep quality. Evidence also suggests that HRV collected during a PSG can be used in risk stratification models, at least for older adults. Caveats for accurate interpretation of HRV are also presented.

  19. HEART-RATE-VARIABILITY SPECTRA BASED ON NONEQUIDISTANT SAMPLING - THE SPECTRUM OF COUNTS AND THE INSTANTANEOUS HEART-RATE SPECTRUM

    NARCIS (Netherlands)

    VANSTEENIS, HG; TULEN, JHM; MULDER, LJM

    1994-01-01

    This paper compares two methods to estimate heart rate variability spectra i.e., the spectrum of counts and the instantaneous heart rate spectrum. Contrary to Fourier techniques based on equidistant sampling of the interbeat intervals, the spectrum of counts of the instantaneous heart rate spectrum

  20. HEART-RATE-VARIABILITY SPECTRA BASED ON NONEQUIDISTANT SAMPLING - THE SPECTRUM OF COUNTS AND THE INSTANTANEOUS HEART-RATE SPECTRUM

    NARCIS (Netherlands)

    VANSTEENIS, HG; TULEN, JHM; MULDER, LJM

    This paper compares two methods to estimate heart rate variability spectra i.e., the spectrum of counts and the instantaneous heart rate spectrum. Contrary to Fourier techniques based on equidistant sampling of the interbeat intervals, the spectrum of counts of the instantaneous heart rate spectrum

  1. High-Throughput Tissue Bioenergetics Analysis Reveals Identical Metabolic Allometric Scaling for Teleost Hearts and Whole Organisms

    OpenAIRE

    Nishad Jayasundara; Kozal, Jordan S.; Arnold, Mariah C.; Chan, Sherine S. L.; Di Giulio, Richard T.

    2015-01-01

    Organismal metabolic rate, a fundamental metric in biology, demonstrates an allometric scaling relationship with body size. Fractal-like vascular distribution networks of biological systems are proposed to underlie metabolic rate allometric scaling laws from individual organisms to cells, mitochondria, and enzymes. Tissue-specific metabolic scaling is notably absent from this paradigm. In the current study, metabolic scaling relationships of hearts and brains with body size were examined by i...

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

    LENUS (Irish Health Repository)

    Moran, D

    2014-08-23

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

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

    Science.gov (United States)

    Litscher, Gerhard; Zhang, Weibo; Huang, Tao; Wang, Lu

    2011-02-01

    Tai Chi is a famous training method in China, and jogging is a popular kind of exercise both in Austria and China. Nevertheless, there is little information concerning online monitoring of biosignals during both training activities in parallel. Within the last years innovative scientific monitoring tools for evaluating features of neurocardial fitness have been developed. The goal of this study was to demonstrate heart rate and heart rate variability analysis for the first time during Tai Chi and jogging. Continuous electrocardiographic monitoring over a period of 75 minutes was performed simultaneously in two healthy volunteers using the same type of equipment (medilog AR12 systems). Two healthy persons (both male, 49 years and 52 years, respectively), both hobby sportsmen, were monitored continuously during two resting periods before and after active sport and also during Tai Chi and jogging, respectively. Data acquisition was performed without any technical problems in both subjects. Poincaré plots of sequential R-R intervals (beat to beat variability) show two ellipses of different shape and magnitude. During resting periods blood pressure effects can be clearly seen in one subject (jogging). The same effects, however reduced, are obvious in the other volunteer during Tai Chi. The present investigations during Tai Chi and jogging highlight the potential value of heart rate and heart rate variability monitoring even under difficult conditions. The innovative kind of analysis helps to show how well the human body reacts to sport, stress and recovery.

  4. The heart rate VO2 relationship of aerobic dance: a comparison of target heart rate methods.

    Science.gov (United States)

    Scharff-Olson, M; Williford, H N; Smith, F H

    1992-12-01

    The purpose of this study was to examine the relationship between heart rate (HR) and oxygen consumption (VO2) for aerobic dance exercise. Therefore, eleven females completed 20 minutes of aerobic dance with continuous monitoring of HR and VO2. These physiological responses were analyzed with correlation/regression techniques. The results showed that for aerobic dance to produce a response in excess of 50% of VO2 max, the target HR must be approximately 80% of the age-predicted HR max or greater. In contrast, previously reported data for treadmill running shows that 50% of VO2 max is achieved at approximately 65% of age-predicted HR max in females. The maximum heart rate reserve (Karvonen) method was also found to underestimate the actual VO2 of AD. With the Karvonen method, the target heart rate must approximate 65% of maximum HR reserve in order to elicit a VO2 response which is representative of 50% of VO2 max. These data support recent research which illustrates that target heart rate prescriptions derived from treadmill testing may fail to accurately place AD participants in the recommended training zone.

  5. Antioxidants, metabolic rate and aging in Drosophila

    Science.gov (United States)

    Miquel, J.; Fleming, J.; Economos, A. C.

    1982-01-01

    The metabolic rate-of-living theory of aging was investigated by determining the effect of several life-prolonging antioxidants on the metabolic rate and life span of Drosophila. The respiration rate of groups of continuously agitated flies was determined in a Gilson respirometer. Vitamin E, 2,4-dinitrophenol, nordihydroguaiaretic acid, and thiazolidine carboxylic acid were employed as antioxidants. Results show that all of these antioxidants reduced the oxygen consumption rate and increased the mean life span, and a significant negative linear correlation was found between the mean life span and the metabolic rate. It is concluded that these findings indicate that some antioxidants may inhibit respiration rate in addition to their protective effect against free radical-induced cellular damage.

  6. Robust heart rate from fitness videos.

    Science.gov (United States)

    Wang, Wenjin; den Brinker, Albertus C; Stuijk, Sander; de Haan, Gerard

    2017-06-01

    Remote photoplethysmography (rPPG) enables contactless heart-rate monitoring using a regular video camera. This paper aims to improve the rPPG technology targeting continuous heart-rate measurement during fitness exercises. The fundamental limitation of the existing (multi-wavelength) rPPG methods is that they can suppress at most n  -  1 independent distortions by linearly combining n wavelength color channels. Their performance are highly restricted when more than n  -  1 independent distortions appear in a measurement, as typically occurs in fitness applications with vigorous body motions. To mitigate this limitation, we propose an effective yet very simple method that algorithmically extends the number of possibly suppressed distortions without using more wavelengths. Our core idea is to increase the degrees-of-freedom of noise reduction by decomposing the n wavelength camera-signals into multiple orthogonal frequency bands and extracting the pulse-signal per band-basis. This processing, namely Sub-band rPPG (SB), can suppress different distortion-frequencies using independent combinations of color channels. A challenging fitness benchmark dataset is created, including 25 videos recorded from 7 healthy adult subjects (ages from 25 to 40 yrs; six male and one female) running on a treadmill in an indoor environment. Various practical challenges are simulated in the recordings, such as different skin-tones, light sources, illumination intensities, and exercising modes. The basic form of SB is benchmarked against a state-of-the-art method (POS) on the fitness dataset. Using non-biased parameter settings, the average signal-to-noise-ratio (SNR) for POS varies in [-4.18, -2.07] dB, for SB varies in [-1.08, 4.77] dB. The ANOVA test shows that the improvement of SB over POS is statistically significant for almost all settings (p-value  increases the robustness of heart-rate measurement in challenging fitness applications, and outperforms the state

  7. Fighter pilots' heart rate, heart rate variation and performance during an instrument flight rules proficiency test.

    Science.gov (United States)

    Mansikka, Heikki; Virtanen, Kai; Harris, Don; Simola, Petteri

    2016-09-01

    Increased task demand will increase the pilot mental workload (PMWL). When PMWL is increased, mental overload may occur resulting in degraded performance. During pilots' instrument flight rules (IFR) proficiency test, PMWL is typically not measured. Therefore, little is known about workload during the proficiency test and pilots' potential to cope with higher task demands than those experienced during the test. In this study, fighter pilots' performance and PMWL was measured during a real IFR proficiency test in an F/A-18 simulator. PMWL was measured using heart rate (HR) and heart rate variation (HRV). Performance was rated using Finnish Air Force's official rating scales. Results indicated that HR and HRV differentiate varying task demands in situations where variations in performance are insignificant. It was concluded that during a proficiency test, PMWL should be measured together with the task performance measurement.

  8. [Population characteristics and impact on heart rate variability, heart rate and blood pressure of passive smoking].

    Science.gov (United States)

    Zhao, Jing; He, Fei; Hu, Da-yi; Ding, Rong-jing; Yu, Xiao-jun; Wang, Long; Zhang, Ping; Li, Xue-bin; Guo, Ji-hong; Liu, Wen-ling; Li, Cui-lan; Li, Lei; Gao, Chuan-yu; Zhao, Luo-sha; Chu, Ying-jie; Huang, Zhen-wen; Wei, Jing-han; Hua, Shao-hua; Liu, Rui-yun; Zhuang, Xiao-feng

    2013-05-01

    To investigate the basic characteristics of passive smoking population, and the impact of passive smoking on heart rate variability, heart rate and blood pressure. Eighty-six passive smokers [mean age: (52.4 ± 7.6) years] were recruited from patients and their relatives who visited cardiovascular outpatient department and excluded structural heart disease between June 2010 and June 2012, 80 normal subjects who were not exposed to smoking served as controls. Questionnaire survey, 24 hours ambulatory electrocardiogram examination and blood pressure measurement were performed in all recruited subjects. (1) Non-marriage rate [18.60% (16/86) vs. 3.75% (3/80), P professional technology industry employers [20.93% (18/86) vs. 36.25% (29/80), P restaurants (48.84%, 42/86). (2) Standard of the normal sinus RR intervals (SDNN), the normal consecutive sinus RR interval difference between the root-mean-square (rMSSD) and adjacent the difference between the RR interval>50 ms the number of share the percentage (PNN50) were significantly lower in passive smoking group than in the control group (all P 0.05). Ultra-low-frequency power (VLF), low frequency power (LF), high frequency power (HF) and LF/HF were significantly lower in passive smoking group than in the control group (all P 0.05). Marriage status, education level, profession and daily working time are independent determinants for passive smoking. Passive smoking mainly occurred in the workplace, entertainment venues and restaurants. Passive smoking is linked with reduced heart rate variability, increased 24 h average heart rate and diastolic blood pressure.

  9. U.S. Heart Failure Rates on the Rise

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_163266.html U.S. Heart Failure Rates on the Rise And heart ... Medicine, the National Institutes of Health, or the U.S. Department of Health and Human Services. More Health ...

  10. High readmission rate after heart valve surgery

    DEFF Research Database (Denmark)

    Sibilitz, K L; Berg, S K; Thygesen, Lau Caspar;

    2015-01-01

    of anxiety and depression were present in 13.6% and 13.8%, respectively (Hospital Anxiety and Depression Scale score ≥ 8). Twelve months following discharge, 483 persons (56%) were readmitted. Readmission was associated with lower self-reported health (SF-36 PCS: 46.5 vs. 43.9, and MCS 52.2 vs. 50.7). Higher...... after surgery (3.2 (1.2-8.9)) predicted mortality. CONCLUSIONS: 6-12 months after heart valve surgery the readmission rate is high and the self-reported health status is low. Readmission is associated with low self-reported health. Therefore, targeted follow-up strategies post-surgery are needed....

  11. Heart rate recovery: Short review of methodology

    Directory of Open Access Journals (Sweden)

    Đurić Biljana

    2016-01-01

    Full Text Available Determination of the heart rate recovery (HRR after the session of a physical activity, represents the valuable parameter for the investigation of autonomic balance and its dynamic in the general population, but also in the population of elite athletes. However, the methodology for its determination and analysis is still not entirely specified. It is necessary to define an adequate protocol of cardiopulmonary exercise test, by choosing an adequate ergometer (treadmill, ergo-bicycle or step bench. Organization of recovery period (active or passive, after the session of exercise is also very important, because its protocol interfered significantly with the value of HRR. Interpretation of obtained HRR values varies a lot, and researcher has freedom to choose the most adequate way, in accordance with the objectives of his study. Following paper represents a short review of determination, interpretation and analysis of HRR, followed by the latest recommendations.

  12. Selecting heart failure patients for metabolic interventions

    NARCIS (Netherlands)

    Booij, Harmen G.; Koning, Anne M.; van Goor, Harry; de Boer, Rudolf A.; Westenbrink, B. Daan

    2017-01-01

    Introduction: Heart failure (HF) has become the cardiovascular epidemic of the century and now imposes an immense burden on health care systems. While our understanding of the pathophysiology of HF has increased dramatically, the translation of knowledge into clinical practice has been

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

    OpenAIRE

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

    2014-01-01

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

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

    Science.gov (United States)

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

    2013-06-01

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

  15. Inverse Correlation between Heart Rate Variability and Heart Rate Demonstrated by Linear and Nonlinear Analysis.

    Directory of Open Access Journals (Sweden)

    Syed Zaki Hassan Kazmi

    Full Text Available The dynamical fluctuations in the rhythms of biological systems provide valuable information about the underlying functioning of these systems. During the past few decades analysis of cardiac function based on the heart rate variability (HRV; variation in R wave to R wave intervals has attracted great attention, resulting in more than 17000-publications (PubMed list. However, it is still controversial about the underling mechanisms of HRV. In this study, we performed both linear (time domain and frequency domain and nonlinear analysis of HRV data acquired from humans and animals to identify the relationship between HRV and heart rate (HR. The HRV data consists of the following groups: (a human normal sinus rhythm (n = 72; (b human congestive heart failure (n = 44; (c rabbit sinoatrial node cells (SANC; n = 67; (d conscious rat (n = 11. In both human and animal data at variant pathological conditions, both linear and nonlinear analysis techniques showed an inverse correlation between HRV and HR, supporting the concept that HRV is dependent on HR, and therefore, HRV cannot be used in an ordinary manner to analyse autonomic nerve activity of a heart.

  16. HEART RATE VARIABILITY IN ASSESSMENT OF CLINICAL STATUS, FUNCTIONAL CONDITIONS AND PROGNOSIS IN HEART FAILURE

    Directory of Open Access Journals (Sweden)

    Y. A. Vasyuk

    2006-01-01

    Full Text Available Data about heart rate variability analysis in healthy people and patients with chronic heart failure are reviewed. Prognostic value of time-domain and spectral measures is mentioned. Influence of standard therapy on heart rate variability is described.

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

    Science.gov (United States)

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

    1991-01-01

    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.

  18. Influence of heavy cigarette smoking on heart rate variability and heart rate turbulence parameters

    DEFF Research Database (Denmark)

    Cagirci, Goksel; Cay, Serkan; Karakurt, Ozlem

    2009-01-01

    BACKGROUND: Cigarette smoking increases the risk of cardiovascular events related with several mechanisms. The most suggested mechanism is increased activity of sympathetic nervous system. Heart rate variability (HRV) and heart rate turbulence (HRT) has been shown to be independent and powerful...... predictors of mortality in a specific group of cardiac patients. The goal of this study was to assess the effect of heavy cigarette smoking on cardiac autonomic function using HRV and HRT analyses. METHODS: Heavy cigarette smoking was defined as more than 20 cigarettes smoked per day. Heavy cigarette smokers......, 69 subjects and nonsmokers 74 subjects (control group) were enrolled in this study. HRV and HRT analyses [turbulence onset (TO) and turbulence slope (TS)] were assessed from 24-hour Holter recordings. RESULTS: The values of TO were significantly higher in heavy cigarette smokers than control group...

  19. Genome-wide association studies and resting heart rate

    DEFF Research Database (Denmark)

    Oskari Kilpeläinen, Tuomas

    2016-01-01

    Genome-wide association studies (GWASs) have revolutionized the search for genetic variants regulating resting heart rate. In the last 10 years, GWASs have led to the identification of at least 21 novel heart rate loci. These discoveries have provided valuable insights into the mechanisms...... and pathways that regulate heart rate and link heart rate to cardiovascular morbidity and mortality. GWASs capture majority of genetic variation in a population sample by utilizing high-throughput genotyping chips measuring genotypes for up to several millions of SNPs across the genome in thousands...... of individuals. This allows the identification of the strongest heart rate associated signals at genome-wide level. While GWASs provide robust statistical evidence of the association of a given genetic locus with heart rate, they are only the starting point for detailed follow-up studies to locate the causal...

  20. Heart rate variability and blood pressure during dynamic and static exercise at similar heart rate levels.

    Science.gov (United States)

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

    2013-01-01

    Aim was to elucidate autonomic responses to dynamic and static (isometric) exercise of the lower limbs eliciting the same moderate heart rate (HR) response. 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. 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.

  1. The relationship between resting heart rate variability and heart rate recovery.

    Science.gov (United States)

    Esco, Michael R; Olson, Michele S; Williford, Henry N; Blessing, Daniel L; Shannon, David; Grandjean, Peter

    2010-02-01

    There is limited research available regarding a possible relationship between resting heart rate variability (HRV) and post-exercise heart rate recovery (HRR). The aim of this study was to examine the relationship between resting HRV and HRR after maximal exercise. Sixty-six college age men participated in this study. HRV was measured in a supine position before and for 30 min after a maximal exercise test on a treadmill. HRV was assessed in the time (i.e., SDNN) and frequency (i.e., normalized HF power [HFnu] and normalized LF:HF ratio [LFnu:HFnu]) domains. Heart rate was recorded at maximal exercise (MHR), and at 1- (HR1) and 2- (HR2) min of the cool-down recovery period. HRR was determined from the difference between MHR and HR1 (HRR1) and the difference between MHR and HR2 (HRR2). No significant relationship was found between resting HRV and HRR1 or HRR2. However, SDNN was significantly inversely correlated to MHR (P MHR (P MHR accounted for the greatest variation in both SDNN and HFnu (P MHR, HR1 and HR2 post-maximal exercise.

  2. Heart Rate Variability Interventions for Concussion and Rehabilitation

    OpenAIRE

    Robert Lake Conder; Conder, Alanna A.

    2014-01-01

    The study of Heart Rate Variability (HRV) has emerged as an essential component of cardiovascular health, as well as a physiological mechanism by which one can increase the interactive communication between the cardiac and the neurocognitive systems (i.e., the body and the brain). It is well-established that lack of heart rate variability implies cardiopathology, morbidity, reduced quality-of-life, and precipitous mortality. On the positive, optimal heart rate variability has been associated ...

  3. Heart rate modulation by sympathetic nerves in dogs with heart failure.

    Science.gov (United States)

    Uechi, Masami; Shimizu, Akira; Mizuno, Masashi

    2002-11-01

    To clarify heart rate modulation by the sympathetic nervous system, dogs with naturally acquired and experimentally induced heart failure were examined. Heart rate and plasma catecholamine concentrations were measured in clinically healthy dogs (control dogs) and dogs with mitral regurgitation (MR) during a resting period, a standing period, a period of standing in a medical examination room (to which the dogs were unaccustomed), a running period, and a period of recovery after running. The heart rate and plasma catecholamine concentration increased in control dogs during the standing period and the medical examination room period, relative to the resting period. However, dogs with MR did not exhibit any clear increase in heart rate or catecholamine concentration under these light stress conditions. Running stress increased plasma catecholamine levels in control dogs; however, dogs with MR did not exhibit any significant changes. Thirty-two dogs with naturally acquired heart disease were classified as grades I to III on the ISACHC scale. The degree of increase in heart rate and plasma catecholamine levels in dogs with naturally acquired heart failure depended on their degree of heart failure. In conclusion, an increased heart rate and an activated sympathetic nervous system were observed, even in mild heart failure. This chronically activated sympathetic activity is expected to increase myocardial oxygen consumption, myocardial hypertrophy, and fibrosis, and to portend a poorer prognosis in heart failure.

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

    Science.gov (United States)

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

    2014-12-01

    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.

  5. Embryos in the fast lane: high-temperature heart rates of turtles decline after hatching.

    Directory of Open Access Journals (Sweden)

    Wei-Guo Du

    Full Text Available In ectotherms such as turtles, the relationship between cardiovascular function and temperature may be subject to different selective pressures in different life-history stages. Because embryos benefit by developing as rapidly as possible, and can "afford" to expend energy to do so (because they have access to the yolk for nutrition, they benefit from rapid heart (and thus, developmental rates. In contrast, hatchlings do not have a guaranteed food supply, and maximal growth rates may not enhance fitness--and so, we might expect a lower heart rate, especially at high temperatures where metabolic costs are greatest. Our data on two species of emydid turtles, Chrysemys picta, and Graptemys pseudogeographica kohnii, support these predictions. Heart rates of embryos and hatchlings were similar at low temperatures, but heart rates at higher temperatures were much greater before than after hatching.

  6. Accuracy of smartphone apps for heart rate measurement.

    Science.gov (United States)

    Coppetti, Thomas; Brauchlin, Andreas; Müggler, Simon; Attinger-Toller, Adrian; Templin, Christian; Schönrath, Felix; Hellermann, Jens; Lüscher, Thomas F; Biaggi, Patric; Wyss, Christophe A

    2017-08-01

    Background Smartphone manufacturers offer mobile health monitoring technology to their customers, including apps using the built-in camera for heart rate assessment. This study aimed to test the diagnostic accuracy of such heart rate measuring apps in clinical practice. Methods The feasibility and accuracy of measuring heart rate was tested on four commercially available apps using both iPhone 4 and iPhone 5. 'Instant Heart Rate' (IHR) and 'Heart Fitness' (HF) work with contact photoplethysmography (contact of fingertip to built-in camera), while 'Whats My Heart Rate' (WMH) and 'Cardiio Version' (CAR) work with non-contact photoplethysmography. The measurements were compared to electrocardiogram and pulse oximetry-derived heart rate. Results Heart rate measurement using app-based photoplethysmography was performed on 108 randomly selected patients. The electrocardiogram-derived heart rate correlated well with pulse oximetry ( r = 0.92), IHR ( r = 0.83) and HF ( r = 0.96), but somewhat less with WMH ( r = 0.62) and CAR ( r = 0.60). The accuracy of app-measured heart rate as compared to electrocardiogram, reported as mean absolute error (in bpm ± standard error) was 2 ± 0.35 (pulse oximetry), 4.5 ± 1.1 (IHR), 2 ± 0.5 (HF), 7.1 ± 1.4 (WMH) and 8.1 ± 1.4 (CAR). Conclusions We found substantial performance differences between the four studied heart rate measuring apps. The two contact photoplethysmography-based apps had higher feasibility and better accuracy for heart rate measurement than the two non-contact photoplethysmography-based apps.

  7. Ivabradine: Cardioprotection By and Beyond Heart Rate Reduction.

    Science.gov (United States)

    Heusch, Gerd; Kleinbongard, Petra

    2016-05-01

    Ivabradine inhibits hyperpolarization-activated cyclic nucleotide-gated channels in the sinus node, thereby reducing heart rate, and heart rate reduction improves regional myocardial blood flow and contractile function in ischemic myocardium. Accordingly, ivabradine reduces anginal symptoms in patients with stable coronary artery disease but does not improve their clinical outcome. Heart rate reduction with ivabradine in patients with symptomatic heart failure reduces symptoms, attenuates remodeling, and improves clinical outcome. In pigs and mice, ivabradine reduces infarct size from myocardial ischemia/reperfusion, even when heart rate reduction is abrogated by atrial pacing. Improved viability is also observed in isolated ventricular cardiomyocytes subjected to simulated ischemia/reperfusion. These beneficial effects are attributed to reduced reactive oxygen species formation from the mitochondria. There is also evidence for a heart rate-independent benefit from ivabradine in the vasculature of mice and humans, and in left ventricular contractile function of pigs. Finally, in mice, ivabradine also has anti-aging potential.

  8. Heart rate patterns in trisomic fetuses.

    Science.gov (United States)

    Kariniemi, V; Aula, P

    1982-01-01

    A survey of the clinical records of fifteen fetuses with trisomy 21, six fetuses with trisomy 18, and two fetuses with trisomy 13 was made in order to find out typical patterns of fetal heart rate (FHR) possibly associated with these conditions. Antepartal FHR patterns of 55 normal pregnancies and intrapartal FHR patterns of 14 normal labors were used as a control material. Trisomic fetuses showed significantly fewer FHR accelerations than did the controls. Fetuses with trisomy 18 and 13 had more antepartal decelerations than fetuses with trisomy 21. Trisomic fetuses also showed more intrapartal late decelerations and epochs of silent FHR pattern than did the controls. The abnormal FHR patterns of the trisomic fetuses thus were similar to those in placental insufficiency. Cesarean section was performed for both fetuses with trisomy 13, for five of the six fetuses with trisomy 18 and for nine of fifteen fetuses with trisomy 21. In eleven of sixteen cesarean sections the main indication was abnormal cardiotocogram. Fetal karyotyping from an amniotic fluid sample should perhaps be considered when decelerations and silent patterns of FHR in a growth-retarded, late second or early third trimester fetus are seen. In most cases, however, the decision for optimal management o labor must be based on FHR patterns solely.

  9. Investigation of determinism in heart rate variability

    Science.gov (United States)

    Gomes, M. E. D.; Souza, A. V. P.; Guimarães, H. N.; Aguirre, L. A.

    2000-06-01

    The article searches for the possible presence of determinism in heart rate variability (HRV) signals by using a new approach based on NARMA (nonlinear autoregressive moving average) modeling and free-run prediction. Thirty-three 256-point HRV time series obtained from Wistar rats submitted to different autonomic blockade protocols are considered, and a collection of surrogate data sets are generated from each one of them. These surrogate sequences are assumed to be nondeterministic and therefore they may not be predictable. The original HRV time series and related surrogates are submitted to NARMA modeling and prediction. Special attention has been paid to the problem of stationarity. The results consistently show that the surrogate data sets cannot be predicted better than the trivial predictor—the mean—while most of the HRV control sequences are predictable to a certain degree. This suggests that the normal HRV signals have a deterministic signature. The HRV time series derived from the autonomic blockade segments of the experimental protocols do not show the same predictability performance, albeit the physiological interpretation is not obvious. These results have important implications to the methodology of HRV analysis, indicating that techniques from nonlinear dynamics and deterministic chaos may be applied to elicit more information about the autonomic modulation of the cardiovascular activity.

  10. Depression and heart rate variability in firefighters

    Directory of Open Access Journals (Sweden)

    Li-Mei Liao

    2014-07-01

    Full Text Available Introduction: Depression has been found to increase the risk of mortality in patients with coronary artery disease through a mechanism of changing cardiac autonomic tone which is reflected by alteration of heart rate variability indices. This study investigated whether such mechanism existed in firefighters who were at high risk of depression and sudden cardiac death. Methods and results: In total, 107 firefighters were recruited. All completed Beck Depression Inventory and underwent 24-h ambulatory electrocardiographic monitoring. The root-mean-square of successive differences, standard deviation of all normal-to-normal intervals index, and the percentage of differences between adjacent normal-to-normal intervals >50 ms were significantly lower in depressed than in non-depressed firefighters after controlling for hypertension, age, and body mass index (40.1 ± 18.8 vs 62.5 ± 77.4, p < 0.01; 63.0 ± 19.2 vs 72.1 ± 34.8, p < 0.01; 8.4 ± 7.2 vs 12.7 ± 10.9, p < 0.01, respectively. Conclusion: Decreased vagal tone is a possible mechanism linking depression and sudden cardiac death in firefighters.

  11. Heart rate variability reproducibility during exercise.

    Science.gov (United States)

    McNarry, Melitta A; Lewis, Michael J

    2012-07-01

    The use of heart rate variability (HRV) parameters during exercise is not supported by appropriate reliability studies. In 80 healthy adults, ECG was recorded during three 6 min bouts of exercise, separated by 6 min of unloaded cycling. Two bouts were at a moderate intensity while the final bout was at a heavy exercise intensity. This protocol was repeated under the same conditions on three occasions, with a controlled start time (pre-determined at the first visit). Standard time and frequency domain indices of HRV were derived. Reliability was assessed by Bland–Altman plots, 95% limits of agreement and intraclass correlation coefficients (ICC). The sample size required to detect a mean difference ≥30% of the between-subject standard deviation was also estimated. There was no systematic change between days. All HRV parameters demonstrated a high degree of reproducibility during baseline (ICC range: 0.58–0.75), moderate (ICC: 0.58–0.85) and heavy intensity exercise (ICC range: 0.40–0.76). The reproducibility was slightly diminished during heavy intensity exercise relative to both unloaded baseline cycling and moderate exercise. This study indicates that HRV parameters can be reliably determined during exercise, and it underlines the importance of standardizing exercise intensity with regard to fitness levels if HRV is to be reliably determined.

  12. Heart rate variability and suicidal behavior.

    Science.gov (United States)

    Wilson, Scott T; Chesin, Megan; Fertuck, Eric; Keilp, John; Brodsky, Beth; Mann, J John; Sönmez, Cemile Ceren; Benjamin-Phillips, Christopher; Stanley, Barbara

    2016-06-30

    Identification of biological indicators of suicide risk is important given advantages of biomarker-based models. Decreased high frequency heart rate variability (HF HRV) may be a biomarker of suicide risk. The aim of this research was to determine whether HF HRV differs between suicide attempters and non-attempters. Using the Trier Social Stress Test (TSST), we compared HF HRV between females with and without a history of suicide attempt, all with a lifetime diagnosis of a mood disorder. To investigate a potential mechanism explaining association between HF HRV and suicide, we examined the association between self-reported anger and HF HRV. Results of an Area under the Curve (AUC) analysis showed attempters had a lower cumulative HF HRV during the TSST than non-attempters. In addition, while there was no difference in self-reported anger at baseline, the increase in anger was greater in attempters, and negatively associated with HF HRV. Results suggest that suicide attempters have a reduced capacity to regulate their response to stress, and that reduced capacity to regulate anger may be a mechanism through which decreased HF HRV can lead to an increase in suicide risk. Our results have implications for the prevention of suicidal behavior in at-risk populations.

  13. Drowsiness detection using heart rate variability.

    Science.gov (United States)

    Vicente, José; Laguna, Pablo; Bartra, Ariadna; Bailón, Raquel

    2016-06-01

    It is estimated that 10-30 % of road fatalities are related to drowsy driving. Driver's drowsiness detection based on biological and vehicle signals is being studied in preventive car safety. Autonomous nervous system activity, which can be measured noninvasively from the heart rate variability (HRV) signal obtained from surface electrocardiogram, presents alterations during stress, extreme fatigue and drowsiness episodes. We hypothesized that these alterations manifest on HRV and thus could be used to detect driver's drowsiness. We analyzed three driving databases in which drivers presented different sleep-deprivation levels, and in which each driving minute was annotated as drowsy or awake. We developed two different drowsiness detectors based on HRV. While the drowsiness episodes detector assessed each minute of driving as "awake" or "drowsy" with seven HRV derived features (positive predictive value 0.96, sensitivity 0.59, specificity 0.98 on 3475 min of driving), the sleep-deprivation detector discerned if a driver was suitable for driving or not, at driving onset, as function of his sleep-deprivation state. Sleep-deprivation state was estimated from the first three minutes of driving using only one HRV feature (positive predictive value 0.80, sensitivity 0.62, specificity 0.88 on 30 drivers). Incorporating drowsiness assessment based on HRV signal may add significant improvements to existing car safety systems.

  14. Heart rate regulation and extreme bradycardia in diving emperor penguins.

    Science.gov (United States)

    Meir, Jessica U; Stockard, Torre K; Williams, Cassondra L; Ponganis, Katherine V; Ponganis, Paul J

    2008-04-01

    To investigate the diving heart rate (f(H)) response of the emperor penguin (Aptenodytes forsteri), the consummate avian diver, birds diving at an isolated dive hole in McMurdo Sound, Antarctica were outfitted with digital electrocardiogram recorders, two-axis accelerometers and time depth recorders (TDRs). In contrast to any other freely diving bird, a true bradycardia (f(H) significantly emperor penguins. Maximum instantaneous surface interval f(H) in this study is the highest ever recorded for emperor penguins (256 beats min(-1)), equivalent to f(H) at V(O(2)) max., presumably facilitating oxygen loading and post-dive metabolism. The classic Scholander-Irving dive response in these emperor penguins contrasts with the absence of true bradycardia in diving ducks, cormorants, and other penguin species.

  15. Controlling the emotional heart: heart rate biofeedback improves cardiac control during emotional reactions.

    Science.gov (United States)

    Peira, Nathalie; Fredrikson, Mats; Pourtois, Gilles

    2014-03-01

    When regulating negative emotional reactions, one goal is to reduce physiological reactions. However, not all regulation strategies succeed in doing that. We tested whether heart rate biofeedback helped participants reduce physiological reactions in response to negative and neutral pictures. When viewing neutral pictures, participants could regulate their heart rate whether the heart rate feedback was real or not. In contrast, when viewing negative pictures, participants could regulate heart rate only when feedback was real. Ratings of task success paralleled heart rate. Participants' general level of anxiety, emotion awareness, or cognitive emotion regulation strategies did not influence the results. Our findings show that accurate online heart rate biofeedback provides an efficient way to down-regulate autonomic physiological reactions when encountering negative stimuli.

  16. Sleep problems and heart rate variability over the working day.

    Science.gov (United States)

    Jackowska, Marta; Dockray, Samantha; Endrighi, Romano; Hendrickx, Hilde; Steptoe, Andrew

    2012-08-01

    The purpose of this study was to discover whether greater sleep problems are associated with reduced heart rate variability during working hours and at night, and to determine whether this association is in part mediated by experienced affective states. This study involved 199 working women with a mean age of 33.8years. Sleep problems were assessed with the Jenkins Sleep Problems Scale, and the Day Reconstruction Method was used to measure positive affect and stress on the evening before and during the working day. Heart rate variability was indexed by the mean square root of the successive standard difference in heart period. Disturbed sleep was inversely related to heart rate variability during the working day (P=0.022), independently of demographic and behavioural confounders. Additional adjustment for positive affect and stress did not lead to further reductions in the association between sleep problems and reduced heart rate variability over the work day. Sleep problems were not predictive of reduced night-time heart rate variability. This report extends the findings from experimental studies and clinical samples, and suggests that disturbed sleep might impair heart rate variability in real life settings, in particular during working hours. Reduced heart rate variability might be a potential pathway linking sleep problems with cardiovascular disease. Based on the current data there was little evidence that the inverse associations between sleep problems and heart rate variability were mediated by experienced affective states.

  17. Leukotriene C4 action and metabolism in the isolated perfused bullfrog heart.

    Science.gov (United States)

    Herman, R P; Heller, R S; Canavan, C M; Herman, C A

    1988-08-01

    The effects of leukotrienes (LTs) have been widely studied in the isolated perfused mammalian heart; however, little is known about the effect or metabolism of LTs in the isolated bullfrog heart. Isolated perfused bullfrog hearts were administered randomized doses of LTC4, LTD4, or LTE4. The cardiac parameters of heart rate, developed tension, and its first derivative (dT/dt) were recorded. LTC4 was the most potent of the leukotrienes tested in eliciting positive inotropic effects. LTD4 and LTE4 were equally effective but about one order of magnitude less potent than LTC4. None of the LTs showed any chronotropic effects in this preparation. A series of [3H]LTC4 metabolism experiments were carried out using whole perfused hearts and minced bullfrog heart tissue. Isolated perfused bullfrog hearts administered [3H]LTC4 converted significant amounts to [3H]LTD4, and to a lesser degree, [3H]LTE4, during the 6-min course of collection. Both minced atrial and ventricular tissue converted [3H]LTC4 to radioactive metabolites that co-migrated with authentic LTD4 and LTE4 standards. In both tissues, the major product was [3H]LTD4, with smaller amounts of [3H]LTE4 produced. The atrium converted significantly more [3H]LTC4 to its metabolites than did the ventricle. The metabolism of [3H]LTC4 to [3H]LTD4 by both tissues was virtually abolished in the presence of serine borate. Cysteine had no effect on [3H]LTE4 production. The data in this study demonstrate that leukotrienes have the opposite inotropic effect on the heart when compared with mammals. Also in contrast to mammals, frogs metabolize LTC4 to a less potent compound and may use the LTC4 to LTD4 conversion as a mechanism of LTC4 inactivation.

  18. Aerobic exercise during pregnancy influences fetal cardiac autonomic control of heart rate and heart rate variability.

    Science.gov (United States)

    May, Linda E; Glaros, Alan; Yeh, Hung-Wen; Clapp, James F; Gustafson, Kathleen M

    2010-04-01

    Previous studies using ultrasound technology showed that fetal heart rate (HR) may be responsive to maternal aerobic exercise. Although it is recognized that cardiac autonomic control may be influenced by the intrauterine environment, little is known about how maternal exercise affects fetal heart development. This study tested the hypothesis that regular maternal exercise throughout gestation influences fetal cardiac autonomic control of HR and heart rate variability (HRV) when compared to fetuses of non-exercising women. Magnetocardiograms (MCGs) were recorded using a dedicated fetal biomagnetometer at 28, 32 and 36 weeks gestational age (GA) from 26 regularly exercising (>30 min of aerobic exercise, 3x per week) and 35 healthy, non-exercising pregnant women. Fetal MCG was isolated and normal R-peaks were marked to derive fetal HR and HRV in the time and frequency domains. We applied a mixed-effects model to investigate the effects of exercise, GA and fetal activity state. At 36 weeks GA, during the active fetal state, fetal HR was significantly lower in the exercise group (p=exercise group during the active fetal state at 36 weeks GA for both time and frequency domain measures. These results indicate that regular maternal exercise throughout gestation results in significantly lower fetal HR and increased HRV. 2010 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

    Osadchii, Oleg E

    2014-12-01

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

  20. HEART RATE DURING SLEEP: IMPLICATIONS FOR MONITORING TRAINING STATUS

    Directory of Open Access Journals (Sweden)

    Miriam R. Waldeck

    2003-12-01

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

  1. Heart Rate and Cardiovascular Disease: An Alternative to Beta Blockers

    Directory of Open Access Journals (Sweden)

    Michael Liang

    2009-01-01

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

  2. Cardiac rehabilitation programs improve metabolic parameters in patients with the metabolic syndrome and coronary heart disease.

    Science.gov (United States)

    Pérez, Ignacio P; Zapata, Maria A; Cervantes, Carlos E; Jarabo, Rosario M; Grande, Cristina; Plaza, Rose; Garcia, Sara; Rodriguez, Miriam L; Crespo, Silvia; Perea, Jesús

    2010-05-01

    This study was performed to determine the effectiveness of a cardiac rehabilitation and exercise training program on metabolic parameters and coronary risk factors in patients with the metabolic syndrome and coronary heart disease. The study involved 642 patients with coronary heart disease. Of them, 171 (26.7%) fulfilled criteria for the metabolic syndrome. Clinical data, laboratory tests, and exercise testing were performed before and after the program, which lasted 2 to 3 months. Except for waist circumference, there were no significant differences between groups; blood pressure, high-density lipoprotein cholesterol, triglycerides, and fasting glucose improvements during the follow-up were higher in patients with the metabolic syndrome (all Pmetabolic syndrome, functional capacity increased by 26.45% ( Pmetabolic equivalents, with a slight increase of 1.25% ( P=not significant) in the double product. Patients with the metabolic syndrome who took part in this secondary prevention program reported improvements in cardiovascular risk profile and functional capacity.

  3. MITOCHONDRIAL AND METABOLIC GENE EXPRESSION IN THE AGED RAT HEART

    Directory of Open Access Journals (Sweden)

    Gregory P Barton

    2016-08-01

    Full Text Available Aging is associated with a decline in cardiac function. Exercise intervention has been suggested as a way to improve this decrement. Age-related decline in cardiac function is associated with decreases in fatty acid oxidation, mitochondrial function and AMP-activated protein kinase (AMPK activity. The molecular mechanisms involved with age-related changes in mitochondrial function and substrate metabolism are poorly understood. We determined gene expression differences in hearts of Young (6 mo, Old (33 mo, and old exercise trained (Old + EXE (34 mo FBN rats, using Qiagen PCR arrays for Glucose, Fatty acid, and Mitochondrial metabolism. Old rats demonstrated decreased (p < 0.05 expression for key genes in fatty acid oxidation, mitochondrial function, and AMPK signaling. There were no differences in the expression of genes involved in glucose metabolism with age. These gene expression changes occurred prior to altered protein translation as we found no differences in the protein content of peroxisome proliferator activated receptor gamma, coactivators 1 alpha (PGC-1α, peroxisome proliferator activated receptor alpha (PPARα, and AMPKα2 between young and old hearts. Four months of exercise training did not attenuate the decline in the gene expression in aged hearts. Despite this lack of change in gene expression, exercise-trained rats demonstrated increased exercise capacity compared to their sedentary counterparts. Taken together, our results show that differential expression of genes associated with fatty acid metabolism, AMPK signaling and mitochondrial function are superfluous and decrease in the aging heart which may play a role in age-related declines in fatty acid oxidation, AMPK activity and mitochondrial function in the heart.

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

    NARCIS (Netherlands)

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

    2015-01-01

    Heart rate is a useful neurophysiological sign when monitoring seizures in patients with epilepsy. In an ambulatory setting, heart rate is measured with ECG involving electrodes on the skin. This method is uncomfortable which is burdensome for patients and is sensitive to motion artifacts, which dec

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

    NARCIS (Netherlands)

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

    2015-01-01

    Heart rate is a useful neurophysiological sign when monitoring seizures in patients with epilepsy. In an ambulatory setting, heart rate is measured with ECG involving electrodes on the skin. This method is uncomfortable which is burdensome for patients and is sensitive to motion artifacts, which

  6. Fetal Behavior and Heart Rate in Twin Pregnancy : A Review

    NARCIS (Netherlands)

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

    2013-01-01

    Fetal movements and fetal heart rate (FHR) are well-established markers of fetal well-being and maturation of the fetal central nervous system. The purpose of this paper is to review and discuss the available knowledge on fetal movements and heart rate patterns in twin pregnancies. There is some evi

  7. Effect of Age and Other Factors on Maximal Heart Rate.

    Science.gov (United States)

    Londeree, Ben R.; Moeschberger, Melvin L.

    1982-01-01

    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)

  8. A comparison between heart rate and heart rate variability as indicators of cardiac health and fitness

    Directory of Open Access Journals (Sweden)

    Catharina Cornelia Grant

    2013-11-01

    Full Text Available Quantification of cardiac autonomic activity and control via heart rate (HR and heart rate variability (HRV is known to provide prognostic information in clinical populations. Issues with regard to standardisation and interpretation of HRV data make the use of the more easily accessible HR on its own as an indicator of autonomic cardiac control very appealing. The aim of this study was to investigate the strength of associations between an important cardio vascular health metric such as VO2max and the following: HR, HRV indicators and heart rate normalised HRV indicators. A cross sectional descriptive study was done including 145 healthy volunteers aged between 18 and 22 years. HRV was quantified by time domain, frequency domain and Poincaré plot analysis. Indirect VO2max was determined using the Multistage Coopers test. The Pearson correlation coefficient was calculated to quantify the strength of the associations. Both simple linear and multiple stepwise regressions were performed to be able to discriminate between the role of the individual indicators as well as their combined association with VO2max. Only HR, RR interval and pNN50 showed significant (p<0.01, p<0.01 and p=0.03 correlations with VO2max. Stepwise multiple regression indicated that, when combining all HRV indicators the most important predictor of cardio vascular fitness as represented by VO2max, is HR. HR explains 17% of the variation, while the inclusion of HF (high frequency HRV indicator added only an additional 3.1% to the coefficient of determination. Results also showed when testing the normalised indicators, HR explained of the largest percentage of the changes in VO2max (16.5%. Thus HR on its own is the most important predictor of changes in an important cardiac health metric such as VO2max. These results may indicate that during investigation of exercise ability (VO2max phenomena, quantification of HRV may not add significant value.

  9. Effects of Tai Chi exercise on heart rate variability.

    Science.gov (United States)

    Cole, Aimee R; Wijarnpreecha, Karn; Chattipakorn, Siriporn C; Chattipakorn, Nipon

    2016-05-01

    Tai Chi is a callisthenic exercise form that incorporates aerobic exercise with diaphragmatic breathing. These two aspects alone have been shown to enhance the heart rate variability, warranting research into the effects of Tai Chi on autonomic nervous system modulation and heart rate variability. A low heart rate variability has been shown to be indicative of compromised health. Any methods to enhance the heart rate variability, in particular, non-pharmacological methods, are therefore seen as beneficial to health and are sought after. The aim of this review was to comprehensively summarize the currently published studies regarding the effects of Tai Chi on heart rate variability. Both consistent and inconsistent findings are presented and discussed, and an overall conclusion attained which could benefit future clinical studies. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

    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…

  11. The clinical significance of detection to heart rate deceleration capacity and heart rate variability in patients with chronic heart failure

    Directory of Open Access Journals (Sweden)

    Jiang-rong Zhou

    2015-01-01

    Full Text Available Objective: To study the change of heart rate deceleration capacity ( DC and heart rate variability in patients with chronic heart failure (CHF and its relationship with left ventricular ejection fraction (LVEF. Methods: DC, LVEF, time and frequency domain parameters of HRV were measured in 66 patients with CHF and 34 healthy adults (control group by using 24h Holter recordings and Echocardiography. The standard deviation of normal R-R intervals( SDNN, squares of differences between adjacent NN intervals ( RMSSD,low frequency power( LFn and high frequency power( HFn and the changes of LVEF were compared between  the two groups,the relationship between DC,LVEF and HRV were studied in patients with CHF. Results: The median value of DC in the patients with CHF was significantly lower than that in control group( 3.1 ± 2.4 ms vs 7.2 ± 1.3 ms,P <0.01.Incidence of abnormal DC in the CHF group was 57.5%,which was significantly higher than that in the control group (P <0.01.The HRV index, including SDNN、RMSSD、LFn、HFn, in the CHF group was significantly lower than that in normal control group (P < 0.01. Significant positive correlation between HRV index and LVEF were confirmed (P < 0.01. Conclusions: DC and HRV index are lower in patients with CHF and have a good correlation with the left ventricular ejection fraction.

  12. Long‐term Cardiovascular Risks Associated With an Elevated Heart Rate: The Framingham Heart Study

    Science.gov (United States)

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

    2014-01-01

    Background Higher heart rate has been associated with an adverse prognosis, but most prior studies focused on individuals with known cardiovascular disease or examined a limited number of outcomes. We sought to examine the association of baseline heart rate with both fatal and nonfatal outcomes during 2 decades of follow‐up. Methods and Results Our study included 4058 Framingham Heart Study participants (mean age 55 years, 56% women). Cox models were performed with multivariable adjustment for clinical risk factors and physical activity. A total of 708 participants developed incident cardiovascular disease (303 heart failure, 343 coronary heart disease, and 216 stroke events), 48 received a permanent pacemaker, and 1186 died. Baseline heart rate was associated with incident cardiovascular disease (hazard ratio [HR] 1.15 per 1 SD [11 bpm] increase in heart rate, 95% CI 1.07 to 1.24, P=0.0002), particularly heart failure (HR 1.32, 95% CI 1.18 to 1.48, Pheart rate was also associated with higher all‐cause (HR 1.17, 95% CI 1.11 to 1.24, Pheart 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

  13. [Heart rate measurement algorithm based on artificial intelligence].

    Science.gov (United States)

    Chengxian, Cai; Wei, Wang

    2010-01-01

    Based on the heart rate measurement method using time-lapse image of human cheek, this paper proposes a novel measurement algorithm based on Artificial Intelligence. The algorithm combining with fuzzy logic theory acquires the heart beat point by using the defined fuzzy membership function of each sampled point. As a result, it calculates the heart rate by counting the heart beat points in a certain time period. Experiment shows said algorithm satisfies in operability, accuracy and robustness, which leads to constant practical value.

  14. Effects of Exercise During Pregnancy on Maternal Heart Rate and Heart Rate Variability.

    Science.gov (United States)

    May, Linda E; Knowlton, Jennifer; Hanson, Jessica; Suminski, Richard; Paynter, Christopher; Fang, Xiangming; Gustafson, Kathleen M

    2016-07-01

    Pregnancy is associated with an increased sympathetic state, which can be exacerbated by gestational conditions. Research has shown that exercise during pregnancy lowers heart rate (HR) and can attenuate the symptoms of gestational conditions associated with increased sympathetic control. However, changes in maternal heart autonomic function in response to exercise have not been reported across multiple time points during pregnancy. This analysis is designed to address this gap. To determine if exercise throughout gestation improves maternal cardiac autonomic nervous system functioning, as evidenced by decreased HR and increased heart rate variability (HRV) indices. Case control study. Academic medical institution. A total of 56 women with healthy, singleton, low-risk pregnancies. Participants were asked to complete 3 resting 18-minute HRV recordings at 28, 32, and 36 weeks' gestation, along with a physical activity questionnaire. HRV indices were calculated for time (R peak to R peak interval standard deviation and root mean squared of successive differences) and frequency (very low, low, and high frequency) domain measures. The differences between groups were compared for HRV indices at 28, 32, and 36 weeks. Resting HR was significantly lower in the exercise group at 28 weeks (P exercise group had significantly (P exercise group relative to the control group. No differences occurred in sympathovagal balance (low frequency/high frequency ratio) between groups. Exercise throughout pregnancy can significantly improve cardiac autonomic control. More research is needed to determine if this adaptation to exercise may reduce the risk of adverse outcomes associated with gestational conditions with poor autonomic control, such as diabetes, hypertension, pre-eclampsia, and excessive weight gain. Copyright © 2016 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

  15. Population characteristics and impact on heart rate variability,heart rate and blood pressure of passive smoking

    Institute of Scientific and Technical Information of China (English)

    赵菁

    2013-01-01

    Objective To investigate the basic characteristics of passive smoking population,and the impact of passive smoking on heart rate variability,heart rate and blood pressure.Methods Eighty-six passive smokers[mean age: (52.4±7.6) years]were recruited from patients

  16. Job strain in relation to ambulatory blood pressure, heart rate, and heart rate variability among female nurses

    NARCIS (Netherlands)

    Riese, H.; Doornen, L.J.P. van; Houtman, I.L.D.; Geus, E.J.C. de

    2004-01-01

    Objective. This study examined the effects of exposure to job strain on independent predictors of cardiovascular disease (ambulatory blood pressure, heart rate, and heart rate variability). Methods. The participants comprised a homogeneous group of 159 healthy female nurses [mean age 35.9 (SD 8.5)

  17. A point-process model of human heartbeat intervals: new definitions of heart rate and heart rate variability.

    Science.gov (United States)

    Barbieri, Riccardo; Matten, Eric C; Alabi, Abdulrasheed A; Brown, Emery N

    2005-01-01

    Heart rate is a vital sign, whereas heart rate variability is an important quantitative measure of cardiovascular regulation by the autonomic nervous system. Although the design of algorithms to compute heart rate and assess heart rate variability is an active area of research, none of the approaches considers the natural point-process structure of human heartbeats, and none gives instantaneous estimates of heart rate variability. We model the stochastic structure of heartbeat intervals as a history-dependent inverse Gaussian process and derive from it an explicit probability density that gives new definitions of heart rate and heart rate variability: instantaneous R-R interval and heart rate standard deviations. We estimate the time-varying parameters of the inverse Gaussian model by local maximum likelihood and assess model goodness-of-fit by Kolmogorov-Smirnov tests based on the time-rescaling theorem. We illustrate our new definitions in an analysis of human heartbeat intervals from 10 healthy subjects undergoing a tilt-table experiment. Although several studies have identified deterministic, nonlinear dynamical features in human heartbeat intervals, our analysis shows that a highly accurate description of these series at rest and in extreme physiological conditions may be given by an elementary, physiologically based, stochastic model.

  18. Job strain in relation to ambulatory blood pressure, heart rate, and heart rate variability among female nurses

    NARCIS (Netherlands)

    Riese, H.; Doornen, L.J.P. van; Houtman, I.L.D.; Geus, E.J.C. de

    2004-01-01

    Objective. This study examined the effects of exposure to job strain on independent predictors of cardiovascular disease (ambulatory blood pressure, heart rate, and heart rate variability). Methods. The participants comprised a homogeneous group of 159 healthy female nurses [mean age 35.9 (SD 8.5) y

  19. Heart Rate Responses to Synthesized Affective Spoken Words

    Directory of Open Access Journals (Sweden)

    Mirja Ilves

    2012-01-01

    Full Text Available The present study investigated the effects of brief synthesized spoken words with emotional content on the ratings of emotions and heart rate responses. Twenty participants' heart rate functioning was measured while they listened to a set of emotionally negative, neutral, and positive words produced by speech synthesizers. At the end of the experiment, ratings of emotional experiences were also collected. The results showed that the ratings of the words were in accordance with their valence. Heart rate deceleration was significantly the strongest and most prolonged to the negative stimuli. The findings are the first suggesting that brief spoken emotionally toned words evoke a similar heart rate response pattern found earlier for more sustained emotional stimuli.

  20. Resting heart rate variability and heart rate recovery after submaximal exercise.

    Science.gov (United States)

    Danieli, Aljoša; Lusa, Lara; Potočnik, Nejka; Meglič, Bernard; Grad, Anton; Bajrović, Fajko F

    2014-04-01

    Aerobic training accelerates Heart Rate Recovery after exercise in healthy subjects and in patients with coronary disease. As shown by pharmacological autonomic blockade, HRR early after exercise is dependent primarily on parasympathetic reactivation. Thus, accelerated HRR early after exercise in endurance-trained athletes may be attributed to augmented parasympathetic reactivation. In the present study, we tested the hypothesis that the HRR early after submaximal exercise is related to the pre-exercise parasympathetic modulation. Thirty endurance-trained athletes (20 males, 50 ± 7 years) and thirty control subjects (20 males, 52 ± 6 years) performed a submaximal exercise on a cyclo-ergometer. Pre-exercise resting short-term heart rate variability (HRV) parameters in time and frequency-domains were correlated with HRR during the first 30 s, 1 and 2 min after cessation of exercise. We found that HRR was statistically significantly faster in athletes than in controls at all examination time points (p exercise is related to resting parasympathetic modulation in the middle-aged subjects. In addition, they suggested an optimal range of HRV for maximal HRR after exercise.

  1. The effect of relaxing massage on heart rate and heart rate variability in purebred Arabian racehorses.

    Science.gov (United States)

    Kowalik, Sylwester; Janczarek, Iwona; Kędzierski, Witold; Stachurska, Anna; Wilk, Izabela

    2017-04-01

    The objective of this study was to assess the effect of relaxing massage on the heart rate (HR) and heart rate variability (HRV) in young racehorses during their first racing season. In the study, 72 Purebred Arabian racehorses were included. The study was implemented during the full race season. The horses from control and experimental groups were included in regular race training 6 days a week. The horses from the experimental group were additionally subject to the relaxing massage 3 days a week during the whole study. HR and HRV were assumed as indicators of the emotional state of the horses. The measurements were taken six times, every 4-5 weeks. The HRV parameters were measured at rest, during grooming and saddling the horse and during warm-up walking under a rider. The changes of the parameters throughout the season suggest that the relaxing massage may be effectively used to make the racehorses more relaxed and calm. Moreover, the horses from the experimental group had better race performance records. © 2016 Japanese Society of Animal Science.

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

    Science.gov (United States)

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

    2014-01-01

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

  3. Fighter pilots' heart rate, heart rate variation and performance during instrument approaches.

    Science.gov (United States)

    Mansikka, Heikki; Simola, Petteri; Virtanen, Kai; Harris, Don; Oksama, Lauri

    2016-10-01

    Fighter pilots' heart rate (HR), heart rate variation (HRV) and performance during instrument approaches were examined. The subjects were required to fly instrument approaches in a high-fidelity simulator under various levels of task demand. The task demand was manipulated by increasing the load on the subjects by reducing the range at which they commenced the approach. HR and the time domain components of HRV were used as measures of pilot mental workload (PMWL). The findings of this study indicate that HR and HRV are sensitive to varying task demands. HR and HRV were able to distinguish the level of PMWL after which the subjects were no longer able to cope with the increasing task demands and their instrument landing system performance fell to a sub-standard level. The major finding was the HR/HRV's ability to differentiate the sub-standard performance approaches from the high-performance approaches. Practitioner Summary: This paper examined if HR and HRV were sensitive to varying task demands in a fighter aviation environment and if these measures were related to variations in pilot's performance.

  4. Improvements in fetal heart rate analysis by the removal of maternal-fetal heart rate ambiguities.

    Science.gov (United States)

    Pinto, Paula; Costa-Santos, Cristina; Gonçalves, Hernâni; Ayres-De-Campos, Diogo; Bernardes, João

    2015-11-19

    Misinterpretation of the maternal heart rate (MHR) as fetal may lead to significant errors in fetal heart rate (FHR) interpretation. In this study we hypothesized that the removal of these MHR-FHR ambiguities would improve FHR analysis during the final hour of labor. Sixty-one MHR and FHR recordings were simultaneously acquired in the final hour of labor. Removal of MHR-FHR ambiguities was performed by subtracting MHR signals from their FHR counterparts when the absolute difference between the two was less or equal to 5 beats per minute. Major MHR-FHR ambiguities were defined when they exceeded 1% of the tracing. Maternal, fetal and neonatal characteristics were evaluated in cases where major MHR-FHR ambiguities occurred and computer analysis of FHR recordings was compared, before and after removal of the ambiguities. Seventy-two percent of tracings (44/61) exhibited episodes of major MHR-FHR ambiguities, which were not significantly associated with any maternal, fetal or neonatal characteristics, but were associated with MHR accelerations, FHR signal loss and decelerations. Removal of MHR-FHR ambiguities resulted in a significant decrease in FHR decelerations, and improvement in FHR tracing classification. FHR interpretation during the final hour of labor can be significantly improved by the removal of MHR-FHR ambiguities.

  5. Effect of yoga therapy on heart rate, blood pressure and cardiac autonomic function in heart failure.

    Science.gov (United States)

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

    2014-01-01

    It is well known that a hall mark of heart failure is adverse changes in autonomic function. Elevated blood pressure is a powerful predictor of congestive heart failure and other Cardiovascular Disease (CVD) outcomes. In this study, we planned to examine the effects of a 12 week yoga therapy on blood pressure, heart rate, heart rate variability, and rate pressure product (RPP). Out of 130 heart failure patients recruited for the study, 65 patients were randomly selected to receive 12 week yoga therapy along with standard medical therapy (yoga group). Other patients (n=65) received only standard medical therapy (control group). Heart rate, blood pressure, cardiac autonomic function (by short-term heart-rate variability analysis) and myocardial oxygen consumption (by RPP) were assessed before and after 12 weeks. In the yoga group, 44 patients and in the control group, 48 patients completed the study. There was a significant decrease in heart rate, blood pressure and RPP in yoga group compared to control group. Also, LFnu and LF-HF ratio decreased significantly and HFnu increased significantly in yoga group compared to control group. Twelve-week yoga therapy significantly improved the parasympathetic activity and decreased the sympathetic activity in heart failure patients (NYHA I&II).

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

    OpenAIRE

    Vitor Oliveira Carvalho; Guilherme Veiga Guimarães; Emmanuel Gomes Ciolac; Edimar Alcides Bocchi

    2008-01-01

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

  7. Lipid metabolism in the heart. Contribution of BMIPP to the diseased heart

    Energy Technology Data Exchange (ETDEWEB)

    Nohara, Ryuji [Tazuke Kofukai Medical Research Inst., Osaka (Japan). Kitano Hospital

    2001-10-01

    Lipid contributes greatly in cardiac metabolism to produce high energy ATPs, and is suggested to be related to the progression and deterioration of heart disease. It is fortunate that the I-123-betamethyliodophenylpentadecanoic acid (BMIPP) imaging technique is now available in determining heart condition, but we must be cautious about the interpretation of images obtained with new tracer. From the uptake of BMIPP into the cell to breakdown and catabolism of it, there exist so many critical enzymatical pathways relating to the modification of BMIPP imaging. In clinical evaluation, the image will be translated as the integral effects of these pathways. In order words, we must be aware of these critical pathways regulating lipid metabolism and modifying factors in order to correctly understand BMIPP imaging. Lipid transport is affected by the albumin/FFA ratio in the blood, and extraction with membrane transporter proteins. Fatty acid binding protein (FABP) in the cytosole will play an important role in regulating lipid flux and following metabolism. Lipid will be utilized either for oxidation, triglyceride or phospholipid formation. For oxidation, carnitine palmitoil transferase is the key enzyme for the entrance of lipid into mitochondria, and oxidative enzymes such as acyl CoA dehydrogenase (MCAD, LCAD, HAD) will determine lipid use for the TCA cycle. ATPs produced in the mitochondria again limit the TG store. It is well known that BMIPP imaging completely changes in the ischemic condition, and is also shown that lipid metabolical regulation completely differs from normal in the very early phase of cardiac hypertrophy. In the process of deteriorating heart failure, metabolical switching of lipid with glucose will take place. In such a different heart disease conditions, it is clear that lipid metabolical regulation, including many lipid enzymes, works differently from in the healthy condition. These lipid enzymes are regulated by nuclear factor peroxisome

  8. Fetal Heart Rate Monitoring from Phonocardiograph Signal Using Repetition Frequency of Heart Sounds

    Directory of Open Access Journals (Sweden)

    Hong Tang

    2016-01-01

    Full Text Available As a passive, harmless, and low-cost diagnosis tool, fetal heart rate (FHR monitoring based on fetal phonocardiography (fPCG signal is alternative to ultrasonographic cardiotocography. Previous fPCG-based methods commonly relied on the time difference of detected heart sound bursts. However, the performance is unavoidable to degrade due to missed heart sounds in very low signal-to-noise ratio environments. This paper proposes a FHR monitoring method using repetition frequency of heart sounds. The proposed method can track time-varying heart rate without both heart sound burst identification and denoising. The average accuracy rate comparison to benchmark is 88.3% as the SNR ranges from −4.4 dB to −26.7 dB.

  9. Fractal and complexity measures of heart rate variability.

    Science.gov (United States)

    Perkiömäki, Juha S; Mäkikallio, Timo H; Huikuri, Heikki V

    2005-01-01

    Heart rate variability has been analyzed conventionally with time and frequency domain methods, which measure the overall magnitude of RR interval fluctuations around its mean value or the magnitude of fluctuations in some predetermined frequencies. Analysis of heart rate dynamics by methods based on chaos theory and nonlinear system theory has gained recent interest. This interest is based on observations suggesting that the mechanisms involved in cardiovascular regulation likely interact with each other in a nonlinear way. Furthermore, recent observational studies suggest that some indexes describing nonlinear heart rate dynamics, such as fractal scaling exponents, may provide more powerful prognostic information than the traditional heart rate variability indexes. In particular, the short-term fractal scaling exponent measured by the detrended fluctuation analysis method has predicted fatal cardiovascular events in various populations. Approximate entropy, a nonlinear index of heart rate dynamics, that describes the complexity of RR interval behavior, has provided information on the vulnerability to atrial fibrillation. Many other nonlinear indexes, e.g., Lyapunov exponent and correlation dimensions, also give information on the characteristics of heart rate dynamics, but their clinical utility is not well established. Although concepts of chaos theory, fractal mathematics, and complexity measures of heart rate behavior in relation to cardiovascular physiology or various cardiovascular events are still far away from clinical medicine, they are a fruitful area for future research to expand our knowledge concerning the behavior of cardiovascular oscillations in normal healthy conditions as well as in disease states.

  10. Heart Rate Variability Measures and Models

    CERN Document Server

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

    2001-01-01

    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...

  11. Stochastic heart-rate model can reveal pathologic cardiac dynamics

    Science.gov (United States)

    Kuusela, Tom

    2004-03-01

    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.

  12. Scaling Behaviour and Memory in Heart Rate of Healthy Human

    Institute of Scientific and Technical Information of China (English)

    CAI Shi-Min; PENG Hu; YANG Hui-Jie; ZHOU Tao; ZHOU Pei-Ling; WANG Bing-Hong

    2007-01-01

    We investigate a set of complex heart rate time series from healthy human in different behaviour states with the detrended fluctuation analysis and diffusion entropy (DE) method. It is proposed that the scaling properties are influenced by behaviour states. The memory detected by DE exhibits an approximately same pattern after a detrending procedure. Both of them demonstrate the long-range strong correlations in heart rate. These findings may be helpful to understand the underlying dynamical evolution process in the heart rate control system, as well as to model the cardiac dynamic process.

  13. Heart rate, heart rate variability, and arrhythmias in dogs with myxomatous mitral valve disease

    DEFF Research Database (Denmark)

    Rasmussen, Caroline Elisabeth; Falk, Bo Torkel; Zois, Nora Elisabeth

    2012-01-01

    Autonomic modulation of heart rhythm is thought to influence the pathophysiology of myxomatous mitral valve disease (MMVD).......Autonomic modulation of heart rhythm is thought to influence the pathophysiology of myxomatous mitral valve disease (MMVD)....

  14. A comparison between heart rate and heart rate variability as indicators of cardiac health and fitness.

    Science.gov (United States)

    Grant, Catharina C; Murray, Carien; Janse van Rensburg, Dina C; Fletcher, Lizelle

    2013-01-01

    Quantification of cardiac autonomic activity and control via heart rate (HR) and heart rate variability (HRV) is known to provide prognostic information in clinical populations. Issues with regard to standardization and interpretation of HRV data make the use of the more easily accessible HR on its own as an indicator of autonomic cardiac control very appealing. The aim of this study was to investigate the strength of associations between an important cardio vascular health metric such as VO2max and the following: HR, HRV indicators, and HR normalized HRV indicators. A cross sectional descriptive study was done including 145 healthy volunteers aged between 18 and 22 years. HRV was quantified by time domain, frequency domain and Poincaré plot analysis. Indirect VO2max was determined using the Multistage Coopers test. The Pearson correlation coefficient was calculated to quantify the strength of the associations. Both simple linear and multiple stepwise regressions were performed to be able to discriminate between the role of the individual indicators as well as their combined association with VO2max. Only HR, RR interval, and pNN50 showed significant (p VO2max. Stepwise multiple regression indicated that, when combining all HRV indicators the most important predictor of cardio vascular fitness as represented by VO2max, is HR. HR explains 17% of the variation, while the inclusion of HF (high frequency HRV indicator) added only an additional 3.1% to the coefficient of determination. Results also showed when testing the normalized indicators, HR explained of the largest percentage of the changes in VO2max (16.5%). Thus, HR on its own is the most important predictor of changes in an important cardiac health metric such as VO2max. These results may indicate that during investigation of exercise ability (VO2max) phenomena, quantification of HRV may not add significant value.

  15. Behaviour, heart rate, and heart rate variability in pigs exposed to novelty

    Directory of Open Access Journals (Sweden)

    Manja Zupan

    2016-03-01

    Full Text Available ABSTRACT In the present study, we investigated behavioural responses and determined parameters of heart rate variability (HRV to elucidate a relative activation of autonomic nervous system (ANS during baseline (10 min and in response to potentially stressful situations (10 min in two pig breeds and sexes. Gilts (n = 21 and barrows (n = 9 of the Landrace × Yorkshire (LY; n = 15 and Landrace/Yorkshire × Landrace/Duroc (LYLD; n = 15 breeds were subjected to a novel object test (NOT and a novel arena test (NAT. Basal ANS state differed in pigs across breeds but not sexes. Landrace × Yorkshire pigs had a significantly lower basal heart rate (HR and low-frequency band (LF with a higher root mean square of successive interbeat intervals (RMSSD and high-frequency band (HF than LYLD pigs. In the NOT, despite having similar cardiac responses, gilts had a longer duration of contact with a novel object, higher lying and standing duration, and a lower duration of walking compared with barrows. In the NAT, we found similar behaviour across sexes but a different degree of ANS state, with barrows having a significantly higher increase in LF/HF (power of the low frequency component divided by the power of the high-frequency band compared with gilts. Landrace/Yorkshire × Landrace/Duroc pigs showed longer duration of contact with a novel object in the NOT accompanied by less lying and standing than LY pigs in both tests. No difference in ANS activation between breeds was found in the NOT. In the NAT, HR increased more from baseline to testing in LY pigs than in LYLD pigs. There is a complex and often contradictory nature of relationships between behaviour and cardiac responses to novelty in pigs of different breeds and sexes.

  16. Heart rate responses induced by acoustic tempo and its interaction with basal heart rate

    Science.gov (United States)

    Watanabe, Ken; Ooishi, Yuuki; Kashino, Makio

    2017-01-01

    Many studies have revealed the influences of music on the autonomic nervous system (ANS). Since previous studies focused on the effects of acoustic tempo on the ANS, and humans have their own physiological oscillations such as the heart rate (HR), the effects of acoustic tempo might depend on the HR. Here we show the relationship between HR elevation induced by acoustic tempo and individual basal HR. Since high tempo-induced HR elevation requires fast respiration, which is based on sympatho-respiratory coupling, we controlled the participants’ respiration at a faster rate (20 CPM) than usual (15 CPM). We found that sound stimuli with a faster tempo than the individual basal HR increased the HR. However, the HR increased following a gradual increase in the acoustic tempo only when the extent of the gradual increase in tempo was within a specific range (around + 2%/min). The HR did not follow the increase in acoustic tempo when the rate of the increase in the acoustic tempo exceeded 3% per minute. These results suggest that the effect of the sympatho-respiratory coupling underlying the HR elevation caused by a high acoustic tempo depends on the basal HR, and the strength and the temporal dynamics of the tempo. PMID:28266647

  17. [Typical spontaneous changes in heart rate in pheochromocytoma].

    Science.gov (United States)

    Bramann, H U; Zidek, W; Vetter, H; Grosse-Heitmeyer, W

    1985-01-01

    Investigations in 13 hospitalized patients with pheochromocytomata showed peculiar characteristics of heart rate variation at rest, when compared with normals. All patients were given alpha- and beta-sympatholytic drugs. In one case alpha-methyl-Tyrosine caused I-II degree AV blocks and a stable high frequency sinus rate without physiological variations. Resting heart rate in pheochromocytoma varied interindividually from 55-105/min, in the absence of clinical attacks of the underlying disease. The frequency profile was characterized in 12 patients by sudden and inadequate rises of heart rate (200%) of short duration, which were often recorded within 20 seconds of the onset of muscular activity. A similar but less pronounced heart rate modulation was found 1-2 weeks after operation in 3 cases. Our observations indicate that the heart rate profile described may be a sensitive parameter of dysfunction of the autonomous nervous system in pheochromocytoma. Whether the heart rate characteristics are of diagnostic value has to be assessed by further studies.

  18. Acute stress affects heart rate variability during sleep

    National Research Council Canada - National Science Library

    Hall, Martica; Vasko, Raymond; Buysse, Daniel; Ombao, Hernando; Chen, Qingxia; Cashmere, J David; Kupfer, David; Thayer, Julian F

    2004-01-01

    .... In this study, we used autoregressive spectral analysis of the electrocardiogram (EKG) interbeat interval sequence to characterize stress-related changes in heart rate variability during sleep in 59 healthy men and women. Participants (N = 59...

  19. Arduino-based noise robust online heart-rate detection.

    Science.gov (United States)

    Das, Sangita; Pal, Saurabh; Mitra, Madhuchhanda

    2017-04-01

    This paper introduces a noise robust real time heart rate detection system from electrocardiogram (ECG) data. An online data acquisition system is developed to collect ECG signals from human subjects. Heart rate is detected using window-based autocorrelation peak localisation technique. A low-cost Arduino UNO board is used to implement the complete automated process. The performance of the system is compared with PC-based heart rate detection technique. Accuracy of the system is validated through simulated noisy ECG data with various levels of signal to noise ratio (SNR). The mean percentage error of detected heart rate is found to be 0.72% for the noisy database with five different noise levels.

  20. Method of Discriminant Gravity Tolerance using Heart Rate Variability

    Science.gov (United States)

    Yoshida, Yutaka; Yokoyama, Kiyoko; Takada, Hiroki; Iwase, Satoshi

    When returning on the earth by the space flight, the space deconditioning may be developed. As this countermeasure, the artificial gravity load device using the centrifuge is proposed in the space station. But the gravity load might cause the faint, and safe gravity load is uncertainty. We proposed that discriminate strength of gravity tolerance using heart rate variability time series. Step function was inputted to AR model estimated from heart rate variability time series during rest or under light gravity load, and strength of the gravity tolerance was discriminated by the step response function. On the result, discriminant accuracy was 87.5% by using heart rate variability time series when gravity load of 1.0 G was added to the human lying on the supine. Therefore, possibility of discriminant of gravity tolerance was obtained by using heart rate variability time series when sympathetic hyperactivity. Discriminant of the gravity tolerance is expected before countermeasure of space deconditioning is executed.

  1. Effects of Interval Training Programme on Resting Heart Rate in ...

    African Journals Online (AJOL)

    Effects of Interval Training Programme on Resting Heart Rate in Subjects ... Results: Findings of the study revealed significant effect of exercise training program on HR. Also, changes in V02max negatively correlated with changes in HR (r= ...

  2. Effects of Interval Training Programme on Resting Heart Rate in ...

    African Journals Online (AJOL)

    DATONYE ALASIA

    significant effect of exercise training program on HR. Also ... diseases, with a major impact on morbidity and. [1] mortality . ... Type of Article: Original. Page 26 ... Resting Heart Rate in Subjects with Hypertension — Lamina S. et al investigate ...

  3. Continuous measurement of heart rate variability following carbon ...

    African Journals Online (AJOL)

    2010-07-16

    Jul 16, 2010 ... Studies using HRV analysis during positive-pressure ... Keywords: heart rate variability; positive pressure pneumoperitoneum; continuous monitoring. Abstract .... entropy predicts arterial blood pressure fluctuation during the.

  4. Heart Rate at Hospital Discharge in Patients With Heart Failure Is Associated With Mortality and Rehospitalization

    Science.gov (United States)

    Laskey, Warren K.; Alomari, Ihab; Cox, Margueritte; Schulte, Phillip J.; Zhao, Xin; Hernandez, Adrian F.; Heidenreich, Paul A.; Eapen, Zubin J.; Yancy, Clyde; Bhatt, Deepak L.; Fonarow, Gregg C.

    2015-01-01

    Background Whether heart rate upon discharge following hospitalization for heart failure is associated with long‐term adverse outcomes and whether this association differs between patients with sinus rhythm (SR) and atrial fibrillation (AF) have not been well studied. Methods and Results We conducted a retrospective cohort study from clinical registry data linked to Medicare claims for 46 217 patients participating in Get With The Guidelines®–Heart Failure. Cox proportional‐hazards models were used to estimate the association between discharge heart rate and all‐cause mortality, all‐cause readmission, and the composite outcome of mortality/readmission through 1 year. For SR and AF patients with heart rate ≥75, the association between heart rate and mortality (expressed as hazard ratio [HR] per 10 beats‐per‐minute increment) was significant at 0 to 30 days (SR: HR 1.30, 95% CI 1.22 to 1.39; AF: HR 1.23, 95% CI 1.16 to 1.29) and 31 to 365 days (SR: HR 1.15, 95% CI 1.12 to 1.20; AF: HR 1.05, 95% CI 1.01 to 1.08). Similar associations between heart rate and all‐cause readmission and the composite outcome were obtained for SR and AF patients from 0 to 30 days but only in the composite outcome for SR patients over the longer term. The HR from 0 to 30 days exceeded that from 31 to 365 days for both SR and AF patients. At heart rates heart failure, higher discharge heart rate was associated with increased risks of death and rehospitalization, with higher risk in the first 30 days and for SR compared with AF. PMID:25904590

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

    OpenAIRE

    Wallis, L; Healy, M.; Undy, M; Maconochie, I

    2005-01-01

    Background: Clinical vital signs in children (temperature, heart rate, respiration rate, and blood pressure) are an integral part of clinical assessment of degree of illness or normality. Despite this, only blood pressure and temperature have a reliable evidence base. The accepted ranges of heart and respiration rate vary widely.

  6. Heart rate and activity profile for young female soccer players

    OpenAIRE

    2008-01-01

    The physical and physiological demands of high-level male soccer have been studied extensively, while few studies have investigated the demands placed on females during match-play, however, there is no information available about the heart rate and activity profile of young female soccer players during match play. Therefore, the aim of this study was to examine cardiovascular (heart-rates HR) and physical demands of young female soccer players during a match. Players were observed during a fr...

  7. Accuracy of Heart Rate Watches: Implications for Weight Management.

    Directory of Open Access Journals (Sweden)

    Matthew P Wallen

    Full Text Available Wrist-worn monitors claim to provide accurate measures of heart rate and energy expenditure. People wishing to lose weight use these devices to monitor energy balance, however the accuracy of these devices to measure such parameters has not been established.To determine the accuracy of four wrist-worn devices (Apple Watch, Fitbit Charge HR, Samsung Gear S and Mio Alpha to measure heart rate and energy expenditure at rest and during exercise.Twenty-two healthy volunteers (50% female; aged 24 ± 5.6 years completed ~1-hr protocols involving supine and seated rest, walking and running on a treadmill and cycling on an ergometer. Data from the devices collected during the protocol were compared with reference methods: electrocardiography (heart rate and indirect calorimetry (energy expenditure.None of the devices performed significantly better overall, however heart rate was consistently more accurate than energy expenditure across all four devices. Correlations between the devices and reference methods were moderate to strong for heart rate (0.67-0.95 [0.35 to 0.98] and weak to strong for energy expenditure (0.16-0.86 [-0.25 to 0.95]. All devices underestimated both outcomes compared to reference methods. The percentage error for heart rate was small across the devices (range: 1-9% but greater for energy expenditure (9-43%. Similarly, limits of agreement were considerably narrower for heart rate (ranging from -27.3 to 13.1 bpm than energy expenditure (ranging from -266.7 to 65.7 kcals across devices.These devices accurately measure heart rate. However, estimates of energy expenditure are poor and would have implications for people using these devices for weight loss.

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

    Science.gov (United States)

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

    2009-07-01

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

  9. Metabolism of lipids in experimental hypertrophic hearts of rabbits

    Energy Technology Data Exchange (ETDEWEB)

    Revis, N.W.; Cameron, A.J.V.

    1979-06-01

    Cardiac hypertrophy was induced in rabbits by subcutaneous injection of thyroxine or isoprenaline or by surgically constricting the abdominal aorta. Alterations in lipid metabolism were observed in these hypertrophic hearts. Thyroxine or isoprenaline treatment increased the fatty acids in the serum and stimulated a marked increase in total lipids, triglycerides, and fatty acids in the hypertrophied myocardium. Coarctation of the aorta, in contrast, induced a significant increase in these lipids without significantly affecting serum free fatty acids. Histochemical and morphological studies confirmed an increase in neutral lipids. It is suggested that the observed increase in fatty acids in the heart following thyroxine or isoprenaline treatment is related to the increase in serum free fatty acids, which is followed by an increase in the removal of serum fatty acids by the heart. However, the amount of serum fatty acids that is removed exceeds the amount that is oxidized, which leads to an increase in lipid stores. The increase in lipid stores in the heart following coarctation of the aorta probably corresponds to the decrease in myocardial concentrations of carnitine. Serum lipid levels following coarctation were not significantly different from those of controls.

  10. Probability of detection of clinical seizures using heart rate changes.

    Science.gov (United States)

    Osorio, Ivan; Manly, B F J

    2015-08-01

    Heart rate-based seizure detection is a viable complement or alternative to ECoG/EEG. This study investigates the role of various biological factors on the probability of clinical seizure detection using heart rate. Regression models were applied to 266 clinical seizures recorded from 72 subjects to investigate if factors such as age, gender, years with epilepsy, etiology, seizure site origin, seizure class, and data collection centers, among others, shape the probability of EKG-based seizure detection. Clinical seizure detection probability based on heart rate changes, is significantly (pprobability of detecting clinical seizures (>0.8 in the majority of subjects) using heart rate is highest for complex partial seizures, increases with a patient's years with epilepsy, is lower for females than for males and is unrelated to the side of hemisphere origin. Clinical seizure detection probability using heart rate is multi-factorially dependent and sufficiently high (>0.8) in most cases to be clinically useful. Knowledge of the role that these factors play in shaping said probability will enhance its applicability and usefulness. Heart rate is a reliable and practical signal for extra-cerebral detection of clinical seizures originating from or spreading to central autonomic network structures. Copyright © 2015 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

  11. Inadequate control of heart rate in patients with stable angina: results from the European heart survey.

    NARCIS (Netherlands)

    Daly, C.A.; Clemens, F.; Sendon, J.L.; Tavazzi, L.; Boersma, E.; Danchin, N.; Delahaye, F.; Gitt, A.; Julian, D.; Mulcahy, D.; Ruzyllo, W.; Thygesen, K.; Verheugt, F.W.A.; Fox, K.M.

    2010-01-01

    AIMS: To examine resting heart rate (HR) in a population presenting with stable angina in relation to prior and subsequent pharmacological treatment, comorbid conditions and clinical outcome. METHODS AND RESULTS: The European Heart Survey was a prospective, observational, cohort study of 3779 patien

  12. HEART RATE-LOWERING THERAPY IN THE TREATMENT OF CHRONIC HEART FAILURE

    Directory of Open Access Journals (Sweden)

    S. V. Shalaev

    2015-01-01

    Full Text Available Aspects of heart rate-lowering therapy in patients with chronic heart failure using If-channel blocker ivabradine are discussed. The evidence-based data on ivabradine use reveal its advantages, disadvantages and place in the treatment of cardiac patients.

  13. HEART RATE-LOWERING THERAPY IN THE TREATMENT OF CHRONIC HEART FAILURE

    Directory of Open Access Journals (Sweden)

    S. V. Shalaev

    2015-09-01

    Full Text Available Aspects of heart rate-lowering therapy in patients with chronic heart failure using If-channel blocker ivabradine are discussed. The evidence-based data on ivabradine use reveal its advantages, disadvantages and place in the treatment of cardiac patients.

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

    OpenAIRE

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

    1985-01-01

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

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

    Science.gov (United States)

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

    2013-01-05

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

  16. 1/f scaling in heart rate requires antagonistic autonomic control

    Science.gov (United States)

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

    2004-11-01

    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.

  17. Personality, metabolic rate and aerobic capacity.

    Directory of Open Access Journals (Sweden)

    Antonio Terracciano

    Full Text Available Personality traits and cardiorespiratory fitness in older adults are reliable predictors of health and longevity. We examined the association between personality traits and energy expenditure at rest (basal metabolic rate and during normal and maximal sustained walking. Personality traits and oxygen (VO(2 consumption were assessed in 642 participants from the Baltimore Longitudinal Study of Aging. Results indicate that personality traits were mostly unrelated to resting metabolic rate and energy expenditure at normal walking pace. However, those who scored lower on neuroticism (r = -0.12 and higher on extraversion (r = 0.11, openness (r = 0.13, and conscientiousness (r = 0.09 had significantly higher energy expenditure at peak walking pace. In addition to greater aerobic capacity, individuals with a more resilient personality profile walked faster and were more efficient in that they required less energy per meter walked. The associations between personality and energy expenditure were not moderated by age or sex, but were in part explained by the proportion of fat mass. In conclusion, differences in personality may matter the most during more challenging activities that require cardiorespiratory fitness. These findings suggest potential pathways that link personality to health outcomes, such as obesity and longevity.

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

    OpenAIRE

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

    2014-01-01

    [Purpose] The purpose of this research was to investigate the effects of exercise capacity, heart rate recovery and heart rate variability after high-intensity exercise on caffeine concentration of energy drink. [Methods] The volunteers for this study were 15 male university student. 15 subjects were taken basic physical examinations such as height, weight and BMI before the experiment. Primary tests were examined of VO2max per weight of each subjects by graded exercise test using Bruce proto...

  19. DETECTING CONGESTIVE HEART FAILURE USING HEART RATE SEQUENTIAL TREND ANALYSIS PLOT

    Directory of Open Access Journals (Sweden)

    SRINIVAS KUNTAMALLA,

    2010-12-01

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

  20. Heart rate variability and heart rate turbulence in mild-to-moderate aortic stenosis.

    Science.gov (United States)

    Arslan, Ugur; Ozdemir, Murat; Kocaman, Sinan Altan; Balcioglu, Serhat; Cemri, Mustafa; Cengel, Atiye

    2008-12-01

    To study heart rate (HR) variability and HR turbulence parameters in mild-to-moderate aortic stenosis (AS) and to disclose whether any relationship exists between these parameters and echocardiographic findings. Forty-three asymptomatic patients with mild-to-moderate AS (AS group) were studied. Echocardiographic parameters and HR variability and HR turbulence indices obtained over 24 Holter ECG recordings were compared with those of an age and sex matched control population free of cardiovascular disease. Correlation between echocardiographic findings and HR variability and HR turbulence indices was also studied in the AS group. All HR variability parameters except mean RR interval, RMSSD, and pNN50 and one HR turbulence parameter, turbulence onset, were significantly disturbed in the AS group. Echocardiographic findings of diastolic dysfunction had significant correlations with HR variability and HR turbulence parameters in AS patients. Symphatovagal imbalance as shown by disturbed HR variability and HR turbulence parameters was demonstrated for the first time in patients with mild-to-moderate AS. This imbalance, which was shown to be correlated with echocardiographic findings of diastolic dysfunction, may lead to arrhythmic complications in this seemingly low-risk patient population.

  1. Impact of age and basic heart rate on heart rate turbulence in healthy persons.

    Science.gov (United States)

    Schwab, Jörg Otto; Eichner, Gerrit; Shlevkov, Nikolay; Schrickel, Jan; Yang, Alexander; Balta, Osman; Lewalter, Thorsten; Lüderitz, Berndt

    2005-01-01

    Postextrasystolic acceleration of heart rate (HR), known as HR turbulence (HRT) is attenuated in patients with coronary artery disease at increased risk of adverse events. The influence of age and basic HR on HRT have not been evaluated in a large cohort of persons. In 95 healthy individuals, HRT onset (TO) and slope (TS) were calculated from 24-hour ambulatory electrocardiograms, as well as the turbulence timing (TT). Gender specific differences in TO and TS were compared in simple, linear, weighted regression model. The influence of age and the basic HR preceding ventricular premature contractions on HRT were examined. We found that, in men and women, TO decreases as basic HR increases (P men, TS decreased as basic HR increases, whereas in women, basic HR influenced TS only slightly (P linear regression model revealed a decrease in HRT with increasing age in men. In conclusion, physiological acceleration of the HR within the first 11 beats after premature ventricular complex (VPC) was observed in >75% of healthy individuals. An accelerating HR preceding the VPC influenced HRT in men. An increasing age was associated with a decrease in HRT in men and a decrease in TO in women. These results illustrate the importance of physiological modulations of HRT when used for risk stratification, especially in older populations.

  2. HEART-RATE-VARIABILITY IN LEFT-VENTRICULAR DYSFUNCTION AND HEART-FAILURE - EFFECTS AND IMPLICATIONS OF DRUG-TREATMENT

    NARCIS (Netherlands)

    TUININGA, YS; VANVELDHUISEN, DJ; BROUWER, J; HAAKSMA, J; CRIJNS, HJGM; MANINTVELD, AJ; LIE, KI

    1994-01-01

    Objective-To review the importance of heart rate variability analysis in left ventricular dysfunction and heart failure and to assess the effects of drug treatment. In patients with left: ventricular dysfunction or heart failure, a low heart rate variability is a strong predictor of a low probabilit

  3. Lean heart: Role of leptin in cardiac hypertrophy and metabolism

    Institute of Scientific and Technical Information of China (English)

    Michael; E; Hall; Romain; Harmancey; David; E; Stec

    2015-01-01

    Leptin is an adipokine that has been linked with the cardiovascular complications resulting from obesity such as hypertension and heart disease. Obese patients have high levels of circulating leptin due to increased fat mass. Clinical and population studies have correlated high levels of circulating leptin with the development of cardiac hypertrophy in obesity. Leptin has also been demonstrated to increase the growth of cultured cardiomyocytes. However, several animal studies of obese leptin deficient mice have not supported a role for leptin in promoting cardiac hypertrophy so the role of leptin in this pathological process remains unclear. Leptin is also an important hormone in the regulation of cardiac metabolism where it supports oxidation of glucose and fatty acids. In addition, leptin plays a critical role in protecting the heart from excess lipid accumulation and the formation of toxic lipids in obesity a condition known as cardiac lipotoxicity. This paper focuses on the data supporting and refuting leptin’s role in promoting cardiac hypertrophy as well as its important role in the regulation of cardiac metabolism and protection against cardiac lipotoxicity.

  4. Rethinking cardiac metabolism: metabolic cycles to refuel and rebuild the failing heart.

    Science.gov (United States)

    Taegtmeyer, Heinrich; Lubrano, Genna

    2014-01-01

    The heart is a self-renewing biological pump that converts chemical energy into mechanical energy. The entire process of energy conversion is subject to complex regulation at the transcriptional, translational and post-translational levels. Within this system, energy transfer occurs with high efficiency, facilitated by a series of compound-conserved cycles. At the same time, the constituent myocardial proteins themselves are continuously made and degraded in order to adjust to changes in energy demand and changes in the extracellular environment. We recently have identified signals arising from intermediary metabolism that regulate the cycle of myocardial protein turnover. Using a new conceptual framework, we discuss the principle of metabolic cycles and their importance for refueling and for rebuilding the failing heart.

  5. Heart Rate Variability in Male Sexual Arousal and Erectile Dysfunction

    Science.gov (United States)

    2007-01-22

    Ali Weinstein has provided much assistance with statistics and conceptual ideas. Current and past members of the Sbrocco lab (Laurel Cofell, Andrew ...1995; Stein, Bosner, Kleiger, & Conger , 1994; Task Force, 1996). Time Domain Analyses of HRV There are two methods of time domain analysis (Cohen...Bosner, M. S., Kleiger, R. E., & Conger , B. M. (1994). Heart rate variability: A measure of cardiac autonomic tone. Am Heart J, 127(5), 1376-1381

  6. Quantification of fetal heart rate regularity using symbolic dynamics

    Science.gov (United States)

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

    2007-03-01

    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

  7. Short duration of music modify the heart rate variability

    Directory of Open Access Journals (Sweden)

    Namrata Upadhayay

    2016-10-01

    Full Text Available Background: There are contradictory findings regarding the effect of music on heart rate variability. Reports mention that the music increases the parasympathetic markers of heart rate variability. While some report no change in it. Method: We set out to study the acute effect of music on heart rate variability in 15 healthy male medical students of age 20-36 years. Their resting heart rate variability in eyes closed state for five minutes was recorded thrice: once without listening music, secondly during listening instrumental music for five minutes and thirdly after listening it. Their subjective feeling regarding music and its influence on the brain were documented. Data was compared using the Friedman test followed by Wilcoxon-signed rank test, considering P significant at ≤ 0.05. Results: The mean respiratory rate was significantly higher during music as compared to before listening it. There was a significantly higher HF power after listening to music than during listening it [703.5 (247.25-1195 > 529 (213-699, p=0.026]. As well as, the total power of heart rate variability was significantly higher after music listening as compared to before listening it [2472.5 (1351-4178.75 > 2147.5 (1072.5-3208.25, p=0.035]. All participants felt that they were relaxed during and after the short music session. Conclusions: The instrumental-soft relaxing music for short duration (five minutes can increase the parasympathetic activity of the heart. The effect of music on vagus supply to the heart remains in higher level even after over of music. It makes people feel relaxed and helps to minimize their stress instantly in their working place.

  8. A strong response to selection on mass-independent maximal metabolic rate without a correlated response in basal metabolic rate

    DEFF Research Database (Denmark)

    Wone, B W M; Madsen, Per; Donovan, E R;

    2015-01-01

    Metabolic rates are correlated with many aspects of ecology, but how selection on different aspects of metabolic rates affects their mutual evolution is poorly understood. Using laboratory mice, we artificially selected for high maximal mass-independent metabolic rate (MMR) without direct selecti...

  9. Arterial blood pressure and heart rate regulation in shock state.

    Science.gov (United States)

    DellaVolpe, Jeffrey D; Moore, Jason E; Pinsky, Michael R

    2015-10-01

    Circulatory shock is a complicated problem that carries a high risk of complications and mortality for critically ill patients. The heart rate and blood pressure targets to which a patient in shock should be resuscitated remain a challenge to intensivists. While the ideal blood pressure and heart rate in circulatory shock are still not definitive, recent studies have begun to refine these targets. A recent trial comparing a mean arterial pressure target of 80-85 mmHg with a target of 65-70 mmHg showed no difference in mortality, with a decreased need for renal replacement therapy in patients with pre-existing hypertension based on subgroup analysis. Regulation of heart rate was defined by a trial demonstrating that heart rate control in patients with severe sepsis on high-dose norepinephrine with esmolol titration did not result in additional adverse events. The ideal target blood pressure in the resuscitation of circulatory shock is variable and likely depends on prior blood pressure. Heart rate regulation with β-blockade appears to be safe in selected patients when accompanied by adequate resuscitation and monitoring.

  10. Concurrent validity of the Armour39 heart rate monitor strap.

    Science.gov (United States)

    Flanagan, Shawn D; Comstock, Brett A; Dupont, William H; Sterczala, Adam R; Looney, Dave P; Dombrowski, Dylan H; McDermott, Danielle M; Bryce, Alexander; Maladouangdock, Jesse; Dunn-Lewis, Courtenay; Luk, Hui-Ying; Szivak, Tunde K; Hooper, David R; Kraemer, William J

    2014-03-01

    New technology offers potential advantages in physically demanding environments where convenience and comfort are important and accurate and reliable data collection is challenging. Nevertheless, it is important to validate the accuracy and reliability of such biological monitoring systems (BMS) before they are adopted. The purpose of this investigation was to assess the concurrent validity of a new heart rate monitor across a range of exercise intensities and with a large and diverse group of male subjects in a large cohort with diverse physical fitness characteristics. Seventy-five men (age, 23 ± 4 years; height, 181 ± 8 cm; body mass, 83 ± 12 kg; estimated V[Combining Dot Above]O2peak, 3.16 ± 0.63 [L·min]) volunteered and completed a graded cycle ergometer exercise protocol while heart rate was continuously monitored before, during, and after exercise with the new device (Armour39) and the gold standard (electrocardiogram). The 2-minute stages included sitting, standing, and cycling with 35 W increments until volitional fatigue. The coefficient of determination between mean heart rate values at each stage was R = 0.99, whereas Pearson correlations (r) at each stage were ≥ 0.99. Heart rates during exercise were typically within 1 beat of each other. The Armour39 BMS, therefore, is an acceptable means for the valid and reliable determination of heart rate under various bodily positions and levels of exertion, including maximal exercise intensity.

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

    Science.gov (United States)

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

    2013-01-01

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

  12. Effect of Selective Heart Rate Slowing in Heart Failure With Preserved Ejection Fraction.

    Science.gov (United States)

    Pal, Nikhil; Sivaswamy, Nadiya; Mahmod, Masliza; Yavari, Arash; Rudd, Amelia; Singh, Satnam; Dawson, Dana K; Francis, Jane M; Dwight, Jeremy S; Watkins, Hugh; Neubauer, Stefan; Frenneaux, Michael; Ashrafian, Houman

    2015-11-03

    Heart failure with preserved ejection fraction (HFpEF) is associated with significant morbidity and mortality but is currently refractory to therapy. Despite limited evidence, heart rate reduction has been advocated, on the basis of physiological considerations, as a therapeutic strategy in HFpEF. We tested the hypothesis that heart rate reduction improves exercise capacity in HFpEF. We conducted a randomized, crossover study comparing selective heart rate reduction with the If blocker ivabradine at 7.5 mg twice daily versus placebo for 2 weeks each in 22 symptomatic patients with HFpEF who had objective evidence of exercise limitation (peak oxygen consumption at maximal exercise [o2 peak] change in o2 peak. Secondary outcomes included tissue Doppler-derived E/e' at echocardiography, plasma brain natriuretic peptide, and quality-of-life scores. Ivabradine significantly reduced peak heart rate compared with placebo in the HFpEF (107 versus 129 bpm; Pchange in o2 peak in the HFpEF cohort (-2.1 versus 0.9 mL·kg(-1)·min(-1); P=0.003) and significantly reduced submaximal exercise capacity, as determined by the oxygen uptake efficiency slope. No significant effects on the secondary end points were discernable. Our observations bring into question the value of heart rate reduction with ivabradine for improving symptoms in a HFpEF population characterized by exercise limitation. URL: http://www.clinicaltrials.gov. Unique identifier: NCT02354573. © 2015 The Authors.

  13. Modeling baroreflex regulation of heart rate during orthostatic stress

    DEFF Research Database (Denmark)

    Olufsen, Mette; Tran, Hien T.; Ottesen, Johnny T.

    2006-01-01

    . The model uses blood pressure measured in the finger as an input to model heart rate dynamics in response to changes in baroreceptor nerve firing rate, sympathetic and parasympathetic responses, vestibulo-sympathetic reflex, and concentrations of norepinephrine and acetylcholine. We formulate an inverse...

  14. The Use of Heart Rate Monitors in Physical Education

    Science.gov (United States)

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

    2009-01-01

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

  15. Heart rate-based lactate minimum test: a reproducible method.

    NARCIS (Netherlands)

    Strupler, M.; Muller, G.; Perret, C.

    2009-01-01

    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

  16. Heart rate-based lactate minimum test: a reproducible method.

    NARCIS (Netherlands)

    Strupler, M.; Muller, G.; Perret, C.

    2009-01-01

    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 ai

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

    Science.gov (United States)

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

    2013-01-01

    The aim of the study is to evaluate the use of beta-blockers in chronic heart failure (CHF) and the extent of heart rate reduction achieved in clinical practice and to determine differences in outcome of patients who fulfilled select inclusion criteria of the SHIFT study according to resting heart rate modulated by beta-blocker therapy. We evaluated an all-comer population of our dedicated CHF outpatient clinic between 2006 and 2010. For inclusion, individually optimized doses of guideline-recommended pharmacotherapy including beta-blockers had to be maintained for at least 3 months and routine follow-up performed at our outpatient CHF-clinic thereafter. Treatment dosages of beta-blockers, and demographic and clinical profiles including resting heart rate were assessed. The outcome of patients who fulfilled select inclusion criteria of the SHIFT study (left-ventricular ejection fraction (LVEF) ≤35 %, sinus rhythm, NYHA II-IV) and were followed-up for at least 1 year was stratified according to resting heart rates: ≥75 versus <75 bpm and ≥70 versus <70 bpm. The composite primary endpoint was defined as all-cause death or hospital admission for worsening heart failure during 12-month follow-up. In total, 3,181 patients were assessed in regard to treatment dosages of beta-blockers, and demographic and clinical profiles including resting heart rate. Of the overall studied population, 443 patients fulfilled all inclusion criteria and entered outcome analysis. Median observation time of survivors was 27.5 months with 1,039.7 observation-years in total. Up-titration to at least half the evidence-based target dose of beta-blockers was achieved in 69 % and full up-titration in 29 % of these patients. Patients with increased heart rates were younger, more often male, exhibited a higher NYHA functional class and lower LVEF. The primary endpoint occurred in 21 % of patients in the ≥70 bpm group versus 9 % of patients in the group with heart rates <70

  18. Heart rate and heart rate variability in pregnant dairy cows and their fetuses determined by fetomaternal electrocardiography.

    Science.gov (United States)

    Trenk, Lisa; Kuhl, Juliane; Aurich, Jörg; Aurich, Christine; Nagel, Christina

    2015-11-01

    In this study, fetomaternal electrocardiograms were recorded once weekly in cattle during the last 14 weeks of gestation. From the recorded beat-to-beat (RR) intervals, heart rate and heart rate variability (HRV) variables standard deviation of the RR interval (SDRR) and root mean square of successive RR differences (RMSSD) were calculated. To differentiate between effects of lactation and gestation, pregnant lactating (PL) cows (n = 7) and pregnant nonlactating (PNL) heifers (n = 8) were included. We hypothesized that lactation is associated with stress detectable by HRV analysis. We also followed the hypothesis that heart rate and HRV are influenced by growth and maturation of the fetus toward term. Maternal heart rate changed over time in both groups, and in PL cows, it decreased with drying-off. During the last 5 weeks of gestation, maternal heart rate increased in both groups but was lower in PL cows than in PNL heifers. Maternal HRV did not change over time, but SDRR was significantly higher in PL cows than in PNL heifers, and significant interactions of group × time existed. On the basis of HRV, undisturbed pregnancies are thus no stressor for the dam in cattle. Fetal heart rate decreased from week 14 to week 1 before birth with no difference between groups. Gestational age thus determines heart rate in the bovine fetus. The HRV variables SDRR and RMSSD increased toward the end of gestation in fetuses carried by cows but not in those carried by heifers. The increase in HRV indicates maturation of fetal cardiac regulation which may be overrun by high sympathoadrenal activity in fetuses carried by heifers as suggested by their low HRV.

  19. Fish oil reduces heart rate and oxygen consumption during exercise.

    Science.gov (United States)

    Peoples, Gregory E; McLennan, Peter L; Howe, Peter R C; Groeller, Herbert

    2008-12-01

    Dietary omega-3 polyunsaturated fatty acids (PUFAs) are readily incorporated into heart and skeletal muscle membranes where, in the heart, animal studies show they reduce O2 consumption. To test the hypothesis that omega-3 PUFAs alter O2 efficiency in humans, the effects of fish oil (FO) supplementation on O2 consumption during exercise were evaluated. Sixteen well-trained men (cyclists), randomly assigned to receive 8 x 1 g capsules per day of olive oil (control) or FO for 8 weeks in a double-blind, parallel design, completed the study (control: n = 7, age 27.1 +/- 2.7 years; FO: n = 9, age 23.2 +/- 1.2 years). Subjects used an electronically braked cycle ergometer to complete peak O2 consumption tests (VO 2peak) and sustained submaximal exercise tests at 55% of peak workload (from the VO 2peak test) before and after supplementation. Whole-body O2 consumption and indirect measurements of myocardial O2 consumption [heart rate and rate pressure product (RPP)] were assessed. FO supplementation increased omega-3 PUFA content of erythrocyte cell membranes. There were no differences in VO 2peak (mL kg(-1) min(-1)) (control: pre 66.8 +/- 2.4, post 67.2 +/- 2.3; FO: pre 68.3 +/- 1.4, post 67.2 +/- 1.2) or peak workload after supplementation. The FO supplementation lowered heart rate (including peak heart rate) during incremental workloads to exhaustion (P exercise heart rate, whole-body O2 consumption, and RPP (P heart and skeletal muscle to reduce both whole-body and myocardial O2 demand during exercise, without a decrement in performance.

  20. Rationale and benefits of trimetazidine by acting on cardiac metabolism in heart failure.

    Science.gov (United States)

    Lopatin, Yuri M; Rosano, Giuseppe M C; Fragasso, Gabriele; Lopaschuk, Gary D; Seferovic, Petar M; Gowdak, Luis Henrique W; Vinereanu, Dragos; Hamid, Magdy Abdel; Jourdain, Patrick; Ponikowski, Piotr

    2016-01-15

    Heart failure is a systemic and multiorgan syndrome with metabolic failure as a fundamental mechanism. As a consequence of its impaired metabolism, other processes are activated in the failing heart, further exacerbating the progression of heart failure. Recent evidence suggests that modulating cardiac energy metabolism by reducing fatty acid oxidation and/or increasing glucose oxidation represents a promising approach to the treatment of patients with heart failure. Clinical trials have demonstrated that the adjunct of trimetazidine to the conventional medical therapy improves symptoms, cardiac function and prognosis in patients with heart failure without exerting negative hemodynamic effects. This review focuses on the rationale and clinical benefits of trimetazidine by acting on cardiac metabolism in heart failure, and aims to draw attention to the readiness of this agent to be included in all the major guidelines dealing with heart failure.

  1. Neuroanatomical substrates for the volitional regulation of heart rate

    Directory of Open Access Journals (Sweden)

    Catherine Louise Jones

    2015-03-01

    Full Text Available 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 behaviours. 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, fifteen 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

  2. Heart rate variability predicts the magnitude of heart rate decrease after fingolimod initiation.

    Science.gov (United States)

    Simula, Sakari; Laitinen, Tomi P; Laitinen, Tiina M; Hartikainen, Päivi; Hartikainen, Juha Ek

    2016-11-01

    Fingolimod is an immunomodulator with a disease modifying effect on relapsing-remitting multiple sclerosis (RRMS). A heart rate (HR) decrease shortly after fingolimod initiation, however, requires a clinical vigilance. The aim of this study was to prospectively investigate whether cardiac autonomic regulation can predict the magnitude of HR decrease after fingolimod initiation. Twenty-five patients with RRMS underwent ambulatory 24-h electrocardiogram recording to assess HR variability 20±16 days before fingolimod initiation (baseline) and repeated at the day of fingolimod initiation to assess the magnitude of HR decrease. The percentage of normal RR-intervals with duration more than 50ms different from the previous normal RR-interval (pNN50) was calculated (among the other HR variability parameters) to assess cardiac autonomic regulation. The maximal HR decrease (ΔHR) after the first dose of fingolimod was assessed in absolute units (beats/min) and in percentage (%). The maximal ΔHR was -20±11 beats/min (-23±12%) on the average. pNN50 calculated at baseline correlated with ΔHR% (r=-0.657, pdecrease ≥20% was found in 10/14 patients with pNN50≥10%. The positive and negative predictive values of pNN50≥10% to predict ΔHR≥20% were 83% and 69%, respectively leading to accuracy of 76%. Cardiac autonomic regulation (pNN50>10%) at baseline can be used to predict the magnitude of HR decrease after the first dose of fingolimod. ClinicalTrials.gov (NCT01704183). Copyright © 2016 Elsevier B.V. All rights reserved.

  3. [Metabolic support of the ischemic heart during cardiac surgery].

    Science.gov (United States)

    Luna Ortiz, Pastor; Serrano Valdés, Xenia; Rojas Pérez, Eduardo; de Micheli, Alfredo

    2006-01-01

    We examine [IBM1] the basic principles and clinical results of the metabolic intervention with glucose-insulin-potassium (GIK) solutions in the field of cardiovascular surgery. On the basis of many international publications concerning this subject, and the experience obtained in the operating room of the Instituto Nacional de Cardiologia "Ignacio Chávez", we conclude that the metabolic support wit GIK is a powerful system that provides very useful energy to protect the myocardium during cardiac and non-cardiac surgery. The most recent publications indicate their effects in reducing low output syndromes, due to interventions on the coronary arteries, as well as producing a significant reduction of circulating fatty acids. These effects are produced also in the field of interventional cardiology, where GIK solutions protect the myocardium against damage due to impaired microcirculation. It is evident that these solutions must be utilized in higher concentrations that the initial ones, equal to those employed in laboratory animals. On the other side, it is worthy to remember that it has been always underlined that this treatment represents only a protection for the myocardium. Therefore, its association with other drugs or treatments favoring a good myocardial performance is not contraindicated--on the contrary, it yields better results. The present review presents pharmacological approaches, such as the use of glutamato, aspartate, piruvato, trimetazidina ranolazine and taurine to optimize cardiac energy metabolism, for the management of ischemic heart disease.

  4. Is the normal heart rate "chaotic" due to respiration?

    Science.gov (United States)

    Wessel, Niels; Riedl, Maik; Kurths, Jürgen

    2009-06-01

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

  5. Kramers-Moyal Expansion of Heart Rate Variability

    Science.gov (United States)

    Petelczyc, M.; Żebrowski, J. J.; Baranowski, R.

    2009-05-01

    The first six Kramers-Moyal coefficients were extracted from human heart rate variability recordings. The method requires the determination of the Markov time and of the proper conditional probability densities. We analyzed heart rate data recorded in a group of ten young, healthy subjects. We obtained non-negligible higher order Kramers-Moyal (K-M) terms in 6 h nighttime parts of the 24 h recordings. This indicates that the data is a non-Gaussian process and probably a correlated signal. The analysis yielded important new insights into the character and distribution of the stochastic processes measured in healthy group. In the night hours, the dominant oscillation in the heart rate is the so called respiratory sinus arrhythmia (RSA) -- a physiological phenomenon in which respiration acts as a drive for the heart rate. Certain kinds of pathology may disrupt RSA. We compared nighttime recordings of the healthy group with those recorded in six patients with hypertrophic cardiomyopathy (HCM). HCM is generally a pathology of heart cells but abnormalities in autonomic regulation are also observed. Using the higher order Kramers-Moyal coefficients, we analyzed the skewness and kurtosis in the nighttime recordings for the normal subjects.

  6. Asymmetric acceleration/deceleration dynamics in heart rate variability

    Science.gov (United States)

    Alvarez-Ramirez, J.; Echeverria, J. C.; Meraz, M.; Rodriguez, E.

    2017-08-01

    The heart rate variability (HRV) is an important physiological signal used either to assess the risk of cardiac death or to model the cardiovascular regulatory dynamics. Asymmetries in HRV data have been observed using 2D Poincare plots, which have been linked to a non-equilibrium operation of the cardiac autonomic system. This work further explores the presence of asymmetries but in the serial correlations of the dynamics of HRV data. To this end, detrended fluctuation analysis (DFA) was used to estimate the Hurst exponent both when the heart rate is accelerating and when it is decelerating. The analysis is conducted using data collected from subjects under normal sinus rhythm (NSR), congestive heart failure (CHF) and atrial fibrillation (AF) . For the NSR cases, it was found that correlations are stronger (p heart rate is accelerating than when it is decelerating over different scales in the range 20-40 beats. In contrast, the opposite behavior was detected for the CHF and AF patients. Possible links between asymmetric correlations in the dynamics and the mechanisms controlling the operation of the heart rate are discussed, as well as their implications for modeling the cardiovascular regulatory dynamics.

  7. Postnatal changes in heart mitochondrial calcium and energy metabolism.

    Science.gov (United States)

    Wolf, W J; Rex, K A; Geshi, E; Sordahl, L A

    1991-07-01

    The newborn mammalian heart has less functional capacity compared with the adult, yet newborn myocardial mitochondrial respiratory activity is the same or exceeds that of adult. This study was aimed at determining the temporal changes in newborn rabbit heart mitochondrial energy-linked Ca2+ transport during early postnatal development. At birth, substrate-supported Ca2+ uptake is twice that of adult and declines toward adult rates during the first 14 days. Both NADH- and succinate-linked respiration are equivalent to adult values at birth, increase transiently during the first 7 days, and then decline toward adult. Newborn heart mitochondrial preparations exhibit the same membrane potential (delta psi) values during Ca2+ uptake and have comparable rates of Na(+)-induced Ca2+ efflux as adult. Creatine kinase (CK) activity is very low in 1- to 7-day-old newborn mitochondria and increases rapidly toward adult values after 10 days of age. The decreasing rates of Ca2+ uptake do not appear to be related to respiratory activity, membrane potential, or increased cycling of Ca2+ but rather to a direct effect on the mitochondrial Ca2+ uniporter. Preliminary studies indicate changes in mitochondrial membrane phospholipids during early development that may be related to the increasing CK activity and decreasing Ca2+ uptake and respiration. We postulate that mitochondrial membrane lipid changes in early postnatal development may be the causative factor underlying these changes in functional activity.

  8. QT measurement and heart rate correction during hypoglycemia

    DEFF Research Database (Denmark)

    Christensen, Toke Folke; Randløv, Jette; Christensen, Leif Engmann;

    2010-01-01

    Introduction. Several studies show that hypoglycemia causes QT interval prolongation. The aim of this study was to investigate the effect of QT measurement methodology, heart rate correction, and insulin types during hypoglycemia. Methods. Ten adult subjects with type 1 diabetes had hypoglycemia...... induced by intravenous injection of two insulin types in a cross-over design. QT measurements were done using the slope-intersect (SI) and manual annotation (MA) methods. Heart rate correction was done using Bazett's (QTcB) and Fridericia's (QTcF) formulas. Results. The SI method showed significant...... a significant impact on the prolongation of QT during hypoglycemia. Heart rate correction may also influence the QT during hypoglycemia while the type of insulin is insignificant. Prolongation of QTc in this study did not reach pathologic values suggesting that QTc prolongation cannot fully explain the dead...

  9. Exaggerated heart rate oscillations during two meditation techniques.

    Science.gov (United States)

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

    1999-07-31

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

  10. Effect of oxygen treatment on heart rate after abdominal surgery

    DEFF Research Database (Denmark)

    Rosenberg-Adamsen, S; Lie, C; Bernhard, A;

    1999-01-01

    . METHODS: The authors studied the effect of oxygen therapy on arterial oxygen saturation and heart rate in 100 consecutive unselected patients randomly and double blindly allocated to receive air or oxygen therapy between the first and fourth day after major abdominal surgery. RESULTS: The median arterial...... supplementation were found between patients with or without an epidural catheter or between the postoperative day studied. CONCLUSION: Postoperative oxygen therapy increased arterial oxygen saturation and decreased heart rate after uncomplicated abdominal surgery in a consecutive unselected group of patients who......BACKGROUND: Cardiac complications are common during the postoperative period and may be associated with hypoxemia and tachycardia. Preliminary studies in high-risk patients after operation have shown a possible beneficial effect of oxygen therapy on arterial oxygen saturation and heart rate...

  11. Estimating sleep disordered breathing based on heart rate analysis.

    Science.gov (United States)

    Penzel, Thomas; Glos, Martin; Schobel, Christoph; Lal, Sara; Fietze, Ingo

    2013-01-01

    Heart rate variability and the analysis of the ECG with ECG derived respiration has been used to diagnose sleep disordered breathing. Recently it was possible to distinguish obstructive sleep apnea and central sleep apnea. This can be achieved by analyzing both, heart rate variability and the more mechanically induced ECG derived respiration in parallel. In addition the analysis of cardiopulmonary coupling facilitates to predict the personal risk factor for cardiovascular disorders. The analysis of heart rate, ECG and respiration goes beyond this analysis. Some studies indicate that it is possible to derive sleep stages from these signals. In order to derive sleep stages a more complex analysis of the signals is applied taking into account non-linear properties by using methods of statistical physics. To extract coupling information supports the distinction between sleep stages. Results are reported in this review.

  12. Effect of lung transplantation on heart rate response to exercise.

    Science.gov (United States)

    Armstrong, Hilary F; Gonzalez-Costello, Jose; Thirapatarapong, Wilawan; Jorde, Ulrich P; Bartels, Matthew N

    2015-01-01

    To evaluate if patients have a change in percent of predicted heart rate reserve used at peak exercise (%HRR) after lung transplantation, even at matching workloads. Lung disease of obstructive, restrictive, and mixed types may be associated with an autonomic imbalance. Lung transplantation may improve the effects of pulmonary disease on cardiac function. However, the effect of lung transplantation on heart rate responses during exercise has not been investigated in detail. Retrospective review of patients who underwent lung transplantation. Pre and post transplant cardiopulmonary exercise tests were reviewed. The %HRR significantly improved by a median of 37% (p exercise capacity, percentage of heart rate reserve used improves significantly after lung transplantation, even at matching workloads, indicating a likely improvement in autonomic modulation. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Dopamine and noradrenaline are unrelated to renalase, heart rate, and blood pressure in heart transplant recipients.

    Science.gov (United States)

    Wasilewski, G; Przybyłowski, P; Janik, L; Nowak, E; Sadowski, J; Małyszko, J

    2014-10-01

    Renalase may degrade catecholamines and regulate sympathetic tone and blood pressure. The aim of this study was to assess dopamine, norepinephrine, and renalase in 80 heart transplant recipients and 22 healthy volunteers and their correlations with heart rate, blood pressure control, type of hypotensive therapy, and renal function. Renalase, dopamine, and norepinephrine were studied by using commercially available assays. Renalase levels were higher in heart transplant recipients compared with healthy volunteers, and noradrenaline levels were lower in the studied cohort patients than in the healthy volunteers. Noradrenaline was correlated with white blood cell count (r = -0.21, P blood cell count (r = -0.22, P heart rate, blood pressure, kidney function, or New York Heart Association class. Noradrenaline was significantly higher in patients with elevated diastolic blood pressure (>90 mm Hg) compared with those with normal diastolic blood pressure (P heart transplant patients were related to kidney function but not linked to the sympathetic nervous system activity in this study population. In heart transplant recipients, these findings might suggest that sympathetic denervation and the modulation of β-receptors persist.

  14. Influence of energy drinks and alcohol on post-exercise heart rate recovery and heart rate variability.

    Science.gov (United States)

    Wiklund, Urban; Karlsson, Marcus; Oström, Mats; Messner, Torbjörn

    2009-01-01

    Media have anecdotally reported that drinking energy drinks in combination with alcohol and exercise could cause sudden cardiac death. This study investigated changes in the electrocardiogram (ECG) and heart rate variability after intake of an energy drink, taken in combination with alcohol and exercise. Ten healthy volunteers (five men and five women aged 19-30) performed maximal bicycle ergometer exercise for 30 min after: (i) intake of 0.75 l of an energy drink mixed with alcohol; (ii) intake of energy drink; and, (iii) no intake of any drink. ECG was continuously recorded for analysis of heart rate variability and heart rate recovery. No subject developed any clinically significant arrhythmias. Post-exercise recovery in heart rate and heart rate variability was slower after the subjects consumed energy drink and alcohol before exercise, than after exercise alone. The healthy subjects developed blunted cardiac autonomic modulation after exercising when they had consumed energy drinks mixed with alcohol. Although they did not develop any significant arrhythmia, individuals predisposed to arrhythmia by congenital or other rhythm disorders could have an increased risk for malignant cardiac arrhythmia in similar situations.

  15. Repeated heart rate measurement and cardiovascular outcomes in left ventricular systolic dysfunction.

    Science.gov (United States)

    Hamill, Victoria; Ford, Ian; Fox, Kim; Böhm, Michael; Borer, Jeffrey S; Ferrari, Roberto; Komajda, Michel; Steg, Philippe Gabriel; Tavazzi, Luigi; Tendera, Michal; Swedberg, Karl

    2015-10-01

    Elevated resting heart rate is associated with increased cardiovascular risk, particularly in patients with left ventricular systolic dysfunction. Heart rate is not monitored routinely in these patients. We hypothesized that routine monitoring of heart rate would increase its prognostic value in patients with left ventricular systolic dysfunction. We analyzed the relationship between heart rate measurements and a range of adverse cardiovascular outcomes, including hospitalization for worsening heart failure, in the pooled placebo-treated patients from the morBidity-mortality EvAlUaTion of the If inhibitor ivabradine in patients with coronary disease and left ventricULar dysfunction (BEAUTIFUL) trial and Systolic Heart failure treatment with the If inhibitor ivabradine (SHIFT) Trial, using standard and time-varying covariate Cox proportional hazards models. By adjusting for other prognostic factors, models were fitted for baseline heart rate alone or for time-updated heart rate (latest heart rate) alone or corrected for baseline heart rate or for immediate previous time-updated heart rate. Baseline heart rate was strongly associated with all outcomes apart from hospitalization for myocardial infarction. Time-updated heart rate increased the strengths of associations for all outcomes. Adjustment for baseline heart rate or immediate previous time-updated heart rate modestly reduced the prognostic importance of time-updated heart rate. For hospitalization for worsening heart failure, each 5 beats/min increase in baseline heart rate and time-updated heart rate was associated with a 15% (95% confidence interval, 12-18) and 22% (confidence interval, 19-40) increase in risk, respectively. Even after correction, the prognostic value of time-updated heart rate remained greater. In patients with left ventricular systolic dysfunction, time-updated heart rate is more strongly related with adverse cardiovascular outcomes than baseline heart rate. Heart rate should be measured to

  16. Abnormal heart rate recovery on exercise in ankylosing spondylitis.

    Science.gov (United States)

    Kaya, Mehmet G; Akpek, Mahmut; Lam, Yat-Yin; Dogdu, Orhan; Ardic, Idris; Akgul, Ozgur; Ozgocmen, Salih

    2013-11-05

    This study evaluated the heart rate recovery response in ankylosing spondylitis (AS) patients and control subjects. Delayed heart rate recovery after exercise reflects AD and independently predicts adverse cardiac outcome. Fifty-one patients with AS and 50 age- and matched controls received electrocardiography, echocardiography, and treadmill exercise testing. The heart rate recovery (HRR) index was calculated as the reduction in heart rate from the rate at peak exercise to the rate at the 1st (HRR1), 2nd (HRR2), 3rd (HRR3) and 5th (HRR5) minute after the cessation of exercise stress testing. There were significant differences in HRR1 and HRR2 indices between patients and controls (24.8 ± 12.1 vs 34.9 ± 11.0; pexercise capacity was markedly lower (8.1 ± 2.0 vs 10.5 ± 2.5 METs; p<0.001) in AS than controls. The HRR index is impaired in AS patients, implying the occurrence of autonomic dysfunction even without active joint disease or frank cardiac involvement. © 2013.

  17. Nonlinearity degree of short-term heart rate variability signal

    Institute of Scientific and Technical Information of China (English)

    BIAN Chunhua; NING Xinbao

    2004-01-01

    A nonlinear autoregressive (NAR) model is built to model the heartbeat interval time series and the optimum model degree is proposed to be taken to evaluate the nonlinearity degree of heart rate variability (HRV). A group of healthy persons are studied and the results indicate that this method can effectively get nonlinear information from short (6-7 min) heartbeat series and consequently reflect the degree of heart rate variability, which supplies convenience in clinical application. Finally, a comparison with the traditional time domain method shows that the NAR model method can reflect the complexity of the whole signal and lessen the influence of noise and instability in the signal.

  18. Heart rate recovery in patients with obstructive sleep apnea syndrome

    OpenAIRE

    KARAŞEN, Rıza Murat; ÇİFTÇİ, Bülent; Baran ACAR; YALÇIN, Ahmet Arif; GÜVEN, Selma FIRAT

    2012-01-01

    To demonstrate the effects of obstructive sleep apnea syndrome (OSAS) on baroregulatory function by using heart rate recovery (HRR) parameters. Materials and methods: Fifty-four moderate and severe OSAS patients were included in the study. HRR was defined as the difference in heart rate between peak exercise and 1 min later; a value of 18 beats/min was considered abnormal. OSAS patients were enrolled in the study as group 1 (normal HRR; n = 12) and group 2 (abnormal HRR, n = 42). Left ventr...

  19. Peak heart rate decreases with increasing severity of acute hypoxia

    DEFF Research Database (Denmark)

    Lundby, C; Araoz, M; Van Hall, Gerrit

    2001-01-01

    The purpose of the present study was to investigate the degree to which peak heart rate is reduced during exhaustive exercise in acute hypoxia. Five sea-level lowlanders performed maximal exercise at normobaric normoxia and at three different levels of hypobaric hypoxia (barometric pressures of 518......, 459, and 404 mmHg) in a hypobaric chamber and while breathing 9% O(2) in N(2). These conditions were equivalent to altitudes of 3300, 4300, 5300, and 6300 m above sea level, respectively. At 4300 m, maximal exercise was also repeated after 4 and 8 h. Peak heart rate (HR) decreased from 191 (182...

  20. Heart rate recovery in patients with obstructive sleep apnea syndrome

    OpenAIRE

    KARAŞEN, Rıza Murat; ÇİFTÇİ, Bülent; Acar,Baran; YALÇIN, Ahmet Arif; GÜVEN, Selma FIRAT

    2014-01-01

    To demonstrate the effects of obstructive sleep apnea syndrome (OSAS) on baroregulatory function by using heart rate recovery (HRR) parameters. Materials and methods: Fifty-four moderate and severe OSAS patients were included in the study. HRR was defined as the difference in heart rate between peak exercise and 1 min later; a value of 18 beats/min was considered abnormal. OSAS patients were enrolled in the study as group 1 (normal HRR; n = 12) and group 2 (abnormal HRR, n = 42). Left ventr...

  1. Analysis of Heart Rate Variability Using Time-Varying Filtering of Heart Transplanted Patients

    OpenAIRE

    Laouini, Ghailen; Meste, Olivier; Meo, Marianna

    2012-01-01

    International audience; In this paper, we analyze the heart rate variability (HRV), obtained by using the time-varying integral pulse frequency modulation (TVIPFM) which is well adapted to the exercise stress testing. We consider that the mean heart period is varying function of time, during exercise. This technique allows the estimation of the autonomic nervous system modulation (ANS) from the beat occurrences. The estimated respiratory sinus arrhythmia is then filtered in the time-frequency...

  2. Evaluation of an exercise field test using heart rate monitors to assess cardiorespiratory fitness and heart rate recovery in an asymptomatic population.

    Directory of Open Access Journals (Sweden)

    Crystal L Coolbaugh

    Full Text Available PURPOSE: Measures of cardiorespiratory fitness (CRF and heart rate recovery (HRR can improve risk stratification for cardiovascular disease, but these measurements are rarely made in asymptomatic individuals due to cost. An exercise field test (EFT to assess CRF and HRR would be an inexpensive method for cardiovascular disease risk assessment in large populations. This study assessed 1 the predictive accuracy of a 12-minute run/walk EFT for estimating CRF ([Formula: see text] and 2 the accuracy of HRR measured after an EFT using a heart rate monitor (HRM in an asymptomatic population. METHODS: Fifty subjects (48% women ages 18-45 years completed a symptom-limited exercise tolerance test (ETT (Bruce protocol and an EFT on separate days. During the ETT, [Formula: see text] was measured by a metabolic cart, and heart rate was measured continuously by a HRM and a metabolic cart. RESULTS: EFT distance and sex independently predicted[Formula: see text]. The average absolute difference between observed and predicted [Formula: see text] was 0.26 ± 3.27 ml·kg-1·min-1 for our model compared to 7.55 ± 3.64 ml·kg-1·min-1 for the Cooper model. HRM HRR data were equivalent to respective metabolic cart values during the ETT. HRR at 1 minute post-exercise during ETT compared to the EFT had a moderate correlation (r=0.75, p<0.001. CONCLUSION: A more accurate model to estimate CRF from a 12-minute run/walk EFT was developed, and HRR can be measured using a HRM in an asymptomatic population outside of clinical settings.

  3. Cardiorespiratory fitness and heart rate recovery in obese premenopausal women.

    Science.gov (United States)

    Carroll, S; Marshall, P; Ingle, L; Borkoles, E

    2012-12-01

    Post-exercise heart rate recovery (HRR) has been proposed as a measure of cardiac autonomic dysfunction in apparently healthy adults. We aimed to determine the effects of a lifestyle intervention on HRR among clinically obese premenopausal women. A randomized controlled trial was conducted to investigate the effects of a 3-month non-dieting lifestyle intervention program on cardiorespiratory fitness (CRF) and HRR among healthy clinically obese premenopausal women. Thirty-one were randomly assigned to 3-month intensive lifestyle intervention and 31 served as controls. Sixty-one participants performed a maximal treadmill walking test with metabolic gas exchange. Baseline anthropometric measures were closely related to HRR at 1 min, which may indicate reduced parasympathetic reactivation. Post-exercise HRR at 60 s (HRR60) increased from 21.3 ± 6.2 to 27.8 ± 10.2 bpm in the intervention group compared with a smaller reduction (26.8 ± 12.3 to 24.5 ± 9.9 bpm) in controls (test for interaction P = 0.0001). HRR120 showed a significant effect of time (P = 0.0002) with no significant interaction with lifestyle intervention. A significant increase in VO2 peak was evident in the lifestyle group (21.6 to 23.6 mL/kg/min) compared with a modest reduction in the controls (22.6 to 21.6 mL/kg/min; test for interaction, P = 0.001). Clinically obese healthy premenopausal women achieved significant improvements in HRR60 and VO peak following a 3-month intensive lifestyle intervention. © 2012 John Wiley & Sons A/S.

  4. Metabolic monitoring of the electrically stimulated single heart cell within a microfluidic platform.

    Science.gov (United States)

    Cheng, Wei; Klauke, Norbert; Sedgwick, Helen; Smith, Godfrey L; Cooper, Jonathan M

    2006-11-01

    A device based on five individually addressable microelectrodes, fully integrated within a microfluidic system, has been fabricated to enable the real-time measurement of ionic and metabolic fluxes from electrically active, beating single heart cells. The electrode array comprised one pair of pacing microelectrodes, used for field-stimulation of the cell, and three other microelectrodes, configured as an electrochemical lactate microbiosensor, that were used to measure the amounts of lactate produced by the heart cell. The device also allowed simultaneous in-situ microscopy, enabling optical measurements of cell contractility and fluorescence measurements of extracellular pH and cellular Ca2+. Initial experiments aimed to create a metabolic profile of the beating heart cell, and results show well defined excitation-contraction (EC) coupling at different rates. Ca2+ transients and extracellular pH measurements were obtained from continually paced single myocytes, both as a function of the rate of cell contraction. Finally, the relative amounts of intra- and extra-cellular lactate produced during field stimulation were determined, using cell electroporation where necessary.

  5. Evidence for Intramyocardial Disruption of Lipid Metabolism and Increased Myocardial Ketone Utilization in Advanced Human Heart Failure.

    Science.gov (United States)

    Bedi, Kenneth C; Snyder, Nathaniel W; Brandimarto, Jeffrey; Aziz, Moez; Mesaros, Clementina; Worth, Andrew J; Wang, Linda L; Javaheri, Ali; Blair, Ian A; Margulies, Kenneth B; Rame, J Eduardo

    2016-02-23

    The failing human heart is characterized by metabolic abnormalities, but these defects remains incompletely understood. In animal models of heart failure there is a switch from a predominance of fatty acid utilization to the more oxygen-sparing carbohydrate metabolism. Recent studies have reported decreases in myocardial lipid content, but the inclusion of diabetic and nondiabetic patients obscures the distinction of adaptations to metabolic derangements from adaptations to heart failure per se. We performed both unbiased and targeted myocardial lipid surveys using liquid chromatography-mass spectroscopy in nondiabetic, lean, predominantly nonischemic, advanced heart failure patients at the time of heart transplantation or left ventricular assist device implantation. We identified significantly decreased concentrations of the majority of myocardial lipid intermediates, including long-chain acylcarnitines, the primary subset of energetic lipid substrate for mitochondrial fatty acid oxidation. We report for the first time significantly reduced levels of intermediate and anaplerotic acyl-coenzyme A (CoA) species incorporated into the Krebs cycle, whereas the myocardial concentration of acetyl-CoA was significantly increased in end-stage heart failure. In contrast, we observed an increased abundance of ketogenic β-hydroxybutyryl-CoA, in association with increased myocardial utilization of β-hydroxybutyrate. We observed a significant increase in the expression of the gene encoding succinyl-CoA:3-oxoacid-CoA transferase, the rate-limiting enzyme for myocardial oxidation of β-hydroxybutyrate and acetoacetate. These findings indicate increased ketone utilization in the severely failing human heart independent of diabetes mellitus, and they support the role of ketone bodies as an alternative fuel and myocardial ketone oxidation as a key metabolic adaptation in the failing human heart. © 2016 American Heart Association, Inc.

  6. The effect of relaxing music on heart rate and heart rate variability during ECG GATED-myocardial perfusion scintigraphy.

    Science.gov (United States)

    Tan, Yusuf Ziya; Ozdemir, Semra; Temiz, Ahmet; Celik, Fatmanur

    2015-05-01

    The positive changes in human behavior caused by relaxing music demonstrate the psychological effect of music on human body. A meta-analytical study has shown that relaxing music affects blood pressure and heart rate in coronary heart patients and cancer patients. The aim of our study is to research whether there is a significant effect on heart rate and heart rate variability due to listening to relaxing music during ECG GATED MPS imaging under gamma camera. The music group (n = 50 patients) could choose from 15 different musical types including folk music (no lyric). The other 50 patients were placed in a "no music group" and did not get headphones or any music. There was a statistically significant reduction in the heart rate of patients in the music group compared to those in the control group. Relaxing music provides great benefits to both patient and clinician. There is close relationship between relaxing music and health procedure, can use every area of the health noninvasiv, safe, cheap and is a method don't have side effect. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Impairment of heart rate recovery after peak exercise predicts poor outcome after pediatric heart transplantation.

    Science.gov (United States)

    Giardini, Alessandro; Fenton, Matthew; Derrick, Graham; Burch, Michael

    2013-09-10

    A blunted heart rate recovery (HRR) from peak exercise is associated with adverse outcome in adults with ischemic heart disease. We assessed HRR after pediatric heart transplantation (HTx) and its prognostic use. Between 2004 and 2010 we performed 360 maximal exercise tests (median, 2 tests/patient; range, 1-7) in 128 children (66 men; age at test, 14 ± 3 years) who received HTx (age, 8.5 ± 5.1 years) because of cardiomyopathy (66%) or congenital heart defects (34%). The change in heart rate from peak exercise to 1 minute of recovery was measured as HRR and was expressed as Z score calculated from reference data obtained in 160 healthy children. HRR was impaired soon after HTx (average in first 2 years Z=-1.9 ± 3.5) but improved afterward (Z=+0.52/y), such that HRR Z score normalized in most patients by 6 years after HTx (average, 0.6 ± 1.8). A subsequent decline in HRR Z score was noted from 6 years after HTx (rate of Z=-0.11/y). After 27 ± 15 months from the most recent exercise test, 19 patients died or were re-heart transplantation. For the follow-up after 6 years, HRR Z score was the only predictor of death/re-heart transplantation (P=0.003). Patients in the lowest quartile of HRR Z score had a much higher 5-year event rate (event-free rate, 29% versus 84%; hazard ratio, 7.0; P=0.0013). HRR is blunted soon after HTx but normalizes at ≈ 6 years, potentially as a result of parasympathetic reinnervation of the graft, but then declines. This late decline in HRR Z score is associated with worse outcome.

  8. Acetylation control of cardiac fatty acid β-oxidation and energy metabolism in obesity, diabetes, and heart failure.

    Science.gov (United States)

    Fukushima, Arata; Lopaschuk, Gary D

    2016-12-01

    Alterations in cardiac energy metabolism are an important contributor to the cardiac pathology associated with obesity, diabetes, and heart failure. High rates of fatty acid β-oxidation with cardiac insulin resistance represent a cardiac metabolic hallmark of diabetes and obesity, while a marginal decrease in fatty acid oxidation and a prominent decrease in insulin-stimulated glucose oxidation are commonly seen in the early stages of heart failure. Alterations in post-translational control of energy metabolic processes have recently been identified as an important contributor to these metabolic changes. In particular, lysine acetylation of non-histone proteins, which controls a diverse family of mitochondrial metabolic pathways, contributes to the cardiac energy derangements seen in obesity, diabetes, and heart failure. Lysine acetylation is controlled both via acetyltransferases and deacetylases (sirtuins), as well as by non-enzymatic lysine acetylation due to increased acetyl CoA pool size or dysregulated nicotinamide adenine dinucleotide (NAD(+)) metabolism (which stimulates sirtuin activity). One of the important mitochondrial acetylation targets are the fatty acid β-oxidation enzymes, which contributes to alterations in cardiac substrate preference during the course of obesity, diabetes, and heart failure, and can ultimately lead to cardiac dysfunction in these disease states. This review will summarize the role of lysine acetylation and its regulatory control in the context of mitochondrial fatty acid β-oxidation. The functional contribution of cardiac protein lysine acetylation to the shift in cardiac energy substrate preference that occurs in obesity, diabetes, and especially in the early stages of heart failure will also be reviewed. This article is part of a Special Issue entitled: The role of post-translational protein modifications on heart and vascular metabolism edited by Jason R.B. Dyck & Jan F.C. Glatz.

  9. Remote measurements of heart and respiration rates for telemedicine.

    Directory of Open Access Journals (Sweden)

    Fang Zhao

    Full Text Available 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.

  10. Remote measurements of heart and respiration rates for telemedicine.

    Science.gov (United States)

    Zhao, Fang; Li, Meng; Qian, Yi; Tsien, Joe Z

    2013-01-01

    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.

  11. [Bundle-branch block depending on the heart rate].

    Science.gov (United States)

    Apostolov, L

    1975-01-01

    Five patients are reported, admitted to the hospital, with diseases predominantly of the cardio-vascular system. During the electrocardiographic examinations bundle branch block was established, depending on heart rate. It fluctuated within the physiological limits from 50 to 90/min. In three of the patients, the bundle branch block appeared with the quickening of the heart rate (tachycardia-depending bundle branch block) and in two of the patients--the bundle branch block appeared during the slowing down of the heart action and disappeared with its quickening (bradicardia-depending bundle branch block). A brief literature review is presented and attention is paid to the possible diagnostic errors and the treatment mode of those patients with cardiac tonic and antiarrhythmic medicaments.

  12. The Effect of Bicycle Ergometer Exercise at Varying Intensities on the Heart Rate, EMG and Mood State Responses to a Mental Arithmetic Stressor.

    Science.gov (United States)

    McGowan, Colleen R.; And Others

    1985-01-01

    This study examined the effect of bicycle ergometer exercise at varying metabolic intensities upon the heart rate, electromyographic (EMG), and mood state responses to a timed mental arithmetric stressor of 12 adult males. Exercise influenced heart rate and EMG but not physiological and psychological responses to the arithmetic stressor.…

  13. Inhalation of ultrafine carbon particles alters heart rate and heart rate variability in people with type 2 diabetes.

    Science.gov (United States)

    Vora, Rathin; Zareba, Wojciech; Utell, Mark J; Pietropaoli, Anthony P; Chalupa, David; Little, Erika L; Oakes, David; Bausch, Jan; Wiltshire, Jelani; Frampton, Mark W

    2014-07-16

    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. 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. 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. 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.

  14. Metabolism and aging: effects of cold exposure on metabolic rate, body composition, and longevity in mice.

    Science.gov (United States)

    Vaanholt, Lobke M; Daan, Serge; Schubert, Kristin A; Visser, G Henk

    2009-01-01

    "metabolic" organ mass (i.e., heart, liver, kidneys, and brain). No matter how it was expressed, LEP in CC mice significantly exceeded that of WW mice. This result demonstrates that increased energy expenditure does not shorten life span and adds evidence to the intraspecific refutation of the rate-of-living theory. We suggest that increased energy expenditure has both positive and negative effects on different factors determining life span and that the relationship between energy turnover and longevity is fundamentally nonmonotonic.

  15. Good and bad consequences of altered fatty acid metabolism in heart failure: evidence from mouse models.

    Science.gov (United States)

    Abdurrachim, Desiree; Luiken, Joost J F P; Nicolay, Klaas; Glatz, Jan F C; Prompers, Jeanine J; Nabben, Miranda

    2015-05-01

    The shift in substrate preference away from fatty acid oxidation (FAO) towards increased glucose utilization in heart failure has long been interpreted as an oxygen-sparing mechanism. Inhibition of FAO has therefore evolved as an accepted approach to treat heart failure. However, recent data indicate that increased reliance on glucose might be detrimental rather than beneficial for the failing heart. This review discusses new insights into metabolic adaptations in heart failure. A particular focus lies on data obtained from mouse models with modulations of cardiac FA metabolism at different levels of the FA metabolic pathway and how these differently affect cardiac function. Based on studies in which these mouse models were exposed to ischaemic and non-ischaemic heart failure, we discuss whether and when modulations in FA metabolism are protective against heart failure.

  16. Leptin Expression Affects Metabolic Rate in Zebrafish Embryos (D. rerio

    Directory of Open Access Journals (Sweden)

    Mark R Dalman

    2013-07-01

    Full Text Available We used antisense morpholino oligonucleotide technology to knockdown leptin-(A gene expression in developing zebrafish embryos and measured its effects on metabolic rate and cardiovascular function. Using two indicators of metabolic rate, oxygen consumption was significantly lower in leptin morphants early in development (<48 hpf, while acid production was significantly lower in morphants later in development (>48 hpf. Oxygen utilization rates in <48 hpf embryos and acid production in 72 hpf embryos could be rescued to that of wildtype embryos by recombinant leptin coinjected with antisense morpholino. Leptin is established to influence metabolic rate in mammals, and these data suggest leptin signaling also influences metabolic rate in fishes.

  17. Role of feedback in voluntary control of heart rate.

    Science.gov (United States)

    Manuck, S B; Levenson, R W; Hinrichsen, J J; Gryll, S L

    1975-06-01

    The relative effectiveness of biofeedback techniques on the voluntary control of heart rate was examined by randomly assigning 32 Ss to one of four feedback conditions in a bi-directional heart-rate control task: (1) no feedback, (2) binary feedback--S was signaled when an interbeat interval had changed in the correct direction, (3) "real-time," proportional feedback--S was provided information about the relative duration of successive interbeat intervals, and (4) numerical, proportional feedback--each interbeat interval was represented as a numeral indicating its relationship to pre-trial mean by direction and magnitude. Significant over-all heart-rate changes were evidenced for both increase and decrease directions, but no differences were found between the feedback conditions. While these data suggest that feedback may be a relatively insignificant factor in voluntary heart-rate control, it was recommended that further investigation examine the role of feedback within the context of other training, mediating and motivational variables.

  18. Heart Rate Variability and Drawing Impairment in Hypoxemic COPD

    Science.gov (United States)

    Incalzi, Raffaele Antonelli; Corsonello, Andrea; Trojano, Luigi; Pedone, Claudio; Acanfora, Domenico; Spada, Aldo; D'Addio, Gianni; Maestri, Roberto; Rengo, Franco; Rengo, Giuseppe

    2009-01-01

    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…

  19. Exercise training and heart rate variability in older people

    NARCIS (Netherlands)

    Schuit, A.J.; Amelsvoort, van L.G.P.M.; Verheij, T.C.; Rijneke, R.D.; Maan, A.C.; Swenne, C.A.; Schouten, E.G.

    1999-01-01

    Purpose: Heart rate variability (HRV), a characteristic that is potentially increased by physical activity, has been associated with incidence of cardiac events and total mortality. Since the incidence of cardiac events among older people is high and their physical activity levels and HRV are

  20. Heart Rate Variability Interventions for Concussion and Rehabilitation

    Directory of Open Access Journals (Sweden)

    Robert Lake Conder

    2014-08-01

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

  1. Gonadal hormones and heart rate as an emotional response

    NARCIS (Netherlands)

    de Loos, Wolter Statius

    1988-01-01

    Animai experiments may give information on the physiology of hormones under stress conditions. The model for the investigation of acute emotional stress in animals that has been chosen permits the study of heart rate in freely moving laboratory rats as a sensitive psychophysiological parameter, This

  2. Transfer entropy analysis of maternal and fetal heart rate coupling.

    Science.gov (United States)

    Marzbanrad, Faezeh; Kimura, Yoshitaka; Endo, Miyuki; Palaniswami, Marimuthu; Khandoker, Ahsan H

    2015-01-01

    Although evidence of the short term relationship between maternal and fetal heart rates has been found in previous model-based studies, knowledge about the mechanism and patterns of the coupling during gestation is still limited. In this study, a model-free method based on Transfer Entropy (TE) was applied to quantify the maternal-fetal heart rate couplings in both directions. Furthermore, analysis of the lag at which TE was maximum and its changes throughout gestation, provided more information about the mechanism of coupling and its latency. Experimental results based on fetal electrocardiograms (fECGs) and maternal ECG showed the evidence of coupling for 62 out of 65 healthy mothers and fetuses in each direction, by statistically validating against the surrogate pairs. The fetuses were divided into three gestational age groups: early (16-25 weeks), mid (26-31 weeks) and late (32-41 weeks) gestation. The maximum TE from maternal to fetal heart rate significantly increased from early to mid gestation, while the coupling delay on both directions decreased significantly from mid to late gestation. These changes occur concomitant with the maturation of the fetal sensory and autonomic nervous systems with advancing gestational age. In conclusion, the application of TE with delays revealed detailed information about the changes in fetal-maternal heart rate coupling strength and latency throughout gestation, which could provide novel clinical markers of fetal development and well-being.

  3. Exercise blood pressure and heart rate reference values.

    Science.gov (United States)

    Gläser, Sven; Friedrich, Nele; Koch, Beate; Schäper, Christoph; Völzke, Henry; Felix, Stephan B; Empen, Klaus; Hannemann, Anke; Ewert, Ralf; Dörr, Marcus

    2013-08-01

    Besides their prognostic impact blood pressure and peak heart rate are widely used endpoint parameters for incremental exercise tests. Reference equations and ranges on both are sparse. This study aims to describe prediction equations and reference ranges for systolic and diastolic blood pressure as well as for peak heart rate assessed during a symptom limited incremental exercise test based on a population based study--the Study of Health in Pomerania. For this purpose, 1708 individuals aged 25-85 years underwent cardiopulmonary exercise testing. After exclusion of subjects with cardiopulmonary diseases and antihypertensive medications regression analyses revealed age, sex and body mass index as statistically significant interfering factors. In accordance, prediction equations and reference ranges for blood pressure and peak heart rate with respect to sex, age and BMI have been established. This study provides a reliable set of prediction equations for blood pressure and heart rate values at peak exercise, assessed in a general population over a wide age range. Copyright © 2013 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.

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

    Science.gov (United States)

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

    2012-01-01

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

  5. Heart rate variability and sustained attention in ADHD children

    NARCIS (Netherlands)

    Börger, N.A.; Van der Meere, J.J.; Ronner, A.; Alberts, E.; Geuze, R.H.; Bogte, H

    The major goal of the current study was to investigate the association between continuous performance tests (CPTs) and the heart rate variability (HRV) of attention deficit hyperactivity disorder (ADHD) children. The HRV, specifically the 0.10-Hz component, may be considered to be a

  6. Noradrenaline: Central inhibitory control of blood pressure and heart rate

    NARCIS (Netherlands)

    Jong, Wybren de

    Noradrenaline injected bilaterally into the brainstem in the area of the nucleus tractus solitarii decreased systemic arterial blood pressure and heart rate of anesthetized rats. The effect of noradrenaline was prevented by a preceding injection of the α-adrenergic blocking agent phentolamine, at

  7. Individual variability in heart rate recovery after standardized submaximal exercise

    NARCIS (Netherlands)

    M.S. Brink; C. Visscher; Koen A.P.M. Lemmink; H.T.D. van der Does

    2012-01-01

    To optimize performance, coaches and athletes are always looking for the right balance between training load and recovery. Therefore, closely monitoring of athletes is important. Heart rate recovery (HRR) after standardized sub maximal exercise has been proposed as a useful variable to monitor

  8. Relationship between Exercise Heart Rate and Music Tempo Preference

    Science.gov (United States)

    Karageorghis, Costas I.; Jones, Leighton; Low, Daniel C.

    2006-01-01

    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 =…

  9. Volitional Control of Heart Rate During Exercise Stress.

    Science.gov (United States)

    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…

  10. Simplifying cardiovascular risk estimation using resting heart rate.

    LENUS (Irish Health Repository)

    Cooney, Marie Therese

    2010-09-01

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

  11. Heart rate variability is reduced during acute uncomplicated diverticulitis

    DEFF Research Database (Denmark)

    Huang, Chenxi; Alamili, Mahdi; Rosenberg, Jacob

    2016-01-01

    BACKGROUND: The aim of the present study was to report the trajectory of heart rate variability (HRV) indices during a low-grade acute inflammation and their associations to biomarkers for infection. METHODS: Twelve patients with uncomplicated acute diverticulitis completed this observational study...

  12. Muscle metaboreflex and autonomic regulation of heart rate in humans

    DEFF Research Database (Denmark)

    Fisher, James P; Adlan, Ahmed M; Shantsila, Alena

    2013-01-01

    We elucidated the autonomic mechanisms whereby heart rate (HR) is regulated by the muscle metaboreflex. Eight male participants (22 ± 3 years) performed three exercise protocols: (1) enhanced metaboreflex activation with partial flow restriction (bi-lateral thigh cuff inflation) during leg cycling...

  13. Exploring the Relationship between Fetal Heart Rate and Cognition

    Science.gov (United States)

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

    2010-01-01

    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…

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

    Science.gov (United States)

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

    2012-01-01

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

  15. Decreased heart rate variability responses during early postoperative mobilization

    DEFF Research Database (Denmark)

    Jans, Øivind; Brinth, Louise; Kehlet, Henrik

    2015-01-01

    to postoperative autonomic dysfunction. Thus, based on a previous study on haemodynamic responses during mobilization before and after elective total hip arthroplasty (THA), we performed secondary analyses of heart rate variability (HRV) and aimed to identify possible abnormal postoperative autonomic responses...

  16. Individual variability in heart rate recovery after standardized submaximal exercise

    NARCIS (Netherlands)

    Does, H.T.D. van der; Brink, M.S.; Visscher, C.; Lemmink, K.A.P.M.

    2012-01-01

    To optimize performance, coaches and athletes are always looking for the right balance between training load and recovery. Therefore, closely monitoring of athletes is important. Heart rate recovery (HRR) after standardized sub maximal exercise has been proposed as a useful variable to monitor (Lamb

  17. Fetal heart rate changes associated with general anesthesia.

    Science.gov (United States)

    Fedorkow, D M; Stewart, T J; Parboosingh, J

    1989-07-01

    Decreased fetal heart rate variability was noted 90 seconds after the induction of general anesthesia with sodium thiopentone and fentanyl in a patient undergoing basket extraction of a renal calculus at 30 weeks' gestation. The fetal sleep pattern lasted for 105 minutes after the anesthetic was discontinued, 45 minutes after the mother was fully awake.

  18. Noradrenaline: Central inhibitory control of blood pressure and heart rate

    NARCIS (Netherlands)

    Jong, Wybren de

    1974-01-01

    Noradrenaline injected bilaterally into the brainstem in the area of the nucleus tractus solitarii decreased systemic arterial blood pressure and heart rate of anesthetized rats. The effect of noradrenaline was prevented by a preceding injection of the α-adrenergic blocking agent phentolamine, at th

  19. Gonadal hormones and heart rate as an emotional response

    NARCIS (Netherlands)

    de Loos, Wolter Statius

    1988-01-01

    Animai experiments may give information on the physiology of hormones under stress conditions. The model for the investigation of acute emotional stress in animals that has been chosen permits the study of heart rate in freely moving laboratory rats as a sensitive psychophysiological parameter, This

  20. Decreased heart rate variability in surgeons during night shifts

    DEFF Research Database (Denmark)

    Amirian, Ilda; Toftegård Andersen, Lærke; Rosenberg, Jacob

    2014-01-01

    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'...

  1. Relationship between SCR, heart rate and information processing.

    NARCIS (Netherlands)

    Swart, de J.H.; Das-Smaal, E.A.

    1976-01-01

    This study was designed to investigate the relationship between the amount of information processing in concept learning (CL) and autonomic physiological activity as measured by skin conductance response (SCR). Heart rate (HR) was also measured. Two conceptual rules were used: a conjunctive and an i

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

    Science.gov (United States)

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

    2014-01-01

    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.

  3. Daily stride rate activity and heart rate response in children with cerebral palsy.

    Science.gov (United States)

    Balemans, Astrid C J; van Wely, Leontien; Middelweerd, Anouk; van den Noort, Josien C; Becher, Jules G; Dallmeijer, Annet J

    2014-01-01

    To compare daily stride rate activity, daily exercise intensity, and heart rate intensity of stride rate in children with cerebral palsy with that of typically developing children. Forty-three children with cerebral palsy, walking without (Gross Motor Function Classification System (GMFCS) I and II) or with (GMFCS III) an aid and 27 typically developing children (age range 7-14 years) wore a StepWatch™ activity monitor and a heart rate monitor. Time spent and mean heart rate reserve at each stride rate activity level and time spent in each mean heart rate reserve zone was compared. Daily stride rate activity was lower in children with cerebral palsy (39%, 49% and 79% in GMFCS I, II and III, respectively) compared with typically developing children (p cerebral palsy who are walking without aids, similar to that of typically developing, whereas children with cerebral palsy using walking aids show higher effort of walking. Despite a lower stride rate activity in cerebral palsy, daily exercise intensity seems comparable, indicating that the StepWatch™ monitor and the heart rate monitor measure different aspects of physical activity.

  4. Lower sedentary metabolic rate in women compared with men.

    OpenAIRE

    Ferraro, R.; Lillioja, S; Fontvieille, A M; Rising, R; Bogardus, C; Ravussin, E

    1992-01-01

    Since females have a greater prevalence of obesity compared with males, the question arises whether females have lower metabolic rate than males after adjusting for differences in body weight and composition. 24-h energy expenditure (24EE), basal metabolic rate (BMR), and sleeping metabolic rate (SMR) were measured in a respiratory chamber in 235 healthy, nondiabetic Caucasian subjects (114 males, 121 females). Body composition was determined by hydrodensitometry. 24EE was 124 +/- 38 kcal/d (...

  5. Omega-3 Polyunsaturated Fatty Acids and Heart Rate Variability

    OpenAIRE

    Jeppe Hagstrup Christensen

    2011-01-01

    Omega-3 polyunsaturated fatty acids (PUFA) may modulate autonomic control of the heart because omega-3 PUFA is abundant in the brain and other nervous tissue as well as in cardiac tissue. This might partly explain why omega-3 PUFA offer some protection against sudden cardiac death (SCD). The autonomic nervous system is involved in the pathogenesis of SCD. Heart rate variability (HRV) can be used as a non-invasive marker of cardiac autonomic control and a low HRV is a predictor for SCD and arr...

  6. The Scaling of Maximum and Basal Metabolic Rates of Mammals and Birds

    CERN Document Server

    Barbosa, L A; Silva, J K L; Barbosa, Lauro A.; Garcia, Guilherme J. M.; Silva, Jafferson K. L. da

    2004-01-01

    Allometric scaling is one of the most pervasive laws in biology. Its origin, however, is still a matter of dispute. Recent studies have established that maximum metabolic rate scales with an exponent larger than that found for basal metabolism. This unpredicted result sets a challenge that can decide which of the concurrent hypotheses is the correct theory. Here we show that both scaling laws can be deduced from a single network model. Besides the 3/4-law for basal metabolism, the model predicts that maximum metabolic rate scales as $M^{6/7}$, maximum heart rate as $M^{-1/7}$, and muscular capillary density as $M^{-1/7}$, in agreement with data.

  7. Music structure determines heart rate variability of singers

    Science.gov (United States)

    Vickhoff, Björn; Malmgren, Helge; Åström, Rickard; Nyberg, Gunnar; Ekström, Seth-Reino; Engwall, Mathias; Snygg, Johan; Nilsson, Michael; Jörnsten, Rebecka

    2013-01-01

    Choir singing is known to promote wellbeing. One reason for this may be that singing demands a slower than normal respiration, which may in turn affect heart activity. Coupling of heart rate variability (HRV) to respiration is called Respiratory sinus arrhythmia (RSA). This coupling has a subjective as well as a biologically soothing effect, and it is beneficial for cardiovascular function. RSA is seen to be more marked during slow-paced breathing and at lower respiration rates (0.1 Hz and below). In this study, we investigate how singing, which is a form of guided breathing, affects HRV and RSA. The study comprises a group of healthy 18 year olds of mixed gender. The subjects are asked to; (1) hum a single tone and breathe whenever they need to; (2) sing a hymn with free, unguided breathing; and (3) sing a slow mantra and breathe solely between phrases. Heart rate (HR) is measured continuously during the study. The study design makes it possible to compare above three levels of song structure. In a separate case study, we examine five individuals performing singing tasks (1–3). We collect data with more advanced equipment, simultaneously recording HR, respiration, skin conductance and finger temperature. We show how song structure, respiration and HR are connected. Unison singing of regular song structures makes the hearts of the singers accelerate and decelerate simultaneously. Implications concerning the effect on wellbeing and health are discussed as well as the question how this inner entrainment may affect perception and behavior. PMID:23847555

  8. Heart rate variability in neonates of type 1 diabetic pregnancy.

    Science.gov (United States)

    Russell, Noirin E; Higgins, Mary F; Kinsley, Brendan F; Foley, Michael E; McAuliffe, Fionnuala M

    2016-01-01

    Cardiomyopathy is a common finding in offspring of pre-gestational type 1 diabetic pregnancy. Echocardiographic and biochemical evidence of fetal cardiac dysfunction have also been reported. Studies suggest that offspring of diabetic mothers (ODM) undergo a fetal programming effect due to the hyperglycaemic intrauterine milieu which increases their risk of cardiovascular morbidity in adult life. Decreased neonatal heart rate variability (HRV) has been described in association with in-utero growth restriction, prematurity, sudden infant death syndrome and congenital heart disease. The effect of in-utero exposure to hyperglycaemia in diabetic pregnancy on neonatal HRV is unknown. Our aim was to determine if neonatal HRV differs between normal and diabetic pregnancy. This was a prospective observational study of 38 patients with pregestational type 1 diabetes and 26 controls. HRV assessment was performed using Powerlab (ADI Instruments Ltd). Heart rate variability assessment and cord blood sampling for pH and glucose were performed for all neonates. Maternal glycaemic control was assessed via measurement of glycosylated haemoglobin in each trimester in the diabetic cohort. Neonates of diabetic mothers had evidence of altered heart rate variability, with increased low frequency to high frequency ratio (LF: HF), suggestive of a shift towards sympathetic predominance (pheart to fluctuations in maternal glycaemia with subsequent alterations in HRV may explain why infants of diabetic mothers are at greater risk of cardiovascular disease in later life. Copyright © 2015. Published by Elsevier Ireland Ltd.

  9. Resting Heart Rate and Long-Term Outcomes Among African Americans: Insights From the Jackson Heart Study

    Science.gov (United States)

    Parikh, Kishan S.; Greiner, Melissa A.; Suzuki, Takeki; DeVore, Adam D.; Blackshear, Chad; Maher, Joseph F.; Curtis, Lesley H.; Hernandez, Adrian F.; O’Brien, Emily C.; Mentz, Robert J.

    2016-01-01

    Importance Increased resting heart rate is associated with worse outcomes in studies of mostly white populations, but its significance is not well established in African Americans whose cardiac comorbidities and structural abnormalities differ. Objective We studied the prognostic utility of heart rate in a community-based African American cohort in Jackson, Mississippi. Design We included 5261 participants in the Jackson Heart Study. Baseline heart rate was assessed by quintiles and as a continuous variable. Study follow-up was greater than 7 years and started in 2000. Setting The Jackson Heart Study, a prospective, community-based study in Jackson, Mississippi. Participants All participants with baseline heart rate documented by 12-lead electrocardiogram without pacing or atrial fibrillation on their baseline Jackson Heart Study exam were included in our study. Main Outcomes and Measures We estimated unadjusted and adjusted associations between heart rate and all-cause mortality and heart failure hospitalization using Cox proportional hazards models. Results Median baseline heart rate was 63 bpm (interquartile range, 57–71 bpm). The highest heart rate quintile (73–118 bpm) included more women, higher rates of diabetes and hypertension, higher body mass index, less average activity, and lower β-blocker use compared with lower quintiles. Caffeine intake and ejection fraction were similar between groups. As a continuous variable, elevated heart rate was associated with increased mortality and heart failure hospitalizations with adjusted hazard ratios for every 5 bpm increase of 1.14 (95% CI, 1.10–1.19) and 1.10 (95% CI, 1.05–1.16), respectively. Similar patterns were observed in comparisons between highest and lowest quintiles. Conclusions and Relevance Higher baseline heart rate was associated with increased mortality and heart failure hospitalizations among African Americans in the Jackson Heart Study. PMID:27681113

  10. Ultrasound transducer positioning aid for fetal heart rate monitoring.

    Science.gov (United States)

    Hamelmann, Paul; Kolen, Alex; Schmitt, Lars; Vullings, Rik; van Assen, Hans; Mischi, Massimo; Demi, Libertario; van Laar, Judith; Bergmans, Jan

    2016-08-01

    Fetal heart rate (fHR) monitoring is usually performed by Doppler ultrasound (US) techniques. For reliable fHR measurements it is required that the fetal heart is located within the US beam. In clinical practice, clinicians palpate the maternal abdomen to identify the fetal presentation and then the US transducer is fixated on the maternal abdomen where the best fHR signal can be obtained. Finding the optimal transducer position is done by listening to the strength of the Doppler audio output and relying on a signal quality indicator of the cardiotocographic (CTG) measurement system. Due to displacement of the US transducer or displacement of the fetal heart out of the US beam, the fHR signal may be lost. Therefore, it is often necessary that the obstetrician repeats the tedious procedure of US transducer positioning to avoid long periods of fHR signal loss. An intuitive US transducer positioning aid would be highly desirable to increase the work flow for the clinical staff. In this paper, the possibility to determine the fetal heart location with respect to the transducer by exploiting the received signal power in the transducer elements is shown. A commercially available US transducer used for fHR monitoring is connected to an US open platform, which allows individual driving of the elements and raw US data acquisition. Based on the power of the received Doppler signals in the transducer elements, the fetal heart location can be estimated. A beating fetal heart setup was designed and realized for validation. The experimental results show the feasibility of estimating the fetal heart location with the proposed method. This can be used to support clinicians in finding the optimal transducer position for fHR monitoring more easily.

  11. Heart rate variability in infants with West syndrome

    DEFF Research Database (Denmark)

    Møller, Michelle Mai; Høgenhaven, Hans; Uldall, Peter;

    2015-01-01

    with WS the heart rate variability (HRV) was investigated by examining time- and frequency-domain parameters of HRV at the time of the diagnosis of hypsarrhythmia and compared to 22 age-matched controls. For the WS patients the same dataset was obtained and compared again at the end of the study period......PURPOSE: West syndrome (WS) is a severe age-related acute epileptic encephalopathy of infancy characterized by infantile spasms, hypsarrhythmia and psychomotor delay. The aim of this study was to investigate if patients with WS had an altered autonomic output to the heart. METHODS: In 23 patients......-Whitney's U-Test) in the awake state, indicating an abnormal autonomic output to the heart. Comparing the initial to the final examination demonstrated a significant increase in the HRV parameters SDNN (31.3ms) and total power (757ms(2); p=0.001 and p=0.013, Wilcoxon Signed Ranked Test). In addition...

  12. Humoral regulation of heart rate during digestion in pythons (Python molurus and Python regius).

    Science.gov (United States)

    Enok, Sanne; Simonsen, Lasse Stærdal; Pedersen, Signe Vesterskov; Wang, Tobias; Skovgaard, Nini

    2012-05-15

    Pythons exhibit a doubling of heart rate when metabolism increases several times during digestion. Pythons, therefore, represent a promising model organism to study autonomic cardiovascular regulation during the postprandial state, and previous studies show that the postprandial tachycardia is governed by a release of vagal tone as well as a pronounced stimulation from nonadrenergic, noncholinergic (NANC) factors. Here we show that infusion of plasma from digesting donor pythons elicit a marked tachycardia in fasting snakes, demonstrating that the NANC factor resides in the blood. Injections of the gastrin and cholecystokinin receptor antagonist proglumide had no effect on double-blocked heart rate or blood pressure. Histamine has been recognized as a NANC factor in the early postprandial period in pythons, but the mechanism of its release has not been identified. Mast cells represent the largest repository of histamine in vertebrates, and it has been speculated that mast cells release histamine during digestion. Treatment with the mast cell stabilizer cromolyn significantly reduced postprandial heart rate in pythons compared with an untreated group but did not affect double-blocked heart rate. While this study indicates that histamine induces postprandial tachycardia in pythons, its release during digestion is not stimulated by gastrin or cholecystokinin nor is its release from mast cells a stimulant of postprandial tachycardia.

  13. Assessing heart rate variability from real-world Holter reports.

    Science.gov (United States)

    Stein, Phyllis K

    2002-09-01

    Real world clinical Holter reports are often difficult to interpret from a heart rate variability (HRV) perspective. In many cases HRV software is absent. Step-by-step HRV assessment from clinical Holter reports includes: making sure that there is enough usable data, assessing maximum and minimum heart rates, assessing circadian HRV from hourly average heart rates, and assessing HRV from the histogram of R-R intervals and from the plot of R-R intervals or heart rate vs. time. If HRV data are available, time domain HRV is easiest to understand and less sensitive to scanning errors. SDNN (the standard deviation of all N-N intervals in ms) and SDANN (the standard deviation of the 5-min average of N-N intervals in ms) are easily interpreted. SDNN < 70 ms post-MI is a cut point for increased mortality risk. Two times ln SDANN is a good surrogate for ln ultra low frequency power and can be compared with published cut points. SDNNIDX (the average of the standard deviations of N-N intervals for each 5-min in ms) < 30 ms is associated with increased risk in patients with congestive heart failure. RMSSD (the root mean square of successive N-N interval difference in ms) < 17.5 ms has also been associated with increased risk post-myocardial infarction. Frequency domain HRV values are often not comparable to published data. However, graphical power spectral plots can provide additional information about whether the HRV pattern is normal and can also identify some patients with obstructive sleep apnea.

  14. Nonlinear Control of Heart Rate Variability in Human Infants

    Science.gov (United States)

    Sugihara, George; Allan, Walter; Sobel, Daniel; Allan, Kenneth D.

    1996-03-01

    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 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.

  15. Functionality of the baroreceptor nerves in heart rate regulation

    DEFF Research Database (Denmark)

    Ottesen, Johnny T.; Olufsen, Mette

    2011-01-01

    Two models describing the afferent baroreceptor firing are analyzed, a basic model predicting firing using a single nonlinear differential equation, and an extended model, coupling K nonlinear responses. Both models respond to the the rate (derivative) and the rate history of the carotid sinus...... are a consequence of the memory encapsulated by the models, and the nonlinearity gives rise to sigmoidal response curves. The nonlinear afferent baroreceptor models are coupled with an effector model, and the coupled model has been used to predict baroreceptor feedback regulation of heart rate during postural...... change from sitting to standing and during head-up tilt. The efferent model couples the afferent nerve paths to the sympathetic and parasympathetic outflow, and subsequently predicts the build up of an action potential at the sinus knot of the heart. In this paper, we analyze the nonlinear afferent model...

  16. Cardiovascular and metabolic effects of 48-h glucagon-like peptide-1 infusion in compensated chronic patients with heart failure

    DEFF Research Database (Denmark)

    Halbirk, Mads; Nørrelund, Helene; Møller, Niels

    2010-01-01

    )) and placebo infusion. At 0 and 48 h, LVEF, diastolic function, tissue Doppler regional myocardial function, exercise testing, noninvasive cardiac output, and brain natriuretic peptide (BNP) were measured. Blood pressure, heart rate, and metabolic parameters were recorded. Fifteen patients completed...... patients. GLP-1 infusion increased circulating insulin levels and reduced plasma glucose concentration but had no major cardiovascular effects in patients without diabetes but with compensated HF. The impact of minor increases in heart rate and diastolic blood pressure during GLP-1 infusion requires...... effects of 48-h GLP-1 infusions in patients with congestive HF. In a randomized, double-blind crossover design, 20 patients without diabetes and with HF with ischemic heart disease, EF of 30 +/- 2%, New York Heart Association II and III (n = 14 and 6) received 48-h GLP-1 (0.7 pmol.kg(-1).min(-1...

  17. Determination of Fatty Acid Metabolism with Dynamic [11C]Palmitate Positron Emission Tomography of Mouse Heart In Vivo

    Directory of Open Access Journals (Sweden)

    Yinlin Li

    2015-09-01

    Full Text Available The goal of this study was to establish a quantitative method for measuring fatty acid (FA metabolism with partial volume (PV and spill-over (SP corrections using dynamic [11C]palmitate positron emission tomographic (PET images of mouse heart in vivo. Twenty-minute dynamic [11C]palmitate PET scans of four 18- to 20-week-old male C57BL/6 mice under isoflurane anesthesia were performed using a Focus F-120 PET scanner. A model-corrected blood input function, by which the input function with SP and PV corrections and the metabolic rate constants (k1–k5 are simultaneously estimated from the dynamic [11C]palmitate PET images of mouse hearts in a four-compartment tracer kinetic model, was used to determine rates of myocardial fatty acid oxidation (MFAO, myocardial FA esterification, myocardial FA use, and myocardial FA uptake. The MFAO thus measured in C57BL/6 mice was 375.03 ± 43.83 nmol/min/g. This compares well to the MFAO measured in perfused working C57BL/6 mouse hearts ex vivo of about 350 nmol/g/min and 400 nmol/min/g. FA metabolism was measured for the first time in mouse heart in vivo using dynamic [11C]palmitate PET in a four-compartment tracer kinetic model. MFAO obtained with this model was validated by results previously obtained with mouse hearts ex vivo.

  18. General anesthesia suppresses normal heart rate variability in humans

    Science.gov (United States)

    Matchett, Gerald; Wood, Philip

    2014-06-01

    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.

  19. Heart rate control with adrenergic blockade: Clinical outcomes in cardiovascular medicine

    Directory of Open Access Journals (Sweden)

    David Feldman

    2010-05-01

    Full Text Available David Feldman1, Terry S Elton2, Doron M Menachemi3, Randy K Wexler41Heart Failure/Transplant and VAD Programs, Minneapolis Heart Institute, Minneapolis, Minnesota, USA; 2Division of Pharmacology, College of Pharmacology, The Ohio State University, Columbus, Ohio, USA; 3Heart Failure Services, Edith Wolfson Medical Center, The Heart Institute, Sakler School of Medicine, Tel-Aviv University, Holon, Israel; 4Department of Clinical Family Medicine, The Ohio State University, Columbus, Ohio, USAAbstract: The sympathetic nervous system is involved in regulating various cardiovascular parameters including heart rate (HR and HR variability. Aberrant sympathetic nervous system expression may result in elevated HR or decreased HR variability, and both are independent risk factors for development of cardiovascular disease, including heart failure, myocardial infarction, and hypertension. Epidemiologic studies have established that impaired HR control is linked to increased cardiovascular morbidity and mortality. One successful way of decreasing HR and cardiovascular mortality has been by utilizing β-blockers, because their ability to alter cell signaling at the receptor level has been shown to mitigate the pathogenic effects of sympathetic nervous system hyperactivation. Numerous clinical studies have demonstrated that β-blocker-mediated HR control improvements are associated with decreased mortality in postinfarct and heart failure patients. Although improved HR control benefits have yet to be established in hypertension, both traditional and vasodilating β-blockers exert positive HR control effects in this patient population. However, differences exist between traditional and vasodilating β-blockers; the latter reduce peripheral vascular resistance and exert neutral or positive effects on important metabolic parameters. Clinical evidence suggests that attainment of HR control is an important treatment objective for patients with cardiovascular

  20. Impact of Pubertal Development and Physical Activity on Heart Rate Variability in Overweight and Obese Children in Taiwan

    Science.gov (United States)

    Chen, Su-Ru; Chiu, Hung-Wen; Lee, Yann-Jinn; Sheen, Tzong-Chi; Jeng, Chii

    2012-01-01

    Child obesity is frequently associated with dysfunction of autonomic nervous system. Children in pubertal development were suggested to be vulnerable to autonomic nervous system problems such as decrease of heart rate variability from dysregulation of metabolic control. This study explored the influence of pubertal development on autonomic nervous…

  1. Impact of Pubertal Development and Physical Activity on Heart Rate Variability in Overweight and Obese Children in Taiwan

    Science.gov (United States)

    Chen, Su-Ru; Chiu, Hung-Wen; Lee, Yann-Jinn; Sheen, Tzong-Chi; Jeng, Chii

    2012-01-01

    Child obesity is frequently associated with dysfunction of autonomic nervous system. Children in pubertal development were suggested to be vulnerable to autonomic nervous system problems such as decrease of heart rate variability from dysregulation of metabolic control. This study explored the influence of pubertal development on autonomic nervous…

  2. Acute hypoxia increases the cerebral metabolic rate

    DEFF Research Database (Denmark)

    Vestergaard, Mark Bitsch; Lindberg, Ulrich; Aachmann-Andersen, Niels Jacob

    2016-01-01

    The aim of the present study was to examine changes in cerebral metabolism by magnetic resonance imaging of healthy subjects during inhalation of 10% O2 hypoxic air. Hypoxic exposure elevates cerebral perfusion, but its effect on energy metabolism has been less investigated. Magnetic resonance......-acetylaspartate, creatine and phosphocreatine were measured in the visual cortex by magnetic resonance spectroscopy. Twenty-three young healthy males were scanned for 60 min during normoxia, followed by 40 min of breathing hypoxic air. Inhalation of hypoxic air resulted in an increase in cerebral blood flow of 15.5% (p = 0...

  3. Association between oral variables and heart rate variability.

    Science.gov (United States)

    Santana, Milana Drumond Ramos; de Souza, Ana Cecilia Amorim; de Abreu, Luiz Carlos; Valenti, Vitor E

    2013-12-27

    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.

  4. Linear and Nonlinear Heart Rate Variability Indexes in Clinical Practice

    Directory of Open Access Journals (Sweden)

    Buccelletti Francesco

    2012-01-01

    Full Text Available Biological organisms have intrinsic control systems that act in response to internal and external stimuli maintaining homeostasis. Human heart rate is not regular and varies in time and such variability, also known as heart rate variability (HRV, is not random. HRV depends upon organism's physiologic and/or pathologic state. Physicians are always interested in predicting patient's risk of developing major and life-threatening complications. Understanding biological signals behavior helps to characterize patient's state and might represent a step toward a better care. The main advantage of signals such as HRV indexes is that it can be calculated in real time in noninvasive manner, while all current biomarkers used in clinical practice are discrete and imply blood sample analysis. In this paper HRV linear and nonlinear indexes are reviewed and data from real patients are provided to show how these indexes might be used in clinical practice.

  5. Qigong Effects on Heart Rate Variability and Peripheral Vasomotor Responses.

    Science.gov (United States)

    Chang, Mei-Ying

    2015-11-01

    Population aging is occurring worldwide, and preventing cardiovascular event in older people is a unique challenge. The aim of this study was to examine the effects of a 12-week qigong (eight-form moving meditation) training program on the heart rate variability and peripheral vasomotor response of middle-aged and elderly people in the community. This was a quasi-experimental study that included the pre-test, post-test, and nonequivalent control group designs. Seventy-seven participants (experimental group = 47; control group = 30) were recruited. The experimental group performed 30 min of eight-form moving meditation 3 times per week for 12 weeks, and the control group continued their normal daily activities. After 12 weeks, the interaction effects indicated that compared with the control group, the experimental group exhibited significantly improved heart rate variability and peripheral vasomotor responses.

  6. Multifractal heart rate dynamics in human cardiovascular model

    Science.gov (United States)

    Kotani, Kiyoshi; Takamasu, Kiyoshi; Safonov, Leonid; Yamamoto, Yoshiharu

    2003-05-01

    Human cardiovascular and/or cardio-respiratory systems are shown to exhibit both multifractal and synchronous dynamics, and we recently developed a nonlinear, physiologically plausible model for the synchronization between heartbeat and respiration (Kotani, et al. Phys. Rev. E 65: 051923, 2002). By using the same model, we now show the multifractality in the heart rate dynamics. We find that beat-to-beat monofractal noise (fractional Brownian motion) added to the brain stem cardiovascular areas results in significantly broader singularity spectra for heart rate through interactions between sympathetic and parasympathetic nervous systems. We conclude that the model proposed here would be useful in studying the complex cardiovascular and/or cardio- respiratory dynamics in humans.

  7. Low Cost Heart Rate Monitor Using Led-Led Sensor

    Directory of Open Access Journals (Sweden)

    Ahmed Mahrous Ragib

    2009-01-01

    Full Text Available A high sensitivity, low power and low cost sensor has been developed for photoplethysmography (PPG measurement. The PPG principle was applied to follow the dilatation and contraction of skin blood vessels during the cardiac cycle. A standard light emitting diodes (LEDs has been used as a light emitter and detector, and in order to reduce the space, cost and power, the classical analogue-to-digital converters (ADCs replaced by the pulse-based signal conversion techniques. A general purpose microcontroller has been used for the implementation of measurement protocol. The proposed approach leads to better spectral sensitivity, increased resolution, reduction in cost, dimensions and power consumption. The basic sensing configuration presented is capable of detecting the PPG signal from a finger or toe, and it is very simple to extract the heart rate and heart rate variability from such a signal.

  8. Heart rate variability reactivity and new romance: Cause or consequence?

    Science.gov (United States)

    Bailey, Laura K; Davis, Ron

    2017-09-01

    There are documented physiological differences between single and coupled individuals during the "honeymoon period" of nascent romantic relationships. One such difference is in autonomic reactivity, specifically heart rate variability (HRV) reactivity. This finding had previously been interpreted as evidence of a stress buffering effect of relationship formation. The present study explored among university women two competing longitudinal hypotheses conceptualizing differences in HRV reactivity as either a cause or a consequence of romantic relationship formation. Results did not support the hypothesis that HRV reactivity changes as a consequence of beginning a new romantic relationship. Instead, lower HRV reactivity predicted greater relationship formation amongst women with low BMI and higher resting HRV. The functioning of the heart therefore predicted the likelihood that an individual would find love. These interactions may be the result of differing success rates of various mating strategies for women with low and high BMI and HRV. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. An open source tool for heart rate variability spectral analysis.

    Science.gov (United States)

    Rodríguez-Liñares, L; Méndez, A J; Lado, M J; Olivieri, D N; Vila, X A; Gómez-Conde, I

    2011-07-01

    In this paper we describe a software package for developing heart rate variability analysis. This package, called RHRV, is a third party extension for the open source statistical environment R, and can be freely downloaded from the R-CRAN repository. We review the state of the art of software related to the analysis of heart rate variability (HRV). Based upon this review, we motivate the development of an open source software platform which can be used for developing new algorithms for studying HRV or for performing clinical experiments. In particular, we show how the RHRV package greatly simplifies and accelerates the work of the computer scientist or medical specialist in the HRV field. We illustrate the utility of our package with practical examples.

  10. Methods for heart rate variability analysis during sleep.

    Science.gov (United States)

    Bianchi, Anna M; Mendez, Martin O

    2013-01-01

    In the last years we have witnessed the growing interest in the heart rate variability (HRV) signal analysis during sleep. The study of the autonomic regulation during sleep allowed developing methods for automatic detection and classification of some sleep characteristics, both in physiological and pathological conditions. The main problems which require to be faced are the presence of frequent non-stationarities in the signal and the need of dealing with long term analysis, in order to provide reliable indices able to describe the whole night of sleep. In the present paper we are presenting some of the methodologies we recently employed in the study of the heart rate variability during sleep, ranging from time-frequency analysis to long time correlation. Some results are also presented, related to different applications, dealing with both physiological and pathological conditions.

  11. The effects of hypnosis on heart rate variability.

    Science.gov (United States)

    Yüksel, Ramazan; Ozcan, Osman; Dane, Senol

    2013-01-01

    Uslu et al. (2012 ) suggested that hypnotic status can modulate cerebral blood flow. The authors investigated the effects of hypnosis on heart rate variability (HRV). In women, HRV decreased during hypnosis. Posthypnotic values were higher compared to prehypnotic and hypnotic values. Women had highest HRV parameters in the posthypnotic condition. It appears that hypnosis can produce cardiac and cognitive activations. Hypnotherapy may be useful in some cardiac clinical conditions characterized by an autonomic imbalance or some cardiac arrhythmias.

  12. A DESIGN OF PORTABLE HEART-RATE MONITORING SYSTEM

    OpenAIRE

    ENGİN, Mehmet; DALBASTI, Tayfun; BILDIK, Saygın; KARIPÇIN, Turan; ENGIN, Erkan Zeki; CANER, Candan

    2012-01-01

    Telemedicine is producing a great impact in the monitoring of patients located in remote non-clinical environments such as homes, elder communities, gymnasiums, schools, remote military bases, ships, and rural area. A number of applications, ranging from data collection to chronic patient surveillance, and even to the control of therapeutic procedures, are being implemented in many parts of the world. As part of this growing trend, this paper explains the design of a portable heart-rate monit...

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

    OpenAIRE

    Lehrer, Paul M.; Richard eGevirtz

    2014-01-01

    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 ...

  14. Heritability of heart rate recovery and vagal rebound after exercise.

    Science.gov (United States)

    Nederend, Ineke; Schutte, Nienke M; Bartels, Meike; Ten Harkel, Arend D J; de Geus, Eco J C

    2016-12-01

    The prognostic power of heart rate recovery (HRR) after exercise has been well established but the exact origin of individual differences in HRR remains unclear. This study aims to estimate the heritability of HRR and vagal rebound after maximal exercise in adolescents. Furthermore, the role of voluntary regular exercise behavior (EB) in HRR and vagal rebound is tested. 491 healthy adolescent twins and their siblings were recruited for maximal exercise testing, followed by a standardized cooldown with measurement of the electrocardiogram and respiratory frequency. Immediate and long-term HRR (HRR60 and HRR180) and vagal rebound (heart rate variability in the respiratory frequency range) were assessed 1 and 3 min after exercise. Multivariate twin modeling was used to estimate heritability of all measured variables and to compute the genetic contribution to their covariance. Heritability of HRR60, HRR180 and immediate and long-term vagal rebound is 60 % (95 % CI: 48-67), 65 % (95 % CI: 54-73), 23 % (95 % CI: 11-35) and 3 % (95 % CI: 0-11), respectively. We find evidence for two separate genetic factors with one factor influencing overall cardiac vagal control, including resting heart rate and respiratory sinus arrhythmia, and a specific factor for cardiac vagal exercise recovery. EB was only modestly associated with resting heart rate (r = -0.27) and HRR (rHRR60 = 0.10; rHRR180 = 0.19) with very high genetic contribution to these associations (88-91 %). Individual differences in HRR and immediate vagal rebound can to a large extent be explained by genetic factors. These innate cardiac vagal exercise recovery factors partly reflect the effects of heritable differences in EB.

  15. Post-exercise heart rate recovery independently predicts mortality risk in patients with chronic heart failure.

    Science.gov (United States)

    Tang, Yi-Da; Dewland, Thomas A; Wencker, Detlef; Katz, Stuart D

    2009-12-01

    Post-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. We measured HRR (calculated as the difference between heart rate at peak exercise and after 1 minute of recovery) in 202 HF subjects and recorded 17 mortality and 15 urgent transplantation outcome events over 624 days of follow-up. Reduced post-exercise HRR was independently associated with increased event risk after adjusting for other exercise-derived variables (peak oxygen uptake and change in minute ventilation per change in carbon dioxide production slope), for the Heart Failure Survival Score (adjusted HR 1.09 for 1 beat/min reduction, 95% CI 1.05-1.13, P Heart Failure Model score (adjusted HR 1.08 for one beat/min reduction, 95% CI 1.05-1.12, P exercise HRR (>or=30 beats/min) had low risk of events irrespective of the risk predicted by the survival scores. In a subgroup of 15 subjects, reduced post-exercise HRR was associated with increased serum markers of inflammation (interleukin-6, r = 0.58, P = .024; high-sensitivity C-reactive protein, r = 0.66, P = .007). Post-exercise HRR predicts mortality risk in patients with HF and provides prognostic information independent of previously described survival models. Pathophysiologic links between autonomic function and inflammation may be mediators of this association.

  16. Is there a relationship between obesity, heart rate variability and inflammatory parameters in heart failure?

    Science.gov (United States)

    Taçoy, Gülten; Açikgöz, Kadri; Kocaman, Sinan Altan; Ozdemir, Murat; Cengel, Atiye

    2010-02-01

    To investigate the effect of body mass index (BMI) on heart rate variability (HRV) and inflammatory parameters in patients with heart failure. We analyzed 55 consecutive patients (mean age, 63.5 +/- 12.8 years; male/female, 39/16) with symptomatic left ventricular systolic (ejection fraction or= 30 kg/m2). The cause of heart failure was mainly ischemic heart disease (75%) with mean ejection fraction 30 +/- 7%. Plasma N-terminal pro-brain natriuretic peptide (NT-proBNP) and C-reactive protein levels were measured, and time-domain HRV indices were determined on Holter electrocardiogram. The relationship between HRV indices and laboratory, inflammatory and echocardiographic parameters was investigated with correlation analysis. Age, sex, clinical characteristics (hypertension, diabetes mellitus, dyslipidemia, family history, smoking) were similar between groups. BMI was inversely correlated with NT-pro BNP levels (P = 0.001). HRV indices did not differ between groups. Correlation analysis demonstrated the relationship between HRV indices and fasting blood glucose (SDNN, SDANN, SDNNI, root mean square successive differences, VTI), C-reactive protein (SDANN, SDNNI, VTI), pulmonary artery pressure (SDNN, SDANN, VTI) levels. In systolic heart failure patients a higher BMI is associated with decreased NT-proBNP levels. Although HRV indices were not different between groups, inflammatory parameters, fasting blood glucose and pulmonary artery pressure were correlated with them.

  17. Poincare indices for analyzing meditative heart rate signals

    Directory of Open Access Journals (Sweden)

    Atefeh Goshvarpour

    2015-06-01

    Full Text Available Background: Poincare plots are commonly used to study the nonlinear behavior of physiologic signals. The aim of this study is to evaluate the Poincare plot indices of human heart rate signals during meditation. Methods: For this purpose, heart rate time series of eight Chi meditators available in Physionet database were used. Poincare plots with lags of 1 and 6 were constructed, and the ratio of the minor axis to major axis (SD1/SD2 and the area of Poincare plots were calculated for each lag. Results: The results show that the SD1/SD2 ratio increased significantly during meditation compared to that before meditation, especially the index measured from Poincare plots reconstructed with a lag of 6 (p < 0.05. In addition, in both lags, the area of Poincare plots decreased significantly during meditation compared to before meditation (p < 0.05. Conclusion: The comparative dynamic measures of the Poincare plot indices during and before meditation give more insight of the heart rate signals in a specific psychophysiological state.

  18. Impaired post exercise heart rate recovery in anabolic steroid users.

    Science.gov (United States)

    dos Santos, M R; Dias, R G; Laterza, M C; Rondon, M U P B; Braga, A M F W; de Moraes Moreau, R L; Negrão, C E; Alves, M-J N N

    2013-10-01

    Previous study showed that muscle sympathetic nerve activity (MSNA) was augmented in anabolic steroids users (AASU). In the present study, we tested the hypothesis that the heart rate (HR) responses after maximal exercise testing would be reduced in AASU. 10 male AASU and 10 AAS nonusers (AASNU) were studied. Cardiopulmonary exercise was performed to assess the functional capacity and heart rate recovery. MSNA was recorded directly from the peroneal nerve by microneurography technique. Peak oxygen consumption (VO₂) was lower in AASU compared to AASNU (43.66±2.24 vs. 52.70±1.68 ml/kg/min, P=0.005). HR recovery (HRR) at first and second minute was lower in AASU than AASNU (21±2 vs. 27±2 bpm, P=0.02 and 37±4 vs. 45±2 bpm, P=0.05, respectively). MSNA was higher in AASU than AASNU (29±3 vs. 20±1 bursts/min, P=0.01). Further analysis showed a correlation between HRR and MSNA (r=- 0.64, P=0.02), HRR at first minute and peak VO₂ (r=0.70, P=0.01) and HRR at second minute and peak VO₂ (r=0.62, P=0.02). The exacerbated sympathetic outflow associated with a lower parasympathetic activation after maximal exercise, which impairs heart rate recovery, strengthens the idea of autonomic imbalance in AASU. © Georg Thieme Verlag KG Stuttgart · New York.

  19. Stress Detection Using Low Cost Heart Rate Sensors

    Directory of Open Access Journals (Sweden)

    Mario Salai

    2016-01-01

    Full Text Available The automated detection of stress is a central problem for ambient assisted living solutions. The paper presents the concepts and results of two studies targeted at stress detection with a low cost heart rate sensor, a chest belt. In the device validation study (n=5, we compared heart rate data and other features from the belt to those measured by a gold standard device to assess the reliability of the sensor. With simple synchronization and data cleaning algorithm, we were able to select highly (>97% correlated, low average error (2.2% data segments of considerable length from the chest data for further processing. The protocol for the clinical study (n=46 included a relax phase followed by a phase with provoked mental stress, 10 minutes each. We developed a simple method for the detection of the stress using only three time-domain features of the heart rate signal. The method produced accuracy of 74.6%, sensitivity of 75.0%, and specificity of 74.2%, which is impressive compared to the performance of two state-of-the-art methods run on the same data. Since the proposed method uses only time-domain features, it can be efficiently implemented on mobile devices.

  20. Characteristics of resonance in heart rate variability stimulated by biofeedback.

    Science.gov (United States)

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

    2006-06-01

    As we previously reported, resonant frequency heart rate variability biofeedback increases baroreflex gain and peak expiratory flow in healthy individuals and has positive effects in treatment of asthma patients. Biofeedback readily produces large oscillations in heart rate, blood pressure, vascular tone, and pulse amplitude via paced breathing at the specific natural resonant frequency of the cardiovascular system for each individual. This paper describes how resonance properties of the cardiovascular system mediate the effects of heart rate variability biofeedback. There is evidence that resonant oscillations can train autonomic reflexes to provide therapeutic effect. The paper is based on studies described in previous papers. Here, we discuss the origin of the resonance phenomenon, describe our procedure for determining an individual's resonant frequency, and report data from 32 adult asthma patients and 24 healthy adult subjects, showing a negative relationship between resonant frequency and height, and a lower resonant frequency in men than women, but no relationship between resonant frequency and age, weight, or presence of asthma. Resonant frequency remains constant across 10 sessions of biofeedback training. It appears to be related to blood volume.

  1. Practical remarks on the heart rate and saturation measurement methodology

    Science.gov (United States)

    Kowal, M.; Kubal, S.; Piotrowski, P.; Staniec, K.

    2017-05-01

    A surface reflection-based method for measuring heart rate and saturation has been introduced as one having a significant advantage over legacy methods in that it lends itself for use in special applications such as those where a person’s mobility is of prime importance (e.g. during a miner’s work) and excluding the use of traditional clips. Then, a complete ATmega1281-based microcontroller platform has been described for performing computational tasks of signal processing and wireless transmission. In the next section remarks have been provided regarding the basic signal processing rules beginning with raw voltage samples of converted optical signals, their acquisition, storage and smoothing. This chapter ends with practical remarks demonstrating an exponential dependence between the minimum measurable heart rate and the readout resolution at different sampling frequencies for different cases of averaging depth (in bits). The following section is devoted strictly to the heart rate and hemoglobin oxygenation (saturation) measurement with the use of the presented platform, referenced to measurements obtained with a stationary certified pulsoxymeter.

  2. Heart-rate recommendations: transfer between running and cycling exercise?

    Science.gov (United States)

    Roecker, K; Striegel, H; Dickhuth, H-H

    2003-04-01

    With the expanding use of portable heart rate (HR) monitors in endurance sports, HR is increasingly used as a marker for exercise intensity. Hereby, HR at the so-called individual anaerobic threshold (IAT) is one possible reference point. However, once determined, it is often attempted to apply HR recommendations from one type of ergometry to different kinds of exercises. We examined whether HR at IAT and at 4 mmol x l -1 blood lactate is predictable from cycling to running and vice versa. Data of 371 subjects (304 male, 67 female) were analyzed. All subjects underwent an incremental test on a treadmill (TR, starting speed 6 or 8 km x h -1, increments 2 km x h -1 every 3 min) and on a bicycle ergometer (BE, start at 50 Watt, increments 25 or 50 Watt every 3 min). IAT was determined at a net increase of lactate concentration of 1 - 5 mmol x l -1 above lactate concentration at lactate threshold for running (as in: Med Sci Sports Exerc 1998, 30 (10); 1552 - 1557) and 1.0 mmol x l -1 for cycling. A maximum time span of three weeks was allowed between the tests. We found that heart rate at IAT or at 4 mmol x l -1 blood lactate did not correlate between cycling and running. A sports specific test seems to be a prerequisite for reliable heart rate recommendations.

  3. Assessing heart rate variability through wavelet-based statistical measures.

    Science.gov (United States)

    Wachowiak, Mark P; Hay, Dean C; Johnson, Michel J

    2016-10-01

    Because of its utility in the investigation and diagnosis of clinical abnormalities, heart rate variability (HRV) has been quantified with both time and frequency analysis tools. Recently, time-frequency methods, especially wavelet transforms, have been applied to HRV. In the current study, a complementary computational approach is proposed wherein continuous wavelet transforms are applied directly to ECG signals to quantify time-varying frequency changes in the lower bands. Such variations are compared for resting and lower body negative pressure (LBNP) conditions using statistical and information-theoretic measures, and compared with standard HRV metrics. The latter confirm the expected lower variability in the LBNP condition due to sympathetic nerve activity (e.g. RMSSD: p=0.023; SDSD: p=0.023; LF/HF: p=0.018). Conversely, using the standard Morlet wavelet and a new transform based on windowed complex sinusoids, wavelet analysis of the ECG within the observed range of heart rate (0.5-1.25Hz) exhibits significantly higher variability, as measured by frequency band roughness (Morlet CWT: p=0.041), entropy (Morlet CWT: p=0.001), and approximate entropy (Morlet CWT: p=0.004). Consequently, this paper proposes that, when used with well-established HRV approaches, time-frequency analysis of ECG can provide additional insights into the complex phenomenon of heart rate variability.

  4. Experimental heart rate regulation in cycle-ergometer exercises.

    Science.gov (United States)

    Paradiso, Michele; Pietrosanti, Stefano; Scalzi, Stefano; Tomei, Patrizio; Verrelli, Cristiano Maria

    2013-01-01

    The heart rate can be effectively used as a measure of the exercise intensity during long duration cycle-ergometer exercises: precisely controlling the heart rate (HR) becomes crucial especially for athletes or patients with cardiovascular/obesity problems. The aim of this letter is to experimentally show how the nonlocal and nonswitching nonlinear control that has been recently proposed in the literature for the HR regulation in treadmill exercises can be effectively applied to cycle-ergometer exercises at constant cycling speed. The structure of the involved nonlinear model for the HR dynamics in cycle-ergometer exercises is mathematically inspired by the structure of a recently identified and experimentally validated nonlinear model for the HR dynamics in treadmill exercises: the role played by the treadmill speed is played here by the work load while the zero speed case for the treadmill exercise is here translated into the cycling operation under zero work load. Experimental results not only validate the aforementioned nonlinear model but also demonstrate the effectiveness--in terms of precise HR regulation--of an approach which simply generalizes to the nonlinear framework the classical proportional-integral control design. The possibility of online modifying the HR reference on the basis of the heart rate variability (HRV) is also suggested and experimentally motivated.

  5. Modeling heart rate variability including the effect of sleep stages

    Science.gov (United States)

    Soliński, Mateusz; Gierałtowski, Jan; Żebrowski, Jan

    2016-02-01

    We propose a model for heart rate variability (HRV) of a healthy individual during sleep with the assumption that the heart rate variability is predominantly a random process. Autonomic nervous system activity has different properties during different sleep stages, and this affects many physiological systems including the cardiovascular system. Different properties of HRV can be observed during each particular sleep stage. We believe that taking into account the sleep architecture is crucial for modeling the human nighttime HRV. The stochastic model of HRV introduced by Kantelhardt et al. was used as the initial starting point. We studied the statistical properties of sleep in healthy adults, analyzing 30 polysomnographic recordings, which provided realistic information about sleep architecture. Next, we generated synthetic hypnograms and included them in the modeling of nighttime RR interval series. The results of standard HRV linear analysis and of nonlinear analysis (Shannon entropy, Poincaré plots, and multiscale multifractal analysis) show that—in comparison with real data—the HRV signals obtained from our model have very similar properties, in particular including the multifractal characteristics at different time scales. The model described in this paper is discussed in the context of normal sleep. However, its construction is such that it should allow to model heart rate variability in sleep disorders. This possibility is briefly discussed.

  6. Effects of Stretching Exercise on Heart Rate Variability During Pregnancy.

    Science.gov (United States)

    Logan, Jeongok G; Yeo, SeonAe

    Little evidence exists for effects of low-intensity exercises such as stretching on cardiovascular health in pregnant women. Our aim was to evaluate the effect of a 20-minute stretching exercise on heart rate variability (HRV), blood pressure (BP), and heart rate (HR) in healthy pregnant women. In 15 pregnant women with a mean (SD) age of 29.47 (4.07) years and mean (SD) gestational weeks of 26.53 (8.35), HRV, and BP were measured before and after the 20-minute stretching exercise. Compared with before the stretching exercise, standard deviation of the normal-to-normal intervals, total variability of heart rate, increased by 7.40 milliseconds (t = -2.31, P = .04) and root mean square of successive differences, a surrogate measure of parasympathetic outflow, also increased by 11.68 milliseconds (Z = -2.04, P = .04) after the stretching exercise. Diastolic BP and HR decreased by 2.13 mm Hg (t = 1.93, P = .07) and 3.31 bpm (t = 2.17, P = .05), respectively, but they did not reach statistical significance. These preliminary data suggest that 20 minutes of stretching exercise may promote cardiovascular health by attenuating the loss of parasympathetic tone associated with pregnancy.

  7. SERCA1 Expression Enhances the Metabolic Efficiency of Improved Contractility in Post Ischemic Hearts

    Science.gov (United States)

    O'Donnell, J. Michael; Pound, Kayla; Xu, Xianyao; Lewandowski, E. Douglas

    2009-01-01

    Myocardial stunning is characterized by a metabolic uncoupling from function as mitochondrial tricarboxylic acid (TCA) cycle and oxygen consumption remain normal despite reduced contractility. Overexpression of the sarco-endoplasmic reticulum Ca2+-ATPase (SERCA1) in hearts has recently been reported to reduce dysfunction at reperfusion. In this study we determine whether the metabolic coupling to function improves with SERCA treatment. PBS (control) or adenovirus carrying the cDNA for SERCA1 were delivered via coronary perfusion in vivo to Sprague-Dawley rat hearts. Three days following gene transfer, isolated hearts were perfused with 0.4 mM [2,4,6,8,10,12,14,16-13C8] palmitate and 5 mM glucose, and subjected to 15 min ischemia followed by 40 min reperfusion. Consistent with myocardial stunning, rate-pressure-product (RPP) and left ventricular developed pressure (LVDP) were depressed 30-40% (p<0.05) in the PBS group. With SERCA1 overexpression, dP/dt was 20% greater than controls (p<0.05), and LVDP and RPP recovered to preischemic values. From dynamic 13C NMR, TCA cycle flux at reperfusion was similar to preischemic values for both groups. Therefore, the efficiency of coupling between cardiac work and TCA cycle flux was restored with SERCA1 treatment. Oxidative efficiency was also enhanced with SERCA1 as cytosolic NADH transport into the mitochondria was significantly greater compared to the PBS group. In addition, the phosphocreatine to ATP ratio (PCr/ATP) was not compromised with SERCA1 expression, despite enhanced function, and depressed fatty acid oxidation at 40 min reperfusion in the PBS group was not reversed with SERCA1. These data demonstrate metabolic coupling and NADH transport are significantly improved with SERCA1 treatment. PMID:19744494

  8. Introducing a novel mechanism to control heart rate in the ancestral Pacific hagfish.

    Science.gov (United States)

    Wilson, Christopher M; Roa, Jinae N; Cox, Georgina K; Tresguerres, Martin; Farrell, Anthony P

    2016-10-15

    Although neural modulation of heart rate is well established among chordate animals, the Pacific hagfish (Eptatretus stoutii) lacks any cardiac innervation, yet it can increase its heart rate from the steady, depressed heart rate seen in prolonged anoxia to almost double its normal normoxic heart rate, an almost fourfold overall change during the 1-h recovery from anoxia. The present study sought mechanistic explanations for these regulatory changes in heart rate. We provide evidence for a bicarbonate-activated, soluble adenylyl cyclase (sAC)-dependent mechanism to control heart rate, a mechanism never previously implicated in chordate cardiac control. © 2016. Published by The Company of Biologists Ltd.

  9. Resting autonomic modulations and the heart rate response to exercise.

    Science.gov (United States)

    Nunan, David; Jakovljevic, Djordje G; Donovan, Gay; Singleton, Lynette D; Sandercock, Gavin R H; Brodie, David A

    2010-08-01

    Identify the underlying role of resting heart rate variability (HRV) in the hearts response to graded exercise testing (GXT). Resting 5-min HRV and heart rate (HR) measurements were made in 33 volunteers (19 males, median age 34, range 25-63 years and 14 females median age 48, range 21-63 years). Measures of VO2 peak and HR obtained during a maximal GXT and heart rate recovery (HRR) post-GXT were assessed for associations with resting HRV. Differences and effect size (d) for measures of HRV were assessed between groups based on established risk cut-points for resting, exercise and recovery HR responses. Small associations were observed for the majority of resting HRV and GXT HR responses (best r value = -0.27, P > 0.05). Measures of HRV demonstrated moderate associations with HRR (best r value = 0.46, P < 0.05) and were able to predict a negative risk HRR. In contrast to other dependent variables, measures of HRV were consistently able to demonstrate significant and moderate to large (d = 0.9-2.0) differences between groups based on literature defined prognostic HR cut-points. Small associations with HR responses to exercise prevent their accurate prediction from resting HRV. Data support the use of vagally mediated resting HRV in predicting better HRR. Lower resting autonomic modulations underlined high risk resting and exercise HR responses. Resting short-term HRV measurements should be considered when assessing cardiac autonomic health from the HR response before, during and/or after exercise.

  10. Deep breathing heart rate variability is associated with inspiratory muscle weakness in chronic heart failure.

    Science.gov (United States)

    Reis, Michel Silva; Arena, Ross; Archiza, Bruno; de Toledo, Carlos Fischer; Catai, Aparecida Maria; Borghi-Silva, Audrey

    2014-03-01

    There is a synchronism between the respiratory and cardiac cycles. However, the relationship of inspiratory muscle weakness in chronic heart failure (CHF) on cardiac autonomic modulation is unknown. The purpose of the present investigation was to evaluate the impact of inspiratory muscle strength on the magnitude of respiratory sinus arrhythmia. Ten CHF (62 ± 7 years--left ventricle eject fraction of 40 ± 5% and New York Heart Association class I-III) and nine matched-age healthy volunteers (64 ± 5 years) participated in this study. Heart rate variability (HRV) was obtained at rest and during deep breathing manoeuvre (DB-M) by electrocardiograph. CHF patients demonstrated impaired cardiac autonomic modulation at rest and during DB-M when compared with healthy subjects (p heart rate was associated with inspiratory muscle weakness in CHF. Based on this evidence, recommendations for future research applications of respiratory muscle training can bring to light a potentially valuable target for rehabilitation. Copyright © 2013 John Wiley & Sons, Ltd.

  11. Bluetooth(Registered Trademark) Heart Rate Monitors for Spaceflight

    Science.gov (United States)

    Buxton, Roxanne E.; West, Michael R.; Kalogera, Kent L.; Hanson, Andrea M.

    2016-01-01

    Heart rate monitoring is required during exercise for crewmembers aboard the International Space Station (ISS) and will be for future exploration missions. The cardiovascular system must be sufficiently stressed throughout a mission to maintain the ability to perform nominal and contingency/emergency tasks. High quality heart rate data is required to accurately determine the intensity of exercise performed by the crewmembers and show maintenance of VO2max. The quality of the data collected on ISS is subject to multiple limitations and is insufficient to meet current requirements. PURPOSE: To evaluate the performance of commercially available Bluetooth® heart rate monitors (BT_HRM) and their ability to provide high quality heart rate data to monitor crew health on board ISS and during future exploration missions. METHODS: Nineteen subjects completed 30 data collection sessions of various intensities on the treadmill and/or cycle. Subjects wore several BT_HRM technologies for each testing session. One electrode-based chest strap (CS) was worn, while one or more optical sensors (OS) was worn. Subjects were instrumented with a 12-lead ECG to compare the heart rate data from the Bluetooth sensors. Each BT_RHM data set was time matched to the ECG data and a +/-5bpm threshold was applied to the difference between the two data sets. Percent error was calculated based on the number of data points outside the threshold and the total number of data points. REULTS: The electrode-based chest straps performed better than the optical sensors. The best performing CS was CS1 (1.6%error), followed by CS4 (3.3%error), CS3 (6.4%error), and CS2 (9.2%error). The OS resulted in 10.4% error for OS1 and 14.9% error for OS2. CONCLUSIONS: The highest quality data came from CS1, unfortunately it has been discontinued by the manufacturer. The optical sensors have not been ruled out for use, but more investigation is needed to determine how to get the best quality data. CS2 will be used in an

  12. Captopril Normalizes Insulin Signaling and Insulin-Regulated Substrate Metabolism in Obese (ob/ob) Mouse Hearts

    Science.gov (United States)

    Tabbi-Anneni, Imene; Buchanan, Jonathan; Cooksey, Robert C.; Abel, E. Dale

    2008-01-01

    The goal of this study was to determine whether inhibiting the renin-angiotensin system would restore insulin signaling and normalize substrate use in hearts from obese ob/ob mice. Mice were treated for 4 wk with Captopril (4 mg/kg·d). Circulating levels of free fatty acids, triglycerides, and insulin were measured and glucose tolerance tests performed. Rates of palmitate oxidation and glycolysis, oxygen consumption, and cardiac power were determined in isolated working hearts in the presence and absence of insulin, along with levels of phosphorylation of Akt and AMP-activated protein kinase (AMPK). Captopril treatment did not correct the hyperinsulinemia or impaired glucose tolerance in ob/ob mice. Rates of fatty acid oxidation were increased and glycolysis decreased in ob/ob hearts, and insulin did not modulate substrate use in hearts of ob/ob mice and did not increase Akt phosphorylation. Captopril restored the ability of insulin to regulate fatty acid oxidation and glycolysis in hearts of ob/ob mice, possibly by increasing Akt phosphorylation. Moreover, AMPK phosphorylation, which was increased in hearts of ob/ob mice, was normalized by Captopril treatment, suggesting that in addition to restoring insulin sensitivity, Captopril treatment improved myocardial energetics. Thus, angiotensin-converting enzyme inhibitors restore the responsiveness of ob/ob mouse hearts to insulin and normalizes AMPK activity independently of effects on systemic metabolic homeostasis. PMID:18450963

  13. Intracardiac Origin of Heart Rate Variability, Pacemaker Funny Current and their Possible Association with Critical Illness

    Science.gov (United States)

    Papaioannou, Vasilios E; Verkerk, Arie O; Amin, Ahmed S; de Bakker, Jaques MT

    2013-01-01

    Heart rate variability (HRV) is an indirect estimator of autonomic modulation of heart rate and is considered a risk marker in critical illness, particularly in heart failure and severe sepsis. A reduced HRV has been found in critically ill patients and has been associated with neuro-autonomic uncoupling or decreased baroreflex sensitivity. However, results from human and animal experimental studies indicate that intracardiac mechanisms might also be responsible for interbeat fluctuations. These studies have demonstrated that different membrane channel proteins and especially the so-called ‘funny’ current (If), an hyperpolarization-activated, inward current that drives diastolic depolarization resulting in spontaneous activity in cardiac pacemaker cells, are altered during critical illness. Furthermore, membrane channels kinetics seem to have significant impact upon HRV, whose early decrease might reflect a cellular metabolic stress. In this review article we present research findings regarding intracardiac origin of HRV, at the cellular level and in both isolated sinoatrial node and whole ex vivo heart preparations. In addition, we will review results from various experimental studies that support the interrelation between If and HRV during endotoxemia. We suggest that reduced HRV during sepsis could also be associated with altered pacemaker cell membrane properties, due to ionic current remodeling. PMID:22920474

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

    Directory of Open Access Journals (Sweden)

    Kasermann Hans P

    2007-08-01

    Full Text Available Abstract Background Pain of mild to moderate grade is difficult to detect in laboratory mice because mice are prey animals that attempt to elude predators or man by hiding signs of weakness, injury or pain. In this study, we investigated the use of telemetry to identify indicators of mild-to-moderate post-laparotomy pain. Results Adult mice were subjected to laparotomy, either combined with pain treatment (carprofen or flunixin, 5 mg/kg s/c bid, for 1 day or without pain relief. Controls received anesthesia and analgesics or vehicle only. Telemetrically measured locomotor activity was undisturbed in all animals, thus confirming that any pain experienced was of the intended mild level. No symptoms of pain were registered in any of the groups by scoring the animals' outer appearance or spontaneous and provoked behavior. In contrast, the group receiving no analgesic treatment after laparotomy demonstrated significant changes in telemetry electrocardiogram recordings: increased heart rate and decreased heart rate variability parameters pointed to sympathetic activation and pain lasting for 24 hours. In addition, core body temperature was elevated. Body weight and food intake were reduced for 3 and 2 days, respectively. Moreover, unstructured cage territory and destroyed nests appeared for 1–2 days in an increased number of animals in this group only. In controls these parameters were not affected. Conclusion In conclusion, real-time telemetric recordings of heart rate and heart rate variability were indicative of mild-to-moderate post-laparotomy pain and could define its duration in our mouse model. This level of pain cannot easily be detected by direct observation.

  15. Skinfold thickness is related to cardiovascular autonomic control as assessed by heart rate variability and heart rate recovery.

    Science.gov (United States)

    Esco, Michael R; Williford, Henry N; Olson, Michele S

    2011-08-01

    The purpose of this study was to determine if heart rate recovery (HRR) and heart rate variability (HRV) are related to maximal aerobic fitness and selected body composition measurements. Fifty men (age = 21.9 ± 3.0 years, height = 180.8 ± 7.2 cm, weight = 80.4 ± 9.1 kg, volunteered to participate in this study. For each subject, body mass index (BMI), waist circumference (WC), and the sum of skinfolds across the chest, abdomen, and thigh regions (SUMSF) were recorded. Heart rate variability (HRV) was assessed during a 5-minute period while the subjects rested in a supine position. The following frequency domain parameters of HRV were recorded: normalized high-frequency power (HFnu), and low-frequency to high-frequency power ratio (LF:HF). To determine maximal aerobic fitness (i.e., VO2max), each subject performed a maximal graded exercise test on a treadmill. Heart rate recovery was recorded 1 (HRR1) and 2 (HRR2) minutes during a cool-down period. Mean VO2max and BMI for all the subjects were 49.5 ± 7.5 ml·kg(-1)·min(-1) and 24.7 ± 2.2 kg·m(-2), respectively. Although VO2max, WC, and SUMSF was each significantly correlated to HRR and HRV, only SUMSF had a significant independent correlation to HRR1, HRR2, HFnu, LF:HF (p < 0.01). The results of the regression procedure showed that SUMSF accounted for the greatest variance in HRR1, HRR2, HFnu, and LF:HF (p < 0.01). The results of this study suggest that cardiovascular autonomic modulation is significantly related to maximal aerobic fitness and body composition. However, SUMSF appears to have the strongest independent relationship with HRR and HRV, compared to other body composition parameters and VO2max.

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

    Science.gov (United States)

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

    2014-03-01

    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. 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, ECGⅠ, ECGⅡ) 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. Among the intake groups, ECGⅡ 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 .05). Result of RPE during exercise according to intake groups, there was significant differences of each time (p .05). In conclusion, EDGⅡ 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.

  17. Predictive value of casual ECG-based resting heart rate compared with resting heart rate obtained from Holter recording.

    Science.gov (United States)

    Carlson, Nicholas; Dixen, Ulrik; Marott, Jacob L; Jensen, Magnus T; Jensen, Gorm B

    2014-03-01

    Elevated resting heart rate (RHR) is associated with cardiovascular mortality and morbidity. Assessment of heart rate (HR) from Holter recording may afford a more precise estimate of the effect of RHR on cardiovascular risk, as compared to casual RHR. Comparative analysis was carried out in an age-stratified subsample of 131 subjects in the Copenhagen City Heart Study (CCHS). Casual RHR was assessed from electrocardiograms recorded during clinical assessment. Hourly daytime HRs were mapped by Holter recording. Holter RHR was defined as the average of the lowest 3 hourly HRs recorded and mean HR calculated from all daytime HRs. Follow-up was recorded from public registers. Outcome measure was hazard rate for the combined endpoint of cardiovascular mortality, non-fatal heart failure and non-fatal acute myocardial infarction. Comparison of casual RHR, Holter RHR and mean HR by Multivariate Cox regression was performed. A total of 57 composite endpoints occurred during 17.1 years of follow-up. Regression analysis suggests correlation between Casual RHR and Holter RHR. Multivariate Cox regression analysis adjusted for gender and age demonstrated hazard rates of 1.02 (p = 0.079) for casual RHR, 1.04 (p = 0.036*) for Holter RHR, and 1.03 (p = 0.093) for mean HR for each 10 beat increment in HR. In a comparative analysis on the correlation and significance of differing RHR measurement modalities RHR measured by 24-hour Holter recording was found to be marginally superior as a predictor of cardiovascular morbidity and mortality. The results presented here do not however warrant the abandonment of a tested epidemiological variable.

  18. Auxin metabolism rates and implications for plant development

    Directory of Open Access Journals (Sweden)

    Eric M Kramer

    2015-03-01

    Full Text Available Studies of auxin metabolism rarely express their results as a metabolic rate, although the data obtained would often permit such a calculation to be made. We analyze data from 31 previously published papers to quantify the rates of auxin biosynthesis, conjugation, conjugate hydrolysis, and catabolism in seed plants. Most metabolic pathways have rates in the range 10 nM/h to 1 μM/h, with the exception of auxin conjugation, which has rates as high as ~100 μM/h. The highest rates of auxin conjugation suggests that auxin metabolic sinks may be very small, perhaps as small as a single cell. By contrast, the relatively low rate of auxin biosynthesis requires plants to conserve and recycle auxin during long-distance transport. The consequences for plant development are discussed.

  19. Fat in the heart: The enzymatic machinery regulating cardiac triacylglycerol metabolism.

    Science.gov (United States)

    Heier, Christoph; Haemmerle, Guenter

    2016-10-01

    The heart predominantly utilizes fatty acids (FAs) as energy substrate. FAs that enter cardiomyocytes can be activated and directly oxidized within mitochondria (and peroxisomes) or they can be esterified and intracellularly deposited as triacylglycerol (TAG) often simply referred to as fat. An increase in cardiac TAG can be a signature of the diseased heart and may implicate a minor role of TAG synthesis and breakdown in normal cardiac energy metabolism. Often overlooked, the heart has an extremely high TAG turnover and the transient deposition of FAs within the cardiac TAG pool critically determines the availability of FAs as energy substrate and signaling molecules. We herein review the recent literature regarding the enzymes and co-regulators involved in cardiomyocyte TAG synthesis and catabolism and discuss the interconnection of these metabolic pathways in the normal and diseased heart. This article is part of a Special Issue entitled: Heart Lipid Metabolism edited by G.D. Lopaschuk.

  20. Effects of atropine and pirenzepine on heart rate turbulence.

    Science.gov (United States)

    Vukajlovic, Dejan D; Guettler, Norbert; Miric, Milutin; Pitschner, Heinz Friedrich

    2006-01-01

    It has been shown that mortality risk in patients after myocardial infarction could be estimated by heart rate turbulence (HRT), a short-term change in heart rate after ventricular premature beat (VPB), presumably caused by baroreceptor mechanism. We sought to determine whether pharmacological blockade with atropine, or augmentation of vagal tone with pirenzepine given in small doses would influence HRT. In 30 patients with normal echocardiogram, and without signs or symptoms of coronary artery disease, after electrophysiologic examination or radiofrequency ablation for supraventricular arrhythmias was completed, turbulence onset (TO) and turbulence slope (TS) in basal state, after 1.3 mg IV pirenzepine and finally, after atropine in dose of 0.04 mg/kg of body weight were compared. As assessed by Friedman ANOVA test both pirenzepine and atropine caused a significant change in both TO (P pirenzepine to -5.99 +/- 5.6% (P pirenzepine to 26.8 +/- 19.9 ms/R-R interval (P pirenzepine from 706.8 +/- 106.8 to 830 +/- 151.9 ms (P pirenzepine increases HRT; vagal blockade with atropine decreases HRT. This finding suggests that a normal vagal innervation of heart is a prerequisite for the phenomenon of HRT.

  1. Heart rate turbulence and variability in patients with ventricular arrhythmias

    Directory of Open Access Journals (Sweden)

    Diego Tarricone

    2009-08-01

    Full Text Available Background: To evaluate the changes in autonomic neural control mechanisms before malignant ventricular arrhythmias, we measured heart rate variability (HRV and heart rate turbulence (HRT in patients with ventricular tachycardia or fibrillation (Group I; n=6, non sustained ventricular tachycardia (Group II; n=32, frequent premature ventricular beats (Group III; n=26 and with ICD implantation (Group IV; n=11. Methods: Time domain parameters of HRV and turbulence onset (TO and slope (TS were calculated on 24 hour Holter recordings. Normal values were: SDNN > 70 msec for HRV, TO <0% and TS >2.5 msec/RR-I for HRT. Results: Whereas SDNN was within normal range and similar in all study groups, HRT parameters were significantly different in patients who experienced VT/VF during Holter recording. Abnormal TO and/or TS were present in 100% of Group I patients and only in about 50% of Group II and IV. On the contrary, normal HRT parameters were present in 40-70% of Group II, III and IV patients and none of Group I. Conclusions: These data suggest that HRT analysis is more suitable than HRV to detect those transient alterations in autonomic control mechanisms that are likely to play a major trigger role in the genesis of malignant cardiac arrhythmias. (Heart International 2007; 3: 51-7

  2. Heart rate variability in patients with chronic cerebral ischemia

    Directory of Open Access Journals (Sweden)

    Smyshlaeva О.М.

    2010-12-01

    Full Text Available The purpose of the work is to estimate the status of autonomic nervous system in patients with chronic cerebral ischemia by means of the analysis of heart rate variability at various stages of disease. 120 patients with chronic cerebral ischemia aged from 45 to 65 took part in the research. The comparison group included 30 patients with an arterial hypertension and without chronic cerebral ischemia. Heart rate variability analisis included time-domain and frequency-domain methods of five-minute sequence of the electrocardiographic intervals registered in at rest and in or-thostatic probe. The results of research have shown, that autonomic disorders with prevalence of sympathetic nervous system accompany initial implications of chronic cerebral ischemia. The second stage of disease is characterized by depression of activity of both autonomic, and central regulation. The expressed depression of autonomic maintenance of regulation of heart rhythm of both from sympathetic, and from parasympathetic nervous system was observed at the third stage of chronic cerebral ischemia

  3. Ivabradine in acute coronary syndromes: Protection beyond heart rate lowering.

    Science.gov (United States)

    Niccoli, Giampaolo; Borovac, Josip Anđelo; Vetrugno, Vincenzo; Camici, Paolo G; Crea, Filippo

    2017-02-22

    Ivabradine is a heart rate reducing agent that exhibits anti-ischemic effects through the inhibition of funny electrical current in the sinus node resulting in heart rate reduction, thus enabling longer diastolic perfusion time, and reduced myocardial oxygen consumption without detrimental changes in arterial blood pressure, coronary vasomotion, and ventricular contractility. The current guideline-based clinical use of Ivabradine is reserved for patients with stable angina pectoris who cannot tolerate or whose symptoms are inadequately controlled with beta blockers. In patients with chronic heart failure and reduced ejection fraction, Ivabradine has demonstrated beneficial effects in improving clinical outcomes when added to conventional therapy. However, the role of Ivabradine in acute coronary syndromes has not been established. Based on the results from some relevant preclinical studies and a limited amount of clinical data that were reported recently, the role of Ivabradine in acute ischemic events warrants further investigation. The aim of this review is to provide an overview of the available literature on the potential role of Ivabradine in the clinical context of acute coronary syndromes.

  4. 多囊卵巢综合征患者静息心率与糖脂代谢及血压等指标关系的研究%Relationship among resting heart rate, glycolipid metabolism and blood pressure in patients with polycystic ovary syndrome

    Institute of Scientific and Technical Information of China (English)

    裴友娟; 王蔼明; 闫玲; 李敏

    2013-01-01

    Objective: To investigate the relationship among resting heart rate, glycolipid metabolism and blood pressure in patients with polycystic ovary syndrome(PCOS). Methods: Seventy seven patients with PCOS and seventy three healthy women volunteers as control were enrolled in the study in Department of Reproductive, Navy General Hospital from August 2011 to June 2012. The two groups were divided to four subgroups according to obese or non-obese. The serum levels of lipids, fasting blood glucose, blood glucose after meal, fasting insulin and insulin after meal were measured. The body weight, blood pressure and resting heart rate were calculated. Independent-samples t-test and partial correlation analysis were used to evaluate the relationship between resting heart rate and cardiovascular risk factors in patients with PCOS. Results: (1)The resting heart rate [(82. 09±7. 86)/min vs. (79. 55±5. 66)/min], body mass index (BMI), blood pressure, blood glucose and insulin in PCOS group were significantly higher than those in control(P<0. 05). (2) The resting heart rate was significantly correlated with BMI, systolic pressure, fasting insulin, insulin after 1 hour meal, and triglyceride (r = 0. 177, 0.191, 0.199, 0.204, 0.216 respectively, all P<0, 05). (3)The resting heart rate, systolic pressure, lipids and blood glucose after 1 hour in non-obese subgroup of PCOS were significantly higher than those in obese group of control. (4) After exclusion of confounding factors, such as BMI, diastolic pressure, fasting blood glucose and fasting insulin, the increase of systolic pressure (β=0. 237) and triglyceride level(β=0. 222) was independent risk factors for resting heart rate(P<0. 05) by multivariate linear regression analysis. Conclusions: The study indicates that increase of resting heart rate in PCOS patient is associated with increase of systolic pressure and triglyceride level. The resting heart rate in PCOS group is higher than that in control group along with increase

  5. Characterizing heart rate variability by scale-dependent Lyapunov exponent

    Science.gov (United States)

    Hu, Jing; Gao, Jianbo; Tung, Wen-wen

    2009-06-01

    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.

  6. Metabolically Derived Human Ventilation Rates: A Revised Approach Based Upon Oxygen Consumption Rates (Final Report, 2009)

    Science.gov (United States)

    EPA announced the availability of the final report, Metabolically Derived Human Ventilation Rates: A Revised Approach Based Upon Oxygen Consumption Rates. This report provides a revised approach for calculating an individual's ventilation rate directly from their oxygen c...

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

    Directory of Open Access Journals (Sweden)

    Smith Michael L

    2006-06-01

    Full Text Available Abstract Background Heart rate variability (HRV is known to be impaired in patients with congestive heart failure (CHF. Time-domain analysis of ECG signals traditionally relies heavily on linear indices of an essentially non-linear phenomenon. Poincaré plots are commonly used to study non-linear behavior of physiologic signals. Lagged Poincaré plots incorporate autocovariance information and analysis of Poincaré plots for various lags can provide interesting insights into the autonomic control of the heart. Methods Using Poincaré plot analysis, we assessed whether the relation of the lag between heart beats and HRV is altered in CHF. We studied the influence of lag on estimates of Poincaré plot indices for various lengths of beat sequence in a public domain data set (PhysioNet of 29 subjects with CHF and 54 subjects with normal sinus rhythm. Results A curvilinear association was observed between lag and Poincaré plot indices (SD1, SD2, SDLD and SD1/SD2 ratio in normal subjects even for a small sequence of 50 beats (p value for quadratic term 3 × 10-5, 0.002, 3.5 × 10-5 and 0.0003, respectively. This curvilinearity was lost in patients with CHF even after exploring sequences up to 50,000 beats (p values for quadratic term > 0.5. Conclusion Since lagged Poincaré plots incorporate autocovariance information, these analyses provide insights into the autonomic control of heart rate that is influenced by the non-linearity of the signal. The differences in lag-response in CHF patients and normal subjects exist even in the face of the treatment received by the CHF patients.

  8. Autonomic control of heart rate in the adult, aquatic Notophthalmus viridescens viridescens.

    Science.gov (United States)

    Pitkin, R B; Bonnet, K M

    1990-01-01

    1. We investigated the role of the autonomic nervous system in the control of the heart rate using an isolated heart preparation. 2. Addition of the parasympathetic blocker, atropine, to the organ bath resulted in an increase in heart rate as expected. 3. Addition of the sympathetic blocker, ergotamine, to the organ bath showed no change in the heart rate. 4. Addition of the sympathetic blocker, propranolol, to the organ bath resulted in the expected decrease in heart rate. 5. Both the sympathetic and parasympathetic nervous systems appear to play a role in the control of the heart rate.

  9. Heart rate responses to autonomic challenges in obstructive sleep apnea.

    Directory of Open Access Journals (Sweden)

    Paul M Macey

    Full Text Available Obstructive sleep apnea (OSA is accompanied by structural alterations and dysfunction in central autonomic regulatory regions, which may impair dynamic and static cardiovascular regulation, and contribute to other syndrome pathologies. Characterizing cardiovascular responses to autonomic challenges may provide insights into central nervous system impairments, including contributions by sex, since structural alterations are enhanced in OSA females over males. The objective was to assess heart rate responses in OSA versus healthy control subjects to autonomic challenges, and, separately, characterize female and male patterns. We studied 94 subjects, including 37 newly-diagnosed, untreated OSA patients (6 female, age mean ± std: 52.1 ± 8.1 years; 31 male aged 54.3 ± 8.4 years, and 57 healthy control subjects (20 female, 50.5 ± 8.1 years; 37 male, 45.6 ± 9.2 years. We measured instantaneous heart rate with pulse oximetry during cold pressor, hand grip, and Valsalva maneuver challenges. All challenges elicited significant heart rate differences between OSA and control groups during and after challenges (repeated measures ANOVA, p<0.05. In post-hoc analyses, OSA females showed greater impairments than OSA males, which included: for cold pressor, lower initial increase (OSA vs. control: 9.5 vs. 7.3 bpm in females, 7.6 vs. 3.7 bpm in males, OSA delay to initial peak (2.5 s females/0.9 s males, slower mid-challenge rate-of-increase (OSA vs. control: -0.11 vs. 0.09 bpm/s in females, 0.03 vs. 0.06 bpm/s in males; for hand grip, lower initial peak (OSA vs. control: 2.6 vs. 4.6 bpm in females, 5.3 vs. 6.0 bpm in males; for Valsalva maneuver, lower Valsalva ratio (OSA vs. control: 1.14 vs. 1.30 in females, 1.29 vs. 1.34 in males, and OSA delay during phase II (0.68 s females/1.31 s males. Heart rate responses showed lower amplitude, delayed onset, and slower rate changes in OSA patients over healthy controls, and impairments may be more pronounced in

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

    OpenAIRE

    Sarkar, A.; Barat, P.

    2006-01-01

    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 ...

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

    CERN Document Server

    Sarkar, A

    2006-01-01

    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.

  12. Insulin receptor substrate signaling controls cardiac energy metabolism and heart failure.

    Science.gov (United States)

    Guo, Cathy A; Guo, Shaodong

    2017-06-01

    The heart is an insulin-dependent and energy-consuming organ in which insulin and nutritional signaling integrates to the regulation of cardiac metabolism, growth and survival. Heart failure is highly associated with insulin resistance, and heart failure patients suffer from the cardiac energy deficiency and structural and functional dysfunction. Chronic pathological conditions, such as obesity and type 2 diabetes mellitus, involve various mechanisms in promoting heart failure by remodeling metabolic pathways, modulating cardiac energetics and impairing cardiac contractility. Recent studies demonstrated that insulin receptor substrates 1 and 2 (IRS-1,-2) are major mediators of both insulin and insulin-like growth factor-1 (IGF-1) signaling responsible for myocardial energetics, structure, function and organismal survival. Importantly, the insulin receptor substrates (IRS) play an important role in the activation of the phosphatidylinositide-3-dependent kinase (PI-3K) that controls Akt and Foxo1 signaling cascade, regulating the mitochondrial function, cardiac energy metabolism and the renin-angiotensin system. Dysregulation of this branch in signaling cascades by insulin resistance in the heart through the endocrine system promotes heart failure, providing a novel mechanism for diabetic cardiomyopathy. Therefore, targeting this branch of IRS→PI-3K→Foxo1 signaling cascade and associated pathways may provide a fundamental strategy for the therapeutic and nutritional development in control of metabolic and cardiovascular diseases. In this review, we focus on insulin signaling and resistance in the heart and the role energetics play in cardiac metabolism, structure and function. © 2017 Society for Endocrinology.

  13. Preconditioning in globally ischemic isolated rat hearts: effect on function and metabolic indices of myocardial damage

    NARCIS (Netherlands)

    M. Arad; J.W. de Jong (Jan Willem); R. de Jonge (Robert); T. Huizer (Tom); B. Rabinowitz

    1996-01-01

    textabstractWe assessed the effects of ischemic preconditioning on heart recovery and metabolic indices of damage following global ischemia and reperfusion, in relationship to post-ischemic lactate release. Three groups of Langendorff rat hearts were studied: (1) A control group of

  14. Preconditioning in globally ischemic isolated rat hearts: effect on function and metabolic indices of myocardial damage

    NARCIS (Netherlands)

    M. Arad; J.W. de Jong (Jan Willem); R. de Jonge (Robert); T. Huizer (Tom); B. Rabinowitz

    1996-01-01

    textabstractWe assessed the effects of ischemic preconditioning on heart recovery and metabolic indices of damage following global ischemia and reperfusion, in relationship to post-ischemic lactate release. Three groups of Langendorff rat hearts were studied: (1) A control group of

  15. Heart rate variability analysis in healthy subjects, patients suffering from congestive heart failure and heart transplanted patients

    Directory of Open Access Journals (Sweden)

    Argentina Leite

    2013-12-01

    Full Text Available This study aimed to find parameters to characterize heart rate variability (HRV and discriminate healthy subjects and patients with heart diseases. The parameters used for discrimination characterize the different components of HRV memory (short and long and are extracted from HRV recordings using parametric as well as non parametric methods. Thus, the parameters are: spectral components at low frequencies (LH and high frequencies (HF which are associated with the short memory of HRV and the long memory parameter (d obtained from autoregressive fractionally integrated moving average (ARFIMA models. In the non parametric context, short memory (α1 and long memory (α2 parameters are obtained from detrended fluctuation analysis (DFA. The sample used in this study contains 24-hour Holter HRV recordings of 30 subjects: 10 healthy individuals, 10 patients suffering from congestive heart failure and 10 heart transplanted patients from the Noltisalis database. It was found that short memory parameters present higher values for the healthy individuals whereas long memory parameters present higher values for the diseased individuals. Moreover, there is evidence that ARFIMA modeling allows the discrimination between the 3 groups under study, being advantageous over DFA.

  16. Heart rate turbulence predicts all-cause mortality and sudden death in congestive heart failure patients.

    Science.gov (United States)

    Cygankiewicz, Iwona; Zareba, Wojciech; Vazquez, Rafael; Vallverdu, Montserrat; Gonzalez-Juanatey, Jose R; Valdes, Mariano; Almendral, Jesus; Cinca, Juan; Caminal, Pere; de Luna, Antoni Bayes

    2008-08-01

    Abnormal heart rate turbulence (HRT) has been documented as a strong predictor of total mortality and sudden death in postinfarction patients, but data in patients with congestive heart failure (CHF) are limited. The aim of this study was to evaluate the prognostic significance of HRT for predicting mortality in CHF patients in New York Heart Association (NYHA) class II-III. In 651 CHF patients with sinus rhythm enrolled into the MUSIC (Muerte Subita en Insuficiencia Cardiaca) study, the standard HRT parameters turbulence onset (TO) and slope (TS), as well as HRT categories, were assessed for predicting total mortality and sudden death. HRT was analyzable in 607 patients, mean age 63 years (434 male), 50% of ischemic etiology. During a median follow up of 44 months, 129 patients died, 52 from sudden death. Abnormal TS and HRT category 2 (HRT2) were independently associated with increased all-cause mortality (HR: 2.10, CI: 1.41 to 3.12, P 120 ms. HRT is a potent risk predictor for both heart failure and arrhythmic death in patients with class II and III CHF.

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

    Science.gov (United States)

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

    1999-01-01

    OBJECTIVES: To determine whether the heart rate (HR) response to exercise in 21 highly trained cyclists (mean (SD) age 25 (3) years) was related to their heart dimensions. METHODS: Before performing an incremental exercise test involving a ramp protocol with workload increases of 25 W/min, each subject underwent echocardiographic evaluation of the following variables: left ventricular end diastolic internal diameter (LVIDd), left ventricular posterior wall thickness at end diastole (LVPWTd), interventricular septal wall thickness at end diastole (IVSTd), left ventricular mass index (LVMI), left atrial dimension (LAD), longitudinal left atrial (LLAD) and right atrial (LRAD) dimensions, and the ratio of early to late (E/A) diastolic flow velocity. RESULTS: The HR response showed a deflection point (HRd) at about 85% VO2MAX in 66.7% of subjects (D group; n = 14) and was linear in 33.3% (NoD group; n = 7). Several echocardiographic variables (LVMI, LAD, LLAD, LRAD) indicative of heart dimensions were similar in each group. However, mean LPWTd (p<0.01) and IVSTd (p<0.05) values were significantly higher in the D group. Finally, no significant difference between groups was found with respect to the E/A. CONCLUSIONS: The HR response is curvilinear during incremental exercise in a considerable number of highly trained endurance athletes-that is, top level cyclists. The departure of HR increase from linearity may predominantly occur in athletes with thicker heart walls. 


 PMID:10597846

  18. Variability of Lekanesphaera monodi metabolic rates with habitat trophic status

    Science.gov (United States)

    Vignes, Fabio; Fedele, Marialaura; Pinna, Maurizio; Mancinelli, Giorgio; Basset, Alberto

    2012-05-01

    Regulation of metabolism is a common strategy used by individuals to respond to a changing environment. The mechanisms underlying the variability of metabolic rates in macroinvertebrates are of primary importance in studying benthic-pelagic energy transfer in transitional water ecosystems. Lekanesphaera monodi is an isopod endemic to transitional water ecosystems that can modify its metabolic rate in response to environmental changes. Therefore it is a useful model in studying the influence of environmental factors on metabolism. This study focused on the interpopulation variability of standard metabolic rates (SMR) in L. monodi populations sampled in three transitional water ecosystems differing in their trophic status. The standard metabolic rates of L. monodi individuals across the same range of body size spectra were inferred from oxygen consumption measurements in a flow-through respirometer in the three populations and a body condition index was assessed for each population. Habitat trophic status was evaluated by monthly measurement of the basic physical-chemical parameters of the water column in the ecosystems for one year. Standard metabolic rates showed high variability, ranging from 0.27 to 10.14 J d-1. Body size accounted for more than 38% of total variability. In terms of trophic status, individuals from the eutrophic ecosystem had significantly higher standard metabolic rates than individuals from the other ecosystems (SMR = 2.3 J d-1 in Spunderati Sud vs. 1.36 J d-1 in Alimini and 0.69 J d-1 in Acquatina). The body conditions index was also higher in the population from the eutrophic ecosystem. Results show that standard metabolic rates and growth rates are directly related to habitat productivity in accordance with the expectations of the food habits hypothesis. A possible extension of this hypothesis to benthic invertebrates is proposed.

  19. Comparison of linear and nonlinear feedback control of heart rate for treadmill running

    National Research Council Canada - National Science Library

    Hunt, Kenneth J; Maurer, Roman R

    2016-01-01

    Heart rate can be used to define exercise intensity; feedback control systems for treadmills which automatically adjust speed to track arbitrary heart rate target profiles are therefore of interest...

  20. The normal range and determinants of the intrinsic heart rate in man.

    Science.gov (United States)

    Opthof, T

    2000-01-01

    Jose and Collison published a study on the normal range and the determinants of intrinsic heart rate in man in Cardiovascular Research in 1970 [Jose AD, Collison D. The normal range and determinants of the intrinsic heart rate in man. Cardiovasc Res 1970; 4: 160-167)]. The intrinsic heart rate is the heart rate under complete pharmacological blockade. They showed that (i) the resting heart rate is lower than the intrinsic heart rate and that (ii) the intrinsic heart rate declines with age. They also established that the variability in intrinsic heart rate between individuals of the same age is of the same order as the effect of ageing at the population level. This update discusses the relevance of these data with emphasis on sinus node function and autonomic balance. The paper of Jose and Collison was cited more than 200 times. The frequency of citation started to increase more than 10 years after publication.

  1. Comparison of rate assessment between resting heart rate and 24-hour Holter monitoring in patients with chronic atrial fibrillation.

    Science.gov (United States)

    Srisukwattana, Akanis; Krittayaphong, Rungroj

    2012-02-01

    Target heart rate in rate control strategy has been proposed by the Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) study. There is limited data on the correlation of measured heart rate at rest and during Holter monitoring. To evaluate the proportion of achieved target heart rate between resting heart rate measuring and 24-hour Holter monitoring in patients with chronic atrial fibrillation who receive rate control strategy. Patients with chronic atrial fibrillation who archived target resting heart rate under rate control strategy at Siriraj Hospital and who underwent 24-hour Holter monitoring were studied to evaluate the correlation between two methods of heart rate control. 47 patients were enrolled. Underlying cardiac conditions were as follows: hypertensive heart disease 44.7%, valvular heart disease 25%, coronary artery disease 17% and dilated cardiomyopathy 12.8%. There were 10 patients (21.3%) whose achieving target resting heart rate was not correlated with 24-hour Holter monitoring. Three patients (6.4%) underwent permanent pacemaker implantation due to sick sinus syndrome (SSS) or tachycardia-bradycardia syndrome. In chronic atrial fibrillation patients that receive rate control strategy, evaluation of only resting heart rate might not be enough for long-term evaluation and treatment and 24-hour monitoring may be an additional helpful test in order to more precisely adjust medication for long-term treatment and detection of SSS.

  2. Association between atrial fibrillatory rate and heart rate variability in patients with atrial fibrillation and congestive heart failure.

    Science.gov (United States)

    Corino, Valentina D A; Cygankiewicz, Iwona; Mainardi, Luca T; Stridh, Martin; Vasquez, Rafael; Bayes de Luna, Antonio; Holmqvist, Fredrik; Zareba, Wojciech; Platonov, Pyotr G

    2013-01-01

    Even if atrial fibrillatory rate (AFR) has been related to clinical outcome in patients with atrial fibrillation (AF), its relation with ventricular response has not been deeply studied. The aim of this study was to investigate the relation between AFR and RR series variability in patients with AF. Twenty-minute electrocardiograms in orthogonal leads were processed to extract AFR, using spatiotemporal QRST cancellation and time frequency analysis, and RR series in 127 patients (age 69 ± 11 years) with congestive heart failure (NYHA II-III) enrolled in the MUSIC study (MUerte Subita en Insufficiencia Cardiaca). Heart rate variability and irregularity were assessed by time domain parameters and entropy-based indices, respectively and their correlation with AFR investigated. Variability measures seem not to be related to AFR, while irregularity measures do. A significant correlation between AFR and variability parameters of heart rate variability during AF was found only in patients not treated with antiarrhythmics drugs (correlation = 0.56 P < 0.05 for pNN50), while this correlation was lost in patients taking rate- or rhythm-control drugs. A significant positive correlation between AFR and indices of RR irregularity was found, showing that a higher AFR is related to a less organized RR series (correlation = 0.33 P < 0.05 for regularity index for all patients, correlation increased in subgroups of patients treated with the same drug). These results suggest that a higher AFR is associated with a higher degree of irregularity of ventricular response that is observed regardless of the use of rate-controlling drugs. ©2012, Wiley Periodicals, Inc.

  3. Comparison of pulse rate variability with heart rate variability during obstructive sleep apnea.

    Science.gov (United States)

    Khandoker, Ahsan H; Karmakar, Chandan K; Palaniswami, Marimuthu

    2011-03-01

    We investigate whether pulse rate variability (PRV) extracted from finger photo-plethysmography (Pleth) waveforms can be the substitute of heart rate variability (HRV) from RR intervals of ECG signals during obstructive sleep apnea (OSA). Simultaneous measurements (ECG and Pleth) were taken from 29 healthy subjects during normal (undisturbed sleep) breathing and 22 patients with OSA during OSA events. Highly significant (pr>0.95) were found between heart rate (HR) and pulse rate (PR). Bland-Altman plot of HR and PR shows good agreement (sleep. However, several variability measures (SDNN, RMSSD, HF power, LF/HF and sample entropy) of PR and HR were found to be significantly (pheart rate variability under normal breathing in sleep but does not precisely reflect HRV in sleep disordered breathing.

  4. Optimum Heart Rate to Minimize Pulsatile External Cardiac Power

    Science.gov (United States)

    Pahlevan, Niema; Gharib, Morteza

    2011-11-01

    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.

  5. Omega-3 Polyunsaturated Fatty Acids and Heart Rate Variability

    Directory of Open Access Journals (Sweden)

    Jeppe Hagstrup Christensen

    2011-11-01

    Full Text Available Omega-3 polyunsaturated fatty acids (PUFA may modulate autonomic control of the heart because omega-3 PUFA is abundant in the brain and other nervous tissue as well as in cardiac tissue. This might partly explain why omega-3 PUFA offer some protection against sudden cardiac death (SCD. The autonomic nervous system is involved in the pathogenesis of SCD. Heart rate variability (HRV can be used as a non-invasive marker of cardiac autonomic control and a low HRV is a predictor for SCD and arrhythmic events. Studies on HRV and omega-3 PUFA have been performed in several populations such as patients with ischemic heart disease, patients with diabetes mellitus, patients with chronic renal failure, and in healthy subjects as well as in children.. The studies have demonstrated a positive association between cellular content of omega-3 PUFA and HRV and supplementation with omega-3 PUFA seems to increase HRV which could be a possible explanation for decreased risk of arrhythmic events and SCD sometimes observed after omega-3 PUFA supplementation. However, the results are not consistent and further research is needed

  6. Left ventricular assist device effects on metabolic substrates in the failing heart.

    Directory of Open Access Journals (Sweden)

    Lindsay B Weitzel

    Full Text Available BACKGROUND: Heart failure patients have inadequate nutritional intake and alterations in metabolism contributing to an overall energy depleted state. Left ventricular assist device (LVAD support is a common and successful intervention in patients with end-stage heart failure. LVAD support leads to alterations in cardiac output, functional status, neurohormonal activity and transcriptional profiles but the effects of LVADs on myocardial metabolism are unknown. This study set out to measure cardiac metabolites in non-failing hearts, failing hearts, and hearts post-LVAD support. METHODS: The study population consisted of 8 non-ischemic failing (at LVAD implant and 8 post-LVAD hearts, plus 8 non-failing hearts obtained from the tissue bank at the University of Colorado. NMR spectroscopy was utilized to evaluate differences in myocardial energy substrates. Paired and non-paired t-tests were used to determine differences between the appropriate groups. RESULTS: Glucose and lactate values both decreased from non-failing to failing hearts and increased again significantly in the (paired post-LVAD hearts. Glutamine, alanine, and aromatic amino acids decreased from non-failing to failing hearts and did not change significantly post-LVAD. Total creatine and succinate decreased from non-failing to failing hearts and did not change significantly post-LVAD. DISCUSSION: Measured metabolites related to glucose metabolism are diminished in failing hearts, but recovered their values post-LVAD. This differed from the amino acid levels, which decreased in heart failure but did not recover following LVAD. Creatine and the citric acid cycle intermediate succinate followed a similar pattern as the amino acid levels.

  7. Playing a violent television game affects heart rate variability.

    Science.gov (United States)

    Ivarsson, Malena; Anderson, Martin; Akerstedt, Torbjörn; Lindblad, Frank

    2009-01-01

    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. 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 variability (HRV) and physical activity were measured during gaming/participating and the night to follow using a portable combined heart rate and movement sensor. A sleep diary and questionnaires about gaming experiences and session-specific experiences were filled in. Criteria for Selection of Games: Violent game involves/rewards direct physical violence (no handguns) against another person, and nonviolent game involves/rewards no violence; same game design ('third-person game'); conducted in the same manner; no differences concerning motor activity; similar sound and light effects; no sexual content, violence against women or racial overtones. During violent (vs. nonviolent) gaming, there was significantly higher activity of the very low frequency component of the HRV and total power. During the night after playing, very low frequency, low frequency and high frequency components were significantly higher during the violent (vs. nonviolent) condition, just as total power. There were no significant differences between the three conditions (violent/nonviolent/no gaming) with respect to an index reflecting subjectively perceived sleep difficulties. Nor was there any difference between violent and nonviolent condition for any single sleep item. Violent gaming induces different autonomic responses in boys compared to nonviolent gaming--during playing and during the following night--suggesting different emotional responses. Subjectively perceived sleep quality is not influenced after a single gaming experience. Future studies should address the development of the autonomic balance after gaming over longer

  8. Prediction of Maximal Heart Rate in Children and Adolescents.

    Science.gov (United States)

    Gelbart, Miri; Ziv-Baran, Tomer; Williams, Craig A; Yarom, Yoni; Dubnov-Raz, Gal

    2017-03-01

    To identify a method to predict the maximal heart rate (MHR) in children and adolescents, as available prediction equations developed for adults have a low accuracy in children. We hypothesized that MHR may be influenced by resting heart rate, anthropometric factors, or fitness level. Cross-sectional study. Sports medicine center in primary care. Data from 627 treadmill maximal exercise tests performed by 433 pediatric athletes (age 13.7 ± 2.1 years, 70% males) were analyzed. Age, sex, sport type, stature, body mass, BMI, body fat, fitness level, resting, and MHR were recorded. To develop a prediction equation for MHR in youth, using stepwise multivariate linear regression and linear mixed model. To determine correlations between existing prediction equations and pediatric MHR. Observed MHR was 197 ± 8.6 b·min. Regression analysis revealed that resting heart rate, fitness, body mass, and fat percent were predictors of MHR (R = 0.25, P MHR variance, body mass added 5.7%, fat percent added 2.4%, and fitness added 1.2%. Existing adult equations had low correlations with observed MHR in children and adolescents (r = -0.03-0.34). A new equation to predict MHR in children and adolescents was developed, but was found to have low predictive ability, a finding similar to adult equations applied to children. Considering the narrow range of MHR in youth, we propose using 197 b·min as the mean MHR in children and adolescents, with 180 b·min the minimal threshold value (-2 standard deviations).

  9. Measurement Accuracy of Heart Rate and Respiratory Rate during Graded Exercise and Sustained Exercise in the Heat Using the Zephyr BioHarness™

    OpenAIRE

    Kim, J. -H.; Roberge, R.; Powell, J. B.; Shafer, A. B.; Williams, W. Jon

    2012-01-01

    The Zephyr BioHarness™ was tested to determine the accuracy of heart rate (HR) and respiratory rate (RR) measurements during 2 exercise protocols in conjunction with either a laboratory metabolic cart (Vmax) or a previously validated portable metabolic system (K4b2). In one protocol, HR and RR were measured using the BioHarness and Vmax during a graded exercise up to V̇O2max (n = 12). In another protocol, HR and RR were measured using the BH and K4b2 during sustained exercise (30 % and 50 % V...

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

    Science.gov (United States)

    Lehrer, Paul M.; Gevirtz, Richard

    2014-01-01

    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

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

    Directory of Open Access Journals (Sweden)

    Paul M Lehrer

    2014-07-01

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

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

    Science.gov (United States)

    Lehrer, Paul M; Gevirtz, Richard

    2014-01-01

    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.

  13. Simulation of heart rate variability model in a network

    Science.gov (United States)

    Cascaval, Radu C.; D'Apice, Ciro; D'Arienzo, Maria Pia

    2017-07-01

    We consider a 1-D model for the simulation of the blood flow in the cardiovascular system. As inflow condition we consider a model for the aortic valve. The opening and closing of the valve is dynamically determined by the pressure difference between the left ventricular and aortic pressures. At the outflow we impose a peripheral resistance model. To approximate the solution we use a numerical scheme based on the discontinuous Galerkin method. We also considering a variation in heart rate and terminal reflection coefficient due to monitoring of the pressure in the network.

  14. Mechanisms of high heart rate variability: a fresh look

    Directory of Open Access Journals (Sweden)

    Vladimir A. Lukyanchenko

    2016-05-01

    Full Text Available Consideration is being given herein to some mechanisms of high heart rate variability (high HRV, which cannot be attributed to sports exercise loading. The mechanism responsible for high HRV is explained as that resulted from the continuous performance (opening and closure of arteriovenous anastomoses in different organs and systems in a human organism. An assessment of this phenomenon is given herein from the point of view of a practicing physician who treats regularly patients with already established clinical diagnoses and those without an established nosological profile according to International Statistical Classification of Diseases and Related Health Problems 10th Revision.

  15. Transient suppression of heart rate complexity in concussed athletes.

    Science.gov (United States)

    La Fountaine, Michael F; Heffernan, Kevin S; Gossett, James D; Bauman, William A; De Meersman, Ronald E

    2009-06-15

    Heart rate variability (HRV) and complexity (HRC) were calculated at rest and during an isometric hand grip test (IHGT) within 48-hours (48 h) and two weeks (Week Two) of a concussion in athletes (CG) and control subjects. No differences were present at rest or in HRV during IGHT. HRC was significantly lower in the CG compared to controls at 48 h during IHGT. In CG at Week Two during IHGT, HRC was significantly greater than 48 h observations and not significantly different than controls. The findings suggest that HRC may have utility in detecting efferent cardiac autonomic anomalies within two weeks of concussion.

  16. Metabolic rates of giant pandas inform conservation strategies

    Science.gov (United States)

    Fei, Yuxiang; Hou, Rong; Spotila, James R.; Paladino, Frank V.; Qi, Dunwu; Zhang, Zhihe

    2016-06-01

    The giant panda is an icon of conservation and survived a large-scale bamboo die off in the 1980s in China. Captive breeding programs have produced a large population in zoos and efforts continue to reintroduce those animals into the wild. However, we lack sufficient knowledge of their physiological ecology to determine requirements for survival now and in the face of climate change. We measured resting and active metabolic rates of giant pandas in order to determine if current bamboo resources were sufficient for adding additional animals to populations in natural reserves. Resting metabolic rates were somewhat below average for a panda sized mammal and active metabolic rates were in the normal range. Pandas do not have exceptionally low metabolic rates. Nevertheless, there is enough bamboo in natural reserves to support both natural populations and large numbers of reintroduced pandas. Bamboo will not be the limiting factor in successful reintroduction.

  17. Metabolic Alkalosis:A Real Danger of Overdiuresis in Patients with Heart Failure

    Institute of Scientific and Technical Information of China (English)

    Yaseen Ali; Amila M. Parekh; Rahul K. Rao; Mirza R. Baig

    2015-01-01

    Chronic heart failure is one of the most common reasons for hospital admissions in the United States. A patient is diagnosed with heart failure when the heart is unable to do its physiological work of pumping the blood to the peripheral organs. At this time, the excess volume of lfuid can accumulate easily, leading to signs of lfuid overload. Loop diuretics has been at the forefront to alleviate these symptoms. It has its own side effects, but a lesser known and monitored is metabolic alkalosis. Herein, we reviewed a case where a patient developed metabolic alkalosis due to loop diuretics.

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

    Science.gov (United States)

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

    2008-01-01

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

  19. Bombesin-like receptor 3 regulates blood pressure and heart rate via a central sympathetic mechanism

    OpenAIRE

    Lateef, Dalya M.; Xiao, Cuiying; Brychta, Robert J.; Diedrich, Andr?; Schnermann, Jurgen; Reitman, Marc L.

    2016-01-01

    MK-5046, a bombesin-like receptor 3 (BRS-3) agonist, increases heart rate and blood pressure via increased central sympathetic tone. Brs3 null mice have a reduced resting heart rate that increases disproportionately with physical activity. BRS-3 contributes to the central regulation of heart rate and blood pressure.

  20. Discovery of novel heart rate-associated loci using the Exome Chip

    NARCIS (Netherlands)

    van den Berg, Marten E.; Warren, Helen R; Cabrera, Claudia P; Verweij, Niek; Mifsud, Borbala; Haessler, Jeffrey; Bihlmeyer, Nathan A.; Fu, Yi-Ping; Weiss, Stefan; Lin, Henry J.; Grarup, Niels; Li-Gao, Ruifang; Pistis, Giorgio; Shah, Nabi; Brody, Jennifer A.; Mueller-Nurasyid, Martina; Lin, Honghuang; Mei, Hao; Smith, Albert V.; Lyytikainen, Leo-Pekka; Hall, Leanne M; van Setten, Jessica; Trompet, Stella; Prins, Bram P.; Isaacs, Aaron; Radmanesh, Farid; Marten, Jonathan; Entwistle, Aiman; Kors, Jan A.; Silva, Claudia T; Alonso, Alvaro; Bis, Joshua C.; de Boer, Rudolf; de Haan, Hugoline G; de Mutsert, Renee; Dedoussis, George; Dominiczak, Anna F.; Doney, Alex S. F.; Ellinor, Patrick T.; Eppinga, Ruben N.; Felix, Stephan B.; Guo, Xiuqing; Hagemeijer, Yanick; Hansen, Torben; Harris, Tamara B.; Heckbert, Susan R.; Huang, Paul L.; Hwang, Shih-Jen; Kahonen, Mika; Kanters, Jorgen K.; Kolcic, Ivana; Launer, Lenore J.; Li, Man; Yao, Jie; Linneberg, Allan; Liu, Simin; MacFarlane, Peter W.; Mangino, Massimo; Morris, Andrew D.; Mulas, Antonella; Murray, Alison D.; Nelson, Christopher P.; Orru, Marco; Padmanabhan, Sandosh; Peters, Annette; Porteous, David J.; Poulter, Neil; Psaty, Bruce M.; Qi, Lihong; Raitakari, Olli T.; Rivadeneira, Fernando; Roselli, Carolina; Rudan, Igor; Sattar, Naveed; Sever, Peter; Sinner, Moritz F.; Soliman, Elsayed Z.; Spector, Timothy D.; Stanton, Alice V.; Stirrups, Kathleen E; Taylor, Kent D.; Tobin, Martin D.; Uitterlinden, Andre; Vaartjes, Ilonca; Hoes, Arno W.; van der Meer, Peter; Voelker, Uwe; Waldenberger, Melanie; Xie, Zhijun; Zoledziewska, Magdalena; Tinker, Andrew; Polasek, Ozren; Rosand, Jonathan; Jamshidi, Yalda; Duijn, Cornelia Mvan; Zeggini, Eleftheria; Jukema, Wouter J.; Asselbergs, Folkert W.; Samani, Nilesh J.; Lehtimaki, Terho; Gudnason, Vilmundur; Wilson, James G.; Lubitz, Steven A.; Kaeaeb, Stefan; Sotoodehnia, Nona; Caulfield, Mark J.; Palmer, Colin N. A.; Sanna, Serena; Mook-Kanamori, Dennis O.; Deloukas, Panos; Pedersen, Oluf; Rotter, Jerome I.; Doerr, Marcus; O'Donnell, Chris J.; Hayward, Caroline; Arking, Dan E.; Kooperberg, Charles; van der Harst, Pim; Eijgelsheim, Mark; Stricker, Bruno H.; Munroe, Patricia B.

    2017-01-01

    Resting heart rate is a heritable trait, and an increase in heart rate is associated with increased mortality risk. Genome-wide association study analyses have found loci associated with resting heart rate, at the time of our study these loci explained 0.9% of the variation. This study aims to

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

    Science.gov (United States)

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

    2010-01-01

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

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

    Science.gov (United States)

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

    2008-01-01

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

  3. Discovery of novel heart rate-associated loci using the Exome Chip

    NARCIS (Netherlands)

    van den Berg, Marten E.; Warren, Helen R; Cabrera, Claudia P; Verweij, Niek; Mifsud, Borbala; Haessler, Jeffrey; Bihlmeyer, Nathan A.; Fu, Yi-Ping; Weiss, Stefan; Lin, Henry J.; Grarup, Niels; Li-Gao, Ruifang; Pistis, Giorgio; Shah, Nabi; Brody, Jennifer A.; Mueller-Nurasyid, Martina; Lin, Honghuang; Mei, Hao; Smith, Albert V.; Lyytikainen, Leo-Pekka; Hall, Leanne M; van Setten, Jessica; Trompet, Stella; Prins, Bram P.; Isaacs, Aaron; Radmanesh, Farid; Marten, Jonathan; Entwistle, Aiman; Kors, Jan A.; Silva, Claudia T; Alonso, Alvaro; Bis, Joshua C.; de Boer, Rudolf; de Haan, Hugoline G; de Mutsert, Renee; Dedoussis, George; Dominiczak, Anna F.; Doney, Alex S. F.; Ellinor, Patrick T.; Eppinga, Ruben N.; Felix, Stephan B.; Guo, Xiuqing; Hagemeijer, Yanick; Hansen, Torben; Harris, Tamara B.; Heckbert, Susan R.; Huang, Paul L.; Hwang, Shih-Jen; Kahonen, Mika; Kanters, Jorgen K.; Kolcic, Ivana; Launer, Lenore J.; Li, Man; Yao, Jie; Linneberg, Allan; Liu, Simin; MacFarlane, Peter W.; Mangino, Massimo; Morris, Andrew D.; Mulas, Antonella; Murray, Alison D.; Nelson, Christopher P.; Orru, Marco; Padmanabhan, Sandosh; Peters, Annette; Porteous, David J.; Poulter, Neil; Psaty, Bruce M.; Qi, Lihong; Raitakari, Olli T.; Rivadeneira, Fernando; Roselli, Carolina; Rudan, Igor; Sattar, Naveed; Sever, Peter; Sinner, Moritz F.; Soliman, Elsayed Z.; Spector, Timothy D.; Stanton, Alice V.; Stirrups, Kathleen E; Taylor, Kent D.; Tobin, Martin D.; Uitterlinden, Andre; Vaartjes, Ilonca; Hoes, Arno W.; van der Meer, Peter; Voelker, Uwe; Waldenberger, Melanie; Xie, Zhijun; Zoledziewska, Magdalena; Tinker, Andrew; Polasek, Ozren; Rosand, Jonathan; Jamshidi, Yalda; Duijn, Cornelia Mvan; Zeggini, Eleftheria; Jukema, Wouter J.; Asselbergs, Folkert W.; Samani, Nilesh J.; Lehtimaki, Terho; Gudnason, Vilmundur; Wilson, James G.; Lubitz, Steven A.; Kaeaeb, Stefan; Sotoodehnia, Nona; Caulfield, Mark J.; Palmer, Colin N. A.; Sanna, Serena; Mook-Kanamori, Dennis O.; Deloukas, Panos; Pedersen, Oluf; Rotter, Jerome I.; Doerr, Marcus; O'Donnell, Chris J.; Hayward, Caroline; Arking, Dan E.; Kooperberg, Charles; van der Harst, Pim; Eijgelsheim, Mark; Stricker, Bruno H.; Munroe, Patricia B.

    2017-01-01

    Resting heart rate is a heritable trait, and an increase in heart rate is associated with increased mortality risk. Genome-wide association study analyses have found loci associated with resting heart rate, at the time of our study these loci explained 0.9% of the variation. This study aims to disco

  4. [Dynamics of heart rate changes in rats following stepwise change of treadmill running speed].

    Science.gov (United States)

    Tarasova, O S; Borzykh, A A; Kuz'min, I V; Borovik, A S; Lukoshkova, E V; Sharova, A P; Vinogradova, O L; Grigor'ev, A I

    2012-11-01

    Amplitude and temporal responses of heart rate to stepwise increase or decrease of treadmill running intensity were investigated in rats. Heart rate amplitude response was shown to be connected mainly with the change of sympathetic nervous activity whereas heart rate temporal response was shown to be determined predominantly by parasympathetic cardiotrophic influences.

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

    Science.gov (United States)

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

    2010-01-01

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

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

    Science.gov (United States)

    Stone, Michael H.; And Others

    1987-01-01

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

  7. A comparative study of pulse rate variability and heart rate variability in healthy subjects.

    Science.gov (United States)

    Wong, Jih-Sen; Lu, Wan-An; Wu, Kung-Tai; Liu, Margaret; Chen, Gau-Yang; Kuo, Cheng-Deng

    2012-04-01

    Both heart rate variability (HRV) and pulse rate variability (PRV) are noninvasive means for the assessment of autonomic nervous control of the heart. However, it is not settled whether or not the PRV obtained from either hand can be the surrogate of HRV. The HRV measures obtained from electrocardiographic signals and the PRV measures obtained from the pulse waves recorded from the index fingers of both hands were compared in normal subjects by using linear regression analysis and Bland and Altman method. Highly significant correlations (P < 0.001, 0.89 < r < 1.0) were found between all HRV measures and the corresponding PRV measures of both hands. However, there were insufficient agreements in some measures between pairwise comparisons among HRV, right PRV and left PRV except heart rate and ultra-low frequency power (ULFP). The PRV of either hand is close to, but not the same as the HRV in healthy subjects. The HRV, right PRV and left PRV are not surrogates of one another in normal subjects except heart rate and ULFP. Since HRV is generally accepted as the standard method for the assessment of the autonomic nervous modulation of a subject, the PRV of either hand may not be suitable for the assessment of the cardiac autonomic nervous modulation of the subject.

  8. Heart rate effects of intraosseous injections using slow and fast rates of anesthetic solution deposition.

    Science.gov (United States)

    Susi, Louis; Reader, Al; Nusstein, John; Beck, Mike; Weaver, Joel; Drum, Melissa

    2008-01-01

    The authors, using a crossover design, randomly administered, in a single-blind manner, 3 primary intraosseous injections to 61 subjects using: the Wand local anesthetic system at a deposition rate of 45 seconds (fast injection); the Wand local anesthetic system at a deposition rate of 4 minutes and 45 seconds (slow injection); a conventional syringe injection at a deposition rate of 4 minutes and 45 seconds (slow injection), in 3 separate appointments spaced at least 3 weeks apart. A pulse oximeter measured heart rate (pulse). The results demonstrated the mean maximum heart rate was statistically higher with the fast intraosseous injection (average 21 to 28 beats/min increase) than either of the 2 slow intraosseous injections (average 10 to 12 beats/min increase). There was no statistically significant difference between the 2 slow injections. We concluded that an intraosseous injection of 1.4 mL of 2% lidocaine with 1 : 100,000 epinephrine with the Wand at a 45-second rate of anesthetic deposition resulted in a significantly higher heart rate when compared with a 4-minute and 45-second anesthetic solution deposition using either the Wand or traditional syringe.

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

    Science.gov (United States)

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

    2013-01-01

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

  10. Expression of slow skeletal TnI in adult mouse hearts confers metabolic protection to ischemia

    Science.gov (United States)

    Pound, Kayla M.; Arteaga, Grace M.; Fasano, Mathew; Wilder, Tanganyika; Fischer, Susan K.; Warren, Chad M.; Wende, Adam R.; Farjah, Mariam; Abel, E. Dale; Solaro, R. John; Lewandowski, E. Douglas

    2011-01-01

    Changes in metabolic and myofilament phenotypes coincide in developing hearts. Posttranslational modification of sarcomere proteins influences contractility, affecting the energetic cost of contraction. However, metabolic adaptations to sarcomeric phenotypes are not well understood, particularly during pathophysiological stress. This study explored metabolic adaptations to expression of the fetal, slow skeletal muscle troponin I (ssTnI). Hearts expressing ssTnI exhibited no significant ATP loss during 5 minutes of global ischemia, while non-transgenic littermates (NTG) showed continual ATP loss. At 7 min ischemia TG-ssTnI hearts retained 80±12% of ATP vs. 49±6% in NTG (P<0.05). Hearts expressing ssTnI also had increased AMPK phosphorylation. The mechanism of ATP preservation was augmented glycolysis. Glycolytic end products (lactate and alanine) were 38% higher in TG-ssTnI than NTG at 2 min and 27% higher at 5 min. This additional glycolysis was supported exclusively by exogenous glucose, and not glycogen. Thus, expression of a fetal myofilament protein in adult mouse hearts induced elevated anaerobic ATP production during ischemia via metabolic adaptations consistent with the resistance to hypoxia of fetal hearts. The general findings hold important relevance to both our current understanding of the association between metabolic and contractile phenotypes and the potential for invoking cardioprotective mechanisms against ischemic stress. PMID:21640727

  11. Motion-compensated non-contact detection of heart rate

    Science.gov (United States)

    Yang, Lei; Liu, Ming; Dong, Liquan; Zhao, Yuejin; Liu, Xiaohua

    2015-12-01

    A new non-contact heart rate detection method based on the dual-wavelength technique is proposed and demonstrated experimentally. It is a well-known fact that the differences in the circuits of two detection modules result in different responses of two modules for motion artifacts. This poses a great challenge to compensate the motion artifacts during measurements. In order to circumvent this problem, we have proposed the amplitude spectrum and phase spectrum adaptive filter. Comparing with the time-domain adaptive filter and independent component analysis, the amplitude spectrum and phase spectrum adaptive filter can suppress the interference caused by the two circuit differences and effectively compensate the motion artifacts. To make the device is much compact and portable, a photoelectric probe is designed. The measurement distance is from several centimeters up to several meters. Moreover, the data obtained by using this non-contact detection system is compared with those of the conventional finger blood volume pulse (BVP) sensor by simultaneously measuring the heart rate of the subject. The data obtained from the proposed non-contact system are consistent and comparable with that of the BVP sensor.

  12. High frequency chest compression effects heart rate variability.

    Science.gov (United States)

    Lee, Jongwon; Lee, Yong W; Warwick, Warren J

    2007-01-01

    High frequency chest compression (HFCC) supplies a sequence of air pulses through a jacket worn by a patient to remove excessive mucus for the treatment or prevention of lung disease patients. The air pulses produced from the pulse generator propagates over the thorax delivering the vibration and compression energy. A number of studies have demonstrated that the HFCC system increases the ability to clear mucus and improves lung function. Few studies have examined the change in instantaneous heart rate (iHR) and heart rate variability (HRV) during the HFCC therapy. The purpose of this study is to measure the change of HRV with four experimental protocols: (a) without HFCC, (b) during Inflated, (c)HFCC at 6Hz, and (d) HFCC at 21Hz. The nonlinearity and regularity of HRV was assessed by approximate entropy (ApEn), a method used to quantify the complexities and randomness. To compute the ApEn, we sectioned with a total of eight epochs and displayed the ApEn over the each epoch. Our results show significant differences in the both the iHR and HRV between the experimental protocols. The iHR was elevated at both the (c) 6Hz and (d) 21Hz condition from without HFCC (10%, 16%, respectively). We also found that the HFCC system tends to increase the HRV. Our study suggests that monitoring iHR and HRV are very important physiological indexes during HFCC therapy.

  13. Human heart rate variability relation is unchanged during motion sickness

    Science.gov (United States)

    Mullen, T. J.; Berger, R. D.; Oman, C. M.; Cohen, R. J.

    1998-01-01

    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.

  14. Exercise heart rates in patients with hypertrophic cardiomyopathy.

    Science.gov (United States)

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

    2015-04-15

    The exercise heart rate (HR) profile and its relation to cardiac function and arrhythmias were investigated in patients with hypertrophic cardiomyopathy (HC). Chronotropic response (CR) and heart rate recovery (HRR) were computed during and after treadmill exercise testing in 273 patients with HC and 95 age-matched healthy controls. Patients with HC had higher prevalence of chronotropic incompetence and lower HRR1-5min compared with controls. Exercise capacity, diastolic function (assessed by E/e') and left atrial volume index were associated with HRR1min and CR in HC. Septal myectomy was associated with reduction in chronotropic incompetence but did not affect HRR1min. In conclusion, impaired CR and HRR1min are associated with advanced disease and do not appear to be independent clinical markers indicating high-risk status in HC. Improving CR by titrating doses of negative chronotropic agents, myectomy, and atrial pacing may be useful to increase exercise capacity in patients with HC. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. Noisy fluctuation of heart rate indicates cardiovascular system instability.

    Science.gov (United States)

    Fortrat, Jacques-Olivier; Baum, Charlotte; Jeanguillaume, Christian; Custaud, Marc-Antoine

    2013-09-01

    Heart rate spontaneously fluctuates despite homeostatic regulatory mechanisms to stabilize it. Harmonic and fractal fluctuations have been described. Non-harmonic non-fractal fluctuation has not been studied because it is usually thought that it is caused by apparatus noise. We hypothesized that this fluctuation looking like apparatus noise (that we call "noisy fluctuation") is linked to challenged blood pressure stabilization and not to apparatus noise. We assessed noisy fluctuation by quantifying the small and fastest beat-to-beat fluctuation of RR-interval by means of spectral analysis (Nyquist power of heart rate variability: nyHRV) after filtering out its fractal component. We observed nyHRV in healthy supine subjects and in patients with vasovagal symptoms. We challenged stabilization of blood pressure by upright posture (by means of a head-up tilt table test). Head-up position on the tilt table dramatically decreased nyHRV (0.128 ± 0.063 vs. 0.004 ± 0.002, p system is challenged (upright posture). It also indicates cardiovascular instability because it does not disappear in upright patients before vasovagal syncope, a transient failure of cardiovascular regulation.

  16. Effect of methamphetamine dependence on heart rate variability.

    Science.gov (United States)

    Henry, Brook L; Minassian, Arpi; Perry, William

    2012-05-01

    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. HRV was assessed using time domain, frequency domain, and non-linear entropic analyses in 17 previously METH-dependent and 21 drug-free comparison individuals during a 5 minute rest period. 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. 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.

  17. Heart rate variability in children with type 1 diabetes mellitus

    Directory of Open Access Journals (Sweden)

    Camila Balsamo Gardim

    2014-06-01

    Full Text Available 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.

  18. Power Spectral Analysis of Heart Rate Variability of Driver Fatigue

    Institute of Scientific and Technical Information of China (English)

    JIAO Kun; LI Zeng-yong; CHEN Ming; WANG Cheng-tao

    2005-01-01

    This investigation was to evaluate the driving fatigue based on power spectral analysis of heart rate variability (HRV) under vertical vibration. Forty healthy male subjects (29.7±3.5 years) were randomly divided into two groups, Group A (28.8±4.3 years) and Group B (30.6±2.7 years). Group A (experiment group) was required to perform the simulated driving and Group B (control group) kept calm for 90min. The frequency domain indices of HRV such as low frequency (0.040.15 Hz, LF), high frequency (0.15-0.4Hz, HF), LF/HF together with the indices of hemodynamics such as blood pressure (BP) and heart rate (HR) of the subjects between both groups were calculated and analyzed after the simulated driving. There were significances of the former indices between both groups (P<0.05). All the data collected after experiment of Group A was observed the remarkable linear correlation (P<0.05) and parameters and errors of their linear regression equation were stated (α=0.05, P<0.001) in this paper, respectively. The present study investigated that sympathetic activity of the subjects enhanced after the simulated driving while parasympathetic activities decreased. The sympathovagal balance was also improved. As autonomic function indictors of HRV reflected fatigue level, quantitative evaluation of driving mental fatigue from physiological reaction could be possible.

  19. Resting heart rate as predictor for left ventricular dysfunction and heart failure: MESA (Multi-Ethnic Study of Atherosclerosis).

    Science.gov (United States)

    Opdahl, Anders; Ambale Venkatesh, Bharath; Fernandes, Veronica R S; Wu, Colin O; Nasir, Khurram; Choi, Eui-Young; Almeida, Andre L C; Rosen, Boaz; Carvalho, Benilton; Edvardsen, Thor; Bluemke, David A; Lima, João A C

    2014-04-01

    The objective of this study was to investigate the relationship between baseline resting heart rate and incidence of heart failure (HF) and global and regional left ventricular (LV) dysfunction. The association of resting heart rate to HF and LV function has not been well described in an asymptomatic multi-ethnic population. Resting heart rate was measured in participants in the MESA (Multi-Ethnic Study of Atherosclerosis) trial at inclusion. Incident HF was registered (n = 176) during follow-up (median 7 years) in those who underwent cardiac magnetic resonance imaging (n = 5,000). Changes in ejection fraction (ΔEF) and peak circumferential strain (Δεcc) were measured as markers of developing global and regional LV dysfunction in 1,056 participants imaged at baseline and 5 years later. Time to HF (Cox model) and Δεcc and ΔEF (multiple linear regression models) were adjusted for demographics, traditional cardiovascular risk factors, calcium score, LV end-diastolic volume, and mass in addition to resting heart rate. Cox analysis demonstrated that for 1 beat/min increase in resting heart rate, there was a 4% greater adjusted relative risk for incident HF (hazard ratio: 1.04; 95% CI: 1.02 to 1.06; p heart rate was positively associated with deteriorating εcc and decrease in EF, even when all coronary heart disease events were excluded from the model. Elevated resting heart rate was associated with increased risk for incident HF in asymptomatic participants in the MESA trial. Higher heart rate was related to development of regional and global LV dysfunction independent of subclinical atherosclerosis and coronary heart disease. (Multi-Ethnic Study of Atherosclerosis [MESA]; NCT00005487). Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  20. Assessment of cardiac autonomic functions by heart rate recovery, heart rate variability and QT dynamicity parameters in patients with acromegaly.

    Science.gov (United States)

    Dural, Muhammet; Kabakcı, Giray; Cınar, Neşe; Erbaş, Tomris; Canpolat, Uğur; Gürses, Kadri Murat; Tokgözoğlu, Lale; Oto, Ali; Kaya, Ergün Barış; Yorgun, Hikmet; Sahiner, Levent; Dağdelen, Selçuk; Aytemir, Kudret

    2014-04-01

    Cardiovascular complications are the most common causes of morbidity and mortality in acromegaly. However, there is little data regarding cardiac autonomic functions in these patients. Herein, we aimed to investigate several parameters of cardiac autonomic functions in patients with acromegaly compared to healthy subjects. We enrolled 20 newly diagnosed acromegalic patients (55% female, age:45.7 ± 12.6 years) and 32 age- and gender-matched healthy subjects. All participants underwent 24 h Holter recording. Heart rate recovery (HRR) indices were calculated by subtracting 1st, 2nd and 3rd minute heart rates from maximal heart rate. All patients underwent heart rate variability (HRV) and QT dynamicity analysis. Baseline characteristics were similar except diabetes mellitus and hypertension among groups. Mean HRR1 (29.2 ± 12.3 vs 42.6 ± 6.5, p = 0.001), HRR2 (43.5 ± 15.6 vs 61.1 ± 10.8, p = 0.001) and HRR3 (46.4 ± 16.2 vs 65.8 ± 9.8, p = 0.001) values were significantly higher in control group. HRV parameters as, SDNN [standard deviation of all NN intervals] (p = 0.001), SDANN [SD of the 5 min mean RR intervals] (p = 0.001), RMSSD [root square of successive differences in RR interval] (p = 0.001), PNN50 [proportion of differences in successive NN intervals >50 ms] (p = 0.001) and high-frequency [HF] (p = 0.001) were significantly decreased in patients with acromegaly; but low frequency [LF] (p = 0.046) and LF/HF (p = 0.001) were significantly higher in acromegaly patients. QTec (p = 0.009), QTac/RR slope (p = 0.017) and QTec/RR slope (p = 0.01) were significantly higher in patients with acromegaly. Additionally, there were significant negative correlation of disease duration with HRR2, HRR3, SDNN, PNN50, RMSSD, variability index. Our study results suggest that cardiac autonomic functions are impaired in patients with acromegaly. Further large scale studies are needed to exhibit the prognostic significance of impaired autonomic functions in patients with

  1. Metabolic Profiles of Obesity in American Indians: The Strong Heart Family Study.

    Science.gov (United States)

    Zhao, Qi; Zhu, Yun; Best, Lyle G; Umans, Jason G; Uppal, Karan; Tran, ViLinh T; Jones, Dean P; Lee, Elisa T; Howard, Barbara V; Zhao, Jinying

    2016-01-01

    Obesity is a typical metabolic disorder resulting from the imbalance between energy intake and expenditure. American Indians suffer disproportionately high rates of obesity and diabetes. The goal of this study is to identify metabolic profiles of obesity in 431 normoglycemic American Indians participating in the Strong Heart Family Study. Using an untargeted liquid chromatography-mass spectrometry, we detected 1,364 distinct m/z features matched to known compounds in the current metabolomics databases. We conducted multivariate analysis to identify metabolic profiles for obesity, adjusting for standard obesity indicators. After adjusting for covariates and multiple testing, five metabolites were associated with body mass index and seven were associated with waist circumference. Of them, three were associated with both. Majority of the obesity-related metabolites belongs to lipids, e.g., fatty amides, sphingolipids, prenol lipids, and steroid derivatives. Other identified metabolites are amino acids or peptides. Of the nine identified metabolites, five metabolites (oleoylethanolamide, mannosyl-diinositol-phosphorylceramide, pristanic acid, glutamate, and kynurenine) have been previously implicated in obesity or its related pathways. Future studies are warranted to replicate these findings in larger populations or other ethnic groups.

  2. Contact-free heart rate measurement using multiple video data

    Science.gov (United States)

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

    2013-10-01

    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.

  3. Scientific Comparison of Different Online Heart Rate Monitoring Systems

    Directory of Open Access Journals (Sweden)

    Martin Schönfelder

    2011-01-01

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

  4. Estimating 'lost heart beats' rather than reductions in heart rate during the intubation of critically-ill children.

    Science.gov (United States)

    Jones, Peter; Ovenden, Nick; Dauger, Stéphane; Peters, Mark J

    2014-01-01

    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. 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. 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 [1]-[32] when atropine was not used compared to 0 [0-0] when atropine was used (pheart rate during intubation of 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.

  5. Physiological effects of bioceramic material: harvard step, resting metabolic rate and treadmill running assessments.

    Science.gov (United States)

    Leung, Ting-Kai; Kuo, Chia-Hua; Lee, Chi-Ming; Kan, Nai-Wen; Hou, Chien-Wen

    2013-12-31

    Previous biomolecular and animal studies have shown that a room-temperature far-infrared-rayemitting ceramic material (bioceramic) demonstrates physical-biological effects, including the normalization of psychologically induced stress-conditioned elevated heart rate in animals. In this clinical study, the Harvard step test, the resting metabolic rate (RMR) assessment and the treadmill running test were conducted to evaluate possible physiological effects of the bioceramic material in human patients. The analysis of heart rate variability (HRV) during the Harvard step test indicated that the bioceramic material significantly increased the high-frequency (HF) power spectrum. In addition, the results of RMR analysis suggest that the bioceramic material reduced oxygen consumption (VO2). Our results demonstrate that the bioceramic material has the tendency to stimulate parasympathetic responses, which may reduce resting energy expenditure and improve cardiorespiratory recovery following exercise.

  6. Physiological thermoregulation in a crustacean? Heart rate hysteresis in the freshwater crayfish Cherax destructor.

    Science.gov (United States)

    Goudkamp, Jacqueline E; Seebacher, Frank; Ahern, Mark; Franklin, Craig E

    2004-07-01

    Differential heart rates during heating and cooling (heart rate hysteresis) are an important thermoregulatory mechanism in ectothermic reptiles. We speculate that heart rate hysteresis has evolved alongside vascularisation, and to determine whether this phenomenon occurs in a lineage with vascularised circulatory systems that is phylogenetically distant from reptiles, we measured the response of heart rate to convective heat transfer in the Australian freshwater crayfish, Cherax destructor. Heart rate during convective heating (from 20 to 30 degrees C) was significantly faster than during cooling for any given body temperature. Heart rate declined rapidly immediately following the removal of the heat source, despite only negligible losses in body temperature. This heart rate 'hysteresis' is similar to the pattern reported in many reptiles and, by varying peripheral blood flow, it is presumed to confer thermoregulatory benefits particularly given the thermal sensitivity of many physiological rate functions in crustaceans.

  7. Gas exchange and heart rate in the harbour porpoise, Phocoena phocoena

    DEFF Research Database (Denmark)

    Reed, J.Z.; Chambers, C.; Hunter, C.J.

    2000-01-01

    The respiratory physiology, heart rates and metabolic rates of two captive juvenile male harbour porpoises (both 28 kg) were measured using a rapid-response respiratory gas analysis system in the laboratory. Breath-hold durations in the laboratory (12 +/- 0.3 s, mean +/- SEM) were shorter than...... a comparatively high minute rate of gas exchange. Oxygen consumption under these experimental conditions (247 +/- 13.8 ml O-2. min(-1)) was 1.9- fold higher than predicted by standard scaling relations. These data together with an estimate of the total oxygen stores predicted an aerobic dive limit of 5.4 min....... The peak end-tidal O-2 values were related to the length of the previous breath- hold, demonstrating the increased oxygen uptake from the lung for the longer dives. Blood oxygen capacity was 23.5 +/- 1.0 ml.100 ml(-1), and the oxygen affinity was high, enabling rapid oxygen loading during ventilation....

  8. Exercise stroke volume and heart rate response differ in right and left heart failure.

    Science.gov (United States)

    Groepenhoff, Herman; Westerhof, Nico; Jacobs, Wouter; Boonstra, Anco; Postmus, Piet E; Vonk-Noordegraaf, Anton

    2010-07-01

    In pulmonary arterial hypertension (PAH), the exercise-induced increase in stroke volume (SV) is limited by the increase in pulmonary artery pressure. In left heart failure (LHF), systemic arterial pressure increases little during exercise, and the SV increase is limited by the left ventricle itself. These differences might be reflected by a dissimilar SV and heart rate (HR) response to exercise, which could have important therapeutic implications, for example in beta-blocker therapy. Therefore, we tested the hypothesis that SV and HR responses during exercise are different between PAH and LHF patients. We included 28 PAH and 18 LHF patients (recruited from the heart failure unit) matched on a maximal oxygen uptake of exercise test. Only patients who had not been exposed to beta-blockers were included. Pulmonary arterial hypertension and LHF patient groups had equally impaired exercise tolerance (about 42% of predicted) with a maximal oxygen uptake of 0.80 +/- 0.29 and 0.86 +/- 0.19 L/min. The peak SV response to exercise was significantly lower in PAH patients (-14 mL, P = 0.01); this was compensated by a steeper slope of HR relating to oxygen uptake (0.03 beats/mL, P = 0.001). We conclude that PAH patients have a smaller SV response, but a larger HR response than LHF patients.

  9. A method to detect heart rate based on electrical bio-impedance

    Directory of Open Access Journals (Sweden)

    Li Kun-Yang

    2016-01-01

    Full Text Available As a basic health indicator, heart rate has been widely used in clinical measurement and daily health care. Electrical bio-impedance (EBI measurement provides non-invasive method for heart rate detection. Therefore, this paper proposed a method to detect heart rate based on EBI. With the BIOPAC EBI module, the signal can be de-noised in real-time. Finally, the de-noised EBI signal is used to compute heart rate. Four electrodes are located at radial artery of left upper limb in this method. The result proves that this method has high accuracy on heart rate measurement.

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

    Directory of Open Access Journals (Sweden)

    Charalampos D. Kriatselis

    2012-01-01

    Full Text Available Background. The purpose of this study was to assess the post-exercise O2 uptake and heart rate response in patients with heart failure (HF in comparison to healthy individuals. Methods and Results. Exercise testing of all subjects was conducted according to the RITE-protocol. The study subjects were classified according to their peak oxygen uptake (peak VO2 in four groups: healthy individuals with a peak VO2 >22 mL/kg/min (group 1, : 50, and patients with HF and a peak VO2 of 18–22 mL/kg/min, (group 2, : 48, 14–18 mL/kg/min (group 3, : 57, and <14 mL/kg/min (group 4, : 31. Both peak VO2 and HR declined more slowly in the patients with HF than in the normal subjects. Recovery of VO2 and HR followed monoexponential kinetics in the early post-recovery phase. This enabled the determination of a time constant for both HR and VO2 (TC VO2 and TC HR. From group 1 to 4 there was a prolongation of the time constant for VO2 and HR: TC VO2 (group 1: 110±34, group 2: 197±43, group 3: 238±80, and group 4: 278±50 sec, and TC HR (group 1: 148±82, group 2: 290±65, group 3: 320±58, and group 4: 376±55 sec. Conclusion. The rate of decline of VO2 and HR in the early post-exercise phase is inversely related to the peak VO2. The time constant for oxygen uptake (TC VO2 and heart rate (TC HR might prove a useful parameter for more precise monitoring and grading of HF.

  11. A role for BK channels in heart rate regulation in rodents.

    Directory of Open Access Journals (Sweden)

    Wendy L Imlach

    Full Text Available The heart generates and propagates action potentials through synchronized activation of ion channels allowing inward Na(+ and Ca(2+ and outward K(+ currents. There are a number of K(+ channel types expressed in the heart that play key roles in regulating the cardiac cycle. Large conductance calcium-activated potassium (BK ion channels are not thought to be directly involved in heart function. Here we present evidence that heart rate can be significantly reduced by inhibiting the activity of BK channels. Agents that specifically inhibit BK channel activity, including paxilline and lolitrem B, slowed heart rate in conscious wild-type mice by 30% and 42%, respectively. Heart rate of BK channel knock-out mice (Kcnma1(-/- was not affected by these BK channel inhibitors, suggesting that the changes to heart rate were specifically mediated through BK channels. The possibility that these effects were mediated through BK channels peripheral to the heart was ruled out with experiments using isolated, perfused rat hearts, which showed a significant reduction in heart rate when treated with the BK channel inhibitors paxilline (1 microM, lolitrem B (1 microM, and iberiotoxin (0.23 microM, of 34%, 60%, and 42%, respectively. Furthermore, paxilline was shown to decrease heart rate in a dose-dependent manner. These results implicate BK channels located in the heart to be directly involved in the regulation of heart rate.

  12. An Overview of Heart Rate Variability Metrics and Norms

    Directory of Open Access Journals (Sweden)

    Fred Shaffer

    2017-09-01

    Full Text Available Healthy biological systems exhibit complex patterns of variability that can be described by mathematical chaos. Heart rate variability (HRV consists of changes in the time intervals between consecutive heartbeats called interbeat intervals (IBIs. A healthy heart is not a metronome. The oscillations of a healthy heart are complex and constantly changing, which allow the cardiovascular system to rapidly adjust to sudden physical and psychological challenges to homeostasis. This article briefly reviews current perspectives on the mechanisms that generate 24 h, short-term (~5 min, and ultra-short-term (<5 min HRV, the importance of HRV, and its implications for health and performance. The authors provide an overview of widely-used HRV time-domain, frequency-domain, and non-linear metrics. Time-domain indices quantify the amount of HRV observed during monitoring periods that may range from ~2 min to 24 h. Frequency-domain values calculate the absolute or relative amount of signal energy within component bands. Non-linear measurements quantify the unpredictability and complexity of a series of IBIs. The authors survey published normative values for clinical, healthy, and optimal performance populations. They stress the importance of measurement context, including recording period length, subject age, and sex, on baseline HRV values. They caution that 24 h, short-term, and ultra-short-term normative values are not interchangeable. They encourage professionals to supplement published norms with findings from their own specialized populations. Finally, the authors provide an overview of HRV assessment strategies for clinical and optimal performance interventions.

  13. Separating the effect of respiration from the heart rate variability for cases of constant harmonic breathing

    Directory of Open Access Journals (Sweden)

    Kircher Michael

    2015-09-01

    Full Text Available Heart Rate Variability studies are a known measure for the autonomous control of the heart rate. In special situations, its interpretation can be ambiguous, since the respiration has a major influence on the heart rate variability. For this reason it has often been proposed to measure Heart Rate Variability, while the subjects are breathing at a constant respiration rate. That way the spectral influence of the respiration is known. In this work we propose to remove this constant respiratory influence from the heart rate and the Heart Rate Variability parameters to gain respiration free autonomous controlled heart rate signal. The spectral respiratory component in the heart rate signal is detected and characterized. Subsequently the respiratory effect on Heart Rate Variability is removed using spectral filtering approaches, such as the Notch filter or the Raised Cosine filter. As a result new decoupled Heart Variability parameters are gained, which could lead to new additional interpretations of the autonomous control of the heart rate.

  14. EFFECTS OF METABOLIC DRUG ELTACINE ON CLINICAL, FUNCTIONAL AND BIOCHEMICAL INDICES IN PATIENTS WITH CHRONIC HEART FAILURE

    Directory of Open Access Journals (Sweden)

    R. M. Zaslavskaya

    2015-12-01

    Full Text Available Aim. To study clinical efficacy of a new domestic metabolic drug Eltacine in patients with chronic heart failure (CHF.Material and methods. 134 patients with CHF of I-III functional classes were randomized in two parallel groups of patients receiving Eltacine or placebo additionally to standard therapy. Common clinical and laboratory investigations were used as well as 6-minute-walking test and Echocardiography. Besides Holter monitoring with determination of heart rate variability, peroxidal oxidation of lipids (POL and cell anti-oxidant protection were implemented.Results. Eltacine increased in tolerance to physical burden, improved cardiac haemodynamics, parameters of POL and cell anti-oxidant protection, improved the patient quality of life.Conclusion. The efficacy and safety of Eltacine as metabolic and antioxidant therapy was shown in patients with CHF.

  15. Heart rate and blood pressure: any possible implications for management of hypertension?

    Science.gov (United States)

    Reule, Scott; Drawz, Paul E

    2012-12-01

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

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

    Science.gov (United States)

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

    2013-08-01

    Although some information exists on the stress response of horses in equestrian sports, the horse-rider team is much less well understood. In this study, salivary cortisol concentrations, heart rate (HR) and heart rate variability (HRV), SDRR (standard deviation of beat-to-beat interval) and RMSSD (root mean square of successive beat-to-beat intervals) were analysed in horses and their riders (n=6 each) at a public performance and an identical rehearsal that was not open to the public. Cortisol concentrations increased in both horses and riders (Phorses and riders increased during the rehearsal and the public performance (Priders than in their horses during the public performance (from 91 ± 10 to 150 ± 15 beats/min) compared to the rehearsal (from 94 ± 10 to 118 ± 12 beats/min). The SDRR decreased significantly during the equestrian tasks in riders (Phorses. The RMSSD decreased in horses and riders (Priders was more pronounced (Priders than it did in their horses.

  17. Influence of polyunsaturated fatty acids on blood pressure, resting heart rate and heart rate variability among French Polynesians.

    Science.gov (United States)

    Valera, Beatriz; Suhas, Edouard; Counil, Emilie; Poirier, Paul; Dewailly, Eric

    2014-01-01

    To analyze the associations between marine n-3 polyunsaturated fatty acids (PUFAs) and blood pressure (BP), resting heart rate (HR), and heart rate variability (HRV) in a population highly exposed to methylmercury through the diet. Concentrations of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) in erythrocytes membranes were measured in 180 French Polynesian adults (≥18 years) residing in Tubuai, which is a community with a traditional lifestyle, or Papeete, which has a modern lifestyle. HRV was measured using a 2-hour ambulatory electrocardiogram (Holter). Resting HR and BP were measured using standardized protocols and pulse pressure (PP) was calculated as systolic BP - diastolic BP. The associations between n-3 PUFAs and the dependent variables were studied using simple and multiple linear regressions. Increasing DHA concentration was associated with lower resting HR (β = -2.57, p = 0.005) and diastolic BP (β = -1.96, p = 0.05) and higher HRV in multivariable models. Specifically, DHA was associated with high frequency (HF; β = 0.19, p = 0.02) and the square root of the mean squared differences of successive R-R intervals (difference between two consecutive R waves; rMSSD; β = 0.08, p = 0.03), which are specific indices of the parasympathetic activity of the autonomic nervous system. DHA was associated with lower BP and resting HR and higher HRV among French Polynesians who are also exposed to high methylmercury levels.

  18. Chemical sympathectomy restores baroreceptor-heart rate reflex and heart rate variability in rats with chronic nitric oxide deficiency.

    Science.gov (United States)

    Chaswal, M; Das, S; Prasad, J; Katyal, A; Fahim, M

    2015-01-01

    Nitric oxide (NO) plays a crucial role not only in regulation of blood pressure but also in maintenance of cardiac autonomic tone and its deficiency induced hypertension is accompanied by cardiac autonomic dysfunction. However, underlying mechanisms are not clearly defined. We hypothesized that sympathetic activation mediates hemodynamic and cardiac autonomic changes consequent to deficient NO synthesis. We used chemical sympathectomy by 6-hydroxydopamine to examine the influence of sympathetic innervation on baroreflex sensitivity (BRS) and heart rate variability (HRV) of chronic N(G)-nitro-L-arginine methyl ester (L-NAME) treated adult Wistar rats. BRS was determined from heart rate responses to changes in systolic arterial pressure achieved by intravenous administration of phenylephrine and sodium nitroprusside. Time and frequency domain measures of HRV were calculated from 5-min electrocardiogram recordings. Chronic L-NAME administration (50 mg/kg per day for 7 days orally through gavage) in control rats produced significant elevation of blood pressure, tachycardia, attenuation of BRS for bradycardia and tachycardia reflex and fall in time as well as frequency domain parameters of HRV. Sympathectomy completely abolished the pressor as well as tachycardic effect of chronic L-NAME. In addition, BRS and HRV improved after removal of sympathetic influence in chronic L-NAME treated rats. These results support the concept that an exaggerated sympathetic activity is the principal mechanism of chronic L-NAME hypertension and associated autonomic dysfunction.

  19. Resting Heart Rate as Predictor for Left Ventricular Dysfunction and Heart Failure: The Multi-Ethnic Study of Atherosclerosis

    Science.gov (United States)

    Opdahl, Anders; Venkatesh, Bharath Ambale; Fernandes, Veronica R. S.; Wu, Colin O.; Nasir, Khurram; Choi, Eui-Young; Almeida, Andre L. C.; Rosen, Boaz; Carvalho, Benilton; Edvardsen, Thor; Bluemke, David A.; Lima, Joao A. C.

    2014-01-01

    OBJECTIVE To investigate the relationship between baseline resting heart rate and incidence of heart failure (HF) and global and regional left ventricular (LV) dysfunction. BACKGROUND The association of resting heart rate to HF and LV function is not well described in an asymptomatic multi-ethnic population. METHODS Participants in the Multi-Ethnic Study of Atherosclerosis had resting heart rate measured at inclusion. Incident HF was registered (n=176) during follow-up (median 7 years) in those who underwent cardiac MRI (n=5000). Changes in ejection fraction (ΔEF) and peak circumferential strain (Δεcc) were measured as markers of developing global and regional LV dysfunction in 1056 participants imaged at baseline and 5 years later. Time to HF (Cox model) and Δεcc and ΔEF (multiple linear regression models) were adjusted for demographics, traditional cardiovascular risk factors, calcium score, LV end-diastolic volume and mass in addition to resting heart rate. RESULTS Cox analysis demonstrated that for 1 bpm increase in resting heart rate there was a 4% greater adjusted relative risk for incident HF (Hazard Ratio: 1.04 (1.02, 1.06 (95% CI); Pheart rate was positively associated with deteriorating εcc and decrease in EF, even in analyses when all coronary heart disease events were excluded from the model. CONCLUSION Elevated resting heart rate is associated with increased risk for incident HF in asymptomatic participants in MESA. Higher heart rate is related to development of regional and global LV dysfunction independent of subclinical atherosclerosis and coronary heart disease. PMID:24412444

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

    Science.gov (United States)

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

    2008-01-01

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

  1. Unobtrusive heart rate monitor based on a fiber specklegram sensor and a single-board computer

    Science.gov (United States)

    Benevides, Alessandro B.; Frizera, Anselmo; Cotrina, Anibal; Ribeiro, Moisés. R. N.; Segatto, Marcelo E. V.; Pontes, Maria José

    2015-09-01

    This paper proposes a portable and unobtrusive heart rate monitor based on fiber specklegram sensors. The proposed module uses the Raspberry Pi module to perform the image acquisition and the fiber specklegram sensor, which is based on multimode plastic optical fibers. The heart rate is obtained by welch power spectral density estimate and the heart beats are identified by means of a threshold analysis.

  2. Exercise Training Improves Heart Rate Variability after Methamphetamine Dependency

    Science.gov (United States)

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

    2014-01-01

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

  3. Predictive value of casual ECG-based resting heart rate compared with resting heart rate obtained from Holter recording

    DEFF Research Database (Denmark)

    Carlson, Nicholas; Dixen, Ulrik; Marott, Jacob L

    2014-01-01

    HRs recorded and mean HR calculated from all daytime HRs. Follow-up was recorded from public registers. Outcome measure was hazard rate for the combined endpoint of cardiovascular mortality, non-fatal heart failure and non-fatal acute myocardial infarction. Comparison of casual RHR, Holter RHR...... rates of 1.02 (p = 0.079) for casual RHR, 1.04 (p = 0.036*) for Holter RHR, and 1.03 (p = 0.093) for mean HR for each 10 beat increment in HR. CONCLUSIONS: In a comparative analysis on the correlation and significance of differing RHR measurement modalities RHR measured by 24-hour Holter recording...... was found to be marginally superior as a predictor of cardiovascular morbidity and mortality. The results presented here do not however warrant the abandonment of a tested epidemiological variable....

  4. Impact of the renin-angiotensin system on cardiac energy metabolism in heart failure.

    Science.gov (United States)

    Mori, Jun; Zhang, Liyan; Oudit, Gavin Y; Lopaschuk, Gary D

    2013-10-01

    The renin-angiotensin system (RAS) plays a key pathogenic role in heart failure. The adverse effects of angiotensin II (Ang II), a major player of the RAS, contributes to the development of heart failure. Heart failure is accompanied by significant perturbations in cardiac energy metabolism that can both decrease cardiac energy supply and decrease cardiac efficiency. Recent evidence suggests that Ang II might be involved in these perturbations in cardiac energy metabolism. Furthermore, new components of the RAS, such as angiotensin converting enzyme 2 and Ang1-7, have been reported to exert beneficial effects on cardiac energy metabolism. As a result, a further understanding of the relationship between the RAS and cardiac energy metabolism has the potential to improve the control of heart failure, and may lead to the development of new therapies to treat heart failure. This review summarizes what effects the RAS has on cardiac energy metabolism, highlighting how Ang II can induce cardiac insulin resistance and mitochondrial damage, and what role reactive oxygen species and sirtuins have on these processes.

  5. Exercise Heart Rate Reserve and Recovery as Predictors of Incident Type 2 Diabetes.

    Science.gov (United States)

    Jae, Sae Young; Kurl, Sudhir; Laukkanen, Jari A; Zaccardi, Francesco; Choi, Yoon-Ho; Fernhall, Bo; Carnethon, Mercedes; Franklin, Barry A

    2016-05-01

    We tested the hypothesis that selected exercise heart rate responses, specifically those providing indices of autonomic dysfunction, may be associated with incident type 2 diabetes in 2231 apparently healthy men with normal baseline fasting glucose levels. Heart rate reserve was calculated as the difference between the maximal attained heart rate and the supine resting heart rate, whereas heart rate recovery was defined as the maximal heart rate minus the heart rate measured at 2 minutes of recovery after peak or symptom-limited cardiopulmonary exercise testing. Type 2 diabetes was defined as glycated hemoglobin >6.5% or fasting plasma glucose >126 mg/dL at the follow-up examination. During a median follow-up interval of 5 years, 90 of the 2231 men (4.0%) developed type 2 diabetes. The relative risks of incident type 2 diabetes in men within the lowest quartiles of heart rate reserve and heart rate recovery versus men comprising the highest quartiles of heart rate reserve and heart rate recovery were 2.71 (95% confidence interval, 1.20-6.11) and 2.81 (95% confidence interval, 1.36-5.78) after adjusting for potential confounding variables. Each unit increment (1 beat/min) in heart rate reserve and heart rate recovery was associated with a 2% to 3% decreased incidence of type 2 diabetes. Exercise heart rate reserve and recovery predicted incidence of type 2 diabetes in healthy men, suggesting that autonomic dysfunction may be associated with an increased likelihood for the development of this cardiometabolic risk factor. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Hypoxia-driven glycolytic and fructolytic metabolic programs: Pivotal to hypertrophic heart disease.

    Science.gov (United States)

    Mirtschink, Peter; Krek, Wilhelm

    2016-07-01

    Pathologic cardiac growth is an adaptive response of the myocardium to various forms of systemic (e.g. pressure overload) or genetically-based (e. g. mutations in genes encoding sarcomeric proteins) stress. It represents a key aspect of different types of heart disease including aortic stenosis (AS) and hypertrophic cardiomyopathy (HCM). While many of the pathophysiological and hemodynamical aspects of pathologic cardiac hypertrophy have been uncovered during the last decades, its underlying metabolic determinants are only beginning to come into focus. Here, we review the epidemiological evidence and pathological features of hypertrophic heart disease in AS and HCM and consider in this context the development of microenvironmental tissue hypoxia as a key component of the heart's growth response to pathologic stress. We particularly reflect on recent evidence illustrating how activation of hypoxia-inducible factor (HIF) drives glycolytic and fructolytic metabolic programs to maintain ATP generation and support anabolic growth of the pathologically-stressed heart. Finally we discuss how this metabolic programs, when protracted, deprive the heart of energy leading ultimately to heart failure. This article is part of a Special Issue entitled: Cardiomyocyte Biology: Integration of Developmental and Environmental Cues in the Heart edited by Marcus Schaub and Hughes Abriel.

  7. Comprehensive metabolic modeling of multiple 13C-isotopomer data sets to study metabolism in perfused working hearts.

    Science.gov (United States)

    Crown, Scott B; Kelleher, Joanne K; Rouf, Rosanne; Muoio, Deborah M; Antoniewicz, Maciek R

    2016-10-01

    In many forms of cardiomyopathy, alterations in energy substrate metabolism play a key role in disease pathogenesis. Stable isotope tracing in rodent heart perfusion systems can be used to determine cardiac metabolic fluxes, namely those relative fluxes that contribute to pyruvate, the acetyl-CoA pool, and pyruvate anaplerosis, which are critical to cardiac homeostasis. Methods have previously been developed to interrogate these relative fluxes using isotopomer enrichments of measured metabolites and algebraic equations to determine a predefined metabolic flux model. However, this approach is exquisitely sensitive to measurement error, thus precluding accurate relative flux parameter determination. In this study, we applied a novel mathematical approach to determine relative cardiac metabolic fluxes using (13)C-metabolic flux analysis ((13)C-MFA) aided by multiple tracer experiments and integrated data analysis. Using (13)C-MFA, we validated a metabolic network model to explain myocardial energy substrate metabolism. Four different (13)C-labeled substrates were queried (i.e., glucose, lactate, pyruvate, and oleate) based on a previously published study. We integrated the analysis of the complete set of isotopomer data gathered from these mouse heart perfusion experiments into a single comprehensive network model that delineates substrate contributions to both pyruvate and acetyl-CoA pools at a greater resolution than that offered by traditional methods using algebraic equations. To our knowledge, this is the first rigorous application of (13)C-MFA to interrogate data from multiple tracer experiments in the perfused heart. We anticipate that this approach can be used widely to study energy substrate metabolism in this and other similar biological systems. Copyright © 2016 the American Physiological Society.

  8. CHANGES IN HEART RATE, HEART RATE VARIABILITY AND QT INTERVAL IN WOMEN WITH RHEUMATOID ARTHRITIS DURING RITUXIMAB TREATMENT

    Directory of Open Access Journals (Sweden)

    D. S. Novikova

    2014-01-01

    Full Text Available Rheumatoid arthritis (RA is a proven high cardiovascular risk disease. High heart rate (HR, lower heart rate variabil- ity (HRV, and increased QT interval are considered as predictors of cardiovascular events in patients with coronary heart disease, chronic heart failure, and diabetes mellitus. In RA, there is a pronounced rise in HR, a reduction in HRV, and an increase in QT interval mainly due to the factors reflecting the severity of the disease. Rituximab (RTM is successfully used to treat patients with high RA activity. At the same time there are only a few pieces of evidence for the effect of the drug on the cardiovascular system. Objective: to study changes in HR, HRV, and QT interval values obtained during electrocardiography (ECG Holter monitoring (ECG HM in RTM-treated women during a 6-month follow-up. Subjects and methods: The investigation enrolled 55 women (mean age 50 years with a definite diagnosis of RA and its high activity. The patients were examined 6 months after administration of RTM. The latter was infused intra- venously twice (500 and 1000 mg in 22% and 78% of the patients, respectively during therapy with disease-modifying antirheumatic and non-steroidal anti-inflammatory drugs and glucocorticoids. The RA patients were divided into two groups: 1 a satisfactory/good effect of RTM according to the EULAR criteria (n = 41; 2 no effect (n = 14. Analysis of 24-hour ECG HM yielded the values of HR and mean duration of corrected QT interval (QTc. The tim- ing HRV values obtained at ECG HM were standardized from age and mean HR (SDNNn, RMSSDn, and pNN50n. Results. The baseline HRmin and HRmean values were higher and SDNNn was lower in the RA patients in Group 1 than those in Group 2 (p < 0.05. In Group 1, RTM therapy was accompanied by a reduction in HRmean and HRmin by 8% and by an increase in SDNNn by 3%, RMSSDn by 26%, and pNN50n by 33% whereas no significant changes in HR and HRV were found in Group 2. The RTM therapy

  9. Using Complexity Metrics With R-R Intervals and BPM Heart Rate Measures

    DEFF Research Database (Denmark)

    Wallot, Sebastian; Fusaroli, Riccardo; Tylén, Kristian

    2013-01-01

    Lately, growing attention in the health sciences has been paid to the dynamics of heart rate as indicator of impending failures and for prognoses. Likewise, in social and cognitive sciences, heart rate is increasingly employed as a measure of arousal, emotional engagement and as a marker...... of interpersonal coordination. However, there is no consensus about which measurements and analytical tools are most appropriate in mapping the temporal dynamics of heart rate and quite different metrics are reported in the literature. As complexity metrics of heart rate variability depend critically......-of-concept, we employ a simple rest-exercise-rest task and show that non-linear statistics – fractal (DFA) and recurrence (RQA) analyses – reveal information about heart beat activity above and beyond the simple level of heart rate. Non-linear statistics unveil sustained post-exercise effects on heart rate...

  10. Heart Rate Variability Analysis Using Threshold of Wavelet Package Coefficients

    CERN Document Server

    Kheder, G; Massoued, M Ben; Samet, M

    2009-01-01

    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.

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

    Science.gov (United States)

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

    2014-12-01

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

  12. Heart rate variability analysis with the R package RHRV

    CERN Document Server

    García Martínez, Constantino Antonio; Vila, Xosé A; Lado Touriño, María José; Rodríguez-Liñares, Leandro; Rodríguez Presedo, Jesús María; Méndez Penín, Arturo José

    2017-01-01

    This book introduces readers to the basic concepts of Heart Rate Variability (HRV) and its most important analysis algorithms using a hands-on approach based on the open-source RHRV software. HRV refers to the variation over time of the intervals between consecutive heartbeats. Despite its apparent simplicity, HRV is one of the most important markers of the autonomic nervous system activity and it has been recognized as a useful predictor of several pathologies. The book discusses all the basic HRV topics, including the physiological contributions to HRV, clinical applications, HRV data acquisition, HRV data manipulation and HRV analysis using time-domain, frequency-domain, time-frequency, nonlinear and fractal techniques. Detailed examples based on real data sets are provided throughout the book to illustrate the algorithms and discuss the physiological implications of the results. Offering a comprehensive guide to analyzing beat information with RHRV, the book is intended for masters and Ph.D. students in v...

  13. Heart rate variability monitoring and assessment system on chip.

    Science.gov (United States)

    Massagram, Wansuree; Boric-Lubecke, Olga; Macchiarulo, Luca; Chen, Mingqi

    2005-01-01

    This paper describes a system on a chip for heart rate variability monitoring and assessment. The system design applies digital techniques to measure RR intervals from ECG signals, then categorizes and stores HRV measures in an internal memory. The system has been tested for functionality, synthesized and laid out in a 0.5 μm CMOS technology in a 3x3 mm2chip with less than 1.5 μW power dissipation. The chip detects all R peaks with millisecond accuracy after the initial 2 seconds of data, and stores up to 2 minutes of continuous ECG data and up to 4 minutes of HRV histogram. Compact size, low cost, and low power consumption make this chip suitable for employment in modern implantable and portable devices.

  14. Heart rate variability dynamics for the prognosis of cardiovascular risk.

    Directory of Open Access Journals (Sweden)

    Juan F Ramirez-Villegas

    Full Text Available Statistical, spectral, multi-resolution and non-linear methods were applied to heart rate variability (HRV series linked with classification schemes for the prognosis of cardiovascular risk. A total of 90 HRV records were analyzed: 45 from healthy subjects and 45 from cardiovascular risk patients. A total of 52 features from all the analysis methods were evaluated using standard two-sample Kolmogorov-Smirnov test (KS-test. The results of the statistical procedure provided input to multi-layer perceptron (MLP neural networks, radial basis function (RBF neural networks and support vector machines (SVM for data classification. These schemes showed high performances with both training and test sets and many combinations of features (with a maximum accuracy of 96.67%. Additionally, there was a strong consideration for breathing frequency as a relevant feature in the HRV analysis.

  15. Robustness and perturbation in the modeled cascade heart rate variability

    Science.gov (United States)

    Lin, D. C.

    2003-03-01

    In this study, numerical experiments are conducted to examine the robustness of using cascade to describe the multifractal heart rate variability (HRV) by perturbing the hierarchical time scale structure and the multiplicative rule of the cascade. It is shown that a rigid structure of the multiple time scales is not essential for the multifractal scaling in healthy HRV. So long as there exists a tree structure for the multiplication to take place, a multifractal HRV and related properties can be captured by using the cascade. But the perturbation of the multiplicative rule can lead to a qualitative change. In particular, a multifractal to monofractal HRV transition can result after the product law is perturbed to an additive one at the fast time scale. We suggest that this explains the similar HRV scaling transition in the parasympathetic nervous system blockade.

  16. Algorithms for Computerized Fetal Heart Rate Diagnosis with Direct Reporting

    Directory of Open Access Journals (Sweden)

    Kazuo Maeda

    2015-06-01

    Full Text Available Aims: Since pattern classification of fetal heart rate (FHR was subjective and enlarged interobserver difference, objective FHR analysis was achieved with computerized FHR diagnosis. Methods: The computer algorithm was composed of an experts’ knowledge system, including FHR analysis and FHR score calculation, and also of an objective artificial neural network system with software. In addition, a FHR frequency spectrum was studied to detect ominous sinusoidal FHR and the loss of baseline variability related to fetal brain damage. The algorithms were installed in a central-computerized automatic FHR monitoring system, which gave the diagnosis rapidly and directly to the attending doctor. Results: Clinically perinatal mortality decreased significantly and no cerebral palsy developed after introduction of the centralized system. Conclusion: The automatic multichannel FHR monitoring system improved the monitoring, increased the objectivity of FHR diagnosis and promoted clinical results.

  17. Effect of atrioventricular conduction on heart rate variability

    KAUST Repository

    Ahmad, Talha Jamal

    2011-08-01

    This paper discusses the effect of atrioventricular conduction time (AVCT) on the short-term Heart Rate Variability (HRV) by computing HRV parameters using intervals between the onsets of successive P waves (PP time series) for three groups: normal, arrhythmia and sudden cardiac death (SCD) patients. A very precise wavelet transform based ECG delineator was developed to detect PP, PR and RR time series. Mean PR variation in arrhythmia and SCD group was found to be significantly high as compared to the normal group. It was observed that when PR variations in arrhythmia and SCD cases crossed a certain threshold, RR variability no longer provided a very accurate estimate of HRV. In such cases, PP variability was able to provide a better assessment of HRV. © 2011 IEEE.

  18. What is the “normal” fetal heart rate?

    Directory of Open Access Journals (Sweden)

    Stephanie Pildner von Steinburg

    2013-06-01

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

  19. Exercise training improves heart rate variability after methamphetamine dependency.

    Science.gov (United States)

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

    2014-06-01

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

  20. [Heart rate recovery after exercise in subjects undergoing cardiologic rehabilitation].

    Science.gov (United States)

    Mejer, Anna; Urzedowicz, Beata; Rembek-Wieliczko, Magdalena; Koziróg, Marzena; Ciećwierz, Julita; Kowalski, Jan

    2012-12-01

    Research indicates that slow heart rate recovery 1-2 minutes after exercise is a predictor of cardiovascular mortality, sudden mortality as well. It is hardly related to myocardial ischemia; most of all, it is related to impaired activities of the parasympathetic system. The purpose of this study was to assess HRR in subjects after a surgical treatment (percutaneous coronary intervention - PCI) of acute coronary syndromes (ACS), undergoing cardiologic rehabilitation. The study comprised 58 subjects, 42 men and 16 women aged 49-68 (56.8 +/- 7.6) after ACS treated with PCI undergoing cardiologic rehabilitation (stage 2)--group I. The comparative group comprised 34 subjects, 25 men and 9 women aged 46-61 (55.5 +/- 8.9 lat) who were clinically healthy and who underwent a single sub-maximal exercise test--group II. In subjects undergoing rehabilitation, an exercise test was performed twice --before and after stage 2 of rehabilitation. HRR was defined as a difference between the peak heart rate and those after the 1st (HRR1) and 2nd (HRR) minute of recovery. After stationary rehabilitation as a part of stage 2 of cardiologic rehabilitation, HRR2 was 26.3 +/- 10.6/min and was 40.8/min +/- 13.8/min; both these values were not significantly different from values observed in healthy subjects (p > 0.05). Significant increase in HRR1 and HRR2 was observed after the completion of stage 2 of cardiologic rehabilitation in ill subjects (p < 0.05) as compared to initial values. In subjects after ACS treated with PCI, it is observed that HRR changes back to normal values observed in healthy subjects as a result of underwent cardiologic rehabilitation. HRR should become an important factor in assessing effectiveness of conducted cardiologic rehabilitation.

  1. Cuff inflation during ambulatory blood pressure monitoring and heart rate

    Directory of Open Access Journals (Sweden)

    Mia Skov-Madsen

    2008-11-01

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

  2. The effects of baseline heart rate recovery normality and exercise training protocol on heart rate recovery in patients with heart failure.

    Science.gov (United States)

    Yaylalı, Yalın Tolga; Fındıkoğlu, Gülin; Yurtdaş, Mustafa; Konukçu, Sibel; Şenol, Hande

    2015-09-01

    It is unclear which exercise training protocol yields superior heart rate recovery (HRR) improvement in heart failure (HF) patients. Whether baseline HRR normality plays a role in the improvement is unknown. We hypothesized that an exercise training protocol and baseline HRR normality would be factors in altering HRR in HF patients. In this prospective, randomized, controlled and 3 group parallel study, 41 stable HF patients were randomly assigned to 3-times-weekly training sessions for 12 weeks, consisting of i) 30 minutes of interval training (IT) (n=17, 63.7±8.8 years old) versus ii) 30 minutes of continuous training (CT) (n=13, 59.6±6.8 years old) versus iii) no training (CON) (n=11, 60.6±9.9 years old). Each patient had cardiopulmonary exercise testing before and after the training program. Maximum heart rates attained during the test and heart rates at 1 and 2 min (HRR1 and HRR2) during the recovery phase were recorded. Paired samples t-test or Wilcoxon signed-rank test was used for comparisons before and after training. One-way ANOVA or Kruskal-Wallis variance analysis was used for comparisons among groups. HRR1 was unchanged after training. HRR2 improved in the IT group after training, and post-training HRR2 values were significantly faster in the IT group than in controls. Both HRR1 and HRR2 was significantly faster, irrespective of exercise protocol in patients with abnormal baseline values after training. HRR1 did not improve after training. HRR2 improved only in the IT group. Both HRRs in patients with abnormal baseline values improved after both exercise protocols. IT might be superior to CT in improving HRR2. Baseline HRR might play a role in its response to exercise.

  3. The predictive value of resting heart rate following osmotherapy in brain injury: back to basics

    Directory of Open Access Journals (Sweden)

    Hasanpour Mir Mahsa

    2012-12-01

    Full Text Available Abstract Background The importance of resting heart rate as a prognostic factor was described in several studies. An elevated heart rate is an independent risk factor for adverse cardiovascular events and total mortality in patients with coronary artery disease, chronic heart failure, and the general population. Also heart rate is elevated in the Multi Organ Dysfunction Syndrome (MODS and the mortality due to MODS is highly correlated with inadequate sinus tachycardia. To evaluate the value of resting heart rate in predicting mortality in patients with traumatic brain injury along scoring systems like Acute Physiology and Chronic Health Evaluation(APACHE II, Sequential Organ Failure Assessment (SOFA and Glasgow Coma Score (GCS. Method By analyzing data which was collected from an open labeled randomized clinical trial that compared the different means of osmotherapy (mannitol vs bolus or infusion hypertonic saline, heart rate, GCS, APACHE II and SOFA score were measured at baseline and daily for 7 days up to 60 days and the relationship between elevated heart rate and mortality during the first 7 days and 60th day were assessed. Results After adjustments for confounding factors, although there was no difference in mean heart rate between either groups of alive and expired patients, however, we have found a relative correlation between 60th day mortality rate and resting heart rate (P=0.07. Conclusion Heart rate can be a prognostic factor for estimating mortality rate in brain injury patients along with APACHE II and SOFA scores in patients with brain injury.

  4. RELATION BETWEEN SEVERITY OF DISEASE AND IMPAIRMENT OF HEART-RATE-VARIABILITY PARAMETERS IN PATIENTS WITH CHRONIC CONGESTIVE-HEART-FAILURE SECONDARY TO CORONARY-ARTERY DISEASE

    NARCIS (Netherlands)

    SZABO, BM; VANVELDHUISEN, DJ; BROUWER, J; HAAKSMA, J; LIE, KI

    1995-01-01

    Correlations between New York Heart Association functional class, left ventricular ejection fraction, and peak oxygen consumption were compared to heart rate variability and analyzed in 79 heart failure patients with left ventricular ejection fraction

  5. Good at Heart: Preserving Cardiac Metabolism during aging.

    Science.gov (United States)

    Sorriento, Daniela; Franco, Antonietta; Rusciano, Maria Rosaria; Maione, Angela Serena; Soprano, Maria; Illario, Maddalena; Iaccarino, Guido; Ciccarelli, Michele

    2015-01-01

    The natural process of aging determinates several cardiac modifications with increased susceptibility to heart diseases and ultimately converging on development of chronic heart failure as final stage. These changes mainly include left ventricular hypertrophy, diastolic dysfunction, valvular degeneration, increased cardiac fibrosis, increased prevalence of atrial fibrillation, and decreased maximal exercise capacity, as demonstrated in several humans and animal models of aging. While different theories have been proposed to explain the natural process of aging, it is clear that most of the alterations affect mechanisms involved in cell homeostasis and maintenance. Latest research studies have in particular focused on role of mitochondrial oxidative stress, energy production and mitochondria quality control. This article reviews the central role played by this organelle in aging and the role of new molecular players involved into the progression toward heart failure and potentially susceptible of new "anti-aging" strategies.

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

    Science.gov (United States)

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

    2014-03-01

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

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

    CERN Document Server

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

    2015-01-01

    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...

  8. Heart rate control with adrenergic blockade: Clinical outcomes in cardiovascular medicine

    Science.gov (United States)

    Feldman, David; Elton, Terry S; Menachemi, Doron M; Wexler, Randy K

    2010-01-01

    The sympathetic nervous system is involved in regulating various cardiovascular parameters including heart rate (HR) and HR variability. Aberrant sympathetic nervous system expression may result in elevated HR or decreased HR variability, and both are independent risk factors for development of cardiovascular disease, including heart failure, myocardial infarction, and hypertension. Epidemiologic studies have established that impaired HR control is linked to increased cardiovascular morbidity and mortality. One successful way of decreasing HR and cardiovascular mortality has been by utilizing β-blockers, because their ability to alter cell signaling at the receptor level has been shown to mitigate the pathogenic effects of sympathetic nervous system hyperactivation. Numerous clinical studies have demonstrated that β-blocker-mediated HR control improvements are associated with decreased mortality in postinfarct and heart failure patients. Although improved HR control benefits have yet to be established in hypertension, both traditional and vasodilating β-blockers exert positive HR control effects in this patient population. However, differences exist between traditional and vasodilating β-blockers; the latter reduce peripheral vascular resistance and exert neutral or positive effects on important metabolic parameters. Clinical evidence suggests that attainment of HR control is an important treatment objective for patients with cardiovascular conditions, and vasodilating β-blocker efficacy may aid in accomplishing improved outcomes. PMID:20539841

  9. [The exercise training restores the heart rate variability in heart failure patients. A systematic review].

    Science.gov (United States)

    Segovia, Victoria; Manterola, Carlos; González, Marcelo; Rodríguez-Núñez, Iván

    2017-01-05

    Cardiovascular diseases are an important cause of morbidity and mortality in the general population. In this sense the autonomic imbalance is the cornerstone of the physiopathology underlying the development of these diseases. The aim of this study was to determine the efficacy of exercise training on heart rate variability (HRV) in adult patients with chronic heart failure. A systematic literature review was conducted on electronic databases. The considered studies were randomized clinical trials, quasi-experimental studies with non-randomized control group, quasi-experimental studies with analysis of pre and post intervention and crossover studies with randomly assigned training and detraining periods. The standardized mean differences were calculated between pre and post intervention in both control and experimental group. Intra-subject analysis of control group showed no statistical significance in the standardized mean differences of HRV. In the experimental group, the standardized mean differences were positive for the root mean square of successive difference (+0.468±0.215; P=.032), high frequency band (HF) (0.934±0.256; P<.001) and low frequency band (LF) (<0.415±0.096; P=.001). Moreover, the standardized mean difference was negative for LF/HF (-0.747±0.369, P=<.044). On the other hands, only 3 studies entered the meta-analysis of comparative studies. The effect of exercise training was favorable for experimental group in LF/HF (-2.21±95% CI: -3.83 to -0.60), HF and LF. The exercise training was effective in augmenting HRV and restores autonomic balance in patients with heart failure. Copyright © 2016 Instituto Nacional de Cardiología Ignacio Chávez. Publicado por Masson Doyma México S.A. All rights reserved.

  10. Pharmacoeconomic analysis of heart rate slowing drugs in patients with ischemic heart disease

    Directory of Open Access Journals (Sweden)

    E. I. Tarlovskaya

    2016-01-01

    Full Text Available Aim. To compare the efficacy and cost/effectiveness ratio of the original and generic bisoprolol in achieving target heart rate (HR in patients with ischemic heart disease.Material and methods. Patients with ischemic heart disease (n=60; 36 males and 24 females aged from 35 to 75 years were included into the study. Patients were randomized into group A (received therapy based on the original bisoprolol or into group B (received therapy based on of generic bisoprolol. Ivabradine was added, if the effect was insufficient. The duration of follow-up was 6 weeks. The HR dynamics was assessed during the study period. Cost/effectiveness ratio was calculated.Results. Significant HR slowing was found in both groups by the end of observation. In group A baseline HR was 70.0±5.6 beats/min and in 6 weeks - 58.1±3.8 beats/min, while in group B - 69.5±5.2 and 60.5±3.9 beats/min respectively. HR slowing was significantly higher in group A than that in group B. Direct costs in order to achieve a target HR in 1 patient for 6 weeks of therapy in group A were 663.75 rubles, while this in group B - 1093.58 rubles. Direct costs for HR deceleration by 1 beat in group A were 48.46 rubles vs 69.40 rubles in group B. The effect of therapy based on the original bisoprolol, is superior to that when generic bisoprolol used.Conclusion. HR-slowing effect of therapy based on the original bisoprolol was superior to that when generic bisoprolol was used. Pharmacoeconomic analysis revealed that HR deceleration was more economically profitable in treatment based on the original bisoprolol.

  11. Heart Rate Variability and the Efficacy of Biofeedback in Heroin Users with Depressive Symptoms

    OpenAIRE

    Lin, I-Mei; Ko, Jiun-Min; Fan, Sheng-Yu; YEN, CHENG-FANG

    2016-01-01

    Objective Low heart rate variability (HRV) has been confirmed in heroin users, but the effects of heart-rate-variability–biofeedback in heroin users remain unknown. This study examined (1) correlations between depression and HRV indices; (2) group differences in HRV indices among a heroin-user group, a group with major depressive disorder but no heroin use, and healthy controls; and (3) the effects of heart-rate-variability–biofeedback on depressive symptoms, HRV indices, and respiratory rate...

  12. Left ventricular dimensions and systolic function during spontaneous heart rate changes: an echocardiographic study.

    Science.gov (United States)

    Bett, J H; Dryburgh, L

    1981-06-01

    We examined the relationships between spontaneous heart rate (or conversely cycle length) changes and left ventricular diastolic dimensions and indices of systolic function in twenty-three subjects. In most there was clearly an inverse relationship between rate and these indices and nearly always a positive correlation between performance and end-diastolic dimension. Previously described relationship between heart rate and mean velocity of circumferential fiber shortening are applicable only when the heart rate is constant.

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

    Science.gov (United States)

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

    1996-12-01

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

  14. Variability in heart rate recovery measurements over 1 year in healthy, middle-aged adults.

    Science.gov (United States)

    Mellis, M G; Ingle, L; Carroll, S

    2014-02-01

    This study assessed the longer-term (12-month) variability in post-exercise heart rate recovery following a submaximal exercise test. Longitudinal data was analysed for 97 healthy middle-aged adults (74 male, 23 female) from 2 occasions, 12 months apart. Participants were retrospectively selected if they had stable physical activity habits, submaximal treadmill fitness and anthropometric measurements between the 2 assessment visits. A submaximal Bruce treadmill test was performed to at least 85% age-predicted maximum heart rate. Absolute heart rate and Δ heart rate recovery (change from peak exercise heart rate) were recorded for 1 and 2 min post-exercise in an immediate supine position. Heart rate recovery at both time-points was shown to be reliable with intra-class correlation coefficient values ≥ 0.714. Absolute heart rate 1-min post-exercise showed the strongest agreement between repeat tests (r = 0.867, P heart rate values rather than Δ heart rate recovery, and for 1-min rather than 2-min post-exercise recovery time points. Log-transformed values generated better variability with acceptable coefficient of variation for all measures (2.2-10%). Overall, 1 min post-exercise heart rate recovery data had least variability over the 12-month period in apparently healthy middle-aged adults. © Georg Thieme Verlag KG Stuttgart · New York.

  15. Cardiac energy metabolic alterations in pressure overload–induced left and right heart failure (2013 Grover Conference Series)

    OpenAIRE

    Sankaralingam, Sowndramalingam; Gary D Lopaschuk

    2015-01-01

    Pressure overload of the heart, such as seen with pulmonary hypertension and/or systemic hypertension, can result in cardiac hypertrophy and the eventual development of heart failure. The development of hypertrophy and heart failure is accompanied by numerous molecular changes in the heart, including alterations in cardiac energy metabolism. Under normal conditions, the high energy (adenosine triphosphate [ATP]) demands of the heart are primarily provided by the mitochondrial oxidation of fat...

  16. THE INFLUENCE OF METABOLIC SYNDROME ON HEART ABNORMALITIES IN PATIENTS WITH ARTERIAL HYPERTENSION

    Directory of Open Access Journals (Sweden)

    G. Kh. Sharipova

    2015-01-01

    Full Text Available Aim: To evaluate structural and functional heart abnormalities in patients with arterial hypertension (AH with and without metabolic syndrome.Materials and methods: The study included 303  patients with AH I, II and III, aged from 25 to  70  years (mean±SD 52±18 years. All patients were categorized into 3 groups according to severity of AH (AH I, II and III corresponded to groups 1, 2 and 3, respectively. Within each group, patients were subdivided into 2 subgroups: without metabolic syndrome (n=151 and with metabolic syndrome (n=152. Assessments included measurements of blood glucose and lipids, 24-hour monitoring of blood pressure, echocardiography with calculation of myocardial mass index of left ventricle and the use of conventional and tissue myocardial dopplerography.Results: Already at early stage of AH (gr. I, 60% patients with metabolic syndrome and 32% patients without metabolic abnormalities had some degree of left ventricular remodeling, including concentric type of remodeling in 12 and 20%, excentric hypertrophy in 18 and 6%, concentric left ventricular hypertrophy in 30 and 6%, respectively. In AH I, an increase of myocardial mass index of left ventricle was found in 39% of patients with metabolic syndrome and in 12% patients without it. In patients with AH I, abnormalities of left ventricular diastolic function according to the results of tissue myocardial dopplerography was seen in 82% of patients with metabolic syndrome and in 42% of patients without metabolic syndrome. Patients with AH I–III and metabolic syndrome had almost 5-fold higher probability of heart abnormalities than AH patients without metabolic disturbances (odds ratio 4.8, 95% confidence interval 1.9–6.4, p< 50 and>50 years.Conclusion: Metabolic syndrome contributes to heart abnormalities irrespective of gender, age and AH grade. 

  17. Influence of increased heart rate and aortic pressure on resting indices of functional coronary stenosis severity.

    Science.gov (United States)

    Casadonte, Lorena; Verhoeff, Bart-Jan; Piek, Jan J; VanBavel, Ed; Spaan, Jos A E; Siebes, Maria

    2017-09-13

    Baseline assessment of functional stenosis severity has been proposed as a practical alternative to hyperemic indices. However, intact autoregulation mechanisms may affect intracoronary hemodynamics. The aim of this study was to investigate the effect of changes in aortic pressure (Pa) and heart rate (HR) on baseline coronary hemodynamics and functional stenosis assessment. In 15 patients (55 ± 3% diameter stenosis) Pa, intracoronary pressure (Pd) and flow velocity were obtained at control, and during atrial pacing at 120 bpm, increased Pa (+30 mmHg) with intravenous phenylephrine (PE), and elevated Pa while pacing at sinus heart rate (PE + sHR). We derived rate pressure product (RPP = systolic Pa × HR), baseline microvascular resistance (BMR = Pd/velocity), and stenosis resistance [BSR = (Pa - Pd)/velocity] as well as whole-cycle Pd/Pa. Tachycardia (120 ± 1 bpm) raised RPP by 74% vs. Accordingly, BMR decreased by 27% (p stenosis severity, causing Pd/Pa and BSR of borderline lesions to cross the diagnostic threshold. In conclusion, coronary microvascular adaptation to physiological conditions affecting metabolic demand at rest influences intracoronary hemodynamics, which may lead to altered basal stenosis indices used for clinical decision-making.

  18. Discovery of novel heart rate-associated loci using the Exome Chip

    DEFF Research Database (Denmark)

    van den Berg, Marten E; Warren, Helen R; Cabrera, Claudia P

    2017-01-01

    to discover new genetic loci associated with heart rate from Exome Chip meta-analyses.Heart rate was measured from either elecrtrocardiograms or pulse recordings. We meta-analysed heart rate association results from 104 452 European-ancestry individuals from 30 cohorts, genotyped using the Exome Chip. Twenty...... long-range regulatory chromatin interactions in heart tissue (SCD, SLF2 and MAPK8). We observed significant enrichment in DNase I hypersensitive sites in fetal heart and lung. Moreover, enrichment was seen for the first time in human neuronal progenitor cells (derived from embryonic stem cells...

  19. Clinic and ambulatory heart rates in patients with ischaemic heart disease and/or chronic heart failure taking rate-limiting medications: are they interchangeable?

    Science.gov (United States)

    Javed, Omar; Koo, Kenneth; El-Omar, Omar; Allen, Stuart; Squires, Alexander; El-Omar, Magdi

    2015-01-01

    The prognostic benefit from heart rate (HR) reduction in patients with ischaemic heart disease (IHD) and/or chronic heart failure (CHF) is now firmly established. Most decisions regarding initiation and/or dose adjustment of HR-limiting medications in such patients are based on clinic HR. Yet, this is a highly variable parameter that may not necessarily reflect HR control over the 24 h period. To examine the level of agreement between mean clinic and mean ambulatory HRs in patients with IHD and/or CHF taking rate-limiting medications. Prospective, observational study. Fifty patients with IHD and/or CHF who attended cardiology outpatient clinics at the Manchester Heart Centre and underwent same-day 24 h continuous ECG recording between March and October 2013 were included in the study. Mean clinic HR was compared with mean 24 h, daytime and night-time HRs. Limits-of-agreement plots were constructed to examine the relationship between the two HR measures in more detail. The mean clinic HR was numerically similar to the mean HRs of all ambulatory time periods examined. However, on Bland-Altman plots, the limits of agreement between clinic and ambulatory HR means were quite wide, with the mean clinic HR ranging between 10.93 and 13.58 bpm below and 8.4 and 18.15 bpm above the mean ambulatory HR. Although numerically similar, the means of clinic and ambulatory HRs in patients with IHD and/or CHF display wide limits of agreement. As such, the two measures cannot be regarded as interchangeable. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  20. Metabolism: flow and contractility of the Langendorff heart

    NARCIS (Netherlands)

    H. Stam (Hans)

    1978-01-01

    textabstractThis thesis reviews current literature and describes experimental studies on the regulation and modification of coronary flow and contractility in isolated rat hearts. In chapter I and introduction is given to the problems of fatty acid toxicity and myocardial function. Coronary flow