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Sample records for volume heart rate

  1. Heart Rate and Increased Intravascular Volume

    Czech Academy of Sciences Publication Activity Database

    Souček, M.; Kára, T.; Jurák, Pavel; Halámek, Josef; Špinarová, L.; Meluzín, J.; Toman, J.; Řiháček, I.; Šumbera, J.; Fráňa, P.

    2003-01-01

    Roč. 52, - (2003), s. 137 - 140 ISSN 0862-8408 R&D Projects: GA ČR GA102/02/1339 Institutional research plan: CEZ:AV0Z2065902 Keywords : kidneys * heart rate * atrial mechanisms Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery Impact factor: 0.939, year: 2003

  2. Small-volume amnioinfusion: a potential stimulus of intrapartum fetal heart rate accelerations.

    Science.gov (United States)

    Wax, Joseph R; Flaherty, Nina; Pinette, Michael G; Blackstone, Jacquelyn; Cartin, Angelina

    2004-02-01

    We describe a recurrent nonreassuring fetal heart rate pattern in which small-volume amnioinfusions apparently evoked fetal heart rate accelerations suggested fetal well-being, allowing that progressive labor that culminated in the vaginal delivery of a healthy infant.

  3. Changes in extracellular muscle volume affect heart rate and blood pressure responses to static exercise

    Science.gov (United States)

    Baum, K.; Essfeld, D.; Stegemann, J.

    To investigate the effect of μg-induced peripheral extracellular fluid reductions on heart rate and blood pressure during isometric exercise, six healthy male subjects performed three calf ergometer test with different extracellular volumes of working muscles. In all tests, body positions during exercise were identical (supine with the knee joint flexed to 900). After a pre-exercise period of 25 min, during which calf volumes were manipulated, subjects had to counteract an external force of 180 N for 5 min. During the pre-exercise period three different protocols were applied. Test A: Subjects rested in the exercise position; test B: Body position was the same as in A but calf volume was increased by venous congestion (cuffs inflated to 80 mm Hg); test C: Calf volumes were decreased by a negative hydrostatic pressure (calves about 40 cm above heart level with the subjects supine). To clamp the changed calf volumes in tests B and C, cuffs were inflated to 300 mm Hg 5 min before the onset of exercise. This occlusion was maintained until termination of exercise. Compared to tests A and B, the reduced volume of test C led to significant increases in heart rate and blood pressure during exercise. Oxygen uptake did not exceed resting levels in B and C until cuffs were deflated, indicating that exclusively calf muscles contributed to the neurogenic peripheral drive. It is concluded that changes in extracellular muscle volume have to be taken into account when comparing heart rate and blood pressure during lg- and μg- exercise.

  4. The forgotten role of central volume in low frequency oscillations of heart rate variability.

    Directory of Open Access Journals (Sweden)

    Manuela Ferrario

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

  5. The forgotten role of central volume in low frequency oscillations of heart rate variability.

    Science.gov (United States)

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

    2015-01-01

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

  6. The Effects of TM on Concurrent Heart Rate, Peripheral Blood Pulse Volume, and the Alpha Wave Frequency.

    Science.gov (United States)

    Lukas, Jerome S.

    Through observation of 26 subjects over a 3 month period, this research project measured the effects of transcendental meditation (TM) on concurrent heart rate, peripheral blood pulse volume, and the alpha wave frequency. The subjects were assigned randomly to three groups. One group practiced TM as prescribed by the International Meditation…

  7. Heart rate index

    DEFF Research Database (Denmark)

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

    1992-01-01

    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...

  8. Intraoperative stroke volume optimization using stroke volume, arterial pressure, and heart rate: closed-loop (learning intravenous resuscitator) versus anesthesiologists.

    Science.gov (United States)

    Rinehart, Joseph; Chung, Elena; Canales, Cecilia; Cannesson, Maxime

    2012-10-01

    The authors compared the performance of a group of anesthesia providers to closed-loop (Learning Intravenous Resuscitator [LIR]) management in a simulated hemorrhage scenario using cardiac output monitoring. A prospective cohort study. In silico simulation. University hospital anesthesiologists and the LIR closed-loop fluid administration system. Using a patient simulator, a 90-minute simulated hemorrhage protocol was run, which included a 1,200-mL blood loss over 30 minutes. Twenty practicing anesthesiology providers were asked to manage this scenario by providing fluids and vasopressor medication at their discretion. The simulation program was also run 20 times with the LIR closed-loop algorithm managing fluids and an additional 20 times with no intervention. Simulated patient weight, height, heart rate, mean arterial pressure, and cardiac output (CO) were similar at baseline. The mean stroke volume, the mean arterial pressure, CO, and the final CO were higher in the closed-loop group than in the practitioners group, and the coefficient of variance was lower. The closed-loop group received slightly more fluid (2.1 v 1.9 L, p closed-loop maintained more stable hemodynamics than the practitioners primarily because the fluid was given earlier in the protocol and CO optimized before the hemorrhage began, whereas practitioners tended to resuscitate well but only after significant hemodynamic change indicated the need. Overall, these data support the potential usefulness of this closed-loop algorithm in clinical settings in which dynamic predictors are not available or applicable. Published by Elsevier Inc.

  9. Physical correlates of radiologic heart volume

    International Nuclear Information System (INIS)

    Christie, D.

    1978-01-01

    Radiologic heart volume was calculated on a 10 per cent random sample of subjects examined in the London Civil Service Health Survey. Data were available for 1 188 men over the age of 40, and the importance of correcting radiologic heart volume for body size, age and heart rate was demonstrated. After these variables were taken into account, the most important association found was with blood pressure. Radiologic heart volume has potential value in cardiovascular screening programmes. (Auth.)

  10. 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...

  11. Effect of age on heart rate, blood lactate concentration, packed cell volume and hemoglobin to exercise in Jeju crossbreed horses

    Directory of Open Access Journals (Sweden)

    Ok-Deuk Kang

    2017-01-01

    Full Text Available Abstract Background This study aimed to analyze the on heart rate, blood lactate concentration, packed cell volume (PCV and hemoglobin (Hb response after conducting exercise in endurance horses. Methods A total of 20 healthy 3–9-years-old Jeju crossbreed mares (5.95 ± 2.24 year of age and 312.65 ± 13.59 kg of weight currently participating the endurance competition were used. The field tests selected for the experiment was gallop (approximately 8.3 m/s along the selected 2.5 km course (a natural forest trail, not artificial road; a closed loop course. The horses were divided into three groups according to their age; 3–4 years of age (G1, 3.29 ± 0.49 year, 6–7 years of age (G2, 6.42 ± 0.53, and 8–9 years of age (G3, 8.50 ± 0.55. The measurements times for the heart rate, blood lactate concentration, PCV, and Hb analysis were conducted before exercise (T0, shortly after exercise (T1, 15 min after exercise (T2, and 30 min after exercise (T3, respectively. Data was analyzed using an analysis of covariance (ANCOVA for repeated measures with times and groups. Results The results of the comparison depending on the passage of rest time after exercise suggest that the heart rate and blood lactate concentration of three groups at T2 significantly decreased compared to T1 (p < 0.001. PCV of the G2 and G3 groups were significantly decreased at T2 compared to T1 (p < 0.01. Hb values at G2 (p < 0.01 and G3 (p < 0.001 groups were significantly decreased at T2 as compared to T1. However, heart rate, blood lactate concentration, PCV and Hb level at T1 showed no difference in the comparison of horses from different age groups with the exception of G3 group in terms of heart rate. Conclusion The physiologic and hematological responses of horses during recovery time after 2,500 m exercise with gallop were no significant difference among the groups. These data are useful as a response evaluation method for

  12. The heart rate increase at the onset of high-work intensity exercise is accelerated by central blood volume loading.

    Science.gov (United States)

    Miyamoto, Tadayoshi; Oshima, Yoshitake; Ikuta, Komei; Kinoshita, Hiroshi

    2006-01-01

    Using a water immersion (WI) method, the combined effect of central blood volume (CBV) loading and work intensity on the time course of heart rate (HR) at the onset of upright dynamic exercise was investigated. Seven males cranked a cycle ergometer for 12 min using their un-immersed arms at low-, moderate- and high-work intensities, followed by a 12-min rest. For WI, the pre-exercise resting cardiac output increased by 36%, while HR decreased by 22% [from 76.8 (10.4) to 59.6 (9.8) beats/min]. WI also increased the high-frequency (HF, 0.15-0.40 Hz) component of the HR variability, suggesting an increased vagal activity. During the initial 2 min of the exercise period at low-work intensity, HR increased by 34.9 and 25.8% in the WI and control conditions, respectively. These were 117 and 73% at high-work intensity, indicating more accelerated HR with WI than the control. The plasma norepinephrine concentration increased less during high-work intensity exercise during WI, as compared to exercise during control conditions. In conclusion, the HR increase at the onset of high-work intensity exercise is accelerated by CBV loading but not at low intensity, possibly reflecting vago-sympathetic interaction and reduced baroreflex sensitivity.

  13. [Resonance hypothesis of heart rate variability origin].

    Science.gov (United States)

    Sheĭkh-Zade, Iu R; Mukhambetaliev, G Kh; Cherednik, I L

    2009-09-01

    A hypothesis is advanced of the heart rate variability being subjected to beat-to-beat regulation of cardiac cycle duration in order to ensure the resonance interaction between respiratory and own fluctuation of the arterial system volume for minimization of power expenses of cardiorespiratory system. Myogenic, parasympathetic and sympathetic machanisms of heart rate variability are described.

  14. Heart rate monitoring mobile applications

    OpenAIRE

    Chaudhry, Beenish M.

    2016-01-01

    Total number of times a heart beats in a minute is known as the heart rate. Traditionally, heart rate was measured using clunky gadgets but these days it can be measured with a smartphone?s camera. This can help you measure your heart rate anywhere and at anytime, especially during workouts so you can adjust your workout intensity to achieve maximum health benefits. With simple and easy to use mobile app, ?Unique Heart Rate Monitor?, you can also maintain your heart rate history for personal ...

  15. Heart rate monitoring mobile applications.

    Science.gov (United States)

    Chaudhry, Beenish M

    2016-01-01

    Total number of times a heart beats in a minute is known as the heart rate. Traditionally, heart rate was measured using clunky gadgets but these days it can be measured with a smartphone's camera. This can help you measure your heart rate anywhere and at anytime, especially during workouts so you can adjust your workout intensity to achieve maximum health benefits. With simple and easy to use mobile app, 'Unique Heart Rate Monitor', you can also maintain your heart rate history for personal reflection and sharing with a provider.

  16. Target Heart Rates

    Science.gov (United States)

    ... Check Recipe Certification Program Nutrition Requirements Heart-Check Professional Resources Contact the Heart-Check Certification Program Simple Cooking and Recipes Dining Out Choosing a Restaurant Deciphering ...

  17. Neonatal heart rate prediction.

    Science.gov (United States)

    Abdel-Rahman, Yumna; Jeremic, Aleksander; Tan, Kenneth

    2009-01-01

    Technological advances have caused a decrease in the number of infant deaths. Pre-term infants now have a substantially increased chance of survival. One of the mechanisms that is vital to saving the lives of these infants is continuous monitoring and early diagnosis. With continuous monitoring huge amounts of data are collected with so much information embedded in them. By using statistical analysis this information can be extracted and used to aid diagnosis and to understand development. In this study we have a large dataset containing over 180 pre-term infants whose heart rates were recorded over the length of their stay in the Neonatal Intensive Care Unit (NICU). We test two types of models, empirical bayesian and autoregressive moving average. We then attempt to predict future values. The autoregressive moving average model showed better results but required more computation.

  18. Effects of Liraglutide on Heart Rate and Heart Rate Variability

    DEFF Research Database (Denmark)

    Kumarathurai, Preman; Anholm, Christian; Larsen, Bjørn Strøier

    2017-01-01

    OBJECTIVE: Reduced heart rate variability (HRV) and increased heart rate (HR) have been associated with cardiovascular mortality. Glucagon-like peptide 1 receptor agonists (GLP-1 RAs) increase HR, and studies have suggested that they may reduce HRV. We examined the effect of the GLP-1 RA...

  19. Variation in critical care unit admission rates and outcomes for patients with acute coronary syndromes or heart failure among high- and low-volume cardiac hospitals.

    Science.gov (United States)

    van Diepen, Sean; Bakal, Jeffrey A; Lin, Meng; Kaul, Padma; McAlister, Finlay A; Ezekowitz, Justin A

    2015-02-27

    Little is known about cross-hospital differences in critical care units admission rates and related resource utilization and outcomes among patients hospitalized with acute coronary syndromes (ACS) or heart failure (HF). Using a population-based sample of 16,078 patients admitted to a critical care unit with a primary diagnosis of ACS (n=14,610) or HF (n=1467) between April 1, 2003 and March 31, 2013 in Alberta, Canada, we stratified hospitals into high (>250), medium (200 to 250), or low (<200) volume based on their annual volume of all ACS and HF hospitalization. The percentage of hospitalized patients admitted to critical care units varied across low, medium, and high-volume hospitals for both ACS and HF as follows: 77.9%, 81.3%, and 76.3% (P<0.001), and 18.0%, 16.3%, and 13.0% (P<0.001), respectively. Compared to low-volume units, critical care patients with ACS and HF admitted to high-volume hospitals had shorter mean critical care stays (56.6 versus 95.6 hours, P<0.001), more critical care procedures (1.9 versus 1.2 per patient, <0.001), and higher resource-intensive weighting (2.8 versus 1.5, P<0.001). No differences in in-hospital mortality (5.5% versus 6.2%, adjusted odds ratio 0.93; 95% CI, 0.61 to 1.41) were observed between high- and low-volume hospitals; however, 30-day cardiovascular readmissions (4.6% versus 6.8%, odds ratio 0.77; 95% CI, 0.60 to 0.99) and cardiovascular emergency-room visits (6.6% versus 9.5%, odds ratio 0.80; 95% CI, 0.69 to 0.94) were lower in high-volume compared to low-volume hospitals. Outcomes stratified by ACS or HF admission diagnosis were similar. Cardiac patients hospitalized in low-volume hospitals were more frequently admitted to critical care units and had longer hospitals stays despite lower resource-intensive weighting. These findings may provide opportunities to standardize critical care utilization for ACS and HF patients across high- and low-volume hospitals. © 2015 The Authors. Published on behalf of the American

  20. Tachycardia | Fast Heart Rate

    Science.gov (United States)

    ... may recommend or try: Carotid sinus massage: gentle pressure on the neck, where the carotid artery splits into two branches. Must be performed by a healthcare professional to minimize risk of stroke, heart or lung injury from blood clots. Pressing gently on the eyeballs ...

  1. Blood Pressure vs. Heart Rate

    Science.gov (United States)

    ... Peripheral Artery Disease Venous Thromboembolism Aortic Aneurysm More Blood Pressure vs. Heart Rate (Pulse) Updated:Nov 13,2017 ... This content was last reviewed October 2016. High Blood Pressure • Home • Get the Facts About HBP Introduction What ...

  2. 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.

  3. The effect of endogenously released glucose, insulin, glucagon-like peptide 1, ghrelin on cardiac output, heart rate, stroke volume, and blood pressure.

    Science.gov (United States)

    Hlebowicz, Joanna; Lindstedt, Sandra; Björgell, Ola; Dencker, Magnus

    2011-12-29

    Ingestion of a meal increases the blood flow to the gastrointestinal organs and affects the heart rate (HR), blood pressure and cardiac output (CO), although the mechanisms are not known. The aim of this study was to evaluate the effect of endogenously released glucose, insulin, glucagon-like peptide 1 (GLP-1), ghrelin on CO, HR, stroke volume (SV), and blood pressure. Eleven healthy men and twelve healthy women ((mean ± SEM) aged: 26 ± 0.2 y; body mass index: 21.8 ± 0.1 kg/m(2))) were included in this study. The CO, HR, SV, systolic and diastolic blood pressure, antral area, gastric emptying rate, and glucose, insulin, GLP-1 and ghrelin levels were measured. The CO and SV at 30 min were significantly higher, and the diastolic blood pressure was significantly lower, than the fasting in both men and women (P blood pressure (P = 0.021, r = -0.681), and the change in SV (P = 0.008, r = -0.748) relative to the fasting in men. The insulin 0-30 min AUC was significantly correlated to the CO 0-30 min AUC (P = 0.002, r = 0.814) in men. Significant correlations were also found between the 0-120 min ghrelin and HR AUCs (P = 0.007, r = 0.966) in men. No statistically significant correlations were seen in women. Physiological changes in the levels of glucose, insulin, GLP-1 and ghrelin may influence the activity of the heart and the blood pressure. There may also be gender-related differences in the haemodynamic responses to postprandial changes in hormone levels. The results of this study show that subjects should not eat immediately prior to, or during, the evaluation of cardiovascular interventions as postprandial affects may affect the results, leading to erroneous interpretation of the cardiovascular effects of the primary intervention. NCT01027507.

  4. The Blood Volume of the Guinea Pig: Effects of Epinephrine and Isoproterenol upon the Red Cell and Plasma Volumes, Heart Rate, and Mean Arterial Pressure,

    Science.gov (United States)

    1987-09-01

    capillaries (4), blood volumes calculated from plasma volume measures must correct for label that has left the system between the time of the injected dose...Splenic sequestration and contraction are mediated by the autonomic nervous system and blood-borne agents (10). Sympathetic nerve fibers from the truncus...sympathlcus and parasympathetic neurons of the nervus vagus (cranial nerve X) innervate the celiac plexus (8, 11). A subdivision of the celiac plexus

  5. High Intensity Interval Training Leads to Greater Improvements in Acute Heart Rate Recovery and Anaerobic Power as High Volume Low Intensity Training

    Science.gov (United States)

    Stöggl, Thomas L.; Björklund, Glenn

    2017-01-01

    The purpose of the current study was to explore if training regimes utilizing diverse training intensity distributions result in different responses on neuromuscular status, anaerobic capacity/power and acute heart rate recovery (HRR) in well-trained endurance athletes. Methods: Thirty-six male (n = 33) and female (n = 3) runners, cyclists, triathletes and cross-country skiers [peak oxygen uptake: (VO2peak): 61.9 ± 8.0 mL·kg−1·min−1] were randomly assigned to one of three groups (blocked high intensity interval training HIIT; polarized training POL; high volume low intensity oriented control group CG/HVLIT applying no HIIT). A maximal anaerobic running/cycling test (MART/MACT) was performed prior to and following a 9-week training period. Results: Only the HIIT group achieved improvements in peak power/velocity (+6.4%, P 0.05). Acute HRR was improved in HIIT (11.2%, P = 0.002) and POL (7.9%, P = 0.023) with no change in the HVLIT oriented control group. Conclusion: Only a training regime that includes a significant amount of HIIT improves the neuromuscular status, anaerobic power and the acute HRR in well-trained endurance athletes. A training regime that followed more a low and moderate intensity oriented model (CG/HVLIT) had no effect on any performance or HRR outcomes. PMID:28824457

  6. Energetic Interrelationship between Spontaneous Low-Frequency Fluctuations in Regional Cerebral Blood Volume, Arterial Blood Pressure, Heart Rate, and Respiratory Rhythm

    Science.gov (United States)

    Katura, Takusige; Yagyu, Akihiko; Obata, Akiko; Yamazaki, Kyoko; Maki, Atsushi; Abe, Masanori; Tanaka, Naoki

    2007-07-01

    Strong spontaneous fluctuations around 0.1 and 0.3 Hz have been observed in blood-related brain-function measurements such as functional magnetic resonance imaging and optical topography (or functional near-infrared spectroscopy). These fluctuations seem to reflect the interaction between the cerebral circulation system and the systemic circulation system. We took an energetic viewpoint in our analysis of the interrelationships between fluctuations in cerebral blood volume (CBV), mean arterial blood pressure (MAP), heart rate (HR), and respiratory rhythm based on multivariate autoregressive modeling. This approach involves evaluating the contribution of each fluctuation or rhythm to specific ones by performing multivariate spectral analysis. The results we obtained show MAP and HR can account slightly for the fluctuation around 0.1 Hz in CBV, while the fluctuation around 0.3 Hz is derived mainly from the respiratory rhythm. During our presentation, we will report on the effects of posture on the interrelationship between the fluctuations and the respiratory rhythm.

  7. The effect of endogenously released glucose, insulin, glucagon-like peptide 1, ghrelin on cardiac output, heart rate, stroke volume, and blood pressure

    Directory of Open Access Journals (Sweden)

    Hlebowicz Joanna

    2011-12-01

    Full Text Available Abstract Background Ingestion of a meal increases the blood flow to the gastrointestinal organs and affects the heart rate (HR, blood pressure and cardiac output (CO, although the mechanisms are not known. The aim of this study was to evaluate the effect of endogenously released glucose, insulin, glucagon-like peptide 1 (GLP-1, ghrelin on CO, HR, stroke volume (SV, and blood pressure. Methods Eleven healthy men and twelve healthy women ((mean ± SEM aged: 26 ± 0.2 y; body mass index: 21.8 ± 0.1 kg/m2 were included in this study. The CO, HR, SV, systolic and diastolic blood pressure, antral area, gastric emptying rate, and glucose, insulin, GLP-1 and ghrelin levels were measured. Results The CO and SV at 30 min were significantly higher, and the diastolic blood pressure was significantly lower, than the fasting in both men and women (P P = 0.015, r = 0.946, and between ghrelin levels and HR (P = 0.013, r = 0.951 at 110 min. Significant correlations were also found between the change in glucose level at 30 min and the change in systolic blood pressure (P = 0.021, r = -0.681, and the change in SV (P = 0.008, r = -0.748 relative to the fasting in men. The insulin 0-30 min AUC was significantly correlated to the CO 0-30 min AUC (P = 0.002, r = 0.814 in men. Significant correlations were also found between the 0-120 min ghrelin and HR AUCs (P = 0.007, r = 0.966 in men. No statistically significant correlations were seen in women. Conclusions Physiological changes in the levels of glucose, insulin, GLP-1 and ghrelin may influence the activity of the heart and the blood pressure. There may also be gender-related differences in the haemodynamic responses to postprandial changes in hormone levels. The results of this study show that subjects should not eat immediately prior to, or during, the evaluation of cardiovascular interventions as postprandial affects may affect the results, leading to erroneous interpretation of the cardiovascular effects of the

  8. Heart rate variability in newborns.

    Science.gov (United States)

    Javorka, K; Lehotska, Z; Kozar, M; Uhrikova, Z; Kolarovszki, B; Javorka, M; Zibolen, M

    2017-09-22

    Heart rate (HR) and heart rate variability (HRV) in newborns is influenced by genetic determinants, gestational and postnatal age, and other variables. Premature infants have a reduced HRV. In neonatal HRV evaluated by spectral analysis, a dominant activity can be found in low frequency (LF) band (combined parasympathetic and sympathetic component). During the first postnatal days the activity in the high frequency (HF) band (parasympathetic component) rises, together with an increase in LF band and total HRV. Hypotrophy in newborn can cause less mature autonomic cardiac control with a higher contribution of sympathetic activity to HRV as demonstrated by sequence plot analysis. During quiet sleep (QS) in newborns HF oscillations increase - a phenomenon less expressed or missing in premature infants. In active sleep (AS), HRV is enhanced in contrast to reduced activity in HF band due to the rise of spectral activity in LF band. Comparison of the HR and HRV in newborns born by physiological vaginal delivery, without (VD) and with epidural anesthesia (EDA) and via sectio cesarea (SC) showed no significant differences in HR and in HRV time domain parameters. Analysis in the frequency domain revealed, that the lowest sympathetic activity in chronotropic cardiac chronotropic regulation is in the VD group. Different neonatal pathological states can be associated with a reduction of HRV and an improvement in the health conditions is followed by changes in HRV what can be use as a possible prognostic marker. Examination of heart rate variability in neonatology can provide information on the maturity of the cardiac chronotropic regulation in early postnatal life, on postnatal adaptation and in pathological conditions about the potential dysregulation of cardiac function in newborns, especially in preterm infants.

  9. 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 heart rate. This effect was independent of baseline blood pressure. In conclusion sodium reduction...

  10. High Intensity Interval Training Leads to Greater Improvements in Acute Heart Rate Recovery and Anaerobic Power as High Volume Low Intensity Training

    Directory of Open Access Journals (Sweden)

    Thomas L. Stöggl

    2017-08-01

    Full Text Available The purpose of the current study was to explore if training regimes utilizing diverse training intensity distributions result in different responses on neuromuscular status, anaerobic capacity/power and acute heart rate recovery (HRR in well-trained endurance athletes.Methods: Thirty-six male (n = 33 and female (n = 3 runners, cyclists, triathletes and cross-country skiers [peak oxygen uptake: (VO2peak: 61.9 ± 8.0 mL·kg−1·min−1] were randomly assigned to one of three groups (blocked high intensity interval training HIIT; polarized training POL; high volume low intensity oriented control group CG/HVLIT applying no HIIT. A maximal anaerobic running/cycling test (MART/MACT was performed prior to and following a 9-week training period.Results: Only the HIIT group achieved improvements in peak power/velocity (+6.4%, P < 0.001 and peak lactate (P = 0.001 during the MART/MACT, while, unexpectedly, in none of the groups the performance at the established lactate concentrations (4, 6, 10 mmol·L−1 was changed (P > 0.05. Acute HRR was improved in HIIT (11.2%, P = 0.002 and POL (7.9%, P = 0.023 with no change in the HVLIT oriented control group.Conclusion: Only a training regime that includes a significant amount of HIIT improves the neuromuscular status, anaerobic power and the acute HRR in well-trained endurance athletes. A training regime that followed more a low and moderate intensity oriented model (CG/HVLIT had no effect on any performance or HRR outcomes.

  11. Automatic exposure control at single- and dual-heartbeat CTCA on a 320-MDCT volume scanner: effect of heart rate, exposure phase window setting, and reconstruction algorithm.

    Science.gov (United States)

    Funama, Yoshinori; Utsunomiya, Daisuke; Taguchi, Katsuyuki; Oda, Seitaro; Shimonobo, Toshiaki; Yamashita, Yasuyuki

    2014-05-01

    To investigate whether electrocardiogram (ECG)-gated single- and dual-heartbeat computed tomography coronary angiography (CTCA) with automatic exposure control (AEC) yields images with uniform image noise at reduced radiation doses. Using an anthropomorphic chest CT phantom we performed prospectively ECG-gated single- and dual-heartbeat CTCA on a second-generation 320-multidetector CT volume scanner. The exposure phase window was set at 75%, 70-80%, 40-80%, and 0-100% and the heart rate at 60 or 80 or corr80 bpm; images were reconstructed with filtered back projection (FBP) or iterative reconstruction (IR, adaptive iterative dose reduction 3D). We applied AEC and set the image noise level to 20 or 25 HU. For each technique we determined the image noise and the radiation dose to the phantom center. With half-scan reconstruction at 60 bpm, a 70-80% phase window- and a 20-HU standard deviation (SD) setting, the imagenoise level and -variation along the z axis manifested similar curves with FBP and IR. With half-scan reconstruction, the radiation dose to the phantom center with 70-80% phase window was 18.89 and 12.34 mGy for FBP and 4.61 and 3.10 mGy for IR at an SD setting SD of 20 and 25 HU, respectively. At 80 bpm with two-segment reconstruction the dose was approximately twice that of 60 bpm at both SD settings. However, increasing radiation dose at corr80 bpm was suppressed to 1.39 times compared to 60 bpm. AEC at ECG-gated single- and dual-heartbeat CTCA controls the image noise at different radiation dose. Copyright © 2013 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  12. High Intensity Interval Training Leads to Greater Improvements in Acute Heart Rate Recovery and Anaerobic Power as High Volume Low Intensity Training

    OpenAIRE

    Thomas L. Stöggl; Glenn Björklund; Glenn Björklund

    2017-01-01

    The purpose of the current study was to explore if training regimes utilizing diverse training intensity distributions result in different responses on neuromuscular status, anaerobic capacity/power and acute heart rate recovery (HRR) in well-trained endurance athletes.Methods: Thirty-six male (n = 33) and female (n = 3) runners, cyclists, triathletes and cross-country skiers [peak oxygen uptake: (VO2peak): 61.9 ± 8.0 mL·kg−1·min−1] were randomly assigned to one of three groups (blocked high ...

  13. 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.

  14. 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

  15. Measuring heart rate with optical sensor

    NARCIS (Netherlands)

    Barachi, M. (Mitra)

    2014-01-01

    The problem addressed in this report is to verify the possibility of using an optical sensor in the SaxShirt in order to extract the heart rate. There are specifically three questions that we try to address. 1) How is it possible to extract heart rate (BPM) from the optical sensor? 2) Is it

  16. 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 hypoxi...

  17. Radiographic heart-volume estimation in normal cats

    International Nuclear Information System (INIS)

    Ahlberg, N.E.; Hansson, K.; Svensson, L.; Iwarsson, K.

    1989-01-01

    Heart volume mensuration was evaluated on conventional radiographs from eight normal cats in different body positions using computed tomography (CT). Heart volumes were calculated from orthogonal thoracic radiographs in ventral and dorsal recumbency and from radiographs exposed with a vertical X-ray beam in dorsal and lateral recumbency using the formula for an ellipsoid body. Heart volumes were also estimated with CT in ventral, dorsal, right lateral and left lateral recumbency. No differences between heart volumes from CT in ventral recumbency and those from CT in right and left lateral recumbency were seen. In dorsal recumbency, however, significantly lower heart volumes were obtained. Heart volumes from CT in ventral recumbency were similar to those from radiographs in ventral and dorsal recumbency and dorsal/left lateral recumbency. Close correlation was also demonstrated between heart volumes from radiographs in dorsal/ left lateral recumbency and body weights of the eight cats

  18. Heart rate variability in healthy population

    International Nuclear Information System (INIS)

    Alamgir, M.; Hussain, M.M.

    2010-01-01

    Background: Heart rate variability has been considered as an indicator of autonomic status. Little work has been done on heart rate variability in normal healthy volunteers. We aimed at evolving the reference values of heart rate variability in our healthy population. Methods: Twenty-four hour holter monitoring of 37 healthy individuals was done using Holter ECG recorder 'Life card CF' from 'Reynolds Medical'. Heart rate variability in both time and frequency domains was analysed with 'Reynolds Medical Pathfinder Digital/700'. Results: The heart rate variability in normal healthy volunteers of our population was found in time domain using standard deviation of R-R intervals (SDNN), standard deviation of average NN intervals (SDANN), and Square root of the mean squared differences of successive NN intervals (RMSSD). Variation in heart rate variability indices was observed between local and foreign volunteers and RMSSD was found significantly increased (p<0.05) in local population. Conclusions: The values of heart rate variability (RMSSD) in healthy Pakistani volunteers were found increased compared to the foreign data reflecting parasympathetic dominance in our population. (author)

  19. Metaiodobenzylguanidine and heart rate variability in heart failure

    International Nuclear Information System (INIS)

    Kurata, Chinori; Shouda, Sakae; Mikami, Tadashi; Uehara, Akihiko; Ishikawa, Keiko; Tawarahara, Kei; Nakano, Tomoyasu; Matoh, Fumitaka; Takeuchi, Kazuhiko

    1998-01-01

    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 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)

  20. 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)

  1. 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.

  2. The clinical importance of radiological determination of the heart volume

    International Nuclear Information System (INIS)

    Jaedicke, W.; Ong, T.S.; Barmeyer, J.

    1982-01-01

    The size of the heart is an autonomous, important parameter of its functional state, i.e. in the radiologic heart diagnostics, the measurement of the heart volume is of equal value as the shape analysis. A size determination which must be exact enough for course controls and differentiation from the normal picture makes sense only if the measurement is carriet out in 3 dimensions and not in only one as is done when determining the heart-lung-quotient. The heart volume measurement carried out in lying or sitting position is considerably more reliable than in standing position as too many extracardiac factors influence the heart volume when the patient is standing. The echo cardiogram is a nearly ideal supplement but no competitor of radiological heart volume measurement and can be of the same value as or superior to heart volume measurement for functional diagnostics only in diseases limited to nearly exclusively to the left ventricle as in coronary diseases. (orig.) [de

  3. Fetal Heart Rate Monitoring during Labor

    Science.gov (United States)

    ... What are the types of monitoring? • How is auscultation performed? • How is electronic fetal monitoring performed? • How ... methods of fetal heart rate monitoring in labor. Auscultation is a method of periodically listening to the ...

  4. The relationship between phase and heart rate

    International Nuclear Information System (INIS)

    Underwood, S.R.; Walton, S.; Brown, N.J.G.; Laming, P.J.; Ell, P.J.; Emanuel, R.W.; Swanton, R.H.

    1984-01-01

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

  5. Heart Rate Variability - A Historical Perspective

    Directory of Open Access Journals (Sweden)

    George E Billman

    2011-11-01

    Full Text Available Heart rate variability (HRV, the beat-to-beat variation in either heart rate or the duration of the R-R interval – the heart period, has become a popular clinical and investigational tool. The temporal fluctuations in heart rate exhibit a marked synchrony with respiration (increasing during inspiration and decreasing during expiration – the so called respiratory sinus arrhythmia, RSA and are widely believed to reflect changes in cardiac autonomic regulation. Although the exact contributions of the parasympathetic and the sympathetic divisions of the autonomic nervous system to this variability are controversial and remain the subject of active investigation and debate, a number of time and frequency domain techniques have been developed to provide insight into cardiac autonomic regulation in both health and disease. It is the purpose of this essay to provide an historical overview of the evolution in the concept of heart rate variability. Briefly, pulse rate was first measured by ancient Greek physicians and scientists. However, it was not until the invention of the Physician’s Pulse Watch (a watch with a second hand that could be stopped in 1707 that changes in pulse rate could be accurately assessed. The Rev. Stephen Hales (1733 was the first to note that pulse varied with respiration and in 1847 Carl Ludwig was the first to record RSA. With the measurement of the ECG (1895 and advent of digital signal processing techniques in the 1960’s, investigation of HRV and its relationship to health and disease has exploded. This essay will conclude with a brief description of time domain, frequency domain, and non-linear dynamic analysis techniques (and their limitations that are commonly used to measure heart rate variability.

  6. 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.

  7. Heart rate response to hypoxic exercise

    DEFF Research Database (Denmark)

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

    2001-01-01

    progressively decreased the maximal heart rate from day 1 and onwards; also, hypoxia by itself increased plasma noradrenaline levels after maximal exercise. Domperidone further increased maximal noradrenaline concentrations, but had no effect on maximal heart rate. On each study day at altitude, oxygen......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...

  8. Monitoring apparatus for monitoring a user's heart rate and/or heart rate variation

    NARCIS (Netherlands)

    2012-01-01

    A monitoring apparatus (4) monitors a user's heart rate and/or heart rate variation. The apparatus includes a capacitor (22) which is positionable on or near a body part of a person, for example a person's limb, for example an arm (3), such that an electrical capacitance of the capacitor (22) is

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

    NARCIS (Netherlands)

    Jong, de I.C.; Sgoifo, A.; Lambooij, E.; Korte, S.M.; Blokhuis, H.J.; Koolhaas, J.M.

    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

  10. 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

  11. Heart rate variability in bipolar disorder

    DEFF Research Database (Denmark)

    Faurholt-Jepsen, Maria; Kessing, Lars Vedel; Munkholm, Klaus

    2017-01-01

    Background Heart rate variability (HRV) has been suggested reduced in bipolar disorder (BD) compared with healthy individuals (HC). This meta-analysis investigated: HRV differences in BD compared with HC, major depressive disorder or schizophrenia; HRV differences between affective states; HRV...

  12. Arrhenius Rate: constant volume burn

    Energy Technology Data Exchange (ETDEWEB)

    Menikoff, Ralph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-12-06

    A constant volume burn occurs for an idealized initial state in which a large volume of reactants at rest is suddenly raised to a high temperature and begins to burn. Due to the uniform spatial state, there is no fluid motion and no heat conduction. This reduces the time evolu tion to an ODE for the reaction progress variable. With an Arrhenius reaction rate, two characteristics of thermal ignition are illustrated: induction time and thermal runaway. The Frank-Kamenetskii approximation then leads to a simple expression for the adiabatic induction time. For a first order reaction, the analytic solution is derived and used to illustrate the effect of varying the activation temperature; in particular, on the induction time. In general, the ODE can be solved numerically. This is used to illustrate the effect of varying the reaction order. We note that for a first order reaction, the time evolution of the reaction progress variable has an exponential tail. In contrast, for a reaction order less than one, the reaction completes in a nite time. The reaction order also affects the induction time.

  13. Heart Rate Fragmentation: A Symbolic Dynamical Approach

    Directory of Open Access Journals (Sweden)

    Madalena D. Costa

    2017-11-01

    Full Text Available Background: We recently introduced the concept of heart rate fragmentation along with a set of metrics for its quantification. The term was coined to refer to an increase in the percentage of changes in heart rate acceleration sign, a dynamical marker of a type of anomalous variability. The effort was motivated by the observation that fragmentation, which is consistent with the breakdown of the neuroautonomic-electrophysiologic control system of the sino-atrial node, could confound traditional short-term analysis of heart rate variability.Objective: The objectives of this study were to: (1 introduce a symbolic dynamical approach to the problem of quantifying heart rate fragmentation; (2 evaluate how the distribution of the different dynamical patterns (“words” varied with the participants' age in a group of healthy subjects and patients with coronary artery disease (CAD; and (3 quantify the differences in the fragmentation patterns between the two sample populations.Methods: The symbolic dynamical method employed here was based on a ternary map of the increment NN interval time series and on the analysis of the relative frequency of symbolic sequences (words with a pre-defined set of features. We analyzed annotated, open-access Holter databases of healthy subjects and patients with CAD, provided by the University of Rochester Telemetric and Holter ECG Warehouse (THEW.Results: The degree of fragmentation was significantly higher in older individuals than in their younger counterparts. However, the fragmentation patterns were different in the two sample populations. In healthy subjects, older age was significantly associated with a higher percentage of transitions from acceleration/deceleration to zero acceleration and vice versa (termed “soft” inflection points. In patients with CAD, older age was also significantly associated with higher percentages of frank reversals in heart rate acceleration (transitions from acceleration to

  14. Gaussian Mixture Model of Heart Rate Variability

    Science.gov (United States)

    Costa, Tommaso; Boccignone, Giuseppe; Ferraro, Mario

    2012-01-01

    Heart rate variability (HRV) is an important measure of sympathetic and parasympathetic functions of the autonomic nervous system and a key indicator of cardiovascular condition. This paper proposes a novel method to investigate HRV, namely by modelling it as a linear combination of Gaussians. Results show that three Gaussians are enough to describe the stationary statistics of heart variability and to provide a straightforward interpretation of the HRV power spectrum. Comparisons have been made also with synthetic data generated from different physiologically based models showing the plausibility of the Gaussian mixture parameters. PMID:22666386

  15. Heart Performance Determination by Visualization in Larval Fishes: Influence of Alternative Models for Heart Shape and Volume

    Directory of Open Access Journals (Sweden)

    Prescilla Perrichon

    2017-07-01

    Full Text Available Understanding cardiac function in developing larval fishes is crucial for assessing their physiological condition and overall health. Cardiac output measurements in transparent fish larvae and other vertebrates have long been made by analyzing videos of the beating heart, and modeling this structure using a conventional simple prolate spheroid shape model. However, the larval fish heart changes shape during early development and subsequent maturation, but no consideration has been made of the effect of different heart geometries on cardiac output estimation. The present study assessed the validity of three different heart models (the “standard” prolate spheroid model as well as a cylinder and cone tip + cylinder model applied to digital images of complete cardiac cycles in larval mahi-mahi and red drum. The inherent error of each model was determined to allow for more precise calculation of stroke volume and cardiac output. The conventional prolate spheroid and cone tip + cylinder models yielded significantly different stroke volume values at 56 hpf in red drum and from 56 to 104 hpf in mahi. End-diastolic and stroke volumes modeled by just a simple cylinder shape were 30–50% higher compared to the conventional prolate spheroid. However, when these values of stroke volume multiplied by heart rate to calculate cardiac output, no significant differences between models emerged because of considerable variability in heart rate. Essentially, the conventional prolate spheroid shape model provides the simplest measurement with lowest variability of stroke volume and cardiac output. However, assessment of heart function—especially if stroke volume is the focus of the study—should consider larval heart shape, with different models being applied on a species-by-species and developmental stage-by-stage basis for best estimation of cardiac output.

  16. Normal radiographic heart volume in the neonate. Pt. 3

    International Nuclear Information System (INIS)

    Dahlstroem, A.; Ringertz, H.G.; Sachsska Pediatric Hospital, Stockholm

    1985-01-01

    The diagnostic power of the heart volume and the cardiothoracic ratio in congenital heart disease in neonates has been compared. A consecutive series of 130 children with suspection of heart disease examined radiologically at between 48 h and 15 days of age were followed for 14+-10 months. Of these, 16 (12%) were diagnosed as having congenital heart disease. The number of false positive and negative diagnoses was less for heart volume than for cardiothoracic ratio using +2 SD as limit for pathology. Accuracy, sensitivity and specificity was 84, 75, and 85% respectively for heart volume and 73, 57, and 75% for cardiothoracic ratio. Cases that were false positive with both methods were significantly more often examined between 48 and 72 hours of age indicating that the explanation might be a somewhat late closure of the ductus arteriosus. (orig.)

  17. Radiocardiographic determination of the stroke volume and of the heart minute volume in athletes

    Energy Technology Data Exchange (ETDEWEB)

    Sattler, R; Stoll, W [Friedrich-Schiller-Universitaet, Jena (German Democratic Republic). Radiologische Klinik

    1981-11-01

    Radiocardiography, a novel radioisotope method for the problemless determination of many cardiodynamic parameters which can be applied also at given physical exercise is presented. On the basis of stroke volume and heart minute volume values from 35 athletes practising different sports and of a comparison with normal values reported in the literature, differences in the cardiac adaptation and the function of athletic hearts and so-called normal hearts are pointed out. The stroke volume of endurance-trained athletes exceeds that of untrained individuals by 30-40 ml. Under exercise the increase of the stroke volume is considerably greater in endurance athletes than in individuals practising other sports or in untrained subjects. At rest the values of the heart minute volume are almost the same in athletes and untrained individuals. Under exercise the heart minute volume of endurance athletes (40 l/min) is nearly twice that of untrained individuals (volume reserve of the athlete).

  18. Radiocardiographic determination of the stroke volume and of the heart minute volume in athletes

    International Nuclear Information System (INIS)

    Sattler, R.; Stoll, W.

    1981-01-01

    Radiocardiography, a novel radioisotope method for the problemless determination of many cardiodynamic parameters which can be applied also at given physical exercise is presented. On the basis of stroke volume and heart minute volume values from 35 athletes practising different sports and of a comparison with normal values reported in the literature, differences in the cardiac adaptation and the function of athletic hearts and so-called normal hearts are pointed out. The stroke volume of endurance-trained athetes exceed that of untrained individuals by 30-40 ml. Under exercise the increase of the stroke volume is considerably greater in endurance athletes than in individuals practising other sports or in untrained subjects. At rest the values of the heart minute volume are almost the same in athletes and untrained individuals. Under exercise the heart minute volume of endurance athletes (40 l/min) is nearly twice that of untrained individuals (volume reserve of the athlete). (author)

  19. Heart rate variability - a historical perspective.

    Science.gov (United States)

    Billman, George E

    2011-01-01

    Heart rate variability (HRV), the beat-to-beat variation in either heart rate or the duration of the R-R interval - the heart period, has become a popular clinical and investigational tool. The temporal fluctuations in heart rate exhibit a marked synchrony with respiration (increasing during inspiration and decreasing during expiration - the so called respiratory sinus arrhythmia, RSA) and are widely believed to reflect changes in cardiac autonomic regulation. Although the exact contributions of the parasympathetic and the sympathetic divisions of the autonomic nervous system to this variability are controversial and remain the subject of active investigation and debate, a number of time and frequency domain techniques have been developed to provide insight into cardiac autonomic regulation in both health and disease. It is the purpose of this essay to provide an historical overview of the evolution in the concept of HRV. Briefly, pulse rate was first measured by ancient Greek physicians and scientists. However, it was not until the invention of the "Physician's Pulse Watch" (a watch with a second hand that could be stopped) in 1707 that changes in pulse rate could be accurately assessed. The Rev. Stephen Hales (1733) was the first to note that pulse varied with respiration and in 1847 Carl Ludwig was the first to record RSA. With the measurement of the ECG (1895) and advent of digital signal processing techniques in the 1960s, investigation of HRV and its relationship to health and disease has exploded. This essay will conclude with a brief description of time domain, frequency domain, and non-linear dynamic analysis techniques (and their limitations) that are commonly used to measure HRV.

  20. Early warnings of heart rate deterioration

    OpenAIRE

    Almeida, Vânia G.; Nabney, Ian T.

    2016-01-01

    Hospitals can experience difficulty in detecting and responding to early signs of patient deterioration leading to late intensive care referrals, excess mortality and morbidity, and increased hospital costs. Our study aims to explore potential indicators of physiological deterioration by the analysis of vital-signs. The dataset used comprises heart rate (HR) measurements from MIMIC II waveform database, taken from six patients admitted to the Intensive Care Unit (ICU) and diagnosed with sever...

  1. 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

  2. High readmission rate after heart valve surgery

    DEFF Research Database (Denmark)

    Sibilitz, K L; Berg, S K; Thygesen, L C

    2015-01-01

    investigated. RESULTS: After valve surgery, the self-reported health was lower (Short Form-36 (SF-36) Physical Component Scale (PCS): 44.5 vs. 50.6 and Mental Component Scale (MCS): 51.9 vs. 55.0, pClinical signs......BACKGROUND: After heart valve surgery, knowledge on long-term self-reported health status and readmission is lacking. Thus, the optimal strategy for out-patient management after surgery remains unclear. METHODS: Using a nationwide survey with linkage to Danish registers with one year follow-up, we...... included all adults 6-12months after heart valve surgery irrespective of valve procedure, during Jan-June 2011 (n=867). Participants completed a questionnaire regarding health-status (n=742), and answers were compared with age- and sex-matched healthy controls. Readmission rates and mortality were...

  3. 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 decrement (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 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.

  4. 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.

  5. Simultaneous measurement of instantaneous heart rate and chest wall plethysmography in short-term, metronome guided heart rate variability studies: suitability for assessment of autonomic dysfunction.

    Science.gov (United States)

    Perring, S; Jones, E

    2003-08-01

    Instantaneous heart rate and chest wall motion were measured using a 3-lead ECG and an air pressure chest wall plethysmography system. Chest wall plethysmography traces were found to accurately represent the breathing pattern as measured by spirometry (average correlation coefficient 0.944); though no attempt was made to calibrate plethysmography voltage output to tidal volume. Simultaneous measurements of heart rate and chest wall motion were made for short periods under metronome guided breathing at 6 breaths per minute. The average peak to trough heart rate change per breath cycle (AVEMAX) and maximum correlation between heart rate and breathing cycle (HRBRCORR) were measured. Studies of 44 normal volunteers indicated clear inverse correlation of heart rate variability parameters with age (AVEMAX R = -0.502, P < 0.001) but no significant change in HRBRCORR with age (R = -0.115). Comparison of normal volunteers with diabetics with no history of symptoms associated with autonomic failure indicated significant lower heart rate variability in diabetics (P = 0.005 for AVEMAX) and significantly worse correlation between heart rate and breathing (P < 0.001 for HRBRCORR). Simultaneous measurement of heart rate and breathing offers the possibility of more sensitive diagnosis of autonomic failure in a simple bedside test and gives further insight into the nature of cardio-ventilatory coupling.

  6. Radionuclide determined pulmonary blood volume in ischaemic heart disease

    International Nuclear Information System (INIS)

    Hannan, W.J.; Vojacek, J.; Connell, H.M. Dewhurst N.G.; Muir, A.L.

    1981-01-01

    Most measurements of pulmonary blood volume have been based on the Stewart-Hamilton dye dilution principle and have required direct catheterisation of the cardiac chambers. Alternatively a precordial counter may be used to detect the composite right and left heart curves after an intravenous injection of radionuclide. We investigated the use of a gamma camera/computer system to determine the radionuclide (sup(99m)Tc) dilution curves from individual cardiac chambers. Pulmonary transit time and pulmonary blood volume were measured in nine normal subjects, eight patients with angina pectoris but without heart failure, and 13 patients with ischaemic heart disease and left ventricular failure. Patients with heart failure had significantly greater (p 0 angle. A reduction in pulmonary blood volume in the tilted position was observed in each subject (p < 0.005). This simple non-invasive measurement should allow more detailed assessment of physiological or pharmacological changes of the pulmonary vascular bed. (author)

  7. 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.

  8. Heart-Rate Variability-More than Heart Beats?

    Science.gov (United States)

    Ernst, Gernot

    2017-01-01

    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.

  9. 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.

  10. Heart and soul: heart rate variability and major depression.

    Science.gov (United States)

    Kidwell, Meyrick; Ellenbroek, Bart A

    2018-04-01

    There is a bidirectional relationship between affective disorders and cardiovascular abnormalities, often described as a downward spiral, whereas major depressive disorders (MDD, and anxiety disorders) significantly increase the risk of developing cardiovascular diseases (CVD); CVD are also associated with increased risk of developing MDD (and anxiety disorders). Moreover, the prognosis and progression of CVD is significantly worsened in the presence of MDD. Heart rate variability (HRV) has often been suggested as a potential mediator in this comorbidity. In this review, we discuss HRV alterations in MDD. However, we mainly focus on the direct relationship between HRV alterations and psychiatric symptoms, rather than its relationship with CVD, as this has been reviewed elsewhere. After a general introduction to HRV and how it can be measured, we review how HRV is altered in MDD. We subsequently describe how antidepressant drugs affect HRV, showing that some classes (such as tricyclics) generally worsen HRV, whereas others (most notably selective serotonin reuptake inhibitors) have a more positive influence. We also review the effects of several other treatments, with a special focus on vagal nerve stimulation, finishing with some further considerations and recommendation for further research, both in humans and animals.

  11. Validation of Heart Rate Monitor Polar RS800 for Heart Rate Variability Analysis During Exercise.

    Science.gov (United States)

    Hernando, David; Garatachea, Nuria; Almeida, Rute; Casajús, Jose A; Bailón, Raquel

    2018-03-01

    Hernando, D, Garatachea, N, Almeida, R, Casajús, JA, and Bailón, R. Validation of heart rate monitor Polar RS800 for heart rate variability analysis during exercise. J Strength Cond Res 32(3): 716-725, 2018-Heart rate variability (HRV) analysis during exercise is an interesting noninvasive tool to measure the cardiovascular response to the stress of exercise. Wearable heart rate monitors are a comfortable option to measure interbeat (RR) intervals while doing physical activities. It is necessary to evaluate the agreement between HRV parameters derived from the RR series recorded by wearable devices and those derived from an electrocardiogram (ECG) during dynamic exercise of low to high intensity. Twenty-three male volunteers performed an exercise stress test on a cycle ergometer. Subjects wore a Polar RS800 device, whereas ECG was also recorded simultaneously to extract the reference RR intervals. A time-frequency spectral analysis was performed to extract the instantaneous mean heart rate (HRM), and the power of low-frequency (PLF) and high-frequency (PHF) components, the latter centered on the respiratory frequency. Analysis was done in intervals of different exercise intensity based on oxygen consumption. Linear correlation, reliability, and agreement were computed in each interval. The agreement between the RR series obtained from the Polar device and from the ECG is high throughout the whole test although the shorter the RR is, the more differences there are. Both methods are interchangeable when analyzing HRV at rest. At high exercise intensity, HRM and PLF still presented a high correlation (ρ > 0.8) and excellent reliability and agreement indices (above 0.9). However, the PHF measurements from the Polar showed reliability and agreement coefficients around 0.5 or lower when the level of the exercise increases (for levels of O2 above 60%).

  12. Increased heart rate variability during nondirective meditation.

    Science.gov (United States)

    Nesvold, Anders; Fagerland, Morten W; Davanger, Svend; Ellingsen, Øyvind; Solberg, Erik E; Holen, Are; Sevre, Knut; Atar, Dan

    2012-08-01

    Meditation practices are in use for relaxation and stress reduction. Some studies indicate beneficial cardiovascular health effects of meditation. The effects on the autonomous nervous system seem to vary among techniques. The purpose of the present study was to identify autonomic nerve activity changes during nondirective meditation. Heart rate variability (HRV), blood pressure variability (BPV), and baroreflex sensitivity (BRS) were monitored in 27 middle-aged healthy participants of both genders, first during 20 min regular rest with eyes closed, thereafter practising Acem meditation for 20 min. Haemodynamic and autonomic data were collected continuously (beat-to-beat) and non-invasively. HRV and BPV parameters were estimated by power spectral analyses, computed by an autoregressive model. Spontaneous activity of baroreceptors were determined by the sequence method. Primary outcomes were changes in HRV, BPV, and BRS between rest and meditation. HRV increased in the low-frequency (LF) and high-frequency (HF) bands during meditation, compared with rest (p = 0.014, 0.013, respectively). Power spectral density of the RR-intervals increased as well (p = 0.012). LF/HF ratio decreased non-significantly, and a reduction of LF-BPV power was observed during meditation (p < 0.001). There was no significant difference in BRS. Respiration and heart rates remained unchanged. Blood pressure increased slightly during meditation. There is an increased parasympathetic and reduced sympathetic nerve activity and increased overall HRV, while practising the technique. Hence, nondirective meditation by the middle aged may contribute towards a reduction of cardiovascular risk.

  13. iPhone 4s photoplethysmography: which light color yields the most accurate heart rate and normalized pulse volume using the iPhysioMeter Application in the presence of motion artifact?

    Directory of Open Access Journals (Sweden)

    Kenta Matsumura

    Full Text Available Recent progress in information and communication technologies has made it possible to measure heart rate (HR and normalized pulse volume (NPV, which are important physiological indices, using only a smartphone. This has been achieved with reflection mode photoplethysmography (PPG, by using a smartphone's embedded flash as a light source and the camera as a light sensor. Despite its widespread use, the method of PPG is susceptible to motion artifacts as physical displacements influence photon propagation phenomena and, thereby, the effective optical path length. Further, it is known that the wavelength of light used for PPG influences the photon penetration depth and we therefore hypothesized that influences of motion artifact could be wavelength-dependant. To test this hypothesis, we made measurements in 12 healthy volunteers of HR and NPV derived from reflection mode plethysmograms recorded simultaneously at three different spectral regions (red, green and blue at the same physical location with a smartphone. We then assessed the accuracy of the HR and NPV measurements under the influence of motion artifacts. The analyses revealed that the accuracy of HR was acceptably high with all three wavelengths (all rs > 0.996, fixed biases: -0.12 to 0.10 beats per minute, proportional biases: r =  -0.29 to 0.03, but that of NPV was the best with green light (r = 0.791, fixed biases: -0.01 arbitrary units, proportional bias: r = 0.11. Moreover, the signal-to-noise ratio obtained with green and blue light PPG was higher than that of red light PPG. These findings suggest that green is the most suitable color for measuring HR and NPV from the reflection mode photoplethysmogram under motion artifact conditions. We conclude that the use of green light PPG could be of particular benefit in ambulatory monitoring where motion artifacts are a significant issue.

  14. Clinical associations of total kidney volume: the Framingham Heart Study.

    Science.gov (United States)

    Roseman, Daniel A; Hwang, Shih-Jen; Oyama-Manabe, Noriko; Chuang, Michael L; O'Donnell, Christopher J; Manning, Warren J; Fox, Caroline S

    2017-08-01

    Total kidney volume (TKV) is an imaging biomarker that may have diagnostic and prognostic utility. The relationships between kidney volume, renal function and cardiovascular disease (CVD) have not been characterized in a large community-dwelling population. This information is needed to advance the clinical application of TKV. We measured TKV in 1852 Framingham Heart Study participants (mean age 64.1 ± 9.2 years, 53% women) using magnetic resonance imaging. A healthy sample was used to define reference values. The associations between TKV, renal function and CVD risk factors were determined using multivariable logistic regression analysis. Overall, mean TKV was 278 ± 54 cm3 for women and 365 ± 66 cm3 for men. Risk factors for high TKV (>90% healthy referent size) were body surface area (BSA), diabetes, smoking and albuminuria, while age, female and estimated glomerular filtration rate (eGFR) kidney damage including albuminuria and eGFR <60 mL/min/1.73 m2, while high TKV is associated with diabetes and decreased odds of eGFR <60 mL/min/1.73 m2. Prospective studies are needed to characterize the natural progression and clinical consequences of TKV. Published by Oxford University Press on behalf of ERA-EDTA 2016. This work is written by US Government employees and is in the public domain in the US.

  15. 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......, 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...... (-1.150 +/- 4.007 vs -2.454 +/- 2.796, P = 0.025, respectively), but values of TS were not statistically different between two groups (10.352 +/- 7.670 vs 9.613 +/- 7.245, P = 0.555, respectively). Also, the number of patients who had abnormal TO was significantly higher in heavy cigarette smokers...

  16. The Effect of 8 Weeks Yoga Training on Respiratory Function and Heart Rate of Non-Athlete Females

    Directory of Open Access Journals (Sweden)

    KH

    2015-07-01

    Conclusions: Results of this study showed that 8 weeks of practicing yoga and pranayama to increase vital capacity and forced expiratory volume in the first second and decreased heart rate and respiratory rate at rest is. Keywords: Yoga, Pranayama, spirometric indices, heart rate

  17. 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...

  18. Heart rate variability interventions for concussion and rehabilitation

    OpenAIRE

    Conder, Robert L.; Conder, Alanna A.

    2014-01-01

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

  19. Cardiovascular Reactivity and Heart Rate Variability in Panic Disorder

    National Research Council Canada - National Science Library

    Santiago, Helen T

    1999-01-01

    .... Because previous studies of cardiovascular reactivity and heart rate variability have been inconclusive, these factors were re-examined in panickers and controls during physiological challenge...

  20. 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.

  1. 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.

  2. Early warnings of heart rate deterioration.

    Science.gov (United States)

    Almeida, Vania G; Nabney, Ian T

    2016-08-01

    Hospitals can experience difficulty in detecting and responding to early signs of patient deterioration leading to late intensive care referrals, excess mortality and morbidity, and increased hospital costs. Our study aims to explore potential indicators of physiological deterioration by the analysis of vital-signs. The dataset used comprises heart rate (HR) measurements from MIMIC II waveform database, taken from six patients admitted to the Intensive Care Unit (ICU) and diagnosed with severe sepsis. Different indicators were considered: 1) generic early warning indicators used in ecosystems analysis (autocorrelation at-1-lag (ACF1), standard deviation (SD), skewness, kurtosis and heteroskedasticity) and 2) entropy analysis (kernel entropy and multi scale entropy). Our preliminary findings suggest that when a critical transition is approaching, the equilibrium state changes what is visible in the ACF1 and SD values, but also by the analysis of the entropy. Entropy allows to characterize the complexity of the time series during the hospital stay and can be used as an indicator of regime shifts in a patient's condition. One of the main problems is its dependency of the scale used. Our results demonstrate that different entropy scales should be used depending of the level of entropy verified.

  3. Study Heart Rate by Tools from Complex Networks

    International Nuclear Information System (INIS)

    Makowiec, D.; Wdowczyk-Szulc, J.; Zarczynska-Buchowiecka, M.; Gruchala, M.; Rynkiewicz, A.

    2011-01-01

    Heart rate measured as beat-to-beat time intervals varies in time. It is believed that time intervals between subsequent normal heart contractions carry information about the regulatory system of the heart. How to quantify such signals is not clear and because of that heart rate variability is still apart from the clinic routine. In the following, we propose a method for representing a heart rate signal as a directed network. Then we study the signal properties by complex network tools. The signals to study were collected from patients recovering after the heart transplantation. The aim is to classify the progress of adapting of the new heart - graft. Moreover, it is expected that the method allows for visual classification. Our investigations are preliminary, however the obtained results are promising. (authors)

  4. [Heart rate variability and physical exercise. Current status].

    Science.gov (United States)

    Hottenrott, Kuno; Hoos, Olaf; Esperer, Hans Dieter

    2006-09-01

    Heart rate variability (HRV) has long been used in risk stratification for sudden cardiac death and diabetic autonomic neuropathy. In recent years, both time and frequency domain indices of HRV also gained increasing interest in sports and training sciences. In these fields, HRV is currently used for the noninvasive assessment of autonomic changes associated with short-term and long-term endurance exercise training in both leisure sports activity and high-performance training. Furthermore, HRV is being investigated as a diagnostic marker of overreaching and overtraining.A large body of evidence shows that, in healthy subjects and cardiovascular patients of all ages (up to an age of 70 years), regular aerobic training usually results in a significant improvement of overall as well as instantaneous HRV. These changes, which are accompanied by significant reductions in heart rates both at rest and during submaximal exercise, reflect an increase in autonomic efferent activity and a shift in favor of enhanced vagal modulation of the cardiac rhythm. Regular aerobic training of moderate volume and intensity over a minimum period of 3 months seems to be necessary to ensure these effects, which might be associated with a prognostic benefit regarding overall mortality.At present, available data does not allow for final conclusions with respect to the usefulness of traditional HRV indices in assessing an individual's exercise performance and monitoring training load. The discrepant results published so far are due to several factors including insufficient study size and design, and different HRV methods. Large-sized and prospectively designed studies are necessary for clarification. It also remains to be seen, whether the traditional HRV indices prove useful in the diagnosis of overreaching and overtraining. Preliminary results, though promising, need to be confirmed in larger cohorts.A basic problem in HRV analysis is nonstationarity of the heart rate signal, which holds

  5. Reduction of heart volume during neoadjuvant chemoradiation in patients with resectable esophageal cancer

    International Nuclear Information System (INIS)

    Haj Mohammad, Nadia; Kamphuis, Martijn; Hulshof, Maarten C.C.M.; Lutkenhaus, Lotte J.; Gisbertz, Suzanne S.; Bergman, Jacques J.G.H.M.; Bruin-Bon, H.A.C.M. Rianne de; Geijsen, Elisabeth D.; Bel, Arjan; Boekholdt, S. Mathijs; Laarhoven, Hanneke W.M. van

    2015-01-01

    Background and purpose: Neoadjuvant chemoradiation (nCRT) followed by surgery is considered curative intent treatment for patients with resectable esophageal cancer. The aim was to establish hemodynamic aspects of changes in heart volume and to explore whether changes in heart volume resulted in clinically relevant changes in the dose distribution of radiotherapy. Methods: A prospective study was conducted in patients who were treated with nCRT consisting of carboplatin and paclitaxel concomitant with radiotherapy (41.4 Gy/1.8 Gy per fraction). Physical parameters, cardiac volume on CT and Cone beam CT, cardiac blood markers and cardiac ultrasound were obtained. Results: In 23 patients a significant decrease of 55.3 ml in heart volume was detected (95% CI 36.7–73.8 ml, p < 0.001). There was a decrease in both systolic (mean decrease 18 mmHg, 95% CI 11–26 mmHg, p < 0.001) and diastolic blood pressure (mean decrease 8 mmHg, 95% CI 2–14 mmHg, p = 0.008) and an increase in heart rate with 6 beats/min (95% CI 1–11 beats/min, p = 0.021). Except for Troponin T, no change in other cardiac markers and echocardiography parameters were observed. The change in heart volume did not result in a clinically relevant change in radiation dose distribution. Conclusion: Heart volume was significantly reduced, but was not accompanied by overt cardiac dysfunction. All observed changes in hemodynamic parameters are consistent with volume depletion. Adaptation of the treatment plan during the course of radiotherapy is not advocated

  6. 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.

  7. Flow rate measurement in a volume

    Energy Technology Data Exchange (ETDEWEB)

    Galvez, Cristhian

    2018-04-17

    A system for measuring flow rate within a volume includes one or more transmission devices that transmit one or more signals through fluid contained within the volume. The volume may be bounded, at least in part, by an outer structure and by an object at least partially contained within the outer structure. A transmission device located at a first location of the outer structure transmits a first signal to a second location of the outer structure. A second signal is transmitted through the fluid from the second location to a third location of the outer structure. The flow rate of the fluid within the volume may be determined based, at least in part, on the time of flight of both the first signal and the second signal.

  8. White Matter Volume Predicts Language Development in Congenital Heart Disease.

    Science.gov (United States)

    Rollins, Caitlin K; Asaro, Lisa A; Akhondi-Asl, Alireza; Kussman, Barry D; Rivkin, Michael J; Bellinger, David C; Warfield, Simon K; Wypij, David; Newburger, Jane W; Soul, Janet S

    2017-02-01

    To determine whether brain volume is reduced at 1 year of age and whether these volumes are associated with neurodevelopment in biventricular congenital heart disease (CHD) repaired in infancy. Infants with biventricular CHD (n = 48) underwent brain magnetic resonance imaging (MRI) and neurodevelopmental testing with the Bayley Scales of Infant Development-II and the MacArthur-Bates Communicative Development Inventories at 1 year of age. A multitemplate based probabilistic segmentation algorithm was applied to volumetric MRI data. We compared volumes with those of 13 healthy control infants of comparable ages. In the group with CHD, we measured Spearman correlations between neurodevelopmental outcomes and the residuals from linear regression of the volumes on corrected chronological age at MRI and sex. Compared with controls, infants with CHD had reductions of 54 mL in total brain (P = .009), 40 mL in cerebral white matter (P Development-II scores but did correlate positively with MacArthur-Bates Communicative Development Inventory language development. Infants with biventricular CHD show total brain volume reductions at 1 year of age, driven by differences in cerebral white matter. White matter volume correlates with language development, but not broader developmental indices. These findings suggest that abnormalities in white matter development detected months after corrective heart surgery may contribute to language impairment. ClinicalTrials.gov: NCT00006183. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Do high fetal catecholamine levels affect heart rate variability and ...

    African Journals Online (AJOL)

    Objectives. To deternrine the relationship between Umbilical arterial catecholamine levels and fetal heart rate variability and meconium passage. Study design. A prospective descriptive study was perfonned. Umbilical artery catecholamine levels were measured in 55 newborns and correlated with fetal heart rate before ...

  10. Effects of Malaria on Blood Pressure, Heart Rate, Electrocardiogram ...

    African Journals Online (AJOL)

    The effect of malaria on blood pressure, heart rate, electrocardiogram and the cardiovascular responses to postural change were studied in malaria patients. Blood pressure was measured by the sphygmomanometric-auscultatory method. Standard ECG machine was used to record the electrocardiogram. Heart rate was ...

  11. Significance of left ventricular volume measurement after heart transplantation using radionuclide techniques

    International Nuclear Information System (INIS)

    Novitzky, D.; Cooper, D.; Boniaszczuk, J.

    1985-01-01

    Multigated equilibrium blood pool scanning using Technetium 99m labeled red blood cells was used to measure left ventricular volumes in three heterotopic and one orthotopic heart transplant recipient(s). Simultaneously, an endomyocardial biopsy was performed and the degree of acute rejection was assessed by a histological scoring system. The scores were correlated to changes in ejection fraction and heart rate. Technetium 99m scanning data were pooled according to the endomyocardial biopsy score: no rejection; mild rejection; moderate rejection, and severe rejection. In each group, the median of the left ventricular volume parameters was calculated and correlated with the endomyocardial biopsy score, using a non-parametric one-way analysis of variance. A decrease in stroke volume correlated best with the endomyocardial biopsy score during acute rejection. A decrease in end-diastolic left ventricular volumes did not correlate as well. Changes in the end-systolic left ventricular volumes were not statistically significant, but using a simple correlation between end-systolic left ventricular volumes and endomyocardial biopsy the correlation reached significance. Changes in left ventricular volumes measured by Technetium 99m scanning may be useful to confirm the presence or absence of acute rejection in patients with heart grafts

  12. 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.

  13. The Effect of Heart Rate on the Heart Rate Variability Response to Autonomic Interventions

    Directory of Open Access Journals (Sweden)

    George E Billman

    2013-08-01

    Full Text Available Heart rate variability (HRV, the beat-to-beat variation in either heart rate (HR or heart period (R-R interval, has become a popular clinical and investigational tool to quantify cardiac autonomic regulation. However, it is not widely appreciated that, due to the inverse curvilinear relationship between HR and R-R interval, HR per se can profoundly influence HRV. It is, therefore, critical to correct HRV for the prevailing HR particularly, as HR changes in response to autonomic neural activation or inhibition. The present study evaluated the effects of HR on the HRV response to autonomic interventions that either increased (submaximal exercise, n = 25 or baroreceptor reflex activation, n = 20 or reduced (pharmacological blockade: β-adrenergic receptor, muscarinic receptor antagonists alone and in combination, n = 25, or bilateral cervical vagotomy, n = 9 autonomic neural activity in a canine model. Both total (RR interval standard deviation, RRSD and the high frequency variability (HF, 0.2 to 1.04 Hz were determined before and in response to an autonomic intervention. All interventions that reduced or abolished cardiac parasympathetic regulation provoked large reductions in HRV even after HR correction [division by mean RRsec or (mean RRsec2 for RRSD and HF, respectively] while interventions that reduced HR yielded mixed results. β-adrenergic receptor blockade reduced HRV (RRSD but not HF while both RRSD and HF increased in response to increases in arterial blood (baroreceptor reflex activation even after HR correction. These data suggest that the physiological basis for HRV is revealed after correction for prevailing HR and, further, that cardiac parasympathetic activity is responsible for a major portion of the HRV in the dog.

  14. Cycling cadence affects heart rate variability

    International Nuclear Information System (INIS)

    Lunt, Heather C; Corbett, Jo; Barwood, Martin J; Tipton, Michael J

    2011-01-01

    The purpose of this study was to examine the effect different cycling cadences have on heart rate variability (HRV) when exercising at constant power outputs. Sixteen males had ECG and respiratory measurements recorded at rest and during 8, 10 min periods of cycling at four different cadences (40, 60, 80 and 100 revs min −1 ) and two power outputs (0 W (unloaded) and 100 W (loaded)). The cycling periods were performed following a Latin square design. Spectral analyses of R–R intervals by fast Fourier transforms were used to quantify absolute frequency domain HRV indices (ms 2 ) during the final 5 min of each bout, which were then log transformed using the natural logarithm (Ln). HRV indices of high frequency (HF) power were reduced when cadence was increased (during unloaded cycling (0 W) log transformed HF power decreased from a mean [SD] of 6.3 [1.4] Ln ms 2 at 40 revs min −1 to 3.9 [1.3] Ln ms 2 at 100 revs min −1 ). During loaded cycling (at 100 W), the low to high frequency (LF:HF) ratio formed a 'J' shaped curve as cadence increased from 40 revs min −1 (1.4 [0.4]) to 100 revs min −1 (1.9 [0.7]), but dipped below the 40 revs min −1 values during the 60 revs min −1 1.1 (0.3) and 80 revs min −1 1.2 (0.6) cadence conditions. Cardiac frequency (f C ) and ventilatory variables were strongly correlated with frequency domain HRV indices (r = −0.80 to −0.95). It is concluded that HRV indices are influenced by both cycling cadence and power output; this is mediated by the f C and ventilatory changes that occur as cadence or exercise intensity is increased. Consequently, if HRV is assessed during exercise, both power output/exercise intensity and cadence should be standardized

  15. Detailed heart rate variability analysis in athletes.

    Science.gov (United States)

    Kiss, Orsolya; Sydó, Nóra; Vargha, Péter; Vágó, Hajnalka; Czimbalmos, Csilla; Édes, Eszter; Zima, Endre; Apponyi, Györgyi; Merkely, Gergő; Sydó, Tibor; Becker, Dávid; Allison, Thomas G; Merkely, Béla

    2016-08-01

    Heart rate variability (HRV) analysis has been used to evaluate patients with various cardiovascular diseases. While the vast majority of HRV studies have focused on pathological states, our study focuses on the less explored area of HRV analysis across different training intensity and sports. We aimed to measure HRV in healthy elite and masters athletes and compare to healthy, but non-athletic controls. Time-domain HRV analysis was applied in 138 athletes (male 110, age 28.4 ± 8.3) and 100 controls (male 56, age 28.3 ± 6.9) during Holter monitoring (21.3 ± 3.0 h). All studied parameters were higher in elite athletes compared to controls [SDNN (CI) 225.3 (216.2-234.5) vs 158.6 (150.2-167.1) ms; SDNN Index (CI) 99.6 (95.6-103.7) vs 72.4 (68.7-76.2) ms; pNN50 (CI) 24.2 (22.2-26.3) vs 14.4 (12.7-16.3) %; RMSSD (CI) 71.8 (67.6-76.2) vs 50.8 (46.9-54.8) ms; p HRV values than controls, but no significant differences were found between elite athletes and masters athletes. Some parameters were higher in canoeists-kayakers and bicyclists than runners. Lower cut-off values in elite athletes were SDNN: 147.4 ms, SDNN Index: 66.6 ms, pNN50: 9.7 %, RMSSD: 37.9 ms. Autonomic regulation in elite athletes described with HRV is significantly different than in healthy controls. Sports modality and level of performance, but not age- or sex-influenced HRV. Our study provides athletic normal HRV values. Further investigations are needed to determine its role in risk stratification, optimization of training, or identifying overtraining.

  16. Altered Heart Rate Variability During Gaming in Internet Gaming Disorder.

    Science.gov (United States)

    Lee, Deokjong; Hong, Sung Jun; Jung, Young-Chul; Park, Jinsick; Kim, In Young; Namkoong, Kee

    2018-04-01

    Internet gaming disorder (IGD) is characterized by addiction to online gaming and reduced executive control, particularly when individuals are exposed to gaming-related cues. Executive control can be measured as vagally mediated heart rate variability (HRV), which corresponds to variability in the time interval between heart beats. In this study, we investigated whether individuals with IGD have altered HRV while playing online games. We hypothesized that while gaming, individuals with IGD would exhibit phasic suppression of vagally mediated HRV, which would reflect executive control dysfunction during game play. To test this, we measured the changes of HRV when young males with IGD were engaged in real-time online gaming. The changes of HRV were associated with the severity of IGD assessed by self-reports and prefrontal gray matter volume (GMV) calculated by voxel-based morphometry. We included 23 IGD subjects and 18 controls in our analyses. Changes in HRV were not statistically different between IGD subjects and controls. Within the IGD group, however, subjects showed significant decreases in high-frequency (HF) HRV during gaming. Furthermore, the degree of decrease correlated with IGD severity and prefrontal GMV. Importantly, this phasic suppression of HF-HRV in response to gaming did not occur in control subjects. In conclusion, young males with IGD showed an altered HRV response while playing an online game, reflecting their difficulties in executive control over gaming. The dynamics between executive control and reward seeking may be out of balance during game play in IGD.

  17. 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

    BACKGROUND: 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 ...

  18. 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.

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

    Science.gov (United States)

    Ackerly, Spafford C.

    2001-01-01

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

  20. Left ventricular volume during supine exercise: importance of myocardial scar in patients with coronary heart disease

    International Nuclear Information System (INIS)

    Mann, D.L.; Scharf, J.; Ahnve, S.; Gilpin, E.

    1987-01-01

    Existing studies suggest that exercise-induced ischemia produces an increase in left ventricular end-diastolic volume; however, all of these studies have included patients with previous myocardial infarction. To test whether the end-diastolic volume response to exercise is related to the extent of myocardial scar, the results of gated radionuclide supine exercise tests performed on 130 subjects were reviewed. The patient group comprised 130 subjects were reviewed. The patient group comprised 130 men aged 35 to 65 years (mean +/- SD 52 +/- 5) with documented coronary heart disease. The extent of myocardial ischemia and scar formation was assessed by stress electrocardiography and thallium-201 scintigraphy. Patients were classified into three groups on the basis of left ventricular end-diastolic volume response at peak exercise: group 1 (n = 72) had an increase of end-diastolic volume greater than 10%, group 2 (n = 41) had a change in end-diastolic volume less than 10% and group 3 (n = 17) had a decrease in end-diastolic volume greater than 10% (n = 17). At rest there was no significant difference among groups in heart rate, systolic blood pressure, end-diastolic (EDVrest) or end-systolic volumes or ejection fraction (p greater than 0.05); however, at peak exercise the end-systolic volume response was significantly greater for group 1 (p less than 0.002)

  1. "Heart rate-dependent" electrocardiographic diagnosis of left ventricular hypertrophy.

    Science.gov (United States)

    Madias, John E

    2013-05-01

    A case is presented revealing the common phenomenon of heart rate-dependent diagnosis of electrocardiographic (ECG) diagnosis of left ventricular hypertrophy (LVH), which consists of satisfaction of LVH criteria only at faster rates whereas ECGs with a slow heart rate do not satisfy such criteria. The mechanism of the phenomenon has been attributed to the tachycardia-mediated underfilling of the left ventricle bringing the electrical "centroid" of the heart closer to the recording electrodes, which results in augmentation of the amplitude of QRS complexes, particularly in leads V2-V4. ©2012, The Author. Journal compilation ©2012 Wiley Periodicals, Inc.

  2. Heating and cooling rates and their effects upon heart rate in the ...

    African Journals Online (AJOL)

    The heating and cooling rates of adult Chersina angulata were investigated to ascertain whether these tortoises can physiologically alter their rates of heat exchange. In addition, heart rates were recorded to provide an insight into the control of heat exchange. C. angulata heats significantly faster than it cools. Heart rates ...

  3. 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)....

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

    DEFF Research Database (Denmark)

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

    1999-01-01

    BACKGROUND: Cardiac complications are common during the postoperative period and may be associated with hypoxemia and tachycardia. Preliminary studies in high-risk patients after operation have shown a possible beneficial effect of oxygen therapy on arterial oxygen saturation and heart rate....... METHODS: The authors studied the effect of oxygen therapy on arterial oxygen saturation and heart rate in 100 consecutive unselected patients randomly and double blindly allocated to receive air or oxygen therapy between the first and fourth day after major abdominal surgery. RESULTS: The median arterial...... oxygen saturation rate increased significantly from 96% to 99% (P heart rate decreased significantly from 85 beats/min to 81 beats/min (P heart rate occurred...

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

    Science.gov (United States)

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

    2011-12-01

    The importance of appropriate handling of artifacts in interbeat interval (IBI) data must not be underestimated. Even a single artifact may cause unreliable heart rate variability (HRV) results. Thus, a robust artifact detection algorithm and the option for manual intervention by the researcher form key components for confident HRV analysis. Here, we present ARTiiFACT, a software tool for processing electrocardiogram and IBI data. Both automated and manual artifact detection and correction are available in a graphical user interface. In addition, ARTiiFACT includes time- and frequency-based HRV analyses and descriptive statistics, thus offering the basic tools for HRV analysis. Notably, all program steps can be executed separately and allow for data export, thus offering high flexibility and interoperability with a whole range of applications.

  6. Guided imagery, anxiety, heart rate, and heart rate variability during centrifuge training.

    Science.gov (United States)

    Jing, Xiaolu; Wu, Ping; Liu, Fang; Wu, Bin; Miao, Danmin

    2011-02-01

    Centrifuge training is an important method of improving the hypergravity tolerance of pilots, cosmonauts, and Chinese astronauts. However, the concomitants of tension or anxiety often impede training. Guided imagery (GI), a mind-body relaxation technique, provides a behavioral and cognitive means whereby individuals are able to exert control over the focus of attention. This study aims to investigate the immediate effects of GI for reducing stress in centrifuge training. There were 12 healthy young men who were randomly assigned to a GI group or music group. We measured changes in heart rate during centrifuge training, in heart rate variability before and after centrifuge training, and also evaluated relaxation and anxiety in three phases: before intervention, after intervention, and following centrifuge training. The change in the pattern of anxiety was different in the two groups over the three phases. Anxiety (measured by State Anxiety Inventory) in the GI group changed from 31.7 +/- 5.9 to 26.8 +/- 2.6 and 27.8 +/- 4.1, whereas for the music group this changed from 32.2 +/- 7.6 to 31.2 +/- 8.3 and 26.8 +/- 6.8. During centrifuge training, the maximal HR for the GI group (101.2 +/- 8.8) was lower than that of the music group (123.0 +/- 19.1). In addition GI showed a decrease in low frequency (LF, 0.04-0.15 Hz) components and an increase in high frequency (HF, 0.15-0.4 Hz) components before and after centrifuge training. GI was capable of decreasing tension, anxiety, and sympathetic nervous system activity pre- or post-centrifugation.

  7. Heart rate variability and heart rate turbulence in patients with polycystic ovary syndrome.

    Science.gov (United States)

    Özkeçeci, Gülay; Ünlü, Bekir Serdar; Dursun, Hüseyin; Akçi, Önder; Köken, Gülengül; Onrat, Ersel; Avşar, Alaettin

    2016-05-01

    Cardiac autonomic dysfunction may develop in patients with polycystic ovary syndrome (PCOS). Heart rate variability (HRV) and heart rate turbulence (HRT) are used in assessing cardiac autonomic functions. The goal of this study was to compare the cardiac autonomic functions in patients with PCOS and healthy controls. To our knowledge, this is the first study evaluating cardiac autonomic functions in patients with PCOS with respect to both HRV and HRT. Twenty-three patients with PCOS (mean age 22.8±3.9 years) and 25 healthy female volunteers who were matched for age and body mass index (BMI) (mean age 23.5±6.2 years) were enrolled in this as case-control study. Twenty-four hour ambulatory electrocardiogram recordings of all participants were taken using Pathfinder software. The time domain parameters of HRV and HRT, including turbulence onset (TO) and turbulence slope, were calculated. Diagnosis of PCOS was made with physical and laboratory findings of hirsutism or biochemical hyperandrogenism and chronic anovulation. Diabetes mellitus, other hormon disorders or hormon therapy, pregnancy, atrial fibrilation, obesite, chronic diseases, disorders of the autonomic nervous system, a history of drug use affecting the autonomic nervous system were excluded. There were no significant differences in HRV and HRT parameters between the two groups. Cardiovascular risk factors, such as BMI, blood pressure, fasting blood glucose, and lipid parameters, were also similar. Triangular index measure of HRV was negatively correlated with high density lipoprotein cholesterol levels (r=-0.47, p<0.05), while age and BMI were significantly correlated with TO (r=0.31 and 0.47, respectively; p<0.05 for all). Cardiac autonomic functions were not found to be altered in patients with PCOS in comparison with healthy controls. These results may be explained with the absence of concomitant cardiovascular risk factors with the patients being in the early stage of the disease.

  8. 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.

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

    Science.gov (United States)

    Watanabe, Ken; Ooishi, Yuuki; Kashino, Makio

    2017-03-07

    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.

  10. Intrapartum fetal heart rate profiles with and without fetal asphyxia.

    Science.gov (United States)

    Low, J A; Pancham, S R; Worthington, D N

    1977-04-01

    Fetal heart rate profiles for periods up to 12 hours prior to delivery have been reviewed in 515 patients with a fetus at risk. Mechanisms other than fetal asphyxia will cause fetal heart rate decelerations, and fetal asphyxia may in some instances develop in the absence of total or late decelerations. However, an increasing incidence of total decelerations and late decelerations and particularly a marked pattern of total decelerations and late decelerations are of value in the prediction of fetal asphyxia. Fetal heart rate deceleration patterns can predict the probability of fetal asphyxia at the time of initial intervention, while a progression of fetal heart rate deceleration patterns in the individual fetus can be of assistance in the subsequent scheduling of serial acid-base assessments during labor.

  11. The fall in the rate of death from heart diseases

    International Nuclear Information System (INIS)

    Bemski, G.

    1983-01-01

    A self limiting interaction between heart disease producing factors and genetic factors is postulated. Such an interaction could be responsable for the fall in rate of death from ischemic disease observed in the United States. (Author) [pt

  12. Effect of atrioventricular conduction on heart rate variability

    KAUST Repository

    Ahmad, Talha Jamal; Ali, Hussnain; Majeed, S. M Imran; Khan, Shoab A.

    2011-01-01

    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

  13. 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.

  14. Heart Rate Measures of Flight Test and Evaluation

    National Research Council Canada - National Science Library

    Bonner, Malcolm A; Wilson, Glenn F

    2001-01-01

    .... Because flying is a complex task, several measures are required to derive the best evaluation. This article describes the use of heart rate to augment the typical performance and subjective measures used in test and evaluation...

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

    African Journals Online (AJOL)

    DATONYE ALASIA

    Subjects with Hypertension: A Randomized Controlled Trial. Type of Article: Original ... Resting Heart Rate in Subjects with Hypertension — Lamina S. et al investigate the effect of interval .... changes in VO max) of interest. In the t-test. 2.

  16. 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.

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

    Science.gov (United States)

    Wallen, Matthew P; Gomersall, Sjaan R; Keating, Shelley E; Wisløff, Ulrik; Coombes, Jeff S

    2016-01-01

    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.

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

    OpenAIRE

    Barbero Álvarez, José Carlos; Gómez López, Maite; Barbero Álvarez, Verónica; Granda Vera, Juan; Castagna, Carlo

    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...

  19. Value of Serial Heart Rate Variability Measurement for Prediction of Appropriate ICD Discharge in Patients with Heart Failure

    NARCIS (Netherlands)

    ten Sande, Judith N.; Damman, Peter; Tijssen, Jan G. P.; de Groot, Joris R.; Knops, Reinoud E.; Wilde, Arthur A. M.; van Dessel, Pascal F. H. M.

    2014-01-01

    HRV and Appropriate ICD Shock in Heart Failure Introduction Decreased heart rate variability (HRV) is associated with adverse outcomes in patients with heart failure. Our objective was to examine whether decreased HRV predicts appropriate implantable cardioverter defibrillator (ICD) shocks. Methods

  20. 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

  1. 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.

  2. Power spectral analysis of heart rate in hyperthyroidism.

    Science.gov (United States)

    Cacciatori, V; Bellavere, F; Pezzarossa, A; Dellera, A; Gemma, M L; Thomaseth, K; Castello, R; Moghetti, P; Muggeo, M

    1996-08-01

    The aim of the present study was to evaluate the impact of hyperthyroidism on the cardiovascular system by separately analyzing the sympathetic and parasympathetic influences on heart rate. Heart rate variability was evaluated by autoregressive power spectral analysis. This method allows a reliable quantification of the low frequency (LF) and high frequency (HF) components of the heart rate power spectral density; these are considered to be under mainly sympathetic and pure parasympathetic control, respectively. In 10 newly diagnosed untreated hyperthyroid patients with Graves' disease, we analyzed power spectral density of heart rate cyclic variations at rest, while lying, and while standing. In addition, heart rate variations during deep breathing, lying and standing, and Valsalva's maneuver were analyzed. The results were compared to those obtained from 10 age-, sex-, and body mass index-matched control subjects. In 8 hyperthyroid patients, the same evaluation was repeated after the induction of stable euthyroidism by methimazole. Heart rate power spectral analysis showed a sharp reduction of HF components in hyperthyroid subjects compared to controls [lying, 13.3 +/- 4.1 vs. 32.0 +/- 5.6 normalized units (NU; P hyperthyroid subjects while both lying (11.3 +/- 4.5 vs. 3.5 +/- 1.1; P hyperthyroid patients than in controls (1.12 +/- 0.03 vs. 1.31 +/- 0.04; P activity and, thus, a relative hypersympathetic tone.

  3. Assessing positive emotional states in dogs using heart rate and heart rate variability.

    Science.gov (United States)

    Zupan, Manja; Buskas, Julia; Altimiras, Jordi; Keeling, Linda J

    2016-03-01

    Since most animal species have been recognized as sentient beings, emotional state may be a good indicator of welfare in animals. The goal of this study was to manipulate the environment of nine beagle research dogs to highlight physiological responses indicative of different emotional experiences. Stimuli were selected to be a more or a less positive food (meatball or food pellet) or social reward (familiar person or less familiar person). That all the stimuli were positive and of different reward value was confirmed in a runway motivation test. Dogs were tested individually while standing facing a display theatre where the different stimuli could be shown by lifting a shutter. The dogs approached and remained voluntarily in the test system. They were tested in four sessions (of 20s each) for each of the four stimuli. A test session consisted of four presentation phases (1st exposure to stimulus, post exposure, 2nd exposure, and access to reward). Heart rate (HR) and heart rate variability (HRV) responses were recorded during testing in the experimental room and also when lying resting in a quiet familiar room. A new method of 'stitching' short periods of HRV data together was used in the analysis. When testing different stimuli, no significant differences were observed in HR and LF:HF ratio (relative power in low frequency (LF) and the high-frequency (HF) range), implying that the sympathetic tone was activated similarly for all the stimuli and may suggest that dogs were in a state of positive arousal. A decrease of HF was associated with the meatball stimulus compared to the food pellet and the reward phase (interacting with the person or eating the food) was associated with a decrease in HF and RMSSD (root mean square of successive differences of inter-beat intervals) compared to the preceding phase (looking at the person or food). This suggests that parasympathetic deactivation is associated with a more positive emotional state in the dog. A similar reduction

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

    Science.gov (United States)

    Bair, Christine Caldwell

    2008-01-01

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

  5. Effects of Physician Volume on Readmission and Mortality in Elderly Patients with Heart Failure: Nationwide Cohort Study.

    Science.gov (United States)

    Lee, Joo Eun; Park, Eun Cheol; Jang, Suk Yong; Lee, Sang Ah; Choy, Yoon Soo; Kim, Tae Hyun

    2018-03-01

    Readmission and mortality rates of patients with heart failure are good indicators of care quality. To determine whether hospital resources are associated with care quality for cardiac patients, we analyzed the effect of number of physicians and the combined effects of number of physicians and beds on 30-day readmission and 1-year mortality. We used national cohort sample data of the National Health Insurance Service (NHIS) claims in 2002-2013. Subjects comprised 2345 inpatients (age: >65 years) admitted to acute-care hospitals for heart failure. A multivariate Cox regression was used. Of the 2345 patients hospitalized with heart failure, 812 inpatients (34.6%) were readmitted within 30 days and 190 (8.1%) had died within a year. Heart-failure patients treated at hospitals with low physician volumes had higher readmission and mortality rates than high physician volumes [30-day readmission: hazard ratio (HR)=1.291, 95% confidence interval (CI)=1.020-1.633; 1-year mortality: HR=2.168, 95% CI=1.415-3.321]. Patients admitted to hospitals with low or middle bed and physician volume had higher 30-day readmission and 1-year mortality rates than those admitted to hospitals with high volume (30-day readmission: HR=2.812, 95% CI=1.561-5.066 for middle-volume beds & low-volume physicians, 1-year mortality: HR=8.638, 95% CI=2.072-36.02 for middle-volume beds & low-volume physicians). Physician volume is related to lower readmission and mortality for heart failure. Of interest, 30-day readmission and 1-year mortality were significantly associated with the combined effects of physician and institution bed volume. © Copyright: Yonsei University College of Medicine 2018

  6. Changes in heart rate and heart rate variability as a function of age in Thoroughbred horses.

    Science.gov (United States)

    Ohmura, Hajime; Jones, James H

    2017-01-01

    We investigated changes in heart rate (HR) and HR variability as a function of age in newborn foals to old Thoroughbred horses. Experiments were performed on a total of 83 healthy and clinically normal Thoroughbred horses. Resting HR decreased with age from birth. The relationship between age and HR fit the equation Y=48.2X -0.129 (R 2 =0.705); the relationship between age and HR for horses 0-7 years old fit the equation Y=44.1X -0.179 (R 2 =0.882). Seven-day-old horses had the highest HR values (106 ± 10.3 beat/min). The low frequency (LF) and high frequency (HF) powers increased with age in newborn to old horses. These changes in HR and HR variability appear to result from the effects of ageing. Three- to seven-year-old race horses had the lowest HR values (32.9 ± 3.5 beat/min) and the highest LF and HF powers except for the HF powers in the oldest horses. Race training may have contributed to these changes. Horses of ages greater than 25 years old had the highest HF powers and the lowest LF/HF ratios. In individual horses, 8 of the 15 horses over 25 years old had LF/HF ratios of less than 1.0; their HR variability appears to be unique, and they may have a different autonomic balance than horses of younger age.

  7. Rate control management of atrial fibrillation: may a mathematical model suggest an ideal heart rate?

    Directory of Open Access Journals (Sweden)

    Matteo Anselmino

    Full Text Available 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.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.Left ventricular pressure increased by 57%, from 33.92±37.56 mmHg to 53.15±47.56 mmHg, and mean systemic arterial pressure increased by 27%, from 82.66±14.04 mmHg to 105.3±7.6 mmHg, at the 50 and 130 bpm simulations, respectively. Stroke volume (from 77.45±8.50 to 39.09±8.08 mL, ejection fraction (from 61.10±4.40 to 39.32±5.42% and stroke work (SW, from 0.88±0.04 to 0.58±0.09 J decreased by 50, 36 and 34%, at the 50 and 130 bpm simulations, respectively. In addition, oxygen consumption indexes (rate pressure product - RPP, tension time index per minute - TTI/min, and pressure volume area per minute - PVA/min increased from the 50 to the 130 bpm simulation, respectively, by 186% (from 5598±1939 to 15995±3219 mmHg/min, 56% (from 2094±265 to 3257±301 mmHg s/min and 102% (from 57.99±17.90 to 117.4±26.0 J/min. In fact, left ventricular efficiency (SW/PVA decreased from 80.91±2.91% at 50 bpm to 66.43±3.72% at the 130 bpm HR simulation.Awaiting compulsory direct clinical evidences, the present mathematical model suggests that lower HRs during permanent AF relates to improved hemodynamic parameters, cardiac efficiency, and lower oxygen consumption.

  8. Rate control management of atrial fibrillation: may a mathematical model suggest an ideal heart rate?

    Science.gov (United States)

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

    2015-01-01

    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. 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. Left ventricular pressure increased by 57%, from 33.92±37.56 mmHg to 53.15±47.56 mmHg, and mean systemic arterial pressure increased by 27%, from 82.66±14.04 mmHg to 105.3±7.6 mmHg, at the 50 and 130 bpm simulations, respectively. Stroke volume (from 77.45±8.50 to 39.09±8.08 mL), ejection fraction (from 61.10±4.40 to 39.32±5.42%) and stroke work (SW, from 0.88±0.04 to 0.58±0.09 J) decreased by 50, 36 and 34%, at the 50 and 130 bpm simulations, respectively. In addition, oxygen consumption indexes (rate pressure product - RPP, tension time index per minute - TTI/min, and pressure volume area per minute - PVA/min) increased from the 50 to the 130 bpm simulation, respectively, by 186% (from 5598±1939 to 15995±3219 mmHg/min), 56% (from 2094±265 to 3257±301 mmHg s/min) and 102% (from 57.99±17.90 to 117.4±26.0 J/min). In fact, left ventricular efficiency (SW/PVA) decreased from 80.91±2.91% at 50 bpm to 66.43±3.72% at the 130 bpm HR simulation. Awaiting compulsory direct clinical evidences, the present mathematical model suggests that lower HRs during permanent AF relates to improved hemodynamic parameters, cardiac efficiency, and lower oxygen consumption.

  9. Entropies, Partitionings and Heart Rate Variability

    Czech Academy of Sciences Publication Activity Database

    Paluš, Milan; Zebrowski, J.

    2009-01-01

    Roč. 51, č. 2 (2009), s. 65-72 ISSN 0001-7604 Institutional research plan: CEZ:AV0Z10300504 Keywords : coarse-grained entropy rate * HR variability * entropy Subject RIV: BB - Applied Statistics, Operational Research http://www.activitas.org/index.php/nervosa/article/view/25

  10. 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

  11. 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...... in healthy and hypertensive elderly people the hysteresis loop shifts to higher blood pressure values and its area is diminished. Finally, for hypertensive elderly people the hysteresis loop is generally not closed indicating that during postural change from sitting to standing, the blood pressure resettles......During orthostatic stress, arterial and cardiopulmonary baroreflexes play a key role in maintaining arterial pressure by regulating heart rate. This study, presents a mathematical model that can predict the dynamics of heart rate regulation in response to postural change from sitting to standing...

  12. The Impact of Heart Irradiation on Dose-Volume Effects in the Rat Lung

    International Nuclear Information System (INIS)

    Luijk, Peter van; Faber, Hette; Meertens, Harm; Schippers, Jacobus M.; Langendijk, Johannes A.; Brandenburg, Sytze; Kampinga, Harm H.; Coppes, Robert P. Ph.D.

    2007-01-01

    Purpose: To test the hypothesis that heart irradiation increases the risk of a symptomatic radiation-induced loss of lung function (SRILF) and that this can be well-described as a modulation of the functional reserve of the lung. Methods and Materials: Rats were irradiated with 150-MeV protons. Dose-response curves were obtained for a significant increase in breathing frequency after irradiation of 100%, 75%, 50%, or 25% of the total lung volume, either including or excluding the heart from the irradiation field. A significant increase in the mean respiratory rate after 6-12 weeks compared with 0-4 weeks was defined as SRILF, based on biweekly measurements of the respiratory rate. The critical volume (CV) model was used to describe the risk of SRILF. Fits were done using a maximum likelihood method. Consistency between model and data was tested using a previously developed goodness-of-fit test. Results: The CV model could be fitted consistently to the data for lung irradiation only. However, this fitted model failed to predict the data that also included heart irradiation. Even refitting the model to all data resulted in a significant difference between model and data. These results imply that, although the CV model describes the risk of SRILF when the heart is spared, the model needs to be modified to account for the impact of dose to the heart on the risk of SRILF. Finally, a modified CV model is described that is consistent to all data. Conclusions: The detrimental effect of dose to the heart on the incidence of SRILF can be described by a dose dependent decrease in functional reserve of the lung

  13. Volume growth rate of acoustic neurinomas

    International Nuclear Information System (INIS)

    Laasonen, E.M.; Troupp, H.

    1986-01-01

    Of 79 acoustic neurinomas seen between June 1980 and June 1984, at least two CT scans were available for each of 23 tumours (21 patients); the scans were performed at intervals of at least 6 months. The volume growth rate of the tumours was either moderate, with a volume doubling time ranging from 205 to 545 days, or slow, with a doubling time ranging from 1090 days to no observable growth. No single clinical, radiological or histological feature correlated with any type of growth rate. However, some conclusions were drawn. If a primary CT scan is negative, at least 1 year should elapse before it is worthwhile taking another scan, even though audiological findings suggest growth; after an apparently radical removal, at least 3 years should elapse before a check CT scan is worthwhile; and if a small acoustic neurinoma is diagnosed, but for some reason not operated upon, a second CT scan should be carried out 1 year later in order to reassess the case. (orig.)

  14. Heart rate measurement based on face video sequence

    Science.gov (United States)

    Xu, Fang; Zhou, Qin-Wu; Wu, Peng; Chen, Xing; Yang, Xiaofeng; Yan, Hong-jian

    2015-03-01

    This paper proposes a new non-contact heart rate measurement method based on photoplethysmography (PPG) theory. With this method we can measure heart rate remotely with a camera and ambient light. We collected video sequences of subjects, and detected remote PPG signals through video sequences. Remote PPG signals were analyzed with two methods, Blind Source Separation Technology (BSST) and Cross Spectral Power Technology (CSPT). BSST is a commonly used method, and CSPT is used for the first time in the study of remote PPG signals in this paper. Both of the methods can acquire heart rate, but compared with BSST, CSPT has clearer physical meaning, and the computational complexity of CSPT is lower than that of BSST. Our work shows that heart rates detected by CSPT method have good consistency with the heart rates measured by a finger clip oximeter. With good accuracy and low computational complexity, the CSPT method has a good prospect for the application in the field of home medical devices and mobile health devices.

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

    Directory of Open Access Journals (Sweden)

    Carlos F Henríquez

    2013-04-01

    Full Text Available 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.

  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

  17. 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…

  18. Heart Rate Monitoring in Team Sports—A Conceptual Framework for Contextualizing Heart Rate Measures for Training and Recovery Prescription

    Directory of Open Access Journals (Sweden)

    Christoph Schneider

    2018-05-01

    Full Text Available A comprehensive monitoring of fitness, fatigue, and performance is crucial for understanding an athlete's individual responses to training to optimize the scheduling of training and recovery strategies. Resting and exercise-related heart rate measures have received growing interest in recent decades and are considered potentially useful within multivariate response monitoring, as they provide non-invasive and time-efficient insights into the status of the autonomic nervous system (ANS and aerobic fitness. In team sports, the practical implementation of athlete monitoring systems poses a particular challenge due to the complex and multidimensional structure of game demands and player and team performance, as well as logistic reasons, such as the typically large number of players and busy training and competition schedules. In this regard, exercise-related heart rate measures are likely the most applicable markers, as they can be routinely assessed during warm-ups using short (3–5 min submaximal exercise protocols for an entire squad with common chest strap-based team monitoring devices. However, a comprehensive and meaningful monitoring of the training process requires the accurate separation of various types of responses, such as strain, recovery, and adaptation, which may all affect heart rate measures. Therefore, additional information on the training context (such as the training phase, training load, and intensity distribution combined with multivariate analysis, which includes markers of (perceived wellness and fatigue, should be considered when interpreting changes in heart rate indices. The aim of this article is to outline current limitations of heart rate monitoring, discuss methodological considerations of univariate and multivariate approaches, illustrate the influence of different analytical concepts on assessing meaningful changes in heart rate responses, and provide case examples for contextualizing heart rate measures using

  19. Heart Rate Monitoring in Team Sports-A Conceptual Framework for Contextualizing Heart Rate Measures for Training and Recovery Prescription.

    Science.gov (United States)

    Schneider, Christoph; Hanakam, Florian; Wiewelhove, Thimo; Döweling, Alexander; Kellmann, Michael; Meyer, Tim; Pfeiffer, Mark; Ferrauti, Alexander

    2018-01-01

    A comprehensive monitoring of fitness, fatigue, and performance is crucial for understanding an athlete's individual responses to training to optimize the scheduling of training and recovery strategies. Resting and exercise-related heart rate measures have received growing interest in recent decades and are considered potentially useful within multivariate response monitoring, as they provide non-invasive and time-efficient insights into the status of the autonomic nervous system (ANS) and aerobic fitness. In team sports, the practical implementation of athlete monitoring systems poses a particular challenge due to the complex and multidimensional structure of game demands and player and team performance, as well as logistic reasons, such as the typically large number of players and busy training and competition schedules. In this regard, exercise-related heart rate measures are likely the most applicable markers, as they can be routinely assessed during warm-ups using short (3-5 min) submaximal exercise protocols for an entire squad with common chest strap-based team monitoring devices. However, a comprehensive and meaningful monitoring of the training process requires the accurate separation of various types of responses, such as strain, recovery, and adaptation, which may all affect heart rate measures. Therefore, additional information on the training context (such as the training phase, training load, and intensity distribution) combined with multivariate analysis, which includes markers of (perceived) wellness and fatigue, should be considered when interpreting changes in heart rate indices. The aim of this article is to outline current limitations of heart rate monitoring, discuss methodological considerations of univariate and multivariate approaches, illustrate the influence of different analytical concepts on assessing meaningful changes in heart rate responses, and provide case examples for contextualizing heart rate measures using simple heuristics. To

  20. Changes in heart rate and heart rate variability during transportation of horses by road and air.

    Science.gov (United States)

    Ohmura, Hajime; Hobo, Seiji; Hiraga, Atsushi; Jones, James H

    2012-04-01

    To determine the influence of transportation by road and air on heart rate (HR) and HR variability (HRV) in horses. Animals-6 healthy horses. ECG recordings were obtained from horses before (quarantine with stall rest [Q]; 24 hours) and during a journey that included transportation by road (RT; 4.5 hours), waiting on the ground in an air stall (W; 5.5 hours), and transportation by air (AT; 11 hours); HR was determined, and HRV indices of autonomic nervous activity (low-frequency [LF; 0.01 to 0.07 Hz] and high-frequency [HF; 0.07 to 0.6 Hz] power) were calculated. Mean ± SD HRs during Q, RT, W, and AT were 38.9 ± 1.5 beats/min, 41.7 ± 5.6 beats/min, 41.5 ± 4.3 beats/min, and 48.8 ± 5.6 beats/min, respectively; HR during AT was significantly higher than HR during Q. The LF power was significantly higher during Q (3,454 ± 1,087 milliseconds(2)) and AT (3,101 ± 567 milliseconds(2)) than it was during RT (1,824 ± 432 milliseconds(2)) and W (2,072 ± 616 milliseconds(2)). During Q, RT, W, and AT, neither HF powers (range, 509 to 927 milliseconds(2)) nor LF:HF ratios (range, 4.1 to 6.2) differed significantly. The HR during RT was highly correlated with LF power (R(2) = 0.979), and HR during AT was moderately correlated with the LF:HF ratio (R(2) = 0.477). In horses, HR and HRV indices during RT and AT differed, suggesting that exposure to different stressors results in different autonomic nervous influences on HR.

  1. Grip force and heart rate responses to manual carrying tasks: effects of material, weight, and base area of the container.

    Science.gov (United States)

    Lee, Tzu-Hsien; Tseng, Chia-Yun

    2014-01-01

    This study recruited 16 industrial workers to examine the effects of material, weight, and base area of container on reduction of grip force (ΔGF) and heart rate for a 100-m manual carrying task. This study examined 2 carrying materials (iron and water), 4 carrying weights (4.4, 8.9, 13.3, 17.8 kg), and 2 base areas of container (24 × 24 cm, 35 × 24 cm). This study showed that carrying water significantly increased ΔGF and heart rate as compared with carrying iron. Also, ΔGF and heart rate significantly increased with carrying weight and base area of container. The effects of base area of container on ΔGF and heart rate were greater in carrying water condition than in carrying iron condition. The maximum dynamic effect of water on ΔGF and heart rate occurred when water occupied ~60%-80% of full volume of the container.

  2. Relationship between heart rate and preference for tempo of music.

    Science.gov (United States)

    Iwanaga, M

    1995-10-01

    People prefer music with tempi ranging from 70 to 100 cycles per minute similar to that of adults' heart rate within normal daily situations. Previous studies of the relation between preferred tempi and heart rates using a pure tone also have indicated that subjects tended to prefer tempi similar to their heart rates. The present study examined this relationship using a musical piece (the theme of "It's a small world") as a stimulus. 14 undergraduate women were subjects who searched for their favorite tempi by controlling the musical tempo by themselves. The most preferred tempo was close to their cycle of heart beats, however, tempi that were one and a half and twice as fast as the heart rate were less preferred in the present study than in a previous study using a tone. Subjects preferred faster tempi in the descending series of stimuli than in the ascending one, and hence were influenced by the initial value of the tempo in the trial sequence. The effects due to the differences of the meaning of the stimuli are considered.

  3. QRS peak detection for heart rate monitoring on Android smartphone

    Science.gov (United States)

    Pambudi Utomo, Trio; Nuryani, Nuryani; Darmanto

    2017-11-01

    In this study, Android smartphone is used for heart rate monitoring and displaying electrocardiogram (ECG) graph. Heart rate determination is based on QRS peak detection. Two methods are studied to detect the QRS complex peak; they are Peak Threshold and Peak Filter. The acquisition of ECG data is utilized by AD8232 module from Analog Devices, three electrodes, and Microcontroller Arduino UNO R3. To record the ECG data from a patient, three electrodes are attached to particular body’s surface of a patient. Patient’s heart activity which is recorded by AD8232 module is decoded by Arduino UNO R3 into analog data. Then, the analog data is converted into a voltage value (mV) and is processed to get the QRS complex peak. Heart rate value is calculated by Microcontroller Arduino UNO R3 uses the QRS complex peak. Voltage, heart rate, and the QRS complex peak are sent to Android smartphone by Bluetooth HC-05. ECG data is displayed as the graph by Android smartphone. To evaluate the performance of QRS complex peak detection method, three parameters are used; they are positive predictive, accuracy and sensitivity. Positive predictive, accuracy, and sensitivity of Peak Threshold method is 92.39%, 70.30%, 74.62% and for Peak Filter method are 98.38%, 82.47%, 83.61%, respectively.

  4. 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.

  5. Changes in heart rate variability and QT variability during the first trimester of pregnancy.

    Science.gov (United States)

    Carpenter, R E; D'Silva, L A; Emery, S J; Uzun, O; Rassi, D; Lewis, M J

    2015-03-01

    The risk of new-onset arrhythmia during pregnancy is high, presumably relating to changes in both haemodynamic and cardiac autonomic function. The ability to non-invasively assess an individual's risk of developing arrhythmia during pregnancy would therefore be clinically significant. We aimed to quantify electrocardiographic temporal characteristics during the first trimester of pregnancy and to compare these with non-pregnant controls. Ninety-nine pregnant women and sixty-three non-pregnant women underwent non-invasive cardiovascular and haemodynamic assessment during a protocol consisting of various physiological states (postural manoeurvres, light exercise and metronomic breathing). Variables measured included stroke volume, cardiac output, heart rate, heart rate variability, QT and QT variability and QTVI (a measure of the variability of QT relative to that of RR). Heart rate (p pregnancy only during the supine position (p pregnancy in all physiological states (p pregnancy in all states (p pregnancy is associated with substantial changes in heart rate variability, reflecting a reduction in parasympathetic tone and an increase in sympathetic activity. QTVI shifted to a less favourable value, reflecting a greater than normal amount of QT variability. QTVI appears to be a useful method for quantifying changes in QT variability relative to RR (or heart rate) variability, being sensitive not only to physiological state but also to gestational age. We support the use of non-invasive markers of cardiac electrical variability to evaluate the risk of arrhythmic events in pregnancy, and we recommend the use of multiple physiological states during the assessment protocol.

  6. Heart rate variability as determinism with jump stochastic parameters.

    Science.gov (United States)

    Zheng, Jiongxuan; Skufca, Joseph D; Bollt, Erik M

    2013-08-01

    We use measured heart rate information (RR intervals) to develop a one-dimensional nonlinear map that describes short term deterministic behavior in the data. Our study suggests that there is a stochastic parameter with persistence which causes the heart rate and rhythm system to wander about a bifurcation point. We propose a modified circle map with a jump process noise term as a model which can qualitatively capture such this behavior of low dimensional transient determinism with occasional (stochastically defined) jumps from one deterministic system to another within a one parameter family of deterministic systems.

  7. Heart Rate Monitor for Portable MP3 Player.

    Science.gov (United States)

    Kim, Jaywoo; Lee, Mi-Hee; Lee, Hyoung-Ki; Choi, Kiwan; Bang, Seokwon; Kim, Sangryong

    2005-01-01

    This paper presents a photoplethysmography sensor based on a heart rate monitor for a portable MP3 player. Two major design issues are addressed: one is to acquire the sensor signal with a proper amplitude despite a wide range of variation and the other is to handle the noise contaminated signal which is caused by a motion artifact. A benchmarking test with a professional medical photoplethysmography sensor shows that our device performs very well in calculating heart rate even though our photoplethysmography sensor module was designed to be cost effective.

  8. QT measurement and heart rate correction during hypoglycemia

    DEFF Research Database (Denmark)

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

    2010-01-01

    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......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...... prolongation at hypoglycemia for QTcB (42(6) ms; P measuring the QT interval has...

  9. Robust efficient estimation of heart rate pulse from video

    Science.gov (United States)

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

    2014-01-01

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

  10. 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.

  11. Functionality of the baroreceptor nerves in heart rate regulation

    DEFF Research Database (Denmark)

    Ottesen, Johnny T.; Olufsen, Mette

    2011-01-01

    are a consequence of the memory encapsulated by the models, and the nonlinearity gives rise to sigmoidal response curves. The nonlinear afferent baroreceptor models are coupled with an effector model, and the coupled model has been used to predict baroreceptor feedback regulation of heart rate during postural...... change from sitting to standing and during head-up tilt. The efferent model couples the afferent nerve paths to the sympathetic and parasympathetic outflow, and subsequently predicts the build up of an action potential at the sinus knot of the heart. In this paper, we analyze the nonlinear afferent model...... and show that the coupled model is able to predict heart rate regulation using blood pressure data as an input...

  12. Heart-Rate Recovery After Warm-up in Swimming: A Useful Predictor of Training Heart-Rate Response?

    Science.gov (United States)

    Ganzevles, Sander P M; de Haan, Arnold; Beek, Peter J; Daanen, Hein A M; Truijens, Martin J

    2017-07-01

    For training to be optimal, daily training load has to be adapted to the momentary status of the individual athlete, which is often difficult to establish. Therefore, the current study investigated the predictive value of heart-rate recovery (HRR) during a standardized warm-up for training load. Training load was quantified by the variation in heart rate during standardized training in competitive swimmers. Eight female and 5 male Dutch national-level swimmers participated in the study. They all performed 3 sessions consisting of a 300-m warm-up test and a 10 × 100-m training protocol. Both protocols were swum in front crawl at individually standardized velocities derived from an incremental step test. Velocity was related to 75% and 85% heart-rate reserve (% HR res ) for the warm-up and training, respectively. Relative HRR during the first 60 s after the warm-up (HR Rw-up ) and differences between the actual and intended heart rate for the warm-up and the training (ΔHR w-up and ΔHR tr ) were determined. No significant relationship between HRR w-up and ΔHR tr was found (F 1,37 = 2.96, P = .09, R 2 = .07, SEE = 4.65). There was considerable daily variation in ΔHR tr at a given swimming velocity (73-93% HR res ). ΔHR w-up and ΔHR tr were clearly related (F 1,37 = 74.31, P warm-up does not predict heart rate during a directly subsequent and standardized training session. Instead, heart rate during the warm-up protocol seems a promising alternative for coaches to make daily individual-specific adjustments to training programs.

  13. 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.

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

    OpenAIRE

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

    2001-01-01

    In order to assess the relative influence of age, resting heart rate (HR) and sedentary life style, heart rate variability (HRV) was studied in two different groups. The young group (YG) consisted of 9 sedentary subjects aged 15 to 20 years (YG-S) and of 9 nonsedentary volunteers (YG-NS) also aged 15 to 20. The elderly sedentary group (ESG) consisted of 16 sedentary subjects aged 39 to 82 years. HRV was assessed using a short-term procedure (5 min). R-R variability was calculated in the time-...

  15. Heart Rate Monitors Promote Physical Education for Children

    Science.gov (United States)

    Tipton, Jan; Sander, Allan N.

    2004-01-01

    National health and fitness data suggests that a significant percentage of children are not on a pathway to leading healthy, physically active lifestyles. Many children are leading sedentary lifestyles due to a lack of opportunity, success, or self-motivation in physical activity. Programs that highlight the use of heart rate monitors offer a…

  16. 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'...

  17. Early Embryonic Heart Rate in Normal Pregnancies In Memory of ...

    African Journals Online (AJOL)

    To determine the appearance and development of embryonic heart rate a total of n = 317 Nigerian pregnant women were studied in the very early pregnancy from 23 – 56 days from the onset of last menstrual period (LMP). All pregnancies had a subsequent successful outcome. Transvaginal ultrasonography was ...

  18. 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

  19. 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…

  20. Retrospective low heart rate variability overview in Jos, Nigeria ...

    African Journals Online (AJOL)

    Result: Subjects with low HRV were older (51 vs 42, p=<0.05) years with low mean heart rate p=<0.05, compared to those with normal HRV. They all had severe features of cardiac dysfunction. Females with low HRV had decreased frequency of premature atrial contraction (PACs) (52% vs 78%). Only 5 (28%) cases out of ...

  1. Heart rate variability | Lutfi | Sudan Journal of Medical Sciences

    African Journals Online (AJOL)

    An important outcome of such analysis is heart rate variability (HRV), which is widely accepted to have prognostic significance in patients with cardiovascular diseases especially after acute myocardial infarction. This is because HRV represents one of the most helpful markers of autonomic balance and hence can predict ...

  2. Heart rate variability analysis in acute poisoning by cholinesterase inhibitors

    OpenAIRE

    JEONG, JINWOO; KIM, YONGIN

    2017-01-01

    Heart rate variability (HRV) has been associated with a variety of clinical situations. However, few studies have examined the association between HRV and acute poisoning. Organophosphate (OP) and carbamate inhibit esterase enzymes, particularly acetylcholinesterase, resulting in an accumulation of acetylcholine and thereby promoting excessive activation of corresponding receptors. Because diagnosis and treatment of OP and carbamate poisoning greatly depend on...

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

    African Journals Online (AJOL)

    Background: Previous studies of autonomic nervous system activity through analysis of heart rate variability (HRV) have demonstrated increased sympathetic activity during positive-pressure pneumoperitoneum. We employed an online, continuous method for rapid HRV analysis (MemCalc™, Tarawa, Suwa Trust, Tokyo, ...

  4. 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.

  5. Anti-Hyperlipidaemic and Heart Rate Lowering Effects of Aqueous ...

    African Journals Online (AJOL)

    The anti-hyperlipidaemic and heart rate lowering potential of aqueous leaf extract of Viscum album (mistletoe) in hypercholesterolaemic rats was investigated in this study. The lethality studies showed that the aqueous extract of the plant had an LD50 value of 452.20mg/kg by intraperitoneal route. There were significant ...

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

    African Journals Online (AJOL)

    2010-07-16

    Jul 16, 2010 ... Power spectral analysis of the electrocardiographic R-R interval [heart rate variability: (HRV)] is a well known, non- invasive method for assessing autonomic nervous activity.1. Studies using HRV analysis during positive-pressure pneumoperitoneum (PPP) have demonstrated increased sympathetic ...

  7. Blood pressure and heart rate adjustment following acute Frenkel's ...

    African Journals Online (AJOL)

    Background: Frenkel's ambulatory activity has been routinely employed by physiotherapists for rehabilitation of gait coordination, however, its immediate influence on blood pressure and heart rate has not been investigated. Objective: To investigate the acute effect of Frenkel's ambulatory activity on blood pressure and ...

  8. Prediction of maximal heart rate: comparison using a novel and ...

    African Journals Online (AJOL)

    Prediction of maximal heart rate: comparison using a novel and conventional equation. LR Keytel, E Mukwevho, MA Will, M Lambert. Abstract. No Abstract. African Journal for Physical, Health Education, Recreation and Dance Vol. 11(3) 2005: 269-277. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL ...

  9. 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...

  10. 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.

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

    NARCIS (Netherlands)

    van der Does, Hendrike; Brink, Michel; Visscher, Chris; Lemmink, Koen

    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

  12. The intubating laryngeal mask produces less heart rate response to ...

    African Journals Online (AJOL)

    Pc

    We compared heart rate and blood pressure changes to intubation produced by conventional laryngoscopic-guided intubation to those produced by blind intubation through the intubating laryngeal mask (ILM) in normotensive adults with normal airways. Forty paralysed, anaesthetised adults undergoing elective surgery ...

  13. 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…

  14. Exercise and lifestyle predictors of resting heart rate in healthy young adults

    OpenAIRE

    Nealen, Paul M.

    2016-01-01

    Physical exercise is well-understood to provide significant health benefits, through physiological adaptations induced by the repeated exertion stress exercise imposes on our systems. Chief among these are cardiovascular adaptations to exercise, including adjustments of cardiac parameters such as stroke volume, heart rate, and maximal cardiac output. It is commonly assumed that aerobic forms of exercise provide greater cardiovascular benefits than do non-aerobic forms of exercise. To test thi...

  15. VASCULAR REMODELING AND HEART RATE VARIABILITY IN DIFFERENT ANTIHYPERTENSIVE THERAPIES

    Directory of Open Access Journals (Sweden)

    E. D. Golovanova

    2008-01-01

    Full Text Available Aim. To study the effect of the long-term antihypertensive monotherapy with indapamide (Arifon Retard, 1,5 mg/d, metoprolol tartrate (Egilok Retard, 50 mg/d and combined therapy with indapamide and perindopril (Noliprel Forte, 1 tab/d: perindopril 4 mg and indapamide 1,25 mg on pulse wave velocity (PWV, cardio-ankle vascular index (CAVI and the sympathetic system activity.Material and methods. 88 patients, aged 30-59 y.o. (32 normotensive patients, 56 with arterial hypertension [HT] of 1-2 grades were examined. Biological age (BA was determined by the linear regression and the vascular wall age (VWA was estimated with the use of volume sphygmography (“VaSera-1000”, “Fucuda Denshi”, Japan. 39 patients with HT were randomized into 3 parallel groups with studied therapies lasted for 6 months. PWV, CAVI of the vessels of elastic, muscular and mixed types, blood pressure, measured in upper and lower extremities and heart rate variability (HRV were determined before and at the end of the therapies.Results. BA and VWA were elevated in all of patients with HT as compared with normotensive patients. The reduction in PWV and CAVI of the vessels of elastic and mixed types, HRV increase were found in patients with Arifon Retard monotherapy. Monotherapy with metoprolol significantly improved HVR without any influence on the vascular remodeling. Noliprel Forte significantly decreased in blood pressure in the upper and lower extremities, PWV and CAVI of the vessels of all types, decreased in VWA and increased in parasympathetic drive.Conclusion. Long-term therapy with Arifon Retard and Noliprel Forte resulted in decrease in vascular remodeling and increase in HRV simultaneously with significant antihypertensive effect in patients with HT. Metoprolol low doses therapy resulted in normalization of autonomic drive independently on antihypertensive action.

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

    International Nuclear Information System (INIS)

    Kimura, Motomasa; Yamagishi, Hiroaki; Seino, Yasuyuki; Odano, Ikuo; Sakai, Kunio; Yamamoto, Tomohiko; Tsuda, Takashi

    1988-01-01

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

  17. Wavelet and receiver operating characteristic analysis of heart rate variability

    Science.gov (United States)

    McCaffery, G.; Griffith, T. M.; Naka, K.; Frennaux, M. P.; Matthai, C. C.

    2002-02-01

    Multiresolution wavelet analysis has been used to study the heart rate variability in two classes of patients with different pathological conditions. The scale dependent measure of Thurner et al. was found to be statistically significant in discriminating patients suffering from hypercardiomyopathy from a control set of normal subjects. We have performed Receiver Operating Characteristc (ROC) analysis and found the ROC area to be a useful measure by which to label the significance of the discrimination, as well as to describe the severity of heart dysfunction.

  18. Heart rate detection from an electronic weighing scale

    International Nuclear Information System (INIS)

    González-Landaeta, R; Casas, O; Pallàs-Areny, R

    2008-01-01

    We propose a novel technique for beat-to-beat heart rate detection based on the ballistocardiographic (BCG) force signal from a subject standing on a common electronic weighing scale. The detection relies on sensing force variations related to the blood acceleration in the aorta, works even if wearing footwear and does not require any sensors attached to the body because it uses the load cells in the scale. We have devised an approach to estimate the sensitivity and frequency response of three commercial weighing scales to assess their capability to detect the BCG force signal. Static sensitivities ranged from 490 nV V −1 N −1 to 1670 nV V −1 N −1 . The frequency response depended on the subject's mass but it was broad enough for heart rate estimation. We have designed an electronic pulse detection system based on off-the-shelf integrated circuits to sense heart-beat-related force variations of about 0.24 N. The signal-to-noise ratio of the main peaks of the force signal detected was higher than 30 dB. A Bland–Altman plot was used to compare the RR time intervals estimated from the ECG and BCG force signals for 17 volunteers. The error was ±21 ms, which makes the proposed technique suitable for short-term monitoring of the heart rate

  19. Automatic heart rate normalization for accurate energy expenditure normalization : an analysis of activities of daily living and heart rate features

    NARCIS (Netherlands)

    Altini, M.; Penders, J.; Vullers, R.J.M.; Amft, O.D.

    2014-01-01

    Introduction: This article is part of the Focus Theme of Methods of Information in Medicine on "Pervasive Intelligent Technologies for Health". Background: Energy Expenditure (EE) estimation algorithms using Heart Rate (HR) or a combination of accelerometer and HR data suffer from large error due to

  20. Gender differences of heart rate variability in healthy volunteers

    International Nuclear Information System (INIS)

    Saleem, S.; Majeed, S.M.I.; Khan, M.A.

    2012-01-01

    Objective: To identify the basic values of heart rate variability in Pakistani population and to verify our hypothesis that there are gender differences in cardiovascular autonomic modulation. Methods: The descriptive cross sectional study based on convenience probability sampling was conducted at Armed Forces Institute of Cardiology/National Institute of Heart Diseases (AFIC/NIHD) Pakistan. The duration of the study was from December 2009 to July 2010. It involved 24-hour holter monitoring of 45 healthy individuals using holter electrocardiography (ECG) recorder. Heart rate variability was analysed in time (SDNN, SDANN, SDNNi, rMSSD, pNN50) and frequency domains (power, VLF, LF, and HF). Results: The time domain indices; SDNN (male=140 +- 36 ms vs. females=122 +- 33 ms; p =0.09), SDANN (male=123 +- 34 ms vs. females=111+- 34 ms; P= 0.23), SDNNi (male=64 +-19 ms vs. females=52 +- 14 ms; P= 0.03), and pNN50 (male=14 +- 10 ms vs. females=12 +- 7 ms; P= 0.43) were decreased in female volunteers when compared with males. Comparison of frequency domain indices; Total power (male=4041 +- 3150 ms/sup 2/ vs. females=2750 +- 1439 ms/sup 2/; P= 0.07), VLF (male=291 2675 ms/sup 2/ vs. females=1843 +- 928 ms/sup 2/; P= 0.06), LF (male=788 +- 397 ms/sup 2/ vs. females=556 +- 346 ms/sup 2/; P= 0.04) and HF (male=318 +- 251 ms/sup 2/ vs. females=31 277 ms/sup 2/; P= 0.94) amongst males and females showed attenuated heart rate variability in females. Of all the observed values, SDNNi and LF were found significantly (p <0.05) decreased in women. Conclusion: In healthy population, heart rate variability is low in women than men. It reflects sympathetic dominance in women in our population. (author)

  1. Diminution of Heart Rate Variability in Bipolar Depression

    Directory of Open Access Journals (Sweden)

    Brandon Hage

    2017-12-01

    Full Text Available Autonomic nervous system (ANS dysregulation in depression is associated with symptoms associated with the ANS. The beat-to-beat pattern of heart rate defined as heart rate variability (HRV provides a noninvasive portal to ANS function and has been proposed to represent a means of quantifying resting vagal tone. We quantified HRV in bipolar depressed (BDD patients as a measure of ANS dysregulation seeking to establish HRV as a potential diagnostic and prognostic biomarker for treatment outcome. Forty-seven BDD patients were enrolled. They were randomized to receive either escitalopram–celecoxib or escitalopram-placebo over 8 weeks in a double-blind study design. Thirty-five patients completed the HRV studies. Thirty-six healthy subjects served as controls. HRV was assessed at pretreatment and end of study and compared with that of controls. HRV was quantified and corrected for artifacts using an algorithm that incorporates time and frequency domains to address non-stationarity of the beat-to-beat heart rate pattern. Baseline high frequency-HRV (i.e., respiratory sinus arrhythmia was lower in BDD patients than controls, although the difference did not reach significance. Baseline low-frequency HRV was significantly lower in BDD patients (ln4.20 than controls (ln = 5.50 (p < 0.01. Baseline heart period was significantly shorter (i.e., faster heart rate in BDD patients than controls. No significant change in HRV parameters were detected over the course of the study with either treatment. These findings suggest that components of HRV may be diminished in BDD patients.

  2. [The influence of physical exercise on heart rate variability].

    Science.gov (United States)

    Gajek, Jacek; Zyśko, Dorota; Negrusz-Kawecka, Marta; Halawa, Bogumił

    2003-03-01

    Heart rate variability is controlled by the influence of autonomic nervous system, whereas one part of the system modulates the activity of the other. There is evidence of increased sympathetic activity in patients (pts) with essential hypertension. The aim of the study was to assess the persisting influence of increased sympathetic activity 30 min after moderate physical exercise on heart rate variability in patients with arterial hypertension. The study was performed in 19 patients (10 women, mean age 52.7 +/- 9.5 years and 9 men, mean age 37.7 +/- 8.8 years) with stage I (6 pts) and stage II (13 pts) arterial hypertension. All studied pts had sinus rhythm, were free of diabetes, coronary heart disease and congestive heart failure. 24-hour Holter monitoring was performed and for 30 min before the exercise test the pts stayed in supine rest. The exercise tests were performed between 10 and 11 a.m. Immediately after the exercise all pts stayed in supine position for 30 min. The heart rate variability parameters were studied using Holter monitoring system Medilog Optima Jet and were then analysed statistically. The mean energy expenditure during the exercise was 5.8 +/- 1.1 METs and the maximal heart rate was 148.1 +/- 20.3 bpm. All studied HRV parameters were significantly different in the assessed time period compared to the baseline values (p < 0.001). Significant correlation was found between the age of the studied patients and the mean RR interval, what can be considered as a hyperkinetic (hyperadrenergic) circulatory status and shorter RR interval in younger pts. Significant negative correlation between the age and SDNN parameter (r = -0.65, p < 0.001), 30 min after the exercise mirrors the prolonged adrenergic influence in older pts. The present study shows that the influence of moderate physical exercise on heart rate variability in pts with essential hypertension is extended over 30 min period after exercise and is more pronounced in older pts. The studies

  3. Determination of heart rate variability with an electronic stethoscope.

    Science.gov (United States)

    Kamran, Haroon; Naggar, Isaac; Oniyuke, Francisca; Palomeque, Mercy; Chokshi, Priya; Salciccioli, Louis; Stewart, Mark; Lazar, Jason M

    2013-02-01

    Heart rate variability (HRV) is widely used to characterize cardiac autonomic function by measuring beat-to-beat alterations in heart rate. Decreased HRV has been found predictive of worse cardiovascular (CV) outcomes. HRV is determined from time intervals between QRS complexes recorded by electrocardiography (ECG) for several minutes to 24 h. Although cardiac auscultation with a stethoscope is performed routinely on patients, the human ear cannot detect heart sound time intervals. The electronic stethoscope digitally processes heart sounds, from which cardiac time intervals can be obtained. Accordingly, the objective of this study was to determine the feasibility of obtaining HRV from electronically recorded heart sounds. We prospectively studied 50 subjects with and without CV risk factors/disease and simultaneously recorded single lead ECG and heart sounds for 2 min. Time and frequency measures of HRV were calculated from R-R and S1-S1 intervals and were compared using intra-class correlation coefficients (ICC). The majority of the indices were strongly correlated (ICC 0.73-1.0), while the remaining indices were moderately correlated (ICC 0.56-0.63). In conclusion, we found HRV measures determined from S1-S1 are in agreement with those determined by single lead ECG, and we demonstrate and discuss differences in the measures in detail. In addition to characterizing cardiac murmurs and time intervals, the electronic stethoscope holds promise as a convenient low-cost tool to determine HRV in the hospital and outpatient settings as a practical extension of the physical examination.

  4. Electron-beam CT coronary angiography in the patients with high heart rate arrhythmia or pacemaker

    International Nuclear Information System (INIS)

    Dong Zhi; Zhu Jiemin; Liu Zhe; Liu Junbo; Li Youjie; Qi Ji

    2006-01-01

    Objective: To report the clinical applicability of coronary angiography for patients with high heart rate, arrhythmia or cardiac pacing using the new-generation of electron-beam CT (e-Speed). Methods: EBCT (GE e-Speed) coronary angiography was performed in 36 eases (male 27, female 9, mean age 58), including the heart rate more than 90 bpm in 20 patients, frequent ectopic beats in 11 cases, implantation of cardiac pacemaker in 4 patients and the unacceptable MSCT image quality due to variability of interscan heart rate (from 82 bpm to 104 bpm) in 1 case. After volume data set was acquired using spiral mode with prospective ECG-gating, the reconstructions of MIP, CPR, VR and Cine were performed. The VR quality was evaluated using a five-point scale. Results: The quality of coronary imaging in all of 36 cases were acceptable. The total visualization rate of coronary artery branches was 80.0%. Left main, left anterior artery and right coronary artery were visualized in all patients and in 94.3% of all cases circumflex artery were visible. Conclusion: EBCT (e-Speed) is applicable in noninvasive coronary angiography for patients with high heart rate, arrhythmia or implanted cardiac pacemaker', and this examination can obtain satisfied diagnosis. (authors)

  5. 256-slice CT coronary angiography in atrial fibrillation: The impact of mean heart rate and heart rate variability on image quality

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Liang-Kuang [Department of Radiology, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan (China); College of Medicine, Fu Jen Catholic University, Taipei, Taiwan (China); Hsu, Shih-Ming [Department of Biomedical Imaging and Radiological Science, China Medical University, Taichung, Taiwan (China); Mok, Greta S.P. [Department of Electrical and Electronics Engineering, Faculty of Science and Technology, University of Macau, Macau (China); Law, Wei-Yip; Lu, Kun-Mu [Department of Radiology, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan (China); Yang, Ching-Ching, E-mail: g39220003@yahoo.com.tw [Department of Radiological Technology, Tzu Chi College of Technology, 880, Sec.2, Chien-kuo Rd. Hualien 970, Taiwan (China); Wu, Tung-Hsin, E-mail: tung@ym.edu.tw [Department of Biomedical Imaging and Radiological Sciences, National Yang Ming University, 155 Li-Nong St., Sec. 2, Taipei 112, Taiwan (China)

    2011-08-21

    Objective: The aim of this study was to evaluate the image quality of 256-MDCT in atrial fibrillation and to compare the findings with those among patients in sinus rhythm. Materials: All reconstructed images were evaluated by two independent experienced readers blinded to patient information, heart rate, and ECG results to assess the diagnostic quality of images of the coronary artery segments using axial images, multi-planar reformations, maximum intensity projections, and volume rendering technique. Results: No statistical significance was detected in terms of the overall image quality between patients in sinus rhythm and with atrial fibrillation. Pearson's correlation analysis showed no significant association between image quality and mean heart rate no matter for patients in sinus rhythm or with atrial fibrillation. Similarly, there was no correlation between image quality and heart rate variability for either patients in sinus rhythm or with atrial fibrillation. Our results showed that the optimal reconstruction window depends on patient's HR, and the pattern for patients in atrial fibrillation is similar to that obtained from non-atrial fibrillation patients. Conclusion: This study shows the potential of using 256-MDCT coronary angiography in patients with atrial fibrillation. Our results suggest that when appropriate reconstruction timing window is applied, patients with atrial fibrillation do not have to be excluded from MDCT coronary angiographic examinations.

  6. 256-slice CT coronary angiography in atrial fibrillation: The impact of mean heart rate and heart rate variability on image quality

    International Nuclear Information System (INIS)

    Chen, Liang-Kuang; Hsu, Shih-Ming; Mok, Greta S.P.; Law, Wei-Yip; Lu, Kun-Mu; Yang, Ching-Ching; Wu, Tung-Hsin

    2011-01-01

    Objective: The aim of this study was to evaluate the image quality of 256-MDCT in atrial fibrillation and to compare the findings with those among patients in sinus rhythm. Materials: All reconstructed images were evaluated by two independent experienced readers blinded to patient information, heart rate, and ECG results to assess the diagnostic quality of images of the coronary artery segments using axial images, multi-planar reformations, maximum intensity projections, and volume rendering technique. Results: No statistical significance was detected in terms of the overall image quality between patients in sinus rhythm and with atrial fibrillation. Pearson's correlation analysis showed no significant association between image quality and mean heart rate no matter for patients in sinus rhythm or with atrial fibrillation. Similarly, there was no correlation between image quality and heart rate variability for either patients in sinus rhythm or with atrial fibrillation. Our results showed that the optimal reconstruction window depends on patient's HR, and the pattern for patients in atrial fibrillation is similar to that obtained from non-atrial fibrillation patients. Conclusion: This study shows the potential of using 256-MDCT coronary angiography in patients with atrial fibrillation. Our results suggest that when appropriate reconstruction timing window is applied, patients with atrial fibrillation do not have to be excluded from MDCT coronary angiographic examinations.

  7. Identification of heart rate-associated loci and their effects on cardiac conduction and rhythm disorders

    DEFF Research Database (Denmark)

    den Hoed, Marcel; Eijgelsheim, Mark; Esko, Tõnu

    2013-01-01

    of dilated cardiomyopathy, congenital heart failure and/or sudden cardiac death. In addition, genetic susceptibility to increased heart rate is associated with altered cardiac conduction and reduced risk of sick sinus syndrome, and both heart rate-increasing and heart rate-decreasing variants associate...

  8. 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.

  9. Heart Rate Changes in Electroacupuncture Treated Polycystic Ovary in Rats.

    Science.gov (United States)

    Ramadoss, Mukilan; Ramanathan, Gunasekaran; Subbiah, Angelie Jessica; Natrajan, Chidambaranathan

    2016-03-01

    Polycystic Ovary Syndrome (PCOS) is a common metabolic disorder, it affects both humans and animals. It may induce coronary heart disease, obesity and hyperandrogenism. Previous studies show that Low frequency Electroacupuncture (EA) have an effect on PCOS, however the exact pathway is unclear. To find the effect of EA on autonomic activity of the heart in Estradiol Valerate (EV) induced PCOS rats. Heart rate variability (HRV) was assessed in 3 groups: 1) Control; 2) PCOS rats; and 3) PCOS rats after EA treatment (n=8 in each group). From the time domain analysis and frequency domain analysis (linear measures) HRV analysis was done. EA stimulation was given at low frequency of 2Hz for 15 min on alternate days for 4-5 weeks. Collected data were statistically analysed using One-Way Analysis of Variance with the application of multiple comparisons of Tukey test. EA treatment group shows significant reduction in Heart Rate (HR) and low frequency, high frequency ratio (LF/HF); and increase in RR interval, Total Power (TP) when compared to PCOS group. The study concludes that EA treatment has a significant effect on reducing sympathetic tone and decreasing HR in PCOS.

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

    Directory of Open Access Journals (Sweden)

    Raphael Rodrigues Perim

    2011-01-01

    Full Text Available INTRODUCTION: It is unknown whether an extremely high heart rate can affect oxygen pulse profile during progressive maximal exercise in healthy subjects. OBJECTIVE: Our aim was to compare relative oxygen pulse (adjusted for body weight curves in athletes at their maximal heart rate during treadmill cardiopulmonary exercise testing. METHODS: A total of 180 elite soccer players were categorized in quartiles according to their maximum heart rate values (n = 45. Oxygen consumption, maximum heart rate and relative oxygen pulse curves in the extreme quartiles, Q1 and Q4, were compared at intervals corresponding to 10% of the total duration of a cardiopulmonary exercise testing. RESULTS: Oxygen consumption was similar among all subjects during cardiopulmonary exercise testing; however subjects in Q1 started to exhibit lower maximum heart rate values when 20% of the test was complete. Conversely, the relative oxygen pulse was higher in this group when cardiopulmonary exercise testing was 40% complete (p<.01. Although the slopes of the lines were similar (p = .25, the regression intercepts differed (p<.01 between Q1 and Q4. During the last two minutes of testing, a flat or decreasing oxygen pulse was identified in 20% of the soccer players, and this trend was similar between subjects in Q1 and Q4. CONCLUSION: Relative oxygen pulse curve slopes, which serve as an indirect and non-invasive surrogate for stroke volume, suggest that the stroke volume is similar in young and aerobically fit subjects regardless of the maximum heart rate reached.

  11. gHRV: Heart rate variability analysis made easy.

    Science.gov (United States)

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

    2014-08-01

    In this paper, the gHRV software tool is presented. It is a simple, free and portable tool developed in python for analysing heart rate variability. It includes a graphical user interface and it can import files in multiple formats, analyse time intervals in the signal, test statistical significance and export the results. This paper also contains, as an example of use, a clinical analysis performed with the gHRV tool, namely to determine whether the heart rate variability indexes change across different stages of sleep. Results from tests completed by researchers who have tried gHRV are also explained: in general the application was positively valued and results reflect a high level of satisfaction. gHRV is in continuous development and new versions will include suggestions made by testers. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  12. Association of heart rate profile during exercise with the severity of coronary artery disease.

    Science.gov (United States)

    Cay, Serkan; Ozturk, Sezgin; Biyikoglu, Funda; Yildiz, Abdulkadir; Cimen, Tolga; Uygur, Belma; Tuna, Funda

    2009-05-01

    Coronary artery disease is the leading cause of morbidity and mortality around the world. Autonomic nervous system abnormalities are associated with coronary artery disease and its complications. Exercise stress tests are routinely used for the detection of the presence of coronary artery disease. In this study, we observed the association between heart rate profile during exercise and the severity of coronary artery disease. One hundred and sixty patients with abnormal exercise treadmill test (> or =1 mm horizontal or downsloping ST-segment depression; 119 men, 41 women; mean age = 57 +/- 9 years) were included in the study. Use of any drug affecting heart rate was not permitted. Resting heart rate before exercise, maximum heart rate during exercise, and resting heart rate after exercise (5 min later) were measured and two parameters were calculated: heart rate increment (maximum heart rate - resting heart rate before exercise) and heart rate decrement (maximum heart rate - resting heart rate after exercise). All patients underwent selective coronary angiography and subclassified into two groups according to stenotic lesion severity. Group 1 had at least 50% of stenotic lesion and group 2 had less than 50%. Patients in the first group had increased resting heart rate, decreased maximum heart rate, decreased heart rate increment, and decreased heart rate decrement compared with second group. All patients were classified into tertiles of resting heart rate, heart rate increment, and heart rate decrement level to evaluate whether these parameters were associated with severity of coronary artery stenosis in the study. The multiple-adjusted odds ratio of the risk of severe coronary atherosclerosis was 21.888 (95% confidence interval 6.983-68.606) for the highest tertile of resting heart rate level compared with the lowest tertile. In addition, the multiple-adjusted odds ratio of the risk of severe coronary atherosclerosis was 20.987 (95% confidence interval 6

  13. Heart-rate variability and precompetitive anxiety in swimmers

    OpenAIRE

    Cervantes Blásquez, Julio César

    2009-01-01

    The aim of this study was to test the utility of heart-rate variability (HRV) analyses as a noninvasive means of quantifying cardiac autonomic regulation during precompetitive anxiety situations in swimmers. Psychophysiological state evaluation of 10 volunteer «master» swimmers (6 women and 4 men) was obtained by comparing baseline training condition (TC) with competition condition (CC). Self-evaluation of precompetitive somatic anxiety measured by CSAI-2 showed significant increase from the ...

  14. 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.

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

    Science.gov (United States)

    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.

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

    OpenAIRE

    Chouchou, Florian; Desseilles, Martin

    2014-01-01

    Sleep is divided into two main sleep stages: (1) non-rapid eye movement sleep (non-REMS), characterized among others by reduced global brain activity; and (2) rapid eye movement sleep (REMS), characterized by global brain activity similar to that of wakefulness. Results of heart rate variability (HRV) analysis, which is widely used to explore autonomic modulation, have revealed higher parasympathetic tone during normal non-REMS and a shift toward sympathetic predominance during normal REMS. M...

  17. Evaluation of Stress Parameters Based on Heart Rate Variability Measurements

    OpenAIRE

    Uysal, Fatma; Tokmakçı, Mahmut

    2018-01-01

    In this study, heart rate variabilitymeasurements and analysis was carried with help of the ECG recordings to showhow autonom nervous system activity changes. So as to evaluate the parametersrelated to stress of the study, the situation of relaxation, Stroop color/wordtest, mental test and auditory stimulus that would stress someone out wereapplied to six volunteer participants in a laboratory environment. Being takentotally seven minutes ECG recording and made analysis in time and frequencyd...

  18. 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.

  19. Effects of metronome breathing on the assessment of autonomic control using heart rate variability

    NARCIS (Netherlands)

    Haaksma, J; Brouwer, J; vandenBerg, MP; Dijk, WA; Dassen, WRM; Crijns, HJGM; Mulder, Lambertus; Mulder, Gysbertus

    1996-01-01

    Analysis of Heart Rate Variability is a non-invasive quantitative tool to study the influence of the autonomic nervous system on the heart. Rapid variations in heart rate, related to breathing are primarily mediated by the vagal limb of the autonomic nervous system. The resulting variations in heart

  20. 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

  1. Relationship between exercise heart rate and music tempo preference

    OpenAIRE

    Karageorghis, CI; Jones, L; Low, DC

    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 undergraduates (M 3 age = 20.0 years, SD = 0.9 years) were surveyed to establish their three favorite music artists of all time. A separate experimental group of 29 undergraduates (M age = 20.3 years, SD = 1.2 years) selected the music of a single artist from a choice of the three highest-rated artists from the earlier survey. ...

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

    Science.gov (United States)

    Arras, Margarete; Rettich, Andreas; Cinelli, Paolo; Kasermann, Hans P; Burki, Kurt

    2007-01-01

    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. PMID:17683523

  3. 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.

  4. 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

  5. Heart rate variability changes in physicians working on night call.

    Science.gov (United States)

    Malmberg, Birgitta; Persson, Roger; Flisberg, Per; Ørbaek, Palle

    2011-03-01

    Adverse effects by night-call duty have become an important occupational health issue. The aim of this study was to investigate whether the heart rate variability (HRV) differed during recovery from day work and night-call duty between distinct physician specialities. We studied the impact of a 16-h night-call duty on autonomic balance, measured by HRV, among two physician groups differing with respect to having to deal with life-threatening conditions while on call. Nineteen anaesthesiologists (ANEST) and 16 paediatricians and ear, nose and throat surgeons (PENT) were monitored by ambulatory digital Holter electrocardiogram (ECG). Heart rate variability was analysed between 21:00 and 22:00 after an ordinary workday, on night call and in the evening post-call. Absolute and normalized high-frequency power (HF, HFnu) were the main outcome variables, expressing parasympathetic influence on the heart. ANEST had lower HF power than PENT while on night call and post-daytime work (p work compared with post-night-call duty (p balance and did not differ between specialities. However, the less dynamic HRV after daytime work and during night-call duty in the ANEST group may indicate a higher physiological stress level. These results may contribute to the improvement of night-call schedules within the health care sector.

  6. 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

    2017-06-01

    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. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Heart rate variability alters cardiac repolarization and electromechanical dynamics.

    Science.gov (United States)

    Phadumdeo, Vrishti M; Weinberg, Seth H

    2018-04-07

    Heart rate continuously varies due to autonomic regulation, stochasticity in pacemaking, and circadian rhythm, collectively termed heart rate variability (HRV), during normal physiological conditions. Low HRV is clinically associated with an elevated risk of cardiac arrhythmias. Alternans, a beat-to-beat alternation in action potential duration (APD) and/or intracellular calcium (Ca) transient, is a well-known risk factor associated with cardiac arrhythmias that is typically studied under conditions of a constant pacing rate, i.e., the absence of HRV. In this study, we investigate the effects of HRV on the interplay between APD, Ca, and electromechanical properties, employing a nonlinear discrete-time map model that governs APD and intracellular Ca cycling with a stochastic pacing period. We find that HRV can decrease variation in APD and peak Ca at fast pacing rates for which alternans is present. Further, increased HRV typically disrupts the alternating pattern for both APD and peak Ca and weakens the correlation between APD and peak Ca, thus decoupling Ca-mediated instabilities from repolarization alternation. We find that the efficacy of these effects is regulated by the sarcoplasmic reticulum Ca uptake rate. Overall, these results demonstrate that HRV disrupts arrhythmogenic alternans and suggests that HRV may be a significant factor in preventing life-threatening arrhythmias. Copyright © 2018 Elsevier Ltd. All rights reserved.

  8. Non-contact Real-time heart rate measurements based on high speed circuit technology research

    Science.gov (United States)

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

    2015-08-01

    In recent years, morbidity and mortality of the cardiovascular or cerebrovascular disease, which threaten human health greatly, increased year by year. Heart rate is an important index of these diseases. To address this status, the paper puts forward a kind of simple structure, easy operation, suitable for large populations of daily monitoring non-contact heart rate measurement. In the method we use imaging equipment video sensitive areas. The changes of light intensity reflected through the image grayscale average. The light change is caused by changes in blood volume. We video the people face which include the sensitive areas (ROI), and use high-speed processing circuit to save the video as AVI format into memory. After processing the whole video of a period of time, we draw curve of each color channel with frame number as horizontal axis. Then get heart rate from the curve. We use independent component analysis (ICA) to restrain noise of sports interference, realized the accurate extraction of heart rate signal under the motion state. We design an algorithm, based on high-speed processing circuit, for face recognition and tracking to automatically get face region. We do grayscale average processing to the recognized image, get RGB three grayscale curves, and extract a clearer pulse wave curves through independent component analysis, and then we get the heart rate under the motion state. At last, by means of compare our system with Fingertip Pulse Oximeter, result show the system can realize a more accurate measurement, the error is less than 3 pats per minute.

  9. 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.

  10. 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

  11. Does Exchange Rate Volatility Affect Korea's Seaborne Import Volume?

    Directory of Open Access Journals (Sweden)

    Chang Beom Kim

    2017-03-01

    Full Text Available This study used monthly data from 2000 to 2015 to analyze the effects of USD/KRW exchange rate volatility on seaborne import volume in Korea. The results of an autoregressive distributed lag (ARDL analysis indicate that USD/KRW exchange rate volatility has a statistically significant negative influence on Korea's seaborne import volume. Moreover, the results of a vector error correction model (VECM analysis found that the USD/KRW exchange rate volatility exhibited short-term unidirectional causality on import volume and real income, and confirmed bidirectional causality between the real effective exchange rate and exchange rate volatility.

  12. Volume of myocardium perfused by coronary artery branches as estimated from 3D micro-CT images of rat hearts

    Science.gov (United States)

    Lund, Patricia E.; Naessens, Lauren C.; Seaman, Catherine A.; Reyes, Denise A.; Ritman, Erik L.

    2000-04-01

    Average myocardial perfusion is remarkably consistent throughout the heart wall under resting conditions and the velocity of blood flow is fairly reproducible from artery to artery. Based on these observations, and the fact that flow through an artery is the product of arterial cross-sectional area and blood flow velocity, we would expect the volume of myocardium perfused to be proportional to the cross-sectional area of the coronary artery perfusing that volume of myocardium. This relationship has been confirmed by others in pigs, dogs and humans. To test the body size-dependence of this relationship we used the hearts from rats, 3 through 25 weeks of age. The coronary arteries were infused with radiopaque microfil polymer and the hearts scanned in a micro- CT scanner. Using these 3D images we measured the volume of myocardium and the arterial cross-sectional area of the artery that perfused that volume of myocardium. The average constant of proportionality was found to be 0.15 +/- 0.08 cm3/mm2. Our data showed no statistically different estimates of the constant of proportionality in the rat hearts of different ages nor between the left and right coronary arteries. This constant is smaller than that observed in large animals and humans, but this difference is consistent with the body mass-dependence on metabolic rate.

  13. Relationship between stroke volume, cardiac output and filling of the heart during tilt

    DEFF Research Database (Denmark)

    Bundgaard-Nielsen, M.; Sorensen, H.; Dalsgaard, M.

    2009-01-01

    . With the supine resting position as a reference, we assessed stroke volume (SV), cardiac output (CO) and filling of the heart during graded tilt to evaluate whether SV and CO are maintained during an assumed maximal physiological filling of the heart elicited by 90 degrees HDT in healthy resting humans. METHODS...

  14. Using a smartphone to measure heart rate changes during relived happiness and anger

    NARCIS (Netherlands)

    Lakens, D.

    2013-01-01

    This study demonstrates the feasibility of measuring heart rate differences associated with emotional states such as anger and happiness with a smartphone. Novice experimenters measured higher heart rates during relived anger and happiness (replicating findings in the literature) outside a

  15. Adaptive Mean and Trend Removal of Heart Rate Variability Using Kalman Filtering

    National Research Council Canada - National Science Library

    Schloegl, A

    2001-01-01

    Analysis of heart rate van ability requires the calculation of the mean heart rate, Adaptive methods are important for online and real-time parameter estimation, In this paper we demonstrate the use...

  16. 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

  17. Cardiothoracic ratio on chest radiograph in pediatric heart disease: How does it correlate with heart volumes at magnetic resonance imaging?

    Energy Technology Data Exchange (ETDEWEB)

    Grotenhuis, Heynric B. [The University of Toronto, Division of Cardiology, Department of Paediatrics, The Labatt Family Heart Centre, The Hospital for Sick Children, Toronto (Canada); Zhou, Cheng; Isaac, Kathryn V. [The University of Toronto, Department of Diagnostic Imaging, The Hospital for Sick Children, Toronto (Canada); Tomlinson, George [University of Toronto, Department of Medicine, Toronto General Hospital and Mt. Sinai Hospital, Toronto (Canada); Seed, Mike; Grosse-Wortmann, Lars; Yoo, Shi-Joon [The University of Toronto, Division of Cardiology, Department of Paediatrics, The Labatt Family Heart Centre, The Hospital for Sick Children, Toronto (Canada); The University of Toronto, Department of Diagnostic Imaging, The Hospital for Sick Children, Toronto (Canada)

    2015-10-15

    The cardiothoracic ratio by chest radiograph is widely used as a marker of cardiac size. The purpose of this study is to correlate cardiothoracic ratio and cardiac volumes as measured by cardiovascular magnetic resonance (MR) in common structural and myopathic heart disease with increased cardiac size due to volume overload or hypertrophy. A retrospective single center study was performed in all patients between 2007 and 2013 with repaired tetralogy of Fallot (TOF), aortic regurgitation, isolated left-to-right shunt and hypertrophic cardiomyopathy (HCM) who underwent cardiovascular MR and chest radiograph within 6 months of each other. Cardiothoracic ratios by chest radiograph (frontal and lateral) were compared to cardiac volumes (indexed for body surface area) by cardiovascular MR. One hundred twenty-seven patients (mean age: 11.2 ± 5.5 years) were included in this study (76 with TOF, 23 with isolated left-to-right shunt, 16 with aortic regurgitation and 12 with HCM). Frontal cardiothoracic ratio of all groups correlated with indexed right ventricular (RV) end-diastolic volume (EDVI) (r = 0.40, P < 0.01) and indexed total heart volume (THVI) (r = 0.27, P < 0.01). In TOF patients, frontal cardiothoracic ratio correlated with RVEDVI (r = 0.34, P < 0.01; coefficient of variation = 27.6%), indexed RV end-systolic volume (ESVI) (r = 0.44, P < 0.01; coefficient of variation = 33.3%) and THVI (r = 0.35, P < 0.01; coefficient of variation = 19.6%), although RV volumes and THVI showed widespread variation given the high coefficients of variation. In patients with aortic regurgitation, frontal cardiothoracic ratio correlated with left ventricular (LV) EDVI (r = 0.50, P = 0.047), but not with THVI and aortic regurgitant fraction, and widespread variation for LV EDVI (coefficient of variation = 19.2%), LV ESVI (coefficient of variation = 32.5%) and THVI (coefficient of variation = 13.6%) was also observed. Frontal cardiothoracic ratio was not correlated with cardiac volumes

  18. 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

  19. Improved detection of congestive heart failure via probabilistic symbolic pattern recognition and heart rate variability metrics.

    Science.gov (United States)

    Mahajan, Ruhi; Viangteeravat, Teeradache; Akbilgic, Oguz

    2017-12-01

    A timely diagnosis of congestive heart failure (CHF) is crucial to evade a life-threatening event. This paper presents a novel probabilistic symbol pattern recognition (PSPR) approach to detect CHF in subjects from their cardiac interbeat (R-R) intervals. PSPR discretizes each continuous R-R interval time series by mapping them onto an eight-symbol alphabet and then models the pattern transition behavior in the symbolic representation of the series. The PSPR-based analysis of the discretized series from 107 subjects (69 normal and 38 CHF subjects) yielded discernible features to distinguish normal subjects and subjects with CHF. In addition to PSPR features, we also extracted features using the time-domain heart rate variability measures such as average and standard deviation of R-R intervals. An ensemble of bagged decision trees was used to classify two groups resulting in a five-fold cross-validation accuracy, specificity, and sensitivity of 98.1%, 100%, and 94.7%, respectively. However, a 20% holdout validation yielded an accuracy, specificity, and sensitivity of 99.5%, 100%, and 98.57%, respectively. Results from this study suggest that features obtained with the combination of PSPR and long-term heart rate variability measures can be used in developing automated CHF diagnosis tools. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Lung and heart dose volume analyses with CT simulator in tangential field irradiation of breast cancer

    International Nuclear Information System (INIS)

    Das, Indra J.; Cheng, Elizabeth C.; Fowble, Barbara

    1997-01-01

    Objective: Radiation pneumonitis and cardiac effects are directly related to the irradiated lung and heart volumes in the treatment fields. The central lung distance (CLD) from a tangential breast radiograph is shown to be a significant indicator of ipsilateral irradiated lung volume based on empirically derived functions which accuracy depends on the actual measured volume in treatment position. A simple and accurate linear relationship with CLD and retrospective analysis of the pattern of dose volume of lung and heart is presented with actual volume data from a CT simulator in the treatment of breast cancer. Materials and Methods: The heart and lung volumes in the tangential treatment fields were analyzed in 45 consecutive (22 left and 23 right breast) patients referred for CT simulation of the cone down treatment. All patients in this study were immobilized and placed on an inclined breast board in actual treatment setup. Both arms were stretched over head uniformly to avoid collision with the scanner aperture. Radiopaque marks were placed on the medial and lateral borders of the tangential fields. All patients were scanned in spiral mode with slice width and thickness of 3 mm each, respectively. The lung and heart structures as well as irradiated areas were delineated on each slice and respective volumes were accurately measured. The treatment beam parameters were recorded and the digitally reconstructed radiographs (DRRs) were generated for the CLD and analysis. Results: Table 1 shows the volume statistics of patients in this study. There is a large variation in the lung and heart volumes among patients. Due to differences in the shape of right and left lungs the percent irradiated volume (PIV) are different. The PIV data have shown to correlate with CLD with 2nd and 3rd degree polynomials; however, in this study a simple straight line regression is used to provide better confidence than the higher order polynomial. The regression lines for the left and right

  1. Relationship between exercise heart rate and music tempo preference.

    Science.gov (United States)

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

    2006-06-01

    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 = 20.3 years, SD = 1.2) selected the music of a single artist from the three highest-rated artists from the earlier survey. They reported their preference for slow, medium, and fast tempo selections from each artist for three treadmill walking conditions at 40%, 60%, and 75% maximal heart rate reserve. A mixed-model 3 x 3 x 2 (Exercise Intensity x Music Tempo x Gender) analysis of variance was used to analyze the data. Results indicated there was no three-way interaction for music preference. There was, however, a significant (p Music Tempo (partial eta2 = .09) and a significant (p effect for music tempo, with large differences evident between preference for medium versus slow tempo and fast versus slow tempo music at all exercise intensities (partial eta2 = .78). Participants reported a preference for both medium and fast tempo music at low and moderate exercise intensities and for fast tempo music at high intensity. Only partial support was found for the expected linear relationship between exercise intensity and music tempo preference.

  2. Correlated and uncorrelated heart rate fluctuations during relaxing visualization

    Science.gov (United States)

    Papasimakis, N.; Pallikari, F.

    2010-05-01

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

  3. Heart rate variability among caregivers of chronically bedridden patients

    Directory of Open Access Journals (Sweden)

    Amrith Pakkala

    2013-01-01

    Full Text Available Background: Caregivers of chronically bedridden patients are likely to suffer from mental and physical exhaustion leading to stress. This is important in view of the prevailing socioeconomic as well as the healthcare system available in a developing country like India. Therefore, the present study is designed to measure heart rate variability (HRV among this special group of population who give care to long-term bedridden patients. Materials and Methods: Fifteen female subjects were enrolled from among attendants of patients admitted with an immediate history of a cerebrovascular accident with locomotor deficits, who required constant care. They were free from any type of physical and mental health issues, nonsmokers and nonaddicts. Each care giver was subjected to HRV analysis on three occasions: The first record was performed in the 1 st week of their arrival in the hospital as caregivers. The second observation was recorded after 3 months of caregiving. The final HRV analysis was done after 6 months of care giving. Two types of parameters were analyzed: Time domain and frequency domain. Statistical analysis was done using paired t-test. Results: Both the HRV parameters: Time and frequency domain, showed decreased values during the 3 rd and 6 th month recording as compared to the 1 st week recording. The decrease is much more during the 6 th month recording as compared to the 3 rd month recording. Statistically significant decrease is observed in mean RR interval, heart rate, very low frequency (VLF, and LF only when the 1 st week recording is compared with the 3 rd month recording, but when the 1 st week recording was compared with the 6 th month recording significant decrease was found in mean RR interval and heart rate. Conclusion: Subjects involved in taking care of chronically ill bedridden patients are likely to undergo a lot of physical and mental stress, thus affecting their autonomic status. HRV analysis using short term

  4. 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

  5. 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.

  6. Entertainment Capture through Heart Rate Activity in Physical Interactive Playgrounds

    DEFF Research Database (Denmark)

    Yannakakis, Georgios; Hallam, John; Lund, Henrik Hautop

    2008-01-01

    children’s physiological signals, an estimator of the degree to which games provided by the playground engage the players. For this purpose children’s heart rate (HR) signals, and their expressed preferences of how much “fun” particular game variants are, are obtained from experiments using games...... that predict reported entertainment preferences given HR features. These models are expressed as artificial neural networks and are demonstrated and evaluated on two Playware games and two control tasks requiring physical activity. The best network is able to correctly match expressed preferences in 64...

  7. 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…

  8. A randomised, simulated study assessing auscultation of heart rate at birth

    NARCIS (Netherlands)

    Voogdt, Kevin G. J. A.; Morrison, Allison C.; Wood, Fiona E.; van Elburg, Ruurd M.; Wyllie, Jonathan P.

    2010-01-01

    Heart rate is a primary clinical indicator directing newborn resuscitation. The time taken to assess the heart rate by auscultation in relation to accuracy during newborn resuscitation is not known. To assess both the accuracy and time taken to assess heart rate by stethoscope in simulated

  9. Mercury Exposure and Heart Rate Variability: A Systematic Review

    Science.gov (United States)

    Gribble, Matthew O.; Cheng, Alan; Berger, Ronald D.; Rosman, Lori; Guallar, Eliseo

    2015-01-01

    Background Mercury affects the nervous system and has been implicated in altering heart rhythm and function. We sought to better define its role in modulating heart rate variability, a well-known marker of cardiac autonomic function. Design Systematic review. Methods We searched PubMed, Embase, TOXLINE and DART databases without language restriction. We report findings as a qualitative systematic review because heterogeneity in study design and assessment of exposures and outcomes across studies, as well as other methodological limitations of the literature, precluded a quantitative meta-analysis. Results We identified 12 studies of mercury exposure and heart rate variability in human populations (10 studies involving primarily environmental methylmercury exposure and two studies involving occupational exposure to inorganic mercury) conducted in Japan, the Faroe Islands, Canada, Korea, French Polynesia, Finland and Egypt. The association of prenatal mercury exposure with lower high-frequency band scores (thought to reflect parasympathetic activity) in several studies, in particular the inverse association of cord blood mercury levels with the coefficient of variation of the R-R intervals and with low frequency and high frequency bands at 14 years of age in the Faroe Islands birth cohort study, suggests that early mercury exposure could have a long-lasting effect on cardiac parasympathetic activity. Studies with later environmental exposures to mercury in children or in adults were heterogeneous and did not show consistent associations. Conclusions The evidence was too limited to draw firm causal inferences. Additional research is needed to elucidate the effects of mercury on cardiac autonomic function, particularly as early-life exposures might have lasting impacts on cardiac parasympathetic function. PMID:26231507

  10. 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.

  11. Maximal heart rate does not limit cardiovascular capacity in healthy humans

    DEFF Research Database (Denmark)

    Munch, G D W; Svendsen, J H; Damsgaard, R

    2014-01-01

    In humans, maximal aerobic power (VO2 max ) is associated with a plateau in cardiac output (Q), but the mechanisms regulating the interplay between maximal heart rate (HRmax) and stroke volume (SV) are unclear. To evaluate the effect of tachycardia and elevations in HRmax on cardiovascular function...... and capacity during maximal exercise in healthy humans, 12 young male cyclists performed incremental cycling and one-legged knee-extensor exercise (KEE) to exhaustion with and without right atrial pacing to increase HR. During control cycling, Q and leg blood flow increased up to 85% of maximal workload (WLmax...... and RAP (P healthy...

  12. Effect of Smoking on Blood Pressure and Resting Heart Rate

    DEFF Research Database (Denmark)

    Linneberg, Allan; Jacobsen, Rikke K; Skaaby, Tea

    2015-01-01

    BACKGROUND: -Smoking is an important cardiovascular disease risk factor, but the mechanisms linking smoking to blood pressure are poorly understood. METHODS AND RESULTS: -Data on 141,317 participants (62,666 never, 40,669 former, 37,982 current smokers) from 23 population-based studies were...... for smoking heaviness in current smokers. In observational analyses, current as compared with never smoking was associated with lower SBP, DBP, and lower hypertension risk, but with higher resting heart rate. In observational analyses amongst current smokers, one cigarette/day higher level of smoking...... heaviness was associated with higher (0.21 beats/minute; 95% CI 0.19; 0.24) resting heart rate, and slightly higher DBP (0.05 mmHg; 95% CI 0.02; 0.08) and SBP (0.08 mmHg; 95% CI 0.03; 0.13). However, in MR analyses amongst current smokers, while each smoking increasing allele of rs16969968/rs1051730...

  13. 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 HRV indices were similar between ME and MC groups. However, after training, the ME group significantly (all P 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.

  14. Smartphone-based photoplethysmographic imaging for heart rate monitoring.

    Science.gov (United States)

    Alafeef, Maha

    2017-07-01

    The purpose of this study is to make use of visible light reflected mode photoplethysmographic (PPG) imaging for heart rate (HR) monitoring via smartphones. The system uses the built-in camera feature in mobile phones to capture video from the subject's index fingertip. The video is processed, and then the PPG signal resulting from the video stream processing is used to calculate the subject's heart rate. Records from 19 subjects were used to evaluate the system's performance. The HR values obtained by the proposed method were compared with the actual HR. The obtained results show an accuracy of 99.7% and a maximum absolute error of 0.4 beats/min where most of the absolute errors lay in the range of 0.04-0.3 beats/min. Given the encouraging results, this type of HR measurement can be adopted with great benefit, especially in the conditions of personal use or home-based care. The proposed method represents an efficient portable solution for HR accurate detection and recording.

  15. Temporal discounting and heart rate reactivity to stress.

    Science.gov (United States)

    Diller, James W; Patros, Connor H G; Prentice, Paula R

    2011-07-01

    Temporal discounting is the reduction of the value of a reinforcer as a function of increasing delay to its presentation. Impulsive individuals discount delayed consequences more rapidly than self-controlled individuals, and impulsivity has been related to substance abuse, gambling, and other problem behaviors. A growing body of literature has identified biological correlates of impulsivity, though little research to date has examined relations between delay discounting and markers of poor health (e.g., cardiovascular reactivity to stress). We evaluated the relation between one aspect of impulsivity, measured using a computerized temporal discounting task, and heart rate reactivity, measured as a change in heart rate from rest during a serial subtraction task. A linear regression showed that individuals who were more reactive to stress responded more impulsively (i.e., discounted delayed reinforcers more rapidly). When results were stratified by gender, the effect was observed for females, but not for males. This finding supports previous research on gender differences in cardiovascular reactivity and suggests that this type of reactivity may be an important correlate of impulsive behavior. Copyright © 2011 Elsevier B.V. All rights reserved.

  16. 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.

  17. 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.

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

    Directory of Open Access Journals (Sweden)

    E.R. Migliaro

    2001-04-01

    Full Text Available In order to assess the relative influence of age, resting heart rate (HR and sedentary life style, heart rate variability (HRV was studied in two different groups. The young group (YG consisted of 9 sedentary subjects aged 15 to 20 years (YG-S and of 9 nonsedentary volunteers (YG-NS also aged 15 to 20. The elderly sedentary group (ESG consisted of 16 sedentary subjects aged 39 to 82 years. HRV was assessed using a short-term procedure (5 min. R-R variability was calculated in the time-domain by means of the root mean square successive differences. Frequency-domain HRV was evaluated by power spectrum analysis considering high frequency and low frequency bands. In the YG the effort tolerance was ranked in a bicycle stress test. HR was similar for both groups while ESG showed a reduced HRV compared with YG. Within each group, HRV displayed a negative correlation with HR. Although YG-NS had better effort tolerance than YG-S, their HR and HRV were not significantly different. We conclude that HRV is reduced with increasing HR or age, regardless of life style. The results obtained in our short-term study agree with others of longer duration by showing that age and HR are the main determinants of HRV. Our results do not support the idea that changes in HRV are related to regular physical activity.

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

    Science.gov (United States)

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

    2001-04-01

    In order to assess the relative influence of age, resting heart rate (HR) and sedentary life style, heart rate variability (HRV) was studied in two different groups. The young group (YG) consisted of 9 sedentary subjects aged 15 to 20 years (YG-S) and of 9 nonsedentary volunteers (YG-NS) also aged 15 to 20. The elderly sedentary group (ESG) consisted of 16 sedentary subjects aged 39 to 82 years. HRV was assessed using a short-term procedure (5 min). R-R variability was calculated in the time-domain by means of the root mean square successive differences. Frequency-domain HRV was evaluated by power spectrum analysis considering high frequency and low frequency bands. In the YG the effort tolerance was ranked in a bicycle stress test. HR was similar for both groups while ESG showed a reduced HRV compared with YG. Within each group, HRV displayed a negative correlation with HR. Although YG-NS had better effort tolerance than YG-S, their HR and HRV were not significantly different. We conclude that HRV is reduced with increasing HR or age, regardless of life style. The results obtained in our short-term study agree with others of longer duration by showing that age and HR are the main determinants of HRV. Our results do not support the idea that changes in HRV are related to regular physical activity.

  20. Heart Rate and Initial Presentation of Cardiovascular Diseases (Caliber)

    Science.gov (United States)

    2013-09-17

    Abdominal Aortic Aneurysm; Coronary Heart Disease NOS; Unheralded Coronary Death; Intracerebral Haemorrhage; Heart Failure; Ischemic Stroke; Myocardial Infarction; Stroke; Peripheral Arterial Disease; Stable Angina Pectoris; Subarachnoid Haemorrhage; Transient Ischemic Attack; Unstable Angina; Cardiac Arrest, Sudden Cardiac Death

  1. The order and volume fill rates in inventory control systems

    DEFF Research Database (Denmark)

    Thorstenson, Anders; Larsen, Christian

    2011-01-01

    This paper differentiates between an order (line) fill rate and a volume fill rate and specifies their performance for different inventory control systems. When the focus is on filling complete customer orders rather than total quantities the order fill rate would be the preferred service level m...

  2. Increased ANF secretion after volume expansion is preserved in rats with heart failure

    International Nuclear Information System (INIS)

    Chien, Young Wei; Barbee, R.W.; MacPhee, A.L.; Frohlich, E.D.; Trippodo, N.C.

    1988-01-01

    To examine whether the failing heart has reached a maximal capacity to increase plasma atrial natriuretic factor (ANF) concentration, the change in plasma immunoreactive ANF, measured by radioimmunoassay level due to acute blood volume expansion was determined in conscious rats with chronic heart failure. Varying degrees of myocardial infarction and thus heart failure were induced by coronary artery ligation 3 wk before study. Compared with controls, infarcted rats had decreases in mean arterial pressure cardiac index, renal blood flow, and peak left ventricle-developed pressure after aortic occlusion, and increases in central venous pressure, left ventricular end-diastolic pressure, total peripheral resistance, plasma ANF level. Plasma ANF was correlated with infarct size, cardiac filling pressures, and left ventricle pressure-generating ability. At 5 min after 25% blood volume expansion, plasma ANF in rats with heart failure increased by 2,281 ± 345 pg/ml; the magnitude of the changes in circulating ANF and hemodynamic measurements was similar in controls. The results suggest that plasma ANF level can be used as a reliable index of the severity of heart failure, and that the capacity to increase plasma ANF concentration after acute volume expansion is preserved in rats with heart failure. There was no evidence of a relative deficiency of circulating ANF in this model of heart failure

  3. 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.

  4. The role of heart rate variability in sports physiology.

    Science.gov (United States)

    Dong, Jin-Guo

    2016-05-01

    Heart rate variability (HRV) is a relevant marker reflecting cardiac modulation by sympathetic and vagal components of the autonomic nervous system (ANS). Although the clinical application of HRV is mainly associated with the prediction of sudden cardiac death and assessing cardiovascular and metabolic illness progression, recent observations have suggested its applicability to physical exercise training. HRV is becoming one of the most useful tools for tracking the time course of training adaptation/maladaptation of athletes and in setting the optimal training loads leading to improved performances. However, little is known regarding the role of HRV and the internal effects of physical exercise on an athlete, which may be useful in designing fitness programs ensuring sufficient training load that may correspond with the specific ability of the athlete. In this review, we offer a comprehensive assessment of investigations concerning the interrelation between HRV and ANS, and examine how the application of HRV to physical exercise may play a role in sports physiology.

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

    Science.gov (United States)

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

    2014-01-01

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

  6. 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.

  7. 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

    ) conditions, but attenuated with β-adrenergic blockade (0.2 ± 1 beats min(-1); P > 0.05 vs. rest). Thus muscle metaboreflex activation-mediated increases in HR are principally attributable to increased cardiac sympathetic activity, and only following exercise with a large muscle mass (PEI following leg......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...... exercise, (2) isolated muscle metaboreflex activation (post-exercise ischaemia; PEI) following leg cycling exercise, (3) isometric handgrip followed by PEI. Trials were undertaken under control (no drug), β1-adrenergic blockade (metoprolol) and parasympathetic blockade (glycopyrrolate) conditions. HR...

  8. Resting Heart Rate Is Not Associated with Cognitive Function

    DEFF Research Database (Denmark)

    Wod, M; Jensen, M T; Galatius, S

    2018-01-01

    Aims: In order to examine the hypothesis that elevated resting heart rate (RHR) is associated with impaired cognitive score, we investigated the relationship between RHR and cognitive score in middle-aged, elderly and old Danish subjects from the general population. Methods: Composite cognitive s...... cognitive score (1,049 pairs of 2,049 pairs [51% (95% CI 49–53), p relation to cognitive function in the general population....... and hypertension, RHR was not associated with cognitive function. Furthermore, the intrapair analyses showed that RHR was not associated with cognitive score testing within twin pairs, as measured by the proportion of twin pairs in which the twin with higher RHR also was the twin with the lowest composite...

  9. 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...

  10. Resting and postexercise heart rate variability in professional handball players.

    Science.gov (United States)

    Kayacan, Yildirim; Yildiz, Sedat

    2016-03-01

    The aim of this study was to evaluate heart rate variability (HRV) in professional handball players during rest and following a 5 min mild jogging exercise. For that purpose, electrocardiogram (ECG) of male handball players (N.=12, mean age 25±3.95 years) and sedentary controls (N.=14, mean age 23.5±2.95 years) were recorded for 5 min at rest and just after 5 min of mild jogging. ECGs were recorded and following HRV parameters were calculated: time-domain variables such as heart rate (HR), average normal-to-normal RR intervals, standard deviation of normal-to-normal RR intervals, square root of the mean of the squares of differences between adjacent NN intervals, percentage of differences between adjacent NN intervals that are greater than 50 milliseconds (pNN50), and frequency-domain variables such as very low frequency, low (LF) and high frequency (HF) of the power and LF/HF ratio. Unpaired t-test was used to find out differences among groups while paired t-test was used for comparison of each group for pre- and postjogging HRV. Pearson correlations were carried out to find out the relationships between the parameters. Blood pressures were not different between handball players and sedentary controls but exercise increased systolic blood pressure (Phandball players (Phandball players (Phandball players in response to a mild, short-time (5 min) jogging exercise. However, in sedentary subjects, either the sympathetic regulation of the autonomous nervous system increased or vagal withdrawal occurred.

  11. Heart rate variability in workers chronically exposed to lead.

    Science.gov (United States)

    Gajek, Jacek; Zyśko, Dorota; Chlebda, Ewa

    2004-07-01

    Lead is a strong neurotoxin. The effects of lead on the activity of the autonomic nervous system, assessed by the use of heart rate variability (HRV) analysis, have not yet been established. To assess the effects of occupational chronic lead exposure on the autonomic nervous system activity. The study group consisted of 22 copper foundry workers (mean age 41.8+/-8.7 years) who had elevated parameters of lead overload and were admitted to the hospital for chelate therapy. The control group consisted of 13 age-matched healthy males. Lead concentration was measured with the use of atomic absorption spectrophotometry, and concentration of free protoporphyrins in erythrocytes (FEP) using a fluorometric method. Each patient underwent 24-hour ambulatory ECG monitoring, and standard short-term as well as long-term HRV parameters were obtained. There were no significant differences between patients and controls in HRV parameters. In the control group, HRV parameters correlated with age. In patients, a significant negative correlation between lead concentration and some short-term HRV parameters calculated during the night was found: SDNN (r=-0.48, p<0.05), TP (r=-0.48, p<0.01) and LF (r=-0.48, p<0.01). In patients, a negative correlation between lead concentration and HFnight/HFday index was found (r=-0.47 p<0.01), whereas in controls this correlation was positive (r=0.66 p<0.05). Overall HRV indices are similar in subjects exposed to lead and in healthy controls. A decrease in the physiological elevation of HF values during the night, together with an increase in lead blood concentration and lack of relationship between age and HRV parameters in workers chronically exposed to lead may suggest disturbances of the autonomic system. In subjects not exposed to lead a decrease in heart rate with an increase in FEP concentration was observed.

  12. 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

  13. Brain volumes predict neurodevelopment in adolescents after surgery for congenital heart disease.

    Science.gov (United States)

    von Rhein, Michael; Buchmann, Andreas; Hagmann, Cornelia; Huber, Reto; Klaver, Peter; Knirsch, Walter; Latal, Beatrice

    2014-01-01

    Patients with complex congenital heart disease are at risk for neurodevelopmental impairments. Evidence suggests that brain maturation can be delayed and pre- and postoperative brain injury may occur, and there is limited information on the long-term effect of congenital heart disease on brain development and function in adolescent patients. At a mean age of 13.8 years, 39 adolescent survivors of childhood cardiopulmonary bypass surgery with no structural brain lesions evident through conventional cerebral magnetic resonance imaging and 32 healthy control subjects underwent extensive neurodevelopmental assessment and cerebral magnetic resonance imaging. Cerebral scans were analysed quantitatively using surface-based and voxel-based morphometry. Compared with control subjects, patients had lower total brain (P = 0.003), white matter (P = 0.004) and cortical grey matter (P = 0.005) volumes, whereas cerebrospinal fluid volumes were not different. Regional brain volume reduction ranged from 5.3% (cortical grey matter) to 11% (corpus callosum). Adolescents with cyanotic heart disease showed more brain volume loss than those with acyanotic heart disease, particularly in the white matter, thalami, hippocampi and corpus callosum (all P-values Brain volume reduction correlated significantly with cognitive, motor and executive functions (grey matter: P < 0.05, white matter: P < 0.01). Our findings suggest that there are long-lasting cerebral changes in adolescent survivors of cardiopulmonary bypass surgery for congenital heart disease and that these changes are associated with functional outcome.

  14. The order and volume fill rates in inventory control systems

    DEFF Research Database (Denmark)

    Thorstenson, Anders; Larsen, Christian

    2011-01-01

    This paper differentiates between an order (line) fill rate and a volume fill rate and specifies their performance for different inventory control systems. When the focus is on filling complete customer orders rather than total quantities the order fill rate would be the preferred service level...... measure. The main result shows how the order and volume fill rates are related in magnitude. Earlier results derived for a single-item, single-stage, continuous review inventory system with backordering and constant lead times controlled by a base-stock policy are extended in different directions...

  15. [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

    Cardiovascular diseases are a significant cause of morbidity and mortality in the general population. In this sense, the autonomic imbalance is the cornerstone of the pathophysiology 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 in electronic databases. The considered studies were randomised clinical trials, quasi-experimental studies with non-randomised control group, quasi-experimental studies with analysis of pre- and post- intervention, and crossover studies with randomly assigned training and non-training periods. The standardised mean differences were calculated between pre- and post-intervention in both the control and experimental group. Within-subject analysis of the control group showed no statistical significance in the standardised mean differences of HRV. In the experimental group, the standardised 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 standardised mean difference was negative for LF/HF (-0.747±0.369, P=<.044). On the other hand, only 3 studies entered the comparative meta-analysis. The effect of exercise training was favourable for the experimental group in LF/HF (-2.21±95% CI: -3.83 to -0.60), HF, and LF. The exercise training was effective in increasing HRV and restoring the 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.

  16. Cold-hearted bats: uncoupling of heart rate and metabolism during torpor at sub-zero temperatures.

    Science.gov (United States)

    Currie, Shannon E; Stawski, Clare; Geiser, Fritz

    2018-01-04

    Many hibernating animals thermoregulate during torpor and defend their body temperature ( T b ) near 0°C by an increase in metabolic rate. Above a critical temperature ( T crit ), animals usually thermoconform. We investigated the physiological responses above and below T crit for a small tree-dwelling bat ( Chalinolobus gouldii , ∼14 g) that is often exposed to sub-zero temperatures during winter. Through simultaneous measurement of heart rate ( f H ) and oxygen consumption ( V̇ O 2 ), we show that the relationship between oxygen transport and cardiac function is substantially altered in thermoregulating torpid bats between 1 and -2°C, compared with thermoconforming torpid bats at mild ambient temperatures ( T a 5-20°C). T crit for this species was at a T a of 0.7±0.4°C, with a corresponding T b of 1.8±1.2°C. Below T crit , animals began to thermoregulate, as indicated by a considerable but disproportionate increase in both f H and V̇ O 2 The maximum increase in f H was only 4-fold greater than the average thermoconforming minimum, compared with a 46-fold increase in V̇ O 2 The differential response of f H and V̇ O 2  to low T a was reflected in a 15-fold increase in oxygen delivery per heart beat (cardiac oxygen pulse). During torpor at low T a , thermoregulating bats maintained a relatively slow f H and compensated for increased metabolic demands by significantly increasing stroke volume and tissue oxygen extraction. Our study provides new information on the relationship between metabolism and f H in an unstudied physiological state that may occur frequently in the wild and can be extremely costly for heterothermic animals. © 2018. Published by The Company of Biologists Ltd.

  17. Effects of slow breathing rate on heart rate variability and arterial baroreflex sensitivity in essential hypertension.

    Science.gov (United States)

    Li, Changjun; Chang, Qinghua; Zhang, Jia; Chai, Wenshu

    2018-05-01

    This study is to investigate the effects of slow breathing on heart rate variability (HRV) and arterial baroreflex sensitivity in essential hypertension.We studied 60 patients with essential hypertension and 60 healthy controls. All subjects underwent controlled breathing at 8 and 16 breaths per minute. Electrocardiogram, respiratory, and blood pressure signals were recorded simultaneously. We studied effects of slow breathing on heart rate, blood pressure and respiratory peak, high-frequency (HF) power, low-frequency (LF) power, and LF/HF ratio of HRV with traditional and corrected spectral analysis. Besides, we tested whether slow breathing was capable of modifying baroreflex sensitivity in hypertensive subjects.Slow breathing, compared with 16 breaths per minute, decreased the heart rate and blood pressure (all P hypertensive subjects. Slow breathing increased baroreflex sensitivity in hypertensive subjects (from 59.48 ± 6.39 to 78.93 ± 5.04 ms/mm Hg, P hypertension. Besides, slow breathing increased baroreflex sensitivity in hypertensive subjects. These demonstrate slow breathing is indeed capable of shifting sympatho-vagal balance toward vagal activities and increasing baroreflex sensitivity, suggesting a safe, therapeutic approach for essential hypertension.

  18. Lung and heart dose volume analyses with CT simulator in radiation treatment of breast cancer

    International Nuclear Information System (INIS)

    Das, Indra J.; Cheng, Elizabeth C.; Freedman, Gary; Fowble, Barbara

    1998-01-01

    Purpose: Radiation pneumonitis and cardiac effects are directly related to the irradiated lung and heart volumes in the treatment fields. The central lung distance (CLD) from a tangential breast radiograph is shown to be a significant indicator of ipsilateral irradiated lung volume. Retrospective analysis of the pattern of dose volume of lung and heart with actual volume data from a CT simulator in the treatment of breast cancer is presented with respect to CLD. Methods and Materials: The heart and lung volumes in the tangential treatment fields were analyzed in 108 consecutive cases (52 left and 56 right breast) referred for CT simulation. All patients in this study were immobilized and placed on an inclined breast board in actual treatment setup. Both arms were stretched over head to avoid collision with the scanner aperture. Radiopaque marks were placed on the medial and lateral borders of the tangential fields. All patients were scanned in spiral mode with slice width and thickness of 3 mm each, respectively. The lung and heart structures as well as irradiated areas were delineated on each slice and respective volumes were accurately measured. The treatment beam parameters were recorded and the digitally reconstructed radiographs (DRRs) were generated for the measurement of the CLD and analysis. Results: Using CT data the mean volume and standard deviation of left and right lungs were 1307.7 ± 297.7 cm 3 and 1529.6 ± 298.5 cm 3 , respectively. The magnitude of irradiated volume in left and right lung is nearly equal for the same CLD that produces different percent irradiated volumes (PIV). The left and right PIV lungs are 8.3 ± 4.7% and 6.6 ± 3.7%, respectively. The PIV data have shown to correlate with CLD with second- and third-degree polynomials; however, in this study a simple straight line regression is used to provide better confidence than the higher order polynomials. The regression lines for the left and right breasts are very different based on

  19. The Performance of Short-Term Heart Rate Variability in the Detection of Congestive Heart Failure

    Directory of Open Access Journals (Sweden)

    Fausto Lucena

    2016-01-01

    Full Text Available Congestive heart failure (CHF is a cardiac disease associated with the decreasing capacity of the cardiac output. It has been shown that the CHF is the main cause of the cardiac death around the world. Some works proposed to discriminate CHF subjects from healthy subjects using either electrocardiogram (ECG or heart rate variability (HRV from long-term recordings. In this work, we propose an alternative framework to discriminate CHF from healthy subjects by using HRV short-term intervals based on 256 RR continuous samples. Our framework uses a matching pursuit algorithm based on Gabor functions. From the selected Gabor functions, we derived a set of features that are inputted into a hybrid framework which uses a genetic algorithm and k-nearest neighbour classifier to select a subset of features that has the best classification performance. The performance of the framework is analyzed using both Fantasia and CHF database from Physionet archives which are, respectively, composed of 40 healthy volunteers and 29 subjects. From a set of nonstandard 16 features, the proposed framework reaches an overall accuracy of 100% with five features. Our results suggest that the application of hybrid frameworks whose classifier algorithms are based on genetic algorithms has outperformed well-known classifier methods.

  20. Heart rate variability enhances the prognostic value of established parameters in patients with congestive heart failure.

    Science.gov (United States)

    Krüger, C; Lahm, T; Zugck, C; Kell, R; Schellberg, D; Schweizer, M W F; Kübler, W; Haass, M

    2002-12-01

    This prospective study evaluated whether heart rate variability (HRV) assessed from Holter ECG has prognostic value in addition to established parameters in patients with congestive heart failure (CHF). The study included 222 patients with CHF due to dilated or ischemic cardiomyopathy (left ventricular ejection fraction LVEF 21+/-1%; mean+/-SEM). During a mean follow-up of 15+/-1 months, 38 (17%) patients died and 45 (20%) were hospitalized due to worsening of CHF. The HRV parameter SDNN (standard deviation of all intervals between normal beats) was significantly lower in non-surviving or hospitalized than in event-free patients (118+/-6 vs 142+/-5 ms), as were LVEF (18+/-1 vs 23+/-1%), and peak oxygen uptake during exercise (peak VO(2)) (12.8+/-0.5 vs 15.6+/-0.5 ml/min/kg). While each of these parameters was a risk predictor in univariate analysis, multivariate analysis revealed that HRV provides both independent and additional prognostic information with respect to the risk 'cardiac mortality or deterioration of CHF'. It is concluded that the determination of HRV enhances the prognostic power given by the most widely used parameters LVEF and peak VO(2) in the prediction of mortality or deterioration of CHF and thus enables to improve risk stratification.

  1. 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.

  2. False Heart Rate Feedback and the Perception of Heart Symptoms in Patients with Congenital Heart Disease and Anxiety

    NARCIS (Netherlands)

    Karsdorp, Petra A.; Kindt, Merel; Rietveld, Simon; Everaerd, Walter; Mulder, Barbara J. M.

    2009-01-01

    Background Little is known about the mechanisms explaining an increased perception of heart symptoms in congenital heart disease (ConHD). In the present study, it was suggested that a combination of high trait anxiety and disease history increases the perception of heart symptoms. Purpose It was

  3. False heart rate feedback and the perception of heart symptoms in patients with congenital heart disease and anxiety

    NARCIS (Netherlands)

    Karsdorp, P.A.; Kindt, M.; Rietveld, S.; Everaerd, W.; Mulder, B.J.M.

    2009-01-01

    Background: Little is known about the mechanisms explaining an increased perception of heart symptoms in congenital heart disease (ConHD). In the present study, it was suggested that a combination of high trait anxiety and disease history increases the perception of heart symptoms. Purpose: It was

  4. Heart Rate Variability in Patients with Chronic Obstructive Pulmonary Disease Treated by Noninvasive Mechanic Ventilation

    Directory of Open Access Journals (Sweden)

    Zekeriya Küçükdurmaz

    2011-08-01

    Full Text Available Aims: This study aimed to investigate heart rate variability (HRV of patients with severe COPD who are treated by noninvasive mechanic ventilation (NIMV.Patients and Method: Twenty-seven patient (58±8 years, 9 F with severe COPD treated by nocturnal NIMV at home and 23 sex and age matched volunteers (56±8 years, 11 F who has not dyspnea as a control group recruited in the study. Subjects underwent spirometry, blood gas analysis, transthoracic echocardiography, 24 hours ambulatory ECG analysis. Time domain HRV analysis performed from ambulatory ECG records. Results: 52% of patients at NYHA functional class II, 36% at class III, and 12% at class IV when they have been treated by NIMV. Groups were similar for age and sex (p>0.05 for both. Heart rates of patients were higher significantly than controls’ (p0.05. But, systolic pulmonary pressures were higher of COPD group (p<0.01. 24 hours heart rate was higher, and standard deviation of normal R-R intervals (SDNN 24 hours, SDNN night, SDNN day, SDNN index (SDNNI and standard deviation of mean R-R intervals (SDANNI values were lower in COPD group significantly. SDNN was inversely correlated with duration of daily NIMV usage, intensive care unit administration and entubation rate and PaCO2. SDNNI was inversely correlated with functional class, duration of daily NIMV usage, intensive care unit administration rate and PaCO2. Else, SDNNI was correlated with predicted forced vital capacity % (FVC% and predicted forced expiratory volume at 1 second % (FEV1%.Conclusion: Time domain HRV decreases in patients with severe COPD. Decrease is correlated with severity of disease, and it presents in despite of the chronic nocturnal NIMV application. These patients have high risk for cardiovascular morbidity and mortality and should be monitored and manegement for cardiovascular events.

  5. Effects of smoking on heart rate at rest and during exercise, and on heart rate recovery, in young adults.

    Science.gov (United States)

    Papathanasiou, George; Georgakopoulos, Dimitris; Papageorgiou, Effie; Zerva, Efthimia; Michalis, Lampros; Kalfakakou, Vasiliki; Evangelou, Angelos

    2013-01-01

    There is an established link between smoking, abnormal heart rate (HR) values, and impaired cardiovascular health in middle-aged or older populations. The purpose of this study was to examine the effects of smoking on resting HR and on HR responses during and after exercise in young adults. A sample of 298 young adults (159 men), aged 20-29 years old, were selected from a large population of health-science students based on health status, body mass index, physical activity, and smoking habit. All subjects underwent a maximal Bruce treadmill test and their HR was recorded during, at peak, and after termination of exercise. Smokers had significantly higher resting HR values than non-smokers. Both female and male smokers showed a significantly slower HR increase during exercise. Female smokers failed to reach their age-predicted maximum HR by 6.0 bpm and males by 3.6 bpm. The actual maximum HR achieved (HRmax) was significantly lower for both female smokers (191.0 bpm vs.198.0 bpm) and male smokers (193.2 bpm vs.199.3 bpm), compared to non-smokers. Heart rate reserve was also significantly lower in female (114.6 bpm vs. 128.1 bpm) and male smokers (120.4 bpm vs. 133.0 bpm). During recovery, the HR decline was significantly attenuated, but only in female smokers. Females had a higher resting HR and showed a higher HR response during sub-maximal exercise compared to males. Smoking was found to affect young smokers' HR, increasing HR at rest, slowing HR increase during exercise and impairing their ability to reach the age-predicted HRmax. In addition, smoking was associated with an attenuated HR decline during recovery, but only in females.

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

    Directory of Open Access Journals (Sweden)

    Ali Metin Esen

    2010-04-01

    Full Text Available Summary: Atrial fibrillation (AF is known to be one of the most important complications of mitral stenosis (MS. It has been reported that autonomic nervous system (ANS had an effect on AF development, heart rate variability (HRV and heart rate recovery (HRR were under the control of ANS, and their disorders were present in MS. We studied the effect of Valsartan on HRV and HRT, and thus its effect on ANS. Methods: Eleven patients (39±8 years, 10 females with mild to moderate MS were included in the study. Sixteen volunteers (38±8 years, 14 females matched for age and sex were selected for control group. All subjects underwent transthoracic echocardiography (TTE, symptom-limited treadmill test and 24 hour Holter monitorization.The patients were administered 160 mg of Valsartan daily for 14 weeks. TTE, treadmill test and Holter monitorization were repeated at the end of treatment period. In Holter monitorization, the time and frequency domain analysis of HRV and in exercise test, HRR at first and third minutes (HRR1 and HRR3 were examined. Results: Before Valsartan treatment, no significant difference was found in HRR and HRV parameters between the two groups. Systolic and diastolic blood pressure, and also HRR1values were significantly decreased after treatment of Valsartan (117±6 vs. 107±4 mmHg p<0.002, 76±6 vs. 69±9 mmHg p<0.044, 44±14 vs. 33±12 p< 0.014, respectively, while the exercise time was significantly increased (786±114 vs. 846±95 sn p< 0.044. In Holter analysis neither time nor frequency domain of HRV parameters showed a meaningful change. Conclusion: In moderate MS, treatment with Valsartan improved the effort capacity, while autonomic function parameters have been defined on the base of HRV and HRR were not significantly different.

  7. Efectos de la ingesta ad libitum de bebidas hidratantes sobre el peso corporal, la frecuencia cardíaca y el volumen plasmático durante una actividad física de alta intensidad y larga duración -Informe preliminar- Body weight, the heart rate, and the plasma volume during a high-intesity, long-duration run

    Directory of Open Access Journals (Sweden)

    Rubiela Flórez Manrique

    2004-02-01

    , no ingieren la cantidad adecuada de líquidos para obtener los beneficios atribuidos a la hidratación. Objetive: to determine the amount of ad libitum intake of three rehydrating beverages of different osmolalities, and to establish their effects on the percentage of body weight loss, the increase of heart rate and the reduction of plasma volume, in nine subjects with aerobic training, during a highintensity,long-duration run. Methodology : the experiment was carried out on a treadmill with 1% of inclination that was kept constant throughout the procedure; it started with 9 minutes of warm-up at a speed equivalent to 59% of the reserve heart rate; then, 88 minutes of running divided in three intervals (29, 29, and 30 minutes at 80% of the reserve heart rate; finally, 90 minutes of recovery in three intervals of 30 minutes each. During the “dehydrated treatment” no fluid replacement was done; during the “Hydrating treatments” (H-I, H-II, H-III equivalent volumes were drunk of the aforementioned rehydrating beverages. Results: during the exercise period the fluid loss was 1.440 ml/h. In each one of the treatments there was a loss of body weight (p<0.001, an increase of heart rate (<0.05 and, except for HII and H-III, a reduction of plasma volume (p<0.05. There were no differences between the treatments in these three parameters. Conclusions: ad libitum intake was less than the amount internationally recommended; probably that explains that the effects of osmolality of the rehydrating beverages on the analyzed parameters could not be determined. These findings ought to motivate a review of the hydrating practices of our athletes because, seemingly, they are not ingesting an adequate amount of fluids to obtain the benefits attributed to hydration.

  8. Improvement of energy expenditure prediction from heart rate during running

    International Nuclear Information System (INIS)

    Charlot, Keyne; Borne, Rachel; Richalet, Jean-Paul; Chapelot, Didier; Pichon, Aurélien; Cornolo, Jérémy; Brugniaux, Julien Vincent

    2014-01-01

    We aimed to develop new equations that predict exercise-induced energy expenditure (EE) more accurately than previous ones during running by including new parameters as fitness level, body composition and/or running intensity in addition to heart rate (HR). Original equations predicting EE were created from data obtained during three running intensities (25%, 50% and 70% of HR reserve) performed by 50 subjects. Five equations were conserved according to their accuracy assessed from error rates, interchangeability and correlations analyses: one containing only basic parameters, two containing VO 2max  or speed at VO 2max  and two including running speed with or without HR. Equations accuracy was further tested in an independent sample during a 40 min validation test at 50% of HR reserve. It appeared that: (1) the new basic equation was more accurate than pre-existing equations (R 2  0.809 versus. 0,737 respectively); (2) the prediction of EE was more accurate with the addition of VO 2max  (R 2  = 0.879); and (3) the equations containing running speed were the most accurate and were considered to have good agreement with indirect calorimetry. In conclusion, EE estimation during running might be significantly improved by including running speed in the predictive models, a parameter readily available with treadmill or GPS. (paper)

  9. Heart rate variability biofeedback improves cardiorespiratory resting function during sleep.

    Science.gov (United States)

    Sakakibara, Masahito; Hayano, Junichiro; Oikawa, Leo O; Katsamanis, Maria; Lehrer, Paul

    2013-12-01

    The present study was designed to examine the effect of heart rate variability (HRV) biofeedback on the cardiorespiratory resting function during sleep in daily life. Forty-five healthy young adults were randomly assigned to one of three groups: HRV biofeedback, Autogenic Training(AT), and no-treatment control. Participants in the HRV biofeedback were instructed to use a handheld HRV biofeedback device before their habitual bedtime, those in the AT were asked to listen to an audiotaped instruction before bedtime,and those in the control were asked to engage in their habitual activity before bedtime. Pulse wave signal during sleep at their own residences was measured continuously with a wrist watch-type transdermal photoelectric sensor for three time points. Baseline data were collected on the first night of measurements, followed by two successive nights for HRV biofeedback, AT, or control. Cardiorespiratory resting function was assessed quantitatively as the amplitude of high frequency(HF) component of pulse rate variability, a surrogate measure of respiratory sinus arrhythmia. HF component increased during sleep in the HRV biofeedback group,although it remained unchanged in the AT and control groups. These results suggest that HRV biofeedback before sleep may improve cardiorespiratory resting function during sleep.

  10. Heart rate modulation in stable coronary artery disease without clinical heart failure: What we have already learned from SIGNIFY?

    Directory of Open Access Journals (Sweden)

    Gian Piero Perna

    2016-12-01

    In conclusion, heart rate is a marker of risk but is not a risk factor and/or a target of therapy in patients with stable coronary artery disease and preserved ventricular systolic function. Standard doses of ivabradine are indicated for treatment of angina as an alternative or in addition to beta-blockers, but should not be administered in association with CYP3A4 inhibitors or heart rate-lowering calcium-channel blockers.

  11. Short- and long-term variations in non-linear dynamics of heart rate variability

    DEFF Research Database (Denmark)

    Kanters, J K; Højgaard, M V; Agner, E

    1996-01-01

    OBJECTIVES: The purpose of the study was to investigate the short- and long-term variations in the non-linear dynamics of heart rate variability, and to determine the relationships between conventional time and frequency domain methods and the newer non-linear methods of characterizing heart rate...... rate and describes mainly linear correlations. Non-linear predictability is correlated with heart rate variability measured as the standard deviation of the R-R intervals and the respiratory activity expressed as power of the high-frequency band. The dynamics of heart rate variability changes suddenly...

  12. Functional distribution of coronary vascular volume in beating goat hearts

    NARCIS (Netherlands)

    van der Ploeg, C. P.; Dankelman, J.; Spaan, J. A.

    1993-01-01

    With use of hemoglobin-bound O2 as an endogenous tracer, intramyocardial blood volume distribution between vessels involved in O2 exchange and more distal vessels was estimated. In nine anesthetized open-chest goats, the left main coronary artery was cannulated and perfused at a constant flow.

  13. Evaluation on the influence of electrocardiograph modulated milliampere on image quality and exposure dosage of volume CT heart scan

    International Nuclear Information System (INIS)

    Zhang Sen; Du Xiangke; Li Jianyin

    2006-01-01

    Objective: To find out whether the use of ECG modulated current (mA) will influence image quality and to decide whether the electrocardiograph (ECG) modulated mA will effectively reduce the exposure dosage. Methods: The cardiac pulsating phantom was set at three speed levels, i.e. high, medium, and low speed so as to simulate different heart rates. The phantom was scanned with ECG modulated mA turned on and off, and the exposure dosage of each scan sequence was documented. The images were reconstructed with reconstruction algorithm that matched the different levels of heart rate. CT values and their corresponding standard deviations at uniform areas on the images and the variation of the CT values at different locations were measured. The results from the two groups with and without ECG modulated mA were analyzed. Results: Under the same level of heart rate, the exposure dosage was remarkably reduced when the ECG modulated mA was on than when it was off. Statistical analysis showed no significant difference (P>0.05) between the images from the two groups. Conclusion: When scanning the heart with volume CT (VCT), the application of ECG modulated mA can effectively reduce the exposure dosage without sacrificing the image quality. (authors)

  14. 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 inter......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...

  15. Reliability of heart rate mobile apps in young healthy adults: exploratory study and research directions

    Directory of Open Access Journals (Sweden)

    Maria Parpinel

    2017-06-01

    Full Text Available Background: Recently, a number of smartphone apps appeared that allow for heart rate measurements basing on the photoplethysmography principle. In fact, almost every smartphone now has a camera with flash that could be used for that. Some studies appeared on the reliability of some of those apps, with heterogeneous results. Objectives: The present study aims at adding up evidence in particular during physical activity, by comparing 3 apps on two different platforms (IOs and Android, on a broad range of heart rates. As gold standard, heart rate has been measured with a traditional heart rate monitor. Results: The results suggest that heart rate apps might be used for measuring heart rate for fitness aims for many individuals, but further research is needed to i analyse influence of smartphone features; ii identify personal factors hindering measurements, and iii verify reliability on different measurement sites.

  16. Approximate entropy and point correlation dimension of heart rate variability in healthy subjects

    DEFF Research Database (Denmark)

    Storella, R J; Wood, H W; Mills, K M

    1999-01-01

    The contribution of nonlinear dynamics to heart rate variability in healthy humans was examined using surrogate data analysis. Several measures of heart rate variability were used and compared. Heart rates were recorded for three hours and original data sets of 8192 R-R intervals created. For each...... original data set (n = 34), three surrogate data sets were made by shuffling the order of the R-R intervals while retaining their linear correlations. The difference in heart rate variability between the original and surrogate data sets reflects the amount of nonlinear structure in the original data set....... Heart rate variability was analyzed by two different nonlinear methods, point correlation dimension and approximate entropy. Nonlinearity, though under 10 percent, could be detected with both types of heart rate variability measures. More importantly, not only were the correlations between...

  17. Electrocardiogram application based on heart rate variability ontology and fuzzy markup language

    NARCIS (Netherlands)

    Wang, M.-H.; Lee, C.-S.; Acampora, G.; Loia, V.; Gacek, A.; Pedrycz, W.

    2011-01-01

    The electrocardiogram (ECG) signal is adopted extensively as a low-cost diagnostic procedure to provide information concerning the healthy status of the heart. Heart rate variability (HRV) is a physiological phenomenon where the time interval between heart beats varies. It is measured by the

  18. Heart rate variability in sleep-related migraine without aura.

    Science.gov (United States)

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

    2013-07-15

    This is an observational study aimed to investigate the activity of autonomic nervous system during sleep in patients with sleep-related migraine. Eight consecutive migraineurs without aura were enrolled (6 women and 2 men), aged 30 to 62 years (mean 48.1 ± 9.3 years). Inclusion criteria were: high frequency of attacks (> 5 per month) and occurrence of more than 75% of the attacks during sleep causing an awakening. Patients were compared with a control group of 55 healthy subjects (23 men and 32 women, mean age 54.2 ± 13.0 years), and with a further control group of 8 age- and gender-matched healthy controls. Patient and controls underwent polysomnography and heart rate variability analysis. A significant reduction of the LF/HF ratio during N2 and N3 sleep stages was observed in migraineurs compared with controls. No differences in sleep macrostructure were observed; cyclic alternating pattern (CAP) time and CAP rate were lower in migraineurs than in controls. These findings indicate a peculiar modification of the autonomic balance during sleep in sleep-related migraine. The reduction of LF/HF ratio in NREM sleep was observed in controls, but it was quantitatively much more evident in migraineurs. Changes in LF/HF could be consequent to an autonomic unbalance which could manifest selectively (or alternatively become more evident) during sleep. These findings, together with the reduction in CAP rate, could be an expression of reduced arousability during sleep in patients with sleep-related migraine. The simultaneous involvement of the autonomic, arousal, and pain systems might suggest involvement of the hypothalamic pathways.

  19. [Design of Oxygen Saturation, Heart Rate, Respiration Rate Detection System Based on Smartphone of Android Operating System].

    Science.gov (United States)

    Zhu, Mingshan; Zeng, Bixin

    2015-03-01

    In this paper, we designed an oxygen saturation, heart rate, respiration rate monitoring system based on smartphone of android operating system, physiological signal acquired by MSP430 microcontroller and transmitted by Bluetooth module.

  20. Navigator channel adaptation to reconstruct three dimensional heart volumes from two dimensional radiotherapy planning data

    International Nuclear Information System (INIS)

    Ng, Angela; Nguyen, Thao-Nguyen; Moseley, Joanne L; Hodgson, David C; Sharpe, Michael B; Brock, Kristy K

    2012-01-01

    Biologically-based models that utilize 3D radiation dosimetry data to estimate the risk of late cardiac effects could have significant utility for planning radiotherapy in young patients. A major challenge arises from having only 2D treatment planning data for patients with long-term follow-up. In this study, we evaluate the accuracy of an advanced deformable image registration (DIR) and navigator channels (NC) adaptation technique to reconstruct 3D heart volumes from 2D radiotherapy planning images for Hodgkin's Lymphoma (HL) patients. Planning CT images were obtained for 50 HL patients who underwent mediastinal radiotherapy. Twelve image sets (6 male, 6 female) were used to construct a male and a female population heart model, which was registered to 23 HL 'Reference' patients' CT images using a DIR algorithm, MORFEUS. This generated a series of population-to-Reference patient specific 3D deformation maps. The technique was independently tested on 15 additional 'Test' patients by reconstructing their 3D heart volumes using 2D digitally reconstructed radiographs (DRR). The technique involved: 1) identifying a matching Reference patient for each Test patient using thorax measurements, 2) placement of six NCs on matching Reference and Test patients' DRRs to capture differences in significant heart curvatures, 3) adapting the population-to-Reference patient-specific deformation maps to generate population-to-Test patient-specific deformation maps using linear and bilinear interpolation methods, 4) applying population-to-Test patient specific deformation to the population model to reconstruct Test-patient specific 3D heart models. The percentage volume overlap between the NC-adapted reconstruction and actual Test patient's true heart volume was calculated using the Dice coefficient. The average Dice coefficient expressed as a percentage between the NC-adapted and actual Test model was 89.4 ± 2.8%. The modified NC adaptation

  1. Glutamate transporter type 3 knockout leads to decreased heart rate possibly via parasympathetic mechanism

    OpenAIRE

    Deng, Jiao; Li, Jiejie; Li, Liaoliao; Feng, Chenzhuo; Xiong, Lize; Zuo, Zhiyi

    2013-01-01

    Parasympathetic tone is a dominant neural regulator for basal heart rate. Glutamate transporters (EAAT) via their glutamate uptake functions regulate glutamate neurotransmission in the central nervous system. We showed that EAAT type 3 (EAAT3) knockout mice had a slower heart rate than wild-type mice when they were anesthetized. We design this study to determine whether non-anesthetized EAAT3 knockout mice have a slower heart rate and, if so, what may be the mechanism for this effect. Young a...

  2. Estimating Energy Expenditure from Heart Rate in Older Adults: A Case for Calibration

    OpenAIRE

    Schrack, Jennifer A.; Zipunnikov, Vadim; Goldsmith, Jeff; Bandeen-Roche, Karen; Crainiceanu, Ciprian M.; Ferrucci, Luigi

    2014-01-01

    Background Accurate measurement of free-living energy expenditure is vital to understanding changes in energy metabolism with aging. The efficacy of heart rate as a surrogate for energy expenditure is rooted in the assumption of a linear function between heart rate and energy expenditure, but its validity and reliability in older adults remains unclear. Objective To assess the validity and reliability of the linear function between heart rate and energy expenditure in older adults using diffe...

  3. Abnormal heart rate recovery and deficient chronotropic response after submaximal exercise in young Marfan syndrome patients.

    Science.gov (United States)

    Peres, Paulo; Carvalho, Antônio C; Perez, Ana Beatriz A; Medeiros, Wladimir M

    2016-10-01

    Marfan syndrome patients present important cardiac structural changes, ventricular dysfunction, and electrocardiographic changes. An abnormal heart rate response during or after exercise is an independent predictor of mortality and autonomic dysfunction. The aim of the present study was to compare heart rate recovery and chronotropic response obtained by cardiac reserve in patients with Marfan syndrome subjected to submaximal exercise. A total of 12 patients on β-blocker therapy and 13 off β-blocker therapy were compared with 12 healthy controls. They were subjected to submaximal exercise with lactate measurements. The heart rate recovery was obtained in the first minute of recovery and corrected for cardiac reserve and peak lactate concentration. Peak heart rate (141±16 versus 155±17 versus 174±8 bpm; p=0.001), heart rate reserve (58.7±9.4 versus 67.6±14.3 versus 82.6±4.8 bpm; p=0.001), heart rate recovery (22±6 versus 22±8 versus 34±9 bpm; p=0.001), and heart rate recovery/lactate (3±1 versus 3±1 versus 5±1 bpm/mmol/L; p=0.003) were different between Marfan groups and controls, respectively. All the patients with Marfan syndrome had heart rate recovery values below the mean observed in the control group. The absolute values of heart rate recovery were strongly correlated with the heart rate reserve (r=0.76; p=0.001). Marfan syndrome patients have reduced heart rate recovery and chronotropic deficit after submaximal exercise, and the chronotropic deficit is a strong determinant of heart rate recovery. These changes are suggestive of autonomic dysfunction.

  4. The relationship between heart rate and rate of oxygen consumption in Galapagos marine iguanas (Amblyrhynchus cristatus) at two different temperatures.

    Science.gov (United States)

    Butler, Patrick J; Frappell, Peter B; Wang, Tobias; Wikelski, Martin

    2002-07-01

    To enable the use of heart rate (fH) for estimating field metabolic rate (FMR) in free-ranging Galapagos marine iguanas Amblyrhynchus cristatus, we determined the relationships between fH and mass-specific rate of oxygen consumption (sVO2) in seven iguanas before and during exercise on a treadmill and during the post-exercise period. The experiments were conducted at 27 and 35 degrees C, which are the temperatures that represent the lowest and highest average body temperatures of these animals in the field during summer. There were linear and significant relationships between fH and sVO2 at both temperatures (r(2)=0.86 and 0.91 at 27 degrees C and 36 degrees C, respectively). The slopes of the two regression lines did not differ, but there were significant differences in their intercepts. Thus, while heart rate can be used to predict FMR, the effects of temperature on the intercept of the regression must be taken into account when converting fH to sVO2. On the basis of our data, this can be achieved by applying the following formula: sVO2=0.0113fH-0.2983Q(10)((T(b)-27)/10). The increase in sVO2 with elevated body temperature results from an increase in fH, with no significant change in mass-specific oxygen pulse (sO(2) pulse; cardiac stroke volume times the difference in oxygen content between arterial and mixed venous blood). However, during exercise at both temperatures, increases in fH are insufficient to provide all of the additional O(2) required and there are also significant increases in the sO(2) pulses. This creates the situation whereby the same fH at the two temperatures can represent different values of sVO2.

  5. Relationship between heart rate and quiescent interval of the cardiac cycle in children using MRI

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Wei [Texas Children' s Hospital, E. B. Singleton Department of Pediatric Radiology, Houston, TX (United States); Bogale, Saivivek [Baylor University Medical Center, Department of Radiology, Dallas, TX (United States); Golriz, Farahnaz [Baylor College of Medicine, Department of Radiology, Houston, TX (United States); Krishnamurthy, Rajesh [Nationwide Children' s Hospital, Department of Diagnostic Radiology, Columbus, OH (United States)

    2017-11-15

    Imaging the heart in children comes with the challenge of constant cardiac motion. A prospective electrocardiography-triggered CT scan allows for scanning during a predetermined phase of the cardiac cycle with least motion. This technique requires knowing the optimal quiescent intervals of cardiac cycles in a pediatric population. To evaluate high-temporal-resolution cine MRI of the heart in children to determine the relationship of heart rate to the optimal quiescent interval within the cardiac cycle. We included a total of 225 consecutive patients ages 0-18 years who had high-temporal-resolution cine steady-state free-precession sequence performed as part of a magnetic resonance imaging (MRI) or magnetic resonance angiography study of the heart. We determined the location and duration of the quiescent interval in systole and diastole for heart rates ranging 40-178 beats per minute (bpm). We performed the Wilcoxon signed rank test to compare the duration of quiescent interval in systole and diastole for each heart rate group. The duration of the quiescent interval at heart rates <80 bpm and >90 bpm was significantly longer in diastole and systole, respectively (P<.0001 for all ranges, except for 90-99 bpm [P=.02]). For heart rates 80-89 bpm, diastolic interval was longer than systolic interval, but the difference was not statistically significant (P=.06). We created a chart depicting optimal quiescent intervals across a range of heart rates that could be applied for prospective electrocardiography-triggered CT imaging of the heart. The optimal quiescent interval at heart rates <80 bpm is in diastole and at heart rates ≥90 bpm is in systole. The period of quiescence at heart rates 80-89 bpm is uniformly short in systole and diastole. (orig.)

  6. Effects of Exercise Training on Heart Rate Variability in Chagas Heart Disease

    Directory of Open Access Journals (Sweden)

    Bruno Ramos Nascimento

    2014-09-01

    Full Text Available Background: Heart rate variability (HRV is a marker of autonomic dysfunction severity. The effects of physical training on HRV indexes in Chagas heart disease (CHD are not well established. Objective: To evaluate the changes in HRV indexes in response to physical training in CHD. Methods: Patients with CHD and left ventricular (LV dysfunction, physically inactive, were randomized either to the intervention (IG, N = 18 or control group (CG, N = 19. The IG participated in a 12-week exercise program consisting of 3 sessions/week. Results: Mean age was 49.5 ± 8 years, 59% males, mean LVEF was 36.3 ± 7.8%. Baseline HRV indexes were similar between groups. From baseline to follow-up, total power (TP: 1653 (IQ 625 - 3418 to 2794 (1617 - 4452 ms, p = 0.02 and very low frequency power: 586 (290 - 1565 to 815 (610 - 1425 ms, p = 0.047 increased in the IG, but not in the CG. The delta (post - pre HRV indexes were similar: SDNN 11.5 ± 30.0 vs. 3.7 ± 25.1 ms. p = 0.10; rMSSD 2 (6 - 17 vs. 1 (21 - 9 ms. p = 0.43; TP 943 (731 - 3130 vs. 1780 (921 - 2743 Hz. p = 0.46; low frequency power (LFP 1.0 (150 - 197 vs. 60 (111 - 146 Hz. p = 0.85; except for high frequency power, which tended to increase in the IG: 42 (133 - 92 vs. 79 (61 - 328 Hz. p = 0.08. Conclusion: In the studied population, the variation of HRV indexes was similar between the active and inactive groups. Clinical improvement with physical activity seems to be independent from autonomic dysfunction markers in CHD.

  7. 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

    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 di......) and fetal muscle samples by including our novel variants.Our findings advance the knowledge of the genetic architecture of heart rate, and indicate new candidate genes for follow-up functional studies....

  8. Correlation of heart rate and radionuclide index of left ventricular contraction and relaxation

    International Nuclear Information System (INIS)

    Adachi, Haruhiko; Sugihara, Hiroki; Nakagawa, Hiroaki; Inagaki, Suetsugu; Kubota, Yasushi; Nakagawa, Masao

    1990-01-01

    Since the cardiac function indices derived from radionuclide ventriculography (RNV) are considered to depend on the heart rate, we studied the relationship between systolic or diastolic indices and heart rates in patients with normal RNV and devised a method of correcting these indices according to the heart rate. For the systolic indices, the heart rate showed significant correlation with ET (r=-0.640), PER (r=0.791) and TPE (r=-0.401) but not with EF, 1/3 EF, MNSER or 1/3 MNSER. For the diastolic indices, the heart rate correlated well with FT (r=-0.938), RFT (r=-0.736), SFT (r=-0.803), 1/3 FF (r=-0.758), PFR (r=0.759), 1/3 PFR (r=0.742) and TPF (r=-0.389) but not with AFT, 1/3 MNDFR or AFF. These results indicate that many systolic and diastolic indices derived from RNV are affected by the heart rate, So when cardiac function is evaluated with the use of radionuclide indices, those which are independent of the heart rate should be used, or they should be corrected for the heart rate. As a method of correction, we proposed a rotating method obtained by manipulation of the regression equation of heart rates and indices. This new method is certain and easier to use when the correcting equations are set into a computer program. (author)

  9. Sleep Apnoea Detection in Single Channel ECGs by Analyzing Heart Rate Dynamics

    National Research Council Canada - National Science Library

    Zywietz, C

    2001-01-01

    .... Our analysis is based on spectral components of heart rate variability. Frequency analysis was performed using Fourier and wavelet transformation with appropriate application of the Hilbert transform...

  10. Digital Heart-Rate Variability Parameter Monitoring and Assessment ASIC.

    Science.gov (United States)

    Massagram, W; Hafner, N; Mingqi Chen; Macchiarulo, L; Lubecke, V M; Boric-Lubecke, O

    2010-02-01

    This paper describes experimental results for an application-specific integrated circuit (ASIC), designed for digital heart rate variability (HRV) parameter monitoring and assessment. This ASIC chip measures beat-to-beat (RR) intervals and stores HRV parameters into its internal memory in real time. A wide range of short-term and long-term ECG signals obtained from Physionet was used for testing. The system detects R peaks with millisecond accuracy, and stores up to 2 min of continuous RR interval data and up to 4 min of RR interval histogram. The prototype chip was fabricated in a 0.5 ¿m complementary metal-oxide semiconductor technology on a 3×3 mm(2) die area, with a measured dynamic power consumption of 10 ¿W and measured leakage current of 2.62 nA. The HRV monitoring system including this HRV ASIC, an analog-to-digital converter, and a low complexity microcontroller was estimated to consume 32.5 ¿V, which is seven times lower power than a stand-alone microcontroller performing the same functions. Compact size, low cost, and low power consumption make this chip suitable for a miniaturized portable HRV monitoring system.

  11. Low heart rate variability in patients with clinical burnout.

    Science.gov (United States)

    Lennartsson, Anna-Karin; Jonsdottir, Ingibjörg; Sjörs, Anna

    2016-12-01

    Several studies have shown that acute psychosocial stress and chronic psychosocial stress reduce heart rate variability (HRV). It is likely that individuals suffering from burnout have reduced HRV, as a consequence of the long-term stress exposure. This study investigated HRV in 54 patients with clinical burnout (40 women and 14 men) and in 55 individuals reporting low burnout scores (healthy; 24 women and 31 men) and 52 individuals reporting high burnout scores (non-clinical burnout; 33 women and 19 men). The participants underwent a 300s ECG recording in the supine position. Standard deviation of normal R-R intervals (SDNN) and the root mean square of successive normal interval differences (RMSSD) were derived from time domain HRV analysis. Frequency domain HRV measures; total power (TP), low frequency power (LF), high frequency power (HF), and LF/HF ratio were calculated. All HRV measures, except LF/HF ratio, were lower in the clinical burnout patients compared to both the non-clinical burnout group and the healthy group. The difference was larger between the patients and the healthy group than between the patients and the non-clinical burnout group. HRV did not differ significantly between the non-clinical burnout group and the healthy group. Low HRV in burnout patients may constitute one of the links to associated adverse health, since low HRV reflects low parasympathetic activity - and accordingly low anabolic/regenerative activity. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Determining cardiac vagal threshold from short term heart rate complexity

    Directory of Open Access Journals (Sweden)

    Hamdan Rami Abou

    2016-09-01

    Full Text Available Evaluating individual aerobic exercise capacity is fundamental in sports and exercise medicine but associated with organizational and instrumental effort. Here, we extract an index related to common performance markers, the aerobic and anaerobic thresholds enabling the estimation of exercise capacity from a conventional sports watch supporting beatwise heart rate tracking. Therefore, cardiac vagal threshold (CVT was determined in 19 male subjects performing an incremental maximum exercise test. CVT varied around the anaerobic threshold AnT with mean deviation of 7.9 ± 17.7 W. A high correspondence of the two thresholds was indicated by Bland-Altman plots with limits of agreement −27.5 W and 43.4 W. Additionally, CVT was strongly correlated AnT (rp = 0.86, p < 0.001 and reproduced this marker well (rc = 0.81. We conclude, that cardiac vagal threshold derived from compression entropy time course can be useful to assess physical fitness in an uncomplicated way.

  13. Heart rate variability in type 2 diabetes mellitus.

    Science.gov (United States)

    Stuckey, Melanie I; Petrella, Robert J

    2013-01-01

    Heart rate variability (HRV) is a noninvasive measure of cardiac autonomic modulation. Time and frequency domain measures have primarily been examined in patients with type 2 diabetes mellitus (T2D). Not only do frequency domain HRV parameters tend to be reduced in T2D, but healthy individuals with low HRV are also more likely to develop T2D. Furthermore, patients with T2D with low HRV have an increased prevalence of complications and risk of mortality compared with those with normal autonomic function. These findings provide support for the use of HRV as a risk indicator in T2D. Exercise is considered an important component to T2D prevention and treatment strategies. To date, few studies have examined the changes in HRV with exercise in T2D. One study showed changes in resting HRV, two studies showed changes in HRV during or following acute stressors, and one study showed no changes in HRV but improvements in baroreflex sensitivity. The most pronounced changes in HRV were realized following the exercise intervention with the greatest frequency of supervised exercise sessions and with the greatest intensity and duration of exercise bouts. These findings suggest that exercise following current American College of Sports Medicine/American Diabetes Association guidelines may be important in the prevention and treatment of T2D to improve autonomic function and reduce the risk of complications and mortality.

  14. Towards 24/7 continuous heart rate monitoring.

    Science.gov (United States)

    Tarniceriu, Adrian; Parak, Jakub; Renevey, Philippe; Nurmi, Marko; Bertschi, Mattia; Delgado-Gonzalo, Ricard; Korhonen, Ilkka

    2016-08-01

    Heart rate (HR) and HR variability (HRV) carry rich information about physical activity, mental and physical load, physiological status, and health of an individual. When combined with activity monitoring and personalized physiological modelling, HR/HRV monitoring may be used for monitoring of complex behaviors and impact of behaviors and external factors on the current physiological status of an individual. Optical HR monitoring (OHR) from wrist provides a comfortable and unobtrusive method for HR/HRV monitoring and is better adhered by users than traditional ECG electrodes or chest straps. However, OHR power consumption is significantly higher than that for ECG based methods due to the measurement principle based on optical illumination of the tissue. We developed an algorithmic approach to reduce power consumption of the OHR in 24/7 HR trending. We use continuous activity monitoring and a fast converging frequency domain algorithm to derive a reliable HR estimate in 7.1s (during outdoor sports, in average) to 10.0s (during daily life). The method allows >80% reduction in power consumption in 24/7 OHR monitoring when average HR monitoring is targeted, without significant reduction in tracking accuracy.

  15. Heart rate variability interventions for concussion and rehabilitation.

    Science.gov (United States)

    Conder, Robert L; Conder, Alanna A

    2014-01-01

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

  16. Heart rate never lies: interventional cardiologist and Braude's quote revised.

    Science.gov (United States)

    Cook, Stéphane; Stauffer, Jean-Christophe; Goy, Jean-Jacques; Graf, Denis; Puricel, Serban; Frobert, Aurélien; Muller, Olivier; Togni, Mario; Arroyo, Diego

    2016-01-01

    Interventional cardiologists may be immune to stress, allowing them to perform complex percutaneous interventions under pressure. To assess heart rate (HR) variations as a surrogate marker of stress of interventional cardiologists during percutaneous cardiac procedures and in every-day life. This is a single-centre observational study including a total of six male interventional cardiologists performing coronary interventions and pacemaker implantations. Participants were asked to record their HR with the Apple Watch Device during procedures, every-day life and control activities such as outpatient consultations, sport, marital conflicts and sexual intercourse. Average daily HR was 88±17 bpm. During work days, HR increased significantly during procedures (90±17 bpm) compared with days outside the cathlab (87±17 bpm, p=0.02). The average HR was higher during a regular week working (88±16 bpm) compared with weekends off (84±18 bpm, p=0.002). Complex cardiac procedures were associated with higher HR up to 122 bpm. Peak HR were higher during physical exertion. Of note, participants complained of hypersexuality and mania after night shifts. Work and especially percutaneous cardiac procedures increase HR independently of physical exertion suggesting that interventional cardiologists experience mental stress and emotions.

  17. Heart Rate Variability Analysis in Patients with Allergic Rhinitis

    Directory of Open Access Journals (Sweden)

    Ming-Ying Lan

    2013-01-01

    Full Text Available Background. Very few studies investigate the role of the autonomic nervous system in allergic rhinitis. In this study, we evaluated the autonomic nervous system in allergic rhinitis patients using heart rate variability (HRV analysis. Methods. Eleven patients with allergic rhinitis and 13 healthy controls, aged between 19 and 40 years old, were enrolled in the study. Diagnosis of allergic rhinitis was based on clinical history, symptoms, and positive Phadiatop test. Electrocardiographic recordings on the sitting and supine positions were obtained for HRV analysis. Results. In the supine position, there were no significant statistical differences in very-low-frequency power (VLF, ≤0.04 Hz, low-frequency power (LF, 0.04–0.15 Hz, high-frequency power (HF, 0.15–0.40 Hz, and the ratio of LF to HF (LF/HF between the patient and control groups. The mean RR intervals significantly increased, while LF% and LF/HF significantly decreased in the patient group in the sitting position. Moreover, mean RR intervals, LF, and LF/HF, which were significantly different between the two positions in the control group, did not show a significant change with the posture change in the patient group. Conclusion. These suggest that patients with allergic rhinitis may have poor sympathetic modulation in the sitting position. Autonomic dysfunction may therefore play a role in the pathophysiology of allergic rhinitis.

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

    Directory of Open Access Journals (Sweden)

    Florian eChouchou

    2014-12-01

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

  19. Heart rates in hospitalized children by age and body temperature.

    Science.gov (United States)

    Daymont, Carrie; Bonafide, Christopher P; Brady, Patrick W

    2015-05-01

    Heart rate (HR) is frequently used by clinicians in the hospital to assess a patient's severity of illness and make treatment decisions. We sought to develop percentiles that characterize the relationship of expected HR by age and body temperature in hospitalized children and to compare these percentiles with published references in both primary care and emergency department (ED) settings. Vital sign data were extracted from electronic health records of inpatients temperature measurement pairs from each admission. Measurements from 60% of patients were used to derive the percentile curves, with the remainder used for validation. We compared our upper percentiles with published references in primary care and ED settings. We used 60,863 observations to derive the percentiles. Overall, an increase in body temperature of 1°C was associated with an increase of ∼ 10 beats per minute in HR, although there were variations across age and temperature ranges. For infants and young children, our upper percentiles were lower than in primary care and ED settings. For school-age children, our upper percentiles were higher. We characterized expected HR by age and body temperature in hospitalized children. These percentiles differed from references in primary care and ED settings. Additional research is needed to evaluate the performance of these percentiles for the identification of children who would benefit from further evaluation or intervention for tachycardia. Copyright © 2015 by the American Academy of Pediatrics.

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

    DEFF Research Database (Denmark)

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

    2001-01-01

    , 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......-202) (mean and range) at sea level to 189 (179-200), 182 (172-189), 175 (166-183), and 165 (162-169) in the acute hypoxic conditions. Peak HR did not decrease further after 4 and 8 h at 4300 m compared to the acute exposure at this altitude. Between barometric pressures of 518 and 355 mmHg (approximately...... 3300 and 6300 m), peak HR decreased linearly: peak HR(hypobaria) = peak HR(sea level) - 0.135 x [hypobaria(3100) - hypobaria (mmHg)]; or peak HR(altitude) = peak HR(sea level) - 0.15 x (altitude - 3100 m). This corresponds to approximately 1-beat x min(-1) reduction in peak HR for every 7-mmHg decrease...

  1. Heart Rate Variability Discriminates Competitive Levels in Professional Soccer Players.

    Science.gov (United States)

    Proietti, Riccardo; di Fronso, Selenia; Pereira, Lucas A; Bortoli, Laura; Robazza, Claudio; Nakamura, Fabio Y; Bertollo, Maurizio

    2017-06-01

    Heart rate variability (HRV) has been increasingly used to monitor team sports athletes. Besides the traditional time domain indices (i.e., the SD of successive RR intervals [SDNN] and the root mean square difference of successive normal RR intervals [RMSSD]), recently the use of the stress score (SS), which is an inverse function of the SD2 index derived from the Poincaré plot, and the sympathetic/parasympathetic ratio (S/PS) to monitor soccer players has been proposed. However, the reliability of these new indices and the ability of HRV to differentiate between soccer competitive levels are unknown. The aim of this study was to analyze the reliability of the different HRV-derived indices in professional soccer players during the competitive period and to compare HRV of professional soccer players from 3 teams of distinct competitive levels (i.e., Italian Second Division [2D], European League [EL], and Champions League [CL]). Fifty-four male professional soccer players from 3 different teams of 2 European countries (Italy and Germany) participated in the study. The intraclass correlation coefficient values of the HRV indices varied from 0.78 (very large) to 0.90 (near perfect). The coefficient of variation (CV) values for RMSSD and SDNN were all soccer players and is able to differentiate between international- and national-level players.

  2. Effect of propranolol on heart rate variability in hyperthyroidism.

    Science.gov (United States)

    Tankeu, Aurel T; Azabji-Kenfack, Marcel; Nganou, Chris-Nadège; Ngassam, Eliane; Kuate-Mfeukeu, Liliane; Mba, Camille; Dehayem, Mesmin Y; Mbanya, Jean-Claude; Sobngwi, Eugene

    2018-02-22

    We aimed to determine the effect of propanolol on heart rate variability (HRV) in hyperthyroidism before antithyroid treatment. This was a before and after study, on ten patients presenting overt hyperthyroidism naïve to treatment. In each patient, a resting electrocardiogram was done followed by estimation of cardiac autonomic dysfunction during five maneuvers (Ewing battery tests). Long term HRV measurement was done using 24 h ambulatory electrocardiographic recording. This automatically provided estimation of HRV using SDNN and RMSSD index, LF, HF, and HF/LF ratio. After baseline investigations, 40 mg of propanolol was given twice a day for 3 days and same parameters were measured after 72 h of treatment. Our patients were aged 40 ± 10 years. Propanolol significantly reduced RR and HR interval (669 ms vs 763 ms and 91 vs 79 bpm; p hyperthyroidism. Trial registration NCT03393728 "Retrospectively registered".

  3. Feature selection using genetic algorithms for fetal heart rate analysis

    International Nuclear Information System (INIS)

    Xu, Liang; Redman, Christopher W G; Georgieva, Antoniya; Payne, Stephen J

    2014-01-01

    The fetal heart rate (FHR) is monitored on a paper strip (cardiotocogram) during labour to assess fetal health. If necessary, clinicians can intervene and assist with a prompt delivery of the baby. Data-driven computerized FHR analysis could help clinicians in the decision-making process. However, selecting the best computerized FHR features that relate to labour outcome is a pressing research problem. The objective of this study is to apply genetic algorithms (GA) as a feature selection method to select the best feature subset from 64 FHR features and to integrate these best features to recognize unfavourable FHR patterns. The GA was trained on 404 cases and tested on 106 cases (both balanced datasets) using three classifiers, respectively. Regularization methods and backward selection were used to optimize the GA. Reasonable classification performance is shown on the testing set for the best feature subset (Cohen's kappa values of 0.45 to 0.49 using different classifiers). This is, to our knowledge, the first time that a feature selection method for FHR analysis has been developed on a database of this size. This study indicates that different FHR features, when integrated, can show good performance in predicting labour outcome. It also gives the importance of each feature, which will be a valuable reference point for further studies. (paper)

  4. Estimation of human core temperature from sequential heart rate observations

    International Nuclear Information System (INIS)

    Buller, Mark J; Tharion, William J; Cheuvront, Samuel N; Montain, Scott J; Kenefick, Robert W; Castellani, John; Latzka, William A; Hoyt, Reed W; Roberts, Warren S; Richter, Mark; Jenkins, Odest Chadwicke

    2013-01-01

    Core temperature (CT) in combination with heart rate (HR) can be a good indicator of impending heat exhaustion for occupations involving exposure to heat, heavy workloads, and wearing protective clothing. However, continuously measuring CT in an ambulatory environment is difficult. To address this problem we developed a model to estimate the time course of CT using a series of HR measurements as a leading indicator using a Kalman filter. The model was trained using data from 17 volunteers engaged in a 24 h military field exercise (air temperatures 24–36 °C, and 42%–97% relative humidity and CTs ranging from 36.0–40.0 °C). Validation data from laboratory and field studies (N = 83) encompassing various combinations of temperature, hydration, clothing, and acclimation state were examined using the Bland–Altman limits of agreement (LoA) method. We found our model had an overall bias of −0.03 ± 0.32 °C and that 95% of all CT estimates fall within ±0.63 °C (>52 000 total observations). While the model for estimating CT is not a replacement for direct measurement of CT (literature comparisons of esophageal and rectal methods average LoAs of ±0.58 °C) our results suggest it is accurate enough to provide practical indication of thermal work strain for use in the work place. (paper)

  5. Estimation of human core temperature from sequential heart rate observations.

    Science.gov (United States)

    Buller, Mark J; Tharion, William J; Cheuvront, Samuel N; Montain, Scott J; Kenefick, Robert W; Castellani, John; Latzka, William A; Roberts, Warren S; Richter, Mark; Jenkins, Odest Chadwicke; Hoyt, Reed W

    2013-07-01

    Core temperature (CT) in combination with heart rate (HR) can be a good indicator of impending heat exhaustion for occupations involving exposure to heat, heavy workloads, and wearing protective clothing. However, continuously measuring CT in an ambulatory environment is difficult. To address this problem we developed a model to estimate the time course of CT using a series of HR measurements as a leading indicator using a Kalman filter. The model was trained using data from 17 volunteers engaged in a 24 h military field exercise (air temperatures 24-36 °C, and 42%-97% relative humidity and CTs ranging from 36.0-40.0 °C). Validation data from laboratory and field studies (N = 83) encompassing various combinations of temperature, hydration, clothing, and acclimation state were examined using the Bland-Altman limits of agreement (LoA) method. We found our model had an overall bias of -0.03 ± 0.32 °C and that 95% of all CT estimates fall within ±0.63 °C (>52 000 total observations). While the model for estimating CT is not a replacement for direct measurement of CT (literature comparisons of esophageal and rectal methods average LoAs of ±0.58 °C) our results suggest it is accurate enough to provide practical indication of thermal work strain for use in the work place.

  6. Heart rate variability and implication for sport concussion.

    Science.gov (United States)

    Bishop, Scott A; Dech, Ryan T; Guzik, Przemyslaw; Neary, J Patrick

    2017-11-16

    Finding sensitive and specific markers for sports-related concussion is both challenging and clinically important. Such biomarkers might be helpful in the management of patients with concussion (i.e. diagnosis, monitoring and risk prediction). Among many parameters, blood flow-pressure metrics and heart rate variability (HRV) have been used to gauge concussion outcomes. Reports on the relation between HRV and both acute and prolonged concussion recovery are conflicting. While some authors report on differences in the low-frequency (LF) component of HRV during postural manipulations and postexercise conditions, others observe no significant differences in various HRV measures. Despite the early success of using the HRV LF for concussion recovery, the interpretation of the LF is debated. Recent research suggests the LF power is a net effect of several intrinsic modulatory factors from both sympathetic and parasympathetic branches of the autonomic nervous system, vagally mediated baroreflex and even some respiratory influences at lower respiratory rate. There are only a few well-controlled concussion studies that specifically examine the contribution of the autonomic nervous system branches with HRV for concussion management. This study reviews the most recent HRV- concussion literature and the underlying HRV physiology. It also highlights cerebral blood flow studies related to concussion and the importance of multimodal assessment of various biological signals. It is hoped that a better understanding of the physiology behind HRV might generate cost-effective, repeatable and reliable protocols, all of which will improve the interpretation of HRV throughout concussion recovery. © 2017 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

  7. The order and volume fill rates in inventory control systems

    DEFF Research Database (Denmark)

    Thorstenson, Anders; Larsen, Christian

    2014-01-01

    This paper differentiates between an order (line) fill rate and a volume fill rate and specifies their performance for different inventory control systems. When the focus is on filling complete customer orders rather than total demanded quantity the order fill rate would be the preferred service...... level measure. The main result shows how the order and volume fill rates are related in magnitude. Earlier results derived for a single-item, single-stage, continuous review inventory system with backordering and constant lead times controlled by a base-stock policy are extended in different directions...... extensions consider more general inventory control review policies with backordering, as well as some relations between service measures. A particularly important result in the paper concerns an alternative service measure, the customer order fill rate, and shows how this measure always exceeds the other two...

  8. The effect of metaprolol alone and metaprolol plus bromazepam on heart rate and heart rate variability during multislice computed tomography angiography

    International Nuclear Information System (INIS)

    Tuyyab, F.; Naeem, M.Y.; Maken, G.R.; Najfi, M.H.; Hassan, F.

    2012-01-01

    Objective: The purpose of this study was to determine the effect of metaprolol alone and metaprolol plus bromazepam on heart rate and heart rate variability during multi slice computed tomography (MSCT) angiography. Methodology: This was a Double blind randomized controlled trial was conducted at AFIC/NIHD, Rawalpindi, from May 2011 to November 2011. Patients undergoing first MSCT angiography meeting inclusion criteria with heart rates (HR) more than 80 beats/min were included. Patients were randomized in to two groups using random numbers table. Group 1 was administered metaprolol plus placebo while group 2 was administered metaprolol plus bromazepam one hour before the scan. Both groups had scans under strictly similar conditions. HR before and during scan along with heart rate variability (HRV) were recorded. Results: A total of 80 patients were included. Patients mean age was 49 + 13, 57 % were males while 43 % were females. Risk factor profile was similar in both groups. HR reduction in group 1 was 15+ 6.0 and in group 2, was 21+9.0 (p= 0.002). HRV in group 1 was 3.9 + 1.32 and in group 2 was 2.3 + 1.0 (p= 0.003). Group 2 had significantly lower HR and significantly less HRV as compared with group 1. Conclusion: Combination of bromazepam and metaprolol results in significant and further reduction in heart rate and heart rate variability than metaprolol alone. Both drugs can be used together for a better control of heart rate and heart rate variability during MSCT angiography for improving the quality of images. (author)

  9. With age a lower individual breathing reserve is associated with a higher maximal heart rate.

    Science.gov (United States)

    Burtscher, Martin; Gatterer, Hannes; Faulhaber, Martin; Burtscher, Johannes

    2018-01-01

    Maximal heart rate (HRmax) is linearly declining with increasing age. Regular exercise training is supposed to partly prevent this decline, whereas sex and habitual physical activity do not. High exercise capacity is associated with a high cardiac output (HR x stroke volume) and high ventilatory requirements. Due to the close cardiorespiratory coupling, we hypothesized that the individual ventilatory response to maximal exercise might be associated with the age-related HRmax. Retrospective analyses have been conducted on the results of 129 consecutively performed routine cardiopulmonary exercise tests. The study sample comprised healthy subjects of both sexes of a broad range of age (20-86 years). Maximal values of power output, minute ventilation, oxygen uptake and heart rate were assessed by the use of incremental cycle spiroergometry. Linear multivariate regression analysis revealed that in addition to age the individual breathing reserve at maximal exercise was independently predictive for HRmax. A lower breathing reserve due to a high ventilatory demand and/or a low ventilatory capacity, which is more pronounced at a higher age, was associated with higher HRmax. Age explained the observed variance in HRmax by 72% and was improved to 83% when the variable "breathing reserve" was entered. The presented findings indicate an independent association between the breathing reserve at maximal exercise and maximal heart rate, i.e. a low individual breathing reserve is associated with a higher age-related HRmax. A deeper understanding of this association has to be investigated in a more physiological scenario. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Decreased right heart blood volume determined by magnetic resonance imaging: evidence of central underfilling in cirrhosis

    DEFF Research Database (Denmark)

    Møller, S; Søndergaard, L; Møgelvang, J

    1995-01-01

    mL, NS), and left atrial volume (70 vs. 57 mL, P = .08) were normal or slightly increased. The right ejection fraction (68% vs. 53%, P fraction was slightly reduced (61% vs. 69%, NS). The central and arterial blood volume (CBV), assessed......Whether the central blood volume is reduced or expanded in cirrhosis is still under debate. Accordingly, the current study was undertaken to assess the volume of the heart cavities. Ten cirrhotic patients and matched controls had their right and left ventricular end-diastolic volumes (RVDV and LVDV...... as the cardiac output (CO) multiplied by the central circulation time, was significantly decreased (1.47 vs. 1.81 L, P blood volume (4.43 vs. 3.64 L, P

  11. Epicardial adipose tissue volume estimation by postmortem computed tomography of eviscerated hearts

    DEFF Research Database (Denmark)

    Hindsø, Louise; Jakobsen, Lykke S; Jacobsen, Christina

    2017-01-01

    Epicardial adipose tissue (EAT) may play a role in the development of coronary artery disease. The purpose of this study was to evaluate a method based on postmortem computed tomography (PMCT) for the estimation of EAT volume. We PMCT-scanned the eviscerated hearts of 144 deceased individuals, wh...

  12. The study of dose variation and change of heart volume using 4D-CT in left breast radiation therapy

    International Nuclear Information System (INIS)

    Park, Seon Mi; Cheon, Geum Seong; Heo, Gyeong Hun; Shin, Sung Pil; Kim, Kwang Seok; Kim, Chang Uk; Kim, Hoi Nam

    2013-01-01

    We investigate the results of changed heart volume and heart dose in the left breast cancer patients while considering the movements of respiration. During the months of March and May in 2012, we designated the 10 patients who had tangential irradiation with left breast cancer in the department of radiation Oncology. With acquired images of free breathing pattern through 3D and 4D CT, we had planed enough treatment filed for covered up the whole left breast. It compares the results of the exposed dose and the volume of heart by DVH (Dose Volume histogram). Although total dose was 50.4 Gy (1.8 Gy/28 fraction), reirradiated 9 Gy (1.8 Gy/5 Fraction) with PTV (Planning Target Volume) if necessary. It compares the results of heart volume and heart dose with the free breathing in 3D CT and 4D CT. It represents the maximum difference volume of heart is 40.5%. In addition, it indicated the difference volume of maximum and minimum, average are 8.8% and 27.9%, 37.4% in total absorbed dose of heart. In case of tangential irradiation (opposite beam) in left breast cancer patients, it is necessary to consider the changed heart volume by the respiration of patient and the heartbeat of patient

  13. Heart rate variability in patients with systemic lupus erythematosus: a systematic review and methodological considerations.

    Science.gov (United States)

    Matusik, P S; Matusik, P T; Stein, P K

    2018-07-01

    Aim The aim of this review was to summarize current knowledge about the scientific findings and potential clinical utility of heart rate variability measures in patients with systemic lupus erythematosus. Methods PubMed, Embase and Scopus databases were searched for the terms associated with systemic lupus erythematosus and heart rate variability, including controlled vocabulary, when appropriate. Articles published in English and available in full text were considered. Finally, 11 publications were selected, according to the systematic review protocol and were analyzed. Results In general, heart rate variability, measured in the time and frequency domains, was reported to be decreased in patients with systemic lupus erythematosus compared with controls. In some systemic lupus erythematosus studies, heart rate variability was found to correlate with inflammatory markers and albumin levels. A novel heart rate variability measure, heart rate turbulence onset, was shown to be increased, while heart rate turbulence slope was decreased in systemic lupus erythematosus patients. Reports of associations of changes in heart rate variability parameters with increasing systemic lupus erythematosus activity were inconsistent, showing decreasing heart rate variability or no relationship. However, the low/high frequency ratio was, in some studies, reported to increase with increasing disease activity or to be inversely correlated with albumin levels. Conclusions Patients with systemic lupus erythematosus have abnormal heart rate variability, which reflects cardiac autonomic dysfunction and may be related to inflammatory cytokines but not necessarily to disease activity. Thus measurement of heart rate variability could be a useful clinical tool for monitoring autonomic dysfunction in systemic lupus erythematosus, and may potentially provide prognostic information.

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

    Science.gov (United States)

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

    2015-08-01

    Reduced cardiovascular responses to psychological stressors have been found to be associated with both obesity and negative affect in adults, but have been less well studied in children and adolescent populations. These findings have most often been interpreted as reflecting reduced sympathetic nervous system response, perhaps associated with heightened baseline sympathetic activation among the obese and those manifesting negative affect. However, obesity and negative affect may themselves be correlated, raising the question of whether they both independently affect cardiovascular reactivity. The present study thus examined the separate effects of obesity and negative affect on both cardiovascular and skin conductance responses to stress (e.g., during a serial subtraction math task) in adolescents, while controlling for baseline levels of autonomic activity during rest. Both obesity and negative affect had independent and negative associations with cardiovascular reactivity, such that reduced stress responses were apparent for obese adolescents and those with high levels of negative affect. In contrast, neither obesity nor negative affect was related to skin conductance responses to stress, implicating specifically noradrenergic mechanisms rather than sympathetic mechanisms generally as being deficient. Moreover, baseline heart rate was unrelated to obesity in this sample, which suggests that heightened baseline of sympathetic activity is not necessary for the reduced cardiovascular reactivity to stress. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Effect of mibefradil on heart rate variability in patients with chronic heart failure

    NARCIS (Netherlands)

    Brouwer, J; de Kam, PJ; Haaksma, J; Crijns, HJGM; van Veldhuisen, DJ

    2000-01-01

    Background: Mibefradil was recently withdrawn from the market because of an unfavorable clinical profile in patients with chronic heart failure. Although drug interactions appear to play a role, other mechanisms such as proarrhythmia and autonomic deterioration could also be relevant. Chronic heart

  16. Heart rate recovery in elite Spanish male athletes.

    Science.gov (United States)

    Peinado, A B; Benito, P J; Barriopedro, M; Lorenzo, I; Maffulli, N; Calderón, F J

    2014-06-01

    During postexercise recovery, heart rate (HR) initially falls rapidly, followed by a period of slower decrease, until resting values are reached. The aim of the present work was to examine the differences in the recovery heart rate (RHR) between athletes engaged in static and dynamic sports. The study subjects were 294 federated sportsmen competing at the national and international level in sports classified using the criteria of Mitchell et al. as either prevalently static (N.=89) or prevalently dynamic (N.=205). Within the dynamic group, the subjects who practised the most dynamic sports were assigned to further subgroups: triathlon (N.=20), long distance running (N.=58), cycling (N.=28) and swimming (N.=12). All athletes were subjected to a maximum exertion stress test and their HR recorded at 1, 2, 3 and 4 min (RHR1,2,3,4) into the HR recovery period. The following indices of recovery (IR) were then calculated: IR1=(HRpeak-RHR1,2,3,4)/(HRmax-HRrest)*100, IR2=(HRpeak-RHR1,2,3,4)/(HRmax/HRpeak), and IR3=HRpeak-RHR1,2,3,4. The differences in the RHR and IR for the static and dynamic groups were examined using two way ANOVA. The RHR at minutes 2 (138.7±15.2 vs. 134.8±14.4 beats·min⁻¹) and 3 (128.5±15.2 vs. 123.3±14.4 beats·min⁻¹) were significantly higher for the static group (Group S) than the dynamic group (Group D), respectively. Significant differences were seen between Group D and S with respect to IR1 at minutes 1 (26.4±8.7 vs. 24.8±8.4%), 2 (43.8±8.1 vs. 41.5±7.8%), 3 (52.1±8.3 vs. 49.1±8%) and 4 (56.8±8.6 vs. 55.4±7.4%) of recovery. For IR2, significant differences were seen between the same groups at minutes 2 (59.7±12.5 vs. 55.9±10.8 beats·min⁻¹) and 3 (71.0±13.5 vs. 66.1±11.4 beats·min⁻¹) of recovery. Finally, for IR3, the only significant difference between Group D and S was recorded at minute 3 of recovery (72.2±12.5 vs. 66.2±11.5 beats·min⁻¹). This work provides information on RHR of a large population of elite

  17. Reiki improves heart rate homeostasis in laboratory rats.

    Science.gov (United States)

    Baldwin, Ann Linda; Wagers, Christina; Schwartz, Gary E

    2008-05-01

    To determine whether application of Reiki to noise-stressed rats can reduce their heart rates (HRs) and blood pressures. In a previous study, we showed that exposure of rats to 90 dB white noise for 15 minutes caused their HRs and blood pressures to significantly increase. Reiki has been shown to significantly decrease HR and blood pressure in a small group of healthy human subjects. However, use of humans in such studies has the disadvantage that experimental interpretations are encumbered by the variable of belief or skepticism regarding Reiki. For that reason, noise-stressed rats were used as an animal model to test the efficacy of Reiki in reducing elevated HR and blood pressure. Three unrestrained, male Sprague-Dawley rats implanted with radiotelemetric transducers were exposed daily for 8 days to a 15-minute white noise regimen (90 dB). For the last 5 days, the rats received 15 minutes of Reiki immediately before the noise and during the noise period. The experiment was repeated on the same animals but using sham Reiki. The animals were housed in a quiet room in University of Arizona Animal Facility. Mean HRs and blood pressure were determined before Reiki/sham Reiki, during Reiki/sham Reiki, and during the noise in each case. Reiki, but not sham Reiki, significantly reduced HR compared to initial values. With Reiki, there was a high correlation between change in HR and initial HR, suggesting a homeostatic effect. Reiki, but not sham Reiki, significantly reduced the rise in HR produced by exposure of the rats to loud noise. Neither Reiki nor sham Reiki significantly affected blood pressure. Reiki is effective in modulating HR in stressed and unstressed rats, supporting its use as a stress-reducer in humans.

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

    Science.gov (United States)

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

    2014-05-01

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

  19. Smartphone-Enabled Heart Rate Variability and Acute Mountain Sickness.

    Science.gov (United States)

    Mellor, Adrian; Bakker-Dyos, Josh; OʼHara, John; Woods, David Richard; Holdsworth, David A; Boos, Christopher J

    2018-01-01

    The autonomic system and sympathetic activation appears integral in the pathogenesis of acute mountain sickness (AMS) at high altitude (HA), yet a link between heart rate variability (HRV) and AMS has not been convincingly shown. In this study we investigated the utility of the smartphone-derived HRV score to predict and diagnose AMS at HA. Twenty-one healthy adults were investigated at baseline at 1400 m and over 10 days during a trek to 5140 m. HRV was recorded using the ithlete HRV device. Acute mountain sickness occurred in 11 subjects (52.4%) at >2650 m. HRV inversely correlated with AMS Scores (r = -0.26; 95% CI, -0.38 to -0.13: P HRV significantly fell at 3700, 4100, and 5140 m versus low altitude. HRV scores were lower in those with both mild (69.7 ± 14.0) and severe AMS (67.1 ± 13.1) versus those without AMS (77.5 ± 13.1; effect size n = 0.043: P = 0.007). The HRV score was weakly predictive of severe AMS (AUC 0.74; 95% CI, 0.58-0.89: P = 0.006). The change (delta) in the HRV Score (compared with baseline at 1400 m) was a moderate diagnostic marker of severe AMS (AUC 0.80; 95% CI, 0.70-0.90; P = 0.0004). A fall in the HRV score of >5 had a sensitivity of 83% and specificity of 60% to identify severe AMS (likelihood ratio 1.9). Baseline HRV at 1400 m was not predictive of either AMS at higher altitudes. The ithlete HRV score can be used to help in the identification of severe AMS; however, a baseline score is not predictive of future AMS development at HA.

  20. Heart Rate Variability and Autonomic Modulations in Preeclampsia.

    Directory of Open Access Journals (Sweden)

    Shaza M Musa

    Full Text Available Although the exact pathophysiology of preeclampsia is not well understood, autonomic nervous system imbalance is suggested as one of the main factors.To investigate heart rate variability (HRV and autonomic modulations in Sudanese pregnant women with preeclampsia.A case-control study (60 women in each arm was conducted at Omdurman Maternity Hospital-Sudan, during the period from June to August, 2014. Cases were women presented with preeclampsia and healthy pregnant women were the controls. Studied groups were matched for important determinants of HRV. Natural logarithm (Ln of total power (TP, high frequency (HF, low frequency (LF and very low frequency (VLF were used to determine HRV. Normalized low and high frequencies (LF Norm and HF Norm were used to evaluate sympathetic and parasympathetic autonomic modulations respectively.Patients with preeclampsia achieved significantly higher LF Norm [49.80 (16.25 vs. 44.55 (19.15, P = 0.044] and LnLF/HF [0.04 (0.68 vs. -0.28 (0.91, P = 0.023] readings, but lower HF Norm [49.08 (15.29 vs. 55.87 (19.56, P = 0.012], compared with healthy pregnant women. Although all other HRV measurements were higher in the patients with preeclampsia compared with the controls, only LnVLF [4.50 (1.19 vs. 4.01 (1.06, P = 0.017] and LnLF [4.01 (1.58 vs. 3.49 (1.23, P = 0.040] reached statistical significance.The study adds further evidence for the dominant cardiac sympathetic modulations on patients with preeclampsia, probably secondary to parasympathetic withdrawal in this group. However, the higher LnVLF and LnLF readings achieved by preeclamptic women compared with the controls are unexpected in the view that augmented sympathetic modulations usually depresses all HRV parameters including these two measures.

  1. Heart Rate Response of Professional Musicians When Playing Music.

    Science.gov (United States)

    Vellers, Heather L; Irwin, Conor; Lightfoot, J T

    2015-06-01

    The primary aim was to determine the level of physiological stress evoked while playing music in a standing position as indicated by heart rate (HR) response. A secondary aim was to analyze the effect of music genre (classic rock, western, contemporary Christian, and metal rock) on the relative HR response. Lastly, we considered potential physiological initiators of the music-playing-induced HR response. HR response was monitored in 27 professional musicians (3 women, 24 men) between the ages of 21 and 67 yrs old during rehearsal and public performances. The percent maximal HR (%MHR) evoked was determined by taking a percentage of the age-predicted maximal HR for each musician and comparing the average %MHR in each genre during public and rehearsal events. The role of the potential initiators of these responses (e.g., number of years playing in public, event type, instrument type, tempo, etc.) was determined using multiple regression analyses. The overall average %MHR responses were 52 ± 5% and 59 ± 5% during rehearsal and public performances, respectively, with genre type having a significant effect on the HR response (p=0.01). Body mass index and tempo were each found to be significant contributors to the HR response while playing music (r²=0.506, p=0.001). Playing music professionally evokes considerable increases in HR response, with music genre influencing the level of the physiological response. We concluded that 50% of the HR response while playing music was associated with body mass index, music tempo, and instrument type.

  2. Improving Interprofessional Consistency in Electronic Fetal Heart Rate Interpretation.

    Science.gov (United States)

    Govindappagari, Shravya; Zaghi, Sahar; Zannat, Ferdous; Reimers, Laura; Goffman, Dena; Kassel, Irene; Bernstein, Peter S

    2016-07-01

    Objective To determine if mandatory online training in electronic fetal monitoring (EFM) improved agreement in documentation between obstetric care providers and nurses on labor and delivery. Methods Health care professionals working in obstetrics at our institution were required to complete a course on EFM interpretation. We performed a retrospective chart review of 701 charts including patients delivered before and after the introduction of the course to evaluate agreement among providers in their documentation of their interpretations of the EFM tracings. Results Agreement between provider and nurse documentation at the time of admission improved for variability and accelerations (variability: 91.1 vs. 98.3%, p < 0.001; and accelerations: 75.2 vs. 87.7%, p < 0.001). Similarly, agreement improved at the time of the last note prior to delivery for documentation of variability and accelerations (variability: 82.1 vs. 90.6%, p = 0.001; and accelerations: 56.7 vs. 68.6%, p = 0.0012). Agreement in interpretation of decelerations both at the time of admission and at the time of delivery increased (86.3 vs. 90.6%, p = 0.0787, and 56.7 vs. 61.1%, p = 0.2314, respectively) but was not significant. Conclusion An online EFM course can significantly improve consistency in multidisciplinary documentation of fetal heart rate tracing interpretation. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  3. Heart Rate Variability in Men with Erectile dysfunction

    Directory of Open Access Journals (Sweden)

    Ji Yong Lee

    2011-06-01

    Full Text Available Purpose The objective of this study is to investigate alteration of autonomic nervous system (ANS activity in patients suffering from erectile dysfunction (ED by comparing parameters of heart rate variability (HRV between men with ED and healthy subjects. Methods A retrospective review was performed on 40 ED patients (mean age, 46.0±8.49 years without any disease and 180 healthy control people (mean age, 44.4±7.83 years without ED in our institution from June 2008 to July 2010. And electrocardiographic signals were obtained to measure HRV parameters for both patients and controls in a resting state. Results For the time domain analysis, square root of the mean differences between successive RR intervals (RMSSD representing parasympathetic activity was lower in patients than controls although P-value was not statistically significant (P=0.060. For the frequency domain analysis, high frequency (HF representing parasympathetic activity was lower in patients than controls (P=0.232 and low frequency (LF representing mainly sympathetic activity was higher in patients than controls (P=0.416. Lastly, LF/HF ratio reflecting sympathetic/parasympathetic activity ratio was statistically higher in patients than controls (P=0.027. Conclusions Patients with ED exhibited different HRV parameters compared with normal controls. This suggests that the patients with ED may have some kind of imbalance in the ANS and it may be possible that general imbalance of the ANS is one of the causes of ED. Thus, HRV analysis may give valuable diagnostic information and serve as a rapid screening tool to evaluate altered ANS activity in patients with ED.

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

    Science.gov (United States)

    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 < 0.001) became closer to values of 50 aged-matched healthy controls. Conclusions A 3-week residential programme with intensive volumes of physical activity (15-20 hours per week) enhanced HRV in individuals with MetS. Participants with moderate intensity of training had greater improvements in sympathovagal balance, whereas those with high intensity in resistance training had greater decreases in heart rate and greater increases in very low frequency. Modality-specific relationships were observed between enhanced HRV

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

    Science.gov (United States)

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

    2011-01-01

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

  6. Resemblances of Parents and Twins in Sport Participation and Heart Rate

    NARCIS (Netherlands)

    Boomsma, D.I.; van den Bree, M.B.; Orlebeke, J.F.; Molenaar, P.C.M.

    1989-01-01

    A model to analyze resemblances of twins and parents using LISREL is outlined and applied to sports participation and heart-rate data. Sports participation and heart rate were measured in 44 monozygotic and 46 dizygotic adolescent twin pairs and in their parents. Genetic factors influence variation

  7. Identification of heart rate-associated loci and their effects on cardiac conduction and rhythm disorders

    NARCIS (Netherlands)

    den Hoed, M.A.H.; Eijgelsheim, M.; Esko, T.; Brundel, B.J.; Peal, D.S.; Evans, D.M.; Nolte, I.M.; Segrè, A.V.; Holm, H.; Handsaker, R.E.; Westra, H.J.; Johnson, T.; Isaacs, A.; Yang, L.; Lundby, A.; Zhao, J.H.; Kim, Y.J.; Go, M.J.; Almgren, P.; Bochud, M.; Boucher, G.; Cornelis, M.C.; Gudbjartsson, D.F.; Hadley, D.; van der Harst, P.; Hayward, C.; den Heijer, M.; Igl, W.; Jackson, A.U.; Kutalik, Z.; Luan, J.; Kemp, J.P.; Kristiansson, K.; Ladenvall, C.; Lorentzon, M.; Montasser, M.E.; Njajou, O.T.; O'Reilly, P.F.; Padmanabhan, S.; St Pourcain, B.; Rankinen, T.; Salo, P.; Tanaka, T.; Timpson, N.J.; Vitart, V.; Waite, L.; Wheeler, W.; Zhang, W.; Draisma, H.H.M.; Feitosa, M.F.; Kerr, K.F.; Lind, P.A.; Mihailov, E.; Onland-Moret, N.C.; Song, C.; Weedon, M.N.; Xie, W.; Yengo, L.; Absher, D.; Albert, C.M.; Alonso, A.; Arking, D.E.; de Bakker, P.I.; Balkau, B.; Barlassina, C.; Benaglio, P.; Bis, J.C.; Bouatia-Naji, N.; Brage, S.; Chanock, S.J.; Chines, P.S.; Chung, M.; Darbar, D.; Dina, C.; Dörr, M.; Elliott, P.; Felix, S.B.; Fischer, K.; Fuchsberger, C.; de Geus, E.J.C.; Goyette, P.; Gudnason, V.; Harris, T.B.; Hartikainen, A.L.; Havulinna, A.S.; Heckbert, S.R.; Hicks, A.A.; Hofman, A.; Holewijn, S.; Hoogstra-Berends, F.; Hottenga, J.J.; Jensen, M.K.; Johansson, A.; Junttila, J.; Kääb, S.; Kanon, B.; Ketkar, S.; Khaw, K.T.; Knowles, J.W.; Kooner, A.S.; Kors, J.A.; Kumari, M.; Milani, L.; Laiho, P.; Lakatta, E.G.; Langenberg, C.; Leusink, M.; Liu, Y.; Luben, R.N.; Lunetta, K.L.; Lynch, S.N.; Markus, M.R.; Marques-Vidal, P.; Mateo Leach, I.; McArdle, W.L.; McCarroll, S.A.; Medland, S.E.; Miller, K.A.; Montgomery, G.W.; Morrison, A.C.; Müller-Nurasyid, M.; Navarro, P.; Nelis, M.; O'Connell, J.R.; O'Donnell, C.J.; Ong, K.K.; Newman, A.B.; Peters, A.; Polasek, O.; Pouta, A.; Pramstaller, P.P.; Psaty, B.M.; Rao, D.C.; Ring, S.M.; Rossin, E.J.; Rudan, D.; Sanna, S.; Scott, R.A.; Sehmi, J.S.; Sharp, S.; Shin, J.T.; Singleton, A.B.; Smith, A.V.; Soranzo, N.; Spector, T.D.; Stewart, C.; Stringham, H.M.; Tarasov, K.V.; Uitterlinden, A.G.; Vandenput, L.; Hwang, S.J.; Whitfield, J.B.; Wijmenga, C.; Wild, S.H.; Willemsen, G.; Wilson, J.F.; Witteman, J.C.; Wong, A.; Wong, Q.; Jamshidi, Y.; Zitting, P.; Boer, J.M.; Boomsma, D.I.; Borecki, I.B.; van Duijn, C.M.; Ekelund, U.; Forouhi, N.G.; Froguel, P.; Hingorani, A.D.; Ingelsson, E.; Kivimaki, M.; Kronmal, R.A.; Kuh, D; Lind, L.; Martin, N.G.; Oostra, B.A.; Pedersen, N.L.; Quertermous, T.; Rotter, J.I.; van der Schouw, Y.T.; Verschuren, W.M.; Walker, M.; Albanes, D.; Arnar, D.O.; Assimes, T.L.; Bandinelli, S.; Boehnke, M.; de Boer, R.A.; Bouchard, C.; Caulfield, W.L.; Chambers, J.C.; Curhan, G.; Cusi, D.; Eriksson, J.; Ferrucci, L.; van Gilst, W.H.; Glorioso, N.; de Graaf, J.; Groop, L.; Gyllensten, U.; Hsueh, W.C.; Hu, F.B.; Huikuri, H.V.; Hunter, D.J.; Iribarren, C.; Isomaa, B.; Järvelin, M.R.; Jula, A.; Kähönen, M.; Kiemeney, L.A.; van der Klauw, M.M.; Kooner, J.S.; Kraft, P.; Iacoviello, L.; Lehtimäki, T.; Lokki, M.L.; Mitchell, B.D.; Navis, G.; Nieminen, M.S.; Ohlsson, C.; Poulter, N.R.; Qi, L.; Raitakari, O.T.; Rimm, E.B.; Rioux, J.D.; Rizzi, F.; Rudan, I.; Salomaa, V.; Sever, P.S.; Shields, D.C.; Shuldiner, A.R.; Sinisalo, J.; Stanton, A.V.; Stolk, R.P.; Strachan, D.P.; Tardif, J.C.; Thorsteinsdottir, U.; Tuomilehto, J.; van Veldhuisen, D.J.; Virtamo, J.; Viikari, J.; Vollenweider, P.; Waeber, G.; Widen, E.; Cho, Y.S.; Olsen, J.V.; Visscher, P.M.; Willer, C.J.; Franke, L; Erdmann, J.; Thompson, J.R.; Pfeufer, A.; Sotoodehnia, N.; Newton-Cheh, C.; Ellinor, P.T.; Stricker, B.H.C.; Metspalu, A.; Perola, M.; Beckmann, J.S.; Smith, G.D.; Stefansson, K.; Wareham, N.J.; Munroe, P.B.; Sibon, O.C.M.; Milan, D.J.; Snieder, H.; Samani, N.J.; Loos, R.J.

    2013-01-01

    Elevated resting heart rate is associated with greater risk of cardiovascular disease and mortality. In a 2-stage meta-analysis of genome-wide association studies in up to 181,171 individuals, we identified 14 new loci associated with heart rate and confirmed associations with all 7 previously

  8. iHeartrate: a heart rate controlled in-flight music recommendation system

    NARCIS (Netherlands)

    Liu, H.; Hu, J.; Rauterberg, G.W.M.; Spink, A.J.; Grieco, O.E.; Krips, L.W.S.; Loijens, L.P.J.J.; Noldus, xx; Zimmerman, P.H.

    2010-01-01

    Travel by air, especially long distance, the enclosed environment of the aircraft cabin causes discomfort and even stress to flight passengers. In this paper, we present a new heart rate controlled music recommendation system. Heart rate is used as a stress indicator. If the user is stressed and

  9. Modulations of Heart Rate, ECG, and Cardio-Respiratory Coupling Observed in Polysomnography

    Directory of Open Access Journals (Sweden)

    Thomas Penzel

    2016-10-01

    Full Text Available The cardiac component of cardio-respiratory polysomnography is covered by ECG and heart rate recordings. However their evaluation is often underrepresented in summarizing reports. As complements to EEG, EOG, and EMG, these signals provide diagnostic information for autonomic nervous activity during sleep. This review presents major methodological developments in sleep research regarding heart rate, ECG and cardio-respiratory couplings in a chronological (historical sequence. It presents physiological and pathophysiological insights related to sleep medicine obtained by new technical developments. Recorded nocturnal ECG facilitates conventional heart rate variability analysis, studies of cyclical variations of heart rate, and analysis of ECG waveform. In healthy adults, the autonomous nervous system is regulated in totally different ways during wakefulness, slow-wave sleep, and REM sleep. Analysis of beat-to-beat heart-rate variations with statistical methods enables us to estimate sleep stages based on the differences in autonomic nervous system regulation. Furthermore, up to some degree, it is possible to track transitions from wakefulness to sleep by analysis of heart-rate variations. ECG and heart rate analysis allow assessment of selected sleep disorders as well. Sleep disordered breathing can be detected reliably by studying cyclical variation of heart rate combined with respiration-modulated changes in ECG morphology (amplitude of R wave and T wave.

  10. Modulations of Heart Rate, ECG, and Cardio-Respiratory Coupling Observed in Polysomnography.

    Science.gov (United States)

    Penzel, Thomas; Kantelhardt, Jan W; Bartsch, Ronny P; Riedl, Maik; Kraemer, Jan F; Wessel, Niels; Garcia, Carmen; Glos, Martin; Fietze, Ingo; Schöbel, Christoph

    2016-01-01

    The cardiac component of cardio-respiratory polysomnography is covered by ECG and heart rate recordings. However, their evaluation is often underrepresented in summarizing reports. As complements to EEG, EOG, and EMG, these signals provide diagnostic information for autonomic nervous activity during sleep. This review presents major methodological developments in sleep research regarding heart rate, ECG, and cardio-respiratory couplings in a chronological (historical) sequence. It presents physiological and pathophysiological insights related to sleep medicine obtained by new technical developments. Recorded nocturnal ECG facilitates conventional heart rate variability (HRV) analysis, studies of cyclical variations of heart rate, and analysis of ECG waveform. In healthy adults, the autonomous nervous system is regulated in totally different ways during wakefulness, slow-wave sleep, and REM sleep. Analysis of beat-to-beat heart-rate variations with statistical methods enables us to estimate sleep stages based on the differences in autonomic nervous system regulation. Furthermore, up to some degree, it is possible to track transitions from wakefulness to sleep by analysis of heart-rate variations. ECG and heart rate analysis allow assessment of selected sleep disorders as well. Sleep disordered breathing can be detected reliably by studying cyclical variation of heart rate combined with respiration-modulated changes in ECG morphology (amplitude of R wave and T wave).

  11. Effects of vasoactive intestinal polypeptide on heart rate in relation to vagal cardioacceleration in conscious dogs

    NARCIS (Netherlands)

    Roossien, A; Brunstig, J.R; Nijmeijer, A; Zaagsma, Hans; Zijlstra, W.G

    Objective: The vagal cardiac accelerator (VCA) system takes part in the nervous control of the heart rate. In the present study we tried to adduce evidence that vasoactive intestinal polypeptide (VLP) contributes to vagally induced cardioacceleration. Methods: The effect of VIP on heart rate and

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

    Science.gov (United States)

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

    2015-01-01

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

  13. Variation in heart rate during submaximal exercise: Implications for monitoring training : Implications for monitoring training

    NARCIS (Netherlands)

    Lamberts, R.P.; Lemmink, K.A.P.M.; Durandt, J.J.; Lambert, M.I.

    2004-01-01

    A change in heart rate at a controlled submaximal exercise intensity is used as a marker of training status. However, the standard error of measurement has not been studied systematically, and therefore a change in heart rate, which can be considered relevant, has not been determined. Forty-four

  14. Paradoxical response to an emotional task: Trait characteristics and heart-rate dynamics

    NARCIS (Netherlands)

    Balocchia, R.; Varanini, M.; Paoletti, G.; Mecacci, G.; Santarcangelo, E.L.

    2015-01-01

    The present study evaluated the heart-rate dynamics of subjects reporting decreased (responders) or paradoxically increased relaxation (nonresponders) at the end of a threatening movie. Heart-rate dynamics were characterized by indices extracted through recurrence quantification analysis (RQA) and

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

    Science.gov (United States)

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

    2011-01-01

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

  16. Elevated resting heart rate, physical fitness and all-cause mortality

    DEFF Research Database (Denmark)

    Jensen, Magnus Thorsten; Suadicani, Poul; Hein, Hans Ole

    2013-01-01

    To examine whether elevated resting heart rate (RHR) is an independent risk factor for mortality or a mere marker of physical fitness (VO2Max).......To examine whether elevated resting heart rate (RHR) is an independent risk factor for mortality or a mere marker of physical fitness (VO2Max)....

  17. Aggressive behavior: an alternative model of resting heart rate and sensation seeking.

    Science.gov (United States)

    Wilson, Laura C; Scarpa, Angela

    2014-01-01

    Low resting heart rate is a well-replicated biological correlate of aggression, and sensation seeking is frequently cited as the underlying causal explanation. However, little empirical evidence supports this mediating relationship. Furthermore, the biosocial model of violence and social push theory suggest sensation seeking may moderate the relationship between heart rate and aggression. In a sample of 128 college students (82.0% White; 73.4% female), the current study tested a moderation model as an alternative relationship between resting heart rate and sensation seeking in regard to aggression. Overall, the findings partially supported an interaction effect, whereby the relationship between heart rate and aggression was moderated by sensation seeking. Specifically, the oft-noted relationship between low resting heart rate and increased aggression was found, but only for individuals with low levels of sensation seeking. If replication supports this finding, the results may better inform prevention and intervention work. © 2013 Wiley Periodicals, Inc.

  18. Conventional heart rate variability analysis of ambulatory electrocardiographic recordings fails to predict imminent ventricular fibrillation

    Science.gov (United States)

    Vybiral, T.; Glaeser, D. H.; Goldberger, A. L.; Rigney, D. R.; Hess, K. R.; Mietus, J.; Skinner, J. E.; Francis, M.; Pratt, C. M.

    1993-01-01

    OBJECTIVES. The purpose of this report was to study heart rate variability in Holter recordings of patients who experienced ventricular fibrillation during the recording. BACKGROUND. Decreased heart rate variability is recognized as a long-term predictor of overall and arrhythmic death after myocardial infarction. It was therefore postulated that heart rate variability would be lowest when measured immediately before ventricular fibrillation. METHODS. Conventional indexes of heart rate variability were calculated from Holter recordings of 24 patients with structural heart disease who had ventricular fibrillation during monitoring. The control group consisted of 19 patients with coronary artery disease, of comparable age and left ventricular ejection fraction, who had nonsustained ventricular tachycardia but no ventricular fibrillation. RESULTS. Heart rate variability did not differ between the two groups, and no consistent trends in heart rate variability were observed before ventricular fibrillation occurred. CONCLUSIONS. Although conventional heart rate variability is an independent long-term predictor of adverse outcome after myocardial infarction, its clinical utility as a short-term predictor of life-threatening arrhythmias remains to be elucidated.

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

    Science.gov (United States)

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

    1999-01-01

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

  20. Impact of Narrative Expressive Writing on Heart Rate, Heart Rate Variability, and Blood Pressure After Marital Separation.

    Science.gov (United States)

    Bourassa, Kyle J; Allen, John J B; Mehl, Matthias R; Sbarra, David A

    Divorce is a common stressor that is associated with increased risk for poor long-term physical and mental health. Using an experimental design, the current study examined the impact of expressive writing (EW) on average heart rate (HR), HR variability (HRV), and blood pressure (BP) 7.5 months later. Participants from a community sample of recently separated adults (N = 109) were assigned to one of three conditions: traditional EW, narrative EW, or a control writing condition, and were assessed three times for an average of 7.5 months. Each study visit included 27 minutes of physiological assessment; the primary outcomes at each assessment were mean-level HR, HRV, BP scores averaged across six different tasks. Participants in the traditional EW condition did not significantly differ from control participants in their later HR, HRV, or BP. However, relative to control participants, those in the narrative EW condition had significantly lower HR (B = -3.41, 95% confidence interval = -5.76 to -1.06, p = .004) and higher HRV 7.5 months later (B = 0.41, 95% confidence interval = 0.16 to 0.74, p = .001). When comparing narrative EW participants to those in the traditional EW and control writing as a single group, these effects remained and were moderately sized, Cohen d values of -0.61 and 0.60, respectively, and durable across all task conditions when analyzed in independent models. The writing condition groups did not differ in their later BP. Narrative EW decreased HR and increased HRV after marital separation but did not affect BP. We discuss the possible disconnect between psychology and physiology in response to EW, as well as possible future clinical applications after marital separation.

  1. A healthy heart is not a metronome: An integrative review of the heart’s anatomy and heart rate variability

    Directory of Open Access Journals (Sweden)

    Fredric Bruce Shaffer

    2014-09-01

    Full Text Available 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, Vaschillo, and Vaschillo’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.

  2. Muscular Contraction Mode Differently Affects Autonomic Control During Heart Rate Matched Exercise

    Directory of Open Access Journals (Sweden)

    Matthias eWeippert

    2015-05-01

    Full Text Available The precise contributions of afferent feedback to cardiovascular and respiratory responses to exercise are still unclear. Aim of this crossover study was to assess whether and how autonomic cardiovascular and respiratory control differed in response to dynamic (DYN and isometric contractions (ISO at a similar, low heart rate (HR level. Therefore, 22 healthy males (26.7 ± 3.6 yrs performed two kinds of voluntary exercises at similar HR: ISO and DYN of the right quadriceps femoris muscle. Although HR was eqivalent (82 ± 8 bpm for DYN and ISO, respectively, rating of exertion, blood pressures, and rate pressure product were higher, whereas breathing frequency, minute ventilation, oxygen uptake and carbon dioxide output were significantly lower during ISO. Tidal volume, end-tidal partial pressures of O2 and CO2, respiratory exchange ratio and capillary blood lactate concentration were comparable between both contraction modes. Heart rate variability (HRV indicators, SDNN, HF-Power and LF-Power, representing both vagal and sympathetic influences, were significantly higher during ISO. Sample entropy, a nonlinear measure of HRV was also significantly affected by contraction mode. It can be concluded that, despite the same net effect on HR, the quality of cardiovascular control during low intensity exercise is significantly different between DYN and ISO. HRV analysis indicated a sympatho-vagal coactivation during ISO. Whether mechanoreceptor feedback alone, a change in central command, or the interaction of both mechanisms is the main contributor of the distinct autonomic responses to the different exercise modes remains to be elucidated.

  3. Does treadmill running performance, heart rate and breathing rate response during maximal graded exercise improve after volitional respiratory muscle training?

    Science.gov (United States)

    Radhakrishnan, K; Sharma, V K; Subramanian, S K

    2017-05-10

    Maximal physical exertion in sports usually causes fatigue in the exercising muscles, but not in the respiratory muscles due to triggering of the Respiratory muscle metabo-reflex, a sympathetic vasoconstrictor response leading to preferential increment in blood flow to respiratory muscles. 1 We planned to investigate whether a six week yogic pranayama based Volitional Respiratory Muscle Training (VRMT) can improve maximal Graded Exercise Treadmill Test (GXTT) performance in healthy adult recreational sportspersons. Consecutive, consenting healthy adult recreational sportspersons aged 20.56±2.49 years (n=30), volunteered to 'baseline recording' of resting heart rate (HR), blood pressure (BP), respiratory rate (RR), and Bruce ramp protocol maximal GXTT until volitional exhaustion providing total test time (TTT), derived VO2max, Metabolic Equivalent of Task (METs), HR and BP response during maximal GXTT and drop in recovery HR data. After six weeks of observation, they underwent 'pre-intervention recording' followed by supervised VRMT intervention for 6 weeks (30 minutes a day; 5 days a week) and then 'post-intervention recording'. Repeated measures ANOVA with pairwise t statistical comparison was used to analyse the data. After supervised VRMT, we observed significant decrease in their resting supine RR (prespiratory muscle aerobic capacity, attenuation of respiratory muscle metabo-reflex, increase in cardiac stroke volume and autonomic resetting towards parasympatho-dominance. Yogic Pranayama based VRMT can be used in sports conditioning programme of athletes to further improve their maximal exercise performance, and as part of rehabilitation training during return from injury.

  4. Inner volume leakage during integrated leakage rate testing

    International Nuclear Information System (INIS)

    Glover, J.P.

    1987-01-01

    During an integrated leak rate test (ILRT), the containment structure is maintained at test pressure with most penetrations isolated. Since penetrations typically employ dual isolation, the possibility exists for the inner isolation to leak while the outer holds. In this case, the ILRT instrumentation system would indicate containment out-leakage when, in fact, only the inner volume between closures is being pressurized. The problem is compounded because this false leakage is not readily observable outside of containment by standard leak inspection techniques. The inner volume leakage eventually subsides after the affected volumes reach test pressure. Depending on the magnitude of leakage and the size of the volumes, equalization could occur prior to the end of the pretest stabilization period, or significant false leakages may persist throughout the entire test. Two simple analyses were performed to quantify the effects of inside volume leakages. First, a lower bound for the equalization time was found. A second analysis was performed to find an approximate upper bound for the stabilization time. The results of both analyses are shown

  5. Visualization of heart rate variability of long-term heart transplant patient by transition networks: a case report

    Directory of Open Access Journals (Sweden)

    Joanna eWdowczyk

    2016-03-01

    Full Text Available We present a heart transplant patient at his 17th year of uncomplicated follow-up. Within a frame of routine check out several tests were performed. With such a long and uneventful follow-up some degree of graft reinnervation could be anticipated. However, the patient's electrocardiogram and exercise parameters seemed largely inconclusive in this regard. The exercise heart rate dynamics were suggestive of only mild, if any parasympathetic reinnervation of the graft with persisting sympathetic activation. On the other hand, traditional heart rate variability (HRV indices were inadequately high, due to erratic rhythm resulting from interference of the persisting recipient sinus node or nonconducted atrial parasystole. New tools, originated from network representation of time series, by visualization short-term dynamical patterns, provided a method to discern HRV increase due to reinnervation from other reasons.

  6. Numerical modeling of dynamics of heart rate and arterial pressure during passive orthostatic test

    Science.gov (United States)

    Ishbulatov, Yu. M.; Kiselev, A. R.; Karavaev, A. S.

    2018-04-01

    A model of human cardiovascular system is proposed to describe the main heart rhythm, influence of autonomous regulation on frequency and strength of heart contractions and resistance of arterial vessels; process of formation of arterial pressure during systolic and diastolic phases; influence of respiration; synchronization between loops of autonomous regulation. The proposed model is used to simulate the dynamics of heart rate and arterial pressure during passive transition from supine to upright position. Results of mathematical modeling are compared to original experimental data.

  7. Visibility graph analysis of heart rate time series and bio-marker of congestive heart failure

    Science.gov (United States)

    Bhaduri, Anirban; Bhaduri, Susmita; Ghosh, Dipak

    2017-09-01

    Study of RR interval time series for Congestive Heart Failure had been an area of study with different methods including non-linear methods. In this article the cardiac dynamics of heart beat are explored in the light of complex network analysis, viz. visibility graph method. Heart beat (RR Interval) time series data taken from Physionet database [46, 47] belonging to two groups of subjects, diseased (congestive heart failure) (29 in number) and normal (54 in number) are analyzed with the technique. The overall results show that a quantitative parameter can significantly differentiate between the diseased subjects and the normal subjects as well as different stages of the disease. Further, the data when split into periods of around 1 hour each and analyzed separately, also shows the same consistent differences. This quantitative parameter obtained using the visibility graph analysis thereby can be used as a potential bio-marker as well as a subsequent alarm generation mechanism for predicting the onset of Congestive Heart Failure.

  8. Pre-operative renal volume predicts peak creatinine after congenital heart surgery in neonates.

    Science.gov (United States)

    Carmody, J Bryan; Seckeler, Michael D; Ballengee, Cortney R; Conaway, Mark; Jayakumar, K Anitha; Charlton, Jennifer R

    2014-10-01

    Acute kidney injury is common in neonates following surgery for congenital heart disease. We conducted a retrospective analysis to determine whether neonates with smaller pre-operative renal volume were more likely to develop post-operative acute kidney injury. We conducted a retrospective review of 72 neonates who underwent congenital heart surgery for any lesion other than patent ductus arteriosus at our institution from January 2007 to December 2011. Renal volume was calculated by ultrasound using the prolate ellipsoid formula. The presence and severity of post-operative acute kidney injury was determined both by measuring the peak serum creatinine in the first 7 days post-operatively and by using the Acute Kidney Injury Network scoring system. Using a linear change point model, a threshold renal volume of 17 cm³ was identified. Below this threshold, there was an inverse linear relationship between renal volume and peak post-operative creatinine for all patients (p = 0.036) and the subgroup with a single morphologic right ventricle (p = 0.046). There was a non-significant trend towards more acute kidney injury using Acute Kidney Injury Network criteria in all neonates with renal volume ≤17 cm³ (p = 0.11) and in the subgroup with a single morphologic right ventricle (p = 0.17). Pre-operative renal volume ≤17 cm³ is associated with a higher peak post-operative creatinine and potentially greater risk for post-operative acute kidney injury for neonates undergoing congenital heart surgery. Neonates with a single right ventricle may be at higher risk.

  9. Repeatability of heart rate variability in congenital hypothyroidism as analysed by detrended fluctuation analysis

    International Nuclear Information System (INIS)

    Echeverría, J C; Solís, L I; Pérez, J E; Gaitán, M J; Mandujano, M; Sánchez, M C; González-Camarena, R; Rivera, I R

    2009-01-01

    The analysis of heart rate fluctuations, or heart rate variability (HRV), may be applied to explore children's neurodevelopment. However, previous studies have reported poor reliability (repeatability) of HRV measures in children at rest and during light exercise. Whether the reliability can be improved by controlling variables such as physical activity, breathing rate and tidal volume, or by selecting non-conventional techniques for analysing the data remains as an open question. We evaluated the short-term repeatability of RR-interval data from medicated children with congenital hypothyroidism (CH). The α 1 exponents, obtained by detrended fluctuation analysis (DFA), from the data of 21 children collected at two different sessions were compared. Elapsed days between sessions were 59 ± 33, and data were obtained during 10 min, trying to restrict the children's activity while being seated. We found statistical agreement between the means of α 1 exponents for each session (p = 0.94) and no bias with a low-coefficient variation (9.1%); an intraclass correlation coefficient ri = 0.48 ([0.14 0.72], 95% confidence interval) was also estimated. These findings, which were compared with results obtained by conventional time and frequency techniques, indicate the existence of agreement between the α 1 exponents obtained at each session, thereby providing support concerning the repeatability of HRV data as analysed by DFA in children with congenital hypothyroidism. Of particular interest was also the agreement found by using the central frequency of the high-frequency band and the parameter pNN20, both showing better or similar ri than α 1 (0.77 [0.57 0.89] and 0.51 [0.17 0.74], respectively), yet considerably better repeatability than other conventional time and frequency parameters

  10. Simple platelet markers: Mean platelet volume and congestive heart failure coexistent with periodontal disease. Pilot studies.

    Science.gov (United States)

    Czerniuk, Maciej R; Bartoszewicz, Zbigniew; Dudzik-Niewiadomska, Iwona; Pilecki, Tomasz; Górska, Renata; Filipiak, Krzysztof J

    2017-07-17

    Conducted pilot study concerning mean platelet volume parameter among patients suffering from congestive heart failure and periodontal disease. Examination of dynamic changes of platelet and periodontal markers in group of 50 patients before and an average of 6 months subsequent to professional periodontal treatment. Both platelet and periodontal parameters decreased after periodontal treatment, what is more, the decrease of mean platelet volume (MPV) value due to periodontal disease/mm improvement was shown to be statistically significant (p = 0.05). Improvement of periodontal status may influence decrease of MPV value andincrease of congestive heart failure treatment efficacy and effect patient comfort. It is a new, not frequently used pattern of chronic disease treatment optimalization.

  11. Triboelectric Nanogenerator Enabled Body Sensor Network for Self-Powered Human Heart-Rate Monitoring.

    Science.gov (United States)

    Lin, Zhiming; Chen, Jun; Li, Xiaoshi; Zhou, Zhihao; Meng, Keyu; Wei, Wei; Yang, Jin; Wang, Zhong Lin

    2017-09-26

    Heart-rate monitoring plays a critical role in personal healthcare management. A low-cost, noninvasive, and user-friendly heart-rate monitoring system is highly desirable. Here, a self-powered wireless body sensor network (BSN) system is developed for heart-rate monitoring via integration of a downy-structure-based triboelectric nanogenerator (D-TENG), a power management circuit, a heart-rate sensor, a signal processing unit, and Bluetooth module for wireless data transmission. By converting the inertia energy of human walking into electric power, a maximum power of 2.28 mW with total conversion efficiency of 57.9% was delivered at low operation frequency, which is capable of immediately and sustainably driving the highly integrated BSN system. The acquired heart-rate signal by the sensor would be processed in the signal process circuit, sent to an external device via the Bluetooth module, and displayed on a personal cell phone in a real-time manner. Moreover, by combining a TENG-based generator and a TENG-based sensor, an all-TENG-based wireless BSN system was developed, realizing continuous and self-powered heart-rate monitoring. This work presents a potential method for personal heart-rate monitoring, featured as being self-powered, cost-effective, noninvasive, and user-friendly.

  12. Design of heart rate monitor based on piezoelectric sensor using an Arduino

    Science.gov (United States)

    Setyowati, Veni; Muninggar, Jodelin; Shanti. N. A, Made R. S.

    2017-01-01

    Reading of result heart rate using an acoustic stethoscope needs a particular skill, quiet environment, and hearing sensitivity. This project had the purpose design of a user-friendly automatic heart rate monitor and especially in a noisy area which to eliminate problems and incorrect reading of result. The liquid crystal display shows a heart rate as a result of measurements. The design of the heart rate monitor has two main parts; the signal recorder that a piezoelectric sensor, a filter, and an amplifier as recorder. The second parts was Arduino microcontroller with reinforced. Besides, three supporting buttons provided as the manual switches, the ‘on’, the ‘start’, and ‘reset’ buttons. The values acquired from the heart rate monitor indicate that those were on the Vernier BPS-BTA value range. The measurement error factor of the heart rate monitor then compared to the Vernier BPS-BTA test device was 3.15%. Besides, the value of statistical independent-test indicates that there is no significant difference (P = 0.971) between the heart rate monitor device and the Vernier BPS-BTA. In conclusion, this device was ready to be used because it has almost the same accuracy with the standart device.

  13. Relationships between heart rate and age, bodyweight and breed in 10,849 dogs.

    Science.gov (United States)

    Hezzell, M J; Dennis, S G; Humm, K; Agee, L; Boswood, A

    2013-06-01

    To evaluate relationships between heart rate and clinical variables in healthy dogs and dogs examined at a referral hospital. Clinical data were extracted from the electronic patient records of a first opinion group (5000 healthy dogs) and a referral hospital (5849 dogs). Univariable and multi-variable general linear models were used to assess associations between heart rate and clinical characteristics. Separate multi-variable models were constructed for first opinion and referral populations. In healthy dogs, heart rate was negatively associated with bodyweight (PChihuahuas. The mean difference in heart rate between a 5 and 55 kg dog was 10.5 beats per minute. In dogs presenting to a referral hospital, heart rate was negatively associated with bodyweight (P<0.001) and the following breeds; border collie, golden retriever, Labrador retriever, springer spaniel and West Highland white terrier and positively associated with age, admitting service (emergency and critical care, emergency first opinion and cardiology) and the following breeds; Cavalier King Charles spaniel, Staffordshire bull terrier and Yorkshire terrier. Bodyweight, age, breed and disease status all influence heart rate in dogs, although these factors account for a relatively small proportion of the overall variability in heart rate. © 2013 British Small Animal Veterinary Association.

  14. Change of Diurnal Heart Rate Patterns During Pregnancy and Lactation in Dogs (Canis familiaris

    Directory of Open Access Journals (Sweden)

    Häggström J

    2003-09-01

    Full Text Available Pregnancy and lactation involve great demands on the cardiovascular system. The purpose of this study was to investigate how the heart rate and diurnal heart rate pattern change when dogs become pregnant or lactate. Five clinically healthy female beagle dogs were mated, and delivered three to seven healthy puppies. The heart rate was investigated with 24-h ECG (Holter once during anoestrus, at 3, 5, 7 and 9 weeks of pregnancy, and at week 4 postpartum (lactation. However, at 9 weeks, the ECG could not be recorded for the fully 24 h in 4 of 5 dogs, because labour started and the dogs then appeared disturbed by the recordings. The results at this date are not included in the statistical comparison. The heart rate increased progressively during pregnancy and was still elevated at 4 weeks of lactation. During late pregnancy the difference in heart rates between daytime and nighttime became smaller, but the heart rate was significantly higher in daytime in all periods. In conclusion, the increased heart rates during pregnancy and lactation reflect increased demands on the cardiovascular system and may be important to consider in clinical practice.

  15. Variation in heart rate influences the assessment of transient ischemic dilation in myocardial perfusion scintigraphy

    International Nuclear Information System (INIS)

    Leslie, William D; Levin, Daniel P; Demeter, Sandor J

    2007-01-01

    Transient arrhythmias can affect transient ischemic dilation (TID) ratios. This study was initiated to evaluate the frequency and effect of normal heart rate change on TID measures in routine clinical practice. Consecutive patients undergoing stress/rest sestamibi gated myocardial perfusion scintigraphy were studied (N = 407). Heart rate at the time of stress and rest imaging were recorded. TID ratios were analyzed in relation to absolute change in heart rate (stress minus rest) for subjects with normal perfusion and systolic function (Group 1, N = 169) and those with abnormalities in perfusion and/or function (Group 2, N = 238). In Group 1, mean TID ratio was inversely correlated with the change in heart rate (r = -0.47, P < 0.0001). For every increase of 10 BPM in heart rate change, the TID ratio decreased by approximately 0.06 (95% confidence interval 0.04–0.07). In Group 2, multiple linear regression demonstrated that the change in heart rate (beta = -0.25, P < 0.0001) and the summed difference score (beta = 0.36, P < 0.0001) were independent predictors of the TID ratio. Normal variation in heart rate between the stress and rest components of myocardial perfusion scans is common and can influence TID ratios in patients with normal and abnormal cardiac scans

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

    Science.gov (United States)

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

    1997-01-01

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

  17. Surgical volume and conversion rate in laparoscopic hysterectomy: does volume matter? A multicenter retrospective cohort study.

    Science.gov (United States)

    Keurentjes, José H M; Briët, Justine M; de Bock, Geertruida H; Mourits, Marian J E

    2018-02-01

    A multicenter, retrospective, cohort study was conducted in the Netherlands. The aim was to evaluate whether surgical volume of laparoscopic hysterectomies (LHs) performed by proven skilled gynecologists had an impact on the conversion rate from laparoscopy to laparotomy. In 14 hospitals, all LHs performed by 19 proven skilled gynecologists between 2007 and 2010 were included in the analysis. Surgical volume, conversion rate and type of conversion (reactive or strategic) were retrospectively assessed. To estimate the impact of surgical volume on the conversion rate, logistic regressions were performed. These regressions were adjusted for patient's age, Body Mass Index (BMI), ASA classification, previous abdominal surgery and the indication (malignant versus benign) for the LH. During the study period, 19 proven skilled gynecologists performed a total of 1051 LHs. Forty percent of the gynecologists performed over 20 LHs per year (median 17.3, range 5.4-49.5). Conversion to laparotomy occurred in 5.0% of all LHs (53 of 1051); 38 (3.6%) were strategic and 15 (1.4%) were reactive conversions. Performing over 20 LHs per year was significantly associated with a lower overall conversion rate (OR adjusted 0.43, 95% CI 0.24-0.77), a lower strategic conversion rate (OR adjusted 0.32, 95% CI 0.16-0.65), but not with a lower reactive conversion rate (OR adjusted 0.96, 95% CI 0.33-2.79). A higher annual surgical volume of LHs by proven skilled gynecologists is inversely related to the conversion rate to laparotomy, and results in a lower strategic conversion rate.

  18. Understanding the heterogeneity in volume overload and fluid distribution in decompensated heart failure is key to optimal volume management: role for blood volume quantitation.

    Science.gov (United States)

    Miller, Wayne L; Mullan, Brian P

    2014-06-01

    This study sought to quantitate total blood volume (TBV) in patients hospitalized for decompensated chronic heart failure (DCHF) and to determine the extent of volume overload, and the magnitude and distribution of blood volume and body water changes following diuretic therapy. The accurate assessment and management of volume overload in patients with DCHF remains problematic. TBV was measured by a radiolabeled-albumin dilution technique with intravascular volume, pre-to-post-diuretic therapy, evaluated at hospital admission and at discharge. Change in body weight in relation to quantitated TBV was used to determine interstitial volume contribution to total fluid loss. Twenty-six patients were prospectively evaluated. Two patients had normal TBV at admission. Twenty-four patients were hypervolemic with TBV (7.4 ± 1.6 liters) increased by +39 ± 22% (range, +9.5% to +107%) above the expected normal volume. With diuresis, TBV decreased marginally (+30 ± 16%). Body weight declined by 6.9 ± 5.2 kg, and fluid intake/fluid output was a net negative 8.4 ± 5.2 liters. Interstitial compartment fluid loss was calculated at 6.2 ± 4.0 liters, accounting for 85 ± 15% of the total fluid reduction. TBV analysis demonstrated a wide range in the extent of intravascular overload. Dismissal measurements revealed marginally reduced intravascular volume post-diuretic therapy despite large reductions in body weight. Mobilization of interstitial fluid to the intravascular compartment with diuresis accounted for this disparity. Intravascular volume, however, remained increased at dismissal. The extent, composition, and distribution of volume overload are highly variable in DCHF, and this variability needs to be taken into account in the approach to individualized therapy. TBV quantitation, particularly serial measurements, can facilitate informed volume management with respect to a goal of treating to euvolemia. Copyright © 2014 American College of Cardiology Foundation. Published

  19. Effect of aerobic training on heart rate recovery in patients with established heart disease; a systematic review

    NARCIS (Netherlands)

    Snoek, Johan A.; Van Berkel, Sietske; Van Meeteren, Nico; Backx, Frank J G; Daanen, Hein A M

    2013-01-01

    Background: Although a delayed decrease in heart rate during the first minute after graded exercise has been identified as a powerful predictor of overall mortality in cardiac patients, the potential to influence this risk factor by aerobic training remains to be proven. Objective: The aim was to

  20. In Vivo CT Direct Volume Rendering: A Three-Dimensional Anatomical Description of the Heart

    International Nuclear Information System (INIS)

    Cutroneo, Giuseppina; Bruschetta, Daniele; Trimarchi, Fabio; Cacciola, Alberto; Cinquegrani, Maria; Duca, Antonio; Rizzo, Giuseppina; Alati, Emanuela; Gaeta, Michele; Milardi, Demetrio

    2016-01-01

    Since cardiac anatomy continues to play an important role in the practice of medicine and in the development of medical devices, the study of the heart in three dimensions is particularly useful to understand its real structure, function and proper location in the body. This study demonstrates a fine use of direct volume rendering, processing the data set images obtained by Computed Tomography (CT) of the heart of 5 subjects with age range between 18 and 42 years (2 male, 3 female), with no history of any overt cardiac disease. The cardiac structure in CT images was first extracted from the thorax by marking manually the regions of interest on the computer, and then it was stacked to create new volumetric data. The use of a specific algorithm allowed us to observe with a good perception of depth the heart and the skeleton of the thorax at the same time. Besides, in all examined subjects, it was possible to depict its structure and its position within the body and to study the integrity of papillary muscles, the fibrous tissue of cardiac valve and chordae tendineae and the course of coronary arteries. Our results demonstrated that one of the greatest advantages of algorithmic modifications of direct volume rendering parameters is that this method provides much necessary information in a single radiologic study. It implies a better accuracy in the study of the heart, being complementary to other diagnostic methods and facilitating the therapeutic plans

  1. Heart Rate and Energy Expenditure in Division I Field Hockey Players During Competitive Play.

    Science.gov (United States)

    Sell, Katie M; Ledesma, Allison B

    2016-08-01

    Sell, KM and Ledesma, AB. Heart rate and energy expenditure in Division I field hockey players during competitive play. J Strength Cond Res 30(8): 2122-2128, 2016-The purpose of this study was to quantify energy expenditure and heart rate data for Division I female field hockey players during competitive play. Ten female Division I collegiate field hockey athletes (19.8 ± 1.6 years; 166.4 ± 6.1 cm; 58.2 ± 5.3 kg) completed the Yo-Yo intermittent endurance test to determine maximal heart rate. One week later, all subjects wore a heart rate monitor during a series of 3 matches in an off-season competition. Average heart rate (AvHR), average percentage of maximal heart rate (AvHR%), peak exercise heart rate (PExHR), and percentage of maximal heart rate (PExHR%), time spent in each of the predetermined heart rate zones, and caloric expenditure per minute of exercise (kcalM) were determined for all players. Differences between positions (backs, midfielders, and forwards) were assessed. No significant differences in AvHR, AvHR%, PExHR, PExHR%, and %TM were observed between playing positions. The AvHR% and PExHR% for each position fell into zones 4 (77-93% HRmax) and 5 (>93% HRmax), respectively, and significantly more time was spent in zone 4 compared with zones 1, 2, 3, and 5 across all players (p ≤ 0.05). The kcalM reflected very heavy intensity exercise. The results of this study will contribute toward understanding the sport-specific physiological demands of women's field hockey and has specific implications for the duration and schedule of training regimens.

  2. Reduced heart rate variability in social anxiety disorder: associations with gender and symptom severity.

    Directory of Open Access Journals (Sweden)

    Gail A Alvares

    Full Text Available BACKGROUND: Polyvagal theory emphasizes that autonomic nervous system functioning plays a key role in social behavior and emotion. The theory predicts that psychiatric disorders of social dysfunction are associated with reduced heart rate variability, an index of autonomic control, as well as social inhibition and avoidance. The purpose of this study was to examine whether heart rate variability was reduced in treatment-seeking patients diagnosed with social anxiety disorder, a disorder characterized by social fear and avoidance. METHODS: Social anxiety patients (n = 53 were recruited prior to receiving psychological therapy. Healthy volunteers were recruited through the University of Sydney and the general community and were matched by gender and age (n = 53. Heart rate variability was assessed during a five-minute recording at rest, with participants completing a range of self-report clinical symptom measures. RESULTS: Compared to controls, participants with social anxiety exhibited significant reductions across a number of heart rate variability measures. Reductions in heart rate variability were observed in females with social anxiety, compared to female controls, and in patients taking psychotropic medication compared to non-medicated patients. Finally, within the clinical group, we observed significant associations between reduced heart rate variability and increased social interaction anxiety, psychological distress, and harmful alcohol use. CONCLUSIONS: The results of this study confirm that social anxiety disorder is associated with reduced heart rate variability. Resting state heart rate variability may therefore be considered a marker for social approach-related motivation and capacity for social engagement. Additionally, heart rate variability may provide a useful biomarker to explain underlying difficulties with social approach, impaired stress regulation, and behavioral inhibition, especially in disorders associated with

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

    Science.gov (United States)

    Yoshida, Yutaka; Yokoyama, Kiyoko; Ishii, Naohiro

    It is necessary to monitor the daily health condition for preventing stress syndrome. In this study, it was proposed the method assessing the mental and physiological condition, such as the work stress or the relaxation, using heart rate variability at real time and continuously. The instantanuous heart rate (HR), and the ratio of the number of extreme points (NEP) and the number of heart beats were calculated for assessing mental and physiological condition. In this method, 20 beats heart rate were used to calculate these indexes. These were calculated in one beat interval. Three conditions, which are sitting rest, performing mental arithmetic and watching relaxation movie, were assessed using our proposed algorithm. The assessment accuracies were 71.9% and 55.8%, when performing mental arithmetic and watching relaxation movie respectively. In this method, the mental and physiological condition was assessed using only 20 regressive heart beats, so this method is considered as the real time assessment method.

  4. Nonlinear analysis of heart rate variability in patients with eating disorders

    NARCIS (Netherlands)

    Vigo, Daniel E.; Castro, Mariana N.; Dorpinghaus, Andrea; Weidema, Hylke; Cardinali, Daniel P.; Siri, Leonardo Nicola; Rovira, Bernardo; Fahrer, Rodolfo D.; Nogues, Martin; Leiguarda, Ramon C.; Guinjoan, Salvador M.

    2008-01-01

    Patients with anorexia nervosa or bulimia nervosa often have signs of autonomic dysfunction potentially deleterious to the heart. The aim of this study was to ascertain the nonlinear properties of heart rate variability in patients with eating disorders. A group of 33 women with eating disorders (14

  5. Smart pillow for heart-rate monitoring using a fiber optic sensor

    Science.gov (United States)

    Chen, Zhihao; Teo, Ju Teng; Ng, Soon Huat; Yim, Huiqing

    2011-03-01

    In this paper, we propose and demonstrate a new method to monitor heart rate using fiber optic microbending based sensor for in-bed non-intrusive monitoring. The sensing system consists of transmitter, receiver, sensor mat, National Instrument (NI) data acquisition (DAQ) card and a computer for signal processing. The sensor mat is embedded inside a commercial pillow. The heart rate measurement system shows an accuracy of +/-2 beats, which has been successfully demonstrated in a field trial. The key technological advantage of our system is its ability to measure heart rate with no preparation and minimal compliance by the patient.

  6. GLP-1 receptor stimulation depresses heart rate variability and inhibits neurotransmission to cardiac vagal neurons.

    Science.gov (United States)

    Griffioen, Kathleen J; Wan, Ruiqian; Okun, Eitan; Wang, Xin; Lovett-Barr, Mary Rachael; Li, Yazhou; Mughal, Mohamed R; Mendelowitz, David; Mattson, Mark P

    2011-01-01

    glucagon-like peptide 1 (GLP-1) is an incretin hormone released from the gut in response to food intake. Whereas GLP-1 acts in the periphery to inhibit glucagon secretion and stimulate insulin release, it also acts in the central nervous system to mediate autonomic control of feeding, body temperature, and cardiovascular function. Because of its role as an incretin hormone, GLP-1 receptor analogs are used as a treatment for type 2 diabetes. Central or peripheral administration of GLP-1 increases blood pressure and heart rate, possibly by activating brainstem autonomic nuclei and increasing vagus nerve activity. However, the mechanism(s) by which GLP-1 receptor stimulation affects cardiovascular function are unknown. We used the long-lasting GLP-1 receptor agonist Exendin-4 (Ex-4) to test the hypothesis that GLP-1 signalling modulates central parasympathetic control of heart rate. using a telemetry system, we assessed heart rate in mice during central Ex-4 administration. Heart rate was increased by both acute and chronic central Ex-4 administration. Spectral analysis indicated that the high frequency and low frequency powers of heart rate variability were diminished by Ex-4 treatment. Finally, Ex-4 decreased both excitatory glutamatergic and inhibitory glycinergic neurotransmission to preganglionic parasympathetic cardiac vagal neurons. these data suggest that central GLP-1 receptor stimulation diminishes parasympathetic modulation of the heart thereby increasing heart rate.

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

    International Nuclear Information System (INIS)

    Van Drongelen, Wim; Williams, Amber L; Lasky, Robert E

    2009-01-01

    Certain types of biomedical processes such as the heart rate generator can be considered as signals that are sampled by the occurring events, i.e. QRS complexes. This sampling property generates problems for the evaluation of spectral parameters of such signals. First, the irregular occurrence of heart beats creates an unevenly sampled data set which must either be pre-processed (e.g. by using trace binning or interpolation) prior to spectral analysis, or analyzed with specialized methods (e.g. Lomb's algorithm). Second, the average occurrence of events determines the Nyquist limit for the sampled time series. Here we evaluate different types of spectral analysis of recordings of neonatal heart rate. Coupling between respiration and heart rate and the detection of heart rate itself are emphasized. We examine both standard and data adaptive frequency bands of heart rate signals generated by models of coupled oscillators and recorded data sets from neonates. We find that an important spectral artifact occurs due to a mirror effect around the Nyquist limit of half the average heart rate. Further we conclude that the presence of respiratory coupling can only be detected under low noise conditions and if a data-adaptive respiratory band is used

  8. 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

    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 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...... field observations. although a few breath-holds of over 40 s were recorded. The mean percentage time spent submerged was 89 +/- 0.4%. Relative to similarly-sized terrestrial mammals, the respiratory frequency was low (4.9 +/- 0.19 breaths min(-1)) but with high tidal volumes (1.1 +/- 0.01 l), enabling...

  9. Heart rate turbulence after ventricular premature beats in healthy Doberman pinschers and those with dilated cardiomyopathy.

    Science.gov (United States)

    Harris, J D; Little, C J L; Dennis, J M; Patteson, M W

    2017-10-01

    To describe the measurement of heart rate turbulence (HRT) after ventricular premature beats and compare HRT in healthy Doberman pinschers and those with dilated cardiomyopathy (DCM), with and without congestive heart failure (CHF). Sixty-five client-owned Dobermans: 20 healthy (NORMAL), 31 with preclinical DCM and 14 with DCM and CHF (DCM + CHF). A retrospective study of data retrieved from clinical records and ambulatory ECG (Holter) archives, including data collected previously for a large-scale prospective study of Dobermans with preclinical DCM. Holter data were reanalysed quantitatively, including conventional time-domain heart rate variability and the HRT parameters turbulence onset and turbulence slope. Heart rate turbulence could be measured in 58/65 dogs. Six Holter recordings had inadequate ventricular premature contractions (VPCs) and one exhibited VPCs too similar to sinus morphology. Heart rate turbulence parameter, turbulence onset, was significantly reduced in DCM dogs, whereas conventional heart rate variability measures were not. Heart rate variability and HRT markers were reduced in DCM + CHF dogs as expected. Heart rate turbulence can be measured from the majority of good quality standard canine 24-hour Holter recordings with >5 VPCs. Turbulence onset is significantly reduced in Dobermans with preclinical DCM which indicates vagal withdrawal early in the course of disease. Heart rate turbulence is a powerful prognostic indicator in human cardiac disease which can be measured from standard 24-hour ambulatory ECG (Holter) recordings using appropriate computer software. Further studies are warranted to assess whether HRT may be of prognostic value in dogs with preclinical DCM and in other canine cardiac disease. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. 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.

  11. FURTHER STUDIES ON THE VARIATION OF SPRAY DEPOSITS IN VINEYARDS WITH AIRFLOW RATE AND VOLUME RATE

    Directory of Open Access Journals (Sweden)

    Emanuele Cerruto

    2007-03-01

    Full Text Available The present research, continuing that reported in [2], deals with the spray application subject, so to investigate as volume rate and airflow rate, forward speed being equal, affect the foliar deposition in an espalier vineyard. Experimental trials were carried out by means of an air assisted towed sprayer, equipped with “Albuz ATR” nozzles. To take into account the influence of the development of the trees, the field trials were replicated in two phenological stages with an interval of about one month: “Inflorescences fully developed” (stage 1 and “Beginning of berry touch” (stage 2. A full factorial experiment was carried out for each growth stage, with two airflow rates (3.9 and 7.5 m3/s, three volume rates (103, 216, and 276 L/ha in the first growth stage and 154, 330 and 432 L/ha in the second growth stage, and four replicates, arranged according to a randomised complete block design. Working pressure (1.2 MPa and forward speed (1.4 m/s were kept unchanged for all the trials. The foliar deposition was measured by means of a spectrophotometric technique. The leaves were sampled on two depth layers and two or three heights, according to the trees’ development. The results showed that volume rate did not significantly influence the mean foliar deposition in both the two growth stages, while the highest deposits were obtained with the lowest airflow rate. The airflow rate × volume rate interaction, though not statistically significant, showed that low volume rates together with high airflow rates, result in a noticeable reduction in foliar deposition (29% with respect the grand mean, due to an increase of the spry drift, especially at the first growth stage, when the foliar development is little. These second tests, unlike those described in [2], did not show any positive influence of the airflow rate on the foliar deposition in the inner part of the canopy, so further investigations could be necessary to better understand the

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

    Science.gov (United States)

    Hegde, Shantala; Kumar, Prashanth S.; Rai, Pratyush; Mathur, Gyanesh N.; Varadan, Vijay K.

    2012-04-01

    Music is a powerful elicitor of emotions. Emotions evoked by music, through autonomic correlates have been shown to cause significant modulation of parameters like heart rate and blood pressure. Consequently, Heart Rate Variability (HRV) analysis can be a powerful tool to explore evidence based therapeutic functions of music and conduct empirical studies on effect of musical emotion on heart function. However, there are limitations with current studies. HRV analysis has produced variable results to different emotions evoked via music, owing to variability in the methodology and the nature of music chosen. Therefore, a pragmatic understanding of HRV correlates of musical emotion in individuals listening to specifically chosen music whilst carrying out day to day routine activities is needed. In the present study, we aim to study HRV as a single case study, using an e-bra with nano-sensors to record heart rate in real time. The e-bra developed previously, has several salient features that make it conducive for this study- fully integrated garment, dry electrodes for easy use and unrestricted mobility. The study considers two experimental conditions:- First, HRV will be recorded when there is no music in the background and second, when music chosen by the researcher and by the subject is playing in the background.

  13. Effects of Orthostatism and Hemodialysis on Mean Heart Period and Fractal Heart Rate Properties of Chronic Renal Failure Patients.

    Science.gov (United States)

    Echeverría, Juan C; Infante, Oscar; Pérez-Grovas, Héctor; González, Hortensia; José, Marco V; Lerma, Claudia

    2017-11-01

    The aim of this work was to evaluate the short-term fractal index (α 1 ) of heart rate variability (HRV) in chronic renal failure (CRF) patients by identifying the effects of orthostatism and hemodialysis (HD), and by evaluating the correlation between α 1 and the mean RR interval from sinus beats (meanNN). HRV time series were derived from ECG data of 19 CRF patients and 20 age-matched healthy subjects obtained at supine and orthostatic positions (lasting 5 min each). Data from CRF patients were collected before and after HD. α 1 was calculated from each time series and compared by analysis of variance. Pearson's correlations between meanNN and α 1 were calculated using the data from both positions by considering three groups: healthy subjects, CRF before HD and CRF after HD. At supine position, α 1 of CRF patients after HD (1.17 ± 0.30) was larger (P renal disease condition in itself. In conclusion, as in healthy subjects, α 1 of CRF patients correlates with meanNN after HD (indicating a more irregular-like HRV behavior at slower heart rates). This suggests that CRF patients with stable blood pressure preserve a regulatory adaptability despite a shifted setting point of the heart period (i.e., higher heart rate) in comparison with healthy subjects. © 2017 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  14. Eleven fetal echocardiographic planes using 4-dimensional ultrasound with spatio-temporal image correlation (STIC): a logical approach to fetal heart volume analysis.

    Science.gov (United States)

    Jantarasaengaram, Surasak; Vairojanavong, Kittipong

    2010-09-15

    Theoretically, a cross-sectional image of any cardiac planes can be obtained from a STIC fetal heart volume dataset. We described a method to display 11 fetal echocardiographic planes from STIC volumes. Fetal heart volume datasets were acquired by transverse acquisition from 200 normal fetuses at 15 to 40 weeks of gestation. Analysis of the volume datasets using the described technique to display 11 echocardiographic planes in the multiplanar display mode were performed offline. Volume datasets from 18 fetuses were excluded due to poor image resolution. The mean visualization rates for all echocardiographic planes at 15-17, 18-22, 23-27, 28-32 and 33-40 weeks of gestation fetuses were 85.6% (range 45.2-96.8%, N = 31), 92.9% (range 64.0-100%, N = 64), 93.4% (range 51.4-100%, N = 37), 88.7%(range 54.5-100%, N = 33) and 81.8% (range 23.5-100%, N = 17) respectively. Overall, the applied technique can favorably display the pertinent echocardiographic planes. Description of the presented method provides a logical approach to explore the fetal heart volumes.

  15. Heart rate, blood pressure and repolarization effects of an energy drink as compared to coffee.

    Science.gov (United States)

    Brothers, R Matthew; Christmas, Kevin M; Patik, Jordan C; Bhella, Paul S

    2017-11-01

    The goal of this study was to investigate the impact of energy drinks on haemodynamic and cardiac physiology. Comparisons were made to coffee as well as water consumption. In Protocol #1 the caffeine content was normalized to body weight to represent a controlled environment. Heart rate, blood pressure and cardiac QTc interval were assessed in 15 participants, on 4 days, prior to and for 6·5 h postconsumption of (i) energy drink (2 mg caffeine per kg body weight; low dose), (ii) energy drink (3 mg caffeine per kg body weight; medium dose), (iii) coffee (2 mg caffeine per kg body weight) and (iv) 250 ml water. In Protocol #2, the beverages were consumed in volumes that they are purchased to represent real-life conditions. The aforementioned measurements were repeated in 15 participants following (i) 1 16 oz can of energy drink (16 oz Monster), (ii) 1 24 oz can of energy drink (24 oz Monster), (iii) 1 packet of Keurig K-Cup Starbucks coffee (coffee) and (iv) 250 ml water. The order of the beverages was performed in a randomized double-blinded fashion. For both protocols, QTc interval, heart rate and systolic blood pressure were unchanged in any condition (P>0·05). Diastolic blood pressure and mean blood pressure were slightly elevated in Protocol #1 (P0·05). These findings suggest that acute consumption of these commonly consumed beverages has no negative effect on cardiac QTc interval. © 2016 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

  16. Blood pressure and heart rate variability analysis of orthostatic challenge in normal human pregnancies.

    Science.gov (United States)

    Heiskanen, Nonna; Saarelainen, Heli; Valtonen, Pirjo; Lyyra-Laitinen, Tiina; Laitinen, Tomi; Vanninen, Esko; Heinonen, Seppo

    2008-11-01

    The aim of the present study was to evaluate pregnancy-related changes in autonomic regulatory functions in healthy subjects. We studied cardiovascular autonomic responses to head-up tilt (HUT) in 28 pregnant women during the third trimester of pregnancy and 3 months after parturition. The maternal ECG and non-invasive beat-to-beat blood pressure were recorded in the horizontal position (left-lateral position) and during HUT in the upright position. Stroke volume was assessed from blood pressure signal by using the arterial pulse contour method. Heart rate variability (HRV) was analysed in frequency domain, and baroreflex sensitivity by the cross-spectral and the sequence methods. In the horizontal position, all frequency components of HRV were lower during pregnancy than 3 months after parturition (P pregnancy had no influence on normalized low frequency and high frequency powers. During pregnancy haemodynamics was well balanced with only minor changes in response to postural change while haemodynamic responses to HUT were more remarkable after parturition. In pregnant women HRV and especially its very low frequency component increased in response to HUT, whereas at 3 months after parturition the direction of these changes was opposite. Parasympathetic deactivation towards term is likely to contribute to increased heart rate and cardiac output at rest, whereas restored sympathetic modulation with modest responses may contribute stable peripheral resistance and sufficient placental blood supply under stimulated conditions. It is important to understand cardiovascular autonomic nervous system and haemodynamic control in normal pregnancy before being able to judge whether they are dysregulated in complicated pregnancies.

  17. Effects of breathing patterns and light exercise on linear and nonlinear heart rate variability.

    Science.gov (United States)

    Weippert, Matthias; Behrens, Kristin; Rieger, Annika; Kumar, Mohit; Behrens, Martin

    2015-08-01

    Despite their use in cardiac risk stratification, the physiological meaning of nonlinear heart rate variability (HRV) measures is not well understood. The aim of this study was to elucidate effects of breathing frequency, tidal volume, and light exercise on nonlinear HRV and to determine associations with traditional HRV indices. R-R intervals, blood pressure, minute ventilation, breathing frequency, and respiratory gas concentrations were measured in 24 healthy male volunteers during 7 conditions: voluntary breathing at rest, and metronome guided breathing (0.1, 0.2 and 0.4 Hz) during rest, and cycling, respectively. The effect of physical load was significant for heart rate (HR; p < 0.001) and traditional HRV indices SDNN, RMSSD, lnLFP, and lnHFP (p < 0.01 for all). It approached significance for sample entropy (SampEn) and correlation dimension (D2) (p < 0.1 for both), while HRV detrended fluctuation analysis (DFA) measures DFAα1 and DFAα2 were not affected by load condition. Breathing did not affect HR but affected all traditional HRV measures. D2 was not affected by breathing; DFAα1 was moderately affected by breathing; and DFAα2, approximate entropy (ApEn), and SampEn were strongly affected by breathing. DFAα1 was strongly increased, whereas DFAα2, ApEn, and SampEn were decreased by slow breathing. No interaction effect of load and breathing pattern was evident. Correlations to traditional HRV indices were modest (r from -0.14 to -0.67, p < 0.05 to <0.01). In conclusion, while light exercise does not significantly affect short-time HRV nonlinear indices, respiratory activity has to be considered as a potential contributor at rest and during light dynamic exercise.

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

    International Nuclear Information System (INIS)

    Nordrehaug, J.E.; Danielsen, R.; Vik-Mo, H.

    1989-01-01

    The effects of heart rate on the myocardial uptake and clearance of 201 Tl were studied prospectively in seven healthy men, mean age 43 +/- 7 (s.d.) yr. Initial and delayed (3 hr) thallium images were obtained in three views after three bicycle exercise tests: to maximal, 80% and 60% of predicted maximal heart rate. The mean of three views initial myocardial 201 Tl uptake was higher at maximal than at both 80% and 60% of predicted maximal heart rate, being 81% (p less than 0.01) and 60% (p less than 0.01) of maximal activity, respectively. The myocardial activity in the delayed images was identical. There was a linear relationship between heart rate and the initial myocardial activity, r = 0.86 (p less than 0.001). The mean (range) 201 Tl clearance was 58% (51-65), 47% (34-56), and 34% (22-49) (all differences p less than 0.01), respectively. Concordance among the three individual views in estimating clearance was best for the highest exercise level. There was a linear relationship between heart rate and clearance, r = 0.80 (p less than 0.001). Clearance was altered by only 1.67 x 10%/heart bpm (0.024 hr/heart beat). Clearance in the liver, spleen and lungs increased at submaximal exercise levels. Thus, a linear relationship between heart rate and clearance is the result of changes in the initial exercise myocardial 201 Tl activity. Submaximal exercise may reduce reproducibility of clearance estimation, and the change of myocardial clearance with heart rate seems less than previously suggested

  19. EFFECT OF FUROSEMIDE AND TORASEMIDE ON HEART RATE VARIABILITY AND VENTRICULAR RHYTHM DISORDERS IN PATIENTS WITH CHRONIC HEART FAILURE COMPLICATING ISCHEMIC HEART DISEASE: COMPARATIVE NONRANDOMIZED STUDY

    Directory of Open Access Journals (Sweden)

    H. H. Shugushev

    2010-01-01

    Full Text Available Aim. To study effect of diuretic therapy with furosemide and torasemide on heart rate variability (HRV and frequency of ventriclar rhythm disorders in patients with chronic heart failure (CHF complicating ischemic heart disease (IHD.Material and methods. Patients (n=107 with CHF III-IV functional class (NYHA complicating IHD were examined. The first group of patients received furosemide, 20-60 mg QD (n=52, the second group received torasemide, 5-20 mg QD (n=55. Analysis of heart rhythm disorders and the basic HRV indicators was performed by ECG 10-minute recordings initially and after 10 days of therapy.Results. Decrease in time and spectral HRV parameters and increase in daily number of ventricular extrasystoles was found in furosemide treated patients. Improvement of HRV parameters and reduction of daily number of ventricular rhythm disorders was found torasemide treated patients.Conclusion. Torasemide therapy improves an autonomic regulation of heart rhythm and leads to the reduction of ventricular heart rhythm disorders in patients with CHF complicating IHD.

  20. A novel heart rate control model provides insights linking LF-HRV behavior to the open-loop gain.

    Science.gov (United States)

    Dvir, Hila; Bobrovsky, Ben Zion; Gabbay, Uri

    2013-09-20

    Low-frequency heart rate variability (LF-HRV) at rest has already been successfully modeled as self-sustained oscillations in a nonlinear control loop, but these models fail to simulate LF-HRV decreases either during aerobic exercise or in heart failure patients. Following control engineering practices, we assume the existence of a biological excitation (dither) within the heart rate control loop that softens the nonlinearity and studied LF-HRV behavior in a dither-embedded model. We adopted the Ottesen model with some revisions and induced a dither of high-frequency stochastic perturbations. We simulated scenarios of a healthy subject at rest and during aerobic exercise (by decreasing peripheral vascular resistance) and a heart failure patient (by decreasing stroke volume). The simulations resembled physiological LF-HRV behavior, i.e., LF-HRV decreased during aerobic exercise and in the heart failure patient. The simulations exhibited LF-HRV dependency on the open-loop gain, which is related to the product of the feedback gain and the feed forward gain. We are the first to demonstrate that LF-HRV may be dependent on the open-loop gain. Accordingly, reduced open-loop gain results in decreased LF-HRV, and vice versa. Our findings explain a well-known but unexplained observed phenomenon of reduced LF-HRV both in heart failure patients and in healthy subjects performing aerobic exercise. These findings have implications on how changes in LF-HRV can be interpreted physiologically, a necessary step towards the clinical utilization of LF-HRV. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  1. The modulatory effects of noradrenaline on vagal control of heart rate in the dogfish, Squalus acanthias.

    Science.gov (United States)

    Agnisola, Claudio; Randall, David J; Taylor, Edwin W

    2003-01-01

    The possible interactions between inhibitory vagal control of the heart and circulating levels of catecholamines in dogfish (Squalus acanthias) were studied using an in situ preparation of the heart, which retained intact its innervation from centrally cut vagus nerves. The response to peripheral vagal stimulation typically consisted of an initial cardiac arrest, followed by an escape beat, leading to renewed beating at a mean heart rate lower than the prestimulation rate (partial recovery). Cessation of vagal stimulation led to a transient increase in heart rate, above the prestimulation rate. This whole response was completely abolished by 10(-4) M atropine (a muscarinic cholinergic antagonist). The degree of vagal inhibition was evaluated in terms of both the initial, maximal cardiac interval and the mean heart rate during partial recovery, both expressed as a percentage of the prestimulation heart rate. The mean prestimulation heart rate of this preparation (36+/-4 beats min(-1)) was not affected by noradrenaline but was significantly reduced by 10(-4) M nadolol (a beta-adrenergic receptor antagonist), suggesting the existence of a resting adrenergic tone arising from endogenous catecholamines. The degree of vagal inhibition of heart rate varied with the rate of stimulation and was increased by the presence of 10(-8) M noradrenaline (the normal in vivo level in routinely active fish), while 10(-7) M noradrenaline (the in vivo level measured in disturbed or deeply hypoxic fish) reduced the cardiac response to vagal stimulation. In the presence of 10(-7) M noradrenaline, 10(-4) M nadolol further reduced the vagal response, while 10(-4) M nadolol + 10(-4) M phentolamine had no effect, indicating a complex interaction between adrenoreceptors, possibly involving presynaptic modulation of vagal inhibition.

  2. Changes of heart rate variability and baroreflex sensitivity in patients soon after orthotopic heart transplantation

    Czech Academy of Sciences Publication Activity Database

    Fráňa, P.; Kára, T.; Souček, M.; Halámek, Josef; Řiháček, I.; Orban, O.; Toman, J.; Bartosikova, L.; Nečas, J.; Dzurova, J.

    2002-01-01

    Roč. 20, č. 4 (2002), s. S293 ISSN 0263-6352. [Scientific meeting of the international society of hypertension - european meeting on hypertension. 23.06.2002-27.06.2002, Praha] R&D Projects: GA ČR GA102/00/1262; GA ČR GA102/02/1339 Institutional research plan: CEZ:AV0Z2065902 Keywords : baroreflex * heart transplantation * ANS Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  3. Effect of Cardiac Rehabilitation on Heart Rate and Functional Capacity in Patients After Myocardial Infarction

    Directory of Open Access Journals (Sweden)

    Mandana Parvand

    2016-09-01

    Discussion: Cardiac rehabilitation can increase the performance of blood circulation and uptake of oxygen in body. Due to these changes, there was a significant increase in the functional capacity and an insignificant reduction in the heart rate.

  4. Factors that affect the variability in heart rate during endoscopic retrograde cholangiopancreatography

    DEFF Research Database (Denmark)

    Christensen, Merete; Reinert, Rebekka; Rasmussen, Verner

    2002-01-01

    OBJECTIVE: To find out if drugs, position, and endoscopic manipulation during endoscopic retrograde cholangiopancreatography (ERCP) influence the changes in the variability of heart rate. DESIGN: Single-blind randomised trial. SUBJECTS: 10 volunteers given butyscopolamine, glucagon, or saline...

  5. Time-Frequency Analysis of Terahertz Radar Signals for Rapid Heart and Breath Rate Detection

    National Research Council Canada - National Science Library

    Massar, Melody L

    2008-01-01

    We develop new time-frequency analytic techniques which facilitate the detection of a person's heart and breath rates from the Doppler shift the movement of their body induces in a terahertz radar signal...

  6. Facial electromyogram and heart-rate correlates of a paradoxical attitude change to antinuclear war information

    International Nuclear Information System (INIS)

    Vigne, J.J.; Dale, J.A.; Klions, H.L.

    1988-01-01

    The effects of film images versus film descriptions of the effects of nuclear explosions (versus a no-film control) on corrugator muscle tension, heart rate, attitude and mood were investigated. The last 5 min. of the images were associated with more corrugator tension for that condition when compared to the last 5 min. of the description condition. The groups did not differ in heart rate but women in both groups showed an increase in heart rate whereas men in both groups showed a decrease in heart rate. Film groups did not differ in their significant increases in anxiety, hostility, and depression on the Multiple Adjective Affect Checklist. On the pretest there was no significant correlation between scores on Betts' Questionnaire Upon Mental Imagery and scores on Goldenring and Doctor's index of concern for nuclear war. The vivid-image film group showed a decrease in concern for nuclear war when compared to the descriptive film group and the no-film control

  7. New descriptors of T-wave morphology are independent of heart rate

    DEFF Research Database (Denmark)

    Andersen, Mads Peter; Xue, Joel Q; Graff, Claus

    2008-01-01

    from daytime Holter recordings. Duration parameters (QT, ToTe, TpTe, and others), a number of basic T-wave morphology parameters (amplitude, area, and others) as well as advanced morphology descriptors (asymmetry, flatness, and others) were measured automatically. Heart rate dependence was examined...... by means of analysis of covariance. The results showed clear heart rate dependence for the QT interval (R(2) = 0.53-0.57) and a moderate degree of heart rate dependence for the basic morphology parameters (amplitude, area, and others) (R(2) = 0.17-0.42). Both the advanced T-wave descriptors (asymmetry......T-wave morphology descriptors are sensitive to drug-induced changes and may be a useful addition to the QT interval in cardiac safety trials. Intrasubject heart rate dependence of T-wave morphology was investigated in a sample of 39 healthy individuals. Ten-second electrocardiograms were obtained...

  8. Dogs with macroadenomas have lower body temperature and heart rate than dogs with microadenomas.

    Science.gov (United States)

    Benchekroun, Ghita; Desquilbet, Loic; Herrtage, Michael E; Jeffery, Nick D; Rosenberg, Dan; Granger, Nicolas

    2017-09-01

    Pituitary macroadenomas compress the hypothalamus, which partly regulates heart rate and body temperature. The aim of this study was to investigate whether heart rate and/or body temperature could aid in clinically differentiating dogs with macroadenomas from dogs with microadenomas (i.e. small non-compressive pituitary mass). Two groups of dogs diagnosed with pituitary-dependent hyperadrenocorticism (i.e. Cushing's disease) were included. Heart rate and body temperature were collected on initial presentation before any procedure. Dogs with macroadenoma had a significantly lower heart rate and body temperature (Pdogs with microadenoma. We suggest that the combined cut-off values of 84 beats per minutes and 38.3°C in dogs with Cushing's disease, especially with vague neurological signs (nine of 12 dogs=75%), might help to suspect the presence of a macroadenoma. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Risk Assessment of Diabetes Mellitus by Chaotic Globals to Heart Rate Variability via Six Power Spectra

    Directory of Open Access Journals (Sweden)

    Garner David M.

    2017-09-01

    Full Text Available Background: The priniciple objective here is to analyze cardiovascular dynamics in diabetic subjects by actions related to heart rate variability (HRV. The correlation of chaotic globals is vital to evaluate the probability of dynamical diseases.

  10. Effect of pre operative heart rate on post spinal hypotension in obsteric patients

    International Nuclear Information System (INIS)

    Khan, S.; Zahoor, M.U.; Zaid, A.Y.; Buland, K.

    2010-01-01

    The purpose of the study was to determine the association between of preoperative heart rate and post spinal hypotension in women undergoing cesarean section, Two hundred patients undergoing caesarean were included in the study selected on non probability convenience sampling technique, The patients were divided into two groups depending upon their pre operative heart rate. Spinal anesthesia was administered and number of patients developing hypotension was noted. Among 200 patients, who were included in the study; 112 were placed in group A and 88 were placed in group B depending on mean heart rate of 90 beats per minute or less or 91 beats per minute or more respectively. In group A 14 (11.86%) patients developed hypotension where as in group B 28 (31,82%) patients developed hypotension. Pre operative heart rate is significantly associated with post spinal hypotension in obstetric patients undergoing cesarean section. (author)

  11. Heart rate variability, sleep, and the early detection of post-traumatic stress disorder

    NARCIS (Netherlands)

    van Boxtel, Geert J.M.; Cluitmans, Pierre J.M.; Raymann, Roy J.E.M.; Ouwerkerk, Martin; Denissen, Ad J.M.; Dekker, Marian K.J.; Sitskoorn, Margriet M.; Vermetten, E.; Germain, A.; Neylan, T.C.

    2017-01-01

    Measures of heart rate variability (HRV) are sensitive indices of autonomic nervous system functioning, capable of distinguishing activity of its two constituent branches, the sympathetic and parasympathetic nervous systems. As such, these measures are possibly useful as early markers of

  12. Neuroendocrine and renal effects of intravascular volume expansion in compensated heart failure

    DEFF Research Database (Denmark)

    Gabrielsen, A; Bie, P; Holstein-Rathlou, N H

    2001-01-01

    To examine if the neuroendocrine link between volume sensing and renal function is preserved in compensated chronic heart failure [HF, ejection fraction 0.29 +/- 0.03 (mean +/- SE)] we tested the hypothesis that intravascular and central blood volume expansion by 3 h of water immersion (WI) elicits...... sustained angiotensin-converting enzyme inhibitor therapy, n = 9) absolute and fractional sodium excretion increased (P Renal free water clearance increased during WI in control subjects but not in HF......, albeit plasma vasopressin concentrations were similar in the two groups. In conclusion, the neuroendocrine link between volume sensing and renal sodium excretion is preserved in compensated HF. The natriuresis of WI is, however, modulated by the prevailing ANG II and Aldo concentrations. In contrast...

  13. Evidence that BDNF regulates heart rate by a mechanism involving increased brainstem parasympathetic neuron excitability

    OpenAIRE

    Wan, Ruiqian; Weigand, Letitia A.; Bateman, Ryan; Griffioen, Kathleen; Mendelowitz, David; Mattson, Mark P.

    2014-01-01

    Autonomic control of heart rate is mediated by cardioinhibitory parasympathetic cholinergic neurons located in the brainstem and stimulatory sympathetic noradrenergic neurons. During embryonic development the survival and cholinergic phenotype of brainstem autonomic neurons is promoted by brain-derived neurotrophic factor (BDNF). We now provide evidence that BDNF regulates heart rate by a mechanism involving increased brainstem cardioinhibitory parasympathetic activity. Mice with a BDNF haplo...

  14. Estimating energy expenditure from heart rate in older adults: a case for calibration.

    Science.gov (United States)

    Schrack, Jennifer A; Zipunnikov, Vadim; Goldsmith, Jeff; Bandeen-Roche, Karen; Crainiceanu, Ciprian M; Ferrucci, Luigi

    2014-01-01

    Accurate measurement of free-living energy expenditure is vital to understanding changes in energy metabolism with aging. The efficacy of heart rate as a surrogate for energy expenditure is rooted in the assumption of a linear function between heart rate and energy expenditure, but its validity and reliability in older adults remains unclear. To assess the validity and reliability of the linear function between heart rate and energy expenditure in older adults using different levels of calibration. Heart rate and energy expenditure were assessed across five levels of exertion in 290 adults participating in the Baltimore Longitudinal Study of Aging. Correlation and random effects regression analyses assessed the linearity of the relationship between heart rate and energy expenditure and cross-validation models assessed predictive performance. Heart rate and energy expenditure were highly correlated (r=0.98) and linear regardless of age or sex. Intra-person variability was low but inter-person variability was high, with substantial heterogeneity of the random intercept (s.d. =0.372) despite similar slopes. Cross-validation models indicated individual calibration data substantially improves accuracy predictions of energy expenditure from heart rate, reducing the potential for considerable measurement bias. Although using five calibration measures provided the greatest reduction in the standard deviation of prediction errors (1.08 kcals/min), substantial improvement was also noted with two (0.75 kcals/min). These findings indicate standard regression equations may be used to make population-level inferences when estimating energy expenditure from heart rate in older adults but caution should be exercised when making inferences at the individual level without proper calibration.

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

    Science.gov (United States)

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

    2009-01-01

    Behçet's disease, a multisystemic inflammatory disorder, has been associated with a number of cardiovascular dysfunctions, including ventricular arrhythmias and sudden cardiac death. Heart-rate recovery after exercise can provide both an estimate of impaired parasympathetic tone and a prognosis in regard to all-cause and cardiovascular death. The aim of our study was to evaluate heart-rate recovery in Behçet's disease From January through July 2008, we examined at our outpatient clinic and prospectively enrolled 30 consecutive patients with Behçet's disease and 50 healthy control participants who were matched for age and sex. Basal electrocardiography, echocardiography, and treadmill exercise testing were performed in all patients and control participants. The heart-rate recovery index was calculated in the usual manner, by subtracting the 1st-minute (Rec1), 2nd-minute (Rec2), and 3rd-minute (Rec3) recovery heart rates from the maximal heart rate after exercise stress testing. Patients with Behçet's disease exhibited significantly lower heart-rate recovery numbers, compared with healthy control participants: Rec1, 24.28 ± 8.2 vs 34.4 ± 7.6, P = 0.002; Rec2, 49.28 ± 11.2 vs 57.5 ± 7.0, P < 0.05; and Rec3, 56.2 ± 12.11 vs 67.4 ± 8.7, P = 0.014. To our knowledge, this is the 1st study that shows an impaired heart-rate recovery index (indicative of reduced parasympathetic activity) among patients with Behçet's disease. Given the independent prognostic value of the heart-rate recovery index, our results may explain the increased occurrence of arrhythmias and sudden cardiac death in Behçet's patients. Therefore, this index may be clinically useful in the identification of high-risk patients. PMID:19693299

  16. Heart rate variability in normal-weight patients with polycystic ovary syndrome

    OpenAIRE

    Kilit, Celal; Kilit, T?rkan Pa?al?

    2017-01-01

    Objective: Polycystic ovary syndrome (PCOS) is an endocrine disease closely related to several risk factors of cardiovascular disease. Obese women with PCOS show altered autonomic modulation. The results of studies investigating cardiac autonomic functions of normal-weight women with PCOS are conflicting. The aim of the study was to assess the reactivity of cardiac sympathovagal balance in normal-weight women with PCOS by heart rate variability analysis. Methods: We examined the heart rate va...

  17. Design of a heart rate controller for treadmill exercise using a recurrent fuzzy neural network.

    Science.gov (United States)

    Lu, Chun-Hao; Wang, Wei-Cheng; Tai, Cheng-Chi; Chen, Tien-Chi

    2016-05-01

    In this study, we developed a computer controlled treadmill system using a recurrent fuzzy neural network heart rate controller (RFNNHRC). Treadmill speeds and inclines were controlled by corresponding control servo motors. The RFNNHRC was used to generate the control signals to automatically control treadmill speed and incline to minimize the user heart rate deviations from a preset profile. The RFNNHRC combines a fuzzy reasoning capability to accommodate uncertain information and an artificial recurrent neural network learning process that corrects for treadmill system nonlinearities and uncertainties. Treadmill speeds and inclines are controlled by the RFNNHRC to achieve minimal heart rate deviation from a pre-set profile using adjustable parameters and an on-line learning algorithm that provides robust performance against parameter variations. The on-line learning algorithm of RFNNHRC was developed and implemented using a dsPIC 30F4011 DSP. Application of the proposed control scheme to heart rate responses of runners resulted in smaller fluctuations than those produced by using proportional integra control, and treadmill speeds and inclines were smoother. The present experiments demonstrate improved heart rate tracking performance with the proposed control scheme. The RFNNHRC scheme with adjustable parameters and an on-line learning algorithm was applied to a computer controlled treadmill system with heart rate control during treadmill exercise. Novel RFNNHRC structure and controller stability analyses were introduced. The RFNNHRC were tuned using a Lyapunov function to ensure system stability. The superior heart rate control with the proposed RFNNHRC scheme was demonstrated with various pre-set heart rates. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  18. Parasympathetic neural activity accounts for the lowering of exercise heart rate at high altitude

    DEFF Research Database (Denmark)

    Boushel, Robert Christopher; Calbet, J A; Rådegran, G

    2001-01-01

    In chronic hypoxia, both heart rate (HR) and cardiac output (Q) are reduced during exercise. The role of parasympathetic neural activity in lowering HR is unresolved, and its influence on Q and oxygen transport at high altitude has never been studied.......In chronic hypoxia, both heart rate (HR) and cardiac output (Q) are reduced during exercise. The role of parasympathetic neural activity in lowering HR is unresolved, and its influence on Q and oxygen transport at high altitude has never been studied....

  19. Heart rate recovery after maximal exercise is blunted in hypertensive seniors

    Science.gov (United States)

    Best, Stuart A.; Bivens, Tiffany B.; Dean Palmer, M.; Boyd, Kara N.; Melyn Galbreath, M.; Okada, Yoshiyuki; Carrick-Ranson, Graeme; Shibata, Shigeki; Hastings, Jeffrey L.; Spencer, Matthew D.; Tarumi, Takashi; Levine, Benjamin D.; Fu, Qi

    2014-01-01

    Abnormal heart rate recovery (HRR) after maximal exercise may indicate autonomic dysfunction and is a predictor for cardiovascular mortality. HRR is attenuated with aging and in middle-age hypertensive patients, but it is unknown whether HRR is attenuated in older-age adults with hypertension. This study compared HRR among 16 unmedicated stage 1 hypertensive (HTN) participants [nine men/seven women; 68 ± 5 (SD) yr; awake ambulatory blood pressure (BP) 149 ± 10/87 ± 7 mmHg] and 16 normotensive [control (CON)] participants (nine men/seven women; 67 ± 5 yr; 122 ± 4/72 ± 5 mmHg). HR, BP, oxygen uptake (V̇o2), cardiac output (Qc), and stroke volume (SV) were measured at rest, at two steady-state work rates, and graded exercise to peak during maximal treadmill exercise. During 6 min of seated recovery, the change in HR (ΔHR) was obtained every minute and BP every 2 min. In addition, HRR and R-R interval (RRI) recovery kinetics were analyzed using a monoexponential function, and the indexes (HRRI and RRII) were calculated. Maximum V̇o2, HR, Qc, and SV responses during exercise were not different between groups. ΔHR was significantly different (P age adults, HRR is attenuated further with the presence of hypertension, which may be attributable to an impairment of autonomic function. PMID:25301897

  20. Activity and heart rate in semi-domesticated reindeer during adaptation to emergency feeding.

    Science.gov (United States)

    Nilsson, A; Ahman, B; Norberg, H; Redbo, I; Eloranta, E; Olsson, K

    2006-06-15

    Although reindeer are well adapted to limited food resources during winter, semi-domesticated reindeer are regularly fed when snow conditions are bad in order to prevent starvation. Feeding sometimes results in health problems and loss of animals. This study was made to assess if activity pattern in reindeer could be used as a tool for the reindeer herder in early detection of animals that are not adapting to feeding. The frequency of 10 behavioural categories was recorded in five groups of penned, eight-month-old, female semi-domesticated reindeer. Three reindeer per group were fitted with heart rate monitors. Lying was the most frequent behaviour, whilst there were few cases of agonistic behaviour. Heart rate varied during the day, with peaks during feeding and low heart rates in the early morning. Restricted feed intake resulted in more locomotion and seeking but less ruminating compared to feeding ad libitum. This was followed by a generally lower heart rate in reindeer in the restricted groups compared to controls. Subsequent feeding with different combinations of lichens, silage and pellets ad libitum resulted initially in significantly more of the animals lying curled up, compared to controls, combined with increased heart rates. As the experiment continued the general activity pattern, as well as the heart rate, gradually became more similar in all groups. Lying curled was the behavioural indicator most consistently affected by feed deprivation and adaptation to feeding and may thus be a useful indicator to distinguish individual reindeer that are not adjusting to feeding.

  1. Heart rate profiles and energy cost of locomotion during cross-country skiing races.

    Science.gov (United States)

    Mognoni, P; Rossi, G; Gastaldelli, F; Canclini, A; Cotelli, F

    2001-07-01

    The purpose of this study was to compare heart rate responses and speed in two cross-country skiing races, which were run by seven male and seven female subjects by using classic and free style. Heart rates and skiing velocities were analyzed over flat, uphill and downhill sections, which were run from one to three times. Heart rates were higher in uphill sections than in flat sections; a steady-state heart rate was never reached in the downhill section. When the same uphill section was repeated, the heart rate tended to increase but the speed to decrease. Oxygen uptake (VO2) was calculated from heart rate:VO2 ratio, measured during uphill walking with the aid of poles. The mean (SD) energy cost of locomotion (i.e., the ratio between net VO2 and speed) was 162.1 (9.4) ml.km(-1).kg(-1) and 147.7 (7.1) ml.km(-1).kg(-1) when male subjects ran the flat section after first downhill by using classic and free style, respectively. Females had lower values for VO2 and speed, but similar energy costs. In general, the variability of the energy cost of locomotion in skiers of a similar competitive level is of the same order as that found in uphill walking on a treadmill.

  2. Correlation of radiation dose and heart rate in dual-source computed tomography coronary angiography.

    Science.gov (United States)

    Laspas, Fotios; Tsantioti, Dimitra; Roussakis, Arkadios; Kritikos, Nikolaos; Efthimiadou, Roxani; Kehagias, Dimitrios; Andreou, John

    2011-04-01

    Computed tomography coronary angiography (CTCA) has been widely used since the introduction of 64-slice scanners and dual-source CT technology, but the relatively high radiation dose remains a major concern. To evaluate the relationship between radiation exposure and heart rate (HR), in dual-source CTCA. Data from 218 CTCA examinations, performed with a dual-source 64-slices scanner, were statistically evaluated. Effective radiation dose, expressed in mSv, was calculated as the product of the dose-length product (DLP) times a conversion coefficient for the chest (mSv = DLPx0.017). Heart rate range and mean heart rate, expressed in beats per minute (bpm) of each individual during CTCA, were also provided by the system. Statistical analysis of effective dose and heart rate data was performed by using Pearson correlation coefficient and two-sample t-test. Mean HR and effective dose were found to have a borderline positive relationship. Individuals with a mean HR >65 bpm observed to receive a statistically significant higher effective dose as compared to those with a mean HR ≤65 bpm. Moreover, a strong correlation between effective dose and variability of HR of more than 20 bpm was observed. Dual-source CT scanners are considered to have the capability to provide diagnostic examinations even with high HR and arrhythmias. However, it is desirable to keep the mean heart rate below 65 bpm and heart rate fluctuation less than 20 bpm in order to reduce the radiation exposure.

  3. Heart rate variability in infants with West syndrome

    DEFF Research Database (Denmark)

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

    2015-01-01

    -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......, when hypsarrhythmia was no longer present. RESULTS: Compared to controls, patients with WS during hypsarrhythmia had significantly lower SDNN (the standard deviation of the NN interval, i.e. the square root of variance) (19.2ms; p=0.007, Mann-Whitney's U-Test) and total power (242ms(2); p=0.044, Mann...

  4. Aerobic exercise during pregnancy and presence of fetal-maternal heart rate synchronization.

    Directory of Open Access Journals (Sweden)

    Peter Van Leeuwen

    Full Text Available It has been shown that short-term direct interaction between maternal and fetal heart rates may take place and that this interaction is affected by the rate of maternal respiration. The aim of this study was to determine the effect of maternal aerobic exercise during pregnancy on the occurrence of fetal-maternal heart rate synchronization.In 40 pregnant women at the 36th week of gestation, 21 of whom exercised regularly, we acquired 18 min. RR interval time series obtained simultaneously in the mothers and their fetuses from magnetocardiographic recordings. The time series of the two groups were examined with respect to their heart rate variability, the maternal respiratory rate and the presence of synchronization epochs as determined on the basis of synchrograms. Surrogate data were used to assess whether the occurrence of synchronization was due to chance.In the original data, we found synchronization occurred less often in pregnancies in which the mothers had exercised regularly. These subjects also displayed higher combined fetal-maternal heart rate variability and lower maternal respiratory rates. Analysis of the surrogate data showed shorter epochs of synchronization and a lack of the phase coordination found between maternal and fetal beat timing in the original data.The results suggest that fetal-maternal heart rate coupling is present but generally weak. Maternal exercise has a damping effect on its occurrence, most likely due to an increase in beat-to-beat differences, higher vagal tone and slower breathing rates.

  5. Aerobic exercise during pregnancy and presence of fetal-maternal heart rate synchronization.

    Science.gov (United States)

    Van Leeuwen, Peter; Gustafson, Kathleen M; Cysarz, Dirk; Geue, Daniel; May, Linda E; Grönemeyer, Dietrich

    2014-01-01

    It has been shown that short-term direct interaction between maternal and fetal heart rates may take place and that this interaction is affected by the rate of maternal respiration. The aim of this study was to determine the effect of maternal aerobic exercise during pregnancy on the occurrence of fetal-maternal heart rate synchronization. In 40 pregnant women at the 36th week of gestation, 21 of whom exercised regularly, we acquired 18 min. RR interval time series obtained simultaneously in the mothers and their fetuses from magnetocardiographic recordings. The time series of the two groups were examined with respect to their heart rate variability, the maternal respiratory rate and the presence of synchronization epochs as determined on the basis of synchrograms. Surrogate data were used to assess whether the occurrence of synchronization was due to chance. In the original data, we found synchronization occurred less often in pregnancies in which the mothers had exercised regularly. These subjects also displayed higher combined fetal-maternal heart rate variability and lower maternal respiratory rates. Analysis of the surrogate data showed shorter epochs of synchronization and a lack of the phase coordination found between maternal and fetal beat timing in the original data. The results suggest that fetal-maternal heart rate coupling is present but generally weak. Maternal exercise has a damping effect on its occurrence, most likely due to an increase in beat-to-beat differences, higher vagal tone and slower breathing rates.

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

    Science.gov (United States)

    Van Leeuwen, Peter; Gustafson, Kathleen M.; Cysarz, Dirk; Geue, Daniel; May, Linda E.; Grönemeyer, Dietrich

    2014-01-01

    It has been shown that short-term direct interaction between maternal and fetal heart rates may take place and that this interaction is affected by the rate of maternal respiration. The aim of this study was to determine the effect of maternal aerobic exercise during pregnancy on the occurrence of fetal-maternal heart rate synchronization. Methods In 40 pregnant women at the 36th week of gestation, 21 of whom exercised regularly, we acquired 18 min. RR interval time series obtained simultaneously in the mothers and their fetuses from magnetocardiographic recordings. The time series of the two groups were examined with respect to their heart rate variability, the maternal respiratory rate and the presence of synchronization epochs as determined on the basis of synchrograms. Surrogate data were used to assess whether the occurrence of synchronization was due to chance. Results In the original data, we found synchronization occurred less often in pregnancies in which the mothers had exercised regularly. These subjects also displayed higher combined fetal-maternal heart rate variability and lower maternal respiratory rates. Analysis of the surrogate data showed shorter epochs of synchronization and a lack of the phase coordination found between maternal and fetal beat timing in the original data. Conclusion The results suggest that fetal-maternal heart rate coupling is present but generally weak. Maternal exercise has a damping effect on its occurrence, most likely due to an increase in beat-to-beat differences, higher vagal tone and slower breathing rates. PMID:25162592

  7. Right heart ejection fraction, ventricular volumes, and left to right cardiac shunt measurements with a conventional Anger camera in congenital heart disease

    International Nuclear Information System (INIS)

    Cook, S.A.; Go, R.T.; MacIntyre, W.J.; Moodie, D.S.; Houser, T.S.; Ceimo, J.; Underwood, D.; Yiannikas, J.

    1982-01-01

    The object of this investigation was to demonstrate that a conventional Anger camera can be used for measurement of right heart ejection fraction, ventricular volumes and left to right shunts in routine clinical determinations. The automatic selection of chamber and lung regions, the recirculation subtraction of recirculation, and the filtering of the right heart ejection fraction dilution curves are all done entirely without operator intervention. Thus, this entire evaluation has been incorporated into the routine procedures of patient care

  8. The effect of orthostatic stress on multiscale entropy of heart rate and blood pressure

    International Nuclear Information System (INIS)

    Turianikova, Zuzana; Javorka, Kamil; Calkovska, Andrea; Javorka, Michal; Baumert, Mathias

    2011-01-01

    Cardiovascular control acts over multiple time scales, which introduces a significant amount of complexity to heart rate and blood pressure time series. Multiscale entropy (MSE) analysis has been developed to quantify the complexity of a time series over multiple time scales. In previous studies, MSE analyses identified impaired cardiovascular control and increased cardiovascular risk in various pathological conditions. Despite the increasing acceptance of the MSE technique in clinical research, information underpinning the involvement of the autonomic nervous system in the MSE of heart rate and blood pressure is lacking. The objective of this study is to investigate the effect of orthostatic challenge on the MSE of heart rate and blood pressure variability (HRV, BPV) and the correlation between MSE (complexity measures) and traditional linear (time and frequency domain) measures. MSE analysis of HRV and BPV was performed in 28 healthy young subjects on 1000 consecutive heart beats in the supine and standing positions. Sample entropy values were assessed on scales of 1–10. We found that MSE of heart rate and blood pressure signals is sensitive to changes in autonomic balance caused by postural change from the supine to the standing position. The effect of orthostatic challenge on heart rate and blood pressure complexity depended on the time scale under investigation. Entropy values did not correlate with the mean values of heart rate and blood pressure and showed only weak correlations with linear HRV and BPV measures. In conclusion, the MSE analysis of heart rate and blood pressure provides a sensitive tool to detect changes in autonomic balance as induced by postural change

  9. The study of alteration in left ventricular volume and pressure to volume ratio during exercise in patients with coronary heart disease

    International Nuclear Information System (INIS)

    Liu Zhonglin; Pei Zhuguo; Zang Bin

    1994-01-01

    The alterations induced by exercise in left ventricular end diastolic volume index (EDVI), end systolic volume index (ESVI) and systolic blood pressure to end systolic volume ratio (P/ESV) were studied in 15 normal subjects and 42 patients with coronary heart disease using a non-geometric count-based method and supine bicycle exercise test. Normal subjects had an increase in EDVI and a decrease in ESVI, but coronary heart disease patients had an increase in both EDVI and ESVI. The extent of increase induced by exercise in EDVI was greater in angina patients than that in normal and old myocardial infarction subjects. The P/ESV can be used to evaluate left ventricular systolic pressure-volume relationship. For the P/ESV exercise response, the sensitivity, specificity and accuracy for coronary heart disease were 95%, 93% and 95%, respectively

  10. Hekla Volcano, Iceland, in the 20th Century: Lava Volumes, Production Rates, and Effusion Rates

    Science.gov (United States)

    Pedersen, G. B. M.; Belart, J. M. C.; Magnússon, E.; Vilmundardóttir, O. K.; Kizel, F.; Sigurmundsson, F. S.; Gísladóttir, G.; Benediktsson, J. A.

    2018-02-01

    Lava flow thicknesses, volumes, and effusion rates provide essential information for understanding the behavior of eruptions and their associated deformation signals. Preeruption and posteruption elevation models were generated from historical stereo photographs to produce the lava flow thickness maps for the last five eruptions at Hekla volcano, Iceland. These results provide precise estimation of lava bulk volumes: V1947-1948 = 0.742 ± 0.138 km3, V1970 = 0.205 ± 0.012 km3, V1980-1981 = 0.169 ± 0.016 km3, V1991 = 0.241 ± 0.019 km3, and V2000 = 0.095 ± 0.005 km3 and reveal variable production rate through the 20th century. These new volumes improve the linear correlation between erupted volume and coeruption tilt change, indicating that tilt may be used to determine eruption volume. During eruptions the active vents migrate 325-480 m downhill, suggesting rough excess pressures of 8-12 MPa and that the gradient of this excess pressure increases from 0.4 to 11 Pa s-1 during the 20th century. We suggest that this is related to increased resistance along the eruptive conduit.

  11. An EEMD-PCA approach to extract heart rate, respiratory rate and respiratory activity from PPG signal.

    Science.gov (United States)

    Motin, Mohammod Abdul; Karmakar, Chandan Kumar; Palaniswami, Marimuthu

    2016-08-01

    The pulse oximeter's photoplethysmographic (PPG) signals, measure the local variations of blood volume in tissues, reflecting the peripheral pulse modulated by cardiac activity, respiration and other physiological effects. Therefore, PPG can be used to extract the vital cardiorespiratory signals like heart rate (HR), respiratory rate (RR) and respiratory activity (RA) and this will reduce the number of sensors connected to the patient's body for recording vital signs. In this paper, we propose an algorithm based on ensemble empirical mode decomposition with principal component analysis (EEMD-PCA) as a novel approach to estimate HR, RR and RA simultaneously from PPG signal. To examine the performance of the proposed algorithm, we used 45 epochs of PPG, electrocardiogram (ECG) and respiratory signal extracted from the MIMIC database (Physionet ATM data bank). The ECG and capnograph based respiratory signal were used as the ground truth and several metrics such as magnitude squared coherence (MSC), correlation coefficients (CC) and root mean square (RMS) error were used to compare the performance of EEMD-PCA algorithm with most of the existing methods in the literature. Results of EEMD-PCA based extraction of HR, RR and RA from PPG signal showed that the median RMS error (quartiles) obtained for RR was 0 (0, 0.89) breaths/min, for HR was 0.62 (0.56, 0.66) beats/min and for RA the average value of MSC and CC was 0.95 and 0.89 respectively. These results illustrated that the proposed EEMD-PCA approach is more accurate in estimating HR, RR and RA than other existing methods.

  12. Heart Rate and Oxygen Uptake Recovery and the Level of Aerobic Capacity in Mountain Bikers

    Directory of Open Access Journals (Sweden)

    Michalik Kamil

    2017-12-01

    Full Text Available Introduction. Since mountain biking involves exercise of varying intensity, competitive performance may be affected by the rate of recovery. The aim of the current study was to determine whether maximal oxygen uptake is associated with the rate of heart rate and oxygen uptake recovery in mountain bike athletes.

  13. Association between depression and heart rate variability in patients after cardiac surgery: a pilot study.

    Science.gov (United States)

    Patron, Elisabetta; Messerotti Benvenuti, Simone; Favretto, Giuseppe; Valfrè, Carlo; Bonfà, Carlotta; Gasparotto, Renata; Palomba, Daniela

    2012-07-01

    Depression is a risk factor for cardiovascular diseases. Reduced heart rate variability (HRV), which reflects altered autonomic nervous system activity, has been suggested as one of the mechanisms linking depression to cardiovascular diseases. However, the relationship between depression and HRV has not yet been investigated in patients undergone cardiac surgery. Therefore, the main aim of this study was to examine whether postoperative depression could be related to reduced HRV. Eleven patients with depression and 22 patients without depression, who had undergone cardiac surgery, were enrolled postoperatively. In all patients, HRV was derived from a four-minute blood volume pulse recording at rest. Analyses of covariance and partial correlations, while controlling for anxiety, were used to examine the associations between postoperative depression and each HRV parameter. Compared to non-depressed patients, patients with depression showed significantly lower standard deviation of N-to-N intervals (SDNN) (p=.02), root mean square successive difference of N-to-N intervals (rMSSD) (p=.001), and high-frequency power (p=.002). Partial correlation analyses showed that depression was inversely related to SDNN (r=-.49, p=.005), rMSSD (r=-.58, p=.001), and high-frequency power (r=-.41, p=.02), whereas it was unrelated to other HRV parameters (p's>.09). The current findings extend the depression-reduced HRV relationship to the patients after cardiac surgery. Also, our study suggests that postoperative depression is more likely to be associated with reduced vagal modulation on the heart than with excessive sympathetic activity. Copyright © 2012 Elsevier Inc. All rights reserved.

  14. Unconstrained monitoring of long-term heart and breath rates during sleep

    International Nuclear Information System (INIS)

    Chen, Wenxi; Zhu, Xin; Wei, Daming; Nemoto, Tetsu; Sugitani, Kayo; Kitamura, Kei-ichiro

    2008-01-01

    An unconstrained method for the long-term monitoring of heart and breath rates during sleep is proposed. The system includes a sensor unit and a web-based network module. The sensor unit is set beneath a pillow to pick up the pressure variations from the head induced by inhalation/exhalation movements and heart pulsation during sleep. The measured pressure signal was digitized and transferred to a remote database server via the network module. A wavelet-based algorithm was employed to detect the heart and breath rates, as well as body movement, during sleep. The overall system was utilized for a total six-month trial operation delivered to a female subject. The profiles of the heart and breath rates on a beat-by-beat and daily basis were obtained. Movements during sleep were also estimated. The results show that the daily average percentage of undetectable periods (UPs) during 881.6 sleep hours over a 180 day period was 17.2%. A total of 89.2% of sleep hours had a UP of not more than 25%. The profile of the heart rate revealed a periodic property that corresponded to the female monthly menstrual cycle. Our system shows promise as a long-term unconstrained monitor for heart and breath rates, and for other physiological parameters related to the quality of sleep and the regularity of the menstrual cycle. (note)

  15. Effects of hot-iron branding on heart rate, breathing rate and behaviour of anaesthetised Steller sea lions.

    Science.gov (United States)

    Walker, K A; Mellish, J E; Weary, D M

    2011-10-01

    This study assessed the heart rate, breathing rate and behavioural responses of 12 juvenile Steller sea lions during hot-iron branding under isoflurane anaesthesia. Physiological and behavioural measures were recorded in four periods: baseline (five minutes), sham branding (one minute), branding (approximately 2.7 minutes) and postbranding (five minutes). No difference in heart rate was noted from baseline to sham branding, but heart rate increased from mean (sem) 78.3 (2.4) bpm in the baseline period to 85.6 (2.5) bpm in the branding period. Heart rate remained elevated in the postbranding period, averaging 84.7 (2.5) bpm. Breathing rate averaged 2.5 (1.0) breaths/minute in the baseline and sham branding periods increased to 8.9 (1.0) breaths/minute during branding, but returned to baseline by the postbranding period. Behaviourally, half of the sea lions exhibited trembling and head and shoulder movements during branding.

  16. Reproducibility for Heart Rate Variability Analysis during 6-Min Walk Test in Patients with Heart Failure and Agreement between Devices.

    Science.gov (United States)

    Braga, Lays Magalhães; Prado, Gustavo Faibischew; Umeda, Iracema Ioco Kikuchi; Kawauchi, Tatiana Satie; Taboada, Adriana Marques Fróes; Azevedo, Raymundo Soares; Pereira Filho, Horacio Gomes; Grupi, César José; Souza, Hayala Cristina Cavenague; Moreira, Dalmo Antônio Ribeiro; Nakagawa, Naomi Kondo

    2016-01-01

    Heart rate variability (HRV) analysis is a useful method to assess abnormal functioning in the autonomic nervous system and to predict cardiac events in patients with heart failure (HF). HRV measurements with heart rate monitors have been validated with an electrocardiograph in healthy subjects but not in patients with HF. We explored the reproducibility of HRV in two consecutive six-minute walk tests (6MW), 60-minute apart, using a heart rate monitor (PolarS810i) and a portable electrocardiograph (called Holter) in 50 HF patients (mean age 59 years, NYHA II, left ventricular ejection fraction ~35%). The reproducibility for each device was analysed using a paired t-test or the Wilcoxon signed-rank test. Additionally, we assessed the agreement between the two devices based on the HRV indices at rest, during the 6MW and during recovery using concordance correlation coefficients (CCC), 95% confidence intervals and Bland-Altman plots. The test-retest for the HRV analyses was reproducible using Holter and PolarS810i at rest but not during recovery. In the second 6MW, patients showed significant increases in rMSSD and walking distance. The PolarS810i measurements had remarkably high concordance correlation [0.86rates, a small effect in increasing differences between Holter and Polar in R-R intervals was observed. In conclusion, our study showed good reproducibility of HRV at rest in two consecutive 6MW using Holter and PolarS810i. Additionally, PolarS810i produced good agreements in short-term HRV indices based on Holter simultaneous recordings at rest, during the 6MW and recovery in HF patients.

  17. Influence of different characteristics of sport on heart rate recovery in elite athletes

    Directory of Open Access Journals (Sweden)

    Anđić Radovan

    2016-01-01

    Full Text Available Introduction: One of the benefits of regular physical activity is lower resting heart rate and its faster recovery after maximal exercise test, as a result of a stronger parasympatic (vagal tone. Heart rate recovery is used as reliable parameter for prescription of the training program and also in prognostic purposes as a parameter of risk for developing cardiovascular diseases. Aim: The purpose of this study is to show significant differences in heart rate recovery after maximal exercise test and resting heart rate among different groups of elite athletes. Material and Methods: This study subjected 575 adult (23.1 ± 4.3 years, male athletes divided into four sport groups: skill, power, mixed and endurance. Every subject performed progressive, maximal cardiopulmonary exercise test on a treadmill. Heart rate recovery in first (ΔHRR1 and third (ΔHRR3 minute was calculated as a difference of maximal heart rate and heart rate in the first and the third minute after cessation of exercise, respectively. Results: Compared to skill, power and mixed group (62.9 ± 11.4; 61.5 ± 10.0; 59.9 ± 10.4 min-1 respectively, significantly lower values od resting heart rate are recorded in the endurance group (56.2 ± 10.6 min-1 (p = 0,05. Also, ΔHRR1 was significantly higher in the endurance group (33.5 ±14.3 min-1 compared to skill, power and mixed group (24.3 ± 10.9; 25.5 ± 11.2; 27.8 ± 15.6 min-1 respectively (p = 0,05. Values od ΔHRR3 were significantly higher in power, mixed and endurance groups (74.8 ± 14.3; 79.5 ± 12.7; 79.4 ± 12.6 min-1 respectively compared to skill group (67.3±16.1 min-1 (p = 0,05. Conclusion: Training endurance group of sports has the most contribution to lower resting heart rate and faster recovery of heart rate in the first minute after exercising, due to dominant parasympatic tone.

  18. Low doses of caffeine reduce heart rate during submaximal cycle ergometry

    Directory of Open Access Journals (Sweden)

    Wetter Thomas J

    2007-10-01

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

  19. Chronic intermittent hypoxia-hypercapnia blunts heart rate responses and alters neurotransmission to cardiac vagal neurons.

    Science.gov (United States)

    Dyavanapalli, Jhansi; Jameson, Heather; Dergacheva, Olga; Jain, Vivek; Alhusayyen, Mona; Mendelowitz, David

    2014-07-01

    Patients with obstructive sleep apnoea experience chronic intermittent hypoxia-hypercapnia (CIHH) during sleep that elicit sympathetic overactivity and diminished parasympathetic activity to the heart, leading to hypertension and depressed baroreflex sensitivity. The parasympathetic control of heart rate arises from pre-motor cardiac vagal neurons (CVNs) located in nucleus ambiguus (NA) and dorsal motor nucleus of the vagus (DMNX). The mechanisms underlying diminished vagal control of heart rate were investigated by studying the changes in blood pressure, heart rate, and neurotransmission to CVNs evoked by acute hypoxia-hypercapnia (H-H) and CIHH. In vivo telemetry recordings of blood pressure and heart rate were obtained in adult rats during 4 weeks of CIHH exposure. Retrogradely labelled CVNs were identified in an in vitro brainstem slice preparation obtained from adult rats exposed either to air or CIHH for 4 weeks. Postsynaptic inhibitory or excitatory currents were recorded using whole cell voltage clamp techniques. Rats exposed to CIHH had increases in blood pressure, leading to hypertension, and blunted heart rate responses to acute H-H. CIHH induced an increase in GABAergic and glycinergic neurotransmission to CVNs in NA and DMNX, respectively; and a reduction in glutamatergic neurotransmission to CVNs in both nuclei. CIHH blunted the bradycardia evoked by acute H-H and abolished the acute H-H evoked inhibition of GABAergic transmission while enhancing glycinergic neurotransmission to CVNs in NA. These changes with CIHH inhibit CVNs and vagal outflow to the heart, both in acute and chronic exposures to H-H, resulting in diminished levels of cardioprotective parasympathetic activity to the heart as seen in OSA patients. © 2014 The Authors. The Journal of Physiology © 2014 The Physiological Society.

  20. Combinatorial effect of nicotine and black tea on heart rate variability: Useful or harmful?

    Science.gov (United States)

    Joukar, S; Sheibani, M

    2017-06-01

    The effect of nicotine on heart rate variability (HRV) is controversial. Autonomic nervous system is the main regulator of heart rhythm, and heart rate variability is an appropriate index to assessment of the effects of the autonomic system on heart. In this study, the combination effect of nicotine and black tea consumption on sympatho-vagal balance and heart rate variability was investigated in rats. Male Wistar rats were randomized into four groups as control, tea (2.5 g/100 cc, daily), nicotine (2 mg/kg/d) and tea plus nicotine groups which treated for 28 days, and in the 29th day, their electrocardiograms (lead II) were recorded. The mean of high-frequency power (HF) in tea, nicotine and tea plus nicotine groups was significantly more than control group (P nicotine and tea + nicotine groups was significantly less than control group (P nicotine and tea + nicotine groups in comparison with control group (P nicotine or their combination with dosages used in this study can increase the heart rate variability and improve the sympatho-vagal balance in rat. © 2017 John Wiley & Sons Ltd.

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

    Directory of Open Access Journals (Sweden)

    García-García Ángel

    2012-03-01

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

  2. Heart rate turbulence as a marker of myocardial electrical instability in children with hypertrophic cardiomyopathy

    Directory of Open Access Journals (Sweden)

    V. A. Makarova

    2014-01-01

    Full Text Available Heart rate turbulence is a myocardial electrical instability marker used to stratify the risk of sudden cardiac death. Fifty children aged 7 to 17 years with hypertrophic cardiomyopathy were examined. The survey program included standard electrocardiography, Doppler echocardiography, and 24-hour Holter ECG monitoring. Heart rate turbulence parameters, such as turbulence onset and turbulence slope, were analyzed. According to turbulence onset greater than zero, heart rate turbulence impairment was identified in 5 of the 24 patients included in the survey. The abnormal turbulence slope values of less than 6 msec/RR were found in 3 patients. Both parameters were abnormal in 1 patient. Heart rate turbulence impairment was significantly more common in children with the non-obstructive form of hypertrophic cardiomyopathy than in those with its obstructive form (χ2=3,05; p=0,08. All the children with abnormal heart rhythm turbulence values had one or more major risk factors for sudden cardiac death, which significantly exceeds their rates in the normal heart rate turbulence groups (χ2=7,11; p=0,007. The patients with abnormal turbulence onset values were more often found to have syncope (χ2=3,2; p=0,02. One such patient was recorded to have unstable ventricular tachycardia (χ2=10,56; p=0,001. Our findings suggest that heart rate turbulence is an additional predictor of the unfavorable course of hypertrophic cardiomyopathy in children. 

  3. The Rate of Addiction in Parents of Children with Congenital Heart Disease Compared with Healthy Children

    Directory of Open Access Journals (Sweden)

    Tahereh Boryri

    2017-03-01

    Full Text Available BackgroundCongenital heart diseases (CHD are the most common congenital anomaly in children and also the leading cause of mortality from congenital anomalies. Various factors including smoking, drinking alcohol and addiction play role in development of congenital heart diseases. This study was conducted with the aim of investigation of the prevalence of addiction in parents of children with congenital heart disease compared with healthy children.Materials and MethodsThis was a case-control study conducted on 320 children with congenital heart disease aged 6 months to 16 years and 320 healthy children as control group. Children referring to Ali Asghar hospital or who were hospitalized in Imam Ali Hospital were included in the study and their demographic characteristics and their parents were collected. Data were analyzed using SPSS 20.ResultsAverage age of diseased and healthy children was 4.08 ± 4.11 and 3.59 ± 2.36, respectively. The rate of addiction of father, mother and parents of children with congenital heart disease was higher than those of children in control group. The most common congenital heart disease was ventricular septal defect (VSD.ConclusionIn overall, this study showed addiction rate of parents in children with congenital heart disease was higher.

  4. Patterns of Interspecific Variation in the Heart Rates of Embryonic Reptiles

    Science.gov (United States)

    Du, Wei-Guo; Ye, Hua; Zhao, Bo; Pizzatto, Ligia; Ji, Xiang; Shine, Richard

    2011-01-01

    New non-invasive technologies allow direct measurement of heart rates (and thus, developmental rates) of embryos. We applied these methods to a diverse array of oviparous reptiles (24 species of lizards, 18 snakes, 11 turtles, 1 crocodilian), to identify general influences on cardiac rates during embryogenesis. Heart rates increased with ambient temperature in all lineages, but (at the same temperature) were faster in lizards and turtles than in snakes and crocodilians. We analysed these data within a phylogenetic framework. Embryonic heart rates were faster in species with smaller adult sizes, smaller egg sizes, and shorter incubation periods. Phylogenetic changes in heart rates were negatively correlated with concurrent changes in adult body mass and residual incubation period among the lizards, snakes (especially within pythons) and crocodilians. The total number of embryonic heart beats between oviposition and hatching was lower in squamates than in turtles or the crocodilian. Within squamates, embryonic iguanians and gekkonids required more heartbeats to complete development than did embryos of the other squamate families that we tested. These differences plausibly reflect phylogenetic divergence in the proportion of embryogenesis completed before versus after laying. PMID:22174948

  5. HEART RATE RECOVERY AFTER EXERCISE AND NEURAL REGULATION OF HEART RATE VARIABILITY IN 30-40 YEAR OLD FEMALE MARATHON RUNNERS

    Directory of Open Access Journals (Sweden)

    Toshio Matsuoka

    2005-03-01

    Full Text Available The aim of the present study was to examine the effects of endurance training on heart rate (HR recovery after exercise and cardiac autonomic nervous system (ANS modulation in female marathon runners by comparing with untrained controls. Six female marathon runners (M group aged 32-40 years and eight age-matched untrained females (C group performed a maximum-effort treadmill running exercise. Maximal oxygen uptake (VO2max was measured during the exercise with a gas analyzer connected to subjects through a face mask. Heart rate, blood pressure and blood lactate were measured before and after the exercise. Rating of perceived exertion (RPE to the exercise was obtained immediately after the exercise. Holter ECG was recorded and analyzed with power spectral analysis of heart rate variability (HRV to investigate the cardiac ANS modulation. The M group had significantly higher VO2max, faster HR recovery after exercise, higher Mean RR, SDRR, HF power and lower LF/HF ratio at rest compared with the C group. The M group also presented greater percent decrease of blood pressure after exercise, although their blood pressure after exercise was higher than the C group. It is suggested that endurance training induced significant alterations in cardiac ANS modulation at rest and significant acceleration of HR recovery after exercise in female marathon runners. Faster HR recovery after exercise in the female marathon runners should result from their higher levels of HRV, higher aerobic capacity and exaggerated blood pressure response to exercise compared with untrained controls.

  6. Predictors of abnormal heart rate response to dipyridamole in patients undergoing myocardial perfusion SPECT

    International Nuclear Information System (INIS)

    De Souza Leao Lima, R.; Machado, L.; Azevedo, A.B.; De Lorenzo, A.

    2011-01-01

    The objective of this study was to identify predictors of abnormal HR response to dipyridamole (DIP) in patients undergoing myocardial perfusion SPECT (MPS). Patients with a reduced heart rate (HR) response to DIP have higher cardiac mortality, but the mechanism is unknown. We studied 432 patients who underwent dual-isotope gated MPS. DIP (0.56 mg/kg) was infused over 4 min, and Tc-99m tetrofosmin was injected 3 min after the end of the infusion. MPS was semiquantitatively interpreted. Left ventricular ejection fraction (LVEF) and volumes were automatically calculated. The population was categorized into quartiles according to HR ratio, and characteristics in each quartile were compared. Logistic regression analysis was performed to identify predictors of abnormal HR response, using the lowest quartile as the independent variable. Patients with abnormal HR response were more frequently without chest pain, with a history of chronic renal failure and taking digoxin. Baseline HR was higher and had fewer symptoms during stress. The stress and rest perfusion defects were greater, but reversibility was not; in addition, LVEF was lower. Multivariable logistic regression analysis demonstrated that the independent predictors of abnormal HR response were baseline HR and low LVEF. LV dysfunction is an independent predictor of abnormal HR response to DIP, and the association between low LVEF and low HR ratio may explain the link between abnormal HR ratio and increased mortality. (author)

  7. A Comparative Survey of Methods for Remote Heart Rate Detection From Frontal Face Videos

    Directory of Open Access Journals (Sweden)

    Chen Wang

    2018-05-01

    Full Text Available Remotely measuring physiological activity can provide substantial benefits for both the medical and the affective computing applications. Recent research has proposed different methodologies for the unobtrusive detection of heart rate (HR using human face recordings. These methods are based on subtle color changes or motions of the face due to cardiovascular activities, which are invisible to human eyes but can be captured by digital cameras. Several approaches have been proposed such as signal processing and machine learning. However, these methods are compared with different datasets, and there is consequently no consensus on method performance. In this article, we describe and evaluate several methods defined in literature, from 2008 until present day, for the remote detection of HR using human face recordings. The general HR processing pipeline is divided into three stages: face video processing, face blood volume pulse (BVP signal extraction, and HR computation. Approaches presented in the paper are classified and grouped according to each stage. At each stage, algorithms are analyzed and compared based on their performance using the public database MAHNOB-HCI. Results found in this article are limited on MAHNOB-HCI dataset. Results show that extracted face skin area contains more BVP information. Blind source separation and peak detection methods are more robust with head motions for estimating HR.

  8. Changes of heart rate variability and prefrontal oxygenation during Tai Chi practice versus arm ergometer cycling

    OpenAIRE

    Lu, Xi; Hui-Chan, Christina Wan-Ying; Tsang, William Wai-Nam

    2016-01-01

    [Purpose] Exercise has been shown to improve cardiovascular fitness and cognitive function. Whether the inclusion of mind over exercise would increase parasympathetic control of the heart and brain activities more than general exercise at a similar intensity is not known. The aim of this study was to compare the effects of Tai Chi (mind-body exercise) versus arm ergometer cycling (body-focused exercise) on the heart rate variability and prefrontal oxygenation level. [Subjects and Methods] A T...

  9. Atrial fibrillation detection by heart rate variability in Poincare plot.

    Science.gov (United States)

    Park, Jinho; Lee, Sangwook; Jeon, Moongu

    2009-12-11

    Atrial fibrillation (AFib) is one of the prominent causes of stroke, and its risk increases with age. We need to detect AFib correctly as early as possible to avoid medical disaster because it is likely to proceed into a more serious form in short time. If we can make a portable AFib monitoring system, it will be helpful to many old people because we cannot predict when a patient will have a spasm of AFib. We analyzed heart beat variability from inter-beat intervals obtained by a wavelet-based detector. We made a Poincare plot using the inter-beat intervals. By analyzing the plot, we extracted three feature measures characterizing AFib and non-AFib: the number of clusters, mean stepping increment of inter-beat intervals, and dispersion of the points around a diagonal line in the plot. We divided distribution of the number of clusters into two and calculated mean value of the lower part by k-means clustering method. We classified data whose number of clusters is more than one and less than this mean value as non-AFib data. In the other case, we tried to discriminate AFib from non-AFib using support vector machine with the other feature measures: the mean stepping increment and dispersion of the points in the Poincare plot. We found that Poincare plot from non-AFib data showed some pattern, while the plot from AFib data showed irregularly irregular shape. In case of non-AFib data, the definite pattern in the plot manifested itself with some limited number of clusters or closely packed one cluster. In case of AFib data, the number of clusters in the plot was one or too many. We evaluated the accuracy using leave-one-out cross-validation. Mean sensitivity and mean specificity were 91.4% and 92.9% respectively. Because pulse beats of ventricles are less likely to be influenced by baseline wandering and noise, we used the inter-beat intervals to diagnose AFib. We visually displayed regularity of the inter-beat intervals by way of Poincare plot. We tried to design an

  10. Heart rate variability and baroreflex sensitivity in bilateral lung transplant recipients.

    Science.gov (United States)

    Fontolliet, Timothée; Gianella, Pietro; Pichot, Vincent; Barthélémy, Jean-Claude; Gasche-Soccal, Paola; Ferretti, Guido; Lador, Frédéric

    2018-01-09

    The effects of lung afferents denervation on cardiovascular regulation can be assessed on bilateral lung transplantation patients. The high-frequency component of heart rate variability is known to be synchronous with breathing frequency. Then, if heart beat is neurally modulated by breathing frequency, we may expect disappearance of high frequency of heart rate variability in bilateral lung transplantation patients. On 11 patients and 11 matching healthy controls, we measured R-R interval (electrocardiography), blood pressure (Portapres ® ) and breathing frequency (ultrasonic device) in supine rest, during 10-min free breathing, 10-min cadenced breathing (0·25 Hz) and 5-min handgrip. We analysed heart rate variability and spontaneous variability of arterial blood pressure, by power spectral analysis, and baroreflex sensitivity, by the sequence method. Concerning heart rate variability, with respect to controls, transplant recipients had lower total power and lower low- and high-frequency power. The low-frequency/high-frequency ratio was higher. Concerning systolic, diastolic and mean arterial pressure variability, transplant recipients had lower total power (only for cadenced breathing), low frequency and low-frequency/high-frequency ratio during free and cadenced breathing. Baroreflex sensitivity was decreased. Denervated lungs induced strong heart rate variability reduction. The higher low-frequency/high-frequency ratio suggested that the total power drop was mostly due to high frequency. These results support the hypothesis that neural modulation from lung afferents contributes to the high frequency of heart rate variability. © 2018 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

  11. Effects and after-effects of chewing gum on vigilance, heart rate, EEG and mood.

    Science.gov (United States)

    Allen, Andrew P; Jacob, Tim J C; Smith, Andrew P

    2014-06-22

    Research has shown that chewing gum improves attention, although the mechanism for this effect remains unclear. This study investigated the effects and after-effects of chewing gum on vigilance, mood, heart rate and EEG. Participants completed a vigilance task four times; at baseline, with or without chewing gum, and twice post-chewing. EEG alpha and beta power at left frontal and temporal lobes, subjective mood and heart rate were assessed. Chewing gum shortened reaction time and increased the rate of hits, although hits fell during the second post-chewing task. Chewing gum heightened heart rate, but only during chewing. Gum also increased beta power at F7 and T3 immediately post-chewing, but not following the post-chewing tasks. The findings show that chewing gum affects several different indicators of alertness. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Lack of evidence for low-dimensional chaos in heart rate variability

    DEFF Research Database (Denmark)

    Kanters, J K; Holstein-Rathlou, N H; Agner, E

    1994-01-01

    INTRODUCTION: The term chaos is used to describe erratic or apparently random time-dependent behavior in deterministic systems. It has been suggested that the variability observed in the normal heart rate may be due to chaos, but this question has not been settled. METHODS AND RESULTS: Heart rate...... in the experimental data, but the prediction error as a function of the prediction length increased at a slower rate than characteristic of a low-dimensional chaotic system. CONCLUSION: There is no evidence for low-dimensional chaos in the time series of RR intervals from healthy human subjects. However, nonlinear...

  13. Changes of heart rate variability and prefrontal oxygenation during Tai Chi practice versus arm ergometer cycling.

    Science.gov (United States)

    Lu, Xi; Hui-Chan, Christina Wan-Ying; Tsang, William Wai-Nam

    2016-11-01

    [Purpose] Exercise has been shown to improve cardiovascular fitness and cognitive function. Whether the inclusion of mind over exercise would increase parasympathetic control of the heart and brain activities more than general exercise at a similar intensity is not known. The aim of this study was to compare the effects of Tai Chi (mind-body exercise) versus arm ergometer cycling (body-focused exercise) on the heart rate variability and prefrontal oxygenation level. [Subjects and Methods] A Tai Chi master was invited to perform Tai Chi and arm ergometer cycling with similar exercise intensity on two separate days. Heart rate variability and prefrontal oxyhemoglobin levels were measured continuously by a RR recorder and near-infrared spectroscopy, respectively. [Results] During Tai Chi exercise, spectral analysis of heart rate variability demonstrated a higher high-frequency power as well as a lower low-frequency/high-frequency ratio than during ergometer cycling, suggesting increased parasympathetic and decreased sympathetic control of the heart. Also, prefrontal oxyhemoglobin and total hemoglobin levels were higher than those during arm ergometer exercise. [Conclusion] These findings suggest that increased parasympathetic control of the heart and prefrontal activities may be associated with Tai Chi practice. Having a "mind" component in Tai Chi could be more beneficial for older adults' cardiac health and cognitive function than body-focused ergometer cycling.

  14. Novel Fingertip Image-Based Heart Rate Detection Methods for a Smartphone

    Directory of Open Access Journals (Sweden)

    Rifat Zaman

    2017-02-01

    Full Text Available We hypothesize that our fingertip image-based heart rate detection methods using smartphone reliably detect the heart rhythm and rate of subjects. We propose fingertip curve line movement-based and fingertip image intensity-based detection methods, which both use the movement of successive fingertip images obtained from smartphone cameras. To investigate the performance of the proposed methods, heart rhythm and rate of the proposed methods are compared to those of the conventional method, which is based on average image pixel intensity. Using a smartphone, we collected 120 s pulsatile time series data from each recruited subject. The results show that the proposed fingertip curve line movement-based method detects heart rate with a maximum deviation of 0.0832 Hz and 0.124 Hz using time- and frequency-domain based estimation, respectively, compared to the conventional method. Moreover, another proposed fingertip image intensity-based method detects heart rate with a maximum deviation of 0.125 Hz and 0.03 Hz using time- and frequency-based estimation, respectively.

  15. Features of Heart Rate Variability Capture Regulatory Changes During Kangaroo Care in Preterm Infants.

    Science.gov (United States)

    Kommers, Deedee R; Joshi, Rohan; van Pul, Carola; Atallah, Louis; Feijs, Loe; Oei, Guid; Bambang Oetomo, Sidarto; Andriessen, Peter

    2017-03-01

    To determine whether heart rate variability (HRV) can serve as a surrogate measure to track regulatory changes during kangaroo care, a period of parental coregulation distinct from regulation within the incubator. Nurses annotated the starting and ending times of kangaroo care for 3 months. The pre-kangaroo care, during-kangaroo care, and post-kangaroo care data were retrieved in infants with at least 10 accurately annotated kangaroo care sessions. Eight HRV features (5 in the time domain and 3 in the frequency domain) were used to visually and statistically compare the pre-kangaroo care and during-kangaroo care periods. Two of these features, capturing the percentage of heart rate decelerations and the extent of heart rate decelerations, were newly developed for preterm infants. A total of 191 kangaroo care sessions were investigated in 11 preterm infants. Despite clinically irrelevant changes in vital signs, 6 of the 8 HRV features (SD of normal-to-normal intervals, root mean square of the SD, percentage of consecutive normal-to-normal intervals that differ by >50 ms, SD of heart rate decelerations, high-frequency power, and low-frequency/high-frequency ratio) showed a visible and statistically significant difference (P heart rate decelerations. HRV-based features may be clinically useful for capturing the dynamic changes in autonomic regulation in response to kangaroo care and other changes in environment and state. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Randomized controlled trial of relaxation music to reduce heart rate in patients undergoing cardiac CT

    Energy Technology Data Exchange (ETDEWEB)

    Ng, Ming Yen [University of Toronto, Department of Medical Imaging, Toronto General Hospital, Toronto, ON (Canada); The University of Hong Kong, Queen Mary Hospital, Department of Diagnostic Radiology, Hong Kong (China); Karimzad, Yasser; Menezes, Ravi J.; Wintersperger, Bernd J.; Li, Qin; Forero, Julian; Paul, Narinder S.; Nguyen, Elsie T. [University of Toronto, Department of Medical Imaging, Toronto General Hospital, Toronto, ON (Canada)

    2016-10-15

    To evaluate the heart rate lowering effect of relaxation music in patients undergoing coronary CT angiography (CCTA), pulmonary vein CT (PVCT) and coronary calcium score CT (CCS). Patients were randomised to a control group (i.e. standard of care protocol) or to a relaxation music group (ie. standard of care protocol with music). The groups were compared for heart rate, radiation dose, image quality and dose of IV metoprolol. Both groups completed State-Trait Anxiety Inventory anxiety questionnaires to assess patient experience. One hundred and ninety-seven patients were recruited (61.9 % males); mean age 56y (19-86 y); 127 CCTA, 17 PVCT, 53 CCS. No significant difference in heart rate, radiation dose, image quality, metoprolol dose and anxiety scores. 86 % of patients enjoyed the music. 90 % of patients in the music group expressed a strong preference to have music for future examinations. The patient cohort demonstrated low anxiety levels prior to CT. Relaxation music in CCTA, PVCT and CCS does not reduce heart rate or IV metoprolol use. Patients showed low levels of anxiety indicating that anxiolytics may not have a significant role in lowering heart rate. Music can be used in cardiac CT to improve patient experience. (orig.)

  17. Changes in heart rate associated with contest outcome in agonistic encounters in lobsters.

    Science.gov (United States)

    Hernáindez-Falcón, Jesús; Basu, Alo C; Govindasamy, Siddhartan; Kravitz, Edward A

    2005-03-01

    Agonistic contests between lobsters housed together in a confined space progress through encounters of increasing intensity until a dominance relationship is established. Once this relationship is established, losing animals continually retreat from the advances of winners. These encounters are likely to consume much energy in both winning and losing animals. Therefore, one might expect involvement of many physiological systems before, during and after fights. Here, we report effects of agonistic encounters on cardiac frequency in winning and losing adult lobsters involved in dyadic interactions. The results show that: (i) small but significant increases in heart rate are observed upon chemical detection of a conspecific; (ii) during agonistic interactions, further increases in heart rate are seen; and (iii) ultimate winners exhibit greater increases in heart rate lasting longer periods of time compared to ultimate losers. Heart rate in winners remains elevated for at least 15 min after the contests have ended and animals have been returned to their home tanks. Reduced effects are seen in second and third pairings between familiar opponents. The sustained changes in heart rate that we observe in winning lobsters may result from hormonal modulation of cardiac function related to the change in social status brought about by contest outcome.

  18. SVM-Based Spectral Analysis for Heart Rate from Multi-Channel WPPG Sensor Signals.

    Science.gov (United States)

    Xiong, Jiping; Cai, Lisang; Wang, Fei; He, Xiaowei

    2017-03-03

    Although wrist-type photoplethysmographic (hereafter referred to as WPPG) sensor signals can measure heart rate quite conveniently, the subjects' hand movements can cause strong motion artifacts, and then the motion artifacts will heavily contaminate WPPG signals. Hence, it is challenging for us to accurately estimate heart rate from WPPG signals during intense physical activities. The WWPG method has attracted more attention thanks to the popularity of wrist-worn wearable devices. In this paper, a mixed approach called Mix-SVM is proposed, it can use multi-channel WPPG sensor signals and simultaneous acceleration signals to measurement heart rate. Firstly, we combine the principle component analysis and adaptive filter to remove a part of the motion artifacts. Due to the strong relativity between motion artifacts and acceleration signals, the further denoising problem is regarded as a sparse signals reconstruction problem. Then, we use a spectrum subtraction method to eliminate motion artifacts effectively. Finally, the spectral peak corresponding to heart rate is sought by an SVM-based spectral analysis method. Through the public PPG database in the 2015 IEEE Signal Processing Cup, we acquire the experimental results, i.e., the average absolute error was 1.01 beat per minute, and the Pearson correlation was 0.9972. These results also confirm that the proposed Mix-SVM approach has potential for multi-channel WPPG-based heart rate estimation in the presence of intense physical exercise.

  19. Comparative evaluation of heart rate-based monitors: Apple Watch vs Fitbit Charge HR.

    Science.gov (United States)

    Bai, Yang; Hibbing, Paul; Mantis, Constantine; Welk, Gregory J

    2018-08-01

    The purpose of this investigation was to examine the validity of energy expenditure (EE), steps, and heart rate measured with the Apple Watch 1 and Fitbit Charge HR. Thirty-nine healthy adults wore the two monitors while completing a semi-structured activity protocol consisting of 20 minutes of sedentary activity, 25 minutes of aerobic exercise, and 25 minutes of light intensity physical activity. Criterion measures were obtained from an Oxycon Mobile for EE, a pedometer for steps, and a Polar heart rate strap worn on the chest for heart rate. For estimating whole-trial EE, the mean absolute percent error (MAPE) from Fitbit Charge HR (32.9%) was more than twice that of Apple Watch 1 (15.2%). This trend was consistent for the individual conditions. Both monitors accurately assessed steps during aerobic activity (MAPE Apple : 6.2%; MAPE Fitbit : 9.4%) but overestimated steps in light physical activity. For heart rate, Fitbit Charge HR produced its smallest MAPE in sedentary behaviors (7.2%), followed by aerobic exercise (8.4%), and light activity (10.1%). The Apple Watch 1 had stronger validity than the Fitbit Charge HR for assessing overall EE and steps during aerobic exercise. The Fitbit Charge HR provided heart rate estimates that were statistically equivalent to Polar monitor.

  20. Heart rate variability in normal-weight patients with polycystic ovary syndrome.

    Science.gov (United States)

    Kilit, Celal; Paşalı Kilit, Türkan

    2017-05-01

    Polycystic ovary syndrome (PCOS) is an endocrine disease closely related to several risk factors of cardiovascular disease. Obese women with PCOS show altered autonomic modulation. The results of studies investigating cardiac autonomic functions of normal-weight women with PCOS are conflicting. The aim of the study was to assess the reactivity of cardiac sympathovagal balance in normal-weight women with PCOS by heart rate variability analysis. We examined the heart rate variability in 60 normal-weight women with PCOS and compared them with that in 60 age-matched healthy women having a similar metabolic profile. Time and frequency domain parameters of heart rate variability were analyzed based on 5-min-long continuous electrocardiography recordings for the following 3 periods: (1) during rest in supine position, (2) during controlled breathing, and (3) during isometric handgrip exercise. Time and frequency domain parameters of heart rate variability for the 3 periods assessed were similar in the two groups. Although modified Ferriman-Gallwey score and serum testosterone and luteinizing hormone levels were significantly higher in women with PCOS, homeostatic model assessment-insulin resistance (HOMA-IR) was not different the between the PCOS and control groups. There were no significant correlations between serum testosterone levels and heart rate variability parameters among the study population. The findings of this study suggest that the reactivity of cardiac sympathovagal balance is not altered in normal-weight women with PCOS having a normal HOMA-IR.

  1. Effects of two newly synthesized analogues of lidocaine on rat arterial blood pressure and heart rate.

    Science.gov (United States)

    Al Rasheed, N M; Al Sayed, M I; Al Zuhair, H H; Al Obaid, A R; Fatani, A J

    2001-04-01

    Two new analogues of lidocaine were synthesized at the College of Pharmacy, King Saud University: compound I (Methyl-2-[2-(N,N-diethylamino) acetamido]-3-cyano-4,5-dimethylbenzoate) and compound II (Methyl-2-[2-(piperidino) acetamido]-3-cyano-4,5-dimethylbenzoate). Their influence on the arterial blood pressure and the heart rate of urethane-anaesthetized rats was studied and compared with the actions of lidocaine. Compounds I, II and lidocaine induced significant dose-dependent decreases in the arterial blood pressure and heart rate, which usually returned to basal values within 3-5 min. There were significant differences in the potency of the three compounds in producing their effects on blood pressure and heart rate (Plidocaine and compound I, respectively. The results of this study also indicated the ineffectiveness of antagonists of autonomic, histaminergic and 5-HT receptor, and various vasodilators in blocking the actions of the three compounds on blood pressure and heart rate. Pretreatment with CaCl(2)significantly reduced the hypotension and bradycardia induced by the three compounds, suggesting the involvement of calcium channels, probably of the L type. Several possible mechanisms are postulated. In conclusion, the results direct attention to the capability of the two new compounds to decrease blood pressure and heart rate; affects that may have clinical potential. Copyright 2001 Academic Press.

  2. Dynamic neural networking as a basis for plasticity in the control of heart rate.

    Science.gov (United States)

    Kember, G; Armour, J A; Zamir, M

    2013-01-21

    A model is proposed in which the relationship between individual neurons within a neural network is dynamically changing to the effect of providing a measure of "plasticity" in the control of heart rate. The neural network on which the model is based consists of three populations of neurons residing in the central nervous system, the intrathoracic extracardiac nervous system, and the intrinsic cardiac nervous system. This hierarchy of neural centers is used to challenge the classical view that the control of heart rate, a key clinical index, resides entirely in central neuronal command (spinal cord, medulla oblongata, and higher centers). Our results indicate that dynamic networking allows for the possibility of an interplay among the three populations of neurons to the effect of altering the order of control of heart rate among them. This interplay among the three levels of control allows for different neural pathways for the control of heart rate to emerge under different blood flow demands or disease conditions and, as such, it has significant clinical implications because current understanding and treatment of heart rate anomalies are based largely on a single level of control and on neurons acting in unison as a single entity rather than individually within a (plastically) interconnected network. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. Universal design of a microcontroller and IoT system to detect the heart rate

    Science.gov (United States)

    Uwamahoro, Raphael; Mushikiwabeza, Alexie; Minani, Gerard; Mohan Murari, Bhaskar

    2017-11-01

    Heart rate analysis provides vital information of the present condition of the human body. It helps medical professionals in diagnosis of various malfunctions of the body. The limitation of vision impaired and blind people to access medical devices cause a considerable loss of life. In this paper, we intended to develop a heart rate detection system that is usable for people with normal and abnormal vision. The system is based on a non-invasive method of measuring the variation of the tissue blood flow rate by means of a photo transmitter and detector through fingertip known as photoplethysmography (PPG). The signal detected is firstly passed through active low pass filter and then amplified by a two stages high gain amplifier. The amplified signal is feed into the microcontroller to calculate the heart rate and displays the heart beat via sound systems and Liquid Crystal Display (LCD). To distinguish arrhythmia, normal heart rate and abnormal working conditions of the system, recognition is provided in different sounds, LCD readings and Light Emitting Diodes (LED).

  4. A single dose of dark chocolate increases parasympathetic modulation and heart rate variability in healthy subjects

    Directory of Open Access Journals (Sweden)

    Ana Amélia Machado DUARTE

    Full Text Available ABSTRACT Objective: The aim of this study was to investigate the acute effect of a single dose of dark chocolate (70% cocoa on blood pressure and heart rate variability. Methods: Thirty-one healthy subjects (aged 18-25 years; both sexes were divided into two groups: 10 subjects in the white chocolate (7.4 g group and 21 in the dark chocolate (10 g group; measurements were performed at the university's physiology lab. An electrocardiogram measured the sympathovagal balance by spectral and symbolic analysis. Results: A single dose of dark chocolate significantly reduced systolic blood pressure and heart rate. After consuming 10 g of dark chocolate, significant increases were observed for heart rate variability, standard deviation of RR intervals standard deviation of all NN intervals, square root of the mean squared differences between adjacent normal RR intervals root mean square of successive differences, and an increase in the high frequency component in absolute values, representing the parasympathetic modulation. Conclusion: In conclusion the importance of our results lies in the magnitude of the response provoked by a single dose of cocoa. Just 10 g of cocoa triggered a significant increase in parasympathetic modulation and heart rate variability. These combined effects can potentially increase life expectancy because a reduction in heart rate variability is associated with several cardiovascular diseases and higher mortality.

  5. SVM-Based Spectral Analysis for Heart Rate from Multi-Channel WPPG Sensor Signals

    Directory of Open Access Journals (Sweden)

    Jiping Xiong

    2017-03-01

    Full Text Available Although wrist-type photoplethysmographic (hereafter referred to as WPPG sensor signals can measure heart rate quite conveniently, the subjects’ hand movements can cause strong motion artifacts, and then the motion artifacts will heavily contaminate WPPG signals. Hence, it is challenging for us to accurately estimate heart rate from WPPG signals during intense physical activities. The WWPG method has attracted more attention thanks to the popularity of wrist-worn wearable devices. In this paper, a mixed approach called Mix-SVM is proposed, it can use multi-channel WPPG sensor signals and simultaneous acceleration signals to measurement heart rate. Firstly, we combine the principle component analysis and adaptive filter to remove a part of the motion artifacts. Due to the strong relativity between motion artifacts and acceleration signals, the further denoising problem is regarded as a sparse signals reconstruction problem. Then, we use a spectrum subtraction method to eliminate motion artifacts effectively. Finally, the spectral peak corresponding to heart rate is sought by an SVM-based spectral analysis method. Through the public PPG database in the 2015 IEEE Signal Processing Cup, we acquire the experimental results, i.e., the average absolute error was 1.01 beat per minute, and the Pearson correlation was 0.9972. These results also confirm that the proposed Mix-SVM approach has potential for multi-channel WPPG-based heart rate estimation in the presence of intense physical exercise.

  6. Thermal effect on heart rate and hemodynamics in vitelline arteries of stage 18 chicken embryos.

    Science.gov (United States)

    Lee, Jung Yeop; Lee, Sang Joon

    2010-12-01

    We investigated the thermal effects on heart rate, hemodynamics, and response of vitelline arteries of stage-18 chicken embryos. Heart rate was monitored by a high-speed imaging method, while hemodynamic quantities were evaluated using a particle image velocimetry (PIV) technique. Experiments were carried out at seven different temperatures (36-42 °C with 1 °C interval) after 1h of incubation to stabilize the heart rate. The heart rate increased in a linear manner (r = 0.992). Due to the increased cardiac output (or heart rate), the hemodynamic quantities such as mean velocity (U(mean)), velocity fluctuation (U(fluc)), and peak velocity (U(peak)) also increased with respect to the Womersley number (Ω) in the manner r = 0.599, 0.693, and 0.725, respectively. This indicates that the mechanical force exerting on the vessel walls increases. However, the active response (or regulation) of the vitelline arteries was not observed in this study. Copyright © 2010 Elsevier Ltd. All rights reserved.

  7. Randomized controlled trial of relaxation music to reduce heart rate in patients undergoing cardiac CT

    International Nuclear Information System (INIS)

    Ng, Ming Yen; Karimzad, Yasser; Menezes, Ravi J.; Wintersperger, Bernd J.; Li, Qin; Forero, Julian; Paul, Narinder S.; Nguyen, Elsie T.

    2016-01-01

    To evaluate the heart rate lowering effect of relaxation music in patients undergoing coronary CT angiography (CCTA), pulmonary vein CT (PVCT) and coronary calcium score CT (CCS). Patients were randomised to a control group (i.e. standard of care protocol) or to a relaxation music group (ie. standard of care protocol with music). The groups were compared for heart rate, radiation dose, image quality and dose of IV metoprolol. Both groups completed State-Trait Anxiety Inventory anxiety questionnaires to assess patient experience. One hundred and ninety-seven patients were recruited (61.9 % males); mean age 56y (19-86 y); 127 CCTA, 17 PVCT, 53 CCS. No significant difference in heart rate, radiation dose, image quality, metoprolol dose and anxiety scores. 86 % of patients enjoyed the music. 90 % of patients in the music group expressed a strong preference to have music for future examinations. The patient cohort demonstrated low anxiety levels prior to CT. Relaxation music in CCTA, PVCT and CCS does not reduce heart rate or IV metoprolol use. Patients showed low levels of anxiety indicating that anxiolytics may not have a significant role in lowering heart rate. Music can be used in cardiac CT to improve patient experience. (orig.)

  8. The magnitude and course of exercise-induced stroke volume changes determine the exercise tolerance in heart transplant recipients with heart failure and normal ejection fraction

    Czech Academy of Sciences Publication Activity Database

    Meluzín, J.; Hude, P.; Leinveber, P.; Jurák, Pavel; Soukup, L.; Viščor, Ivo; Špinarová, L.; Štěpánová, R.; Podroužková, H.; Vondra, Vlastimil; Langer, P.; Němec, P.

    2014-01-01

    Roč. 20, č. 1 (2014), s. 674-687 ISSN 1205-6626 R&D Projects: GA MŠk(CZ) LO1212 Keywords : heart failure * stroke volume index * exercise tolerance * bioimpedance Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery Impact factor: 0.758, year: 2013

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

    Science.gov (United States)

    DeWeese, Jo

    2009-01-01

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

  10. HEART RATE VARIABILITY CLASSIFICATION USING SADE-ELM CLASSIFIER WITH BAT FEATURE SELECTION

    Directory of Open Access Journals (Sweden)

    R Kavitha

    2017-07-01

    Full Text Available The electrical activity of the human heart is measured by the vital bio medical signal called ECG. This electrocardiogram is employed as a crucial source to gather the diagnostic information of a patient’s cardiopathy. The monitoring function of cardiac disease is diagnosed by documenting and handling the electrocardiogram (ECG impulses. In the recent years many research has been done and developing an enhanced method to identify the risk in the patient’s body condition by processing and analysing the ECG signal. This analysis of the signal helps to find the cardiac abnormalities, arrhythmias, and many other heart problems. ECG signal is processed to detect the variability in heart rhythm; heart rate variability is calculated based on the time interval between heart beats. Heart Rate Variability HRV is measured by the variation in the beat to beat interval. The Heart rate Variability (HRV is an essential aspect to diagnose the properties of the heart. Recent development enhances the potential with the aid of non-linear metrics in reference point with feature selection. In this paper, the fundamental elements are taken from the ECG signal for feature selection process where Bat algorithm is employed for feature selection to predict the best feature and presented to the classifier for accurate classification. The popular machine learning algorithm ELM is taken for classification, integrated with evolutionary algorithm named Self- Adaptive Differential Evolution Extreme Learning Machine SADEELM to improve the reliability of classification. It combines Effective Fuzzy Kohonen clustering network (EFKCN to be able to increase the accuracy of the effect for HRV transmission classification. Hence, it is observed that the experiment carried out unveils that the precision is improved by the SADE-ELM method and concurrently optimizes the computation time.

  11. Influence of heart failure on resting lung volumes in patients with COPD

    Science.gov (United States)

    de Souza, Aline Soares; Sperandio, Priscila Abreu; Mazzuco, Adriana; Alencar, Maria Clara; Arbex, Flávio Ferlin; de Oliveira, Mayron Faria; O'Donnell, Denis Eunan; Neder, José Alberto

    2016-01-01

    ABSTRACT Objective: To evaluate the influence of chronic heart failure (CHF) on resting lung volumes in patients with COPD, i.e., inspiratory fraction-inspiratory capacity (IC)/TLC-and relative inspiratory reserve-[1 − (end-inspiratory lung volume/TLC)]. Methods: This was a prospective study involving 56 patients with COPD-24 (23 males/1 female) with COPD+CHF and 32 (28 males/4 females) with COPD only-who, after careful clinical stabilization, underwent spirometry (with forced and slow maneuvers) and whole-body plethysmography. Results: Although FEV1, as well as the FEV1/FVC and FEV1/slow vital capacity ratios, were higher in the COPD+CHF group than in the COPD group, all major "static" volumes-RV, functional residual capacity (FRC), and TLC-were lower in the former group (p < 0.05). There was a greater reduction in FRC than in RV, resulting in the expiratory reserve volume being lower in the COPD+CHF group than in the COPD group. There were relatively proportional reductions in FRC and TLC in the two groups; therefore, IC was also comparable. Consequently, the inspiratory fraction was higher in the COPD+CHF group than in the COPD group (0.42 ± 0.10 vs. 0.36 ± 0.10; p < 0.05). Although the tidal volume/IC ratio was higher in the COPD+CHF group, the relative inspiratory reserve was remarkably similar between the two groups (0.35 ± 0.09 vs. 0.44 ± 0.14; p < 0.05). Conclusions: Despite the restrictive effects of CHF, patients with COPD+CHF have relatively higher inspiratory limits (a greater inspiratory fraction). However, those patients use only a part of those limits, probably in order to avoid critical reductions in inspiratory reserve and increases in elastic recoil. PMID:27832235

  12. Heart Rate Variability Is Associated with Exercise Capacity in Patients with Cardiac Syndrome X.

    Directory of Open Access Journals (Sweden)

    Dai-Yin Lu

    Full Text Available Heart rate variability (HRV reflects the healthiness of autonomic nervous system, which is associated with exercise capacity. We therefore investigated whether HRV could predict the exercise capacity in the adults with cardiac syndrome X (CSX. A total of 238 subjects (57±12 years, 67.8% men, who were diagnosed as CSX by the positive exercise stress test and nearly normal coronary angiogram were enrolled. Power spectrum from the 24-hour recording of heart rate was analyzed in frequency domain using total power (TP and spectral components of the very low frequency (VLF, low frequency (LF and high frequency (HF ranges. Among the study population, 129 subjects with impaired exercise capacity during the treadmill test had significantly lower HRV indices than those with preserved exercise capacity (≥90% of the age predicted maximal heart rate. After accounting for age, sex, and baseline SBP and heart rate, VLF (odds ratio per 1SD and 95% CI: 2.02, 1.19-3.42, LF (1.67, 1.10-2.55, and TP (1.82, 1.17-2.83 remained significantly associated with preserved exercise capacity. In addition, increased HRV indices were also associated with increased exercise duration, rate-pressure product, and heart rate recovery, independent of age, body mass index, and baseline SBP and heart rate. In subgroup analysis, HRV indices demonstrated similar predictive values related to exercise capacity across various subpopulations, especially in the young. In patients with CSX, HRV was independently associated with exercise capacity, especially in young subjects. The healthiness of autonomic nervous system may have a role in modulating the exercise capacity in patients with CSX.

  13. Proton upset rate prediction: a new sensitive volume concept definition

    International Nuclear Information System (INIS)

    Inguimbert, Christophe

    1999-01-01

    We present a model for predicting proton induced single event upset rate. The approach uses heavy ion cross section experimental data combined with nuclear reaction calculations in order to determine the proton upset cross section. The p+Si nuclear reaction as well as the Si(p, p)Si Coulombic scattering are described. The upset rate calculation depends on the energy deposited available in the charge collection region (sensitive region). This region is treated as a rectangular parallelepiped of thickness d at depth h. The sensitive thickness d is used as an input parameter in our model we have developed an original method to probe the sensitive region to evaluate d with reasonable accuracy d. We use short range ions and we propose a new mathematical analysis of these experimental data to determine h and d. This method consists in de-convoluting the heavy ion upset cross section σ_S_E_U(r) by the LET function of the incident ion LET(r) (r is the range of the incident ion). Our results are in relatively good agreement with other models. The accuracy of the method allows us to discuss the validity of the sensitive volume concept. Furthermore, we extrapolate an internal gain factor α that permit to take into account the charge collection mechanisms. α and d serve for quick and reasonably accurate prediction of proton induced SEU cross section in microelectronic devices. (author) [fr

  14. The relationship between body temperature, heart rate, breathing rate, and rate of oxygen consumption, in the tegu lizard (Tupinambis merianae) at various levels of activity.

    Science.gov (United States)

    Piercy, Joanna; Rogers, Kip; Reichert, Michelle; Andrade, Denis V; Abe, Augusto S; Tattersall, Glenn J; Milsom, William K

    2015-12-01

    The present study determined whether EEG and/or EMG recordings could be used to reliably define activity states in the Brazilian black and white tegu lizard (Tupinambis merianae) and then examined the interactive effects of temperature and activity states on strategies for matching O2 supply and demand. In a first series of experiments, the rate of oxygen consumption (VO2), breathing frequency (fR), heart rate (fH), and EEG and EMG (neck muscle) activity were measured in different sleep/wake states (sleeping, awake but quiet, alert, or moving). In general, metabolic and cardio-respiratory changes were better indictors of the transition from sleep to wake than were changes in the EEG and EMG. In a second series of experiments, the interactive effects of temperature (17, 27 and 37 °C) and activity states on fR, tidal volume (VT), the fraction of oxygen extracted from the lung per breath (FIO2-FEO2), fH, and the cardiac O2 pulse were quantified to determine the relative roles of each of these variables in accommodating changes in VO2. The increases in oxygen supply to meet temperature- and activity-induced increases in oxygen demand were produced almost exclusively by increases in fH and fR. Regression analysis showed that the effects of temperature and activity state on the relationships between fH, fR and VO2 was to extend a common relationship along a single curve, rather than separate relationships for each metabolic state. For these lizards, the predictive powers of fR and fH were maximized when the effects of changes in temperature, digestive state and activity were pooled. However, the best r(2) values obtained were 0.63 and 0.74 using fR and fH as predictors of metabolic rate, respectively.

  15. Relationship between linear and nonlinear dynamics of heart rate and impairment of lung function in COPD patients

    Directory of Open Access Journals (Sweden)

    Mazzuco A

    2015-08-01

    Full Text Available Adriana Mazzuco,1 Wladimir Musetti Medeiros,2 Milena Pelosi Rizk Sperling,1 Aline Soares de Souza,2 Maria Clara Noman Alencar,2 Flávio Ferlin Arbex,2 José Alberto Neder,2,3 Ross Arena,4 Audrey Borghi-Silva1 1Cardiopulmonary Physiotherapy Laboratory, Federal University of São Carlos, São Carlos, 2Pulmonary Function and Clinical Exercise Physiology Unit, Respiratory Division, Department of Medicine, Federal University of São Paulo, São Paulo, Brazil; 3Laboratory of Clinical Exercise Physiology, Division of Respiratory and Critical Care Medicine, Department of Medicine, Queen’s University, Kingston, ON, Canada; 4Department of Physical Therapy and Integrative Physiology Laboratory, College of Applied Health Sciences, University of Illinois Chicago, Chicago, IL, USA Background: In chronic obstructive pulmonary disease (COPD, functional and structural impairment of lung function can negatively impact heart rate variability (HRV; however, it is unknown if static lung volumes and lung diffusion capacity negatively impacts HRV responses. We investigated whether impairment of static lung volumes and lung diffusion capacity could be related to HRV indices in patients with moderate to severe COPD. Methods: Sixteen sedentary males with COPD were enrolled in this study. Resting blood gases, static lung volumes, and lung diffusion capacity for carbon monoxide (DLCO were measured. The RR interval (RRi was registered in the supine, standing, and seated positions (10 minutes each and during 4 minutes of a respiratory sinus arrhythmia maneuver (M-RSA. Delta changes (Δsupine-standing and Δsupine-M-RSA of the standard deviation of normal RRi, low frequency (LF, normalized units [nu] and high frequency (HF [nu], SD1, SD2, alpha1, alpha2, and approximate entropy (ApEn indices were calculated. Results: HF, LF, SD1, SD2, and alpha1 deltas significantly correlated with forced expiratory volume in 1 second, DLCO, airway resistance, residual volume, inspiratory

  16. Real-life indications to ivabradine treatment for heart rate optimization in patients with chronic systolic heart failure.

    Science.gov (United States)

    Tondi, Lara; Fragasso, Gabriele; Spoladore, Roberto; Pinto, Giuseppe; Gemma, Marco; Slavich, Massimo; Godino, Cosmo; Salerno, Anna; Montanaro, Claudia; Margonato, Alberto

    2018-05-11

    : Ivabradine is a selective and specific inhibitor of If current. With its pure negative chronotropic action, it is recommended by European Society of Cardiology and American College of Cardiology/American Heart Association guidelines in symptomatic heart failure patients (NYHA ≥ 2) with ejection fraction 35% or less, sinus rhythm and heart rate (HR) at least 70 bpm, despite maximally titrated β-blocker therapy. Data supporting this indication mainly derive from the SHIFT study, in which ivabradine reduced the combined endpoint of mortality and hospitalization, despite the fact that only 26% of patients enrolled were on optimal β-blocker doses. The aim of the present analysis is to establish the real-life eligibility for ivabradine in a population of patients with systolic heart failure, regularly attending a single heart failure clinic and treated according to guideline-directed medical therapy (GDMT). The clinical cards of 308 patients with heart failure with reduced ejection fraction (HFrEF) through a 68-month period of observation were retrospectively analyzed. GDMT, including β-blocker up-titration to maximal tolerated dose, was implemented during consecutive visits at variable intervals. Demographic, clinical and echocardiographic data were collected at each visit, together with 12-leads ECG and N-terminal pro-B-type natriuretic peptide levels. Out of 308 analyzed HFrEF patients, 220 (71%) were on effective β-blocker therapy, up-titrated to effective/maximal tolerated dose (55 ± 28% of maximal dose) (HR 67 ± 10 bpm). Among the remaining 88 patients, 10 (3.2%) were on maximally tolerated β blocker and ivabradine; 21 patients (6.8%), despite being on maximal tolerated β-blocker dose, had still HR ≥70 bpm, ejection fraction 35% or less and were symptomatic NYHA ≥2, being therefore eligible for ivabradine treatment. The remaining 57 (18%) patients were not on β blocker due to either intolerance or major contraindications. Among

  17. Evaluation of sympathetic nerve system activity with MIBG. Comparison with heart rate variability

    International Nuclear Information System (INIS)

    Kurata, Chinori; Wakabayashi, Yasushi; Shouda, Sakae; Mikami, Tadashi; Tawarahara, Kei; Sugiyama, Tsuyoshi; Nakano, Tomoyasu; Suzuki, Toshihiko.

    1997-01-01

    Authors attempted to elucidate the relations of plasma concentration of norepinephrine (pNE) and findings of heart rate variability and MIBG myocardial scintigraphy and evaluated cardiac autonomic nervous activity in chronic renal failure. Subjects were 211 patients with various heart diseases (coronary artery lesion, cardiomyopathy, hypertension, diabetes mellitus, renal failure and so on), 60 patients with artificial kidney due to chronic renal failure, 13 of whom were found to have coronary arterial disease by Tl myocardial scintigraphy, and 14 normal volunteers. ECG was recorded with the portable recorder for heart rate variability. Together with collection of blood for pNE measurement, myocardial scintigraphy was done at 15 and 150 min after intravenous administration of 111 MBq of MIBG for acquisition of early and delayed, respectively, images of the frontal breast. Accumulation at and elimination during the time points of MIBG were computed in cps unit. Variability of heart rate was found to have the correlation positive with MIBG delayed accumulation and negative with the elimination, and pNE, negative with heart rate variability and the delayed accumulation and positive with the elimination. Thus cardiac autonomic nervous abnormality was suggested to occur before uremic cardiomyopathy. (K.H.)

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

    DEFF Research Database (Denmark)

    Hansen, Tine Willum; Thijs, Lutgarde; Staessen, Jan A.

    2008-01-01

    The evidence relating mortality and morbidity to heart rate remains inconsistent. We performed 24-hour ambulatory blood pressure monitoring in 6928 subjects (not on beta-blockers; mean age: 56.2 years; 46.5% women) enrolled in prospective population studies in Denmark, Belgium, Japan, Sweden......, Uruguay, and China. We computed standardized hazard ratios for heart rate, while stratifying for cohort, and adjusting for blood pressure and other cardiovascular risk factors. Over 9.6 years (median), 850, 325, and 493 deaths accrued for total, cardiovascular, and noncardiovascular mortality......, respectively. The incidence of fatal combined with nonfatal end points was 805, 363, 439, and 324 for cardiovascular, stroke, cardiac, and coronary events, respectively. Twenty-four-hour heart rate predicted total (hazard ratio: 1.15) and noncardiovascular (hazard ratio: 1.18) mortality but not cardiovascular...

  19. Vigorous physical activity predicts higher heart rate variability among younger adults.

    Science.gov (United States)

    May, Richard; McBerty, Victoria; Zaky, Adam; Gianotti, Melino

    2017-06-14

    Baseline heart rate variability (HRV) is linked to prospective cardiovascular health. We tested intensity and duration of weekly physical activity as predictors of heart rate variability in young adults. Time and frequency domain indices of HRV were calculated based on 5-min resting electrocardiograms collected from 82 undergraduate students. Hours per week of both moderate and vigorous activity were estimated using the International Physical Activity Questionnaire. In regression analyses, hours of vigorous physical activity, but not moderate activity, significantly predicted greater time domain and frequency domain indices of heart rate variability. Adjusted for weekly frequency, greater daily duration of vigorous activity failed to predict HRV indices. Future studies should test direct measurements of vigorous activity patterns as predictors of autonomic function in young adulthood.

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

    DEFF Research Database (Denmark)

    Sorensen, Gertrud Laura; Kempfner, Jacob; Zoetmulder, Marielle

    2012-01-01

    The objective of this study was to determine whether patients with Parkinson's disease with and without rapid‐eye‐movement sleep behavior disorder and patients with idiopathic rapid‐eye‐movement sleep behavior disorder have an attenuated heart rate response to arousals or to leg movements during...... sleep compared with healthy controls. Fourteen and 16 Parkinson's patients with and without rapid‐eye‐movement sleep behavior disorder, respectively, 11 idiopathic rapid‐eye‐movement sleep behavior disorder patients, and 17 control subjects underwent 1 night of polysomnography. The heart rate response...... associated with arousal or leg movement from all sleep stages was analyzed from 10 heartbeats before the onset of the sleep event to 15 heartbeats following onset of the sleep event. The heart rate reponse to arousals was significantly lower in both parkinsonian groups compared with the control group...

  1. Age-related disappearance of Mayer-like heart rate waves

    Science.gov (United States)

    Jarisch, W. R.; Ferguson, J. J.; Shannon, R. P.; Wei, J. Y.; Goldberger, A. L.

    1987-01-01

    The effect of age on the principal spectral components of heart rate obtained immediately after passive upright tilt was investigated in human subjects who underwent a 60-deg tilt over 9 sec. Two groups were examined, the first of which consisting of healthy male subjects aged 22-26 years, while the second was comprised of subjects aged 65-84 years on no medication; radiograms were recorded continuously beginning just prior to tilt until 3 min posttilt. The results of spectral analysis showed that elderly subjects did not exhibit the Mayer-like heart rate waves (the 0.07-0.09 Hz oscillations) that were present in the spectra of young subjects immediately after passive upright tilt. The findings are consistent with the concept of a 'dysautonomia of aging'. It is suggested that postural stress testing with spectral analysis of heart rate fluctuations may provide a useful way of assessing physiologic vs chronologic age.

  2. Effect of partial sports massage on blood pressure and heart rate

    Directory of Open Access Journals (Sweden)

    T.D. Pystupa

    2013-12-01

    Full Text Available With the growing popularity and demand for different types of massages (including sports is a growing need for research on specific forms. There is also a need to study the advantages and effects on various body functions. The objective was to study the effect of partial sports massage on blood pressure and heart rate in both men and women. Material and methods. Research has been extended 80 healthy men and women are physically active (age 20-25 years. Blood pressure and heart rate were made on the left arm automatic digital device (model HEM - 907. The device is intended to measure blood pressure. It is established that it is possible to verify the existing beliefs. This promotes more efficient use of massage therapy. Conclusions . Sports massage has an effect on hemodynamic changes, the increase (decrease in blood pressure acceleration (deceleration of the heart rate. It depends on what part of the body exposed to the massage procedure.

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

    International Nuclear Information System (INIS)

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

    2011-01-01

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

  4. Effect of the Torrance Creative Thinking Test on Heart Rate Signal Features

    Directory of Open Access Journals (Sweden)

    Zakeri S.

    2016-02-01

    Full Text Available Aims: Showing a meta-cognitive aspect, creativity is related to higher mental processes such as thinking, intelligence, imagination, and information process. There are many studies on the physiological bases of creativity. The aim of this study was to investigate the effects of creative thinking on the heart rate signal. Materials & Methods: In this semi-experimental study, 52 medical engineering, electrical, and control students of Sahand University were studied in 2012. The subjects were selected via accessible sampling method. To assess the level of the students’ creative thinking, Torrance Tests of Creative Thinking (B form; figural was used. Before and during creative thinking test, heart signal in the rest position was recorded by 1000Hz sampling frequency. Data was analyzed using Wilcoxon non-parametric test.   Findings: There was an increase in the mean heart power amplitude during creative thinking than the rest position. However, passing time and conducting the last sessions of the creativity test, it showed a reduction. There was an increase in the heart rate in persons with high creativity than those with low creativity. In addition, based on the test scores, there was a higher creativity level in females and three-lingual persons than males and bi-lingual persons, respectively. There was an increase in the heart rate in females than males (p=0.0398. Nevertheless, there was no significant difference between three-lingual and bilingual persons (p>0.05.    Conclusion: Creative thinking results in an increase in the heart rate in persons with high creativity than persons with low creativity. Therefore, the creativity level can be detected via heart signal. 

  5. Correlation of radiation dose and heart rate in dual-source computed tomography coronary angiography

    International Nuclear Information System (INIS)

    Laspas, Fotios; Roussakis, Arkadios; Kritikos, Nikolaos; Efthimiadou, Roxani; Kehagias, Dimitrios; Andreou, John; Tsantioti, Dimitra

    2011-01-01

    Background: Computed tomography coronary angiography (CTCA) has been widely used since the introduction of 64-slice scanners and dual-source CT technology, but the relatively high radiation dose remains a major concern. Purpose: To evaluate the relationship between radiation exposure and heart rate (HR), in dual-source CTCA. Material and Methods: Data from 218 CTCA examinations, performed with a dual-source 64-slices scanner, were statistically evaluated. Effective radiation dose, expressed in mSv, was calculated as the product of the dose-length product (DLP) times a conversion coefficient for the chest (mSv = DLPx0.017). Heart rate range and mean heart rate, expressed in beats per minute (bpm) of each individual during CTCA, were also provided by the system. Statistical analysis of effective dose and heart rate data was performed by using Pearson correlation coefficient and two-sample t-test. Results: Mean HR and effective dose were found to have a borderline positive relationship. Individuals with a mean HR >65 bpm observed to receive a statistically significant higher effective dose as compared to those with a mean HR =65 bpm. Moreover, a strong correlation between effective dose and variability of HR of more than 20 bpm was observed. Conclusion: Dual-source CT scanners are considered to have the capability to provide diagnostic examinations even with high HR and arrhythmias. However, it is desirable to keep the mean heart rate below 65 bpm and heart rate fluctuation less than 20 bpm in order to reduce the radiation exposure

  6. Randomized controlled trial of relaxation music to reduce heart rate in patients undergoing cardiac CT.

    Science.gov (United States)

    Ng, Ming Yen; Karimzad, Yasser; Menezes, Ravi J; Wintersperger, Bernd J; Li, Qin; Forero, Julian; Paul, Narinder S; Nguyen, Elsie T

    2016-10-01

    To evaluate the heart rate lowering effect of relaxation music in patients undergoing coronary CT angiography (CCTA), pulmonary vein CT (PVCT) and coronary calcium score CT (CCS). Patients were randomised to a control group (i.e. standard of care protocol) or to a relaxation music group (ie. standard of care protocol with music). The groups were compared for heart rate, radiation dose, image quality and dose of IV metoprolol. Both groups completed State-Trait Anxiety Inventory anxiety questionnaires to assess patient experience. One hundred and ninety-seven patients were recruited (61.9 % males); mean age 56y (19-86 y); 127 CCTA, 17 PVCT, 53 CCS. No significant difference in heart rate, radiation dose, image quality, metoprolol dose and anxiety scores. 86 % of patients enjoyed the music. 90 % of patients in the music group expressed a strong preference to have music for future examinations. The patient cohort demonstrated low anxiety levels prior to CT. Relaxation music in CCTA, PVCT and CCS does not reduce heart rate or IV metoprolol use. Patients showed low levels of anxiety indicating that anxiolytics may not have a significant role in lowering heart rate. Music can be used in cardiac CT to improve patient experience. • Relaxation music does not reduce heart rate in cardiac CT • Relaxation music does not reduce beta-blocker use in cardiac CT • Relaxation music has no effect on cardiac CT image quality • Low levels of anxiety are present in patients prior to cardiac CT • Patients enjoyed the relaxation music and this results in improved patient experience.

  7. [Correlation between resting heart rate and blood glucose level in elderly patients with coronary heart disease and diabetes mellitus].

    Science.gov (United States)

    Liang, Dong-Liang; Li, Xiao-Ying; Wang, Lin; Xu, Hao; Tuo, Xi-Ping; Jian, Zai-Jin; Wang, Xiao-Na; Yun, Ji-Li; Zhang, Xu; Wang, Si-Yue

    2016-05-01

    To explore the correlation between resting heart rate (RHR) and blood glucose level in elderly patients with coronary heart disease (CHD) complicated by diabetes mellitus. Between April and July, 2011, a total of 1336 outpatients over 60 years of age recruited from 165 hospitals were asked to complete a questionnaire and received blood glucose and RHR examination. According to baseline RHR, the patients were divided into 3 groups with HRH blood glucose control rate. HbA1c levels in the total, male and female patients differed significantly among the 3 groups (F=15.436, 15.436, and 24.270, respectively, PBlood glucose control rate in the total, male and female patients also differed significantly among the 3 groups (χ(2)=13.471, 6.752, and 6.522, respectively, Pblood glucose control failure of 1.99 (95% CI: 1.23-2.37, Pblood glucose level, and an increased RHR is associated with an increased risk of poor blood glucose control. Rigorous RHR control in such high-risk patients may prove beneficial for both blood glucose control and secondary prevention of CHD.

  8. Desmin loss and mitochondrial damage precede left ventricular systolic failure in volume overload heart failure.

    Science.gov (United States)

    Guichard, Jason L; Rogowski, Michael; Agnetti, Giulio; Fu, Lianwu; Powell, Pamela; Wei, Chih-Chang; Collawn, James; Dell'Italia, Louis J

    2017-07-01

    Heart failure due to chronic volume overload (VO) in rats and humans is characterized by disorganization of the cardiomyocyte desmin/mitochondrial network. Here, we tested the hypothesis that desmin breakdown is an early and continuous process throughout VO. Male Sprague-Dawley rats had aortocaval fistula (ACF) or sham surgery and were examined 24 h and 4 and 12 wk later. Desmin/mitochondrial ultrastructure was examined by transmission electron microscopy (TEM) and immunohistochemistry (IHC). Protein and kinome analysis were performed in isolated cardiomyocytes, and desmin cleavage was assessed by mass spectrometry in left ventricular (LV) tissue. Echocardiography demonstrated a 40% decrease in the LV mass-to-volume ratio with spherical remodeling at 4 wk with ACF and LV systolic dysfunction at 12 wk. Starting at 24 h and continuing to 4 and 12 wk, with ACF there is TEM evidence of extensive mitochondrial clustering, IHC evidence of disorganization associated with desmin breakdown, and desmin protein cleavage verified by Western blot analysis and mass spectrometry. IHC results revealed that ACF cardiomyocytes at 4 and 12 wk had perinuclear translocation of αB-crystallin from the Z disk with increased α, β-unsaturated aldehyde 4-hydroxynonelal. Use of protein markers with verification by TUNEL staining and kinome analysis revealed an absence of cardiomyocyte apoptosis at 4 and 12 wk of ACF. Significant increases in protein indicators of mitophagy were countered by a sixfold increase in p62/sequestosome-1, which is indicative of an inability to complete autophagy. An early and continuous disruption of the desmin/mitochondrial architecture, accompanied by oxidative stress and inhibition of apoptosis and mitophagy, suggests its causal role in LV dilatation and systolic dysfunction in VO. NEW & NOTEWORTHY This study provides new evidence of early onset (24 h) and continuous (4-12 wk) desmin misarrangement and disruption of the normal sarcomeric and mitochondrial

  9. Heart Rate Variability in Nonlinear Rats with Different Orientation and Exploratory Activity in the Open Field.

    Science.gov (United States)

    Kur'yanova, E V; Teplyi, D L; Zhukova, Yu D; Zhukovina, N V

    2015-12-01

    The basic behavioral activity of nonlinear rats was evaluated from the sum of crossed peripheral and central squares and peripheral and central rearing postures in the open fi eld test. This index was low (30 episodes). Male rats with high score of orientation and exploratory activity were characterized by higher indexes of total heart rate variability than rats with low or intermediate activity. Specimens with a greater contribution of VLF waves into the total power spectrum of heart rate variability were shown to dominate among the rats with high behavioral activity. Our results are consistent with the notions of a suprasegmental nature of VLF waves.

  10. Modest weight loss in moderately overweight postmenopausal women improves heart rate variability

    DEFF Research Database (Denmark)

    Mouridsen, Mette Rauhe; Bendsen, Nathalie Tommerup; Astrup, Arne

    2013-01-01

    Purpose: To evaluate the effects of weight loss on heart rate (HR) and heart rate variability (HRV) parameters in overweight postmenopausal women. Design and Methods: Forty-nine overweight postmenopausal women with an average body mass index of 28.8 1.9 kg/m2 underwent a 12-week dietary weight......-to-normal intervals for each 5-min period (SDNNindex). Baseline body fat mass (FM%) and changes in body composition was determined by dual X-ray absorptiometry. Before and after the weight-loss period, total abdominal fat, intra-abdominal fat (IAAT), and subcutaneous abdominal fat (SCAT) were measured by single...

  11. Intermittent Auscultation for Intrapartum Fetal Heart Rate Surveillance: American College of Nurse-Midwives.

    Science.gov (United States)

    2015-01-01

    Fetal heart rate surveillance is a standard component of intrapartum care. The fetal heart rate can be evaluated using intermittent auscultation or electronic fetal monitoring. Research that has compared these 2 strategies found them to be equivalent with respect to long-term neonatal outcomes. The purpose of this clinical bulletin by the American College of Nurse-Midwives is to review the evidence for use of intermittent auscultation and provide recommendations for intermittent auscultation technique, interpretation, and documentation. © 2015 by the American College of Nurse-Midwives.

  12. Heart rate response to a climber’s fall in sport climbing

    OpenAIRE

    Chaloupsky, David

    2015-01-01

    The research deals with response of heart rate to a climber’s simulated fall in a leading position when indoor climbing. Heart rate of climbers was recorded during ascents of an overhanging route in the leading position, to the given point high above the ground, followed by falling into the last protection. The length of the free fall was defined by the place of the last belay anchor, which was at the height of climber’s ankles. The length of the fall was about two meters of free fall plus th...

  13. Heart Rate-Determined Physical Activity In New Zealand School Children: A Cross- Sectional Study

    OpenAIRE

    Michael J. Hamlin; Mick Grimley; Vicki Cowley; Chris D. Price; Jill M. Hargreaves; Jenny J. Ross

    2011-01-01

    The aim of this study was to examine current levels of physical activity determined via heart rate monitoring. A total of 176 children (85 boys, 91 girls) aged 5-13 years wore sealed Polar heart rate monitors for at least 10 hours per day on at least 3 days. Mean daily minutes of moderate to vigorous-intensity physical activity was 65 ± 43 (mean ± SD) for boys and 54 ± 37 for girls. Daily minutes of vigorous-intensity activity was 31 ± 24 and 24 ± 21 for boys and girls respectively. Significa...

  14. Effect of Heart rate on Basketball Three-Point Shot Accuracy

    OpenAIRE

    Luca P. Ardigò; Goran Kuvacic; Antonio D. Iacono; Giacomo Dascanio; Johnny Padulo; Johnny Padulo

    2018-01-01

    The three-point shot (3S) is a fundamental basketball skill used frequently during a game, and is often a main determinant of the final result. The aim of the study was to investigate the effect of different metabolic conditions, in terms of heart rates, on 3S accuracy (3S%) in 24 male (Under 17) basketball players (age 16.3 ± 0.6 yrs). 3S performance was specifically investigated at different heart rates. All sessions consisted of 10 consecutive 3Ss from five different significant field spot...

  15. Effects of imipramine of the orthostatic changes in blood pressure, heart rate and plasma catecholamines

    DEFF Research Database (Denmark)

    Nielsen, J R; Johansen, Torben; Arentoft, A

    1983-01-01

    The effect of imipramine on the orthostatic changes in heart rate, blood pressure and plasma catecholamines were examined in six healthy male subjects on two occasions on high sodium balance (Na+ excretion greater than 120 mmol per day) and on low sodium balance (Na+ excretion less than 110 mmol...... per day), respectively. Orthostatic tests were carried out before and 2 h after ingestion of 150 mg imipramine hydrochloride. Imipramine caused a moderate increase in supine systolic blood pressure, and a pronounced increase in the rise in heart rate, when the subjects assumed erect position...

  16. Can accelerometry data improve estimates of heart rate variability from wrist pulse PPG sensors?*

    Science.gov (United States)

    Kos, Maciej; Li, Xuan; Khaghani-Far, Iman; Gordon, Christine M.; Pavel, Misha; Jimison Member, Holly B.

    2018-01-01

    A key prerequisite for precision medicine is the ability to assess metrics of human behavior objectively, unobtrusively and continuously. This capability serves as a framework for the optimization of tailored, just-in-time precision health interventions. Mobile unobtrusive physiological sensors, an important prerequisite for realizing this vision, show promise in implementing this quality of physiological data collection. However, first we must trust the collected data. In this paper, we present a novel approach to improving heart rate estimates from wrist pulse photoplethysmography (PPG) sensors. We also discuss the impact of sensor movement on the veracity of collected heart rate data. PMID:29060185

  17. Can accelerometry data improve estimates of heart rate variability from wrist pulse PPG sensors?

    Science.gov (United States)

    Kos, Maciej; Xuan Li; Khaghani-Far, Iman; Gordon, Christine M; Pavel, Misha; Jimison, Holly B

    2017-07-01

    A key prerequisite for precision medicine is the ability to assess metrics of human behavior objectively, unobtrusively and continuously. This capability serves as a framework for the optimization of tailored, just-in-time precision health interventions. Mobile unobtrusive physiological sensors, an important prerequisite for realizing this vision, show promise in implementing this quality of physiological data collection. However, first we must trust the collected data. In this paper, we present a novel approach to improving heart rate estimates from wrist pulse photoplethysmography (PPG) sensors. We also discuss the impact of sensor movement on the veracity of collected heart rate data.

  18. Hopfield neural network and optical fiber sensor as intelligent heart rate monitor

    Science.gov (United States)

    Mutter, Kussay Nugamesh

    2018-01-01

    This paper presents a design and fabrication of an intelligent fiber-optic sensor used for examining and monitoring heart rate activity. It is found in the literature that the use of fiber sensors as heart rate sensor is widely studied. However, the use of smart sensors based on Hopfield neural networks is very low. In this work, the sensor is a three fibers without cladding of about 1 cm, fed by laser light of 1550 nm of wavelength. The sensing portions are mounted with a micro sensitive diaphragm to transfer the pulse pressure on the left radial wrist. The influenced light intensity will be detected by a three photodetectors as inputs into the Hopfield neural network algorithm. The latter is a singlelayer auto-associative memory structure with a same input and output layers. The prior training weights are stored in the net memory for the standard recorded normal heart rate signals. The sensors' heads work on the reflection intensity basis. The novelty here is that the sensor uses a pulse pressure and Hopfield neural network in an integrity approach. The results showed a significant output measurements of heart rate and counting with a plausible error rate.

  19. Analyses of Heart Rate, Respiration and Cardiorespiratory Coupling in Patients with Schizophrenia

    Directory of Open Access Journals (Sweden)

    Steffen Schulz

    2015-01-01

    Full Text Available Schizophrenia is a severe mental disorder associated with a significantly increased cardiovascular mortality rate. However, the underlying mechanisms leading to this cardiovascular disease (CVD are not fully known. Therefore, the objective of this study was to characterize the cardiorespiratory influence by investigating heart rate, respiration and the causal strength and direction of cardiorespiratory coupling (CRC, based mainly on entropy measures. We investigated 23 non-medicated patients with schizophrenia (SZ, comparing them to 23 age- and gender-matched healthy controls (CO. A significantly reduced complexity was found for the heart rate and a significantly increased complexity in respiration and CRC in SZ patients when compared to corresponding measurements from CO (p < 0.001. CRC analyses revealed a clear coupling, with a driver-responder relationship from respiration to heart rate in SZ patients. Moreover, a slight driver-responder relationship from heart rate to respiration could be recognized. These findings lead to the assumption that SZ should be considered to be a high-risk group for CVD. We hypothesize that the varying cardiorespiratory regulation contributes to the increased risk for cardiac mortality. Therefore, regular monitoring of the cardiorespiratory status of SZ is suggested to identify autonomic regulation impairment at an early stage—to develop timely and effective treatment and intervention strategies.

  20. Endogenous Pain Modulation: Association with Resting Heart Rate Variability and Negative Affectivity.

    Science.gov (United States)

    Van Den Houte, Maaike; Van Oudenhove, Lukas; Bogaerts, Katleen; Van Diest, Ilse; Van den Bergh, Omer

    2017-07-21

    Several chronic pain syndromes are characterized by deficient endogenous pain modulation as well as elevated negative affectivity and reduced resting heart rate variability. In order to elucidate the relationships between these characteristics, we investigated whether negative affectivity and heart rate variability are associated with endogenous pain modulation in a healthy population. An offset analgesia paradigm with noxious thermal stimulation calibrated to the individual's pain threshold was used to measure endogenous pain modulation magnitude in 63 healthy individuals. Pain ratings during constant noxious heat stimulation to the arm (15 seconds) were compared with ratings during noxious stimulation comprising a 1 °C rise and return of temperature to the initial level (offset trials, 15 seconds). Offset analgesia was defined as the reduction in pain following the 1 °C decrease relative to pain at the same time point during continuous heat stimulation. Evidence for an offset analgesia effect could only be found when noxious stimulation intensity (and, hence, the individual's pain threshold) was intermediate (46 °C or 47 °C). Offset analgesia magnitude was also moderated by resting heart rate variability: a small but significant offset effect was found in participants with high but not low heart rate variability. Negative affectivity was not related to offset analgesia magnitude. These results indicate that resting heart rate variability (HRV) is related to endogenous pain modulation (EPM) in a healthy population. Future research should focus on clarifying the causal relationship between HRV and EPM and chronic pain by using longitudinal study designs. © 2017 American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

  1. Association between smoking and heart rate variability among individuals with depression.

    Science.gov (United States)

    Harte, Christopher B; Liverant, Gabrielle I; Sloan, Denise M; Kamholz, Barbara W; Rosebrock, Laina E; Fava, Maurizio; Kaplan, Gary B

    2013-08-01

    Both depression and smoking have been independently associated with lower heart rate variability (HRV), suggesting dysregulation of cardiac autonomic function. However, no studies have systematically explored the effects of smoking on HRV among depressed patients. This study examined differences in HRV based on smoking status among depressed individuals. Electrophysiological data were examined among 77 adult outpatients without a history of myocardial infarction, who met criteria for major depressive disorder or dysthymia. Frequency domain [low frequency (LF), high frequency (HF), LF/HF ratio, respiratory sinus arrhythmia (RSA)] parameters of HRV, and heart rate and inter-beat interval (IBI) data were compared between depressed smokers (n = 34) and depressed nonsmokers (n = 44). After controlling for covariates, depressed smokers, compared to depressed nonsmokers, displayed significantly lower LF, HF, and RSA. Among depressed patients, smoking is associated with significantly lower HRV, indicating dysregulated autonomic modulation of the heart.

  2. Incident solar radiation and coronary heart disease mortality rates in Europe

    International Nuclear Information System (INIS)

    Wong, Alfred

    2008-01-01

    The reported low mortality rate from coronary heart disease in Portugal, Spain, Italy, Greece, and France, to a lesser extent, has been attributed in numerous nutritional studies to the consumption of a Mediterranean-type diet. There are still many unresolved issues about the direct causal effect of the Mediterranean dietary regime on low incidence of coronary heart disease. An analysis of coronary heart disease mortality rates in Europe from a latitudinal gradient perspective has shown to have a close correlation to incident solar radiation. It is surmised that the resulting increased in situ biosynthesis of Vitamin D 3 could be the critical missing confounder in the analysis of the beneficial health outcome of the Mediterranean diet

  3. Heart Rate Variability in Cavalier King Charles Spaniels with Different Degree of Myxomatous Mitral Valve Disease

    DEFF Research Database (Denmark)

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

    2010-01-01

    Sciences, University of Copenhagen, Frederiksberg, Denmark, 2Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden; and 3Novo Nordic A/S, Maaloev, Denmark. Introduction: Modulation of heart rate by the autonomic nervous system can indirectly be measured by heart rate...... variability (HRV). Reduced HRV is seen in dogs with heart failure secondary to myxomatous mitral valve disease (MMVD). However, HRV is suggested to increase with disease progression in dogs with early stages of MMVD. Comparable results are found in people with primary mitral valve prolapse, a disease...... resembling canine MMVD. Aim: To associate progression of MMVD in dogs with time and frequency domain HRV, analysed from 24-hour electrocardiography. Materials and Methods: Eighty-one Cavalier King Charles Spaniels (CKCS) were examined by echocardiography and 24-hour electrocardiography. CKCS were divided...

  4. The role of abnormal fetal heart rate in scheduling chorionic villus sampling.

    Science.gov (United States)

    Yagel, S; Anteby, E; Ron, M; Hochner-Celnikier, D; Achiron, R

    1992-09-01

    To assess the value of fetal heart rate (FHR) measurements in predicting spontaneous fetal loss in pregnancies scheduled for chorionic villus sampling (CVS). A prospective descriptive study. Two hospital departments of obstetrics and gynaecology in Israel. 114 women between 9 and 11 weeks gestation scheduled for chorionic villus sampling (CVS). Fetal heart rate was measured by transvaginal Doppler ultrasound and compared with a monogram established from 75 fetuses. Whenever a normal FHR was recorded, CVS was performed immediately. 106 women had a normal FHR and underwent CVS; two of these pregnancies ended in miscarriage. In five pregnancies no fetal heart beats could be identified and fetal death was diagnosed. In three pregnancies an abnormal FHR was recorded and CVS was postponed; all three pregnancies ended in miscarriage within 2 weeks. Determination of FHR correlated with crown-rump length could be useful in predicting spontaneous miscarriage before performing any invasive procedure late in the first trimester.

  5. [Evaluation of heart impact in the 100 m extreme intensity sport using near-infrared non-invasive muscle oxygen detecting device and sports heart rate detection technology].

    Science.gov (United States)

    Wang, Pei-Yong; Long, Fei-Xiao; Fu, Lan-Ying; Li, Yue; Ding, Hai-Shu; Qu, An-Lian; Zhou, Xiao-Ping

    2010-02-01

    Using continuous two wavelength near-infrared technology to detect the variation in the consistency of oxygen hemoglobin in the muscle and the sports heart rate wireless real time collection technology, we devised the real time muscle tissue oxygenation and instantaneous heart rate experiment scheme and implemented it for the process of the 100 m run with two parameters given simultaneously. The experiment shows that the concentration of the oxygen hemoglobin in the muscle tissue continues decreasing after the end of the 100 m run, and the time interval between the moment when the concentration of the oxygen hemoglobin attains the minimum value and the moment when the athletes finish the 100 m run is (6.65 +/- 1.10) sec; while the heart rate continues increasing after the end of the 100 m run, and the time interval between the moment when the heart rate attains the maximum value and the moment when the athletes finish the 100 m run is (8.00 +/- 1.57) sec. The results show that the two wavelength near-infrared tissue oxygenation detection technology and the sports heart rate real time collection equipment can accurately measure the sports tissue oxygenation and the heart rate in the extreme intensity sport, and reveal the process of muscle oxygen transportation and consumption and its dynamic character with the heart rate in the extreme intensity sport.

  6. Heart rate reveals torpor at high body temperatures in lowland tropical free-tailed bats.

    Science.gov (United States)

    O'Mara, M Teague; Rikker, Sebastian; Wikelski, Martin; Ter Maat, Andries; Pollock, Henry S; Dechmann, Dina K N

    2017-12-01

    Reduction in metabolic rate and body temperature is a common strategy for small endotherms to save energy. The daily reduction in metabolic rate and heterothermy, or torpor, is particularly pronounced in regions with a large variation in daily ambient temperature. This applies most strongly in temperate bat species (order Chiroptera), but it is less clear how tropical bats save energy if ambient temperatures remain high. However, many subtropical and tropical species use some daily heterothermy on cool days. We recorded the heart rate and the body temperature of free-ranging Pallas' mastiff bats ( Molossus molossus ) in Gamboa, Panamá, and showed that these individuals have low field metabolic rates across a wide range of body temperatures that conform to high ambient temperature. Importantly, low metabolic rates in controlled respirometry trials were best predicted by heart rate, and not body temperature . Molossus molossus enter torpor-like states characterized by low metabolic rate and heart rates at body temperatures of 32°C, and thermoconform across a range of temperatures. Flexible metabolic strategies may be far more common in tropical endotherms than currently known.

  7. 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

  8. C-reactive protein, heart rate variability and prognosis in community subjects with no apparent heart disease

    DEFF Research Database (Denmark)

    Sajadieh, A; Nielsen, OW; Rasmussen, Verner

    2006-01-01

    OBJECTIVES: Increased C-reactive protein (CRP) and reduced heart rate variability (HRV) both indicate poor prognosis. An inverse association between HRV and CRP has been reported, suggesting an interaction between inflammatory and autonomic systems. However, the prognostic impact of this interact...... of four HRV measures were significantly associated with increased rate of death or myocardial infarction. In a Cox model with CRP >or=2.5 microg mL(-1), standard deviation for the mean value of the time between normal complexes...... examinations, and 24-h Holter monitoring. Four time domain measures of HRV were studied. All were prospectively followed for up to 5 years. RESULTS: Mean age was 64 years (55-75). During the follow-up, 46 total deaths and 11 cases of definite acute myocardial infarction were observed. Both CRP and three...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-11-01

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

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

    International Nuclear Information System (INIS)

    Li, Shou-lin; Ikeda, Jun; Takita, Tamotsu; Sekiguchi, Yohei; Demachi, Jun; Chikama, Hisao; Goto, Atsushi; Shirato, Kunio

    1998-01-01

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

  11. Peculiarities of vegetative regulation of heart rate in wrestlers of different age groups

    Directory of Open Access Journals (Sweden)

    E.B. Zapovitriana

    2015-04-01

    Full Text Available Purpose : the aim of the work was to study the characteristics of vegetative regulation of cardiac rhythm in athletes of high qualification of different age groups. Material : 26 wrestlers of Greco-Roman style of high qualification aged 19-34 years old were studied. Vegetative regulation was assessed by statistical analysis of heart rate variability using cardiac monitors «Polar RS800CX». Results : the results showed that the wrestlers of older age group has a greater level of tension of regulation of heart rhythm for compared with young athletes. This is confirmed by the reduced values of the mean square deviation RR- intervals and triangular index. According to the results of spectral analysis of cardio revealed activation of parasympathetic tone of the autonomic regulation of the heart rhythm of wrestlers in older age group, compared with young athletes. The increase of tension of regulation of heart rate in the wrestlers of older age group accompanied by a slowdown of aperiodic and periodic oscillations of cardio intervals. Conclusions: the high level of tension of regulation of heart rhythm in older wrestlers group (26-34 accompanied by the activation of neurohumoral centers and parasympathetic link of vegetative nervous system.

  12. Onset of decreased heart work is correlated with increased heart rate and shortened QT interval in high-carbohydrate fed overweight rats.

    Science.gov (United States)

    Durak, Aysegul; Olgar, Yusuf; Tuncay, Erkan; Karaomerlioglu, Irem; Kayki Mutlu, Gizem; Arioglu Inan, Ebru; Altan, Vecdi Melih; Turan, Belma

    2017-11-01

    Mechanical activity of the heart is adversely affected in metabolic syndrome (MetS) characterized by increased body mass and marked insulin resistance. Herein, we examined the effects of high carbohydrate intake on cardiac function abnormalities by evaluating in situ heart work, heart rate, and electrocardiograms (ECGs) in rats. MetS was induced in male Wistar rats by adding 32% sucrose to drinking water for 22-24 weeks and was confirmed by insulin resistance, increased body weight, increased blood glucose and serum insulin, and increased systolic and diastolic blood pressures in addition to significant loss of left ventricular integrity and increased connective tissue around myofibrils. Analysis of in situ ECG recordings showed a markedly shortened QT interval and decreased QRS amplitude with increased heart rate. We also observed increased oxidative stress and decreased antioxidant defense characterized by decreases in serum total thiol level and attenuated paraoxonase and arylesterase activities. Our data indicate that increased heart rate and a shortened QT interval concomitant with higher left ventricular developed pressure in response to β-adrenoreceptor stimulation as a result of less cyclic AMP release could be regarded as a natural compensation mechanism in overweight rats with MetS. In addition to the persistent insulin resistance and obesity associated with MetS, one should consider the decreased heart work, increased heart rate, and shortened QT interval associated with high carbohydrate intake, which may have more deleterious effects on the mammalian heart.

  13. 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 pre