Sample records for target heart rates
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Using Target Heart-Rate Zones in Your Class
ERIC Educational Resources Information Center
Gilbert, Jennie A.
2005-01-01
Should teachers teach the calculation of target heart rate to students? And when is it appropriate to engage students in the attainment of these heart rates during physical education class activities? The answers to these questions are not easy. One might be tempted to state a simple yes or no and to identify a specific age to begin using training…
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Constant-load versus heart rate-targeted exercise - Responses of systolic intervals
NASA Technical Reports Server (NTRS)
Lance, V. Q.; Spodick, D. H.
1975-01-01
Various systolic intervals were measured prior to and during heart rate-targeted bicycle ergometer exercise. There were striking similarities within each matched exercise set for Q-Im, isovolumetric contraction time, preejection period (PEP), and PEP/left ventricular ejection time (LVET). LVET was significantly shorter for rate-targeted exercise. It is concluded that either constant-load or rate-targeted bicycle ergometry may be used with the choice of method determined by the purpose of the protocol, and that systolic intervals (except LVET) should not be much altered owing to the method chosen.
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A comparison between computer-controlled and set work rate exercise based on target heart rate
NASA Technical Reports Server (NTRS)
Pratt, Wanda M.; Siconolfi, Steven F.; Webster, Laurie; Hayes, Judith C.; Mazzocca, Augustus D.; Harris, Bernard A., Jr.
1991-01-01
Two methods are compared for observing the heart rate (HR), metabolic equivalents, and time in target HR zone (defined as the target HR + or - 5 bpm) during 20 min of exercise at a prescribed intensity of the maximum working capacity. In one method, called set-work rate exercise, the information from a graded exercise test is used to select a target HR and to calculate a corresponding constant work rate that should induce the desired HR. In the other method, the work rate is controlled by a computer algorithm to achieve and maintain a prescribed target HR. It is shown that computer-controlled exercise is an effective alternative to the traditional set work rate exercise, particularly when tight control of cardiovascular responses is necessary.
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Casillas, Jean-Marie; Joussain, Charles; Gremeaux, Vincent; Hannequin, Armelle; Rapin, Amandine; Laurent, Yves; Benaïm, Charles
2015-02-01
To develop a new predictive model of maximal heart rate based on two walking tests at different speeds (comfortable and brisk walking) as an alternative to a cardiopulmonary exercise test during cardiac rehabilitation. Evaluation of a clinical assessment tool. A Cardiac Rehabilitation Department in France. A total of 148 patients (133 men), mean age of 59 ±9 years, at the end of an outpatient cardiac rehabilitation programme. Patients successively performed a 6-minute walk test, a 200 m fast-walk test (200mFWT), and a cardiopulmonary exercise test, with measure of heart rate at the end of each test. An all-possible regression procedure was used to determine the best predictive regression models of maximal heart rate. The best model was compared with the Fox equation in term of predictive error of maximal heart rate using the paired t-test. Results of the two walking tests correlated significantly with maximal heart rate determined during the cardiopulmonary exercise test, whereas anthropometric parameters and resting heart rate did not. The simplified predictive model with the most acceptable mean error was: maximal heart rate = 130 - 0.6 × age + 0.3 × HR200mFWT (R(2) = 0.24). This model was superior to the Fox formula (R(2) = 0.138). The relationship between training target heart rate calculated from measured reserve heart rate and that established using this predictive model was statistically significant (r = 0.528, p < 10(-6)). A formula combining heart rate measured during a safe simple fast walk test and age is more efficient than an equation only including age to predict maximal heart rate and training target heart rate. © The Author(s) 2014.
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Office and 24-hour heart rate and target organ damage in hypertensive patients
2012-01-01
Background We investigated the association between heart rate and its variability with the parameters that assess vascular, renal and cardiac target organ damage. Methods A cross-sectional study was performed including a consecutive sample of 360 hypertensive patients without heart rate lowering drugs (aged 56 ± 11 years, 64.2% male). Heart rate (HR) and its standard deviation (HRV) in clinical and 24-hour ambulatory monitoring were evaluated. Renal damage was assessed by glomerular filtration rate and albumin/creatinine ratio; vascular damage by carotid intima-media thickness and ankle/brachial index; and cardiac damage by the Cornell voltage-duration product and left ventricular mass index. Results There was a positive correlation between ambulatory, but not clinical, heart rate and its standard deviation with glomerular filtration rate, and a negative correlation with carotid intima-media thickness, and night/day ratio of systolic and diastolic blood pressure. There was no correlation with albumin/creatinine ratio, ankle/brachial index, Cornell voltage-duration product or left ventricular mass index. In the multiple linear regression analysis, after adjusting for age, the association of glomerular filtration rate and intima-media thickness with ambulatory heart rate and its standard deviation was lost. According to the logistic regression analysis, the predictors of any target organ damage were age (OR = 1.034 and 1.033) and night/day systolic blood pressure ratio (OR = 1.425 and 1.512). Neither 24 HR nor 24 HRV reached statistical significance. Conclusions High ambulatory heart rate and its variability, but not clinical HR, are associated with decreased carotid intima-media thickness and a higher glomerular filtration rate, although this is lost after adjusting for age. Trial Registration ClinicalTrials.gov: NCT01325064 PMID:22439900
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Corletto, Anna; Fröhlich, Hanna; Täger, Tobias; Hochadel, Matthias; Zahn, Ralf; Kilkowski, Caroline; Winkler, Ralph; Senges, Jochen; Katus, Hugo A; Frankenstein, Lutz
2018-05-17
Beta blockers improve survival in patients with chronic systolic heart failure (CHF). Whether physicians should aim for target dose, target heart rate (HR), or both is still under debate. We identified 1,669 patients with systolic CHF due to ischemic heart disease or idiopathic dilated cardiomyopathy from the University Hospital Heidelberg and the Clinic of Ludwigshafen, Germany. All patients were treated with an angiotensin converting enzyme inhibitor or angiotensin receptor blocker and had a history of CHF known for at least 6 months. Target dose was defined as treatment with ≥ 95% of the respective published guideline-recommended dose. Target HR was defined as 51-69 bpm. All-cause mortality during the median follow-up of 42.8 months was analysed with respect to beta blocker dosing and resting HR. 201 (12%) patients met the dose target (group A), 285 (17.1%) met the HR target (group B), 627 (37.6%) met no target (group C), and 556 (33.3%) did not receive beta blockers (Group D). 5-year mortality was 23.7, 22.7, 37.6, and 55.6% for group A, B, C, and D, respectively (p < 0.001). Survival for group A patients with a HR ≥ 70 bpm was 28.8% but 14.8% if HR was 50-70 bpm (p = 0.054). Achieving guidelines recommended beta blocker dose or to HR control has a similar positive impact on survival. When on target dose, supplemental HR control additionally improves survival.
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Role of ivabradine and heart rate lowering in chronic heart failure: guideline update.
Chow, Sheryl L; Page, Robert Lee; Depre, Christophe
2018-06-14
This review summarizes the current management of heart failure (HF) in patients with reduced ejection fraction and the potential role of heart rate lowering agents in select populations, as recommended in the updated guidelines. Areas covered: PubMed was searched for studies that evaluated the role of heart rate lowering or ivabradine in HF management. Expert commentary: Targeting heart rate may offer benefit when added to renin-angiotensin aldosterone antagonists, and beta-blockers. Ivabradine is a heart rate lowering agent that acts on the funny current (I f ) in the sinoatrial node, thereby reducing heart rate without directly affecting cardiac contraction and relaxation. Clinical data from a phase 3 trial demonstrated that ivabradine reduced the composite endpoint of cardiovascular death or hospital admission for worsening systolic HF, while maintaining an acceptable safety profile in patients receiving standard of care therapy. These data, in addition to more recently published guidelines, suggest ivabradine as a promising new treatment option for lowering heart rate after optimizing standard therapy in select patients with chronic HF.
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Ambrosetti, Marco; Scardina, Giuseppe; Favretto, Giuseppe; Temporelli, Pier Luigi; Faggiano, Pompilio Massimo; Greco, Cesare; Pedretti, Roberto Franco
2017-03-01
For patients with stable coronary artery disease (SCAD), either after hospitalization for acute cardiac events or in the chronic phase, comprehensive treatment programs should be devoted to: (i) reducing mortality and major adverse cardiovascular events, (ii) reducing the ischemic burden and related symptoms, and (iii) increasing exercise capacity and quality of life.Heart rate (HR) has demonstrated to have prognostic value and patients beyond the limit of 70 bpm display increased risk of all the above adverse outcomes, even after adjustment for parameters such as the extension of myocardial infarction and the presence of heart failure. It is well known that a sustained HR elevation may contribute to the pathogenesis of SCAD, being the likelihood of developing ischemia, plaque instability, trigger for arrhythmias, increased vascular oxidative stress, and endothelial dysfunction the mechanisms resulting in this effect. Moreover, high HR could promote chronotropic incompetence, leading to functional disability and reduced quality of life.Despite the strong relationship between HR and prognosis, there is heterogeneity among current guidelines in considering HR as a formal therapeutic target for secondary prevention in SCAD, as far as the cut-off limit. This expert opinion document considered major trials and observational registries in the modern treatment era with beta-blockers and ivabradine, suggesting that an adequate HR control could represent a target for (i), (ii), and (iii) therapeutic goals in SCAD patients with systolic dysfunction (with major evidence for reduced left ventricular ejection fraction <40%), and a target for (ii) and (iii) goals in SCAD patients with preserved left ventricular ejection fraction. The defined cut-off limit is 70 bpm. To date, there is room for improvement of HR control, since in contemporary SCAD patients HR values <70 bpm are present in less than half of cases, even in the vulnerable phase after an acute coronary syndrome.
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NASA Technical Reports Server (NTRS)
1990-01-01
Under a NASA grant, Dr. Robert M. Davis and Dr. William M. Portnoy came up with a new type of electrocardiographic electrode that would enable long term use on astronauts. Their invention was an insulated capacitive electrode constructed of a thin dielectric film. NASA subsequently licensed the electrode technology to Richard Charnitski, inventor of the VersaClimber, who founded Heart Rate, Inc., to further develop and manufacture personal heart monitors and to produce exercise machines using the technology for the physical fitness, medical and home markets. Same technology is on both the Home and Institutional Model VersaClimbers. On the Home Model an infrared heart beat transmitter is worn under exercise clothing. Transmitted heart rate is used to control the work intensity on the VersaClimber using the heart rate as the speedometer of the exercise. This offers advantages to a full range of users from the cardiac rehab patient to the high level physical conditioning of elite athletes. The company manufactures and markets five models of the 1*2*3 HEART RATE monitors that are used wherever people exercise to accurately monitor their heart rate. Company is developing a talking heart rate monitor that works with portable headset radios. A version of the heart beat transmitter will be available to the manufacturers of other aerobic exercise machines.
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Cygankiewicz, Iwona
2013-01-01
Heart rate turbulence (HRT) is a baroreflex-mediated biphasic reaction of heart rate in response to premature ventricular beats. Heart rate turbulence is quantified by: turbulence onset (TO) reflecting the initial acceleration of heart rate following premature beat and turbulence slope (TS) describing subsequent deceleration of heart rate. Abnormal HRT identifies patients with autonomic dysfunction or impaired baroreflex sensitivity due to variety of disorders, but also may reflect changes in autonomic nervous system induced by different therapeutic modalities such as drugs, revascularization, or cardiac resynchronization therapy. More importantly, impaired HRT has been shown to identify patients at high risk of all-cause mortality and sudden death, particularly in postinfarction and congestive heart failure patients. It should be emphasized that abnormal HRT has a well-established role in stratification of postinfarction and heart failure patients with relatively preserved left ventricular ejection fraction. The ongoing clinical trials will document whether HRT can be used to guide implantation of cardioverter-defibrillators in this subset of patients, not covered yet by ICD guidelines. This review focuses on the current state-of-the-art knowledge regarding clinical significance of HRT in detection of autonomic dysfunction and regarding the prognostic significance of this parameter in predicting all-cause mortality and sudden death. © 2013.
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Heart-Rate and Breath-Rate Monitor
NASA Technical Reports Server (NTRS)
Cooper, T. G.
1983-01-01
Circuit requiring only four integrated circuits (IC's) measures both heart rate and breath rate. Phase-locked loops lock on heart-rate and respiration-rate input signals. Each loop IC contains two phase comparators. Positive-edge-triggered circuit used in making monitors insensitive to dutycycle variations.
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Heart rate differentiates urgency and emergency in hypertensive crisis.
Al Bannay, Rashed; Böhm, Michael; Husain, Aysha
2013-08-01
To study the clinical significance of presenting blood pressure parameters and heart rate in patients with hypertensive crisis. In patients admitted with hypertensive crisis between January 2011 and May 2011, demography, mode of presentation, co-morbidities, blood pressure readings, and heart rate at presentation were documented. Further clustering of hypertensive crisis into emergency or urgency was based on the presence or absence of target organ involvement. The relationship between blood pressure parameters, heart rate, and other variables was analyzed. 189 patients in sinus rhythm were enrolled in this pilot study. The rate of hypertensive urgency was 56 %, whereas the rate of hypertensive emergency was 44 %, respectively. Subjects with hypertensive emergency had a higher mean heart rate (93 ± 22.7 bpm) than those with urgency (81 ± 11.5 bpm) (P = 0.015). Women had higher heart rates (92 ± 18.5 bpm) than men (86 ± 17.6 bpm) (P = 0.014). Heart rates below 100 bpm had a specificity of 94 %, classifying patients as hypertensive urgency. Tachycardia had a powerful statistical association with hypertensive left ventricular failure (P < 0.0001). Other hemodynamic parameters, including systolic blood pressure, diastolic blood pressure, pulse pressure, and mean blood pressure relates neither to urgency nor to emergency. Diabetic patients with HBA1c levels of more than 53 mmol/mol had a heart rate of more than 100 bpm (P = 0.015) during hypertensive crisis. Normal heart rate is characteristic of hypertensive urgency. Tachycardia in this setting is an ominous sign and denotes hypertensive complications in particular left ventricular failure. Among diabetics, elevated heart rate is associated with poor glycemic control.
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Monfredi, Oliver; Lyashkov, Alexey E; Johnsen, Anne-Berit; Inada, Shin; Schneider, Heiko; Wang, Ruoxi; Nirmalan, Mahesh; Wisloff, Ulrik; Maltsev, Victor A; Lakatta, Edward G; Zhang, Henggui; Boyett, Mark R
2014-01-01
Heart rate variability (beat-to-beat changes in the RR interval) has attracted considerable attention over the last 30+ years (PubMed currently lists >17,000 publications). Clinically, a decrease in heart rate variability is correlated to higher morbidity and mortality in diverse conditions, from heart disease to foetal distress. It is usually attributed to fluctuation in cardiac autonomic nerve activity. We calculated heart rate variability parameters from a variety of cardiac preparations (including humans, living animals, Langendorff-perfused heart and single sinoatrial nodal cell) in diverse species, combining this with data from previously published papers. We show that regardless of conditions, there is a universal exponential decay-like relationship between heart rate variability and heart rate. Using two biophysical models, we develop a theory for this, and confirm that heart rate variability is primarily dependent on heart rate and cannot be used in any simple way to assess autonomic nerve activity to the heart. We suggest that the correlation between a change in heart rate variability and altered morbidity and mortality is substantially attributable to the concurrent change in heart rate. This calls for re-evaluation of the findings from many papers that have not adjusted properly or at all for heart rate differences when comparing heart rate variability in multiple circumstances. PMID:25225208
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Heart rate monitoring mobile applications
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. PMID:28293594
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Heart rate monitoring mobile applications.
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.
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Graham, Rebecca A; Scott, Brandon G; Weems, Carl F
2017-05-01
Adolescence is a potentially important time in the development of emotion regulation and parenting behaviors may play a role. We examined associations among parenting behaviors, parent resting heart rate variability, adolescent resting heart rate variability and parenting behaviors as moderators of the association between parent and adolescent resting heart rate variability. Ninety-seven youth (11-17 years; 49.5 % female; 34 % African American, 37.1 % Euro-American, 22.6 % other/mixed ethnic background, and 7.2 % Hispanic) and their parents (n = 81) completed a physiological assessment and questionnaires assessing parenting behaviors. Inconsistent discipline and corporal punishment were negatively associated with adolescent resting heart rate variability, while positive parenting and parental involvement were positively associated. Inconsistent discipline and parental involvement moderated the relationship between parent and adolescent resting heart rate variability. The findings provide evidence for a role of parenting behaviors in shaping the development of adolescent resting heart rate variability with inconsistent discipline and parental involvement potentially influencing the entrainment of resting heart rate variability in parents and their children.
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Optimization of pharmacotherapy in chronic heart failure: is heart rate adequately addressed?
Franke, Jennifer; Wolter, Jan Sebastian; Meme, Lillian; Keppler, Jeannette; Tschierschke, Ramon; Katus, Hugo A; Zugck, Christian
2013-01-01
The aim of the study is to evaluate the use of beta-blockers in chronic heart failure (CHF) and the extent of heart rate reduction achieved in clinical practice and to determine differences in outcome of patients who fulfilled select inclusion criteria of the SHIFT study according to resting heart rate modulated by beta-blocker therapy. We evaluated an all-comer population of our dedicated CHF outpatient clinic between 2006 and 2010. For inclusion, individually optimized doses of guideline-recommended pharmacotherapy including beta-blockers had to be maintained for at least 3 months and routine follow-up performed at our outpatient CHF-clinic thereafter. Treatment dosages of beta-blockers, and demographic and clinical profiles including resting heart rate were assessed. The outcome of patients who fulfilled select inclusion criteria of the SHIFT study (left-ventricular ejection fraction (LVEF) ≤35 %, sinus rhythm, NYHA II-IV) and were followed-up for at least 1 year was stratified according to resting heart rates: ≥75 versus <75 bpm and ≥70 versus <70 bpm. The composite primary endpoint was defined as all-cause death or hospital admission for worsening heart failure during 12-month follow-up. In total, 3,181 patients were assessed in regard to treatment dosages of beta-blockers, and demographic and clinical profiles including resting heart rate. Of the overall studied population, 443 patients fulfilled all inclusion criteria and entered outcome analysis. Median observation time of survivors was 27.5 months with 1,039.7 observation-years in total. Up-titration to at least half the evidence-based target dose of beta-blockers was achieved in 69 % and full up-titration in 29 % of these patients. Patients with increased heart rates were younger, more often male, exhibited a higher NYHA functional class and lower LVEF. The primary endpoint occurred in 21 % of patients in the ≥70 bpm group versus 9 % of patients in the group with heart rates <70
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Heart failure—potential new targets for therapy
Nabeebaccus, Adam; Zheng, Sean; Shah, Ajay M.
2016-01-01
Abstract Introduction/background Heart failure is a major cause of cardiovascular morbidity and mortality. This review covers current heart failure treatment guidelines, emerging therapies that are undergoing clinical trial, and potential new therapeutic targets arising from basic science advances. Sources of data A non-systematic search of MEDLINE was carried out. International guidelines and relevant reviews were searched for additional articles. Areas of agreement Angiotensin-converting enzyme inhibitors and beta-blockers are first line treatments for chronic heart failure with reduced left ventricular function. Areas of controversy Treatment strategies to improve mortality in heart failure with preserved left ventricular function are unclear. Growing points Many novel therapies are being tested for clinical efficacy in heart failure, including those that target natriuretic peptides and myosin activators. A large number of completely novel targets are also emerging from laboratory-based research. Better understanding of pathophysiological mechanisms driving heart failure in different settings (e.g. hypertension, post-myocardial infarction, metabolic dysfunction) may allow for targeted therapies. Areas timely for developing research Therapeutic targets directed towards modifying the extracellular environment, angiogenesis, cell viability, contractile function and microRNA-based therapies. PMID:27365454
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Target organ damage in primary hypertensive patients: role of the morning heart rate surge.
Zhan, Yuliang; Kang, Ting; Wei, Yunfeng
The morning heart rate surge (MHRS) and morning blood pressure surge (MBPS) may be responsible for the high prevalence of cardiovascular events during the morning period. The clinical significance of the MBPS has been well established, but that of the MHRS remains unclear. Thus, we evaluated the association between the MHRS and target organ damage (TOD). A cross-sectional study of 580 hypertensive patients was performed. MHRS and heart rate variability (HRV) were analyzed by 24 h electrocardiogram. TOD was assessed by estimated glomerular filtration rate, carotid intima-media thickness (IMT), and left ventricular mass index. The prevalence of TOD tended to decrease with sleep-trough MHRS (first to fourth quartiles: 71%, 70.3%, 58.6%, and 52.7%, respectively) or prewaking MHRS quartiles (first to fourth quartiles: 65.3%, 73.6%, 61.4%, and 54.2%, respectively), whereas the opposite trend was observed for standard deviation of all normal NN intervals (SDNN). Moreover, sleep-trough MHRS, prewaking MHRS, SDNN, and SDNN index were significantly lower in patients with TOD than in those without TOD. According to four logistic regression models, the associations of prewaking MHRS, SDNN, and SDNN index with TOD were lost after adjustment for age and BP. Patients in the first (≤11.125 bpm) and second sleep-trough MHRS quartiles (11.125-15.75 bpm) had a 1.95-2.06-fold increased risk of TOD compared with those in the fourth quartile (p < 0.05). A blunted sleep-trough MHRS, which may serve as a surrogate marker for autonomic imbalance, was independently associated with TOD in primary hypertensive patients.
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Association between heart rate variability and manual pulse rate.
Hart, John
2013-09-01
One model for neurological assessment in chiropractic pertains to autonomic variability, tested commonly with heart rate variability (HRV). Since HRV may not be convenient to use on all patient visits, more user-friendly methods may help fill-in the gaps. Accordingly, this study tests the association between manual pulse rate and heart rate variability. The manual rates were also compared to the heart rate derived from HRV. Forty-eight chiropractic students were examined with heart rate variability (SDNN and mean heart rate) and two manual radial pulse rate measurements. Inclusion criteria consisted of participants being chiropractic students. Exclusion criteria for 46 of the participants consisted of a body mass index being greater than 30, age greater than 35, and history of: a) dizziness upon standing, b) treatment of psychiatric disorders, and c) diabetes. No exclusion criteria were applied to the remaining two participants who were also convenience sample volunteers. Linear associations between the manual pulse rate methods and the two heart rate variability measures (SDNN and mean heart) were tested with Pearson's correlation and simple linear regression. Moderate strength inverse (expected) correlations were observed between both manual pulse rate methods and SDNN (r = -0.640, 95% CI -0.781, -0.435; r = -0.632, 95% CI -0.776, -0.425). Strong direct (expected) relationships were observed between the manual pulse rate methods and heart rate derived from HRV technology (r = 0.934, 95% CI 0.885, 0.962; r = 0.941, 95% CI 0.897, 0.966). Manual pulse rates may be a useful option for assessing autonomic variability. Furthermore, this study showed a strong relationship between manual pulse rates and heart rate derived from HRV technology.
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... Venous Thromboembolism Aortic Aneurysm More Blood Pressure vs. Heart Rate (Pulse) Updated:Nov 13,2017 Understanding the difference ... your blood moving through your blood vessels, your heart rate is the number of times your heart beats ...
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NASA Technical Reports Server (NTRS)
1984-01-01
In the mid 70's, NASA saw a need for a long term electrocardiographic electrode suitable for use on astronauts. Heart Rate Inc.'s insulated capacitive electrode is constructed of thin dielectric film applied to stainless steel surface, originally developed under a grant by Texas Technical University. HRI, Inc. was awarded NASA license and continued development of heart rate monitor for use on exercise machines for physical fitness and medical markets.
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... sinoatrial (SA) node --- the heart's natural pacemaker. A series of early beats in the atria speeds up the heart rate. The rapid heartbeat does not allow enough time for the heart to fill before it contracts ...
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Lessons from the Heart: Individualizing Physical Education with Heart Rate Monitors.
ERIC Educational Resources Information Center
Kirkpatrick, Beth; Birnbaum, Burton H.
Learning about the relationship between heart rate and physical activity is an important aspect of fitness education. Use of a heart rate monitor (HRM) helps a student to understand how stretching and large muscle movements gradually increase the heart rate and blood flow, and enables students to measure their exercise heart rates and set goals…
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ERIC Educational Resources Information Center
Laurson, Kelly R.; Brown, Dale D.; Cullen, Robert W.; Dennis, Karen K.
2008-01-01
This study examined how activity type influenced heart rates and time spent in target heart rate zones of high school students participating in physical education classes. Significantly higher average heart rates existed for fitness (142 plus or minus 24 beats per minute [bpm]) compared to team (118 plus or minus 24 bpm) or individual (114 plus or…
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Heart rate changes during electroconvulsive therapy
2013-01-01
Background This observational study documented heart rate over the entire course of electrically induced seizures and aimed to evaluate the effects of stimulus electrode placement, patients' age, stimulus dose, and additional predictors. Method In 119 consecutive patients with 64 right unilateral (RUL) and 55 bifrontal (BF) electroconvulsive treatments, heart rate graphs based on beat-to-beat measurements were plotted up to durations of 130 s. Results In RUL stimulation, the initial drop in heart rate lasted for 12.5 ± 2.6 s (mean ± standard deviation). This depended on stimulus train duration, age, and baseline heart rate. In seizures induced with BF electrode placement, a sympathetic response was observed within the first few seconds of the stimulation phase (median 3.5 s). This was also the case with subconvulsive stimulations. The mean peak heart rate in all 119 treatments amounted to 135 ± 20 bpm and depended on baseline heart rate and seizure duration; electrode placement, charge dose, and age were insignificant in regression analysis. A marked decline in heart rate in connection with seizure cessation occurred in 71% of treatments. Conclusions A significant independent effect of stimulus electrode positioning on cardiac action was evident only in the initial phase of the seizures. Electrical stimulation rather than the seizure causes the initial heart rate increase in BF treatments. The data reveal no rationale for setting the stimulus doses as a function of intraictal peak heart rates (‘benchmark method’). The marked decline in heart rate at the end of most seizures is probably mediated by a baroreceptor reflex. PMID:23764036
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Influence of ECG sampling rate in fetal heart rate variability analysis.
De Jonckheere, J; Garabedian, C; Charlier, P; Champion, C; Servan-Schreiber, E; Storme, L; Debarge, V; Jeanne, M; Logier, R
2017-07-01
Fetal hypoxia results in a fetal blood acidosis (pH<;7.10). In such a situation, the fetus develops several adaptation mechanisms regulated by the autonomic nervous system. Many studies demonstrated significant changes in heart rate variability in hypoxic fetuses. So, fetal heart rate variability analysis could be of precious help for fetal hypoxia prediction. Commonly used fetal heart rate variability analysis methods have been shown to be sensitive to the ECG signal sampling rate. Indeed, a low sampling rate could induce variability in the heart beat detection which will alter the heart rate variability estimation. In this paper, we introduce an original fetal heart rate variability analysis method. We hypothesize that this method will be less sensitive to ECG sampling frequency changes than common heart rate variability analysis methods. We then compared the results of this new heart rate variability analysis method with two different sampling frequencies (250-1000 Hz).
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Heart Rate Assessment Immediately after Birth.
Phillipos, Emily; Solevåg, Anne Lee; Pichler, Gerhard; Aziz, Khalid; van Os, Sylvia; O'Reilly, Megan; Cheung, Po-Yin; Schmölzer, Georg M
2016-01-01
Heart rate assessment immediately after birth in newborn infants is critical to the correct guidance of resuscitation efforts. There are disagreements as to the best method to measure heart rate. The aim of this study was to assess different methods of heart rate assessment in newborn infants at birth to determine the fastest and most accurate method. PubMed, EMBASE and Google Scholar were systematically searched using the following terms: 'infant', 'heart rate', 'monitoring', 'delivery room', 'resuscitation', 'stethoscope', 'auscultation', 'palpation', 'pulse oximetry', 'electrocardiogram', 'Doppler ultrasound', 'photoplethysmography' and 'wearable sensors'. Eighteen studies were identified that described various methods of heart rate assessment in newborn infants immediately after birth. Studies examining auscultation, palpation, pulse oximetry, electrocardiography and Doppler ultrasound as ways to measure heart rate were included. Heart rate measurements by pulse oximetry are superior to auscultation and palpation, but there is contradictory evidence about its accuracy depending on whether the sensor is connected to the infant or the oximeter first. Several studies indicate that electrocardiogram provides a reliable heart rate faster than pulse oximetry. Doppler ultrasound shows potential for clinical use, however future evidence is needed to support this conclusion. Heart rate assessment is important and there are many measurement methods. The accuracy of routinely applied methods varies, with palpation and auscultation being the least accurate and electrocardiogram being the most accurate. More research is needed on Doppler ultrasound before its clinical use. © 2015 S. Karger AG, Basel.
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den Hoed, Marcel; Eijgelsheim, Mark; Esko, Tõnu; Brundel, Bianca J J M; Peal, David S; Evans, David M; Nolte, Ilja M; Segrè, Ayellet V; Holm, Hilma; Handsaker, Robert E; Westra, Harm-Jan; Johnson, Toby; Isaacs, Aaron; Yang, Jian; Lundby, Alicia; Zhao, Jing Hua; Kim, Young Jin; Go, Min Jin; Almgren, Peter; Bochud, Murielle; Boucher, Gabrielle; Cornelis, Marilyn C; Gudbjartsson, Daniel; Hadley, David; van der Harst, Pim; Hayward, Caroline; den Heijer, Martin; Igl, Wilmar; Jackson, Anne U; Kutalik, Zoltán; Luan, Jian'an; Kemp, John P; Kristiansson, Kati; Ladenvall, Claes; Lorentzon, Mattias; Montasser, May E; Njajou, Omer T; O'Reilly, Paul F; Padmanabhan, Sandosh; St Pourcain, Beate; Rankinen, Tuomo; Salo, Perttu; Tanaka, Toshiko; Timpson, Nicholas J; Vitart, Veronique; Waite, Lindsay; Wheeler, William; Zhang, Weihua; Draisma, Harmen H M; Feitosa, Mary F; Kerr, Kathleen F; Lind, Penelope A; Mihailov, Evelin; Onland-Moret, N Charlotte; Song, Ci; Weedon, Michael N; Xie, Weijia; Yengo, Loic; Absher, Devin; Albert, Christine M; Alonso, Alvaro; Arking, Dan E; de Bakker, Paul I W; Balkau, Beverley; Barlassina, Cristina; Benaglio, Paola; Bis, Joshua C; Bouatia-Naji, Nabila; Brage, Søren; Chanock, Stephen J; Chines, Peter S; Chung, Mina; Darbar, Dawood; Dina, Christian; Dörr, Marcus; Elliott, Paul; Felix, Stephan B; Fischer, Krista; Fuchsberger, Christian; de Geus, Eco J C; Goyette, Philippe; Gudnason, Vilmundur; Harris, Tamara B; Hartikainen, Anna-Liisa; Havulinna, Aki S; Heckbert, Susan R; Hicks, Andrew A; Hofman, Albert; Holewijn, Suzanne; Hoogstra-Berends, Femke; Hottenga, Jouke-Jan; Jensen, Majken K; Johansson, Asa; Junttila, Juhani; Kääb, Stefan; Kanon, Bart; Ketkar, Shamika; Khaw, Kay-Tee; Knowles, Joshua W; Kooner, Angrad S; Kors, Jan A; Kumari, Meena; Milani, Lili; Laiho, Päivi; Lakatta, Edward G; Langenberg, Claudia; Leusink, Maarten; Liu, Yongmei; Luben, Robert N; Lunetta, Kathryn L; Lynch, Stacey N; Markus, Marcello R P; Marques-Vidal, Pedro; Mateo Leach, Irene; McArdle, Wendy L; McCarroll, Steven A; Medland, Sarah E; Miller, Kathryn A; Montgomery, Grant W; Morrison, Alanna C; Müller-Nurasyid, Martina; Navarro, Pau; Nelis, Mari; O'Connell, Jeffrey R; O'Donnell, Christopher J; Ong, Ken K; Newman, Anne B; Peters, Annette; Polasek, Ozren; Pouta, Anneli; Pramstaller, Peter P; Psaty, Bruce M; Rao, Dabeeru C; Ring, Susan M; Rossin, Elizabeth J; Rudan, Diana; Sanna, Serena; Scott, Robert A; Sehmi, Jaban S; Sharp, Stephen; Shin, Jordan T; Singleton, Andrew B; Smith, Albert V; Soranzo, Nicole; Spector, Tim D; Stewart, Chip; Stringham, Heather M; Tarasov, Kirill V; Uitterlinden, André G; Vandenput, Liesbeth; Hwang, Shih-Jen; Whitfield, John B; Wijmenga, Cisca; Wild, Sarah H; Willemsen, Gonneke; Wilson, James F; Witteman, Jacqueline C M; Wong, Andrew; Wong, Quenna; Jamshidi, Yalda; Zitting, Paavo; Boer, Jolanda M A; Boomsma, Dorret I; Borecki, Ingrid B; van Duijn, Cornelia M; Ekelund, Ulf; Forouhi, Nita G; Froguel, Philippe; Hingorani, Aroon; Ingelsson, Erik; Kivimaki, Mika; Kronmal, Richard A; Kuh, Diana; Lind, Lars; Martin, Nicholas G; Oostra, Ben A; Pedersen, Nancy L; Quertermous, Thomas; Rotter, Jerome I; van der Schouw, Yvonne T; Verschuren, W M Monique; Walker, Mark; Albanes, Demetrius; Arnar, David O; Assimes, Themistocles L; Bandinelli, Stefania; Boehnke, Michael; de Boer, Rudolf A; Bouchard, Claude; Caulfield, W L Mark; Chambers, John C; Curhan, Gary; Cusi, Daniele; Eriksson, Johan; Ferrucci, Luigi; van Gilst, Wiek H; Glorioso, Nicola; de Graaf, Jacqueline; Groop, Leif; Gyllensten, Ulf; Hsueh, Wen-Chi; Hu, Frank B; Huikuri, Heikki V; Hunter, David J; Iribarren, Carlos; Isomaa, Bo; Jarvelin, Marjo-Riitta; Jula, Antti; Kähönen, Mika; Kiemeney, Lambertus A; van der Klauw, Melanie M; Kooner, Jaspal S; Kraft, Peter; Iacoviello, Licia; Lehtimäki, Terho; Lokki, Marja-Liisa L; Mitchell, Braxton D; Navis, Gerjan; Nieminen, Markku S; Ohlsson, Claes; Poulter, Neil R; Qi, Lu; Raitakari, Olli T; Rimm, Eric B; Rioux, John D; Rizzi, Federica; Rudan, Igor; Salomaa, Veikko; Sever, Peter S; Shields, Denis C; Shuldiner, Alan R; Sinisalo, Juha; Stanton, Alice V; Stolk, Ronald P; Strachan, David P; Tardif, Jean-Claude; Thorsteinsdottir, Unnur; Tuomilehto, Jaako; van Veldhuisen, Dirk J; Virtamo, Jarmo; Viikari, Jorma; Vollenweider, Peter; Waeber, Gérard; Widen, Elisabeth; Cho, Yoon Shin; Olsen, Jesper V; Visscher, Peter M; Willer, Cristen; Franke, Lude; Erdmann, Jeanette; Thompson, John R; Pfeufer, Arne; Sotoodehnia, Nona; Newton-Cheh, Christopher; Ellinor, Patrick T; Stricker, Bruno H Ch; Metspalu, Andres; Perola, Markus; Beckmann, Jacques S; Smith, George Davey; Stefansson, Kari; Wareham, Nicholas J; Munroe, Patricia B; Sibon, Ody C M; Milan, David J; Snieder, Harold; Samani, Nilesh J; Loos, Ruth J F
2013-06-01
Elevated resting heart rate is associated with greater risk of cardiovascular disease and mortality. In a 2-stage meta-analysis of genome-wide association studies in up to 181,171 individuals, we identified 14 new loci associated with heart rate and confirmed associations with all 7 previously established loci. Experimental downregulation of gene expression in Drosophila melanogaster and Danio rerio identified 20 genes at 11 loci that are relevant for heart rate regulation and highlight a role for genes involved in signal transmission, embryonic cardiac development and the pathophysiology of dilated cardiomyopathy, congenital heart failure and/or sudden cardiac death. In addition, genetic susceptibility to increased heart rate is associated with altered cardiac conduction and reduced risk of sick sinus syndrome, and both heart rate-increasing and heart rate-decreasing variants associate with risk of atrial fibrillation. Our findings provide fresh insights into the mechanisms regulating heart rate and identify new therapeutic targets.
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Targeting G protein-coupled receptor kinases (GRKs) in Heart Failure
Brinks, Henriette; Koch, Walter J
2010-01-01
In the human body, over 1000 different G protein-coupled receptors (GPCRs) mediate a broad spectrum of extracellular signals at the plasma membrane, transmitting vital physiological features such as pain, sight, smell, inflammation, heart rate and contractility of muscle cells. Signaling through these receptors is primarily controlled and regulated by a group of kinases, the GPCR kinases (GRKs), of which only seven are known and thus, interference with these common downstream GPCR regulators suggests a powerful therapeutic strategy. Molecular modulation of the kinases that are ubiquitously expressed in the heart has proven GRK2, and also GRK5, to be promising targets for prevention and reversal of one of the most severe pathologies in man, chronic heart failure (HF). In this article we will focus on the structural aspects of these GRKs important for their physiological and pathological regulation as well as well known and novel therapeutic approaches that target these GRKs in order to overcome the development of cardiac injury and progression of HF. PMID:21218155
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NASA Technical Reports Server (NTRS)
Zahorian, Stephen A. (Inventor); Livingston, David L. (Inventor); Pretlow, III, Robert A. (Inventor)
1996-01-01
An apparatus for acquiring signals emitted by a fetus, identifying fetal heart beats and determining a fetal heart rate. Multiple sensor signals are outputted by a passive fetal heart rate monitoring sensor. Multiple parallel nonlinear filters filter these multiple sensor signals to identify fetal heart beats in the signal data. A processor determines a fetal heart rate based on these identified fetal heart beats. The processor includes the use of a figure of merit weighting of heart rate estimates based on the identified heart beats from each filter for each signal. The fetal heart rate thus determined is outputted to a display, storage, or communications channel. A method for enhanced fetal heart beat discrimination includes acquiring signals from a fetus, identifying fetal heart beats from the signals by multiple parallel nonlinear filtering, and determining a fetal heart rate based on the identified fetal heart beats. A figure of merit operation in this method provides for weighting a plurality of fetal heart rate estimates based on the identified fetal heart beats and selecting the highest ranking fetal heart rate estimate.
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NASA Technical Reports Server (NTRS)
Zahorian, Stephen A. (Inventor); Livingston, David L. (Inventor); Pretlow, Robert A., III (Inventor)
1994-01-01
An apparatus for acquiring signals emitted by a fetus, identifying fetal heart beats and determining a fetal heart rate is presented. Multiple sensor signals are outputted by a passive fetal heart rate monitoring sensor. Multiple parallel nonlinear filters filter these multiple sensor signals to identify fetal heart beats in the signal data. A processor determines a fetal heart rate based on these identified fetal heart beats. The processor includes the use of a figure of merit weighting of heart rate estimates based on the identified heart beats from each filter for each signal. The fetal heart rate thus determined is outputted to a display, storage, or communications channel. A method for enhanced fetal heart beat discrimination includes acquiring signals from a fetus, identifying fetal heart beats from the signals by multiple parallel nonlinear filtering, and determining a fetal heart rate based on the identified fetal heart beats. A figure of merit operation in this method provides for weighting a plurality of fetal heart rate estimates based on the identified fetal heart beats and selecting the highest ranking fetal heart rate estimate.
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Heart rate reduction and longevity in mice.
Gent, Sabine; Kleinbongard, Petra; Dammann, Philip; Neuhäuser, Markus; Heusch, Gerd
2015-03-01
Heart rate correlates inversely with life span across all species, including humans. In patients with cardiovascular disease, higher heart rate is associated with increased mortality, and such patients benefit from pharmacological heart rate reduction. However, cause-and-effect relationships between heart rate and longevity, notably in healthy individuals, are not established. We therefore prospectively studied the effects of a life-long pharmacological heart rate reduction on longevity in mice. We hypothesized, that the total number of cardiac cycles is constant, and that a 15% heart rate reduction might translate into a 15% increase in life span. C57BL6/J mice received either placebo or ivabradine at a dose of 50 mg/kg/day in drinking water from 12 weeks to death. Heart rate and body weight were monitored. Autopsy was performed on all non-autolytic cadavers, and parenchymal organs were evaluated macroscopically. Ivabradine reduced heart rate by 14% (median, interquartile range 12-15%) throughout life, and median life span was increased by 6.2% (p = 0.01). Body weight and macroscopic findings were not different between placebo and ivabradine. Life span was not increased to the same extent as heart rate was reduced, but nevertheless significantly prolonged by 6.2%.
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The effects of heart rate control in chronic heart failure with reduced ejection fraction.
Grande, Dario; Iacoviello, Massimo; Aspromonte, Nadia
2018-07-01
Elevated heart rate has been associated with worse prognosis both in the general population and in patients with heart failure. Heart rate is finely modulated by neurohormonal signals and it reflects the balance between the sympathetic and the parasympathetic limbs of the autonomic nervous system. For this reason, elevated heart rate in heart failure has been considered an epiphenomenon of the sympathetic hyperactivation during heart failure. However, experimental and clinical evidence suggests that high heart rate could have a direct pathogenetic role. Consequently, heart rate might act as a pathophysiological mediator of heart failure as well as a marker of adverse outcome. This hypothesis has been supported by the observation that the positive effect of beta-blockade could be linked to the degree of heart rate reduction. In addition, the selective heart rate control with ivabradine has recently been demonstrated to be beneficial in patients with heart failure and left ventricular systolic dysfunction. The objective of this review is to examine the pathophysiological implications of elevated heart rate in chronic heart failure and explore the mechanisms underlying the effects of pharmacological heart rate control.
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Rhesus monkey heart rate during exercise
NASA Technical Reports Server (NTRS)
Delorge, J.; Thach, J. S., Jr.
1972-01-01
Various schedules of reinforcement and their relation to heart rates of rhesus monkeys during exercise are described. All the reinforcement schedules produced 100 per cent or higher increments in the heart rates of the monkeys during exercise. Resting heart rates were generally much lower than those previously reported, which was attributed to the lack of physical restraint of the monkeys during recording.
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FIT Kids: Time in target heart zone and cognitive performance.
Castelli, Darla M; Hillman, Charles H; Hirsch, Jennifer; Hirsch, Alayna; Drollette, Eric
2011-06-01
This present study examined time spent in the target heart zone (THZ) and its relationship to tasks requiring variable amounts of executive control function in prepubescent children participating in a 9-month randomized controlled physical activity program. A sample of 59 participants performed the Stroop Color-Word Test and the Comprehensive Trail Making Test cognitive assessments. Heart rate data were collected during participation in the physical activity program using E600 heart rate monitors (Polar, Finland). There was a significant difference, F(1, 58)=7.44, p <.009, between males and females for relative VO2max, but not absolute (p=.69) or percent VO2max (p=.73). Regression analysis identified KBIT, age, and mean time above the THZ as significant predictors of performance in the Stroop Color-Word condition, F(1, 56)=5.21, p=.02. KBIT and mean time above the THZ were significant predictors for Trails B, F(1, 56)=7.60. These results suggest that heart rate, as a measure of physical activity intensity, should be closely monitored during research that is intended to make inferences about its effects on cognitive performance as participation in vigorous activities may have specific benefits over lower intensities among prepubescent children. Copyright © 2011. Published by Elsevier Inc.
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Fetal heart rate and fetal heart rate variability in Lipizzaner broodmares.
Baska-Vincze, Boglárka; Baska, Ferenc; Szenci, Ottó
2015-03-01
Monitoring fetal heart rate (FHR) and fetal heart rate variability (FHRV) helps to understand and evaluate normal and pathological conditions in the foal. The aim of this study was to establish normal heart rate reference values for the ongoing equine pregnancy and to perform a heart rate variability (HRV) time-domain analysis in Lipizzaner mares. Seventeen middle- and late-term (days 121-333) pregnant Lipizzaner mares were examined using fetomaternal electrocardiography (ECG). The mean FHR (P = 0.004) and the standard deviation of FHR (P = 0.012) significantly decreased during the pregnancy. FHR ± SD values decreased from 115 ± 35 to 79 ± 9 bpm between months 5 and 11. Our data showed that HRV in the foal decreased as the pregnancy progressed, which is in contrast with the findings of earlier equine studies. The standard deviation of normal-normal intervals (SDNN) was higher (70 ± 25 to 166 ± 108 msec) than described previously. The root mean square of successive differences (RMSSD) decreased from 105 ± 69 to 77 ± 37 msec between the 5th and 11th month of gestation. Using telemetric ECG equipment, we could detect equine fetal heartbeat on day 121 for the first time. In addition, the large differences observed in the HR values of four mare-fetus pairs in four consecutive months support the assumption that there might be 'high-HR' and 'low-HR' fetuses in horses. It can be concluded that the analysis of FHR and FHRV is a promising tool for the assessment of fetal well-being but the applicability of these parameters in the clinical setting and in studs requires further investigation.
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Heart rate variability and aerobic fitness.
De Meersman, R E
1993-03-01
Heart rate variability, a noninvasive marker of parasympathetic activity, diminishes with aging and is augmented after exercise training. Whether habitual exercise over time can attenuate this loss is unknown. This cross-sectional investigation compared 72 male runners, aged 15 to 83 to 72 age- and weight-matched sedentary control subjects for the amplitude of their heart rate variability. Heart rate variability was assessed during rest while subjects were breathing at a rate of 6 breaths per minute and at an augmented tidal volume (tidal volume = 30% of vital capacity). Fitness levels were assessed with on-line, open-circuit spirometry while subjects were performing an incremental stress test. Overall results between the two groups showed that the physically active group had significantly higher fitness levels (p < 0.001), which were associated with significantly higher levels of heart rate variability, when compared with their sedentary counterparts (p < 0.001). These findings provide suggestive evidence for habitual aerobic exercise as a beneficial modulator of heart rate variability in an aging population.
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Heart Rate Sensor for Freshwater Mussels
NASA Astrophysics Data System (ADS)
Just, C. L.; Vial, D. P.; Kruger, A.; Niemeier, J. J.; Lee, H. W.; Schroer, H. W.
2014-12-01
Researchers have long been interested the cardiac activity of mollusks. First, it is important as a basic measure of the animal's metabolism. Further, activities such as feeding and burrowing affect heart rate, as do environmental factors such as water salinity, water temperature, exposure, and predation. We have developed a small, noninvasive sensor for measuring freshwater mussel heart rate. Its working principle is as follows. An infrared (IR) light-emitting diode is placed in contact with the mussel shell. Some of the IR penetrates through the shell, reflects off internal organs, and traverses back. A photodetector detects this IR, and electronics condition the signal. The heartbeat of the animal modulates the IR, allowing one to measure the heart rate. The technique is widely-used in finger heart-rate monitors in humans. The sensors do not have to be positioned above the heart and several locations on the mussel shell work well. The sensor is small (8 mm × 10 mm) and consumes less than 1 mA, and has a simple one-wire interface that allows for easy integration into data acquisition hardware. We present heart rate measurements for the common pocketbook (lampsilis cardium) freshwater mussel.
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Catecholamine-Independent Heart Rate Increases Require CaMKII
Gao, Zhan; Singh, Madhu V; Hall, Duane D; Koval, Olha M.; Luczak, Elizabeth D.; Joiner, Mei-ling A.; Chen, Biyi; Wu, Yuejin; Chaudhary, Ashok K; Martins, James B; Hund, Thomas J; Mohler, Peter J; Song, Long-Sheng; Anderson, Mark E.
2011-01-01
Background Catecholamines increase heart rate by augmenting the cAMP responsive HCN4 ‘pacemaker current’ (If) and/or by promoting inward Na+/Ca2+ exchanger current (INCX), by a ‘Ca2+ clock’ mechanism in sinoatrial nodal cells (SANCs). The importance, identity and function of signals that connect If and Ca2+ clock mechanisms are uncertain and controversial, but the multifunctional Ca2+ and calmodulin-dependent protein kinase II (CaMKII) is required for physiological heart rate responses to β-adrenergic receptor (β-AR) stimulation. The aim of this stuy is to measure the contribution of the Ca2+ clock and CaMKII to cardiac pacing independent of β-AR agonist stimulation. Methods and Results We used the L-type Ca2+ channel agonist BayK 8644 (BayK) to activate the SANC Ca2+ clock. BayK and isoproterenol were similarly effective in increasing rates in SANCs and Langendorff-perfused hearts from WT control mice. In contrast, SANCs and isolated hearts from mice with CaMKII inhibition by transgenic expression of an inhibitory peptide (AC3-I) were resistant to rate increases by BayK. BayK only activated CaMKII in control SANCs, but increased ICa equally in all SANCs, indicating that increasing ICa was insufficient and suggesting CaMKII activation was required for heart rate increases by BayK. BayK did not increase If or protein kinase A (PKA)-dependent phosphorylation of phospholamban (at Ser16), indicating that increased SANC Ca2+ by BayK did not augment cAMP/PKA signaling at these targets. Late diastolic intracellular Ca2+ release and INCX were significantly reduced in AC3-I SANCs and the response to BayK was eliminated by ryanodine in all groups. Conclusions The Ca2+ clock is capable of supporting physiological fight or flight responses, independent of β-AR stimulation or If increases. Complete Ca2+ clock and β-AR stimulation responses require CaMKII. PMID:21406683
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Fu, M; Ahrenmark, U; Berglund, S; Lindholm, C J; Lehto, A; Broberg, A Månsson; Tasevska-Dinevska, G; Wikstrom, G; Ågard, A; Andersson, B
2017-12-01
Despite that heart rate (HR) control is one of the guideline-recommended treatment goals for heart failure (HF) patients, implementation has been painstakingly slow. Therefore, it would be important to identify patients who have not yet achieved their target heart rates and assess possible underlying reasons as to why the target rates are not met. The survey of HR in patients with HF in Sweden (HR-HF survey) is an investigator-initiated, prospective, multicenter, observational longitudinal study designed to investigate the state of the art in the control of HR in HF and to explore potential underlying mechanisms for suboptimal HR control with focus on awareness of and adherence to guidelines for HR control among physicians who focus on the contributing role of beta-blockers (BBs). In 734 HF patients the mean HR was 68 ± 12 beats per minute (bpm) (37.2% of the patients had a HR >70 bpm). Patients with HF with reduced ejection fraction (HFrEF) (n = 425) had the highest HR (70 ± 13 bpm, with 42% >70 bpm), followed by HF with preserved ejection fraction and HF with mid-range ejection fraction. Atrial fibrillation, irrespective of HF type, had higher HR than sinus rhythm. A similar pattern was observed with BB treatment. Moreover, non-achievement of the recommended target HR (<70 bpm) in HFrEF and sinus rhythm was unrelated to age, sex, cardiovascular risk factors, cardiovascular diseases, and comorbidities, but was related to EF and the clinical decision of the physician. Approximately 50% of the physicians considered a HR of >70 bpm optimal and an equal number considered a HR of >70 bpm too high, but without recommending further action. Furthermore, suboptimal HR control cannot be attributed to the use of BBs because there was neither a difference in use of BBs nor an interaction with BBs for HR >70 bpm compared with HR <70 bpm. Suboptimal control of HR was noted in HFrEF with sinus rhythm, which appeared to be attributable to physician decision
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Wadehn, Federico; Carnal, David; Loeliger, Hans-Andrea
2015-08-01
Heart rate variability is one of the key parameters for assessing the health status of a subject's cardiovascular system. This paper presents a local model fitting algorithm used for finding single heart beats in photoplethysmogram recordings. The local fit of exponentially decaying cosines of frequencies within the physiological range is used to detect the presence of a heart beat. Using 42 subjects from the CapnoBase database, the average heart rate error was 0.16 BPM and the standard deviation of the absolute estimation error was 0.24 BPM.
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Wiklund, Urban; Karlsson, Marcus; Oström, Mats; Messner, Torbjörn
2009-01-01
Media have anecdotally reported that drinking energy drinks in combination with alcohol and exercise could cause sudden cardiac death. This study investigated changes in the electrocardiogram (ECG) and heart rate variability after intake of an energy drink, taken in combination with alcohol and exercise. Ten healthy volunteers (five men and five women aged 19-30) performed maximal bicycle ergometer exercise for 30 min after: (i) intake of 0.75 l of an energy drink mixed with alcohol; (ii) intake of energy drink; and, (iii) no intake of any drink. ECG was continuously recorded for analysis of heart rate variability and heart rate recovery. No subject developed any clinically significant arrhythmias. Post-exercise recovery in heart rate and heart rate variability was slower after the subjects consumed energy drink and alcohol before exercise, than after exercise alone. The healthy subjects developed blunted cardiac autonomic modulation after exercising when they had consumed energy drinks mixed with alcohol. Although they did not develop any significant arrhythmia, individuals predisposed to arrhythmia by congenital or other rhythm disorders could have an increased risk for malignant cardiac arrhythmia in similar situations.
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Gąsior, Jakub S.; Sacha, Jerzy; Jeleń, Piotr J.; Zieliński, Jakub; Przybylski, Jacek
2016-01-01
Background: Since heart rate variability (HRV) is associated with average heart rate (HR) and respiratory rate (RespRate), alterations in these parameters may impose changes in HRV. Hence the repeatability of HRV measurements may be affected by differences in HR and RespRate. The study aimed to evaluate HRV repeatability and its association with changes in HR and RespRate. Methods: Forty healthy volunteers underwent two ECG examinations 7 days apart. Standard HRV indices were calculated from 5-min ECG recordings. The ECG-derived respiration signal was estimated to assess RespRate. To investigate HR impact on HRV, HRV parameters were corrected for prevailing HR. Results: Differences in HRV parameters between the measurements were associated with the changes in HR and RespRate. However, in multiple regression analysis only HR alteration proved to be independent determinant of the HRV differences—every change in HR by 1 bpm changed HRV values by 16.5% on average. After overall removal of HR impact on HRV, coefficients of variation of the HRV parameters significantly dropped on average by 26.8% (p < 0.001), i.e., by the same extent HRV reproducibility improved. Additionally, the HRV correction for HR decreased association between RespRate and HRV. Conclusions: In stable conditions, HR but not RespRate is the most powerful factor determining HRV reproducibility and even a minimal change of HR may considerably alter HRV. However, the removal of HR impact may significantly improve HRV repeatability. The association between HRV and RespRate seems to be, at least in part, HR dependent. PMID:27588006
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Accuracy of smartphone apps for heart rate measurement.
Coppetti, Thomas; Brauchlin, Andreas; Müggler, Simon; Attinger-Toller, Adrian; Templin, Christian; Schönrath, Felix; Hellermann, Jens; Lüscher, Thomas F; Biaggi, Patric; Wyss, Christophe A
2017-08-01
Background Smartphone manufacturers offer mobile health monitoring technology to their customers, including apps using the built-in camera for heart rate assessment. This study aimed to test the diagnostic accuracy of such heart rate measuring apps in clinical practice. Methods The feasibility and accuracy of measuring heart rate was tested on four commercially available apps using both iPhone 4 and iPhone 5. 'Instant Heart Rate' (IHR) and 'Heart Fitness' (HF) work with contact photoplethysmography (contact of fingertip to built-in camera), while 'Whats My Heart Rate' (WMH) and 'Cardiio Version' (CAR) work with non-contact photoplethysmography. The measurements were compared to electrocardiogram and pulse oximetry-derived heart rate. Results Heart rate measurement using app-based photoplethysmography was performed on 108 randomly selected patients. The electrocardiogram-derived heart rate correlated well with pulse oximetry ( r = 0.92), IHR ( r = 0.83) and HF ( r = 0.96), but somewhat less with WMH ( r = 0.62) and CAR ( r = 0.60). The accuracy of app-measured heart rate as compared to electrocardiogram, reported as mean absolute error (in bpm ± standard error) was 2 ± 0.35 (pulse oximetry), 4.5 ± 1.1 (IHR), 2 ± 0.5 (HF), 7.1 ± 1.4 (WMH) and 8.1 ± 1.4 (CAR). Conclusions We found substantial performance differences between the four studied heart rate measuring apps. The two contact photoplethysmography-based apps had higher feasibility and better accuracy for heart rate measurement than the two non-contact photoplethysmography-based apps.
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FPGA Implementation of Heart Rate Monitoring System.
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.
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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.
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Heart rate profile during exercise in patients with early repolarization.
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 < 0.05). The lower heart rate increment (< 106 beats/min) and heart rate decrement (< 95 beats/min) were significantly associated with the presence of early repolarization. After adjustment for age and sex, the multiple-adjusted OR of the risk of presence of early repolarization was 2.98 (95%CI 1.21-7.34) (P = 0.018) and 7.73 (95%CI 2.84-21.03) (P < 0.001) for the lower heart rate increment and heart rate decrement compared to higher levels, respectively. Subjects with early repolarization have altered heart rate profile during exercise compared to control subjects. This can be related to sudden death.
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Long‐term Cardiovascular Risks Associated With an Elevated Heart Rate: The Framingham Heart Study
Ho, Jennifer E.; Larson, Martin G.; Ghorbani, Anahita; Cheng, Susan; Coglianese, Erin E.; Vasan, Ramachandran S.; Wang, Thomas J.
2014-01-01
Background Higher heart rate has been associated with an adverse prognosis, but most prior studies focused on individuals with known cardiovascular disease or examined a limited number of outcomes. We sought to examine the association of baseline heart rate with both fatal and nonfatal outcomes during 2 decades of follow‐up. Methods and Results Our study included 4058 Framingham Heart Study participants (mean age 55 years, 56% women). Cox models were performed with multivariable adjustment for clinical risk factors and physical activity. A total of 708 participants developed incident cardiovascular disease (303 heart failure, 343 coronary heart disease, and 216 stroke events), 48 received a permanent pacemaker, and 1186 died. Baseline heart rate was associated with incident cardiovascular disease (hazard ratio [HR] 1.15 per 1 SD [11 bpm] increase in heart rate, 95% CI 1.07 to 1.24, P=0.0002), particularly heart failure (HR 1.32, 95% CI 1.18 to 1.48, P<0.0001). Higher heart rate was also associated with higher all‐cause (HR 1.17, 95% CI 1.11 to 1.24, P<0.0001) and cardiovascular mortality (HR 1.18, 95% CI 1.04 to 1.33, P=0.01). Spline analyses did not suggest a lower threshold beyond which the benefit of a lower heart rate abated or increased. In contrast, individuals with a higher heart rate had a lower risk of requiring permanent pacemaker placement (HR 0.55, 95% CI 0.38 to 0.79, P=0.001). Conclusions Individuals with a higher heart rate are at elevated long‐term risk for cardiovascular events, in particular, heart failure, and all‐cause death. On the other hand, a higher heart rate is associated with a lower risk of future permanent pacemaker implantation. PMID:24811610
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A protocol to study ex vivo mouse working heart at human-like heart rate.
Feng, Han-Zhong; Jin, Jian-Ping
2018-01-01
Genetically modified mice are widely used as experimental models to study human heart function and diseases. However, the fast rate of normal mouse heart at 400-600bpm limits its capacity of assessing kinetic parameters that are important for the physiology and pathophysiology of human heart that beats at a much slower rate (75-180bpm). To extend the value of mouse models, we established a protocol to study ex vivo mouse working hearts at a human-like heart rate. In the presence of 300μM lidocaine to lower pacemaker and conductive activities and prevent arrhythmia, a stable rate of 120-130bpm at 37°C is achieved for ex vivo mouse working hearts. The negative effects of decreased heart rate on force-frequency dependence and lidocaine as a myocardial depressant on intracellular calcium can be compensated by using a higher but still physiological level of calcium (2.75mM) in the perfusion media. Multiple parameters were studied to compare the function at the human-like heart rate with that of ex vivo mouse working hearts at the standard rate of 480bpm. The results showed that the conditions for slower heart rate in the presence of 300μM lidocaine did not have depressing effect on left ventricular pressure development, systolic and diastolic velocities and stroke volume with maintained positive inotropic and lusitropic responses to β-adrenergic stimulation. Compared with that at 480bpm, the human-like heart rate increased ventricular filling and end diastolic volume with enhanced Frank-Starling responses. Coronary perfusion was increased from longer relaxation time and interval between beats whereas cardiac efficiency was significantly improved. Although the intrinsic differences between mouse and human heart remain, this methodology for ex vivo mouse hearts to work at human-like heart rate extends the value of using genetically modified mouse models to study cardiac function and human heart diseases. Copyright © 2017 Elsevier Ltd. All rights reserved.
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Kassamali, Rahil H; Kim, Daniel H; Patel, Hiten; Raichura, Nitin; Hoey, Edward T D; Hodson, James; Hussain, Shahid
2014-10-01
The purpose of this study was to assess the safety of heart rate optimization by use of β-adrenergic blockade solely by the i.v. route before coronary CT angiography. The records of 679 patients undergoing CT coronary angiography after receiving i.v. β-adrenergic blockade were retrospectively analyzed. Health screening was completed before scanning, and heart rate was optimized by administration of i.v. metoprolol titrated to a maximum of 70 mg to achieve a heart rate less than 65 beats/min. The median i.v. dose was 20 mg (range, 5-70 mg). The 679 patients analyzed had a total of 10 complications (1.47%). Major complications, defined as not resolving with observation and analgesia alone, occurred in only three patients (0.44%). These complications included a second-degree atrioventricular block. A total of 299 patients (44.0%) needed more than 20 mg of i.v. metoprolol to achieve target heart rate. Only three patients needed the maximum i.v. dose of 70 mg metoprolol. Target heart rate was reached successfully in 666 patients (98.1%) with doses of less than 70 mg. This study did not show a statistically significant association between increasing complication frequency and increasing dose. This study showed that high doses of i.v. metoprolol can be used effectively and with a low rate of major complications to control heart rate before coronary CT angiography in correctly screened patients.
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Nageotte, Michael P
2015-06-01
Electronic fetal heart rate monitoring is a widely utilized means of assessment of fetal status during labor. Whereas little evidence exists regarding efficacy, this modality continues to be used extensively in every modern labor and delivery unit in developed countries. It is of importance that all providers of health care to the woman in labor and her newborn have a clear understanding of the basic pathophysiology of fetal heart rate monitoring and an appreciation for labor course and concerns as they arise in order to optimize outcomes and patient safety. Copyright © 2015 Elsevier Ltd. All rights reserved.
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Heart-Rate Recovery After Warm-up in Swimming: A Useful Predictor of Training Heart-Rate Response?
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 < .001, R 2 = .67, SEE = 2.78). HRR after a standardized 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.
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Heart Rates of Elite Synchronized Swimmers.
ERIC Educational Resources Information Center
Gemma, Karen Erickson; Wells, Christine L.
1987-01-01
Heart rates were recorded by radiotelemetry in ten elite and national-class synchronized swimmers as they performed competitive figures of high degrees of difficulty. The focus was on changes in heart rates and electrocardiogram patterns for each body position, especially those requiring facial immersion and breath-holding. (Author/MT)
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Genome-wide association studies and resting heart rate.
Kilpeläinen, Tuomas O
Genome-wide association studies (GWASs) have revolutionized the search for genetic variants regulating resting heart rate. In the last 10years, 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 variants and genes and gain further insights into the biological mechanisms underlying the observed associations. Copyright © 2016 Elsevier Inc. All rights reserved.
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Heart rate at first postdischarge visit and outcomes in patients with heart failure.
Kim, Tae-Hun; Kim, Hyungseop; Kim, In-Cheol; Yoon, Hyuck-Jun; Park, Hyoung-Seob; Cho, Yun-Kyeong; Nam, Chang-Wook; Han, Seongwook; Hur, Seung-Ho; Kim, Yoon-Nyun
2018-07-01
Heart rate control is important to prevent adverse outcomes in patients with heart failure (HF). However, postdischarge activity may worsen heart rate control, resulting in readmission. This study aimed to explore the implications of the heart rate differences between discharge and the first outpatient visit (D-O diff). We retrospectively identified 458 patients (male: 46%; mean age: 72 years) discharged after HF. The heart rates at admission, discharge and first outpatient visit were analysed. The primary outcome was a composite of cardiovascular (CV) death and readmission of non-fatal myocardial infarction (MI), non-fatal stroke or non-fatal HF over a mean follow-up of 16 months. During follow-up, the clinical outcomes were noted in 223 patients (49%): HF, 199; stroke, 9; MI, 6; CV death, 9. The heart rate at the first outpatient visit (r=-0.311, P<0.001) and D-O diff (r=0.416, P<0.001) showed a better correlation with the time-to-clinical event than the heart rate at admission or discharge. The events group displayed a pronounced heart rate increase (13 beats/min) from discharge to the first outpatient visit compared with the event-free group (a decrease of 2 beats/min). A decrease less than -15 in the D-O diff showed a 4.5-fold risk of clinical outcomes during follow-up (P<0.001). A decreased D-O diff was related to the adverse outcomes of HF. The failure of heart rate control within more than 15 beats/min at the first outpatient visit was an independent factor for CV events. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.
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Heart Rate During Sleep: Implications for Monitoring Training Status
Waldeck, Miriam R.; Lambert, Michael I.
2003-01-01
Resting heart rate has sometimes been used as a marker of training status. It is reasonable to assume that the relationship between heart rate and training status should be more evident during sleep when extraneous factors that may influence heart rate are reduced. Therefore the aim of the study was to assess the repeatability of monitoring heart rate during sleep when training status remained unchanged, to determine if this measurement had sufficient precision to be used as a marker of training status. The heart rate of ten female subjects was monitored for 24 hours on three occasions over three weeks whilst training status remained unchanged. Average, minimum and maximum heart rate during sleep was calculated. The average heart rate of the group during sleep was similar on each of the three tests (65 ± 9, 63 ± 6 and 67 ± 7 beats·min-1 respectively). The range in minimum heart rate variation during sleep for all subjects over the three testing sessions was from 0 to 10 beats·min-1 (mean = 5 ± 3 beats·min-1) and for maximum heart rate variation was 2 to 31 beats·min-1 (mean = 13 ± 9 beats·min-1). In summary it was found that on an individual basis the minimum heart rate during sleep varied by about 8 beats·min-1. This amount of intrinsic day-to-day variation needs to be considered when changes in heart rate that may occur with changes in training status are interpreted. PMID:24688273
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Carvalho, Vitor Oliveira; Guimarães, Guilherme Veiga; Ciolac, Emmanuel Gomes; Bocchi, Edimar Alcides
2008-01-01
BACKGROUND Calculating the maximum heart rate for age is one method to characterize the maximum effort of an individual. Although this method is commonly used, little is known about heart rate dynamics in optimized beta-blocked heart failure patients. AIM The aim of this study was to evaluate heart rate dynamics (basal, peak and % heart rate increase) in optimized beta-blocked heart failure patients compared to sedentary, normal individuals (controls) during a treadmill cardiopulmonary exercise test. METHODS Twenty-five heart failure patients (49±11 years, 76% male), with an average LVEF of 30±7%, and fourteen controls were included in the study. Patients with atrial fibrillation, a pacemaker or noncardiovascular functional limitations or whose drug therapy was not optimized were excluded. Optimization was considered to be 50 mg/day or more of carvedilol, with a basal heart rate between 50 to 60 bpm that was maintained for 3 months. RESULTS Basal heart rate was lower in heart failure patients (57±3 bpm) compared to controls (89±14 bpm; p<0.0001). Similarly, the peak heart rate (% maximum predicted for age) was lower in HF patients (65.4±11.1%) compared to controls (98.6±2.2; p<0.0001). Maximum respiratory exchange ratio did not differ between the groups (1.2±0.5 for controls and 1.15±1 for heart failure patients; p=0.42). All controls reached the maximum heart rate for their age, while no patients in the heart failure group reached the maximum. Moreover, the % increase of heart rate from rest to peak exercise between heart failure (48±9%) and control (53±8%) was not different (p=0.157). CONCLUSION No patient in the heart failure group reached the maximum heart rate for their age during a treadmill cardiopulmonary exercise test, despite the fact that the percentage increase of heart rate was similar to sedentary normal subjects. A heart rate increase in optimized beta-blocked heart failure patients during cardiopulmonary exercise test over 65% of the
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Mitochondrial function as a therapeutic target in heart failure
Brown, David A.; Perry, Justin B.; Allen, Mitchell E.; Sabbah, Hani N.; Stauffer, Brian L.; Shaikh, Saame Raza; Cleland, John G. F.; Colucci, Wilson S.; Butler, Javed; Voors, Adriaan A.; Anker, Stefan D.; Pitt, Bertram; Pieske, Burkert; Filippatos, Gerasimos; Greene, Stephen J.; Gheorghiade, Mihai
2017-01-01
Heart failure is a pressing worldwide public-health problem with millions of patients having worsening heart failure. Despite all the available therapies, the condition carries a very poor prognosis. Existing therapies provide symptomatic and clinical benefit, but do not fully address molecular abnormalities that occur in cardiomyocytes. This shortcoming is particularly important given that most patients with heart failure have viable dysfunctional myocardium, in which an improvement or normalization of function might be possible. Although the pathophysiology of heart failure is complex, mitochondrial dysfunction seems to be an important target for therapy to improve cardiac function directly. Mitochondrial abnormalities include impaired mitochondrial electron transport chain activity, increased formation of reactive oxygen species, shifted metabolic substrate utilization, aberrant mitochondrial dynamics, and altered ion homeostasis. In this Consensus Statement, insights into the mechanisms of mitochondrial dysfunction in heart failure are presented, along with an overview of emerging treatments with the potential to improve the function of the failing heart by targeting mitochondria. PMID:28004807
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Validation of Heart Rate Monitor Polar RS800 for Heart Rate Variability Analysis During Exercise.
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%).
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Dissociation of heart rate variability and heart rate recovery in well-trained athletes.
Lee, C Matthew; Mendoza, Albert
2012-07-01
The purpose of this investigation was to examine the relationships between aerobic fitness, volume of physical activity (PA), heart rate variability (HRV), and heart rate recovery (HRR) in a group of well-trained endurance athletes. Nineteen endurance athletes participated in this study and had aerobic capacities that placed them above the 99th percentile based on normative values (VO(2max): 67.1 ± 2 ml kg(-1) min(-1)). HRV was obtained via an EKG collected during supine rest and reported as high-frequency (HF), low-frequency (LF), and total power (TP). Natural log (ln) transformation was applied when variables violated assumptions of normality. HRR recovery was reported as the reduction in heart rate from peak exercise to the heart rate 1 min after cessation of exercise and PA was estimated from a questionnaire. HRR was significantly correlated with PA and VO(2max) (r = 0.67, P = 0.003 and 0.51, P = 0.039, respectively), but not with any index of HRV. Age was significantly correlated with lnHF (r = -0.49, P = 0.033), lnLF/lnHF (r = 0.48, P = 0.037), and normalized units (NU) of LF (r = 0.47, P = 0.042) and HF (r = -0.47, P = 0.042). Stepwise regression revealed that the strongest predictor of HRR was PA (R (2) = 0.45) and that VO(2max) did not add significant predictive value to the model. The relationship between HRV and age is evident in well-trained endurance athletes, whereas the relationship between HRV and PA/aerobic fitness is not. The maintained relationship between HRR and PA/aerobic fitness suggests that HRR may be a better marker of fitness-related differences in autonomic control in this population.
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Heart Rate, Life Expectancy and the Cardiovascular System: Therapeutic Considerations.
Boudoulas, Konstantinos Dean; Borer, Jeffrey S; Boudoulas, Harisios
2015-01-01
It has long been known that life span is inversely related to resting heart rate in most organisms. This association between heart rate and survival has been attributed to the metabolic rate, which is greater in smaller animals and is directly associated with heart rate. Studies have shown that heart rate is related to survival in apparently healthy individuals and in patients with different underlying cardiovascular diseases. A decrease in heart rate due to therapeutic interventions may result in an increase in survival. However, there are many factors regulating heart rate, and it is quite plausible that these may independently affect life expectancy. Nonetheless, a fast heart rate itself affects the cardiovascular system in multiple ways (it increases ventricular work, myocardial oxygen consumption, endothelial stress, aortic/arterial stiffness, decreases myocardial oxygen supply, other) which, in turn, may affect survival. In this brief review, the effects of heart rate on the heart, arterial system and survival will be discussed. © 2015 S. Karger AG, Basel.
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Spot measurement of heart rate based on morphology of PhotoPlethysmoGraphic (PPG) signals.
Madhan Mohan, P; Nagarajan, V; Vignesh, J C
2017-02-01
Due to increasing health consciousness among people, it is imperative to have low-cost health care devices to measure the vital parameters like heart rate and arterial oxygen saturation (SpO 2 ). In this paper, an efficient heart rate monitoring algorithm based on the morphology of photoplethysmography (PPG) signals to measure the spot heart rate (HR) and its real-time implementation is proposed. The algorithm does pre-processing and detects the onsets and systolic peaks of the PPG signal to estimate the heart rate of the subject. Since the algorithm is based on the morphology of the signal, it works well when the subject is not moving, which is a typical test case. So, this algorithm is developed mainly to measure the heart rate at on-demand applications. Real-time experimental results indicate the heart rate accuracy of 99.5%, mean absolute percentage error (MAPE) of 1.65%, mean absolute error (MAE) of 1.18 BPM and reference closeness factor (RCF) of 0.988. The results further show that the average response time of the algorithm to give the spot HR is 6.85 s, so that the users need not wait longer to see their HR. The hardware implementation results show that the algorithm only requires 18 KBytes of total memory and runs at high speed with 0.85 MIPS. So, this algorithm can be targeted to low-cost embedded platforms.
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Vora, Rathin; Zareba, Wojciech; Utell, Mark J; Pietropaoli, Anthony P; Chalupa, David; Little, Erika L; Oakes, David; Bausch, Jan; Wiltshire, Jelani; Frampton, Mark W
2014-07-16
Diabetes may confer an increased risk for the cardiovascular health effects of particulate air pollution, but few human clinical studies of air pollution have included people with diabetes. Ultrafine particles (UFP, ≤100 nm in diameter) have been hypothesized to be an important component of particulate air pollution with regard to cardiovascular health effects. 17 never-smoker subjects 30-60 years of age, with stable type 2 diabetes but otherwise healthy, inhaled either filtered air (0-10 particles/cm3) or elemental carbon UFP (~107 particles/cm3, ~50 ug/m3, count median diameter 32 nm) by mouthpiece, for 2 hours at rest, in a double-blind, randomized, crossover study design. A digital 12-lead electrocardiogram (ECG) was recorded continuously for 48 hours, beginning 1 hour prior to exposure. Analysis of 5-minute segments of the ECG during quiet rest showed reduced high-frequency heart rate variability with UFP relative to air exposure (p = 0.014), paralleled by non-significant reductions in time-domain heart rate variability parameters. In the analysis of longer durations of the ECG, we found that UFP exposure increased the heart rate relative to air exposure. During the 21- to 45-hour interval after exposure, the average heart rate increased approximately 8 beats per minute with UFP, compared to 5 beats per minute with air (p = 0.045). There were no UFP effects on cardiac rhythm or repolarization. Inhalation of elemental carbon ultrafine particles alters heart rate and heart rate variability in people with type 2 diabetes. Our findings suggest that effects may occur and persist hours after a single 2-hour exposure.
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Jörn, H; Morgenstern, B; Wassenberg, B; Rath, W
2004-08-01
Is it useful to further analyse foetal heart rate to improve the prediction of pregnancy complications? The analysis of the foetal heart rate is usually based on the variability of the heart rate, i. e. the more variable the heart rate presents - except a decrease - the better the condition of the foetus is. The same concept is applied in our own analysis which differs only in the presentation of the data. We analysed 25 non-stress-tests from unselected third trimester pregnancies using sophisticated software. The recurrence plot (RP) is able to rearrange data from foetal heart rate monitoring in order to make the heart rate variability visible. We developed criteria for a normal and an abnormal test result describing the structure of the diagram to predict an uneventful and a high-risk pregnancy, respectively. 11 out of 11 patients with uneventful course and outcome of pregnancy showed a coarse and blurred RP pattern. 12 out of 14 (86 %) patients developing either intrauterine growth retardation or preeclampsia and requiring caesarean section because of foetal heart rate abnormalities showed a fine and clear RP pattern. Our preliminary results show that it makes sense to further evaluate foetal heart rate variability in order to predict pregnancy complications. Computer programs including the algorithms needed (calculation of the recurrence plot) are not expensive and easy to handle. A widespread use of these programs represents the basis requirement for large controlled clinical trials.
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Kaese, Sven; Bögeholz, Nils; Pauls, Paul; Dechering, Dirk; Olligs, Jan; Kölker, Katharina; Badawi, Sascha; Frommeyer, Gerrit; Pott, Christian; Eckardt, Lars
2017-08-01
The cardiac sodium/calcium (Na + /Ca 2+ ) exchanger (NCX) contributes to diastolic depolarization in cardiac pacemaker cells. Increased NCX activity has been found in heart failure and atrial fibrillation. The influence of increased NCX activity on resting heart rate, beta-adrenergic-mediated increase in heart rate, and cardiac conduction properties is unknown. The purpose of this study was to investigate the influence of NCX overexpression in a homozygous transgenic whole-heart mouse model (NCX-OE) on sinus and AV nodal function. Langendorff-perfused, beating whole hearts of NCX-OE and the corresponding wild-type (WT) were studied ± isoproterenol (ISO; 0.2 μM). Epicardial ECG, AV nodal Wenckebach cycle length (AVN-WCL), and retrograde AVN-WCL were obtained. At baseline, basal heart rate was unaltered between NCX-OE and WT (WT: cycle length [CL] 177.6 ± 40.0 ms, no. of hearts [n] = 20; NCX-OE: CL 185.9 ± 30.5 ms, n = 18; P = .21). In the presence of ISO, NCX-OE exhibited a significantly higher heart rate compared to WT (WT: CL 133.4 ± 13.4 ms, n = 20; NCX-OE: CL 117.7 ± 14.2 ms, n = 18; P <.001). ISO led to a significant shortening of the anterograde and retrograde AVN-WCL without differences between NCX-OE and WT. This study is the first to demonstrate that increased NCX activity enhances beta-adrenergic increase of heart rate. Mechanistically, increased NCX inward mode activity may promote acceleration of diastolic depolarization in sinus nodal pacemaker cells, thus enhancing chronotropy in NCX-OE. These findings suggest a novel potential therapeutic target for heart rate control in the presence of increased NCX activity, such as heart failure. Copyright © 2017 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.
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The mitochondrial uniporter controls fight or flight heart rate increases.
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.
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Arduino-based noise robust online heart-rate detection.
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.
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Targeting Cardiomyocyte Ca2+ Homeostasis in Heart Failure
Røe, Åsmund T.; Frisk, Michael; Louch, William E.
2015-01-01
Improved treatments for heart failure patients will require the development of novel therapeutic strategies that target basal disease mechanisms. Disrupted cardiomyocyte Ca2+ homeostasis is recognized as a major contributor to the heart failure phenotype, as it plays a key role in systolic and diastolic dysfunction, arrhythmogenesis, and hypertrophy and apoptosis signaling. In this review, we outline existing knowledge of the involvement of Ca2+ homeostasis in these deficits, and identify four promising targets for therapeutic intervention: the sarcoplasmic reticulum Ca2+ ATPase, the Na+-Ca2+ exchanger, the ryanodine receptor, and t-tubule structure. We discuss experimental data indicating the applicability of these targets that has led to recent and ongoing clinical trials, and suggest future therapeutic approaches. PMID:25483944
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Heart Rate and Reinforcement Sensitivity in ADHD
ERIC Educational Resources Information Center
Luman, Marjolein; Oosterlaan, Jaap; Hyde, Christopher; van Meel, Catharina S.; Sergeant, Joseph A.
2007-01-01
Background: Both theoretical and clinical accounts of attention-deficit/hyperactivity disorder (ADHD) implicate a dysfunctional reinforcement system. This study investigated heart rate parameters in response to feedback associated with reward and response cost in ADHD children and controls aged 8 to 12. Methods: Heart rate responses (HRRs)…
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How heart rate variability affects emotion regulation brain networks.
Mather, Mara; Thayer, Julian
2018-02-01
Individuals with high heart rate variability tend to have better emotional well-being than those with low heart rate variability, but the mechanisms of this association are not yet clear. In this paper, we propose the novel hypothesis that by inducing oscillatory activity in the brain, high amplitude oscillations in heart rate enhance functional connectivity in brain networks associated with emotion regulation. Recent studies using daily biofeedback sessions to increase the amplitude of heart rate oscillations suggest that high amplitude physiological oscillations have a causal impact on emotional well-being. Because blood flow timing helps determine brain network structure and function, slow oscillations in heart rate have the potential to strengthen brain network dynamics, especially in medial prefrontal regulatory regions that are particularly sensitive to physiological oscillations.
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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
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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
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Habal, Marlena V; Liu, Peter P; Austin, Peter C; Ross, Heather J; Newton, Gary E; Wang, Xuesong; Tu, Jack V; Lee, Douglas S
2014-01-01
Heart failure (HF) is associated with a high burden of morbidity and mortality. Hospital discharge is an opportunity for identification of modifiable prognostic factors in the transition to chronic HF. We examined the association of discharge heart rate with 30-day and 1-year mortality and hospitalization outcomes in a cohort of 9097 patients with HF discharged from hospital. Discharge heart rate was categorized into predefined groups: 40 to 60 (n=1333), 61 to 70 (n=2170), 71 to 80 (n=2631), 81 to 90 (n=1700), and >90 bpm (n=1263). There was a significant increase in all-cause 30-day mortality with adjusted odds ratios of 1.59 (95% confidence interval [CI], 1.18-2.14; P=0.003) for discharge heart rates 81 to 90 bpm and 1.56 (95% CI, 1.13-2.16; P=0.007) for heart rates>90 bpm when compared with the reference group (heart rates, 61-70 bpm). Cardiovascular death risk at 30 days was also higher with adjusted odds ratio 1.59 (discharge heart rates, 81-90 bpm; 95% CI, 1.09-2.33; P=0.017) and 1.65 (discharge heart rates, >90 bpm; 95% CI, 1.09-2.48; P=0.017). One-year all-cause mortality (adjusted odds ratio, 1.41; 95% CI, 1.16-1.72; P<0.001) and cardiovascular death (adjusted odds ratio, 1.47; 95% CI, 1.12-1.92; P=0.005) were higher with discharge heart rates>90 bpm when compared with the reference group (heart rates, 40-60 bpm). Readmissions for HF (adjusted hazard ratio, 1.26; 95% CI, 1.04-1.54; P=0.021) and cardiovascular disease (adjusted hazard ratio, 1.29; 95% CI, 1.08-1.54; P=0.004) within 30 days were also higher with discharge heart rates>90 bpm. Higher discharge heart rates were associated with greater risk of all-cause and cardiovascular mortality≤1-year follow-up and an elevated risk of 30-day readmission for HF and cardiovascular disease.
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Heart rate measurement based on face video sequence
NASA Astrophysics Data System (ADS)
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.
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Woo, M A; Moser, D K; Stevenson, L W; Stevenson, W G
1997-09-01
The 6-minute walk and heart rate variability have been used to assess mortality risk in patients with heart failure, but their relationship to each other and their usefulness for predicting mortality at 1 year are unknown. To assess the relationships between the 6-minute walk test, heart rate variability, and 1-year mortality. A sample of 113 patients in advanced stages of heart failure (New York Heart Association Functional Class III-IV, left ventricular ejection < 0.25) were studied. All 6-minute walks took place in an enclosed, level, measured corridor and were supervised by the same nurse. Heart rate variability was measured by using (1) a standard-deviation method and (2) Poincaré plots. Data on RR intervals obtained by using 24-hour Holter monitoring were analyzed. Survival was determined at 1 year after the Holter recording. The results showed no significant associations between the results of the 6-minute walk and the two measures of heart rate variability. The results of the walk were related to 1-year mortality but not to the risk of sudden death. Both measures of heart rate variability had significant associations with 1-year mortality and with sudden death. However, only heart rate variability measured by using Poincaré plots was a predictor of total mortality and risk of sudden death, independent of left ventricular ejection fraction, serum levels of sodium, results of the 6-minute walk test, and the standard-deviation measure of heart rate variability. Results of the 6-minute walk have poor association with mortality and the two measures of heart rate variability in patients with advanced-stage heart failure and a low ejection fraction. Further studies are needed to determine the optimal clinical usefulness of the 6-minute walk and heart rate variability in patients with advanced-stage heart failure.
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Idiosyncratic heart rate response in men during sexual arousal.
Rowland, David L; Crawford, Sara B
2011-05-01
Heart rate, sensitive to sympathetic activation, is known to change during sexual arousal and therefore may be a useful tool for investigating psychosomatic differences between sexually functional and dysfunctional men. However, heart rate during arousal also tends to be highly variable across individual men, making its predictability based on group patterns relatively poor. We wanted to determine whether individual men show idiosyncratic heart rate patterns during sexual arousal, that is, whether they exhibit consistent patterns across similar (though not identical) stimulus situations. Agreement between heart rates under the two conditions, visual sexual stimulation (VSS) and VSS + vibrotactile (VIB), was assessed using the concordance correlation coefficient (CCC). Thirty-eight men, 25 of whom were diagnosed with premature ejaculation (PE), were monitored for penile response and heart rate under two similar (though not identical) conditions: a 9-minute erotic video (VSS), then a 9-minute erotic video combined with vibrotactile penile stimulation (VSS + VIB). CCC for men with PE was 0.65; for the sexually functional comparison group, CCC was 0.82. For both groups combined, CCC was 0.71. For all groupings, the CCC was relatively high, indicating agreement in heart rate from one session to the next within individual men. Despite high intersubject variation in heart rate patterns, individual men show signature heart rates across similar sexual stimulus sessions. Such stereotypy helps explain previous inconsistent findings and may also serve as a marker for the effectiveness of treatments designed to improve ejaculatory control in men with PE. © 2011 International Society for Sexual Medicine.
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Heart-rate pulse-shift detector
NASA Technical Reports Server (NTRS)
Anderson, M.
1974-01-01
Detector circuit accurately separates and counts phase-shift pulses over wide range of basic pulse-rate frequency, and also provides reasonable representation of full repetitive EKG waveform. Single telemeter implanted in small animal monitors not only body temperature but also animal movement and heart rate.
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The heart field effect: Synchronization of healer-subject heart rates in energy therapy.
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.
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Rate of change of heart size before congestive heart failure in dogs with mitral regurgitation.
Lord, P; Hansson, K; Kvart, C; Häggström, J
2010-04-01
The objective of the study was to examine the changes in vertebral heart scale, and left atrial and ventricular dimensions before and at onset of congestive heart failure in cavalier King Charles spaniels with mitral regurgitation. Records and radiographs from 24 cavalier King Charles spaniels with mitral regurgitation were used. Vertebral heart scale (24 dogs), and left atrial dimension and left ventricular end diastolic and end systolic diameters (18 dogs) and their rate of increase were measured at intervals over years to the onset of congestive heart failure. They were plotted against time to onset of congestive heart failure. Dimensions and rates of change of all parameters were highest at onset of congestive heart failure, the difference between observed and chance outcome being highly significant using a two-tailed chi-square test (P<0.001). The left heart chambers increase in size rapidly only in the last year before the onset of congestive heart failure. Increasing left ventricular end systolic dimension is suggestive of myocardial failure before the onset of congestive heart failure. Rate of increase of heart dimensions may be a useful indicator of impending congestive heart failure.
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Hoke, Robert S; Müller-Werdan, Ursula; Lautenschläger, Christine; Werdan, Karl; Ebelt, Henning
2012-02-01
To study the association between baseline heart rate and outcome in patients with multiple organ dysfunction (MODS) as well as the course of heart rate over the first 4 days during MODS. Prospective observational study in 89 patients with MODS, defined as an APACHE-II score ≥20. Baseline heart rate (HR(0)) was determined over a 60-minute period at the time of MODS diagnosis. 28-day all-cause mortality was the primary endpoint of the study, a fall of the APACHE-II score by 4 points or more from day 0 to day 4 constituted the secondary endpoint. Hazard ratios for heart rate of 90 beats per minute (bpm) or greater relative to less than 90 bpm were calculated using Cox proportional hazards model and adjusted for confounding variables. Median baseline heart rate was 83 bpm in survivors and 92 bpm in non-survivors (p = 0.048). 28-day mortality was 32 and 61% in patients with HR(0) < 90 bpm and HR(0) ≥ 90 bpm, respectively. The adjusted hazard ratio for 28-day mortality was 2.30 (95% confidence interval 1.21-4.36, p = 0.001) for HR(0) ≥ 90 bpm relative to HR(0) < 90 bpm. No correlation was found between baseline heart rate and the secondary endpoint. From day 0 to day 4, heart rate remained elevated in all patients, as well as in survivors and non-survivors. A heart rate ≥90 bpm at the time of MODS diagnosis is an independent risk factor for increased 28-day mortality. As in patients with cardiovascular conditions such as coronary heart disease or chronic heart failure, heart rate might constitute a target for heart rate-lowering therapy in the narrow initial treatment window of MODS.
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Li, Yingxin; Zhang, Xiaoxiao; Zhang, Chen; Zhang, Xiaoying; Li, Ying; Qi, Zhao; Szeto, Christopher; Tang, Mingxin; Peng, Yizhi; Molkentin, Jeffery D; Houser, Steven R; Xie, Mingxing; Chen, Xiongwen
2018-04-01
Cav3.1 T-type Ca 2+ channel current (I Ca-T ) contributes to heart rate genesis but is not known to contribute to heart rate regulation by the sympathetic/β-adrenergic system (SAS). We show that the loss of Cav3.1 makes the beating rates of the heart in vivo and perfused hearts ex vivo, as well as sinoatrial node cells, less sensitive to β-adrenergic stimulation; it also renders less conduction acceleration through the atrioventricular node by β-adrenergic stimulation. Increasing Cav3.1 in cardiomyocytes has the opposite effects. I Ca-T in sinoatrial nodal cells can be upregulated by β-adrenergic stimulation. The results of the present study add a new contribution to heart rate regulation by the SAS system and provide potential new mechanisms for the dysregulation of heart rate and conduction by the SAS in the heart. T-type Ca 2+ channel can be a target for heart disease treatments that aim to slow down the heart rate ABSTRACT: Cav3.1 (α 1G ) T-type Ca 2+ channel (TTCC) is expressed in mouse sinoatrial node cells (SANCs) and atrioventricular (AV) nodal cells and contributes to heart rate (HR) genesis and AV conduction. However, its role in HR regulation and AV conduction acceleration by the β-adrenergic system (SAS) is unclear. In the present study, L- (I Ca-L ) and T-type (I Ca-T ) Ca 2+ currents were recorded in SANCs from Cav3.1 transgenic (TG) and knockout (KO), and control mice. I Ca-T was absent in KO SANCs but enhanced in TG SANCs. In anaesthetized animals, different doses of isoproterenol (ISO) were infused via the jugular vein and the HR was recorded. The EC 50 of the HR response to ISO was lower in TG mice but higher in KO mice, and the maximal percentage of HR increase by ISO was greater in TG mice but less in KO mice. In Langendorff-perfused hearts, ISO increased HR and shortened PR intervals to a greater extent in TG but to a less extent in KO hearts. KO SANCs had significantly slower spontaneous beating rates than control SANCs before and after
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Assessing Heart Rate in Physical Education. Assessment Series: K-12 Physical Education.
ERIC Educational Resources Information Center
Buck, Marilyn M.
This guide discusses the assessment of heart rate and, in particular, the assessment of heart rate using a heart monitor. Part 1, "Foundation for the Use of Heart Rate," reviews literature about heart rate assessment and heart rate monitors, offering an overview of national guidelines for physical activity. It focuses on the importance…
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Accuracy of Heart Rate Watches: Implications for Weight Management.
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.
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G protein-coupled estrogen receptor regulates embryonic heart rate in zebrafish
Romano, Shannon N.; Edwards, Hailey E.; Ryan, Kevin J.
2017-01-01
Estrogens act by binding to estrogen receptors alpha and beta (ERα, ERβ), ligand-dependent transcription factors that play crucial roles in sex differentiation, tumor growth and cardiovascular physiology. Estrogens also activate the G protein-coupled estrogen receptor (GPER), however the function of GPER in vivo is less well understood. Here we find that GPER is required for normal heart rate in zebrafish embryos. Acute exposure to estrogens increased heart rate in wildtype and in ERα and ERβ mutant embryos but not in GPER mutants. GPER mutant embryos exhibited reduced basal heart rate, while heart rate was normal in ERα and ERβ mutants. We detected gper transcript in discrete regions of the brain and pituitary but not in the heart, suggesting that GPER acts centrally to regulate heart rate. In the pituitary, we observed gper expression in cells that regulate levels of thyroid hormone triiodothyronine (T3), a hormone known to increase heart rate. Compared to wild type, GPER mutants had reduced levels of T3 and estrogens, suggesting pituitary abnormalities. Exposure to exogenous T3, but not estradiol, rescued the reduced heart rate phenotype in gper mutant embryos, demonstrating that T3 acts downstream of GPER to regulate heart rate. Using genetic and mass spectrometry approaches, we find that GPER regulates maternal estrogen levels, which are required for normal embryonic heart rate. Our results demonstrate that estradiol plays a previously unappreciated role in the acute modulation of heart rate during zebrafish embryonic development and suggest that GPER regulates embryonic heart rate by altering maternal estrogen levels and embryonic T3 levels. PMID:29065151
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G protein-coupled estrogen receptor regulates embryonic heart rate in zebrafish.
Romano, Shannon N; Edwards, Hailey E; Souder, Jaclyn Paige; Ryan, Kevin J; Cui, Xiangqin; Gorelick, Daniel A
2017-10-01
Estrogens act by binding to estrogen receptors alpha and beta (ERα, ERβ), ligand-dependent transcription factors that play crucial roles in sex differentiation, tumor growth and cardiovascular physiology. Estrogens also activate the G protein-coupled estrogen receptor (GPER), however the function of GPER in vivo is less well understood. Here we find that GPER is required for normal heart rate in zebrafish embryos. Acute exposure to estrogens increased heart rate in wildtype and in ERα and ERβ mutant embryos but not in GPER mutants. GPER mutant embryos exhibited reduced basal heart rate, while heart rate was normal in ERα and ERβ mutants. We detected gper transcript in discrete regions of the brain and pituitary but not in the heart, suggesting that GPER acts centrally to regulate heart rate. In the pituitary, we observed gper expression in cells that regulate levels of thyroid hormone triiodothyronine (T3), a hormone known to increase heart rate. Compared to wild type, GPER mutants had reduced levels of T3 and estrogens, suggesting pituitary abnormalities. Exposure to exogenous T3, but not estradiol, rescued the reduced heart rate phenotype in gper mutant embryos, demonstrating that T3 acts downstream of GPER to regulate heart rate. Using genetic and mass spectrometry approaches, we find that GPER regulates maternal estrogen levels, which are required for normal embryonic heart rate. Our results demonstrate that estradiol plays a previously unappreciated role in the acute modulation of heart rate during zebrafish embryonic development and suggest that GPER regulates embryonic heart rate by altering maternal estrogen levels and embryonic T3 levels.
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Procedural Pain Heart Rate Responses in Massaged Preterm Infants
Diego, Miguel A.; Field, Tiffany; Hernandez-Reif, Maria
2009-01-01
Heart rate (HR) responses to the removal of a monitoring lead were assessed in 56 preterm infants who received moderate pressure, light pressure or no massage therapy. The infants who received moderate pressure massage therapy exhibited lower increases in HR suggesting an attenuated pain response. The heart rate of infants who received moderate pressure massage also returned to baseline faster than the heart rate of the other two groups, suggesting a faster recovery rate. PMID:19185352
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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.
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Jones, Peter; Ovenden, Nick; Dauger, Stéphane; Peters, Mark J
2014-01-01
Reductions in heart rate occur frequently in children during critical care intubation and are currently considered the gold standard for haemodynamic instability. Our objective was to estimate loss of heart beats during intubation and compare this to reduction in heart rate alone whilst testing the impact of atropine pre-medication. Data were extracted from a prospective 2-year cohort study of intubation ECGs from critically ill children in PICU/Paediatric Transport. A three step algorithm was established to exclude variation in pre-intubation heart rate (using a 95%CI limit derived from pre-intubation heart rate variation of the children included), measure the heart rate over time and finally the estimate the numbers of lost beats. 333 intubations in children were eligible for inclusion of which 245 were available for analysis (74%). Intubations where the fall in heart rate was less than 50 bpm were accompanied almost exclusively by less than 25 lost beats (n = 175, median 0 [0-1]). When there was a reduction of >50 bpm there was a poor correlation with numbers of lost beats (n = 70, median 42 [15-83]). During intubation the median number of lost beats was 8 [1]-[32] when atropine was not used compared to 0 [0-0] when atropine was used (p<0.001). A reduction in heart rate during intubation of <50 bpm reliably predicted a minimal loss of beats. When the reduction in heart rate was >50 bpm the heart rate was poorly predictive of lost beats. A study looking at the relationship between lost beats and cardiac output needs to be performed. Atropine reduces both fall in heart rate and loss of beats. Similar area-under-the-curve methodology may be useful for estimating risk when biological parameters deviate outside normal range.
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Zhao, Jing; He, Fei; Hu, Da-yi; Ding, Rong-jing; Yu, Xiao-jun; Wang, Long; Zhang, Ping; Li, Xue-bin; Guo, Ji-hong; Liu, Wen-ling; Li, Cui-lan; Li, Lei; Gao, Chuan-yu; Zhao, Luo-sha; Chu, Ying-jie; Huang, Zhen-wen; Wei, Jing-han; Hua, Shao-hua; Liu, Rui-yun; Zhuang, Xiao-feng
2013-05-01
To investigate the basic characteristics of passive smoking population, and the impact of passive smoking on heart rate variability, heart rate and blood pressure. Eighty-six passive smokers [mean age: (52.4 ± 7.6) years] were recruited from patients and their relatives who visited cardiovascular outpatient department and excluded structural heart disease between June 2010 and June 2012, 80 normal subjects who were not exposed to smoking served as controls. Questionnaire survey, 24 hours ambulatory electrocardiogram examination and blood pressure measurement were performed in all recruited subjects. (1) Non-marriage rate [18.60% (16/86) vs. 3.75% (3/80), P < 0.01] was significantly higher while education level were significantly lower in passive smoking group than in control group. Passive smokers were more likely service industry workers [29.07% (25/86) vs. 15.00% (12/80), P < 0.05] and had longer daily working time [(7.56 ± 1.24) h vs. (6.02 ± 0.96) h, P < 0.01], and were less likely to be professional technology industry employers [20.93% (18/86) vs. 36.25% (29/80), P < 0.05] and managers [13.95% (12/86) vs. 38.75% (31/80), P < 0.01] compared to controls. The main place of passive smoking was workplace (67.44%, 58/86), entertainment venues (63.95%,55/86), restaurants (48.84%, 42/86). (2) Standard of the normal sinus RR intervals (SDNN), the normal consecutive sinus RR interval difference between the root-mean-square (rMSSD) and adjacent the difference between the RR interval>50 ms the number of share the percentage (PNN50) were significantly lower in passive smoking group than in the control group (all P < 0.05). Every 5 min average of the standard deviation of sinus RR cycle (SDNN index) and 24 h every 5 min sinus RR interval mean standard deviation (SDANN) were similar between the 2 groups (all P > 0.05). Ultra-low-frequency power (VLF), low frequency power (LF), high frequency power (HF) and LF/HF were significantly lower in passive smoking group than in
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Lam, Phillip H; Dooley, Daniel J; Deedwania, Prakash; Singh, Steven N; Bhatt, Deepak L; Morgan, Charity J; Butler, Javed; Mohammed, Selma F; Wu, Wen-Chih; Panjrath, Gurusher; Zile, Michael R; White, Michel; Arundel, Cherinne; Love, Thomas E; Blackman, Marc R; Allman, Richard M; Aronow, Wilbert S; Anker, Stefan D; Fonarow, Gregg C; Ahmed, Ali
2017-10-10
A lower heart rate is associated with better outcomes in patients with heart failure (HF) with reduced ejection fraction (EF). Less is known about this association in patients with HF with preserved ejection fraction (HFpEF). The aims of this study were to examine associations of discharge heart rate with outcomes in hospitalized patients with HFpEF. Of the 8,873 hospitalized patients with HFpEF (EF ≥50%) in the Medicare-linked OPTIMIZE-HF (Organized Program to Initiate Lifesaving Treatment in Hospitalized Patients with Heart Failure) registry, 6,286 had a stable heart rate, defined as ≤20 beats/min variation between admission and discharge. Of these, 2,369 (38%) had a discharge heart rate of <70 beats/min. Propensity scores for discharge heart rate <70 beats/min, estimated for each of the 6,286 patients, were used to assemble a cohort of 2,031 pairs of patients with heart rate <70 versus ≥70 beats/min, balanced on 58 baseline characteristics. The 4,062 matched patients had a mean age of 79 ± 10 years, 66% were women, and 10% were African American. During 6 years (median 2.8 years) of follow-up, all-cause mortality was 65% versus 70% for matched patients with a discharge heart rate <70 versus ≥70 beats/min, respectively (hazard ratio [HR]: 0.86; 95% confidence interval [CI]: 0.80 to 0.93; p < 0.001). A heart rate <70 beats/min was also associated with a lower risk for the combined endpoint of HF readmission or all-cause mortality (HR: 0.90; 95% CI: 0.84 to 0.96; p = 0.002), but not with HF readmission (HR: 0.93; 95% CI: 0.85 to 1.01) or all-cause readmission (HR: 1.01; 95% CI: 0.95 to 1.08). Similar associations were observed regardless of heart rhythm or receipt of beta-blockers. Among hospitalized patients with HFpEF, a lower discharge heart rate was independently associated with a lower risk of all-cause mortality, but not readmission. Published by Elsevier Inc.
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Towards Photoplethysmography-Based Estimation of Instantaneous Heart Rate During Physical Activity.
Jarchi, Delaram; Casson, Alexander J
2017-09-01
Recently numerous methods have been proposed for estimating average heart rate using photoplethysmography (PPG) during physical activity, overcoming the significant interference that motion causes in PPG traces. We propose a new algorithm framework for extracting instantaneous heart rate from wearable PPG and Electrocardiogram (ECG) signals to provide an estimate of heart rate variability during exercise. For ECG signals, we propose a new spectral masking approach which modifies a particle filter tracking algorithm, and for PPG signals constrains the instantaneous frequency obtained from the Hilbert transform to a region of interest around a candidate heart rate measure. Performance is verified using accelerometry and wearable ECG and PPG data from subjects while biking and running on a treadmill. Instantaneous heart rate provides more information than average heart rate alone. The instantaneous heart rate can be extracted during motion to an accuracy of 1.75 beats per min (bpm) from PPG signals and 0.27 bpm from ECG signals. Estimates of instantaneous heart rate can now be generated from PPG signals during motion. These estimates can provide more information on the human body during exercise. Instantaneous heart rate provides a direct measure of vagal nerve and sympathetic nervous system activity and is of substantial use in a number of analyzes and applications. Previously it has not been possible to estimate instantaneous heart rate from wrist wearable PPG signals.
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Accuracy of Heart Rate Watches: Implications for Weight Management
2016-01-01
Background 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. Aim 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. Methods 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). Results 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. Conclusion 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. PMID:27232714
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Children's Heart Rate Reactivity Responses to Three School Tasks.
ERIC Educational Resources Information Center
Sharpley, Christopher F.; And Others
1989-01-01
Investigated effects of 3 routine classroom arithmetic and reading tasks upon the heart rate reactivity of 30 fifth grade children. Results indicated that some children showed large increases in heart rates during the three tasks, and that these children should be considered at risk for coronary heart disease. (Author/TE)
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Fighter pilots' heart rate, heart rate variation and performance during instrument approaches.
Mansikka, Heikki; Simola, Petteri; Virtanen, Kai; Harris, Don; Oksama, Lauri
2016-10-01
Fighter pilots' heart rate (HR), heart rate variation (HRV) and performance during instrument approaches were examined. The subjects were required to fly instrument approaches in a high-fidelity simulator under various levels of task demand. The task demand was manipulated by increasing the load on the subjects by reducing the range at which they commenced the approach. HR and the time domain components of HRV were used as measures of pilot mental workload (PMWL). The findings of this study indicate that HR and HRV are sensitive to varying task demands. HR and HRV were able to distinguish the level of PMWL after which the subjects were no longer able to cope with the increasing task demands and their instrument landing system performance fell to a sub-standard level. The major finding was the HR/HRV's ability to differentiate the sub-standard performance approaches from the high-performance approaches. Practitioner Summary: This paper examined if HR and HRV were sensitive to varying task demands in a fighter aviation environment and if these measures were related to variations in pilot's performance.
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Heart Rate Fragmentation: A Symbolic Dynamical Approach.
Costa, Madalena D; Davis, Roger B; Goldberger, Ary L
2017-01-01
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 deceleration and vice
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Heart rate detection from an electronic weighing scale.
González-Landaeta, R; Casas, O; Pallàs-Areny, R
2007-01-01
We propose a novel technique for heart rate detection on a subject that stands 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. We have applied our method to three different weighing scales, and estimated whether their sensitivity and frequency response suited heart rate detection. Scale sensitivities were from 490 nV/V/N to 1670 nV/V/N, all had an underdamped transient response and their dynamic gain error was below 19% at 10 Hz, which are acceptable values for heart rate estimation. We also designed a pulse detection system based on off-the-shelf integrated circuits, whose gain was about 70x10(3) and able to sense force variations about 240 mN. The signal-to-noise ratio (SNR) of the main peaks of the pulse signal detected was higher than 48 dB, which is large enough to estimate the heart rate by simple signal processing methods. To validate the method, the ECG and the force signal were simultaneously recorded on 12 volunteers. The maximal error obtained from heart rates determined from these two signals was +/-0.6 beats/minute.
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Heart Rate and Electrocardiography Monitoring in Mice
Ho, David; Zhao, Xin; Gao, Shumin; Hong, Chull; Vatner, Dorothy E.; Vatner, Stephen F.
2011-01-01
The majority of current cardiovascular research involves studies in genetically engineered mouse models. The measurement of heart rate is central to understanding cardiovascular control under normal conditions, with altered autonomic tone, superimposed stress or disease states, both in wild type mice as well as those with altered genes. Electrocardiography (ECG) is the “gold standard” using either hard wire or telemetry transmission. In addition, heart rate is measured or monitored from the frequency of the arterial pressure pulse or cardiac contraction, or by pulse oximetry. For each of these techniques, discussions of materials and methods, as well as advantages and limitations are covered. However, only the direct ECG monitoring will determine not only the precise heart rates but also whether the cardiac rhythm is normal or not. PMID:21743842
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A randomised, simulated study assessing auscultation of heart rate at birth.
Voogdt, Kevin G J A; Morrison, Allison C; Wood, Fiona E; van Elburg, Ruurd M; Wyllie, Jonathan P
2010-08-01
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 resuscitation scenarios. The VitalSim((c)) manikin (Laerdal Medical, Stavanger, Norway) was used in this randomised, single blind study. Four heart rate settings (0, 40, 80, 120 beats per minute (bpm)) were randomly assigned. Participants assessed them by auscultation in three different scenarios. The first scenario was to assess the actual heart rate at birth. In the second scenario, heart rate was assessed during ventilation and assigned to standard ranges (<60, 60-100, >100bpm). In the third scenario, heart rate was assessed after three cycles of compressions and ventilation and assigned to standard ranges. In total 61 midwives, nurses and doctors performed 183 assessments. Mean time to estimate heart rate for scenarios 1, 2 and 3 was: 17.0, 9.8 and 7.8s respectively. Heart rate assessments were inaccurate in 31% (scenario 1), 28% (scenarios 2) and 26% (scenario 3). There was a trend for assessors who were accurate to be quicker and this achieved significance in scenario 2 (p<0.02). Inaccurate assessment would have made a difference to management in 28% of all cases. Mean time to estimate heart rate for the scenarios varied between 7.8 and 17.0s. Twenty-eight percent of all heart rate assessments would have prompted incorrect management during resuscitation or stabilization. Of incorrect assessments, 73% were overestimations. Further research is required to develop a rapid and accurate method for determining heart rate during newborn resuscitation. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.
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Laskey, Warren K.; Alomari, Ihab; Cox, Margueritte; Schulte, Phillip J.; Zhao, Xin; Hernandez, Adrian F.; Heidenreich, Paul A.; Eapen, Zubin J.; Yancy, Clyde; Bhatt, Deepak L.; Fonarow, Gregg C.
2015-01-01
Background Whether heart rate upon discharge following hospitalization for heart failure is associated with long‐term adverse outcomes and whether this association differs between patients with sinus rhythm (SR) and atrial fibrillation (AF) have not been well studied. Methods and Results We conducted a retrospective cohort study from clinical registry data linked to Medicare claims for 46 217 patients participating in Get With The Guidelines®–Heart Failure. Cox proportional‐hazards models were used to estimate the association between discharge heart rate and all‐cause mortality, all‐cause readmission, and the composite outcome of mortality/readmission through 1 year. For SR and AF patients with heart rate ≥75, the association between heart rate and mortality (expressed as hazard ratio [HR] per 10 beats‐per‐minute increment) was significant at 0 to 30 days (SR: HR 1.30, 95% CI 1.22 to 1.39; AF: HR 1.23, 95% CI 1.16 to 1.29) and 31 to 365 days (SR: HR 1.15, 95% CI 1.12 to 1.20; AF: HR 1.05, 95% CI 1.01 to 1.08). Similar associations between heart rate and all‐cause readmission and the composite outcome were obtained for SR and AF patients from 0 to 30 days but only in the composite outcome for SR patients over the longer term. The HR from 0 to 30 days exceeded that from 31 to 365 days for both SR and AF patients. At heart rates <75, an association was significant for mortality only for both SR and AF patients. Conclusions Among older patients hospitalized with heart failure, higher discharge heart rate was associated with increased risks of death and rehospitalization, with higher risk in the first 30 days and for SR compared with AF. PMID:25904590
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Targeting Inflammation in Heart Failure with Histone Deacetylase Inhibitors
McKinsey, Timothy A
2011-01-01
Cardiovascular insults such as myocardial infarction and chronic hypertension can trigger the heart to undergo a remodeling process characterized by myocyte hypertrophy, myocyte death and fibrosis, often resulting in impaired cardiac function and heart failure. Pathological cardiac remodeling is associated with inflammation, and therapeutic approaches targeting inflammatory cascades have shown promise in patients with heart failure. Small molecule histone deacetylase (HDAC) inhibitors block adverse cardiac remodeling in animal models, suggesting unforeseen potential for this class of compounds for the treatment of heart failure. In addition to their beneficial effects on myocardial cells, HDAC inhibitors have potent antiinflammatory actions. This review highlights the roles of HDACs in the heart and the potential for using HDAC inhibitors as broad-based immunomodulators for the treatment of human heart failure. PMID:21267510
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Monitoring nocturnal heart rate with bed sensor.
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.
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Asymmetric acceleration/deceleration dynamics in heart rate variability
NASA Astrophysics Data System (ADS)
Alvarez-Ramirez, J.; Echeverria, J. C.; Meraz, M.; Rodriguez, E.
2017-08-01
The heart rate variability (HRV) is an important physiological signal used either to assess the risk of cardiac death or to model the cardiovascular regulatory dynamics. Asymmetries in HRV data have been observed using 2D Poincare plots, which have been linked to a non-equilibrium operation of the cardiac autonomic system. This work further explores the presence of asymmetries but in the serial correlations of the dynamics of HRV data. To this end, detrended fluctuation analysis (DFA) was used to estimate the Hurst exponent both when the heart rate is accelerating and when it is decelerating. The analysis is conducted using data collected from subjects under normal sinus rhythm (NSR), congestive heart failure (CHF) and atrial fibrillation (AF) . For the NSR cases, it was found that correlations are stronger (p < 0 . 05) when the heart rate is accelerating than when it is decelerating over different scales in the range 20-40 beats. In contrast, the opposite behavior was detected for the CHF and AF patients. Possible links between asymmetric correlations in the dynamics and the mechanisms controlling the operation of the heart rate are discussed, as well as their implications for modeling the cardiovascular regulatory dynamics.
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Tőzsér, János; Szenci, Ottó; Póti, Péter; Pajor, Ferenc
2015-01-01
From the 1990s, extensive research was started on the physiological aspects of individual traits in animals. Previous research has established two extreme (proactive and reactive) coping styles in several animal species, but the means of reactivity with the autonomic nervous system (ANS) activity has not yet been investigated in cattle. The aim of this study was the characterization of cardiac autonomic activity under different conditions in cows with different individual characteristics. For this purpose, we investigated heart rate and ANS-related heart rate variability (HRV) parameters of dairy cows (N = 282) on smaller- and larger-scale farms grouped by (1) temperament and (2) behavioural reactivity to humans (BRH). Animals with high BRH scores were defined as impulsive, while animals with low BRH scores were defined as reserved. Cardiac parameters were calculated for undisturbed lying (baseline) and for milking bouts, the latter with the presence of an unfamiliar person (stressful situation). Sympathetic tone was higher, while vagal activity was lower in temperamental cows than in calm animals during rest both on smaller- and larger-scale farms. During milking, HRV parameters were indicative of a higher sympathetic and a lower vagal activity of temperamental cows as compared to calm ones in farms of both sizes. Basal heart rate did not differ between BRH groups either on smaller- or larger-scale farms. Differences between basal ANS activity of impulsive and reserved cows reflected a higher resting vagal and lower sympathetic activity of reserved animals compared to impulsive ones both on smaller- and larger-scale farms. There was no difference either in heart rate or in HRV parameters between groups during milking neither in smaller- nor in larger-scale farms. These two groupings allowed to draw possible parallels between personality and cardiac autonomic activity during both rest and milking in dairy cows. Heart rate and HRV seem to be useful for
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Mansikka, Heikki; Virtanen, Kai; Harris, Don; Simola, Petteri
2016-09-01
Increased task demand will increase the pilot mental workload (PMWL). When PMWL is increased, mental overload may occur resulting in degraded performance. During pilots' instrument flight rules (IFR) proficiency test, PMWL is typically not measured. Therefore, little is known about workload during the proficiency test and pilots' potential to cope with higher task demands than those experienced during the test. In this study, fighter pilots' performance and PMWL was measured during a real IFR proficiency test in an F/A-18 simulator. PMWL was measured using heart rate (HR) and heart rate variation (HRV). Performance was rated using Finnish Air Force's official rating scales. Results indicated that HR and HRV differentiate varying task demands in situations where variations in performance are insignificant. It was concluded that during a proficiency test, PMWL should be measured together with the task performance measurement. Copyright © 2016 Elsevier Ltd. All rights reserved.
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Validation of heart rate extraction through an iPhone accelerometer.
Kwon, Sungjun; Lee, Jeongsu; Chung, Gih Sung; Park, Kwang Suk
2011-01-01
Ubiquitous medical technology may provide advanced utility for evaluating the status of the patient beyond the clinical environment. The iPhone provides the capacity to measure the heart rate, as the iPhone consists of a 3-axis accelerometer that is sufficiently sensitive to perceive tiny body movements caused by heart pumping. In this preliminary study, an iPhone was tested and evaluated as the reliable heart rate extractor to use for medical purpose by comparing with reference electrocardiogram. By comparing the extracted heart rate from acquired acceleration data with the extracted one from ECG reference signal, iPhone functioning as the reliable heart rate extractor has demonstrated sufficient accuracy and consistency.
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Heart rates increase after hatching in two species of natricine snakes
Aubret, Fabien
2013-01-01
Experimental studies have shown heart rates to decrease from embryo to hatchling stage in turtles, remain steady in skinks, and increase in birds. However, no snake species has been studied in this regard. I recorded heart rate evolution trajectories from embryo to juvenile stage in 78 eggs from two species of European Natricine snakes. Unexpectedly, snakes behaved more like birds than turtles or lizards: heart rates increased after hatching in both N. maura and N. natrix, respectively by 43.92 ± 22.84% and 35.92 ± 24.52%. Heart rate shift was not related to an abrupt elevation of metabolism per se (snakes that increased their heart rates the most sharply grew the least after birth), but rather due to a number of smaller eggs that experienced lower than normal heart rates throughout the incubation and recovered a normal heart rate post-birth. This finding is discussed in the light of hatching synchrony benefits. PMID:24287712
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Davidovic, Goran; Iric-Cupic, Violeta; Milanov, Srdjan; Dimitijevic, Aleksandra; Petrovic-Janicijevic, Mirjana
2013-01-01
Many prospective studies established association between high heart rate and increased cardiovascular morbidity and mortality, independently of other risk factors. Heart rate over 80 beats per minute more often leads to atherosclerotic plaque disruption, the main step in developing acute coronary syndrome. Purpose was to investigate the incidence of higher heart rate levels in patients with anterior wall acute myocardial infarction with ST-segment elevation and the influence of heart rate on mortality. Research included 140 patients with anterior wall acute myocardial infarction with ST-segment elevation treated in Coronary Unit, Clinical Center Kragujevac in the period from January 2001-June 2006. Heart rate was calculated as the mean value of baseline and heart rate in the first 30 minutes after admission. Other risk factors were also followed to determine their connection with elevated heart rate. Results showed that the majority of patients survived (over 70%). In a total number of patients, more than 75% had a heart rate levels greater than 80 beats per minute. There was a significant difference in heart rate on addmision between survivors and patients who died, with a greater levels in patients with fatal outcome. Both, univariate and multivariate regression analysis singled out heart rate greater than 80 beats per minute as independent mortality predictor in these patients. Heart rate greater than 80 beats per minute is a major, independent risk factor for morbidity and important predictor of mortality in patients with acute myocardial infarction. PMID:23991346
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Phase Transition in a Healthy Human Heart Rate
NASA Astrophysics Data System (ADS)
Kiyono, Ken; Struzik, Zbigniew R.; Aoyagi, Naoko; Togo, Fumiharu; Yamamoto, Yoshiharu
2005-07-01
A healthy human heart rate displays complex fluctuations which share characteristics of physical systems in a critical state. We demonstrate that the human heart rate in healthy individuals undergoes a dramatic breakdown of criticality characteristics, reminiscent of continuous second order phase transitions. By studying the germane determinants, we show that the hallmark of criticality—highly correlated fluctuations—is observed only during usual daily activity, and a breakdown of these characteristics occurs in prolonged, strenuous exercise and sleep. This finding is the first reported discovery of the dynamical phase transition phenomenon in a biological control system and will be a key to understanding the heart rate control system in health and disease.
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Heart Rate Response in Spectators of the Montreal Canadiens Hockey Team.
Khairy, Leia T; Barin, Roxana; Demonière, Fabrice; Villemaire, Christine; Billo, Marie-Josée; Tardif, Jean-Claude; Macle, Laurent; Khairy, Paul
2017-12-01
To our knowledge, heart rate responses have not previously been assessed in hockey fans. We quantified heart rate increases in spectators of the Montreal Canadiens, compared televised with live games, explored features associated with peak heart rates, and assessed whether increases correlate with a fan passion score. Healthy adults were enrolled, with half attending live games and half viewing televised games. All subjects completed questionnaires and had continuous Holter monitoring. Intensity of the physical stress response was defined according to previously published heart rate index thresholds as mild (< 1.33), moderate (1.33-1.83), or vigorous (> 1.83). In 20 participants, 35% women, age 46 ± 10 years, the heart rate increased by a median of 92% during the hockey game, from 60 (interquartile range, 54-65) beats per minute at rest to 114 (interquartile range, 103-129) beats per minute (P < 0.001). The heart rate increased by 110% vs 75% during live vs televised games (P < 0.001). Heart rate index (2.16 ± 0.27 vs 1.73 ± 0.15; P < 0.001) and percent maximum predicted heart rate attained (75% ± 8% vs 58% ± 7%; P < 0.001) were significantly higher during live vs televised games. Number of premature beats was nonsignificantly higher during live games (5 vs 1; P = 0.181). The fan passion score was not predictive of the heart rate response (P = 0.753). Peak heart rates most commonly occurred during overtime (40%) and scoring opportunities for (25%) and against (15%). It is exciting to watch the Montreal Canadiens! Viewing a live hockey game is associated with a heart rate response equivalent to vigorous physical stress and a televised game to moderate physical stress. Copyright © 2017 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.
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Opdahl, Anders; Venkatesh, Bharath Ambale; Fernandes, Veronica R. S.; Wu, Colin O.; Nasir, Khurram; Choi, Eui-Young; Almeida, Andre L. C.; Rosen, Boaz; Carvalho, Benilton; Edvardsen, Thor; Bluemke, David A.; Lima, Joao A. C.
2014-01-01
OBJECTIVE To investigate the relationship between baseline resting heart rate and incidence of heart failure (HF) and global and regional left ventricular (LV) dysfunction. BACKGROUND The association of resting heart rate to HF and LV function is not well described in an asymptomatic multi-ethnic population. METHODS Participants in the Multi-Ethnic Study of Atherosclerosis had resting heart rate measured at inclusion. Incident HF was registered (n=176) during follow-up (median 7 years) in those who underwent cardiac MRI (n=5000). Changes in ejection fraction (ΔEF) and peak circumferential strain (Δεcc) were measured as markers of developing global and regional LV dysfunction in 1056 participants imaged at baseline and 5 years later. Time to HF (Cox model) and Δεcc and ΔEF (multiple linear regression models) were adjusted for demographics, traditional cardiovascular risk factors, calcium score, LV end-diastolic volume and mass in addition to resting heart rate. RESULTS Cox analysis demonstrated that for 1 bpm increase in resting heart rate there was a 4% greater adjusted relative risk for incident HF (Hazard Ratio: 1.04 (1.02, 1.06 (95% CI); P<0.001). Adjusted multiple regression models demonstrated that resting heart rate was positively associated with deteriorating εcc and decrease in EF, even in analyses when all coronary heart disease events were excluded from the model. CONCLUSION Elevated resting heart rate is associated with increased risk for incident HF in asymptomatic participants in MESA. Higher heart rate is related to development of regional and global LV dysfunction independent of subclinical atherosclerosis and coronary heart disease. PMID:24412444
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Evaluation of the metabolic rate based on the recording of the heart rate.
Malchaire, Jacques; d'AMBROSIO Alfano, Francesca Romana; Palella, Boris Igor
2017-06-08
The assessment of harsh working conditions requires a correct evaluation of the metabolic rate. This paper revises the basis described in the ISO 8996 standard for the evaluation of the metabolic rate at a work station from the recording of the heart rate of a worker during a representative period of time. From a review of the literature, formulas different from those given in the standard are proposed to estimate the maximum working capacity, the maximum heart rate, the heart rate and the metabolic rate at rest and the relation (HR vs. M) at the basis of the estimation of the equivalent metabolic rate, as a function of the age, height and weight of the person. A Monte Carlo simulation is used to determine, from the approximations of these parameters and formulas, the imprecision of the estimated equivalent metabolic rate. The results show that the standard deviation of this estimate varies from 10 to 15%.
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Evaluation of the metabolic rate based on the recording of the heart rate
MALCHAIRE, Jacques; ALFANO, Francesca Romana d’AMBROSIO; PALELLA, Boris Igor
2017-01-01
The assessment of harsh working conditions requires a correct evaluation of the metabolic rate. This paper revises the basis described in the ISO 8996 standard for the evaluation of the metabolic rate at a work station from the recording of the heart rate of a worker during a representative period of time. From a review of the literature, formulas different from those given in the standard are proposed to estimate the maximum working capacity, the maximum heart rate, the heart rate and the metabolic rate at rest and the relation (HR vs. M) at the basis of the estimation of the equivalent metabolic rate, as a function of the age, height and weight of the person. A Monte Carlo simulation is used to determine, from the approximations of these parameters and formulas, the imprecision of the estimated equivalent metabolic rate. The results show that the standard deviation of this estimate varies from 10 to 15%. PMID:28250334
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Effect of Selective Heart Rate Slowing in Heart Failure With Preserved Ejection Fraction.
Pal, Nikhil; Sivaswamy, Nadiya; Mahmod, Masliza; Yavari, Arash; Rudd, Amelia; Singh, Satnam; Dawson, Dana K; Francis, Jane M; Dwight, Jeremy S; Watkins, Hugh; Neubauer, Stefan; Frenneaux, Michael; Ashrafian, Houman
2015-11-03
Heart failure with preserved ejection fraction (HFpEF) is associated with significant morbidity and mortality but is currently refractory to therapy. Despite limited evidence, heart rate reduction has been advocated, on the basis of physiological considerations, as a therapeutic strategy in HFpEF. We tested the hypothesis that heart rate reduction improves exercise capacity in HFpEF. We conducted a randomized, crossover study comparing selective heart rate reduction with the If blocker ivabradine at 7.5 mg twice daily versus placebo for 2 weeks each in 22 symptomatic patients with HFpEF who had objective evidence of exercise limitation (peak oxygen consumption at maximal exercise [o2 peak] <80% predicted for age and sex). The result was compared with 22 similarly treated matched asymptomatic hypertensive volunteers. The primary end point was the change in o2 peak. Secondary outcomes included tissue Doppler-derived E/e' at echocardiography, plasma brain natriuretic peptide, and quality-of-life scores. Ivabradine significantly reduced peak heart rate compared with placebo in the HFpEF (107 versus 129 bpm; P<0.0001) and hypertensive (127 versus 145 bpm; P=0.003) cohorts. Ivabradine compared with placebo significantly worsened the change in o2 peak in the HFpEF cohort (-2.1 versus 0.9 mL·kg(-1)·min(-1); P=0.003) and significantly reduced submaximal exercise capacity, as determined by the oxygen uptake efficiency slope. No significant effects on the secondary end points were discernable. Our observations bring into question the value of heart rate reduction with ivabradine for improving symptoms in a HFpEF population characterized by exercise limitation. URL: http://www.clinicaltrials.gov. Unique identifier: NCT02354573. © 2015 The Authors.
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Discovery of novel heart rate-associated loci using the Exome Chip
van den Berg, Marten E.; Warren, Helen R.; Cabrera, Claudia P.; Verweij, Niek; Mifsud, Borbala; Haessler, Jeffrey; Bihlmeyer, Nathan A.; Fu, Yi-Ping; Weiss, Stefan; Lin, Henry J.; Grarup, Niels; Li-Gao, Ruifang; Pistis, Giorgio; Shah, Nabi; Brody, Jennifer A.; Müller-Nurasyid, Martina; Lin, Honghuang; Mei, Hao; Smith, Albert V.; Lyytikäinen, Leo-Pekka; Hall, Leanne M.; van Setten, Jessica; Trompet, Stella; Prins, Bram P.; Isaacs, Aaron; Radmanesh, Farid; Marten, Jonathan; Entwistle, Aiman; Kors, Jan A.; Silva, Claudia T.; Alonso, Alvaro; Bis, Joshua C.; de Boer, Rudolf; de Haan, Hugoline G.; de Mutsert, Renée; Dedoussis, George; Dominiczak, Anna F.; Doney, Alex S. F.; Ellinor, Patrick T.; Eppinga, Ruben N.; Felix, Stephan B.; Guo, Xiuqing; Hagemeijer, Yanick; Hansen, Torben; Harris, Tamara B.; Heckbert, Susan R.; Huang, Paul L.; Hwang, Shih-Jen; Kähönen, Mika; Kanters, Jørgen K.; Kolcic, Ivana; Launer, Lenore J.; Li, Man; Yao, Jie; Linneberg, Allan; Liu, Simin; Macfarlane, Peter W.; Mangino, Massimo; Morris, Andrew D.; Mulas, Antonella; Murray, Alison D.; Nelson, Christopher P.; Orrú, Marco; Padmanabhan, Sandosh; Peters, Annette; Porteous, David J.; Poulter, Neil; Psaty, Bruce M.; Qi, Lihong; Raitakari, Olli T.; Rivadeneira, Fernando; Roselli, Carolina; Rudan, Igor; Sattar, Naveed; Sever, Peter; Sinner, Moritz F.; Soliman, Elsayed Z.; Spector, Timothy D.; Stanton, Alice V.; Stirrups, Kathleen E.; Taylor, Kent D.; Tobin, Martin D.; Uitterlinden, André; Vaartjes, Ilonca; Hoes, Arno W.; van der Meer, Peter; Völker, Uwe; Waldenberger, Melanie; Xie, Zhijun; Zoledziewska, Magdalena; Tinker, Andrew; Polasek, Ozren; Rosand, Jonathan; Jamshidi, Yalda; van Duijn, Cornelia M.; Zeggini, Eleftheria; Jukema, J. Wouter; Asselbergs, Folkert W.; Samani, Nilesh J.; Lehtimäki, Terho; Gudnason, Vilmundur; Wilson, James; Lubitz, Steven A.; Kääb, Stefan; Sotoodehnia, Nona; Caulfield, Mark J.; Palmer, Colin N. A.; Sanna, Serena; Mook-Kanamori, Dennis O.; Deloukas, Panos; Pedersen, Oluf; Rotter, Jerome I.; Dörr, Marcus; O'Donnell, Chris J.; Hayward, Caroline; Arking, Dan E.; Kooperberg, Charles; van der Harst, Pim; Eijgelsheim, Mark; Stricker, Bruno H.; Munroe, Patricia B.
2017-01-01
Abstract 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 discover new genetic loci associated with heart rate from Exome Chip meta-analyses. Heart rate was measured from either elecrtrocardiograms or pulse recordings. We meta-analysed heart rate association results from 104 452 European-ancestry individuals from 30 cohorts, genotyped using the Exome Chip. Twenty-four variants were selected for follow-up in an independent dataset (UK Biobank, N = 134 251). Conditional and gene-based testing was undertaken, and variants were investigated with bioinformatics methods. We discovered five novel heart rate loci, and one new independent low-frequency non-synonymous variant in an established heart rate locus (KIAA1755). Lead variants in four of the novel loci are non-synonymous variants in the genes C10orf71, DALDR3, TESK2 and SEC31B. The variant at SEC31B is significantly associated with SEC31B expression in heart and tibial nerve tissue. Further candidate genes were detected from long-range regulatory chromatin interactions in heart tissue (SCD, SLF2 and MAPK8). We observed significant enrichment in DNase I hypersensitive sites in fetal heart and lung. Moreover, enrichment was seen for the first time in human neuronal progenitor cells (derived from embryonic stem cells) 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. PMID:28379579
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Discovery of novel heart rate-associated loci using the Exome Chip.
van den Berg, Marten E; Warren, Helen R; Cabrera, Claudia P; Verweij, Niek; Mifsud, Borbala; Haessler, Jeffrey; Bihlmeyer, Nathan A; Fu, Yi-Ping; Weiss, Stefan; Lin, Henry J; Grarup, Niels; Li-Gao, Ruifang; Pistis, Giorgio; Shah, Nabi; Brody, Jennifer A; Müller-Nurasyid, Martina; Lin, Honghuang; Mei, Hao; Smith, Albert V; Lyytikäinen, Leo-Pekka; Hall, Leanne M; van Setten, Jessica; Trompet, Stella; Prins, Bram P; Isaacs, Aaron; Radmanesh, Farid; Marten, Jonathan; Entwistle, Aiman; Kors, Jan A; Silva, Claudia T; Alonso, Alvaro; Bis, Joshua C; de Boer, Rudolf; de Haan, Hugoline G; de Mutsert, Renée; Dedoussis, George; Dominiczak, Anna F; Doney, Alex S F; Ellinor, Patrick T; Eppinga, Ruben N; Felix, Stephan B; Guo, Xiuqing; Hagemeijer, Yanick; Hansen, Torben; Harris, Tamara B; Heckbert, Susan R; Huang, Paul L; Hwang, Shih-Jen; Kähönen, Mika; Kanters, Jørgen K; Kolcic, Ivana; Launer, Lenore J; Li, Man; Yao, Jie; Linneberg, Allan; Liu, Simin; Macfarlane, Peter W; Mangino, Massimo; Morris, Andrew D; Mulas, Antonella; Murray, Alison D; Nelson, Christopher P; Orrú, Marco; Padmanabhan, Sandosh; Peters, Annette; Porteous, David J; Poulter, Neil; Psaty, Bruce M; Qi, Lihong; Raitakari, Olli T; Rivadeneira, Fernando; Roselli, Carolina; Rudan, Igor; Sattar, Naveed; Sever, Peter; Sinner, Moritz F; Soliman, Elsayed Z; Spector, Timothy D; Stanton, Alice V; Stirrups, Kathleen E; Taylor, Kent D; Tobin, Martin D; Uitterlinden, André; Vaartjes, Ilonca; Hoes, Arno W; van der Meer, Peter; Völker, Uwe; Waldenberger, Melanie; Xie, Zhijun; Zoledziewska, Magdalena; Tinker, Andrew; Polasek, Ozren; Rosand, Jonathan; Jamshidi, Yalda; van Duijn, Cornelia M; Zeggini, Eleftheria; Jukema, J Wouter; Asselbergs, Folkert W; Samani, Nilesh J; Lehtimäki, Terho; Gudnason, Vilmundur; Wilson, James; Lubitz, Steven A; Kääb, Stefan; Sotoodehnia, Nona; Caulfield, Mark J; Palmer, Colin N A; Sanna, Serena; Mook-Kanamori, Dennis O; Deloukas, Panos; Pedersen, Oluf; Rotter, Jerome I; Dörr, Marcus; O'Donnell, Chris J; Hayward, Caroline; Arking, Dan E; Kooperberg, Charles; van der Harst, Pim; Eijgelsheim, Mark; Stricker, Bruno H; Munroe, Patricia B
2017-06-15
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 discover new genetic loci associated with heart rate from Exome Chip meta-analyses.Heart rate was measured from either elecrtrocardiograms or pulse recordings. We meta-analysed heart rate association results from 104 452 European-ancestry individuals from 30 cohorts, genotyped using the Exome Chip. Twenty-four variants were selected for follow-up in an independent dataset (UK Biobank, N = 134 251). Conditional and gene-based testing was undertaken, and variants were investigated with bioinformatics methods.We discovered five novel heart rate loci, and one new independent low-frequency non-synonymous variant in an established heart rate locus (KIAA1755). Lead variants in four of the novel loci are non-synonymous variants in the genes C10orf71, DALDR3, TESK2 and SEC31B. The variant at SEC31B is significantly associated with SEC31B expression in heart and tibial nerve tissue. Further candidate genes were detected from long-range regulatory chromatin interactions in heart tissue (SCD, SLF2 and MAPK8). We observed significant enrichment in DNase I hypersensitive sites in fetal heart and lung. Moreover, enrichment was seen for the first time in human neuronal progenitor cells (derived from embryonic stem cells) 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. © The Author 2017. Published by Oxford University Press.
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Heart rate and respiratory rhythm dynamics on ascent to high altitude
NASA Technical Reports Server (NTRS)
Lipsitz, L. A.; Hashimoto, F.; Lubowsky, L. P.; Mietus, J.; Moody, G. B.; Appenzeller, O.; Goldberger, A. L.
1995-01-01
OBJECTIVE--To investigate the alterations in autonomic control of heart rate at high altitude and to test the hypothesis that hypoxaemic stress during exposure to high altitude induces non-linear, periodic heart rate oscillations, similar to those seen in heart failure and the sleep apnoea syndrome. SUBJECTS--11 healthy subjects aged 24-64. MAIN OUTCOME MEASURES--24 hour ambulatory electrocardiogram records obtained at baseline (1524 m) and at 4700 m. Simultaneous heart rate and respiratory dynamics during 2.5 hours of sleep by fast Fourier transform analysis of beat to beat heart rate and of an electrocardiographically derived respiration signal. RESULTS--All subjects had resting hypoxaemia at high altitude, with an average oxyhaemoglobin saturation of 81% (5%). There was no significant change in mean heart rate, but low frequency (0.01-0.05 Hz) spectral power was increased (P < 0.01) at high altitude. Time series analysis showed a complex range of non-linear sinus rhythm dynamics. Striking low frequency (0.04-0.06 Hz) heart rate oscillations were observed during sleep in eight subjects at high altitude. Analysis of the electrocardiographically derived respiration signal indicated that these heart rate oscillations correlated with low frequency respiratory oscillations. CONCLUSIONS--These data suggest (a) that increased low frequency power during high altitude exposure is not simply attributable to increased sympathetic modulation of heart rate, but relates to distinctive cardiopulmonary oscillations at approximately 0.05 Hz and (b) that the emergence of periodic heart rate oscillations at high altitude is consistent with an unstable cardiopulmonary control system that may develop on acute exposure to hypoxaemic stress.
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Respiration-rate estimation of a moving target using impulse-based ultra wideband radars.
Sharafi, Azadeh; Baboli, Mehran; Eshghi, Mohammad; Ahmadian, Alireza
2012-03-01
Recently, Ultra-wide band signals have become attractive for their particular advantage of having high spatial resolution and good penetration ability which makes them suitable in medical applications. One of these applications is wireless detection of heart rate and respiration rate. Two hypothesis of static environment and fixed patient are considered in the method presented in previous literatures which are not valid for long term monitoring of ambulant patients. In this article, a new method to detect the respiration rate of a moving target is presented. The first algorithm is applied to the simulated and experimental data for detecting respiration rate of a fixed target. Then, the second algorithm is developed to detect respiration rate of a moving target. The proposed algorithm uses correlation for body movement cancellation, and then detects the respiration rate based on energy in frequency domain. The results of algorithm prove an accuracy of 98.4 and 97% in simulated and experimental data, respectively.
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Heart rate response to submaximal and maximal workloads during running and swimming.
Hauber, C; Sharp, R L; Franke, W D
1997-07-01
The purpose of the present study was to determine if common indexes of exercise intensity, assessed with land-based exercise, could be applied to swimming. Consequently, the heart rate (HR) and oxygen uptake (VO2) responses to submaximal and maximal treadmill running (TR) and free swimming (SW) in 11 fitness swimmers were assessed to determine if the responses to TR could be used to predict those of SW. A maximal graded exercise test using a discontinuous protocol was used for TR, while four graded submaximal 200 yd swims and one 400 yd maximal swim was used for SW. Rest periods were similar for each mode. Significantly lower (p < 0.05) peak values were found in SW compared to TR for both HR (174 +/- 3 vs 183 +/- 3 bt x min(-1)) and VO2 (3.58 +/- 0.18 vs 3.97 +/- 0.22 L x min(-1)), SW vs TR; +/- SE, respectively. However, regression analyses of submaximal HR vs VO2 for each subject revealed similar slopes for TR and SW (30.5 +/- 1.7 vs 29.9 +/- 3.5 bt x L(-1), p > 0.05) and similar intercepts (67.3 +/- 2.6 vs 66.5 +/- 11.5 bt x min(-1), p > 0.05). At the VO2 equivalent to 50% treadmill VO2max, the heart rate predicted from SW did not differ significantly from TR (118 +/- 5 vs 124 +/- 1 bt x min(-1), p > 0.05). This was also true at 85% treadmill VO2max (171 +/- 4 vs 166 +/- 3 bt x min(-1), SW vs TR, respectively; p > 0.05). These data suggest that peak heart rate and oxygen uptake appear to be mode specific, but exercising at a given submaximal oxygen uptake will elicit a similar heart rate regardless of the mode. Thus, target heart rate ranges designed for land-based exercise appear to be appropriate for fitness swimmers during swimming.
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Robust sensor fusion of unobtrusively measured heart rate.
Wartzek, Tobias; Brüser, Christoph; Walter, Marian; Leonhardt, Steffen
2014-03-01
Contactless vital sign measurement technologies often have the drawback of severe motion artifacts and periods in which no signal is available. However, using several identical or physically different sensors, redundancy can be used to decrease the error in noncontact heart rate estimation, while increasing the time period during which reliable data are available. In this paper, we show for the first time two major results in case of contactless heart rate measurements deduced from a capacitive ECG and optical pulse signals. First, an artifact detection is an essential preprocessing step to allow a reliable fusion. Second, the robust but computationally efficient median already provides good results; however, using a Bayesian approach, and a short time estimation of the variance, best results in terms of difference to reference heart rate and temporal coverage can be achieved. In this paper, six sensor signals were used and coverage increased from 0-90% to 80-94%, while the difference between the estimated heart rate and the gold standard was less than ±2 BPM.
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Tobón, Diana P.; Jayaraman, Srinivasan
2017-01-01
The last few years has seen a proliferation of wearable electrocardiogram (ECG) devices in the market with applications in fitness tracking, patient monitoring, athletic performance assessment, stress and fatigue detection, and biometrics, to name a few. The majority of these applications rely on the computation of the heart rate (HR) and the so-called heart rate variability (HRV) index via time-, frequency-, or non-linear-domain approaches. Wearable/portable devices, however, are highly susceptible to artifacts, particularly those resultant from movement. These artifacts can hamper HR/HRV measurement, thus pose a serious threat to cardiac monitoring applications. While current solutions rely on ECG enhancement as a pre-processing step prior to HR/HRV calculation, existing artifact removal algorithms still perform poorly under extremely noisy scenarios. To overcome this limitation, we take an alternate approach and propose the use of a spectro-temporal ECG signal representation that we show separates cardiac components from artifacts. More specifically, by quantifying the rate-of-change of ECG spectral components over time, we show that heart rate estimates can be reliably obtained even in extremely noisy signals, thus bypassing the need for ECG enhancement. With such HR measurements in hands, we then propose a new noise-robust HRV index termed MD-HRV (modulation-domain HRV) computed as the standard deviation of the obtained HR values. Experiments with synthetic ECG signals corrupted at various different signal-to-noise levels, as well as recorded noisy signals show the proposed measure outperforming several HRV benchmark parameters computed post wavelet-based enhancement. These findings suggest that the proposed HR measures and derived MD-HRV metric are well-suited for ambulant cardiac monitoring applications, particularly those involving intense movement (e.g., elite athletic training). PMID:29255653
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Ordinal pattern statistics for the assessment of heart rate variability
NASA Astrophysics Data System (ADS)
Graff, G.; Graff, B.; Kaczkowska, A.; Makowiec, D.; Amigó, J. M.; Piskorski, J.; Narkiewicz, K.; Guzik, P.
2013-06-01
The recognition of all main features of a healthy heart rhythm (the so-called sinus rhythm) is still one of the biggest challenges in contemporary cardiology. Recently the interesting physiological phenomenon of heart rate asymmetry has been observed. This phenomenon is related to unbalanced contributions of heart rate decelerations and accelerations to heart rate variability. In this paper we apply methods based on the concept of ordinal pattern to the analysis of electrocardiograms (inter-peak intervals) of healthy subjects in the supine position. This way we observe new regularities of the heart rhythm related to the distribution of ordinal patterns of lengths 3 and 4.
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Heart rate variability alterations in late life depression: A meta-analysis.
Brown, Lydia; Karmakar, Chandan; Gray, Richard; Jindal, Ripu; Lim, Terrence; Bryant, Christina
2018-08-01
There is strong evidence for a bi-directional relationship between heart-health and depression in later life, but the physiological mechanisms underlying this relationship remain unclear. Heart rate variability is one promising factor that might help explain this relationship. We present results of a meta-analysis that considers heart rate variability alterations in older adults with depression. Literature search of Embase, PsychInfo and Medline revealed five clinical studies and six observational studies that examined the relationship between heart rate variability and depression in adults with a mean age over 60. These studies were included in this meta-analysis. Heart rate variability was reduced among older adults with clinical depression (N = 550), relative to healthy controls (Hedges' g = -0.334, 95%CI [-0.579, -0.090], p = .007). When high-frequency and low-frequency heart rate variability were investigated separately, only low-frequency heart rate variability was significantly reduced in depressed patients (Hedges' g = -0.626, 95%CI [-1.083, -0.169], p = .007). A similar but weaker pattern of results was found in the observational studies. Most findings remained significant among unmedicated depressed older adults. Evidence of effect-size heterogeneity was found in the clinical studies, indicating the need for more well-designed research in the area. Heart rate variability is reduced among older adults with depression, and this effect is not fully attributable to antidepressant medication use. Specifically, low-frequency heart rate variability may be reduced in depressed older adults. Heart rate variability warrants further attention, as it could help inform research into the prevention and treatment of depression in later life. Copyright © 2018 Elsevier B.V. All rights reserved.
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Heart rate and respiratory rhythm dynamics on ascent to high altitude.
Lipsitz, L. A.; Hashimoto, F.; Lubowsky, L. P.; Mietus, J.; Moody, G. B.; Appenzeller, O.; Goldberger, A. L.
1995-01-01
OBJECTIVE--To investigate the alterations in autonomic control of heart rate at high altitude and to test the hypothesis that hypoxaemic stress during exposure to high altitude induces non-linear, periodic heart rate oscillations, similar to those seen in heart failure and the sleep apnoea syndrome. SUBJECTS--11 healthy subjects aged 24-64. MAIN OUTCOME MEASURES--24 hour ambulatory electrocardiogram records obtained at baseline (1524 m) and at 4700 m. Simultaneous heart rate and respiratory dynamics during 2.5 hours of sleep by fast Fourier transform analysis of beat to beat heart rate and of an electrocardiographically derived respiration signal. RESULTS--All subjects had resting hypoxaemia at high altitude, with an average oxyhaemoglobin saturation of 81% (5%). There was no significant change in mean heart rate, but low frequency (0.01-0.05 Hz) spectral power was increased (P < 0.01) at high altitude. Time series analysis showed a complex range of non-linear sinus rhythm dynamics. Striking low frequency (0.04-0.06 Hz) heart rate oscillations were observed during sleep in eight subjects at high altitude. Analysis of the electrocardiographically derived respiration signal indicated that these heart rate oscillations correlated with low frequency respiratory oscillations. CONCLUSIONS--These data suggest (a) that increased low frequency power during high altitude exposure is not simply attributable to increased sympathetic modulation of heart rate, but relates to distinctive cardiopulmonary oscillations at approximately 0.05 Hz and (b) that the emergence of periodic heart rate oscillations at high altitude is consistent with an unstable cardiopulmonary control system that may develop on acute exposure to hypoxaemic stress. PMID:7488453
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Heart rate and heart rate variability modification in chronic insomnia patients.
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.
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Caveolins: targeting pro-survival signaling in the heart and brain
Stary, Creed M.; Tsutsumi, Yasuo M.; Patel, Piyush M.; Head, Brian P.; Patel, Hemal H.; Roth, David M.
2012-01-01
The present review discusses intracellular signaling moieties specific to membrane lipid rafts (MLRs) and the scaffolding proteins caveolin and introduces current data promoting their potential role in the treatment of pathologies of the heart and brain. MLRs are discreet microdomains of the plasma membrane enriched in gylcosphingolipids and cholesterol that concentrate and localize signaling molecules. Caveolin proteins are necessary for the formation of MLRs, and are responsible for coordinating signaling events by scaffolding and enriching numerous signaling moieties in close proximity. Specifically in the heart and brain, caveolins are necessary for the cytoprotective phenomenon termed ischemic and anesthetic preconditioning. Targeted overexpression of caveolin in the heart and brain leads to induction of multiple pro-survival and pro-growth signaling pathways; thus, caveolins represent a potential novel therapeutic target for cardiac and neurological pathologies. PMID:23060817
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Novel therapeutic strategies targeting fibroblasts and fibrosis in heart disease
Gourdie, Robert G.; Dimmeler, Stefanie; Kohl, Peter
2016-01-01
Our understanding of cardiac fibroblast functions has moved beyond their roles in heart structure and extracellular matrix generation, and now includes contributions to paracrine, mechanical and electrical signalling during ontogenesis and normal cardiac activity. Fibroblasts have central roles in pathogenic remodelling during myocardial ischaemia, hypertension and heart failure. As key contributors to scar formation, they are crucial for tissue repair after interventions including surgery and ablation. Novel experimental approaches targeting cardiac fibroblasts are promising potential therapies for heart disease. Indeed, several existing drugs act, at least partially, through effects on cardiac connective tissue. This Review outlines the origins and roles of fibroblasts in cardiac development, homeostasis and disease; illustrates the involvement of fibroblasts in current and emerging clinical interventions; and identifies future targets for research and development. PMID:27339799
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Bidargaddi, Niranjan; Sarela, Antti; Korhonen, Ilkka
2008-01-01
The objective is to identify whether it is possible to discriminate between normal and abnormal physiological state based on heart rate (HR), heart rate variability (HRV) and movement activity information in subjects with cardiovascular complications. HR, HRV and movement information were obtained from cardiac patients over a period of 6 weeks using an ambulatory activity and single lead ECG monitor. By applying k-means clustering on HR, HRV and movement information obtained from cardiac patients, we obtained 3 clusters in inactive state and one cluster in active state. Two clusters in inactive state characterized by - a) high HR and low HRV b) low HRV and low HR, could be inferred as pathological with abnormal autonomic function. Further, activity information was significant in differentiating between the normal cluster found in active and an abnormal cluster found in inactive states, both with low HRV. This indicates that the activity information must be taken into account while interpreting HR and HRV information.
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Cubbon, Richard M; Ruff, Naomi; Groves, David; Eleuteri, Antonio; Denby, Christine; Kearney, Lorraine; Ali, Noman; Walker, Andrew M N; Jamil, Haqeel; Gierula, John; Gale, Chris P; Batin, Phillip D; Nolan, James; Shah, Ajay M; Fox, Keith A A; Sapsford, Robert J; Witte, Klaus K; Kearney, Mark T
2016-01-01
Objective We aimed to define the prognostic value of the heart rate range during a 24 h period in patients with chronic heart failure (CHF). Methods Prospective observational cohort study of 791 patients with CHF associated with left ventricular systolic dysfunction. Mode-specific mortality and hospitalisation were linked with ambulatory heart rate range (AHRR; calculated as maximum minus minimum heart rate using 24 h Holter monitor data, including paced and non-sinus complexes) in univariate and multivariate analyses. Findings were then corroborated in a validation cohort of 408 patients with CHF with preserved or reduced left ventricular ejection fraction. Results After a mean 4.1 years of follow-up, increasing AHRR was associated with reduced risk of all-cause, sudden, non-cardiovascular and progressive heart failure death in univariate analyses. After accounting for characteristics that differed between groups above and below median AHRR using multivariate analysis, AHRR remained strongly associated with all-cause mortality (HR 0.991/bpm increase in AHRR (95% CI 0.999 to 0.982); p=0.046). AHRR was not associated with the risk of any non-elective hospitalisation, but was associated with heart-failure-related hospitalisation. AHRR was modestly associated with the SD of normal-to-normal beats (R2=0.2; p<0.001) and with peak exercise-test heart rate (R2=0.33; p<0.001). Analysis of the validation cohort revealed AHRR to be associated with all-cause and mode-specific death as described in the derivation cohort. Conclusions AHRR is a novel and readily available prognosticator in patients with CHF, which may reflect autonomic tone and exercise capacity. PMID:26674986
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Exaggerated heart rate oscillations during two meditation techniques.
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.
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Association of heart rate profile during exercise with the severity of coronary artery disease.
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
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Heart Rate Variability During Early Adaptation to Space
NASA Technical Reports Server (NTRS)
Toscano, W. B.; Cowings, P. S.
1994-01-01
A recent report hypothesized that episodes of space motion sickness (SMS) were reliably associated with low frequency oscillations (less than 0.03 to less than 0.01 Hz) in heart rate variability. This paper archives a large data set for review of investigators in this field which may facilitate the evaluation of this hypothesis. Continuous recording of Electro-cardiography (ECG) and other measures were made for 6 to 12 hours per day (waking hours) of six Shuttle crewmembers for the first 3 mission days of two separate Shuttle flights. Spectral analyses of heart rate variability during approximately 200 hours of inflight is presented. In addition, nearly 200 hours of data collected on these same individuals during ground tests prior to the mission are presented. The Purpose of this Publication is to document the incidence of low frequency oscillations of heart rate in 4 people exposed to microgravity over a period of five days. In addition, this report contains spectral analyses of heart rate data collected on these same individuals during ground-based mission simulations. By archiving these data in this manner, it is our intention to make this information available to other investigators interested in studying this phenomena.
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Randomised controlled trial of intrapartum fetal heart rate monitoring.
Mahomed, K; Nyoni, R; Mulambo, T; Kasule, J; Jacobus, E
1994-02-19
To compare effectiveness of different methods of monitoring intrapartum fetal heart rate. Prospective randomised controlled trial. Referral maternity hospital, Harare, Zimbabwe. 1255 women who were 37 weeks or more pregnant with singleton cephalic presentation and normal fetal heart rate before entry into study. Intermittent monitoring of fetal heart rate by electronic monitoring, Doppler ultrasound, use of Pinard stethoscope by a research midwife, or routine use of Pinard stethoscope by attending midwife. Abnormal fetal heart rate patterns, need for operative delivery for fetal distress, neonatal mortality, Apgar scores, admission to neonatal unit, neonatal seizures, and hypoxic ischaemic encephalopathy. Abnormalities in fetal heart rate were detected in 54% (172/318) of the electronic monitoring group, 32% (100/312) of the ultrasonography group, 15% (47/310) of the Pinard stethoscope group, and 9% (28/315) of the routine monitoring group. Caesarean sections were performed for 28% (89%), 24% (76), 10% (32), and 15% (46) of the four groups respectively. Neonatal outcome was best in the ultrasonography group: hypoxic ischaemic encephalopathy occurred in two, one, seven, and 10 cases in the four groups respectively; neonatal seizures occurred only in the last two groups (six and nine cases respectively); and deaths occurred in eight, two, five, and nine cases respectively. Abnormalities in fetal heart rate were more reliably detected by Doppler ultrasonography than with Pinard stethoscope, and its use resulted in good perinatal outcome. The use of relatively cheap ultrasound monitors should be further evaluated and promoted in obstetric units caring for high risk pregnancies in developing countries with scarce resources.
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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
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Algorithm for heart rate extraction in a novel wearable acoustic sensor
Imtiaz, Syed Anas; Aguilar–Pelaez, Eduardo; Rodriguez–Villegas, Esther
2015-01-01
Phonocardiography is a widely used method of listening to the heart sounds and indicating the presence of cardiac abnormalities. Each heart cycle consists of two major sounds – S1 and S2 – that can be used to determine the heart rate. The conventional method of acoustic signal acquisition involves placing the sound sensor at the chest where this sound is most audible. Presented is a novel algorithm for the detection of S1 and S2 heart sounds and the use of them to extract the heart rate from signals acquired by a small sensor placed at the neck. This algorithm achieves an accuracy of 90.73 and 90.69%, with respect to heart rate value provided by two commercial devices, evaluated on more than 38 h of data acquired from ten different subjects during sleep in a pilot clinical study. This is the largest dataset for acoustic heart sound classification and heart rate extraction in the literature to date. The algorithm in this study used signals from a sensor designed to monitor breathing. This shows that the same sensor and signal can be used to monitor both breathing and heart rate, making it highly useful for long-term wearable vital signs monitoring. PMID:26609401
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Lam, Phillip H; Dooley, Daniel J; Fonarow, Gregg C; Butler, Javed; Bhatt, Deepak L; Filippatos, Gerasimos S; Deedwania, Prakash; Forman, Daniel E; White, Michel; Fletcher, Ross D; Arundel, Cherinne; Blackman, Marc R; Adamopoulos, Chris; Kanonidis, Ioannis E; Aban, Inmaculada B; Patel, Kanan; Aronow, Wilbert S; Allman, Richard M; Anker, Stefan D; Pitt, Bertram; Ahmed, Ali
2018-02-01
To examine associations of below-target and target dose of enalapril, an angiotensin-converting enzyme (ACE) inhibitor, with outcomes in patients with heart failure and reduced ejection fraction (HFrEF) in the Studies of Left Ventricular Dysfunction (SOLVD) Treatment trial. Two thousand five hundred and sixty-nine patients with HFrEF (ejection fraction ≤35%) were randomized to below-target (5-10 mg/day) dose placebo (n = 1284) or enalapril (n = 1285). One month post-randomization, blind up-titration to target (20 mg/day) dose was attempted for both study drugs in 2458 patients. Among the 1444 patients who achieved dose up-titration (placebo, n = 748; enalapril, n = 696; mean dose for both groups, 20.0 mg/day), target dose enalapril (vs. target dose placebo) was associated with a 9% absolute lower risk of the combined endpoint of heart failure hospitalization or all-cause mortality [adjusted hazard ratio (HR) 0.70; 95% confidence interval (CI) 0.60-0.81; P < 0.001] during 4 years of follow-up. Among the 1014 patients who could not achieve target dose (placebo, n = 486; enalapril, n = 528; mean dose for both groups, 8.8 mg/day), below-target dose enalapril (vs. below-target dose placebo) was associated with a 12% absolute lower risk of the combined endpoint of heart failure hospitalization or all-cause mortality (adjusted HR 0.68; 95% CI 0.57-0.81; P < 0.001). Among the 1224 patients receiving enalapril, target (vs. below-target) dose had no association with the combined endpoint of heart failure hospitalization or all-cause mortality (adjusted HR 1.04; 95% CI 0.87-1.23; P = 0.695). In patients with HFrEF, the clinical benefits of ACE inhibitors appear to be similar at both below-target and target doses. © 2017 The Authors. European Journal of Heart Failure © 2017 European Society of Cardiology.
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Bluetooth Heart Rate Monitors For Spaceflight
NASA Technical Reports Server (NTRS)
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
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Cubbon, Richard M; Ruff, Naomi; Groves, David; Eleuteri, Antonio; Denby, Christine; Kearney, Lorraine; Ali, Noman; Walker, Andrew M N; Jamil, Haqeel; Gierula, John; Gale, Chris P; Batin, Phillip D; Nolan, James; Shah, Ajay M; Fox, Keith A A; Sapsford, Robert J; Witte, Klaus K; Kearney, Mark T
2016-02-01
We aimed to define the prognostic value of the heart rate range during a 24 h period in patients with chronic heart failure (CHF). Prospective observational cohort study of 791 patients with CHF associated with left ventricular systolic dysfunction. Mode-specific mortality and hospitalisation were linked with ambulatory heart rate range (AHRR; calculated as maximum minus minimum heart rate using 24 h Holter monitor data, including paced and non-sinus complexes) in univariate and multivariate analyses. Findings were then corroborated in a validation cohort of 408 patients with CHF with preserved or reduced left ventricular ejection fraction. After a mean 4.1 years of follow-up, increasing AHRR was associated with reduced risk of all-cause, sudden, non-cardiovascular and progressive heart failure death in univariate analyses. After accounting for characteristics that differed between groups above and below median AHRR using multivariate analysis, AHRR remained strongly associated with all-cause mortality (HR 0.991/bpm increase in AHRR (95% CI 0.999 to 0.982); p=0.046). AHRR was not associated with the risk of any non-elective hospitalisation, but was associated with heart-failure-related hospitalisation. AHRR was modestly associated with the SD of normal-to-normal beats (R(2)=0.2; p<0.001) and with peak exercise-test heart rate (R(2)=0.33; p<0.001). Analysis of the validation cohort revealed AHRR to be associated with all-cause and mode-specific death as described in the derivation cohort. AHRR is a novel and readily available prognosticator in patients with CHF, which may reflect autonomic tone and exercise capacity. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/
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Behavioral correlates of heart rates of free-living Greater White-fronted Geese
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 < 10 sec. During agonistic encounters, heart rate exceeded 400 BPM; heart rates during social interactions were not predictable solely from postures, as heart rates were context-dependent, and were highest in initial encounters among individuals. Instantaneous measures of physiological parameters, such as heart rate, are often better indicators of the degree of response to external stimuli than visual observations and can be used to improve estimates of energy expenditure based solely on activity data.
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Is the normal heart rate ``chaotic'' due to respiration?
NASA Astrophysics Data System (ADS)
Wessel, Niels; Riedl, Maik; Kurths, Jürgen
2009-06-01
The incidence of cardiovascular diseases increases with the growth of the human population and an aging society, leading to very high expenses in the public health system. Therefore, it is challenging to develop sophisticated methods in order to improve medical diagnostics. The question whether the normal heart rate is chaotic or not is an attempt to elucidate the underlying mechanisms of cardiovascular dynamics and therefore a highly controversial topical challenge. In this contribution we demonstrate that linear and nonlinear parameters allow us to separate completely the data sets of the three groups provided for this controversial topic in nonlinear dynamics. The question whether these time series are chaotic or not cannot be answered satisfactorily without investigating the underlying mechanisms leading to them. We give an example of the dominant influence of respiration on heart beat dynamics, which shows that observed fluctuations can be mostly explained by respiratory modulations of heart rate and blood pressure (coefficient of determination: 96%). Therefore, we recommend reformulating the following initial question: "Is the normal heart rate chaotic?" We rather ask the following: "Is the normal heart rate `chaotic' due to respiration?"
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Heart rate and treatment effect in children with disruptive behavior disorders.
Stadler, Christina; Grasmann, Dörte; Fegert, Jörg M; Holtmann, Martin; Poustka, Fritz; Schmeck, Klaus
2008-09-01
To examine whether children with disruptive behavior disorders (DBDs; hyperkinetic conduct disorder, conduct disorder, hyperkinetic disorder) characterized by low heart rate profit less from an intensive cognitive behavioral intervention aimed at reducing impulsive, oppositional and aggressive behavior problems. Basal heart rate was studied in twenty-three children (aged 7-12 years) with DBD at the beginning of intervention comprising an intensive day-care treatment and parent training. The disruptive behavior of the child was assessed before treatment and after termination (12 weeks later). Therapy responders and non-responders were compared in regard to heart rate and other risk factors (cognitive functioning and socio-economic status). Statistical analyses yielded evidence for a significant reduction of disruptive problem behaviors (aggression, delinquency) that is more prominent in DBD children with high heart rate scores compared to patients with low heart rate scores. Heart rate was significantly lower in children who did not profit from therapy. A logistic regression analysis revealed that heart rate is a significant predictor for therapy success whereas other risk factors had no impact on therapy success. Further studies investigating biological and psychosocial predictors of treatment effectiveness are necessary. In addition, it might be helpful to consider different subtypes of aggressive behavior for selecting the best possible treatment options.
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Caffeine Consumption and Heart Rate and Blood Pressure Response to Regadenoson
Bitar, Abbas; Mastouri, Ronald; Kreutz, Rolf P.
2015-01-01
Background Current guidelines recommend that caffeinated products should be avoided for at least 12 hours prior to regadenoson administration. We intended to examine the effect of caffeine consumption and of timing of last dose on hemodynamic effects after regadenoson administration for cardiac stress testing. Methods 332 subjects undergoing regadenoson stress testing were enrolled. Baseline characteristics, habits of coffee/caffeine exposure, baseline vital signs and change in heart rate, blood pressure, percent of maximal predicted heart rate, and percent change in heart rate were prospectively collected. Results Non-coffee drinkers (group 1) (73 subjects) and subjects who last drank coffee >24 hours (group 3) (139 subjects) prior to regadenoson did not demonstrate any difference in systolic blood pressure, heart rate change, maximal predicted heart rate and percent change in heart rate. Systolic blood pressure change (15.2±17.1 vs. 7.2±10.2 mmHg, p = 0.001), heart rate change (32.2±14 vs. 27.3±9.6 bpm, p = 0.038) and maximal predicted heart rate (65.5±15.6 vs. 60.7±8.6%, p = 0.038) were significantly higher in non-coffee drinkers (group 1) compared to those who drank coffee 12–24 hours prior (group 2) (108 subjects). Subjects who drank coffee >24 hours prior (group 3) exhibited higher systolic blood pressure change (13±15.8 vs. 7±10.2, p = 0.007), and heart rate change (32.1±15.3 vs. 27.3±9.6, p = 0.017) as compared to those who drank coffee 12–24 hours prior to testing (group 2). Conclusions Caffeine exposure 12–24 hours prior to regadenoson administration attenuates the vasoactive effects of regadenoson, as evidenced by a blunted rise in heart rate and systolic blood pressure. These results suggest that caffeine exposure within 24 hours may reduce the effects of regadenoson administered for vasodilatory cardiac stress testing. PMID:26098883
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Park, Sung Wook; Brenneman, Michael; Cooke, William H; Cordova, Alberto; Fogt, Donovan
The purpose was to determine if heart rate (HR) and heart rate variability (HRV) responses would reflect anaerobic threshold (AT) using a discontinuous, incremental, cycle test. AT was determined by ventilatory threshold (VT). Cyclists (30.6±5.9y; 7 males, 8 females) completed a discontinuous cycle test consisting of 7 stages (6 min each with 3 min of rest between). Three stages were performed at power outputs (W) below those corresponding to a previously established AT, one at W corresponding to AT, and 3 at W above those corresponding to AT. The W at the intersection of the trend lines was considered each metric's "threshold". The averaged stage data for Ve, HR, and time- and frequency-domain HRV metrics were plotted versus W. The W at the "threshold" for the metrics of interest were compared using correlation analysis and paired-sample t -test. In all, several heart rate-related parameters accurately reflected AT with significant correlations (p≤0.05) were observed between AT W and HR, mean RR interval (MRR), low and high frequency spectral energy (LF and HR, respectively), high frequency peak (fHF), and HFxfHF metrics' threshold W (i.e., MRRTW, etc.). Differences in HR or HRV metric threshold W and AT for all subjects were less than 14 W. The steady state data from discontinuous protocols may allow for a true indication of steady-state physiologic stress responses and corresponding W at AT, compared to continuous protocols using 1-2 min exercise stages.
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Yaylalı, Yalın Tolga; Fındıkoğlu, Gülin; Yurtdaş, Mustafa; Konukçu, Sibel; Şenol, Hande
2015-09-01
It is unclear which exercise training protocol yields superior heart rate recovery (HRR) improvement in heart failure (HF) patients. Whether baseline HRR normality plays a role in the improvement is unknown. We hypothesized that an exercise training protocol and baseline HRR normality would be factors in altering HRR in HF patients. In this prospective, randomized, controlled and 3 group parallel study, 41 stable HF patients were randomly assigned to 3-times-weekly training sessions for 12 weeks, consisting of i) 30 minutes of interval training (IT) (n=17, 63.7±8.8 years old) versus ii) 30 minutes of continuous training (CT) (n=13, 59.6±6.8 years old) versus iii) no training (CON) (n=11, 60.6±9.9 years old). Each patient had cardiopulmonary exercise testing before and after the training program. Maximum heart rates attained during the test and heart rates at 1 and 2 min (HRR1 and HRR2) during the recovery phase were recorded. Paired samples t-test or Wilcoxon signed-rank test was used for comparisons before and after training. One-way ANOVA or Kruskal-Wallis variance analysis was used for comparisons among groups. HRR1 was unchanged after training. HRR2 improved in the IT group after training, and post-training HRR2 values were significantly faster in the IT group than in controls. Both HRR1 and HRR2 was significantly faster, irrespective of exercise protocol in patients with abnormal baseline values after training. HRR1 did not improve after training. HRR2 improved only in the IT group. Both HRRs in patients with abnormal baseline values improved after both exercise protocols. IT might be superior to CT in improving HRR2. Baseline HRR might play a role in its response to exercise.
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Randomised controlled trial of intrapartum fetal heart rate monitoring.
Mahomed, K.; Nyoni, R.; Mulambo, T.; Kasule, J.; Jacobus, E.
1994-01-01
OBJECTIVE--To compare effectiveness of different methods of monitoring intrapartum fetal heart rate. DESIGN--Prospective randomised controlled trial. SETTING--Referral maternity hospital, Harare, Zimbabwe. SUBJECTS--1255 women who were 37 weeks or more pregnant with singleton cephalic presentation and normal fetal heart rate before entry into study. INTERVENTIONS--Intermittent monitoring of fetal heart rate by electronic monitoring, Doppler ultrasound, use of Pinard stethoscope by a research midwife, or routine use of Pinard stethoscope by attending midwife. MAIN OUTCOME MEASURES--Abnormal fetal heart rate patterns, need for operative delivery for fetal distress, neonatal mortality, Apgar scores, admission to neonatal unit, neonatal seizures, and hypoxic ischaemic encephalopathy. RESULTS--Abnormalities in fetal heart rate were detected in 54% (172/318) of the electronic monitoring group, 32% (100/312) of the ultrasonography group, 15% (47/310) of the Pinard stethoscope group, and 9% (28/315) of the routine monitoring group. Caesarean sections were performed for 28% (89%), 24% (76), 10% (32), and 15% (46) of the four groups respectively. Neonatal outcome was best in the ultrasonography group: hypoxic ischaemic encephalopathy occurred in two, one, seven, and 10 cases in the four groups respectively; neonatal seizures occurred only in the last two groups (six and nine cases respectively); and deaths occurred in eight, two, five, and nine cases respectively. CONCLUSIONS--Abnormalities in fetal heart rate were more reliably detected by Doppler ultrasonography than with Pinard stethoscope, and its use resulted in good perinatal outcome. The use of relatively cheap ultrasound monitors should be further evaluated and promoted in obstetric units caring for high risk pregnancies in developing countries with scarce resources. PMID:8136665
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Cook, Rosalind F; Bussey, Carol T; Mellor, Kimberley M; Cragg, Patricia A; Lamberts, Regis R
2017-08-01
What is the central question of the study? The sympathetic system regulates heart rate via β-adrenoceptors; this is impaired during diabetes. However, the specific β-adrenoceptor subtype contributions in heart rate regulation in diabetes in vivo are unknown. What is the main finding and its importance? Telemetric recordings in conscious non-diabetic and type 2 diabetic rats demonstrated that the β 1 -adrenoceptor subtype, and not the β 2 -adrenoceptor, regulated the lower resting heart rate and increased β-adrenoceptor responsiveness in diabetes in vivo. This provides new physiological insight into the dysregulation of heart rate in type 2 diabetes, which is important for improving therapeutic strategies targeting the diabetic chronotropic incompetence. β-Adrenoceptor blockers are widely used to reduce heart rate, the strongest predictor of mortality in cardiac patients, but are less effective in diabetic patients. This study aimed to determine the specific contributions of β 1 - and β 2 -adrenoceptor subtypes to chronotropic responses in type 2 diabetes in vivo, which are currently unknown. Type 2 diabetic and non-diabetic rats were implanted with radiotelemeters to measure arterial blood pressure and derive heart rate in conscious conditions. Vascular access ports were implanted to inject isoprenaline (β 1 - and β 2 -adrenoceptor agonist, 0.1-300 μg kg -1 ) in the presence of atenolol (β 1 -adrenoceptor antagonist, 2000 μg kg -1 ) or nadolol (β 1 - and β 2 -adrenoceptor agonist, 4000 μg kg -1 ) to determine the chronotropic contributions of the β-adrenoceptor subtypes. Resting heart rate was reduced in diabetic rats (388 ± 62 versus 290 ± 37 beats min -1 non-diabetic versus diabetic, P < 0.05, mean ± SD), which remained after atenolol or nadolol administration. Overall β-adrenoceptor chronotropic responsiveness was increased in diabetic rats (change in heart rate at highest dose of isoprenaline: 135 ± 66 versus 205 ± 28
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Probability of detection of clinical seizures using heart rate changes.
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 (p<0.001) shaped by patients' age and gender, seizure class, and years with epilepsy. The probability 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.
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Association between resting heart rate and arterial stiffness in Korean adults.
Park, Byoung-Jin; Lee, Hye-Ree; Shim, Jae-Yong; Lee, Jung-Hyun; Jung, Dong-Hyuk; Lee, Yong-Jae
2010-04-01
Higher resting heart rate, a simple and useful indicator of autonomic balance and metabolic rate, has emerged as an independent predictor for atherosclerotic cardiovascular disease. To determine the association between resting heart rate and arterial stiffness measured by brachial-ankle pulse wave velocity (baPWV). We examined the association between resting heart rate and baPWV in 641 Korean adults (366 men, 275 women) in a health examination program. A high baPWV was defined as greater than 1450 cm/s (>75th percentile). The odds ratios for high baPWVs were calculated using multivariable logistic regression analysis after adjusting for confounding variables across heart rate quartiles (Q1
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Maternal exercise, season and sex modify the daily fetal heart rate rhythm.
Sletten, J; Cornelissen, G; Assmus, J; Kiserud, T; Albrechtsen, S; Kessler, J
2018-05-13
The knowledge on biological rhythms is rapidly expanding. We aimed to define the longitudinal development of the daily (24-hour) fetal heart rate rhythm in an unrestricted, out-of-hospital setting and to examine the effects of maternal physical activity, season and fetal sex. We recruited 48 women with low-risk singleton pregnancies. Using a portable monitor for continuous fetal electrocardiography, fetal heart rate recordings were obtained around gestational weeks 24, 28, 32 and 36. Daily rhythms in fetal heart rate and fetal heart rate variation were detected by cosinor analysis; developmental trends were calculated by population-mean cosinor and multilevel analysis. For the fetal heart rate and fetal heart rate variation, a significant daily rhythm was present in 122/123 (99.2%) and 116/121 (95.9%) of the individual recordings respectively. The rhythms were best described by combining cosine waves with periods of 24 and 8 hours. With increasing gestational age, the magnitude of the fetal heart rate rhythm increased, and the peak of the fetal heart rate variation rhythm shifted from a mean of 14:25 (24 weeks) to 20:52 (36 weeks). With advancing gestation, the rhythm-adjusted mean value of the fetal heart rate decreased linearly in females (P < .001) and nonlinearly in males (quadratic function, P = .001). At 32 and 36 weeks, interindividual rhythm diversity was found in male fetuses during higher maternal physical activity and during the summer season. The dynamic development of the daily fetal heart rate rhythm during the second half of pregnancy is modified by fetal sex, maternal physical activity and season. © 2018 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.
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Modulations of Heart Rate, ECG, and Cardio-Respiratory Coupling Observed in Polysomnography
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). PMID:27826247
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Modulations of Heart Rate, ECG, and Cardio-Respiratory Coupling Observed in Polysomnography.
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).
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The effect of respiratory oscillations in heart rate on detrended fluctuation analysis
NASA Astrophysics Data System (ADS)
Govindan, Rathinaswamy B.; Kota, Srinivas; Al-Shargabi, Tareq; Swisher, Christopher B.; du Plessis, Adre
2017-10-01
Characterization of heart rate using detrended fluctuation analysis (DFA) is impeded by respiratory oscillations. In particular, the short-term exponent measured from 15 to 30 beats is compromised in the DFA. We reconstruct respiratory signal from electrocardiograms and attenuate the respiratory oscillation in the heart rate using a frequency-dependent subtraction approach. We validate this method by applying it to an electrocardiogram signal simulated using a coupled differential equation with the respiratory oscillation modelled using a sine function. The exponent estimated using the proposed approach agreed with the exponent incorporated in the model within a narrow range. In contrast, the exponent obtained from the raw data deviated from the expected value. Furthermore, the exponents obtained for the raw heart rate are smaller than the exponents obtained for the respiration oscillation attenuated heart rate. We apply this approach to heart rate measured from 12 preterm infants that were being treated for prematurity related complications. As observed in the simulated data, we show that compared to the raw heart rate, the respiratory oscillation attenuated heart rate shows higher short-term exponent (p < 0.001).
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Heart rate variability in newborns.
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.
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Waninge, Aly; van der Putten, Annette A J; Stewart, Roy E; Steenbergen, Bert; van Wijck, Ruud; van der Schans, Cees P
2013-11-01
Because physical fitness and health are related to physical activity, it is important to gain an insight into the physical activity levels of persons with profound intellectual and multiple disabilities (PIMD). The purpose of this study was to examine heart rate patterns to measure the activity levels of persons with PIMD and to analyze these heart rate patterns according to participant characteristics, observed level of activity, days, and time of day. The heart rate patterns of 24 participants with PIMD were measured continuously using a heart rate monitor for 8 h · d for a period of 6 days. Physical activity levels were measured with questionnaires. Data were analyzed using multilevel analysis. The results indicate that the participants use only 32% of their heart rate reserve over 6 days. The intensity of heart rate reserve ranged from 1 to 62%. On a given day, wide ranges in heart rates between participants and within persons were observed. Between days, only small ranges in the heart rate were found. The participants could be grouped into 4 classes according to their heart rate. In addition, factors such as time of day, physical activity, and age are significantly related to heart rate patterns. In conclusion, this study is an important first step in exploring activity patterns based on heart rate patterns in persons with PIMD. The participants used relatively small fractions of their heart rate reserves. Time of day and age appear to have a considerable influence on heart rate patterns. The observed classes in heart rate patterns suggest that other probably more personal and psychosocial factors have significant influences on heart rate patterns, as well.
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Quantification of fetal heart rate regularity using symbolic dynamics
NASA Astrophysics Data System (ADS)
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
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Introducing a novel mechanism to control heart rate in the ancestral Pacific hagfish.
Wilson, Christopher M; Roa, Jinae N; Cox, Georgina K; Tresguerres, Martin; Farrell, Anthony P
2016-10-15
Although neural modulation of heart rate is well established among chordate animals, the Pacific hagfish (Eptatretus stoutii) lacks any cardiac innervation, yet it can increase its heart rate from the steady, depressed heart rate seen in prolonged anoxia to almost double its normal normoxic heart rate, an almost fourfold overall change during the 1-h recovery from anoxia. The present study sought mechanistic explanations for these regulatory changes in heart rate. We provide evidence for a bicarbonate-activated, soluble adenylyl cyclase (sAC)-dependent mechanism to control heart rate, a mechanism never previously implicated in chordate cardiac control. © 2016. Published by The Company of Biologists Ltd.
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Diminution of Heart Rate Variability in Bipolar Depression
Hage, Brandon; Britton, Briana; Daniels, David; Heilman, Keri; Porges, Stephen W.; Halaris, Angelos
2017-01-01
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. PMID:29270399
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Power spectral analysis of heart rate in hyperthyroidism.
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 < 0.01); standing, 6.0 +/- 2.7 vs. 15.0 +/- 4.0 NU (P < 0.01); mean +/- SEM]. On the other hand components were comparable in the 2 groups (lying, 64.0 +/- 6.9 vs. 62.0 +/- 6.5 NU; standing, 77.0 +/- 6.5 vs. 78.0 +/- 5.4 NU). Hence, the LF/HF ratio, which is considered an index of sympathovagal balance, was increased in hyperthyroid subjects while both lying (11.3 +/- 4.5 vs. 3.5 +/- 1.1; P < 0.05) and standing (54.0 +/- 12.6 vs. 9.8 +/- 2.6; P < 0.02). This parameter was positively correlated with both T3 (r = 0.61; P < 0.05) and free T4 (r = 0.63; P < 0.05) serum levels. Among traditional cardiovascular autonomic tests, the reflex response of heart rate during lying to standing was significantly lower in hyperthyroid patients than in controls (1
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Effect of uterine contractions on fetal heart rate in pregnancy: a prospective observational study.
Sletten, Julie; Kiserud, Torvid; Kessler, Jörg
2016-10-01
The new Holter monitoring technology enables long-term electrocardiographic recording of the fetal heart rate without discomfort for the mother. The aim of the study was to assess the feasibility of a fetal Holter monitor. This technology was further used to study fetal heart rate outside the hospital setting during normal daily activities and to test the hypothesis that uterine activity during pregnancy influences fetal heart rate. Prospective observational study including 12 healthy pregnant women at 20-40 weeks of gestation. Data were collected using the Monica AN24 system. Outcome measures were fetal heart rate, maternal heart rate, and uterine activity categorized according to the strength of the electrohysterographic signal. The recordings had a median length of 18.8 h, and fetal heart rate and maternal heart rate were obtained with success rates of 73.1 and 99.9%, respectively. Uterine activity was found to affect fetal heart rate in all participants. Compared with the basal tone and mild levels of uterine activity, moderate and strong levels of uterine activity were associated with increases in fetal heart rate of 4.0 and 5.7 beats/min, respectively. At night, the corresponding increases were 4.9 and 7.6 beats/min. Linear correlations were found between maternal heart rate and fetal heart rate in 11 of the 12 cases, with a mean coefficient beta of 0.189. Both maternal heart rate and fetal heart rate exhibited a diurnal pattern, with lower heart rates being recorded at night. Uterine activity during pregnancy is associated with a graded response in fetal heart rate and may represent a physiological challenge for the development and adaptation of the fetal cardiovascular system. © 2016 Nordic Federation of Societies of Obstetrics and Gynecology.
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Evaluation of Dry Electrodes in Canine Heart Rate Monitoring.
Virtanen, Juhani; Somppi, Sanni; Törnqvist, Heini; Jeyhani, Vala; Fiedler, Patrique; Gizatdinova, Yulia; Majaranta, Päivi; Väätäjä, Heli; Valldeoriola Cardó, Anna; Lekkala, Jukka; Tuukkanen, Sampo; Surakka, Veikko; Vainio, Outi; Vehkaoja, Antti
2018-05-30
The functionality of three dry electrocardiogram electrode constructions was evaluated by measuring canine heart rate during four different behaviors: Standing, sitting, lying and walking. The testing was repeated (n = 9) in each of the 36 scenarios with three dogs. Two of the electrodes were constructed with spring-loaded test pins while the third electrode was a molded polymer electrode with Ag/AgCl coating. During the measurement, a specifically designed harness was used to attach the electrodes to the dogs. The performance of the electrodes was evaluated and compared in terms of heartbeat detection coverage. The effect on the respective heart rate coverage was studied by computing the heart rate coverage from the measured electrocardiogram signal using a pattern-matching algorithm to extract the R-peaks and further the beat-to-beat heart rate. The results show that the overall coverage ratios regarding the electrodes varied between 45⁻95% in four different activity modes. The lowest coverage was for lying and walking and the highest was for standing and sitting.
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Poliwczak, A R; Waszczykowska, E; Dziankowska-Bartkowiak, B; Koziróg, M; Dworniak, K
2018-03-01
Background Systemic lupus erythematosus is a progressive autoimmune disease. There are reports suggesting that patients even without overt signs of cardiovascular complications have impaired autonomic function. The aim of this study was to assess autonomic function using heart rate turbulence and heart rate variability parameters indicated in 24-hour ECG Holter monitoring. Methods Twenty-six women with systemic lupus erythematosus and 30 healthy women were included. Twenty-four hour ambulatory ECG-Holter was performed in home conditions. The basic parameters of heart rate turbulence and heart rate variability were calculated. The analyses were performed for the entire day and separately for daytime activity and night time rest. Results There were no statistically significant differences in the basic anthropometric parameters. The mean duration of disease was 11.52 ± 7.42. There was a statistically significant higher turbulence onset (To) value in patients with systemic lupus erythematosus, median To = -0.17% (minimum -1.47, maximum 3.0) versus To = -1.36% (minimum -4.53, maximum -0.41), P < 0.001. There were no such differences for turbulence slope (Ts). In the 24-hour analysis almost all heart rate variability parameters were significantly lower in the systemic lupus erythematosus group than in the healthy controls, including SDANN and r-MSSD and p50NN. Concerning the morning activity and night resting periods, the results were similar as for the whole day. In the control group, higher values in morning activity were noted for parameters that characterise sympathetic activity, especially SDANN, and were significantly lower for parasympathetic parameters, including r-MSSD and p50NN, which prevailed at night. There were no statistically significant changes for systemic lupus erythematosus patients for p50NN and low and very low frequency. There was a positive correlation between disease duration and SDNN, R = 0.417; P < 0.05 and SDANN, R
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Addison, Paul S; Jacquel, Dominique; Foo, David M H; Borg, Ulf R
2017-11-09
The robust monitoring of heart rate from the video-photoplethysmogram (video-PPG) during challenging conditions requires new analysis techniques. The work reported here extends current research in this area by applying a motion tolerant algorithm to extract high quality video-PPGs from a cohort of subjects undergoing marked heart rate changes during a hypoxic challenge, and exhibiting a full range of skin pigmentation types. High uptimes in reported video-based heart rate (HR vid ) were targeted, while retaining high accuracy in the results. Ten healthy volunteers were studied during a double desaturation hypoxic challenge. Video-PPGs were generated from the acquired video image stream and processed to generate heart rate. HR vid was compared to the pulse rate posted by a reference pulse oximeter device (HR p ). Agreement between video-based heart rate and that provided by the pulse oximeter was as follows: Bias = - 0.21 bpm, RMSD = 2.15 bpm, least squares fit gradient = 1.00 (Pearson R = 0.99, p < 0.0001), with a 98.78% reporting uptime. The difference between the HR vid and HR p exceeded 5 and 10 bpm, for 3.59 and 0.35% of the reporting time respectively, and at no point did these differences exceed 25 bpm. Excellent agreement was found between the HR vid and HR p in a study covering the whole range of skin pigmentation types (Fitzpatrick scales I-VI), using standard room lighting and with moderate subject motion. Although promising, further work should include a larger cohort with multiple subjects per Fitzpatrick class combined with a more rigorous motion and lighting protocol.
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Heart-Rate Recovery Index Is Impaired in Behçet's Disease
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
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Leptin decreases heart rate associated with increased ventricular repolarization via its receptor.
Lin, Yen-Chang; Huang, Jianying; Hileman, Stan; Martin, Karen H; Hull, Robert; Davis, Mary; Yu, Han-Gang
2015-11-15
Leptin has been proposed to modulate cardiac electrical properties via β-adrenergic receptor activation. The presence of leptin receptors and adipocytes in myocardium raised a question as to whether leptin can directly modulate cardiac electrical properties such as heart rate and QT interval via its receptor. In this work, the role of local direct actions of leptin on heart rate and ventricular repolarization was investigated. We identified the protein expression of leptin receptors at cell surface of sinus node, atrial, and ventricular myocytes isolated from rat heart. Leptin at low doses (0.1-30 μg/kg) decreased resting heart rate; at high doses (150-300 μg/kg), leptin induced a biphasic effect (decrease and then increase) on heart rate. In the presence of high-dose propranolol (30 mg/kg), high-dose leptin only reduced heart rate and sometimes caused sinus pauses and ventricular tachycardia. The leptin-induced inhibition of resting heart rate was fully reversed by leptin antagonist. Leptin also increased heart rate-corrected QT interval (QTc), and leptin antagonist did not. In isolated ventricular myocytes, leptin (0.03-0.3 μg/ml) reversibly increased the action potential duration. These results supported our hypothesis that in addition to indirect pathway via sympathetic tone, leptin can directly decrease heart rate and increase QT interval via its receptor independent of β-adrenergic receptor stimulation. During inhibition of β-adrenergic receptor activity, high concentration of leptin in myocardium can cause deep bradycardia, prolonged QT interval, and ventricular arrhythmias. Copyright © 2015 the American Physiological Society.
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Leptin decreases heart rate associated with increased ventricular repolarization via its receptor
Lin, Yen-Chang; Huang, Jianying; Hileman, Stan; Martin, Karen H.; Hull, Robert; Davis, Mary
2015-01-01
Leptin has been proposed to modulate cardiac electrical properties via β-adrenergic receptor activation. The presence of leptin receptors and adipocytes in myocardium raised a question as to whether leptin can directly modulate cardiac electrical properties such as heart rate and QT interval via its receptor. In this work, the role of local direct actions of leptin on heart rate and ventricular repolarization was investigated. We identified the protein expression of leptin receptors at cell surface of sinus node, atrial, and ventricular myocytes isolated from rat heart. Leptin at low doses (0.1–30 μg/kg) decreased resting heart rate; at high doses (150–300 μg/kg), leptin induced a biphasic effect (decrease and then increase) on heart rate. In the presence of high-dose propranolol (30 mg/kg), high-dose leptin only reduced heart rate and sometimes caused sinus pauses and ventricular tachycardia. The leptin-induced inhibition of resting heart rate was fully reversed by leptin antagonist. Leptin also increased heart rate-corrected QT interval (QTc), and leptin antagonist did not. In isolated ventricular myocytes, leptin (0.03–0.3 μg/ml) reversibly increased the action potential duration. These results supported our hypothesis that in addition to indirect pathway via sympathetic tone, leptin can directly decrease heart rate and increase QT interval via its receptor independent of β-adrenergic receptor stimulation. During inhibition of β-adrenergic receptor activity, high concentration of leptin in myocardium can cause deep bradycardia, prolonged QT interval, and ventricular arrhythmias. PMID:26408544
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Borer, Jeffrey S; Deedwania, Prakash C; Kim, Jae B; Böhm, Michael
2016-12-15
Heart rate (HR) is a risk factor in patients with chronic systolic heart failure (HF) that, when reduced, provides outcome benefits. It is also a target for angina pectoris prevention and a risk marker in chronic coronary artery disease without HF. HR can be reduced by drugs; however, among those used clinically, only ivabradine reduces HR directly in the sinoatrial nodal cells without other known effects on the cardiovascular system. This review provides current information regarding the safety and efficacy of HR reduction with ivabradine in clinical studies involving >36,000 patients with chronic stable coronary artery disease and >6,500 patients with systolic HF. The largest trials, Morbidity-Mortality Evaluation of the I f Inhibitor Ivabradine in Patients With Coronary Disease and Left Ventricular Dysfunction and Study Assessing the Morbidity-Mortality Benefits of the I f Inhibitor Ivabradine in Patients With Coronary Artery Disease, showed no effect on outcomes. The Systolic Heart Failure Treatment With the I f Inhibitor Ivabradine Trial, a randomized controlled trial in >6,500 patients with HF, revealed marked and significant HR-mediated reduction in cardiovascular mortality or HF hospitalizations while improving quality of life and left ventricular mechanical function after treatment with ivabradine. The adverse effects of ivabradine predominantly included bradycardia and atrial fibrillation (both uncommon) and ocular flashing scotomata (phosphenes) but otherwise were similar to placebo. In conclusion, ivabradine improves outcomes in patients with systolic HF; rates of overall adverse events are similar to placebo. Copyright © 2016 Elsevier Inc. All rights reserved.
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Böhm, Michael; Borer, Jeffrey; Ford, Ian; Gonzalez-Juanatey, Jose R; Komajda, Michel; Lopez-Sendon, Jose; Reil, Jan-Christian; Swedberg, Karl; Tavazzi, Luigi
2013-01-01
We analysed the effect of ivabradine on outcomes in heart failure (HF) patients on recommended background therapies with heart rates ≥75 bpm and <75 bpm in the SHIFT trial. A cut-off value of ≥75 bpm was chosen by the EMEA for approval for the use of ivabradine in chronic heart failure. The SHIFT population was divided by baseline heart rate ≥75 or <75 bpm. The effect of ivabradine was analysed for primary composite endpoint (cardiovascular death or HF hospitalization) and other endpoints. In the ≥75 bpm group, ivabradine reduced primary endpoint (HR 0.76, 95 % CI 0.68-0.85, P < 0.0001), all-cause mortality (HR 0.83, 95 % CI, 0.72-0.96, P = 0.0109), cardiovascular mortality (HR 0.83, 95 % CI, (0.71-0.97, P = 0.0166), HF death (HR 0.61, 95 % CI, 0.46-0.81, P < 0.0006), and HF hospitalization (HR 0.70, 95 % CI, 0.61-0.80, P < 0.0001). Risk reduction depended on heart rate after 28 days, with the best protection for heart rates <60 bpm or reductions >10 bpm. None of the endpoints was significantly reduced in the <75 bpm group, though there were trends for risk reductions in HF death and hospitalization for heart rate <60 bpm and reductions >10 bpm. Ivabradine was tolerated similarly in both groups. The effect of ivabradine on outcomes is greater in patients with heart rate ≥75 bpm with heart rates achieved <60 bpm or heart rate reductions >10 bpm predicting best risk reduction. Our findings emphasize the importance of identification of high-risk HF patients by high heart rates and their treatment with heart rate-lowering drugs such as ivabradine.
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MicroRNA and receptor mediated signaling pathways as potential therapeutic targets in heart failure.
Tuttolomondo, Antonino; Simonetta, Irene; Pinto, Antonio
2016-11-01
Cardiac remodelling is a complex pathogenetic pathway involving genome expression, molecular, cellular, and interstitial changes that cause changes in size, shape and function of the heart after cardiac injury. Areas covered: We will review recent advances in understanding the role of several receptor-mediated signaling pathways and micro-RNAs, in addition to their potential as candidate target pathways in the pathogenesis of heart failure. The myocyte is the main target cell involved in the remodelling process via ischemia, cell necrosis and apoptosis (by means of various receptor pathways), and other mechanisms mediated by micro-RNAs. We will analyze the role of some receptor mediated signaling pathways such as natriuretic peptides, mediators of glycogen synthase kinase 3 and ERK1/2 pathways, beta-adrenergic receptor subtypes and relaxin receptor signaling mechanisms, TNF/TNF receptor family and TWEAK/Fn14 axis, and some micro-RNAs as candidate target pathways in pathogenesis of heart failure. These mediators of receptor-mediated pathways and micro-RNA are the most addressed targets of emerging therapies in modern heart failure treatment strategies. Expert opinion: Future treatment strategies should address mediators involved in multiple steps within heart failure pathogenetic pathways.
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Opportunity for information search and the effect of false heart rate feedback.
Barefoot, John C; Straub, Ronald B
2005-01-01
The role of information search in the attribution of physiological states was investigated by manipulating the subject's opportunity for information search following the presentation of false information about his heart-rate reactions to photographs of female nudes. Consistent with the self-persuasion hypothesis proposed by Valins, the rated attractiveness of the slides was not affected by the false heart-rate feedback for those subjects who were prevented from visually searching the slides. Those subjects who had ample opportunity to view the slides rated those slides accompanied by false information of a heart-rate change as more attractive than those slides which were not paired with a change in heart rate.
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Heart rate measurement as a tool to quantify sedentary behavior.
Åkerberg, Anna; Koshmak, Gregory; Johansson, Anders; Lindén, Maria
2015-01-01
Sedentary work is very common today. The aim of this pilot study was to attempt to differentiate between typical work situations and to investigate the possibility to break sedentary behavior, based on physiological measurement among office workers. Ten test persons used one heart rate based activity monitor (Linkura), one pulse oximeter device (Wrist) and one movement based activity wristband (Fitbit Flex), in different working situations. The results showed that both heart rate devices, Linkura and Wrist, were able to detect differences in heart rate between the different working situations (resting, sitting, standing, slow walk and medium fast walk). The movement based device, Fitbit Flex, was only able to separate differences in steps between slow walk and medium fast walk. It can be concluded that heart rate measurement is a promising tool for quantifying and separating different working situations, such as sitting, standing and walking.
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Comparison of heart rate variability and pulse rate variability detected with photoplethysmography
NASA Astrophysics Data System (ADS)
Rauh, Robert; Limley, Robert; Bauer, Rainer-Dieter; Radespiel-Troger, Martin; Mueck-Weymann, Michael
2004-08-01
This study compares ear photoplethysmography (PPG) and electrocardiogram (ECG) in providing accurate heart beat intervals for use in calculations of heart rate variability (HRV, from ECG) or of pulse rate variability (PRV, from PPG) respectively. Simultaneous measurements were taken from 44 healthy subjects at rest during spontaneous breathing and during forced metronomic breathing (6/min). Under both conditions, highly significant (p > 0.001) correlations (1.0 > r > 0.97) were found between all evaluated common HRV and PRV parameters. However, under both conditions the PRV parameters were higher than HRV. In addition, we calculated the limits of agreement according to Bland and Altman between both techniques and found good agreement (< 10% difference) for heart rate and standard deviation of normal-to-normal intervals (SDNN), but only moderate (10-20%) or even insufficient (> 20%) agreement for other standard HRV and PRV parameters. Thus, PRV data seem to be acceptable for screening purposes but, at least at this state of knowledge, not for medical decision making. However, further studies are needed before more certain determination can be made.
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[The influence of physical exercise on heart rate variability].
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
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Shang, Xiaoke; Lu, Rong; Liu, Mei; Xiao, Shuna; Dong, Nianguo
2017-10-01
Although elevated resting heart rate is related to poor outcomes in heart failure (HF) with reduced ejection fraction, the association in HF with preserved ejection fraction (HFpEF) remains inconclusive. Therefore, we conducted a dose-response meta-analysis to examine the prognostic role of heart rate in patients with HFpEF.We searched PubMed and Embase databases until April 2017 and manually reviewed the reference lists of relevant literatures. Random effect models were used to pool the study-specific hazard ratio (HR) of outcomes, including all-cause death, cardiovascular death, and HF hospitalization.Six studies with 7 reports were finally included, totaling 14,054 patients with HFpEF. The summary HR (95% confidence interval [CI]) for every 10 beats/minute increment in heart rate was 1.04 (1.02-1.06) for all-cause death, 1.06 (1.02-1.10) for cardiovascular death, and 1.05 (1.01-1.08) for HF hospitalization. Subgroup analyses indicated that these positive relationships were significant in patients with sinus rhythm but not in those with atrial fibrillation. There was also evidence for nonlinear relationship of heart rate with each of the outcomes (All P for nonlinearity < .05).Higher heart rate in sinus rhythm is a risk factor for adverse outcomes in patients with HFpEF. Future trials are required to determine whether heart rate reduction may improve the prognosis of HFpEF.
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Can heart rate predict blood pressure response to anti-hypertensive drug therapy?
Owens, P E; Lyons, S; O'Brien, E
1998-04-01
The use of heart rate in clinical practice is limited by its variability under measurement situations. The mean heart rate on ambulatory monitoring provides a more robust statistic for clinical use. We examined the relationship between mean heart rate on initial referral ambulatory blood pressure monitoring (ABPM) to the BP-lowering efficacy of the four main groups of anti-hypertensive medications, in a referral hypertensive population. Patients were retrospectively identified by review of the BP database, and data collected from the initial referral BP monitor off medication, and the subsequent ABPM after treatment with either beta-blockers, diuretics, calcium antagonists or angiotensin-converting enzyme (ACE) inhibitors. The change in mean arterial BP from the initial to the subsequent ABPM (ie, as a result of treatment) was correlated with the mean heart rate on the initial ABPM. A moderate association was found for initial daytime heart rate and BP response to beta-blockers (r = 0.24, P = 0.02), and ACE inhibitors (r = 0.14, P = 0.05). No such association was found for calcium antagonists or diuretics. When the groups were divided into those with a mean daytime heart rate <75 and > or =75 beats per min, BP reduction from beta-blocker and ACE inhibitor therapy was significantly greater in those patients with a higher daytime heart rate. We conclude that average daytime heart rate on pre-treatment ABPM can be useful as a predictor of BP response to beta-blockade or ACE inhibition.
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Voluntary control of breathing does not alter vagal modulation of heart rate
NASA Technical Reports Server (NTRS)
Patwardhan, A. R.; Evans, J. M.; Bruce, E. N.; Eckberg, D. L.; Knapp, C. F.
1995-01-01
Variations in respiratory pattern influence the heart rate spectrum. It has been suggested, hence, that metronomic respiration should be used to correctly assess vagal modulation of heart rate by using spectral analysis. On the other hand, breathing to a metronome has been reported to increase heart rate spectral power in the high- or respiratory frequency region; this finding has led to the suggestion that metronomic respiration enhances vagal tone or alters vagal modulation of heart rate. To investigate whether metronomic breathing complicates the interpretation of heart rate spectra by altering vagal modulation, we recorded the electrocardiogram and respiration from eight volunteers during three breathing trials of 10 min each: 1) spontaneous breathing (mean rate of 14.4 breaths/min); 2) breathing to a metronome at the rate of 15, 18, and 21 breaths/min for 2, 6, and 2 min, respectively; and 3) breathing to a metronome at the rate of 18 breaths/min for 10 min. Data were also collected from eight volunteers who breathed spontaneously for 20 min and breathed metronomically at each subject's mean spontaneous breathing frequency for 20 min. Results from the three 10-min breathing trials showed that heart rate power in the respiratory frequency region was smaller during metronomic breathing than during spontaneous breathing. This decrease could be explained fully by the higher breathing frequencies used during trials 2 and 3 of metronomic breathing. When the subjects breathed metronomically at each subject's mean breathing frequency, the heart rate powers during metronomic breathing were similar to those during spontaneous breathing. Our results suggest that vagal modulation of heart rate is not altered and vagal tone is not enhanced during metronomic breathing.
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Ozcelik, O; Kelestimur, H
2004-01-01
Anaerobic threshold which describes the onset of systematic increase in blood lactate concentration is a widely used concept in clinical and sports medicine. A deflection point between heart rate-work rate has been introduced to determine the anaerobic threshold non-invasively. However, some researchers have consistently reported a heart rate deflection at higher work rates, while others have not. The present study was designed to investigate whether the heart rate deflection point accurately predicts the anaerobic threshold under the condition of acute hypoxia. Eight untrained males performed two incremental exercise tests using an electromagnetically braked cycle ergometer: one breathing room air and one breathing 12 % O2. The anaerobic threshold was estimated using the V-slope method and determined from the increase in blood lactate and the decrease in standard bicarbonate concentration. This threshold was also estimated by in the heart rate-work rate relationship. Not all subjects exhibited a heart rate deflection. Only two subjects in the control and four subjects in the hypoxia groups showed a heart rate deflection. Additionally, the heart rate deflection point overestimated the anaerobic threshold. In conclusion, the heart rate deflection point was not an accurate predictor of anaerobic threshold and acute hypoxia did not systematically affect the heart rate-work rate relationships.
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AUTONOMIC CONTROL OF HEART RATE AFTER EXERCISE IN TRAINED WRESTLERS
Báez, San Martín E.; Von Oetinger, A.; Cañas, Jamett R.; Ramírez, Campillo R.
2013-01-01
The objective of this study was to establish differences in vagal reactivation, through heart rate recovery and heart rate variability post exercise, in Brazilian jiu-jitsu wrestlers (BJJW). A total of 18 male athletes were evaluated, ten highly trained (HT) and eight moderately trained (MT), who performed a maximum incremental test. At the end of the exercise, the R-R intervals were recorded during the first minute of recovery. We calculated heart rate recovery (HRR60s), and performed linear and non-linear (standard deviation of instantaneous beat-to-beat R-R interval variability – SD1) analysis of heart rate variability (HRV), using the tachogram of the first minute of recovery divided into four segments of 15 s each (0-15 s, 15-30 s, 30-45 s, 45-60 s). Between HT and MT individuals, there were statistically significant differences in HRR60s (p <0.05) and in the non linear analysis of HRV from SD130-45s (p <0.05) and SD145-60s (p <0.05). The results of this research suggest that heart rate kinetics during the first minute after exercise are related to training level and can be used as an index for autonomic cardiovascular control in BJJW. PMID:24744476
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Autonomic control of heart rate after exercise in trained wrestlers.
Henríquez, Olguín C; Báez, San Martín E; Von Oetinger, A; Cañas, Jamett R; Ramírez, Campillo R
2013-06-01
The objective of this study was to establish differences in vagal reactivation, through heart rate recovery and heart rate variability post exercise, in Brazilian jiu-jitsu wrestlers (BJJW). A total of 18 male athletes were evaluated, ten highly trained (HT) and eight moderately trained (MT), who performed a maximum incremental test. At the end of the exercise, the R-R intervals were recorded during the first minute of recovery. We calculated heart rate recovery (HRR60s), and performed linear and non-linear (standard deviation of instantaneous beat-to-beat R-R interval variability - SD1) analysis of heart rate variability (HRV), using the tachogram of the first minute of recovery divided into four segments of 15 s each (0-15 s, 15-30 s, 30-45 s, 45-60 s). Between HT and MT individuals, there were statistically significant differences in HRR60s (p <0.05) and in the non linear analysis of HRV from SD130-45s (p <0.05) and SD145-60s (p <0.05). The results of this research suggest that heart rate kinetics during the first minute after exercise are related to training level and can be used as an index for autonomic cardiovascular control in BJJW.
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Sensor fusion methods for reducing false alarms in heart rate monitoring.
Borges, Gabriel; Brusamarello, Valner
2016-12-01
Automatic patient monitoring is an essential resource in hospitals for good health care management. While alarms caused by abnormal physiological conditions are important for the delivery of fast treatment, they can be also a source of unnecessary noise because of false alarms caused by electromagnetic interference or motion artifacts. One significant source of false alarms is related to heart rate, which is triggered when the heart rhythm of the patient is too fast or too slow. In this work, the fusion of different physiological sensors is explored in order to create a robust heart rate estimation. A set of algorithms using heart rate variability index, Bayesian inference, neural networks, fuzzy logic and majority voting is proposed to fuse the information from the electrocardiogram, arterial blood pressure and photoplethysmogram. Three kinds of information are extracted from each source, namely, heart rate variability, the heart rate difference between sensors and the spectral analysis of low and high noise of each sensor. This information is used as input to the algorithms. Twenty recordings selected from the MIMIC database were used to validate the system. The results showed that neural networks fusion had the best false alarm reduction of 92.5 %, while the Bayesian technique had a reduction of 84.3 %, fuzzy logic 80.6 %, majority voter 72.5 % and the heart rate variability index 67.5 %. Therefore, the proposed algorithms showed good performance and could be useful in bedside monitors.
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Perinatal sulfur dioxide exposure alters brainstem parasympathetic control of heart rate.
Woerman, Amanda L; Mendelowitz, David
2013-07-01
Sulfur dioxide (SO₂) is an air pollutant that impedes neonatal development and induces adverse cardiorespiratory health effects, including tachycardia. Here, an animal model was developed that enabled characterization of (i) in vivo alterations in heart rate and (ii) altered activity in brainstem neurons that control heart rate after perinatal SO₂ exposure. Pregnant Sprague-Dawley dams and their pups were exposed to 5 parts per million SO₂ for 1 h daily throughout gestation and 6 days postnatal. Electrocardiograms were recorded from pups at 5 days postnatal to examine changes in basal and diving reflex-evoked changes in heart rate following perinatal SO₂ exposure. In vitro studies employed whole-cell patch-clamp electrophysiology to examine changes in neurotransmission to cardiac vagal neurons within the nucleus ambiguus upon SO₂ exposure using a preparation that maintains fictive inspiratory activity recorded from the hypoglossal rootlet. Perinatal SO₂ exposure increased heart rate and blunted the parasympathetic-mediated diving reflex-evoked changes in heart rate. Neither spontaneous nor inspiratory-related inhibitory GABAergic or glycinergic neurotransmission to cardiac vagal neurons was altered by SO₂ exposure. However, excitatory glutamatergic neurotransmission was decreased by 51.2% upon SO₂ exposure. This diminished excitatory neurotransmission was tetrodotoxin-sensitive, indicating SO₂ exposure impaired the activity of preceding glutamatergic neurons that synapse upon cardiac vagal neurons. Diminished glutamatergic, but unaltered inhibitory neurotransmission to cardiac vagal neurons provides a mechanism for the observed SO₂-induced elevated heart rate via an impairment of brainstem cardioinhibitory parasympathetic activity to the heart.
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Design of heart rate monitor based on piezoelectric sensor using an Arduino
NASA Astrophysics Data System (ADS)
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.
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A comparison of heart rate responses in racquet games.
Docherty, D.
1982-01-01
The present study investigated the heart rate response to playing tennis with special reference to the skill levels and ages of the participants. Data obtained in a similar manner during earlier studies of badminton and squash players were compared with that obtained during tennis. The number of rallies, mean rally time and actual playing time in 30 minutes of play was also compared for the different skill levels and sports. Results showed that playing tennis raised the players' heart rates to 68-70% of their predicted maximum heart rate (PMHR). Playing squash and badminton could raise heart rates to 80-85% of the players' PMHR which was significantly higher than the values obtained for tennis. The actual skill level of the participants within their chosen sport did not have a significant effect in predicting the physical demands of squash or tennis but was important in predicting the heart rate response of badminton players. The more skillful the badminton player the greater the cardiac response as a result of game play. Analysis of time spent in actual play revealed that tennis players were involved in play for only five of the thirty minutes of game play, compared to 15 and 10 min respectively for squash and badminton. Skill level within each sport was only a significant factor in predicting length of play for squash players in which the medium and highly skilled groups played significantly longer than those of a lower level of skill. Images p96-a PMID:7104564
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Effect of suprachiasmatic lesions on diurnal heart rate rhythm in the rat
NASA Technical Reports Server (NTRS)
Saleh, M. A.; Winget, C. M.
1977-01-01
Heart rate and locomotor activity of rats kept under 12L/12D illumination regimen were recorded every six minutes for ten days using implantable radio transmitters. Some of the rats then received bilateral RF lesions into the suprachiasmatic nucleus (SCN). Control sham operations were performed on the rest of the animals. After recovery from surgery, recording of heart rate and locomotor activity was continued for ten days. SCN-lesioned rats showed no significant diurnal fluctuation in heart rate, while normal and sham-operated rats showed the normal diurnal rhythm in that function. The arrhythmic diurnal heart-rate pattern of SCN rats appeared to be correlated with their sporadic activity pattern. The integrity of the suprachiasmatic nucleus is therefore necessary for the generation and/or expression of diurnal rhythmicity in heart rate in the rat.
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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.
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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. PMID:25324790
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An improved method of measuring heart rate using a webcam
NASA Astrophysics Data System (ADS)
Liu, Yi; Ouyang, Jianfei; Yan, Yonggang
2014-09-01
Measuring heart rate traditionally requires special equipment and physical contact with the subject. Reliable non-contact and low-cost measurements are highly desirable for convenient and comfortable physiological self-assessment. Previous work has shown that consumer-grade cameras can provide useful signals for remote heart rate measurements. In this paper a simple and robust method of measuring the heart rate using low-cost webcam is proposed. Blood volume pulse is extracted by proper Region of Interest (ROI) and color channel selection from image sequences of human faces without complex computation. Heart rate is subsequently quantified by spectrum analysis. The method is successfully applied under natural lighting conditions. Results of experiments show that it takes less time, is much simpler, and has similar accuracy to the previously published and widely used method of Independent Component Analysis (ICA). Benefitting from non-contact, convenience, and low-costs, it provides great promise for popularization of home healthcare and can further be applied to biomedical research.
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Hategan, Lidia; Csányi, Beáta; Ördög, Balázs; Kákonyi, Kornél; Tringer, Annamária; Kiss, Orsolya; Orosz, Andrea; Sághy, László; Nagy, István; Hegedűs, Zoltán; Rudas, László; Széll, Márta; Varró, András; Forster, Tamás; Sepp, Róbert
2017-08-15
The most important molecular determinant of heart rate regulation in sino-atrial pacemaker cells includes hyperpolarization-activated, cyclic nucleotide-gated ion channels, the major isoform of which is encoded by the HCN4 gene. Mutations affecting the HCN4 gene are associated primarily with sick sinus syndrome. A novel c.1737+1 G>T 'splice-site' HCN4 mutation was identified in a large family with familial bradycardia which co-segregated with the disease providing a two-point LOD score of 4.87. Twelve out of the 22 investigated family members [4 males, 8 females average age 36 (SD 6) years] were considered as clinically affected (heart rate<60/min on resting ECG). Minimum [36 (SD 7) vs. 47 (SD 5) bpm, p=0.0087) and average heart rates [62 (SD 8) vs. 73 (SD 8) bpm, p=0.0168) were significantly lower in carriers on 24-hour Holter recordings. Under maximum exercise test carriers achieved significantly lower heart rates than non-carrier family members, and percent heart rate reserve and percent corrected heart rate reserve were significantly lower in carriers. Applying rigorous criteria for chronotropic incompetence a higher number of carriers exhibited chronotropic incompetence. Parameters, characterizing short-term variability of heart rate (i.e. rMSSD and pNN50%) were increased in carrier family members, even after normalization for heart rate, in the 24-hour ECG recordings with the same relative increase in 5-minute recordings. The identified novel 'splice site' HCN4 gene mutation, c.1737+1 G>T, causes familial bradycardia and leads to reduced heart rate response, impaired chronotropic competence and increased short-term heart rate variability in the mutation carriers. Copyright © 2017 Elsevier B.V. All rights reserved.
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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.
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Measuring task-related changes in heart rate variability.
Moses, Ziev B; Luecken, Linda J; Eason, James C
2007-01-01
Small beat-to-beat differences in heart rate are the result of dynamic control of the cardiovascular system by the sympathetic and parasympathetic nervous systems. Heart rate variability (HRV) has been positively correlated with both mental and physical health. While many studies measure HRV under rest conditions, few have measured HRV during stressful situations. We describe an experimental protocol designed to measure baseline, task, and recovery values of HRV as a function of three different types of stressors. These stressors involve an attention task, a cold pressor test, and a videotaped speech presentation. We found a measurable change in heart rate in participants (n=10) during each task (all p's < 0.05). The relative increase or decrease from pre-task heart rate was predicted by task (one-way ANOVA, p= 0.0001). Spectral analysis of HRV during the attention task revealed consistently decreased measures of both high (68+/-7%, mean+/-S.E.) and low (62+/-13%) frequency HRV components as compared to baseline. HRV spectra for the cold pressor and speech tasks revealed no consistent patterns of increase or decrease from baseline measurements. We also found no correlation in reactivity measures between any of our tasks. These findings suggest that each of the tasks in our experimental design elicits a different type of stress response in an individual. Our experimental approach may prove useful to biobehavioral researchers searching for factors that determine individual differences in responses to stress in daily life.
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Interdisciplinary Team Huddles for Fetal Heart Rate Tracing Review.
Thompson, Lisa; Krening, Cynthia; Parrett, Dolores
2018-06-01
To address an increase in unexpected poor outcomes in term neonates, our team developed a goal of high reliability and improved fetal safety in the culture of the Labor and Delivery nursing department. We implemented interdisciplinary reviews of fetal heart rate, along with a Category II fetal heart rate management algorithm and a fetal heart rate assessment rapid response alert to call for unscheduled reviews when needed. Enhanced communication between nurses and other clinicians supported an interdisciplinary approach to fetal safety, and we observed an improvement in health outcomes for term neonates. We share our experience with the intention of making our methods available to any labor and delivery unit team committed to safe, high-quality care and service excellence. Copyright © 2018 AWHONN. Published by Elsevier Inc. All rights reserved.
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Human Fetal Heart Rate Dishabituation between Thirty and Thirty-Two Weeks Gestation.
ERIC Educational Resources Information Center
Sandman, Curt A.; Wadhwa, Pathik; Hetrick, William; Porto, Manuel; Peeke, Harmon V. S.
1997-01-01
Examined the ability of 32-week human fetuses to learn and recall information. Found a significant heart rate habituation pattern for a series of vibroacoustic stimuli. After a single novel stimulus, the heart rate to stimulus 1 reemerged. Uterine contractions were not related to presentation of the novel stimulus or change in heart rate after the…
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Patterns of Interspecific Variation in the Heart Rates of Embryonic Reptiles
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
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Heart Rate Monitor for Portable MP3 Player.
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.
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Estimation of heart rate variability using a compact radiofrequency motion sensor.
Sugita, Norihiro; Matsuoka, Narumi; Yoshizawa, Makoto; Abe, Makoto; Homma, Noriyasu; Otake, Hideharu; Kim, Junghyun; Ohtaki, Yukio
2015-12-01
Physiological indices that reflect autonomic nervous activity are considered useful for monitoring peoples' health on a daily basis. A number of such indices are derived from heart rate variability, which is obtained by a radiofrequency (RF) motion sensor without making physical contact with the user's body. However, the bulkiness of RF motion sensors used in previous studies makes them unsuitable for home use. In this study, a new method to measure heart rate variability using a compact RF motion sensor that is sufficiently small to fit in a user's shirt pocket is proposed. To extract a heart rate related component from the sensor signal, an algorithm that optimizes a digital filter based on the power spectral density of the signal is proposed. The signals of the RF motion sensor were measured for 29 subjects during the resting state and their heart rate variability was estimated from the measured signals using the proposed method and a conventional method. A correlation coefficient between true heart rate and heart rate estimated from the proposed method was 0.69. Further, the experimental results showed the viability of the RF sensor for monitoring autonomic nervous activity. However, some improvements such as controlling the direction of sensing were necessary for stable measurement. Copyright © 2015 IPEM. Published by Elsevier Ltd. All rights reserved.
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Effect of varying heart rate on intra-ventricular filling fluid dynamics
NASA Astrophysics Data System (ADS)
Santhanakrishnan, Arvind; Okafor, Ikechukwu; Angirish, Yagna; Yoganathan, Ajit
2013-11-01
Impaired exercise tolerance is used to delineate asymptomatic patients during the clinical diagnosis of diastolic left heart failure. Examining the effects of varying heart rate on intra-ventricular filling can provide a physical understanding of the specific flow characteristics that are impacted during exercise. In this study, diastolic filling was investigated with an anatomical left ventricle (LV) physical model under normal heart rate of 70 bpm, and varying exercise conditions of 100 bpm and 120 bpm. The LV model was incorporated into a flow loop and tuned for physiological inflow rates and outflow pressures. 2D PIV measurements were conducted along 3 parallel longitudinal planes. The systemic pressure was maintained the same across all test conditions. The E/A ratio was maintained within 1.0-1.2 across all heart rates. The strength of the mitral vortex ring formed during E-wave, as well as the peak incoming jet velocity, decreased with increasing heart rate. During peak flow of the A-wave, the vortex ring propagated farther into the LV for 120 bpm as compared to 70 bpm. The results point to the heightened role of the atrial kick for optimal LV filling during exercise conditions. This study was funded by a grant from the National Heart, Lung and Blood Institute (RO1HL70262).
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Signal processing methodologies for an acoustic fetal heart rate monitor
NASA Technical Reports Server (NTRS)
Pretlow, Robert A., III; Stoughton, John W.
1992-01-01
Research and development is presented of real time signal processing methodologies for the detection of fetal heart tones within a noise-contaminated signal from a passive acoustic sensor. A linear predictor algorithm is utilized for detection of the heart tone event and additional processing derives heart rate. The linear predictor is adaptively 'trained' in a least mean square error sense on generic fetal heart tones recorded from patients. A real time monitor system is described which outputs to a strip chart recorder for plotting the time history of the fetal heart rate. The system is validated in the context of the fetal nonstress test. Comparisons are made with ultrasonic nonstress tests on a series of patients. Comparative data provides favorable indications of the feasibility of the acoustic monitor for clinical use.
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Ho, Thomas C T; Chen, Xiang
2011-01-01
"Musica delenit bestiam feram" translates into "Music soothes the savage beast". There is a hidden truth in this ancient quip passed down from generations. Besides soothing the heart, it also incites the heart to a healthier level of heart rate variability (HRV). In this paper, an approach to use and test music and biofeedback to increase the heart rate variability for people facing daily stress is discussed. By determining the music tempo variability (MTV) of a piece of music and current heart rate variability, iHeartLift is able to compare the 2 trends and locate a musical piece that is suited to increase the user's heart rate variability to a healthier level. With biofeedback, the 2 trends are continuously compared in real-time and the musical piece is changed in accordance with the current comparisons. A study was conducted and it was generally found that HRV can be uplifted by music regardless of language and meaning of musical lyrics but with limitations to musical genre.
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Perinatal sulfur dioxide exposure alters brainstem parasympathetic control of heart rate
Woerman, Amanda L.; Mendelowitz, David
2013-01-01
Aims Sulfur dioxide (SO2) is an air pollutant that impedes neonatal development and induces adverse cardiorespiratory health effects, including tachycardia. Here, an animal model was developed that enabled characterization of (i) in vivo alterations in heart rate and (ii) altered activity in brainstem neurons that control heart rate after perinatal SO2 exposure. Methods and results Pregnant Sprague–Dawley dams and their pups were exposed to 5 parts per million SO2 for 1 h daily throughout gestation and 6 days postnatal. Electrocardiograms were recorded from pups at 5 days postnatal to examine changes in basal and diving reflex-evoked changes in heart rate following perinatal SO2 exposure. In vitro studies employed whole-cell patch-clamp electrophysiology to examine changes in neurotransmission to cardiac vagal neurons within the nucleus ambiguus upon SO2 exposure using a preparation that maintains fictive inspiratory activity recorded from the hypoglossal rootlet. Perinatal SO2 exposure increased heart rate and blunted the parasympathetic-mediated diving reflex-evoked changes in heart rate. Neither spontaneous nor inspiratory-related inhibitory GABAergic or glycinergic neurotransmission to cardiac vagal neurons was altered by SO2 exposure. However, excitatory glutamatergic neurotransmission was decreased by 51.2% upon SO2 exposure. This diminished excitatory neurotransmission was tetrodotoxin-sensitive, indicating SO2 exposure impaired the activity of preceding glutamatergic neurons that synapse upon cardiac vagal neurons. Conclusions Diminished glutamatergic, but unaltered inhibitory neurotransmission to cardiac vagal neurons provides a mechanism for the observed SO2-induced elevated heart rate via an impairment of brainstem cardioinhibitory parasympathetic activity to the heart. PMID:23504550
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Goudkamp, Jacqueline E; Seebacher, Frank; Ahern, Mark; Franklin, Craig E
2004-07-01
Differential heart rates during heating and cooling (heart rate hysteresis) are an important thermoregulatory mechanism in ectothermic reptiles. We speculate that heart rate hysteresis has evolved alongside vascularisation, and to determine whether this phenomenon occurs in a lineage with vascularised circulatory systems that is phylogenetically distant from reptiles, we measured the response of heart rate to convective heat transfer in the Australian freshwater crayfish, Cherax destructor. Heart rate during convective heating (from 20 to 30 degrees C) was significantly faster than during cooling for any given body temperature. Heart rate declined rapidly immediately following the removal of the heat source, despite only negligible losses in body temperature. This heart rate 'hysteresis' is similar to the pattern reported in many reptiles and, by varying peripheral blood flow, it is presumed to confer thermoregulatory benefits particularly given the thermal sensitivity of many physiological rate functions in crustaceans.
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Using complexity metrics with R-R intervals and BPM heart rate measures.
Wallot, Sebastian; Fusaroli, Riccardo; Tylén, Kristian; Jegindø, Else-Marie
2013-01-01
Lately, growing attention in the health sciences has been paid to the dynamics of heart rate as indicator of impending failures and for prognoses. Likewise, in social and cognitive sciences, heart rate is increasingly employed as a measure of arousal, emotional engagement and as a marker of interpersonal coordination. However, there is no consensus about which measurements and analytical tools are most appropriate in mapping the temporal dynamics of heart rate and quite different metrics are reported in the literature. As complexity metrics of heart rate variability depend critically on variability of the data, different choices regarding the kind of measures can have a substantial impact on the results. In this article we compare linear and non-linear statistics on two prominent types of heart beat data, beat-to-beat intervals (R-R interval) and beats-per-min (BPM). As a proof-of-concept, we employ a simple rest-exercise-rest task and show that non-linear statistics-fractal (DFA) and recurrence (RQA) analyses-reveal information about heart beat activity above and beyond the simple level of heart rate. Non-linear statistics unveil sustained post-exercise effects on heart rate dynamics, but their power to do so critically depends on the type data that is employed: While R-R intervals are very susceptible to non-linear analyses, the success of non-linear methods for BPM data critically depends on their construction. Generally, "oversampled" BPM time-series can be recommended as they retain most of the information about non-linear aspects of heart beat dynamics.
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Using complexity metrics with R-R intervals and BPM heart rate measures
Wallot, Sebastian; Fusaroli, Riccardo; Tylén, Kristian; Jegindø, Else-Marie
2013-01-01
Lately, growing attention in the health sciences has been paid to the dynamics of heart rate as indicator of impending failures and for prognoses. Likewise, in social and cognitive sciences, heart rate is increasingly employed as a measure of arousal, emotional engagement and as a marker of interpersonal coordination. However, there is no consensus about which measurements and analytical tools are most appropriate in mapping the temporal dynamics of heart rate and quite different metrics are reported in the literature. As complexity metrics of heart rate variability depend critically on variability of the data, different choices regarding the kind of measures can have a substantial impact on the results. In this article we compare linear and non-linear statistics on two prominent types of heart beat data, beat-to-beat intervals (R-R interval) and beats-per-min (BPM). As a proof-of-concept, we employ a simple rest-exercise-rest task and show that non-linear statistics—fractal (DFA) and recurrence (RQA) analyses—reveal information about heart beat activity above and beyond the simple level of heart rate. Non-linear statistics unveil sustained post-exercise effects on heart rate dynamics, but their power to do so critically depends on the type data that is employed: While R-R intervals are very susceptible to non-linear analyses, the success of non-linear methods for BPM data critically depends on their construction. Generally, “oversampled” BPM time-series can be recommended as they retain most of the information about non-linear aspects of heart beat dynamics. PMID:23964244
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Heart Rate Recovery, Physical Activity Level, and Functional Status in Subjects With COPD.
Morita, Andrea A; Silva, Laís K O; Bisca, Gianna W; Oliveira, Joice M; Hernandes, Nidia A; Pitta, Fabio; Furlanetto, Karina C
2018-05-15
A normal heart rate reflects the balance between the sympathetic and parasympathetic autonomic nervous system. When the difference between heart rate at the end of an exercise test and after 1 min of recovery, known as the 1-min heart rate recovery, is ≤ 12 beats/min, this may indicate an abnormal delay. We sought to compare physical activity patterns and subjects' functional status with COPD with or without delayed 1-min heart rate recovery after the 6-min walk test (6MWT). 145 subjects with COPD (78 men, median [interquartile range (IQR)] age 65 [60-73] y, body mass index 25 [21-30] kg/m 2 , FEV 1 45 ± 15% predicted) were underwent the following assessments: spirometry, 6MWT, functional status, and physical activity in daily life (PADL). A delayed heart rate recovery of 1 min was defined as ≤ 12 beats/min. Subjects with delayed 1-min heart rate recovery walked a shorter distance in the 6MWT compared to subjects without delayed heart rate recovery (median [IQR] 435 [390-507] m vs 477 [425-515] m, P = .01; 81 [71-87] vs 87 [79-98]% predicted, P = .002). Regarding PADL, subjects with delayed heart rate recovery spent less time in the standing position (mean ± SD 185 ± 89 min vs 250 ± 107 min, P = .002) and more time in sedentary positions (472 ± 110 min vs 394 ± 129 min, P = .002). Scores based on the self-care domain of the London Chest Activity of Daily Living questionnaire and the activity domain of the Pulmonary Functional Status and Dyspnea questionnaire were also worse in the group with delayed heart rate recovery (6 ± 2 points vs 5 ± 2 points; P = .039 and 29 ± 24 points vs 19 ± 17 points; P = .037, respectively). Individuals with COPD who exhibit delayed 1-min heart rate recovery after the 6MWT exhibited worse exercise capacity as well as a more pronounced sedentary lifestyle and worse functional status than those without delayed heart rate recovery. Despite its assessment simplicity, heart rate recovery after the 6MWT can be further explored
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Optically Remote Noncontact Heart Rates Sensing Technique
NASA Astrophysics Data System (ADS)
Thongkongoum, W.; Boonduang, S.; Limsuwan, P.
2017-09-01
Heart rate monitoring via optically remote noncontact technique was reported in this research. A green laser (5 mW, 532±10 nm) was projected onto the left carotid artery. The reflected laser light on the screen carried the deviation of the interference patterns. The interference patterns were recorded by the digital camera. The recorded videos of the interference patterns were frame by frame analysed by 2 standard digital image processing (DIP) techniques, block matching (BM) and optical flow (OF) techniques. The region of interest (ROI) pixels within the interference patterns were analysed for periodically changes of the interference patterns due to the heart pumping action. Both results of BM and OF techniques were compared with the reference medical heart rate monitoring device by which a contact measurement using pulse transit technique. The results obtained from BM technique was 74.67 bpm (beats per minute) and OF technique was 75.95 bpm. Those results when compared with the reference value of 75.43±1 bpm, the errors were found to be 1.01% and 0.69%, respectively.
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Effects of Vibration and G-Loading on Heart Rate, Breathing Rate, and Response Time
NASA Technical Reports Server (NTRS)
Godinez, Angelica; Ayzenberg, Ruthie; Liston, Dorian B.; Stone, Leland S.
2013-01-01
Aerospace and applied environments commonly expose pilots and astronauts to G-loading and vibration, alone and in combination, with well-known sensorimotor (Cohen, 1970) and performance consequences (Adelstein et al., 2008). Physiological variables such as heart rate (HR) and breathing rate (BR) have been shown to increase with G-loading (Yajima et al., 1994) and vibration (e.g. Guignard, 1965, 1985) alone. To examine the effects of G-loading and vibration, alone and in combination, we measured heart rate and breathing rate under aerospace-relevant conditions (G-loads of 1 Gx and 3.8 Gx; vibration of 0.5 gx at 8, 12, and 16 Hz).
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A new method to measure heart rate with EMFi and PVDF materials.
Kärki, S; Lekkala, J
2009-01-01
In this paper we propose a new simple method to measure the heart rate of a person sitting on a chair or lying in a bed. The heart rate is measured with a thin sensor pad consisting of separate electromechanical film (EMFi) and polyvinylidenefluoride (PVDF) transducers located beneath the leg of chair or bed. This study aims to evaluate the operation of the sensor system with measurements, and also to compare the results provided by the two transducer materials. Based on the results obtained here, the heart rates measured with the transducers mainly corresponded to the values of reference ECG signal. Some minor differences between the heart rate values of PVDF and EMFi appeared, especially in supine position, possible due to the material sensitivities to different force directions. However, to conclude, both materials seem to be convenient for this kind of measurement of heart rate.
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Heart rate detection from an electronic weighing scale.
González-Landaeta, R; Casas, O; Pallàs-Areny, R
2008-08-01
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.
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Guided imagery, anxiety, heart rate, and heart rate variability during centrifuge training.
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.
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Resonance of about-weekly human heart rate rhythm with solar activity change.
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.
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Effect of Age and Other Factors on Maximal Heart Rate.
ERIC Educational Resources Information Center
Londeree, Ben R.; Moeschberger, Melvin L.
1982-01-01
To reduce confusion regarding reported effects of age on maximal exercise heart rate, a comprehensive review of the relevant English literature was conducted. Data on maximal heart rate after exercising with a bicycle, a treadmill, and after swimming were analyzed with regard to physical fitness and to age, sex, and racial differences. (Authors/PP)
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Effects of different training amplitudes on heart rate and heart rate variability in young rowers.
Vaz, Marcelo S; Picanço, Luan M; Del Vecchio, Fabrício B
2014-10-01
The aim of this study was to investigate the autonomic nervous system recovery and the psychological response as a result of 3 training amplitudes on heart rate (HR), heart rate variability (HRV), and rate of perceived exertion (RPE) in rowing. Eight young rowers (16.8 ± 1.4 years) performed, in a randomized fashion, 2 sessions of high-intensity interval training, with high and low amplitude and a continuous training (CT) session, with the same exercise duration (10 minutes) and mean intensity (60% of maximal stroke test). The data of HR, HRV, and RPE were collected 5 minutes before, immediately after each session, and 24 hours later. High amplitude promoted higher impact in maximum HR (p ≤ 0.05) and RPE (p < 0.001) when compared with CT. For the time domain HRV variable, there was a statistically significant difference between moments of rest (pretraining or post 24 hours) and posttraining in all training sessions. Originally, we conclude that training with higher load variation between effort and recovery impacts HRV, HR, and RPE with greater intensity, but the younger rowers were ready for new training sessions 24 hours after either training method. Coaches can use the polarized training method, observing the stimulus nature and time required for recovery, because it may be an adequate strategy for the development of rower's conditioning.
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Variability in heart rate recovery measurements over 1 year in healthy, middle-aged adults.
Mellis, M G; Ingle, L; Carroll, S
2014-02-01
This study assessed the longer-term (12-month) variability in post-exercise heart rate recovery following a submaximal exercise test. Longitudinal data was analysed for 97 healthy middle-aged adults (74 male, 23 female) from 2 occasions, 12 months apart. Participants were retrospectively selected if they had stable physical activity habits, submaximal treadmill fitness and anthropometric measurements between the 2 assessment visits. A submaximal Bruce treadmill test was performed to at least 85% age-predicted maximum heart rate. Absolute heart rate and Δ heart rate recovery (change from peak exercise heart rate) were recorded for 1 and 2 min post-exercise in an immediate supine position. Heart rate recovery at both time-points was shown to be reliable with intra-class correlation coefficient values ≥ 0.714. Absolute heart rate 1-min post-exercise showed the strongest agreement between repeat tests (r = 0.867, P < 0.001). Lower coefficient of variation (≤ 10.2%) and narrower limits of agreement were found for actual heart rate values rather than Δ heart rate recovery, and for 1-min rather than 2-min post-exercise recovery time points. Log-transformed values generated better variability with acceptable coefficient of variation for all measures (2.2-10%). Overall, 1 min post-exercise heart rate recovery data had least variability over the 12-month period in apparently healthy middle-aged adults. © Georg Thieme Verlag KG Stuttgart · New York.
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Elevated resting heart rate is associated with dyslipidemia in middle-aged and elderly Chinese.
Sun, Ji Chao; Huang, Xiao Lin; Deng, Xin Ru; Lv, Xiao Fei; Lu, Jie Li; Chen, Yu Hong; Bi, Yu Fang; Wang, Wei Qing; Xu, Min; Ning, Guang
2014-08-01
To study the relationship between resting heart rate and blood lipid level. A total of 9 415 subjects aged ⋝ 40 years were included in the present study. Their resting heart rate was monitored and their serum levels of triglyceride (TG), total cholesterol (TC), low density lipoprotein cholesterol (LDL-C) and high density lipoprotein cholesterol (HDL-C) were measured to define dyslipidemia according to the 2007 Chinese Guidelines on Prevention and Treatment of Dyslipidemia in Adults. The subjects were divided into group A with their resting heart rate <70 beats/min, group B with their resting heart rate =70-79 beats/min, group C with their resting heart rate =80-89 beats/min, and group D with their resting heart rate ⋝ 90 beats/min. High TG, TC, and LDL-C were presented across the resting heart rate (Ptrend <0.01). Multiple logistic regression analysis revealed that the risk of high TG and TC was higher in subjects with their resting heart rate ⋝ 90 beats/min than in those with their resting heart rate <70 beats/min (OR=1.42; 95% CI: 1.16-1.74 and OR=1.33; 95% CI: 1.09-1.64, respectively). Elevated resting heart rate is associated with high TG and TC in middle-aged and elderly Chinese subjects. Copyright © 2014 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.
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Menown, Ian BA; Davies, Simon; Gupta, Sandeep; Kalra, Paul R; Lang, Chim C; Morley, Chris; Padmanabhan, Sandosh
2013-01-01
Background Data from large epidemiological studies suggest that elevated heart rate is independently associated with cardiovascular and all-cause mortality in patients with hypertension and in those with established cardiovascular disease. Clinical trial findings also suggest that the favorable effects of beta-blockers and other heart rate–lowering agents in patients with acute myocardial infarction and congestive heart failure may be, at least in part, due to their heart rate–lowering effects. Contemporary clinical outcome prediction models such as the Global Registry of Acute Coronary Events (GRACE) score include admission heart rate as an independent risk factor. Aims This article critically reviews the key epidemiology concerning heart rate and cardiovascular risk, potential mechanisms through which an elevated resting heart rate may be disadvantageous and evaluates clinical trial outcomes associated with pharmacological reduction in resting heart rate. Conclusions Prospective randomised data from patients with significant coronary heart disease or heart failure suggest that intervention to reduce heart rate in those with a resting heart rate >70 bpm may reduce cardiovascular risk. Given the established observational data and randomised trial evidence, it now appears appropriate to include reduction of elevated resting heart rate by lifestyle +/− pharmacological therapy as part of a secondary prevention strategy in patients with cardiovascular disease. PMID:22954325
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The effect of competition on heart rate during kart driving: A field study.
Matsumura, Kenta; Yamakoshi, Takehiro; Yamakoshi, Yasuhiro; Rolfe, Peter
2011-09-09
Both the act of competing, which can create a kind of mental stress, and participation in motor sports, which induces physical stress from intense g-forces, are known to increase heart rate dramatically. However, little is known about the specific effect of competition on heart rate during motor sports, particularly during four-wheel car driving. The goal of this preliminary study, therefore, was to investigate whether competition increases heart rate under such situations. The participants drove an entry-level formula kart during two competitive races and during solo driving against the clock while heart rate and g-forces were measured. Analyses showed that heart rate values during the races (168.8 beats/min) were significantly higher than those during solo driving (140.9 beats/min) and rest (75.1 beats/min). The results of this preliminary study indicate that competition heightens heart rate during four-wheel car driving. Kart drivers should be concerned about maintaining good health and developing physical strength.
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The effect of competition on heart rate during kart driving: A field study
2011-01-01
Background Both the act of competing, which can create a kind of mental stress, and participation in motor sports, which induces physical stress from intense g-forces, are known to increase heart rate dramatically. However, little is known about the specific effect of competition on heart rate during motor sports, particularly during four-wheel car driving. The goal of this preliminary study, therefore, was to investigate whether competition increases heart rate under such situations. Findings The participants drove an entry-level formula kart during two competitive races and during solo driving against the clock while heart rate and g-forces were measured. Analyses showed that heart rate values during the races (168.8 beats/min) were significantly higher than those during solo driving (140.9 beats/min) and rest (75.1 beats/min). Conclusions The results of this preliminary study indicate that competition heightens heart rate during four-wheel car driving. Kart drivers should be concerned about maintaining good health and developing physical strength. PMID:21906298
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Makimoto, Hisaki; Blockhaus, Christian; Meyer, Christian; Lin, Tina; Jungen, Christiane; Eickholt, Christian; Clasen, Lukas; Schmidt, Jan; Kurt, Muhammed; Müller, Patrick; Shin, Dong-In; Kelm, Malte; Fürnkranz, Alexander
2018-03-01
The severity of symptoms during atrial fibrillation (AF) may be influenced by heart rate and blood pressure variation, due to irregular beats and the related adaptations in baroreflex sensitivity. This study investigated whether heart rate turbulence (HRT) as a reflection of baroreflex sensitivity is related to symptom severity during AF. Ninety-seven patients (pts) who underwent electrophysiological study were enrolled. Consecutive 56 pts had paroxysmal AF (21 with milder symptoms [EHRA I or II; Group-M], 35 with severe symptoms [EHRA III or IV; Group-S]), and 41 age-matched controls without AF were included. After delivering a single ventricular extrastimulus during sinus rhythm and repeating the process 10 times, the quantification of HRT was performed by measuring turbulence onset (TO: heart rate acceleration) and turbulence slope (TS: rate of heart rate deceleration). Group-M pts showed significantly diminished TO as compared to controls and Group-S pts (P = 0.012). There was no significant difference of the TS between the 3 groups. Given that a TO ≥ 0% or TS ≤ 2.5 ms/RR was considered abnormal, Group-M pts showed significantly higher incidences of abnormal HRT as compared to controls and Group-S pts (71% vs 40% vs 21%, respectively, P = 0.0012). Regression analysis demonstrated an independent and significant association between a diminished TO and milder AF symptoms (P < 0.05). The usual heart rate acceleration after premature ventricular contraction is significantly diminished in pts with milder AF symptoms as compared to pts with severe AF symptoms. The mechanism of association between this diminished response and symptoms should be further investigated.
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Heart rate measurement based on a time-lapse image.
Takano, Chihiro; Ohta, Yuji
2007-10-01
Using a time-lapse image acquired from a CCD camera, we developed a non-contact and non-invasive device, which could measure both the respiratory and pulse rate simultaneously. The time-lapse image of a part of the subject's skin was consecutively captured, and the changes in the average image brightness of the region of interest (ROI) were measured for 30s. The brightness data were processed by a series of operations of interpolation as follows a first-order derivative, a low pass filter of 2 Hz, and a sixth-order auto-regressive (AR) spectral analysis. Fourteen sound and healthy female subjects (22-27 years of age) participated in the experiments. Each subject was told to keep a relaxed seating posture with no physical restriction. At the same time, heart rate was measured by a pulse oximeter and respiratory rate was measured by a thermistor placed at the external naris. Using AR spectral analysis, two clear peaks could be detected at approximately 0.3 and 1.2 Hz. The peaks were thought to correspond to the respiratory rate and the heart rate. Correlation coefficients of 0.90 and 0.93 were obtained for the measurement of heart rate and respiratory rate, respectively.
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Heart rate sensitive optical coherence angiography
NASA Astrophysics Data System (ADS)
Alvarez, Karl; Lopez-Tremoleda, Jordi; Donnan, Rob; Michael-Titus, Adina T.; Tomlins, Peter H.
2018-02-01
Optical coherence angiography (OCA) enables visualisation of three-dimensional micro-vasculature from optical coherence tomography data volumes. Typically, various statistical methods are used to discriminate static tissue from blood flow within vessels. In this paper, we introduce a new method that relies upon the beating heart frequency to isolate blood vessels from the surrounding tissue. Vascular blood flow is assumed to be more strongly modulated by the heart-beat compared to surrounding tissue and therefore short-time Fourier transform of sequential measurements can discriminate the two. Furthermore, it is demonstrated that adjacent B-Scans within an OCT data volume can provide the required sampling frequency. As such, the technique can be considered to be a spatially mapped variation of photoplethysmography (PPG), whereby each image voxel operates as a PPG detector. This principle is demonstrated using both a model system and in vivo for monitoring the vascular changes effected by traumatic brain injury in mice. In vivo measurements were acquired at an A-Scan rate of 10kHz to form a 500x500x512 (lateral x lateral x axial) pixel volume, enabling sequential sampling of the mouse heart rate in an expected range of 300-600 bpm. One of the advantages of this new OCA processing method is that it can be used in conjunction with existing algorithms as an additional filter for signal to noise enhancement.
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Heart rate estimation from FBG sensors using cepstrum analysis and sensor fusion.
Zhu, Yongwei; Fook, Victor Foo Siang; Jianzhong, Emily Hao; Maniyeri, Jayachandran; Guan, Cuntai; Zhang, Haihong; Jiliang, Eugene Phua; Biswas, Jit
2014-01-01
This paper presents a method of estimating heart rate from arrays of fiber Bragg grating (FBG) sensors embedded in a mat. A cepstral domain signal analysis technique is proposed to characterize Ballistocardiogram (BCG) signals. With this technique, the average heart beat intervals can be estimated by detecting the dominant peaks in the cepstrum, and the signals of multiple sensors can be fused together to obtain higher signal to noise ratio than each individual sensor. Experiments were conducted with 10 human subjects lying on 2 different postures on a bed. The estimated heart rate from BCG was compared with heart rate ground truth from ECG, and the mean error of estimation obtained is below 1 beat per minute (BPM). The results show that the proposed fusion method can achieve promising heart rate measurement accuracy and robustness against various sensor contact conditions.
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Short-term variability of blood pressure and heart rate in hyperthyroidism.
Girard, A; Hugues, F C; Le Jeunne, C; Elghozi, J L
1998-06-01
The effect of hyperthyroidism on the short-term memory variability of blood pressure and heart rate was evaluated in 12 untreated hyperthyroid patients during thyrotoxicosis and after a 6 1/2 month treatment designed to achieve a stable euthyroid state. Beat-by-beat finger blood pressure was measured with a Finapres device. The pulse interval, from which pulse rate was derived, was obtained from the blood pressure signal. Due to the significant change in heart rhythm associated with thyrotoxicosis, both pulse interval (taken as a surrogate of heart period) and pulse rate (taken as a surrogate of heart rate) were computed. Power spectral analysis showed a reduction in the overall heart period variability in the supine position in the hyperthyroid compared to the euthyroid state. This effect was observed in the low-frequency (0.005-0.068 Hz), mid-frequency (0.068-0.127 Hz) and high-frequency (respiratory) domains as well, with a significant reduction of the modulus of these bands of 31%, 35% and 47%, respectively. The heart rate spectral modulus also exhibited a reduction of the high-frequency component (31%) in the supine position in the hyperthyroid subjects. These changes in heart rhythmicity corroborate a vagal deficit in hyperthyroidism. In addition, blood pressure spectral power exhibited a significant deficit in the orthostatism-induced mid-frequency systolic blood pressure rise in the hyperthyroid state (64%) compared with the euthyroid state. This observation may reflect a reduced vascular sympathetic activation with standing. The resulting vasodilatation could well contribute to normalize blood pressure in thyrotoxicosis in which cardiac output is increased.
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Deriving temperature and age appropriate heart rate centiles for children with acute infections.
Thompson, M; Harnden, A; Perera, R; Mayon-White, R; Smith, L; McLeod, D; Mant, D
2009-05-01
To describe the reference range for heart rate in children aged 3 months-10 years presenting to primary care with self-limiting infections. Cross-sectional study of children presenting to primary care with suspected acute infection. Heart rate was measured using a pulse oximeter and axillary temperature using an electronic thermometer. Centile charts of heart rates expected at given temperatures for children with self-limiting infections were calculated. Ten general practice surgeries and two out-of-hours centres in England. 1933 children presenting with suspected acute infections were recruited from in-hours general practice surgeries (1050 or 54.3%) or out-of-hours centres (883 or 45.7%). After excluding children who subsequently attended hospital and those without a final diagnosis of acute infection, 1589 children were used to create the centile charts of whom (859 or 54.1%) had upper respiratory tract infections and (215 or 13.5%) non-specific viral illness. Median, 75th, 90th and 97th centiles of heart rate at each temperature level. Heart rate increased by 9.9-14.1 bpm with each 1 degrees C increment in temperature. The 50th, 75th, 90th and 97th centiles of heart rate at each temperature level are presented graphically. Age-specific centile charts of heart rates expected at different temperatures should be used by clinicians in the initial assessment of children with acute infections. The charts will identify children who have a heart rate higher than expected for a given temperature and facilitate the interpretation of changes in heart rate on reassessment. Further research on the predictive value of the centile charts is needed to optimise their diagnostic utility.
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Universal structures of normal and pathological heart rate variability.
Gañán-Calvo, Alfonso M; Fajardo-López, Juan
2016-02-25
The circulatory system of living organisms is an autonomous mechanical system softly tuned with the respiratory system, and both developed by evolution as a response to the complex oxygen demand patterns associated with motion. Circulatory health is rooted in adaptability, which entails an inherent variability. Here, we show that a generalized N-dimensional normalized graph representing heart rate variability reveals two universal arrhythmic patterns as specific signatures of health one reflects cardiac adaptability, and the other the cardiac-respiratory rate tuning. In addition, we identify at least three universal arrhythmic profiles whose presences raise in proportional detriment of the two healthy ones in pathological conditions (myocardial infarction; heart failure; and recovery from sudden death). The presence of the identified universal arrhythmic structures together with the position of the centre of mass of the heart rate variability graph provide a unique quantitative assessment of the health-pathology gradient.
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Kowalik, Sylwester; Janczarek, Iwona; Kędzierski, Witold; Stachurska, Anna; Wilk, Izabela
2017-04-01
The objective of this study was to assess the effect of relaxing massage on the heart rate (HR) and heart rate variability (HRV) in young racehorses during their first racing season. In the study, 72 Purebred Arabian racehorses were included. The study was implemented during the full race season. The horses from control and experimental groups were included in regular race training 6 days a week. The horses from the experimental group were additionally subject to the relaxing massage 3 days a week during the whole study. HR and HRV were assumed as indicators of the emotional state of the horses. The measurements were taken six times, every 4-5 weeks. The HRV parameters were measured at rest, during grooming and saddling the horse and during warm-up walking under a rider. The changes of the parameters throughout the season suggest that the relaxing massage may be effectively used to make the racehorses more relaxed and calm. Moreover, the horses from the experimental group had better race performance records. © 2016 Japanese Society of Animal Science.
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Effect of Heart Rate on Arterial Stiffness as Assessed by Pulse Wave Velocity.
Tan, Isabella; Butlin, Mark; Spronck, Bart; Xiao, Huanguang; Avolio, Alberto
2017-07-24
Vascular assessment is becoming increasingly important in the diagnosis of cardiovascular diseases. In particular, clinical assessment of arterial stiffness, as measured by pulse wave velocity (PWV), is gaining increased interest due to the recognition of PWV as an influential factor on the prognosis of hypertension as well as being an independent predictor of cardiovascular and all-cause mortality. Whilst age and blood pressure are established as the two major determinants of PWV, the influence of heart rate on PWV measurements remains controversial with conflicting results being observed in both acute and epidemiological studies. In a majority of studies investigating the acute effects of heart rate on PWV, results were confounded by concomitant changes in blood pressure. Observations from epidemiological studies have also failed to converge, with approximately just half of such studies reporting a significant blood-pressure-independent association between heart rate and PWV. Further to the lack of consensus on the effects of heart rate on PWV, the possible mechanisms contributing to observed PWV changes with heart rate have yet to be fully elucidated, although many investigators have attributed heart-rate related changes in arterial stiffness to the viscoelasticity of the arterial wall. With elevated heart rate being an independent prognostic factor of cardiovascular disease and its association with hypertension, the interaction between heart rate and PWV continues to be relevant in assessing cardiovascular risk. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.
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Technology platform development for targeted plasma metabolites in human heart failure.
Chan, Cy X'avia; Khan, Anjum A; Choi, Jh Howard; Ng, Cm Dominic; Cadeiras, Martin; Deng, Mario; Ping, Peipei
2013-01-01
Heart failure is a multifactorial disease associated with staggeringly high morbidity and motility. Recently, alterations of multiple metabolites have been implicated in heart failure; however, the lack of an effective technology platform to assess these metabolites has limited our understanding on how they contribute to this disease phenotype. We have successfully developed a new workflow combining specific sample preparation with tandem mass spectrometry that enables us to extract most of the targeted metabolites. 19 metabolites were chosen ascribing to their biological relevance to heart failure, including extracellular matrix remodeling, inflammation, insulin resistance, renal dysfunction, and cardioprotection against ischemic injury. In this report, we systematically engineered, optimized and refined a protocol applicable to human plasma samples; this study contributes to the methodology development with respect to deproteinization, incubation, reconstitution, and detection with mass spectrometry. The deproteinization step was optimized with 20% methanol/ethanol at a plasma:solvent ratio of 1:3. Subsequently, an incubation step was implemented which remarkably enhanced the metabolite signals and the number of metabolite peaks detected by mass spectrometry in both positive and negative modes. With respect to the step of reconstitution, 0.1% formic acid was designated as the reconstitution solvent vs. 6.5 mM ammonium bicarbonate, based on the comparable number of metabolite peaks detected in both solvents, and yet the signal detected in the former was higher. By adapting this finalized protocol, we were able to retrieve 13 out of 19 targeted metabolites from human plasma. We have successfully devised a simple albeit effective workflow for the targeted plasma metabolites relevant to human heart failure. This will be employed in tandem with high throughput liquid chromatography mass spectrometry platform to validate and characterize these potential metabolic
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Rayan, Mona; Tawfik, Mazen; Alabd, Ali; Gamal, Amr
2011-08-01
To prospectively assess the safety and efficacy of ivabradine in patients with idiopathic dilated cardiomyopathy. We included 35 patients with idiopathic dilated cardiomyopathy with an ejection fraction (EF) <40% and heart rate >70 beats/min despite optimal medical therapy, according to the international guidelines in this prospective, non-randomized, single-arm, open-label safety study. Ivabradine was used as an add-on therapy to the maximally tolerated b-blocker in an increasing titrated dose till a target dose of 15 mg/day or resting heart rate of 60 beats/min for 3 months. During follow-up period the safety, patient tolerance and efficacy of this drug were assessed. All patients underwent 12-lead resting electrocardiography and Holter monitoring at inclusion and after 3 months. Statistical analysis was accomplished using paired t-test and Pearson correlation analysis. We found a significant reduction in the resting heart rate by a mean of 25.9 ± 9.4%, without a significant change of blood pressure. There was no prolongation of PR, QTc or QRS durations. Ventricular ectopic activity showed significant reduction (p<0.001). There was a significant correlation between the resting heart rate, NYHA and left ventricular ejection fraction (p<0.001 for both). One patient developed photopsia and decompensation was observed in another patient. Ivabradine is a safe and effective drug in reducing resting heart rate, improving NYHA functional class without undesirable effects on conduction parameters or ectopic activity.
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Relationships between heart rate and age, bodyweight and breed in 10,849 dogs.
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 (P<0.001) but was higher in Chihuahuas. 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.
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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.
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Nagel, C; Erber, R; Bergmaier, C; Wulf, M; Aurich, J; Möstl, E; Aurich, C
2012-09-01
The mechanisms leading to parturition in the horse in many aspects differ from those in other species. Pregnancy is maintained not by progesterone but by 5α-pregnanes and the progestin precursor pregnenolone originates from the fetus. As parturition approaches, the fetal adrenal switches from pregnenolone to cortisol synthesis but it is not known whether cortisol crosses the placenta. We hypothesized that in parallel to fetal cortisol release, cortisol in the maternal circulation increases before foaling and this increase can be determined in both saliva and plasma. In addition, maternal, fetal and neonatal heart rate and heart rate variability were measured. In 25 pregnant mares, saliva for cortisol analysis was collected 4 times daily from 15 days before to 5 days after foaling. In 13 mares, in addition, fetomaternal electrocardiogram (ECG) recordings were made and blood samples for progestin and cortisol analysis were collected once daily. Heart rate (HR) was recorded until 5 days after foaling. The heart rate variability (HRV) variables standard deviation of the beat-to-beat (RR) interval (SDRR) and root mean square of successive RR differences (RMSSD) were calculated. From Days 15 to 4 before parturition, progestin concentration increased (peak 267 ± 42 ng/mL) and decreased thereafter (P < 0.05, day of foaling 113 ± 18 ng/mL). A prepartum increase in maternal cortisol concentrations was evident in blood (P < 0.05) and saliva (P < 0.05) and paralleled the decrease in progestin concentrations. In mares, HR remained constant during the last days of pregnancy but decreased within one day after parturition (P < 0.05) while maternal HRV did not change. In the fetus and neonate, HR increased from before to after birth (P < 0.05) indicating increasing demands on the cardiovascular system with adaptation to extrauterine life. Copyright © 2012 Elsevier Inc. All rights reserved.
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Currie, Katharine D; Rosen, Lee M; Millar, Philip J; McKelvie, Robert S; MacDonald, Maureen J
2013-06-01
Decreased heart rate variability and attenuated heart rate recovery following exercise are associated with an increased risk of mortality in cardiac patients. This study investigated the effects of 12 weeks of moderate-intensity endurance exercise (END) and a novel low-volume high-intensity interval exercise protocol (HIT) on measures of heart rate recovery and heart rate variability in patients with coronary artery disease (CAD). Fourteen males with CAD participated in 12 weeks of END or HIT training, each consisting of 2 supervised exercise sessions per week. END consisted of 30-50 min of continuous cycling at 60% peak power output (PPO). HIT involved ten 1-min intervals at 88% PPO separated by 1-min intervals at 10% PPO. Heart rate recovery at 1 min and 2 min was measured before and after training (pre- and post-training, respectively) using a submaximal exercise bout. Resting time and spectral and nonlinear domain measures of heart rate variability were calculated. Following 12 weeks of END and HIT, there was no change in heart rate recovery at 1 min (END, 40 ± 12 beats·min(-1) vs. 37 ± 19 beats·min(-1); HIT, 31 ± 8 beats·min(-1) vs. 35 ± 8 beats·min(-1); p ≥ 0.05 for pre- vs. post-training) or 2 min (END, 44 ± 18 beats·min(-1) vs. 43 ± 19 beats·min(-1); HIT, 42 ± 10 beats·min(-1) vs. 50 ± 6 beats·min(-1); p ≥ 0.05 for pre- vs. post-training). All heart rate variability indices were unchanged following END and HIT training. In conclusion, neither END nor HIT exercise programs elicited training-induced improvements in cardiac autonomic function in patients with CAD. The absence of improvements with training may be attributed to the optimal medical management and normative pretraining state of our sample.
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QRS peak detection for heart rate monitoring on Android smartphone
NASA Astrophysics Data System (ADS)
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.
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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. PMID:18327970
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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.
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ERIC Educational Resources Information Center
Duker, Pieter C.; Van den Munckhof, Marcia
2007-01-01
Five individuals, who were treated for severe self-injurious behaviors (SIB) with contingent electric shock, participated. Hereby, each occurrence of the target response was followed by a remotely administered aversive consequence. Participants' heart rates were compared at times when the active device of the equipment for the above procedure was…
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Smart pillow for heart-rate monitoring using a fiber optic sensor
NASA Astrophysics Data System (ADS)
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.
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Cognitive Performance and Heart Rate Variability: The Influence of Fitness Level
Luque-Casado, Antonio; Zabala, Mikel; Morales, Esther; Mateo-March, Manuel; Sanabria, Daniel
2013-01-01
In the present study, we investigated the relation between cognitive performance and heart rate variability as a function of fitness level. We measured the effect of three cognitive tasks (the psychomotor vigilance task, a temporal orienting task, and a duration discrimination task) on the heart rate variability of two groups of participants: a high-fit group and a low-fit group. Two major novel findings emerged from this study. First, the lowest values of heart rate variability were found during performance of the duration discrimination task, compared to the other two tasks. Second, the results showed a decrement in heart rate variability as a function of the time on task, although only in the low-fit group. Moreover, the high-fit group showed overall faster reaction times than the low-fit group in the psychomotor vigilance task, while there were not significant differences in performance between the two groups of participants in the other two cognitive tasks. In sum, our results highlighted the influence of cognitive processing on heart rate variability. Importantly, both behavioral and physiological results suggested that the main benefit obtained as a result of fitness level appeared to be associated with processes involving sustained attention. PMID:23437276
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An, Sang Min; Park, Jong Suk; Kim, Sang Ho
2014-03-01
The purpose of this research was to investigate the effects of exercise capacity, heart rate recovery and heart rate variability after high-intensity exercise on caffeine concentration of energy drink. The volunteers for this study were 15 male university student. 15 subjects were taken basic physical examinations such as height, weight and BMI before the experiment. Primary tests were examined of VO2max per weight of each subjects by graded exercise test using Bruce protocol. Each of five subject was divided 3 groups (CON, ECGⅠ, ECGⅡ) by matched method based on weight and VO2max per weight what gained of primary test for minimize the differences of exercise capacity and ingestion of each groups. For the secondary tests, the groups of subjects were taken their materials before and after exercise as a blind test. After the ingestion, subjects were experimented on exercise test of VO2max 80% by treadmill until the all-out. Heart rate was measured by 1minute interval, and respiratory variables were analyzed VO2, VE, VT, RR and so on by automatic respiratory analyzer. And exercise exhaustion time was determined by stopwatch. Moreover, HRV was measured after exercise and recovery 3 min. Among the intake groups, ECGⅡ was showed the longest of exercise exhaustion time more than CON group (p = .05). Result of heart rate during exercise according to intake groups, there was significant differences of each time (p < .001), however, not significant differences of each groups and group verse time (p > .05). Result of RPE during exercise according to intake groups, there was significant differences of each time (p < .001), however, not significant differences of each groups and group verse time (p > .05). In conclusion, EDGⅡ showed the significant increase of exercise exhaustion time more than CON group (p=.05) and not significant differences in HR, RPE, RER, HRV, HRR, blood pressure (p > .05). Therefore, 2.5 mg/kg(-1) ingestion of energy drink might be positive effect
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Age-related disappearance of Mayer-like heart rate waves
NASA Technical Reports Server (NTRS)
Jarisch, W. R.; Ferguson, J. J.; Shannon, R. P.; Wei, J. Y.; Goldberger, A. L.
1987-01-01
The effect of age on the principal spectral components of heart rate obtained immediately after passive upright tilt was investigated in human subjects who underwent a 60-deg tilt over 9 sec. Two groups were examined, the first of which consisting of healthy male subjects aged 22-26 years, while the second was comprised of subjects aged 65-84 years on no medication; radiograms were recorded continuously beginning just prior to tilt until 3 min posttilt. The results of spectral analysis showed that elderly subjects did not exhibit the Mayer-like heart rate waves (the 0.07-0.09 Hz oscillations) that were present in the spectra of young subjects immediately after passive upright tilt. The findings are consistent with the concept of a 'dysautonomia of aging'. It is suggested that postural stress testing with spectral analysis of heart rate fluctuations may provide a useful way of assessing physiologic vs chronologic age.
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NASA Technical Reports Server (NTRS)
Makikallio, T. H.; Seppanen, T.; Airaksinen, K. E.; Koistinen, J.; Tulppo, M. P.; Peng, C. K.; Goldberger, A. L.; Huikuri, H. V.
1997-01-01
Dynamics analysis of RR interval behavior and traditional measures of heart rate variability were compared between postinfarction patients with and without vulnerability to ventricular tachyarrhythmias in a case-control study. Short-term fractal correlation of heart rate dynamics was better than traditional measures of heart rate variability in differentiating patients with and without life-threatening arrhythmias.
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Estimating energy expenditure from heart rate in older adults: a case for calibration.
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.
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Targeting Mitochondrial Calcium Handling and Reactive Oxygen Species in Heart Failure.
Dietl, Alexander; Maack, Christoph
2017-08-01
In highly prevalent cardiac diseases, new therapeutic approaches are needed. Since the first description of oxidative stress in heart failure, reactive oxygen species (ROS) have been considered as attractive drug targets. Though clinical trials evaluating antioxidant vitamins as ROS-scavenging agents yielded neutral results in patients at cardiovascular risk, the knowledge of ROS as pathophysiological factors has considerably advanced in the past few years and led to novel treatment approaches. Here, we review recent new insights and current strategies in targeting mitochondrial calcium handling and ROS in heart failure. Mitochondria are an important ROS source, and more recently, drug development focused on targeting mitochondria (e.g. by SS-31 or MitoQ). Important advancement has also been made to decipher how the matching of energy supply and demand through calcium (Ca 2+ ) handling impacts on mitochondrial ROS production and elimination. This opens novel opportunities to ameliorate mitochondrial dysfunction in heart failure by targeting cytosolic and mitochondrial ion transporters to improve this matching process. According to this approach, highly specific substances as the preclinical CGP-37157, as well as the clinically used ranolazine and empagliflozin, provide promising results on different levels of evidence. Furthermore, the understanding of redox signalling relays, resembled by catalyst-mediated protein oxidation, is about to change former paradigms of ROS signalling. Novel methods, as redox proteomics, allow to precisely analyse key regulatory thiol switches, which may induce adaptive or maladaptive signalling. Additionally, the generation of genetically encoded probes increased the spatial and temporal resolution of ROS imaging and opened a new methodological window to subtle, formerly obscured processes. These novel insights may broaden our understanding of why previous attempts to target oxidative stress have failed, and at the same time provide us
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Gaussian Mixture Model of Heart Rate Variability
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
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Blockade of hyperpolarizing currents produces a dose-dependent effect on heart rate.
Ziyatdinova, N I; Giniatullin, R A; Svyatova, N V; Zefirov, T L
2001-03-01
Intravenous injection of ZD 7288, a new specific hyperpolarizing current blocker, dose-dependently reduces heart rate in adult rats. The autonomic nervous system modulates changes in heart rate caused by hyperpolarizing currents.
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Johansson, Benny
2008-10-01
This study explores the effects of vortex-water transpired from indoor greenery to office air, in relation to heart rate and heart rate variability during exposure to an electromagnetic field (EMF) from a visual display terminal (VDT). The study followed a randomized prospective single group cross-over design. Fifty (50) healthy volunteers, seated in any ordinary working posture in front of a VDT. Electrocardiography was measured in five 10-minute sequential tests. The VDT was turned off during the first test and switched on for the subsequent four tests. During tests 3 and 4, one of two Begonia Eliator plants, irrigated with either tap water or vortex-rotated (active) tap water during growth, was placed adjacent to the VDT. Heart rate, heart rate variability (HRV) and power spectral density (PSD) were analyzed. The heart rate was unchanged at the start of EMF exposure. The time domain measurements indicated a significant decrease in heart rate and a significant increase in HRV, accompanied by higher vagal tone in the presence, and finally in the absence, of the active plant. PSD parameters revealed significantly higher total power, as well as an increase in low frequencies (LF) and high frequencies (HF) in the condition induced by the active plant as well as after its removal. Very low frequencies (VLF) increased at EMF exposure whereas normally HF power decreased, accompanied by a rise in LF power and LF/HF ratio. HF power was higher at exposure to the active compared to the control plant. Spectral power density diagrams revealed an intensified spectral power band at frequencies of around 0.1 Hz at the condition of both plants, indicating systemic autonomic stability. The findings suggest that the parasympathetic response was associated with reduced heart rate, implicating restoration and maintenance of metabolic energy resources mediated by an involuntary adaptation to active plant-related stimuli.
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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.
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Heart rate reactivity and current post-traumatic stress disorder when data are missing.
Jeon-Slaughter, Haekyung; Tucker, Phebe; Pfefferbaum, Betty; North, Carol S; de Andrade, Bernardo Borba; Neas, Barbara
2011-08-01
This study demonstrates that auxiliary and exclusion criteria variables increase the effectiveness of missing imputation in correcting underestimation of physiologic reactivity in relation to post-traumatic stress disorder (PTSD) caused by deleting cases with missing physiologic data. This study used data from survivors of the 1995 Oklahoma City bombing and imputed missing heart rate data using auxiliary and exclusion criteria variables. Logistic regression was used to examine heart rate reactivity in relation to current PTSD. Of 113 survivors who participated in the bombing study's 7-year follow-up interview, 42 (37%) had missing data on heart rate reactivity due to exclusion criteria (medical illness or use of cardiovascular or psychotropic medications) or non-participation. Logistic regression results based on imputed heart rate data using exclusion criteria and auxiliary (the presence of any current PTSD arousal symptoms) variables showed that survivors with current bombing-related PTSD had significantly higher heart rates at baseline and recovered more slowly back to baseline heart rate during resting periods than survivors without current PTSD, while results based on complete cases failed to show significant correlations between current PTSD and heart rates at any assessment points. Suggested methods yielded an otherwise undetectable link between physiology and current PTSD. © 2011 The Authors. Psychiatry and Clinical Neurosciences © 2011 Japanese Society of Psychiatry and Neurology.
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Heart rate variability of human in hypoxic oxygen-argon environment
NASA Astrophysics Data System (ADS)
Khayrullina, Rezeda; Smoleevskiy, Alexandr; Bubeev, Yuri
Human adaptive capacity, reliability and stability in extreme environments depend primarily on the individual resistance to stresses, includes both innate and acquired components. We have conducted studies in six healthy subjects - men aged between 24 to 42 years who psychophysiological indicators acterizing the severity of stress reactions studied directly during an emergency situation, before and after it. The subjects were in a hypoxic oxygen-argon atmosphere 10 days. Cardiovascular system is one of the first to respond to stressful reaction. The method of heart rate variability (HRV) allows us to estimate balance of sympathetic and parasympathetic parts of vegetative nervous system. In the course of the baseline study it was found that resting heart rate (HR) in the examined individuals is within normal limits. During the experiment in all subjects there was a trend towards more frequent heartbeat. Each subject at one stage or another stay in a hypoxic oxygen-argon environment heart rate go beyond the group norm, but the extent and duration of these abnormalities were significantly different. Marked increase in middle heart rate during of subjects experiment, fluctuating within a wide range (from 2.3% to 29.1%). Marked increase in middle heart rate during of subjects experiment, fluctuating within a wide range (from 2.3% to 29.1%). This suggests that the ability to adapt to living in the investigated gas environment have marked individual differences. SDNN (mean square deviation of all R-R intervals) is the integral indicator of the total effect of the sinus node to the sympathetic and parasympathetic parts of vegetative nervous system, as well as indicating the higher functional reserves of the cardiovascular systems. Increase in heart rate in the majority of subject was accompanied by an increase in individual SDNN. This suggests that the parasympathetic system is able to balance the increase in activity of the sympathetic system, and functional reserves are
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The predictive value of resting heart rate following osmotherapy in brain injury: back to basics.
Hasanpour Mir, Mahsa; Yousefshahi, Fardin; Abdollahi, Mohammad; Ahmadi, Arezoo; Nadjafi, Atabak; Mojtahedzadeh, Mojtaba
2012-12-30
The importance of resting heart rate as a prognostic factor was described in several studies. An elevated heart rate is an independent risk factor for adverse cardiovascular events and total mortality in patients with coronary artery disease, chronic heart failure, and the general population. Also heart rate is elevated in the Multi Organ Dysfunction Syndrome (MODS) and the mortality due to MODS is highly correlated with inadequate sinus tachycardia.To evaluate the value of resting heart rate in predicting mortality in patients with traumatic brain injury along scoring systems like Acute Physiology and Chronic Health Evaluation(APACHE II), Sequential Organ Failure Assessment (SOFA) and Glasgow Coma Score (GCS). By analyzing data which was collected from an open labeled randomized clinical trial that compared the different means of osmotherapy (mannitol vs bolus or infusion hypertonic saline), heart rate, GCS, APACHE II and SOFA score were measured at baseline and daily for 7 days up to 60 days and the relationship between elevated heart rate and mortality during the first 7 days and 60th day were assessed. After adjustments for confounding factors, although there was no difference in mean heart rate between either groups of alive and expired patients, however, we have found a relative correlation between 60th day mortality rate and resting heart rate (P=0.07). Heart rate can be a prognostic factor for estimating mortality rate in brain injury patients along with APACHE II and SOFA scores in patients with brain injury.
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Heart rate turbulence predicts ICD-resistant mortality in ischaemic heart disease.
Marynissen, Thomas; Floré, Vincent; Heidbuchel, Hein; Nuyens, Dieter; Ector, Joris; Willems, Rik
2014-07-01
In high-risk patients, implantable cardioverter-defibrillators (ICDs) can convert the mode of death from arrhythmic to pump failure death. Therefore, we introduced the concept of 'ICD-resistant mortality' (IRM), defined as death (a) without previous appropriate ICD intervention (AI), (b) within 1 month after the first AI, or (c) within 1 year after the initial ICD implantation. Implantable cardioverter-defibrillator implantation in patients with a high risk of IRM should be avoided. Implantable cardioverter-defibrillator patients with ischaemic heart disease were included if a digitized 24 h Holter was available pre-implantation. Demographic, electrocardiographic, echocardiographic, and 24 h Holter risk factors were collected at device implantation. The primary endpoint was IRM. Cox regression analyses were used to test the association between predictors and outcome. We included 130 patients, with a mean left ventricular ejection fraction (LVEF) of 33.6 ± 10.3%. During a follow-up of 52 ± 31 months, 33 patients died. There were 21 cases of IRM. Heart rate turbulence (HRT) was the only Holter parameter associated with IRM and total mortality. A higher New York Heart Association (NYHA) class and a lower body mass index were the strongest predictors of IRM. Left ventricular ejection fraction predicted IRM on univariate analysis, and was the strongest predictor of total mortality. The only parameter that predicted AI was non-sustained ventricular tachycardia. Implantable cardioverter-defibrillator implantation based on NYHA class and LVEF leads to selection of patients with a higher risk of IRM and death. Heart rate turbulence may have added value for the identification of poor candidates for ICD therapy. Available Holter parameters seem limited in their ability to predict AI. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2013. For permissions please email: journals.permissions@oup.com.
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Chuian, O M; Biriukova, O O; Ravaieva, M Iu
2010-01-01
We studied the changes in indexes of variability of heart rate and fractal neurodynamics under conditions of controlled breathing on fluctuation frequency of a spectrum of heart rate. It is shown that the controlled breathing, which frequency corresponds to a frequency of localization of the maximum peak of capacity ofa heart rate in low-frequency is a powerful mechanism of management of heart rate and change of a functional condition of an organism as a whole.
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Gender- and age-related differences in heart rate dynamics: are women more complex than men?
NASA Technical Reports Server (NTRS)
Ryan, S. M.; Goldberger, A. L.; Pincus, S. M.; Mietus, J.; Lipsitz, L. A.
1994-01-01
OBJECTIVES. This study aimed to quantify the complex dynamics of beat-to-beat sinus rhythm heart rate fluctuations and to determine their differences as a function of gender and age. BACKGROUND. Recently, measures of heart rate variability and the nonlinear "complexity" of heart rate dynamics have been used as indicators of cardiovascular health. Because women have lower cardiovascular risk and greater longevity than men, we postulated that there are important gender-related differences in beat-to-beat heart rate dynamics. METHODS. We analyzed heart rate dynamics during 8-min segments of continuous electrocardiographic recording in healthy young (20 to 39 years old), middle-aged (40 to 64 years old) and elderly (65 to 90 years old) men (n = 40) and women (n = 27) while they performed spontaneous and metronomic (15 breaths/min) breathing. Relatively high (0.15 to 0.40 Hz) and low (0.01 to 0.15 Hz) frequency components of heart rate variability were computed using spectral analysis. The overall "complexity" of each heart rate time series was quantified by its approximate entropy, a measure of regularity derived from nonlinear dynamics ("chaos" theory). RESULTS. Mean heart rate did not differ between the age groups or genders. High frequency heart rate power and the high/low frequency power ratio decreased with age in both men and women (p < 0.05). The high/low frequency power ratio during spontaneous and metronomic breathing was greater in women than men (p < 0.05). Heart rate approximate entropy decreased with age and was higher in women than men (p < 0.05). CONCLUSIONS. High frequency heart rate spectral power (associated with parasympathetic activity) and the overall complexity of heart rate dynamics are higher in women than men. These complementary findings indicate the need to account for gender-as well as age-related differences in heart rate dynamics. Whether these gender differences are related to lower cardiovascular disease risk and greater longevity in
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Computerized system for assessing heart rate variability.
Frigy, A; Incze, A; Brânzaniuc, E; Cotoi, S
1996-01-01
The principal theoretical, methodological and clinical aspects of heart rate variability (HRV) analysis are reviewed. This method has been developed over the last 10 years as a useful noninvasive method of measuring the activity of the autonomic nervous system. The main components and the functioning of the computerized rhythm-analyzer system developed by our team are presented. The system is able to perform short-term (maximum 20 minutes) time domain HRV analysis and statistical analysis of the ventricular rate in any rhythm, particularly in atrial fibrillation. The performances of our system are demonstrated by using the graphics (RR histograms, delta RR histograms, RR scattergrams) and the statistical parameters resulted from the processing of three ECG recordings. These recordings are obtained from a normal subject, from a patient with advanced heart failure, and from a patient with atrial fibrillation.
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A PC-aided optical foetal heart rate detection system.
Oweis, Rami J; As'ad, Hala; Aldarawsheh, Amany; Al-Khdeirat, Rawan; Lwissy, Kaldoun
2014-01-01
Safe monitoring of foetal heart rate is a valuable tool for the healthy evolution and wellbeing of both foetus and mother. This paper presents a non-invasive optical technique that allows for foetal heart rate detection using a photovoltaic infrared (IR) detector placed on the mother's abdomen. The system presented here consists of a photoplethysmography (PPG) circuit, abdomen circuit and a personal computer equipped with MATLAB. A near IR beam having a wavelength of 880 nm is transmitted through the mother's abdomen and foetal tissue. The received abdominal signal that conveys information pertaining to the mother and foetal heart rate is sensed by a low noise photodetector. The PC receives the signal through the National Instrumentation Data Acquisition Card (NIDAQ). After synchronous detection of the abdominal and finger PPG signals, the designed MATLAB-based software saves, analyses and extracts information related to the foetal heart rate. Extraction is carried out using recursive least squares adaptive filtration. Measurements on eight pregnant women with gestational periods ranging from 35-39 weeks were performed using the proposed system and CTG. Results show a correlation coefficient of 0.978 and a correlation confidence interval between 88-99.6%. The t test results in a p value of 0.034, which is less than 0.05. Low power, low cost, high signal-to-noise ratio, reduction of ambient light effect and ease of use are the main characteristics of the proposed system.
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ERIC Educational Resources Information Center
Bimmel, Nicole; van IJzendoorn, Marinus H.; Bakermans-Kranenburg, Marian J.; Juffer, Femmie; De Geus, Eco J. C.
2008-01-01
The present longitudinal study examined resting heart rate and heart rate variability and reactivity to a stressful gambling task in adopted adolescents with aggressive, delinquent, or internalizing behavior problems and adopted adolescents without behavior problems (total N=151). Early-onset delinquent adolescents showed heart rate…
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Wyatt, Stephen W; Maynard, William Ryan; Risser, David R; Hakenewerth, Anne M; Williams, Melanie A; Garcia, Rebecca
2014-01-01
Diseases of the heart and malignant neoplasms (all-cancers) are the leading causes of death in the United States. The gap between the two has been closing in recent years. To assess the gap status in Texas and to establish a baseline to support evaluation efforts for the Cancer Prevention Research Institute of Texas, mortality data from 2006 to 2009 were analyzed. Immediate cause of death data in Texas for the years 2006-2009 were analyzed and rates developed by sex, race/ethnicity, and four metropolitan counties. Overall, for the years 2006-2009, the age-adjusted mortality rates (AARs) among Texas residents for both diseases of the heart and all-cancers decreased; however, during this time frame, there was greater improvement in diseases of the heart AARs as compared with all-cancers AARs. For the four large metropolitan counties of Bexar, Dallas, Harris, and Travis, data were analyzed by sex and race/ethnicity, and 11 of the 12 largest percent mortality rate decreases were for diseases of the heart. Age-adjusted mortality rates among Texas residents from diseases of the heart are showing improvement as compared with the rates for all-cancers.
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Cardiovascular Fitness and Maximal Heart Rate Differences Among Three Ethnic Groups.
ERIC Educational Resources Information Center
Farrell, S. W.
1988-01-01
Examination of differences in maximal heart rate and treadmill time among three ethnic groups revealed no significant age-adjusted differences among white, black, and Mexican-American males, and suggested that black females' lower maximal heart rate may be explained by their lower cardiovascular fitness level when compared to those of other…
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Association of educational status with heart rate recovery: a population-based propensity analysis.
Shishehbor, Mehdi H; Baker, David W; Blackstone, Eugene H; Lauer, Michael S
2002-12-01
An abnormally attenuated heart rate recovery after exercise is a predictor of mortality that is thought to reflect decreased parasympathetic activity. Lower educational level may be associated with automatic imbalance. We sought to assess the association of educational level with heart rate recovery. Among 5246 healthy adults from a population-based cohort who underwent exercise testing, 874 (17%) did not graduate from high school, 1823 (35%) completed high school, and 2549 (49%) attended at least some college. An abnormal heart rate recovery was defined as a difference of heart rate and that after 2 minutes of recovery. Propensity scores were used to account for differences by educational status. An abnormal heart rate recovery was more common among adults who did not graduate from high school compared with those who attended at least some college (50% [440/874] vs. 28% [701/2549]; odds ratio [OR]: 2.7; 95% confidence interval [CI]: 2.3 to 3.1; P <0.001). After using propensity scores, lower educational status remained associated with an abnormal heart rate recovery (OR = 1.9; 95% CI: 1.6 to 2.4; P <0.001). During 12-years of follow-up, there were 327 deaths. Poor educational status was associated with greater mortality (9% [80/874] vs. 6% [247/4372]; unadjusted hazard ratio [HR] = 1.9; 95% CI: 1.4 to 2.5; P <0.001). However, after accounting for age, sex, and heart rate recovery, educational status was a weaker predictor (HR = 1.3; 95% CI: 1.0 to 1.7). Educational status is independently associated with an abnormal heart rate recovery.
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Baek, Hyun Jae; Shin, JaeWook; Jin, Gunwoo; Cho, Jaegeol
2017-10-24
Photoplethysmographic signals are useful for heart rate variability analysis in practical ambulatory applications. While reducing the sampling rate of signals is an important consideration for modern wearable devices that enable 24/7 continuous monitoring, there have not been many studies that have investigated how to compensate the low timing resolution of low-sampling-rate signals for accurate heart rate variability analysis. In this study, we utilized the parabola approximation method and measured it against the conventional cubic spline interpolation method for the time, frequency, and nonlinear domain variables of heart rate variability. For each parameter, the intra-class correlation, standard error of measurement, Bland-Altman 95% limits of agreement and root mean squared relative error were presented. Also, elapsed time taken to compute each interpolation algorithm was investigated. The results indicated that parabola approximation is a simple, fast, and accurate algorithm-based method for compensating the low timing resolution of pulse beat intervals. In addition, the method showed comparable performance with the conventional cubic spline interpolation method. Even though the absolute value of the heart rate variability variables calculated using a signal sampled at 20 Hz were not exactly matched with those calculated using a reference signal sampled at 250 Hz, the parabola approximation method remains a good interpolation method for assessing trends in HRV measurements for low-power wearable applications.
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Heart rate variability as determinism with jump stochastic parameters.
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.
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Music structure determines heart rate variability of singers
Vickhoff, Björn; Malmgren, Helge; Åström, Rickard; Nyberg, Gunnar; Ekström, Seth-Reino; Engwall, Mathias; Snygg, Johan; Nilsson, Michael; Jörnsten, Rebecka
2013-01-01
Choir singing is known to promote wellbeing. One reason for this may be that singing demands a slower than normal respiration, which may in turn affect heart activity. Coupling of heart rate variability (HRV) to respiration is called Respiratory sinus arrhythmia (RSA). This coupling has a subjective as well as a biologically soothing effect, and it is beneficial for cardiovascular function. RSA is seen to be more marked during slow-paced breathing and at lower respiration rates (0.1 Hz and below). In this study, we investigate how singing, which is a form of guided breathing, affects HRV and RSA. The study comprises a group of healthy 18 year olds of mixed gender. The subjects are asked to; (1) hum a single tone and breathe whenever they need to; (2) sing a hymn with free, unguided breathing; and (3) sing a slow mantra and breathe solely between phrases. Heart rate (HR) is measured continuously during the study. The study design makes it possible to compare above three levels of song structure. In a separate case study, we examine five individuals performing singing tasks (1–3). We collect data with more advanced equipment, simultaneously recording HR, respiration, skin conductance and finger temperature. We show how song structure, respiration and HR are connected. Unison singing of regular song structures makes the hearts of the singers accelerate and decelerate simultaneously. Implications concerning the effect on wellbeing and health are discussed as well as the question how this inner entrainment may affect perception and behavior. PMID:23847555
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Accuracy of pulse oximeters in estimating heart rate at rest and during exercise.
Iyriboz, Y; Powers, S; Morrow, J; Ayers, D; Landry, G
1991-01-01
Pulse oximeters are being widely used for non-invasive, simultaneous assessment of haemoglobin oxygen saturation. They are reliable, accurate, relatively inexpensive and portable. Pulse oximeters are often used for estimating heart rate at rest and during exercise. However, at present the data available to validate their use as heart rate monitors are not sufficient. We evaluated the accuracy of two oximeters (Radiometer, ear and finger probe; Ohmeda 3700, ear probe) in monitoring heart rate during incremental exercise by comparing the pulse oximeters with simultaneous ECG readings. Data were collected on eight men (713 heart rate readings) during graded cycle ergometer and treadmill exercise to volitional fatigue. Analysis by linear regression revealed that general oximeter readings significantly correlated with those of ECG (r = 0.91, P less than 0.0001). However, comparison of heart rate at each level of work showed that oximeter readings significantly (P less than 0.05) under-estimated rates above 155 beats/min. These results indicate that the use of pulse oximeters as heart rate monitors during strenuous exercise is questionable. This inaccuracy may well originate from the instability of the probes, sweating, other artefacts during exercise, and measurement of different components in the cardiovascular cycle. PMID:1777787
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Mulder, Bart A; Damman, Kevin; Van Veldhuisen, Dirk J; Van Gelder, Isabelle C; Rienstra, Michiel
2017-09-01
Heart rate has been associated with prognosis in patients with heart failure with reduced ejection fraction (HFREF) and sinus rhythm; whether this also holds true in patients with atrial fibrillation (AF) is unknown. To evaluate cardiac rhythm and baseline heart rate and the influence of outcome in patients with HFREF enrolled in the Cardiac Insufficiency Bisoprolol Study II. In total, 2539 patients were stratified according to their baseline heart rhythm (AF or sinus rhythm) and into quartiles of heart rate (≤70 bpm, 71-78 bpm, 79-90 bpm, and >90 bpm). The primary outcome was all-cause mortality. Mean follow-up was 1.3 years. Mean age was 61 years, mean left ventricular ejection fraction was 28%, and 80% were male. A total of 521 (21%) patients had AF at baseline. The risk associated with all-cause mortality for each 5 bpm increase in heart rate in patients with sinus rhythm (hazard ratio [HR]: 1.06, 95% confidence interval [CI]: 1.01-1.11, P = 0.012) was significantly different from those with AF (HR: 1.00, 95% CI: 0.94-1.07, P = 0.90, P for interaction = 0.041). The risk associated with higher heart rate in sinus rhythm was primarily attributable to excess risk in the highest quartile (HR: 1.64, 95% CI: 1.18-2.30, P = 0.003). Allocation to bisoprolol did not modify the interaction between heart rate, rhythm and outcome. In HFREF patients with AF, a higher heart rate is not associated with increased event rates in contrast to HFREF patients with sinus rhythm. © 2017 Wiley Periodicals, Inc.
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Meyer, Markus; Rambod, Mehdi; LeWinter, Martin
2018-07-01
Epidemiological studies have demonstrated that high resting heart rates are associated with increased mortality. Clinical studies in patients with heart failure and reduced ejection fraction have shown that heart rate lowering with beta-blockers and ivabradine improves survival. It is therefore often assumed that heart rate lowering is beneficial in other patients as well. Here, we critically appraise the effects of pharmacological heart rate lowering in patients with both normal and reduced ejection fraction with an emphasis on the effects of pharmacological heart rate lowering in hypertension and heart failure. Emerging evidence from recent clinical trials and meta-analyses suggest that pharmacological heart rate lowering is not beneficial in patients with a normal or preserved ejection fraction. This has just begun to be reflected in some but not all guideline recommendations. The detrimental effects of pharmacological heart rate lowering are due to an increase in central blood pressures, higher left ventricular systolic and diastolic pressures, and increased ventricular wall stress. Therefore, we propose that heart rate lowering per se reproduces the hemodynamic effects of diastolic dysfunction and imposes an increased arterial load on the left ventricle, which combine to increase the risk of heart failure and atrial fibrillation. Pharmacologic heart rate lowering is clearly beneficial in patients with a dilated cardiomyopathy but not in patients with normal chamber dimensions and normal systolic function. These conflicting effects can be explained based on a model that considers the hemodynamic and ventricular structural effects of heart rate changes.
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The predictive value of resting heart rate following osmotherapy in brain injury: back to basics
2012-01-01
Background The importance of resting heart rate as a prognostic factor was described in several studies. An elevated heart rate is an independent risk factor for adverse cardiovascular events and total mortality in patients with coronary artery disease, chronic heart failure, and the general population. Also heart rate is elevated in the Multi Organ Dysfunction Syndrome (MODS) and the mortality due to MODS is highly correlated with inadequate sinus tachycardia. To evaluate the value of resting heart rate in predicting mortality in patients with traumatic brain injury along scoring systems like Acute Physiology and Chronic Health Evaluation(APACHE II), Sequential Organ Failure Assessment (SOFA) and Glasgow Coma Score (GCS). Method By analyzing data which was collected from an open labeled randomized clinical trial that compared the different means of osmotherapy (mannitol vs bolus or infusion hypertonic saline), heart rate, GCS, APACHE II and SOFA score were measured at baseline and daily for 7 days up to 60 days and the relationship between elevated heart rate and mortality during the first 7 days and 60th day were assessed. Results After adjustments for confounding factors, although there was no difference in mean heart rate between either groups of alive and expired patients, however, we have found a relative correlation between 60th day mortality rate and resting heart rate (P=0.07). Conclusion Heart rate can be a prognostic factor for estimating mortality rate in brain injury patients along with APACHE II and SOFA scores in patients with brain injury. PMID:23351393
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NASA Technical Reports Server (NTRS)
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.
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Prasada, Sameer; Oswalt, Cameron; Yeboah, Phyllis; Saylor, Georgia; Bowden, Donald; Yeboah, Joseph
2018-01-15
To assess the association of resting heart rate with all-cause and cardiovascular disease (CVD) mortality in the Diabetes Heart Study (DHS). Out of a total of 1443 participants recruited into the DHS, 1315 participants with type 2 diabetes who were free of atrial fibrillation and supraventricular tachycardia during the baseline exam were included in this analysis. Heart rate was collected from baseline resting electrocardiogram and mortality (all-cause and CVD) was obtained from state and national death registry. Kaplan-Meier (K-M) and Cox proportional hazard analyses were used to assess the association. The mean age, body mass index (BMI) and systolic blood pressure (SBP) of the cohort were 61.4 ± 9.2 years, 32.0 ± 6.6 kg/m 2 , and 139.4 ± 19.4 mmHg respectively. Fifty-six percent were females, 85% were whites, 15% were blacks, 18% were smokers. The mean ± SD heart rate was 69.8 (11.9) beats per minute (bpm). After a median follow-up time of 8.5 years (maximum follow-up time is 14.0 years), 258 participants were deceased. In K-M analysis, participants with heart rate above the median had a significantly higher event rate compared with those below the median (log-rank P = 0.0223). A one standard deviation increase in heart rate was associated with all-cause mortality in unadjusted (hazard ratio 1.16, 95%CI: 1.03-1.31) and adjusted (hazard ratio 1.20, 95%CI: 1.05-1.37) models. Similar results were obtained with CVD mortality as the outcome of interest. Heart rate is an independent predictor of all-cause mortality in this population with type 2 diabetes. In this study, a 1-SD increase in heart rate was associated with a 20% increase in risk suggesting that additional prognostic information may be gleaned from this ubiquitously collected vital sign.
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Relationship between heart rate and quiescent interval of the cardiac cycle in children using MRI.
Zhang, Wei; Bogale, Saivivek; Golriz, Farahnaz; Krishnamurthy, Rajesh
2017-11-01
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.
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Waring, W S; Rhee, J Y; Bateman, D N; Leggett, G E; Jamie, H
2008-11-01
Antidepressant overdose may be associated with significant cardiotoxicity, and recent data have shown that acute toxic effects are associated with impaired heart rate variability. This study was designed to examine the feasibility of non-invasive heart rate variability recording in patients that present to hospital after deliberate antidepressant ingestion. This was a prospective study of 72 consecutive patients attending the Emergency Department after deliberate antidepressant overdose and 72 age-matched patients that ingested paracetamol, as a control group. Single time-point continuous electrocardiographic recordings were used to allow spectral analyses of heart rate variability determined in low-frequency (LF) and high-frequency (HF) domains. The LF:HF ratio was used to represent overall sympathovagal cardiac activity. Antidepressant overdose was associated with reduced overall heart rate variability: 1329 vs. 2018 ms(2) (P = 0.0239 by Mann-Whitney test). Variability in the LF domain was higher (64.8 vs. 49.8, P = 0.0006), whereas that in the HF domain was lower (24.3 vs. 36.4, P = 0.0001), and the LF:HF ratio was higher in the antidepressant group (2.4 vs. 1.2, P = 0.0003). Antidepressant overdose is associated with impaired heart rate variability in a pattern consistent with excess cardiac sympathetic activity. Further work is required to establish the significance of these findings and to explore whether the impairment of heart rate variability may be used to predict the development of arrhythmia in this patient group.
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Carvalho, Vitor Oliveira; Guimarães, Guilherme Veiga; Bocchi, Edimar Alcides
2008-01-01
BACKGROUND The relationship between the percentage of oxygen consumption reserve and percentage of heart rate reserve in heart failure patients either on non-optimized or off beta-blocker therapy is known to be unreliable. The aim of this study was to evaluate the relationship between the percentage of oxygen consumption reserve and percentage of heart rate reserve in heart failure patients receiving optimized and non-optimized beta-blocker treatment during a treadmill cardiopulmonary exercise test. METHODS A total of 27 sedentary heart failure patients (86% male, 50±12 years) on optimized beta-blocker therapy with a left ventricle ejection fraction of 33±8% and 35 sedentary non-optimized heart failure patients (75% male, 47±10 years) with a left ventricle ejection fraction of 30±10% underwent the treadmill cardiopulmonary exercise test (Naughton protocol). Resting and peak effort values of both the percentage of oxygen consumption reserve and percentage of heart rate reserve were, by definition, 0 and 100, respectively. RESULTS The heart rate slope for the non-optimized group was derived from the points 0.949±0.088 (0 intercept) and 1.055±0.128 (1 intercept), p<0.0001. The heart rate slope for the optimized group was derived from the points 1.026±0.108 (0 intercept) and 1.012±0.108 (1 intercept), p=0.47. Regression linear plots for the heart rate slope for each patient in the non-optimized and optimized groups revealed a slope of 0.986 (almost perfect) for the optimized group, but the regression analysis for the non-optimized group was 0.030 (far from perfect, which occurs at 1). CONCLUSION The relationship between the percentage of oxygen consumption reserve and percentage of heart rate reserve in patients on optimized beta-blocker therapy was reliable, but this relationship was unreliable in non-optimized heart failure patients. PMID:19060991
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Small-volume amnioinfusion: a potential stimulus of intrapartum fetal heart rate accelerations.
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.
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Aerobic Exercise during Pregnancy and Presence of Fetal-Maternal Heart Rate Synchronization
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
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Aerobic exercise during pregnancy and presence of fetal-maternal heart rate synchronization.
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.
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Heart Rate and Energy Expenditure in Division I Field Hockey Players During Competitive Play.
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.
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Optimal Body Temperature in Transitional ELBW Infants Using Heart Rate and Temperature as Indicators
Knobel, Robin B.; Holditch-Davis, Diane; Schwartz, Todd A.
2013-01-01
Extremely low birth weight (ELBW) infants are vulnerable to cold stress after birth. Therefore, caregivers need to control body temperature optimally to minimize energy expenditure. Objective We explored body temperature in relationship to heart rate in ELBW infants during their first 12 hours to help identify the ideal set point for incubator control of body temperature. Design Within subject, multiple-case design. Setting A tertiary NICU in North Carolina. Participants 10 infants, born less than 29 weeks gestation and weighing 400-1000 grams. Methods Heart rate and abdominal body temperature were measured at 1-minute intervals for 12 hours. Heart rates were considered normal if they were between the 25th and 75th percentile for each infant. Results Abdominal temperatures were low throughout the 12-hour study period (mean 35.17° C-36.68° C). Seven of ten infants had significant correlations between abdominal temperature and heart rate. Heart rates above the 75th percentile were associated with low and high abdominal temperatures; heart rates less than the 25th percentile were associated with very low abdominal temperatures. The extent to which abdominal temperature was abnormally low was related the extent to which the heart rate trended away from normal in six of the ten infants. Optimal temperature control point that maximized normal heart rate observations for each infant was between 36.8° C and 37° C. Conclusions Hypothermia was associated with abnormal heart rates in transitional ELBW infants. We suggest nurses set incubator servo between 36.8° C and 36.9° C to optimally control body temperature for ELBW infants. PMID:20409098
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Bluetooth(Registered Trademark) Heart Rate Monitors for Spaceflight
NASA Technical Reports Server (NTRS)
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
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[Detection of Heart Rate of Fetal ECG Based on STFT and BSS].
Wang, Xu; Cai, Kun
2016-01-01
Changes in heart rate of fetal is function regulating performance of the circulatory system and the central nervous system, it is significant to detect heart rate of fetus in perinatal fetal. This paper puts forward the fetal heart rate detection method based on short time Fourier transform and blind source separation. First of all, the mixed ECG signal was preprocessed, and then the wavelet transform technique was used to separate the fetal ECG signal with noise from mixed ECG signal, after that, the short-time Fourier transform and the blind separation were carried on it, and then calculated the correlation coefficient of it, Finally, An independent component that it has strongest correlation with the original signal was selected to make FECG peak detection and calculated the fetal instantaneous heart rate. The experimental results show that the method can improve the detection rate of the FECG peak (R), and it has high accuracy in fixing peak(R) location in the case of low signal-noise ratio.
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Dural, Muhammet; Kabakcı, Giray; Cınar, Neşe; Erbaş, Tomris; Canpolat, Uğur; Gürses, Kadri Murat; Tokgözoğlu, Lale; Oto, Ali; Kaya, Ergün Barış; Yorgun, Hikmet; Sahiner, Levent; Dağdelen, Selçuk; Aytemir, Kudret
2014-04-01
Cardiovascular complications are the most common causes of morbidity and mortality in acromegaly. However, there is little data regarding cardiac autonomic functions in these patients. Herein, we aimed to investigate several parameters of cardiac autonomic functions in patients with acromegaly compared to healthy subjects. We enrolled 20 newly diagnosed acromegalic patients (55% female, age:45.7 ± 12.6 years) and 32 age- and gender-matched healthy subjects. All participants underwent 24 h Holter recording. Heart rate recovery (HRR) indices were calculated by subtracting 1st, 2nd and 3rd minute heart rates from maximal heart rate. All patients underwent heart rate variability (HRV) and QT dynamicity analysis. Baseline characteristics were similar except diabetes mellitus and hypertension among groups. Mean HRR1 (29.2 ± 12.3 vs 42.6 ± 6.5, p = 0.001), HRR2 (43.5 ± 15.6 vs 61.1 ± 10.8, p = 0.001) and HRR3 (46.4 ± 16.2 vs 65.8 ± 9.8, p = 0.001) values were significantly higher in control group. HRV parameters as, SDNN [standard deviation of all NN intervals] (p = 0.001), SDANN [SD of the 5 min mean RR intervals] (p = 0.001), RMSSD [root square of successive differences in RR interval] (p = 0.001), PNN50 [proportion of differences in successive NN intervals >50 ms] (p = 0.001) and high-frequency [HF] (p = 0.001) were significantly decreased in patients with acromegaly; but low frequency [LF] (p = 0.046) and LF/HF (p = 0.001) were significantly higher in acromegaly patients. QTec (p = 0.009), QTac/RR slope (p = 0.017) and QTec/RR slope (p = 0.01) were significantly higher in patients with acromegaly. Additionally, there were significant negative correlation of disease duration with HRR2, HRR3, SDNN, PNN50, RMSSD, variability index. Our study results suggest that cardiac autonomic functions are impaired in patients with acromegaly. Further large scale studies are needed to exhibit the prognostic significance of impaired autonomic functions in patients with
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Heart rate variability based on risk stratification for type 2 diabetes mellitus.
Silva-E-Oliveira, Julia; Amélio, Pâmela Marina; Abranches, Isabela Lopes Laguardia; Damasceno, Dênis Derly; Furtado, Fabianne
2017-01-01
To evaluate heart rate variability among adults with different risk levels for type 2 diabetes mellitus. The risk for type 2 diabetes mellitus was assessed in 130 participants (89 females) based on the questionnaire Finnish Diabetes Risk Score and was classified as low risk (n=26), slightly elevated risk (n=41), moderate risk (n=27) and high risk (n=32). To measure heart rate variability, a heart-rate monitor Polar S810i® was employed to obtain RR series for each individual, at rest, for 5 minutes, followed by analysis of linear and nonlinear indexes. The groups at higher risk of type 2 diabetes mellitus had significantly lower linear and nonlinear heart rate variability indexes. The individuals at high risk for type 2 diabetes mellitus have lower heart rate variability. Avaliar a variabilidade da frequência cardíaca em adultos com diferentes níveis de risco para diabetes mellitus tipo 2. O grau de risco para diabetes mellitus tipo 2 de 130 participantes (41 homens) foi avaliado pelo questionário Finnish Diabetes Risk Score. Os participantes foram classificados em baixo risco (n=26), risco levemente elevado (n=41), risco moderado (n=27) e alto risco (n=32). Para medir a variabilidade da frequência cardíaca, utilizou-se o frequencímetro Polar S810i® para obter séries de intervalo RR para cada indivíduo, em repouso, durante 5 minutos; posteriormente, realizou-se análise por meio de índices lineares e não-lineares. O grupo com maior risco para diabetes mellitus tipo 2 teve uma diminuição significante nos índices lineares e não-lineares da variabilidade da frequência cardíaca. Os resultados apontam que indivíduos com risco alto para diabetes mellitus tipo 2 tem menor variabilidade da frequência cardíaca. To evaluate heart rate variability among adults with different risk levels for type 2 diabetes mellitus. The risk for type 2 diabetes mellitus was assessed in 130 participants (89 females) based on the questionnaire Finnish Diabetes Risk Score
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Klein, Franziska J; Bell, Stephen; Runte, K Elisabeth; Lobel, Robert; Ashikaga, Takamuru; Lerman, Lilach O; LeWinter, Martin M; Meyer, Markus
2016-10-01
Lowering the heart rate is considered to be beneficial in heart failure (HF) with reduced ejection fraction (HFrEF). In a dilated left ventricle (LV), pharmacological heart rate lowering is associated with a reduction in LV chamber size. In patients with HFrEF, this structural change is associated with better survival. HF with preserved ejection fraction (HFpEF) is increasingly prevalent but, so far, without any evidence-based treatment. HFpEF is typically associated with LV concentric remodeling and hypertrophy. The effects of heart rate on this structural phenotype are not known. Analogous with the benefits of a low heart rate on a dilated heart, we hypothesized that increased heart rates could lead to potentially beneficial remodeling of a concentrically hypertrophied LV. This was explored in an established porcine model of concentric LV hypertrophy and fibrosis. Our results suggest that a moderate increase in heart rate can be used to reduce wall thickness, normalize LV chamber volumes, decrease myocardial fibrosis, and improve LV compliance. Our results also indicate that the effects of heart rate can be titrated, are reversible, and do not induce HF. These findings may provide the rationale for a novel therapeutic approach for HFpEF and its antecedent disease substrate. Copyright © 2016 the American Physiological Society.
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Heart rate variability in normal-weight patients with polycystic ovary syndrome.
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.
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Cygankiewicz, Iwona; Zareba, Wojciech
2013-01-01
Heart rate variability (HRV) provides indirect insight into autonomic nervous system tone, and has a well-established role as a marker of cardiovascular risk. Recent decades brought an increasing interest in HRV assessment as a diagnostic tool in detection of autonomic impairment, and prediction of prognosis in several neurological disorders. Both bedside analysis of simple markers of HRV, as well as more sophisticated HRV analyses including time, frequency domain and nonlinear analysis have been proven to detect early autonomic involvement in several neurological disorders. Furthermore, altered HRV parameters were shown to be related with cardiovascular risk, including sudden cardiac risk, in patients with neurological diseases. This chapter aims to review clinical and prognostic application of HRV analysis in diabetes, stroke, multiple sclerosis, muscular dystrophies, Parkinson's disease and epilepsy. © 2013 Elsevier B.V. All rights reserved.
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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.
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Ambulatory blood pressure and heart rate during shuttle flight, entry and landing
NASA Technical Reports Server (NTRS)
Thornton, W.; Moore, T. P.; Uri, J.
1993-01-01
Ambulatory blood pressures (BP) and heart rates (HR) were recorded on a series of early Shuttle flights during preflight and pre-entry, entry, landing and egress. There were no significant differences between flight and preflight values during routine activity. Systolic blood pressure was slightly elevated in the deorbit period and systolic and diastolic blood pressure and heart rates were all elevated with onset of gravitoinertial loads and remained so through egress. Two of seven subjects had orthostatic problems in egress but their data did not show significant differences from others except in heart rate. Comparison of this data to that from recent studies show even larger increase in HR/BP values during current deorbit and entry phases which is consistent with increased heat and weight loads imposed by added survival gear. Both value and limitations of ambulatory heart rate/blood pressure data in this situation are demonstrated.
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Systolic time interval v heart rate regression equations using atropine: reproducibility studies.
Kelman, A W; Sumner, D J; Whiting, B
1981-01-01
1. Systolic time intervals (STI) were recorded in six normal male subjects over a period of 3 weeks. On one day per week, each subject received incremental doses of atropine intravenously to increase heart rate, allowing the determination of individual STI v HR regression equations. On the other days STI were recorded with the subjects resting, in the supine position. 2. There were highly significant regression relationships between heart rate and both LVET and QS2, but not between heart rate and PEP. 3. The regression relationships showed little intra-subject variability, but a large degree of inter-subject variability: they proved adequate to correct the STI for the daily fluctuations in heart rate. 4. Administration of small doses of atropine intravenously provides a satisfactory and convenient method of deriving individual STI v HR regression equations which can be applied over a period of weeks. PMID:7248136
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Systolic time interval v heart rate regression equations using atropine: reproducibility studies.
Kelman, A W; Sumner, D J; Whiting, B
1981-07-01
1. Systolic time intervals (STI) were recorded in six normal male subjects over a period of 3 weeks. On one day per week, each subject received incremental doses of atropine intravenously to increase heart rate, allowing the determination of individual STI v HR regression equations. On the other days STI were recorded with the subjects resting, in the supine position. 2. There were highly significant regression relationships between heart rate and both LVET and QS2, but not between heart rate and PEP. 3. The regression relationships showed little intra-subject variability, but a large degree of inter-subject variability: they proved adequate to correct the STI for the daily fluctuations in heart rate. 4. Administration of small doses of atropine intravenously provides a satisfactory and convenient method of deriving individual STI v HR regression equations which can be applied over a period of weeks.
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Kang, Seol-Jung; Ha, Gi-Chul; Ko, Kwang-Jun
2017-06-01
The present study aimed to investigate the association between metabolic syndrome and cardiorespiratory fitness according to resting heart rate of Korean male adults. A total of 11,876 male adults aged 20-65 years who underwent health examinations from 2010 to 2015 at a National Fitness Centre in South Korea were included. Subjects' resting heart rate, cardiorespiratory fitness (VO 2 max), and metabolic syndrome parameters were collected. The subjects were divided into 5 categories (<60 bpm, 60-69 bpm, 70-79 bpm, 80-89 bpm, and ≥90 bpm) of resting heart rate for further analysis. We found that elevated resting heart rate was positively associated with body mass index, systolic blood pressure, diastolic blood pressure, triglycerides, and fasting blood glucose levels ( p < 0.001, respectively); in contrast, elevated resting heart rate was inversely associated with VO 2 max ( p < 0.001). When resting heart rate of subjects was categorized into quintiles and analysed, the results showed that the relative risk of metabolic syndrome was 1.53-fold higher (95% CI, 1.34 to 1.82) in the range of 60-69 beats per minute (bpm), 2.08-fold higher (95% CI, 1.77 to 2.45) in the range of 70-79 bpm, 2.28-fold higher (95% CI, 1.73 to 3.00) in the range of 80-89 bpm, and 2.61-fold higher (95% CI, 1.62 to 4.20) in the range of ≥90 bpm, compared to those <60 bpm; this indicated that as resting heart rate increased, the relative risk of metabolic syndrome also increased. Resting heart rate of male adults was found to be associated with cardiorespiratory fitness; the risk factors for metabolic syndrome and relative risk of metabolic syndrome increased as resting heart rate increased.
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Hwang, Jing-Shiang; Nadziejko, Christine; Chen, Lung Chi
2005-04-01
Normal mice (C57) and mice prone to develop atherosclerosis (ApoE-/-) were implanted with electrocardiograph (EKG), core body temperature, and motion transmitters were exposed daily for 6 h to Tuxedo, NY, concentrated ambient particles (CAPs) for 5 day/wk during the spring and summer of 2003. The series of 5-min EKG monitoring and body-temperature measurements were obtained for each animal in the CAPs and filtered air sham exposure groups. Our hypothesis was that chronic exposure could cause cumulative health effects. We used our recently developed nonparametric method to estimate the daily time periods that mean heart rates (HR), body temperature, and physical activity differed significantly between the CAPs and sham exposed group. CAPs exposure most affected heart rate between 1:30 a.m. and 4:30 a.m. With the response variables being the average heart rate, body temperature, and physical activity, we adopted a two-stage modeling approach to obtain the estimates of chronic and acute effects on the changes of these three response variables. In the first stage, a time-varying model estimated daily crude effects. In the second stage, the true means of the estimated crude effects were modeled with a polynominal function of time for chronic effects, a linear term of daily CAPs exposure concentrations for acute effects, and a random component for unknown noise. A Bayesian framework combined these two stages. There were significant decreasing patterns of HR, body temperature, and physical activity for the ApoE-/- mice over the 5 mo of CAPs exposure, with smaller and nonsignificant changes for the C57 mice. The chronic effect changes of the three response variables for ApoE-/- mice were maximal in the last few weeks. There was also a significant relationship between CAPs exposure concentration and short-term changes of heart rate in ApoE-/- mice during exposure. Response variables were also defined for examining fluctuations of 5-min heart rates within long (i.e., 3-6 h
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Music close to one's heart: heart rate variability with music, diagnostic with e-bra and smartphone
NASA Astrophysics Data System (ADS)
Hegde, Shantala; Kumar, Prashanth S.; Rai, Pratyush; Mathur, Gyanesh N.; Varadan, Vijay K.
2012-04-01
Music is a powerful elicitor of emotions. Emotions evoked by music, through autonomic correlates have been shown to cause significant modulation of parameters like heart rate and blood pressure. Consequently, Heart Rate Variability (HRV) analysis can be a powerful tool to explore evidence based therapeutic functions of music and conduct empirical studies on effect of musical emotion on heart function. However, there are limitations with current studies. HRV analysis has produced variable results to different emotions evoked via music, owing to variability in the methodology and the nature of music chosen. Therefore, a pragmatic understanding of HRV correlates of musical emotion in individuals listening to specifically chosen music whilst carrying out day to day routine activities is needed. In the present study, we aim to study HRV as a single case study, using an e-bra with nano-sensors to record heart rate in real time. The e-bra developed previously, has several salient features that make it conducive for this study- fully integrated garment, dry electrodes for easy use and unrestricted mobility. The study considers two experimental conditions:- First, HRV will be recorded when there is no music in the background and second, when music chosen by the researcher and by the subject is playing in the background.
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Van Dyke, Miriam E; Komro, Kelli A; Shah, Monica P; Livingston, Melvin D; Kramer, Michael R
2018-07-01
Despite substantial declines since the 1960's, heart disease remains the leading cause of death in the United States (US) and geographic disparities in heart disease mortality have grown. State-level socioeconomic factors might be important contributors to geographic differences in heart disease mortality. This study examined the association between state-level minimum wage increases above the federal minimum wage and heart disease death rates from 1980 to 2015 among 'working age' individuals aged 35-64 years in the US. Annual, inflation-adjusted state and federal minimum wage data were extracted from legal databases and annual state-level heart disease death rates were obtained from CDC Wonder. Although most minimum wage and health studies to date use conventional regression models, we employed marginal structural models to account for possible time-varying confounding. Quasi-experimental, marginal structural models accounting for state, year, and state × year fixed effects estimated the association between increases in the state-level minimum wage above the federal minimum wage and heart disease death rates. In models of 'working age' adults (35-64 years old), a $1 increase in the state-level minimum wage above the federal minimum wage was on average associated with ~6 fewer heart disease deaths per 100,000 (95% CI: -10.4, -1.99), or a state-level heart disease death rate that was 3.5% lower per year. In contrast, for older adults (65+ years old) a $1 increase was on average associated with a 1.1% lower state-level heart disease death rate per year (b = -28.9 per 100,000, 95% CI: -71.1, 13.3). State-level economic policies are important targets for population health research. Copyright © 2018 Elsevier Inc. All rights reserved.
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Remote Measurements of Heart and Respiration Rates for Telemedicine
Qian, Yi; Tsien, Joe Z.
2013-01-01
Non-contact and low-cost measurements of heart and respiration rates are highly desirable for telemedicine. Here, we describe a novel technique to extract blood volume pulse and respiratory wave from a single channel images captured by a video camera for both day and night conditions. The principle of our technique is to uncover the temporal dynamics of heart beat and breathing rate through delay-coordinate transformation and independent component analysis-based deconstruction of the single channel images. Our method further achieves robust elimination of false positives via applying ratio-variation probability distributions filtering approaches. Moreover, it enables a much needed low-cost means for preventing sudden infant death syndrome in new born infants and detecting stroke and heart attack in elderly population in home environments. This noncontact-based method can also be applied to a variety of animal model organisms for biomedical research. PMID:24115996
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[Current status and recommendations for intrapartum monitoring of fetal heart rate].
Měchurová, A; Velebil, P; Hruban, L; Janků, P
2016-04-01
Monitoring of fetal heart rate is one of the basic components of obstetrical care, in which the cardiotocography remains the gold standard and screening method in early diagnosis of fetal hypoxia, even after introduction of other selective methods of intrauterine monitoring of fetal well-being. The review article is divided into several parts: pathophysiology of fetal oxygenation, fetal heart rate and changes of fetal hemodynamics, and rules for fetal heart rate auscultation. The main principles of cardiotocographic monitoring and evaluation of ante- and intrapartrum recordings according to the FIGO criteria from 1986 and evaluation of intrapartum recordings according to the 2015 FIGO recommendations are mentioned. At the end a comparative table of 1986 FIGO and 2015 FIGO criteria is presented. Review.
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Transfer entropy analysis of maternal and fetal heart rate coupling.
Marzbanrad, Faezeh; Kimura, Yoshitaka; Endo, Miyuki; Palaniswami, Marimuthu; Khandoker, Ahsan H
2015-01-01
Although evidence of the short term relationship between maternal and fetal heart rates has been found in previous model-based studies, knowledge about the mechanism and patterns of the coupling during gestation is still limited. In this study, a model-free method based on Transfer Entropy (TE) was applied to quantify the maternal-fetal heart rate couplings in both directions. Furthermore, analysis of the lag at which TE was maximum and its changes throughout gestation, provided more information about the mechanism of coupling and its latency. Experimental results based on fetal electrocardiograms (fECGs) and maternal ECG showed the evidence of coupling for 62 out of 65 healthy mothers and fetuses in each direction, by statistically validating against the surrogate pairs. The fetuses were divided into three gestational age groups: early (16-25 weeks), mid (26-31 weeks) and late (32-41 weeks) gestation. The maximum TE from maternal to fetal heart rate significantly increased from early to mid gestation, while the coupling delay on both directions decreased significantly from mid to late gestation. These changes occur concomitant with the maturation of the fetal sensory and autonomic nervous systems with advancing gestational age. In conclusion, the application of TE with delays revealed detailed information about the changes in fetal-maternal heart rate coupling strength and latency throughout gestation, which could provide novel clinical markers of fetal development and well-being.
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Determination of heart rate variability with an electronic stethoscope.
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.
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Towards 24/7 continuous heart rate monitoring.
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.
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Cnota, James F; Gupta, Resmi; Michelfelder, Erik C; Ittenbach, Richard F
2011-11-01
To describe congenital heart disease death rates in infants born between 34 and 40 weeks, estimate the relationship between gestational age and congenital heart disease infant death rates, and compare congenital heart disease death rates across 1- and 2-week intervals in gestational age. The 2000 to 2003 national linked birth/infant death cohort datasets were obtained. Congenital heart disease deaths were identified by using International Statistical Classification of Diseases, 10th Revision codes. Proportional death rates were calculated by using congenital heart disease deaths and all live births. The relationship between congenital heart disease death rates and gestational age was determined. Death rates were compared across intervals. A total of 14.9 million records were analyzed. Congenital heart disease deaths occurred in 4736 infants (0.04%) born between 34 and 40 weeks. There was a significant, negative linear relationship between congenital heart disease death rate and gestational age (R(2) = 0.97). Comparisons across 1-week intervals varied (P = .02-.23). All 2-week intervals were statistically significant (P < .01). Congenital heart disease death rates decrease as gestational age approaches 40 weeks. These results should be considered before elective delivery for the sole indication of prenatally diagnosed congenital heart disease. Copyright © 2011 Mosby, Inc. All rights reserved.
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Desai, Nihar R.; Ross, Joseph S.; Kwon, Ji Young; Herrin, Jeph; Dharmarajan, Kumar; Bernheim, Susannah M.; Krumholz, Harlan M.; Horwitz, Leora I.
2017-01-01
Importance Readmission rates declined after announcement of the Hospital Readmission Reduction Program (HRRP), which penalizes hospitals for excess readmissions for acute myocardial infarction (AMI), heart failure (HF), and pneumonia. Objective To compare trends in readmission rates for target and non-target conditions, stratified by hospital penalty status. Design, Setting, Participants Retrospective cohort study of 48,137,102 hospitalizations of 20,351,161 Medicare fee-for-service beneficiaries over 64 years discharged between January 1, 2008 and June 30, 2015 from 3,497 hospitals. Difference interrupted time series models were used to compare trends in readmission rates by condition and penalty status. Exposure Hospital penalty status or target condition under the HRRP. Outcome 30-day risk adjusted, all-cause unplanned readmission rates for target and non-target conditions. Results In January 2008, the mean readmission rates for AMI, HF, pneumonia and non-target conditions were 21.9%, 27.5%, 20.1%, and 18.4% respectively at hospitals later subject to financial penalties (n=2,189) and 18.7%, 24.2%, 17.4%, and 15.7% at hospitals not subject to penalties (n=1,283). Between January 2008 and March 2010, prior to HRRP announcement, readmission rates were stable across hospitals (except AMI at non-penalty hospitals). Following announcement of HRRP (March 2010), readmission rates for both target and non-target conditions declined significantly faster for patients at hospitals later subject to financial penalties compared with those at non-penalized hospitals (AMI, additional decrease of −1.24 (95% CI, −1.84, −0.65) percentage points per year relative to non-penalty discharges; HF, −1.25 (−1.64, −0.65); pneumonia, −1.37 (−0.95, −1.80); non-target, −0.27 (−0.38, −0.17); p<0.001 for all). For penalty hospitals, readmission rates for target conditions declined significantly faster compared with non-target conditions (AMI: additional decline of −0
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Gorny, Alexander Wilhelm; Liew, Seaw Jia; Tan, Chuen Seng; Müller-Riemenschneider, Falk
2017-10-20
Many modern smart watches and activity trackers feature an optical sensor that estimates the wearer's heart rate. Recent studies have evaluated the performance of these consumer devices in the laboratory. The objective of our study was to examine the accuracy and sensitivity of a common wrist-worn tracker device in measuring heart rates and detecting 1-min bouts of moderate to vigorous physical activity (MVPA) under free-living conditions. Ten healthy volunteers were recruited from a large university in Singapore to participate in a limited field test, followed by a month of continuous data collection. During the field test, each participant would wear one Fitbit Charge HR activity tracker and one Polar H6 heart rate monitor. Fitbit measures were accessed at 1-min intervals, while Polar readings were available for 10-s intervals. We derived intraclass correlation coefficients (ICCs) for individual participants comparing heart rate estimates. We applied Centers for Disease Control and Prevention heart rate zone cut-offs to ascertain the sensitivity and specificity of Fitbit in identifying 1-min epochs falling into MVPA heart rate zone. We collected paired heart rate data for 2509 1-min epochs in 10 individuals under free-living conditions of 3 to 6 hours. The overall ICC comparing 1-min Fitbit measures with average 10-s Polar H6 measures for the same epoch was .83 (95% CI .63-.91). On average, the Fitbit tracker underestimated heart rate measures by -5.96 bpm (standard error, SE=0.18). At the low intensity heart rate zone, the underestimate was smaller at -4.22 bpm (SE=0.15). This underestimate grew to -16.2 bpm (SE=0.74) in the MVPA heart rate zone. Fitbit devices detected 52.9% (192/363) of MVPA heart rate zone epochs correctly. Positive and negative predictive values were 86.1% (192/223) and 92.52% (2115/2286), respectively. During subsequent 1 month of continuous data collection (270 person-days), only 3.9% of 1-min epochs could be categorized as MVPA according
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Analysis of long term heart rate variability: methods, 1/f scaling and implications
NASA Technical Reports Server (NTRS)
Saul, J. P.; Albrecht, P.; Berger, R. D.; Cohen, R. J.
1988-01-01
The use of spectral techniques to quantify short term heart rate fluctuations on the order of seconds to minutes has helped define the autonomic contributions to beat-to-beat control of heart rate. We used similar techniques to quantify the entire spectrum (0.00003-1.0 Hz) of heart rate variability during 24 hour ambulatory ECG monitoring. The ECG from standard Holter monitor recordings from normal subjects was sampled with the use of a phase locked loop, and a heart rate time series was constructed at 3 Hz. Frequency analysis of the heart rate signal was performed after a nonlinear filtering algorithm was used to eliminate artifacts. A power spectrum of the entire 24 hour record revealed power that was inversely proportional to frequency, 1/f, over 4 decades from 0.00003 to 0.1 Hz (period approximately 10 hours to 10 seconds). Displaying consecutive spectra calculated at 5 minute intervals revealed marked variability in the peaks at all frequencies throughout the 24 hours, probably accounting for the lack of distinct peaks in the spectra of the entire records.
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Heart rate profiles and energy cost of locomotion during cross-country skiing races.
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.
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Vagal Nerve Stimulation Evoked Heart Rate Changes and Protection from Cardiac Remodeling.
Agarwal, Rahul; Mokelke, Eric; Ruble, Stephen B; Stolen, Craig M
2016-02-01
This study investigated whether vagal nerve stimulation (VNS) leads to improvements in ischemic heart failure via heart rate modulation. At 7 ± 1 days post left anterior descending artery (LAD) ligation, 63 rats with myocardial infarctions (MI) were implanted with ECG transmitters and VNS devices (MI + VNS, N = 44) or just ECG transmitters (MI, N = 17). VNS stimulation was active from 14 ± 1 days to 8 ± 1 weeks post MI. The average left ventricular (LV) end diastolic volumes at 8 ± 1 weeks were MI = 672.40 μl and MI + VNS = 519.35 μl, p = 0.03. The average heart weights, normalized to body weight (± std) at 14 ± 1 weeks were MI = 3.2 ± 0.6 g*kg(-1) and MI + VNS = 2.9 ± 0.3 g*kg(-1), p = 0.03. The degree of cardiac remodeling was correlated with the magnitude of acute VNS-evoked heart rate (HR) changes. Further research is required to determine if the acute heart rate response to VNS activation is useful as a heart failure biomarker or as a tool for VNS therapy characterization.
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Assessing Metabolic Syndrome Through Increased Heart Rate During Exercise.
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.
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When an Increase in Central Systolic Pressure Overrides the Benefits of Heart Rate Lowering.
Messerli, Franz H; Rimoldi, Stefano F; Bangalore, Sripal; Bavishi, Chirag; Laurent, Stephane
2016-08-16
An elevated resting heart rate has been unequivocally linked to adverse cardiovascular events. Conversely, a physiologically low heart rate may confer longevity benefits. Moreover, pharmacological heart rate lowering reduces cardiovascular outcomes in patients with heart failure, with the magnitude of the reduction associated with survival benefit. In contrast, pharmacological heart rate lowering paradoxically increases cardiovascular events in hypertension, possibly because it elicits a ventricular-vascular mismatch, leading to increased central systolic blood pressure (BP). By the same hemodynamic mechanism, pharmacological heart rate lowering also engenders an increase in central (aortic) BP in coronary heart disease and, as a consequence, fails to decrease myocardial oxygen consumption. Whether in heart failure, hypertension, or coronary heart disease, or even athletes, heart rate lowering consistently increases central systolic pressure. The increase in central systolic BP is prone to abolish the potential benefits of heart rate lowering interventions, possibly accounting for failure to reduce outcomes in patients with hypertension and coronary artery disease. Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.
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[Design of hand-held heart rate variability acquisition and analysis system].
Li, Kaiyuan; Wang, Buqing; Wang, Weidong
2012-07-01
A design of handheld heart rate variability acquisition and analysis system is proposed. The system collects and stores the patient's ECG every five minutes through both hands touching on the electrodes, and then -uploads data to a PC through USB port. The system uses software written in LabVIEW to analyze heart rate variability parameters, The parameters calculated function is programmed and generated to components in Matlab.
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The effect of orthostatic stress on multiscale entropy of heart rate and blood pressure.
Turianikova, Zuzana; Javorka, Kamil; Baumert, Mathias; Calkovska, Andrea; Javorka, Michal
2011-09-01
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.
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Monitoring the fetal heart rate variability during labor.
Moslem, B; Mohydeen, A; Bazzi, O
2015-08-01
In respect to the main goal of our ongoing work for estimating the heart rate variability (HRV) from fetal electrocardiogram (FECG) signals for monitoring the health of the fetus, we investigate in this paper the possibility of extracting the fetal heart rate variability (HRV) directly from the abdominal composite recordings. Our proposed approach is based on a combination of two techniques: Periodic Component Analysis (PiCA) and recursive least square (RLS) adaptive filtering. The Fetal HRV of the estimated FECG signal is compared to a reference value extracted from an FECG signal recorded by using a spiral electrode attached directly to the fetal scalp. The results obtained show that the fetal HRV can be directly evaluated from the abdominal composite recordings without the need of recording an external reference signal.
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Methner, Carmen; Chouchani, Edward T; Buonincontri, Guido; Pell, Victoria R; Sawiak, Stephen J; Murphy, Michael P; Krieg, Thomas
2014-07-01
Recently it has been shown that the mitochondria-targeted S-nitrosothiol MitoSNO protects against acute ischaemia/reperfusion (IR) injury by inhibiting the reactivation of mitochondrial complex I in the first minutes of reperfusion of ischaemic tissue, thereby preventing free radical formation that underlies IR injury. However, it remains unclear how this transient inhibition of mitochondrial complex I-mediated free radicals at reperfusion affects the long-term recovery of the heart following IR injury. Here we determined whether the acute protection by MitoSNO at reperfusion prevented the subsequent development of post-myocardial infarction heart failure. Mice were subjected to 30 min left coronary artery occlusion followed by reperfusion and recovery over 28 days. MitoSNO (100 ng/kg) was applied 5 min before the onset of reperfusion followed by 20 min infusion (1 ng/kg/min). Infarct size and cardiac function were measured by magnetic resonance imaging (MRI) 24 h after infarction. MitoSNO-treated mice exhibited reduced infarct size and preserved function. In addition, MitoSNO at reperfusion improved outcome measures 28 days post-IR, including preserved systolic function (63.7 ±1.8% LVEF vs. 53.7 ± 2.1% in controls, P = 0.01) and tissue fibrosis. MitoSNO action acutely at reperfusion reduces infarct size and protects from post-myocardial infarction heart failure. Therefore, targeted inhibition of mitochondrial complex I in the first minutes of reperfusion by MitoSNO is a rational therapeutic strategy for preventing subsequent heart failure in patients undergoing IR injury. © 2014 The Authors. European Journal of Heart Failure published by John Wiley & Sons Ltd on behalf of European Society of Cardiology.
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Robust efficient estimation of heart rate pulse from video.
Xu, Shuchang; Sun, Lingyun; Rohde, Gustavo Kunde
2014-04-01
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.
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Robust efficient estimation of heart rate pulse from video
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
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Modeling of Diffusion Based Correlations Between Heart Rate Modulations and Respiration Pattern
2001-10-25
1 of 4 MODELING OF DIFFUSION BASED CORRELATIONS BETWEEN HEART RATE MODULATIONS AND RESPIRATION PATTERN R.Langer,(1) Y.Smorzik,(2) S.Akselrod,(1...generations of the bronchial tree. The second stage describes the oxygen diffusion process from the pulmonary gas in the alveoli into the pulmonary...patterns (FRC, TV, rate). Keywords – Modeling, Diffusion , Heart Rate fluctuations I. INTRODUCTION Under a whole-body management perception, the
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Pulse transducer with artifact signal attenuator. [heart rate sensors
NASA Technical Reports Server (NTRS)
Cash, W. H., Jr.; Polhemus, J. T. (Inventor)
1980-01-01
An artifact signal attenuator for a pulse rate sensor is described. The circuit for attenuating background noise signals is connected with a pulse rate transducer which has a light source and a detector for light reflected from blood vessels of a living body. The heart signal provided consists of a modulated dc signal voltage indicative of pulse rate. The artifact signal resulting from light reflected from the skin of the body comprises both a constant dc signal voltage and a modulated dc signal voltage. The amplitude of the artifact signal is greater and the frequency less than that of the heart signal. The signal attenuator circuit includes an operational amplifier for canceling the artifact signal from the output signal of the transducer and has the capability of meeting packaging requirements for wrist-watch-size packages.
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Tang, Yi-Da; Dewland, Thomas A; Wencker, Detlef; Katz, Stuart D
2009-12-01
Post-exercise heart rate recovery (HRR) is an index of parasympathetic function associated with clinical outcomes in populations with and without documented coronary heart disease. Decreased parasympathetic activity is thought to be associated with disease progression in chronic heart failure (HF), but an independent association between post-exercise HRR and clinical outcomes among such patients has not been established. We measured HRR (calculated as the difference between heart rate at peak exercise and after 1 minute of recovery) in 202 HF subjects and recorded 17 mortality and 15 urgent transplantation outcome events over 624 days of follow-up. Reduced post-exercise HRR was independently associated with increased event risk after adjusting for other exercise-derived variables (peak oxygen uptake and change in minute ventilation per change in carbon dioxide production slope), for the Heart Failure Survival Score (adjusted HR 1.09 for 1 beat/min reduction, 95% CI 1.05-1.13, P < .0001), and the Seattle Heart Failure Model score (adjusted HR 1.08 for one beat/min reduction, 95% CI 1.05-1.12, P < .0001). Subjects in the lowest risk tertile based on post-exercise HRR (>or=30 beats/min) had low risk of events irrespective of the risk predicted by the survival scores. In a subgroup of 15 subjects, reduced post-exercise HRR was associated with increased serum markers of inflammation (interleukin-6, r = 0.58, P = .024; high-sensitivity C-reactive protein, r = 0.66, P = .007). Post-exercise HRR predicts mortality risk in patients with HF and provides prognostic information independent of previously described survival models. Pathophysiologic links between autonomic function and inflammation may be mediators of this association.
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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.
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Heart Rates of Elementary Physical Education Students during the Dancing Classrooms Program
ERIC Educational Resources Information Center
Nelson, Larry; Evans, Melissa; Guess, Wendy; Morris, Mary; Olson, Terry; Buckwalter, John
2011-01-01
We examined how different types of dance activities, along with their duration, influenced heart rate responses among fifth-grade physical education students (N = 96) who participated in the Dancing Classrooms program. Results indicated that the overall Dancing Classrooms program elicits a moderate cardiovascular heart rate response (M = 124.4…
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Heart rate variability and heart rate turbulence in patients with polycystic ovary syndrome.
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.
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Kokki, Tommi; Sipilä, Hannu T; Teräs, Mika; Noponen, Tommi; Durand-Schaefer, Nicolas; Klén, Riku; Knuuti, Juhani
2010-01-01
In PET imaging respiratory and cardiac contraction motions interfere the imaging of heart. The aim was to develop and evaluate dual gating method for improving the detection of small targets of the heart. The method utilizes two independent triggers which are sent periodically into list mode data based on respiratory and ECG cycles. An algorithm for generating dual gated segments from list mode data was developed. The test measurements showed that rotational and axial movements of point source can be separated spatially to different segments with well-defined borders. The effect of dual gating on detection of small moving targets was tested with a moving heart phantom. Dual gated images showed 51% elimination (3.6 mm out of 7.0 mm) of contraction motion of hot spot (diameter 3 mm) and 70% elimination (14 mm out of 20 mm) of respiratory motion. Averaged activity value of hot spot increases by 89% when comparing to non-gated images. Patient study of suspected cardiac sarcoidosis shows sharper spatial myocardial uptake profile and improved detection of small myocardial structures such as papillary muscles. The dual gating method improves detection of small moving targets in a phantom and it is feasible in clinical situations.
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Effect of Heart rate on Basketball Three-Point Shot Accuracy
Ardigò, Luca P.; Kuvacic, Goran; Iacono, Antonio D.; Dascanio, Giacomo; Padulo, Johnny
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 spots just beyond the FIBA three-point line, i.e., about 7 m from the basket (two counter-clockwise “laps”) at different heart rates: rest (0HR), after warm-up (50%HRMAX [50HR]), and heart rate corresponding to 80% of its maximum value (80%HRMAX [80HR]). We found that 50HR does not significantly decrease 3S% (−15%, P = 0.255), while 80HR significantly does when compared to 0HR (−28%, P = 0.007). Given that 50HR does not decrease 3S% compared to 0HR, we believe that no preliminary warm-up is needed before entering a game in order to specifically achieve a high 3S%. Furthermore, 3S training should be performed in conditions of moderate-to-high fatigued state so that a high 3S% can be maintained during game-play. PMID:29467676
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Sacre, J W; Jellis, C L; Coombes, J S; Marwick, T H
2012-09-01
Poor prognosis associated with blunted post-exercise heart-rate recovery may reflect autonomic dysfunction. This study sought the accuracy of post-exercise heart-rate recovery in the diagnosis of cardiac autonomic neuropathy, which represents a serious, but often unrecognized complication of Type 2 diabetes. Clinical assessment of cardiac autonomic neuropathy and maximal treadmill exercise testing for heart-rate recovery were performed in 135 patients with Type 2 diabetes and negative exercise echocardiograms. Cardiac autonomic neuropathy was defined by abnormalities in ≥ 2 of 7 autonomic function markers, including four cardiac reflex tests and three indices of short-term (5-min) heart-rate variability. Heart-rate recovery was defined at 1-, 2- and 3-min post-exercise. Patients with cardiac autonomic neuropathy (n = 27; 20%) had lower heart-rate recovery at 1-, 2- and 3-min post-exercise (P < 0.01). Heart-rate recovery demonstrated univariate associations with autonomic function markers (r-values 0.20-0.46, P < 0.05). Area under the receiver-operating characteristic curve revealed good diagnostic performance of all heart-rate recovery parameters (range 0.80-0.83, P < 0.001). Optimal cut-offs for heart-rate recovery at 1-, 2- and 3-min post-exercise were ≤ 28 beats/min (sensitivity 93%, specificity 69%), ≤ 50 beats/min (sensitivity 96%, specificity 63%) and ≤ 52 beats/min (sensitivity 70%, specificity 84%), respectively. These criteria predicted cardiac autonomic neuropathy independently of relevant clinical and exercise test information (adjusted odds ratios 7-28, P < 0.05). Post-exercise heart-rate recovery provides an accurate diagnostic test for cardiac autonomic neuropathy in Type 2 diabetes. The high sensitivity and modest specificity suggests heart-rate recovery may be useful to screen for patients requiring clinical autonomic evaluation. © 2012 The Authors. Diabetic Medicine © 2012 Diabetes UK.
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Duley, Aaron R; Janelle, Christopher M; Coombes, Stephen A
2004-11-01
The cardiovascular system has been extensively measured in a variety of research and clinical domains. Despite technological and methodological advances in cardiovascular science, the analysis and evaluation of phasic changes in heart rate persists as a way to assess numerous psychological concomitants. Some researchers, however, have pointed to constraints on data analysis when evaluating cardiac activity indexed by heart rate or heart period. Thus, an off-line application toolkit for heart rate analysis is presented. The program, written with National Instruments' LabVIEW, incorporates a variety of tools for off-line extraction and analysis of heart rate data. Current methods and issues concerning heart rate analysis are highlighted, and how the toolkit provides a flexible environment to ameliorate common problems that typically lead to trial rejection is discussed. Source code for this program may be downloaded from the Psychonomic Society Web archive at www.psychonomic.org/archive/.
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Metoprolol improves survival in severe traumatic brain injury independent of heart rate control.
Zangbar, Bardiya; Khalil, Mazhar; Rhee, Peter; Joseph, Bellal; Kulvatunyou, Narong; Tang, Andrew; Friese, Randall S; O'Keeffe, Terence
2016-02-01
Multiple prior studies have suggested an association between survival and beta-blocker administration in patients with severe traumatic brain injury (TBI). However, it is unknown whether this benefit of beta-blockers is dependent on heart rate control. The aim of this study was to assess whether rate control affects survival in patients receiving metoprolol with severe TBI. Our hypothesis was that improved survival from beta-blockade would be associated with a reduction in heart rate. We performed a 7-y retrospective analysis of all blunt TBI patients at a level-1 trauma center. Patients aged >16 y with head abbreviated injury scale 4 or 5, admitted to the intensive care unit (ICU) from the operating room or emergency room (ER), were included. Patients were stratified into two groups: metoprolol and no beta-blockers. Using propensity score matching, we matched the patients in two groups in a 1:1 ratio controlling for age, gender, race, admission vital signs, Glasgow coma scale, injury severity score, mean heart rate monitored during ICU admission, and standard deviation of heart rate during the ICU admission. Our primary outcome measure was mortality. A total of 914 patients met our inclusion criteria, of whom 189 received beta-blockers. A propensity-matched cohort of 356 patients (178: metoprolol and 178: no beta-blockers) was created. Patients receiving metoprolol had higher survival than those patients who did not receive beta-blockers (78% versus 68%; P = 0.04); however, there was no difference in the mean heart rate (89.9 ± 13.9 versus 89.9 ± 15; P = 0.99). Nor was there a difference in the mean of standard deviation of the heart rates (14.7 ± 6.3 versus 14.4 ± 6.5; P = 0.65) between the two groups. In Kaplan-Meier survival analysis, patients who received metoprolol had a survival advantage (P = 0.011) compared with patients who did not receive any beta-blockers. Our study shows an association with improved survival in patients with severe TBI receiving
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Heart rate responses and fluid balance of competitive cross-country hang gliding pilots.
Morton, Darren P
2010-03-01
To evaluate the physiological challenges of competitive cross-country hang gliding. Seventeen experienced male pilots (age=41+/-9 y; mean+/-SD) were fitted with a monitor that recorded heart rate and altitude at 0.5 Hz throughout a competitive flight. Fluid losses were evaluated by comparing pilot pre- and postflight mass. The pilots' displacement was 88.4+/-43.7 km in 145.5+/-49.4 min. Mean flight altitude was 1902+/-427 m (range=1363-2601 m) with a maximum altitude of 2925+/-682 m (1870-3831 m). The mean in-flight heart rate of the pilots was 112+/-11 bpm (64+/-6% predicted HRmax). For all except one subject, heart rate was highest while launching (165+/-12 bpm, 93+/-7% predicted HRmax), followed by landing (154+/-13 bpm, 87+/-7% predicted HRmax). No statistically significant relationship was observed between heart rate during the launch and reported measures of state anxiety. Heart rate was inversely related (P<.01) to altitude for all pilots except one. Fluid loss during the flight was 1.32+/-0.70 L, which approximated 0.55 L/h, while mean in-flight fluid consumption was 0.39+/-0.44 L. Six pilots consumed no fluid during the flight. Even among experienced pilots, high heart rates are more a function of state anxiety than physical work demand. Fluid losses during flight are surprisingly moderate but pilots may still benefit from attending to fluid balance.
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Effects of head-down bed rest on complex heart rate variability: Response to LBNP testing
NASA Technical Reports Server (NTRS)
Goldberger, Ary L.; Mietus, Joseph E.; Rigney, David R.; Wood, Margie L.; Fortney, Suzanne M.
1994-01-01
Head-down bed rest is used to model physiological changes during spaceflight. We postulated that bed rest would decrease the degree of complex physiological heart rate variability. We analyzed continuous heart rate data from digitized Holter recordings in eight healthy female volunteers (age 28-34 yr) who underwent a 13-day 6 deg head-down bed rest study with serial lower body negative pressure (LBNP) trials. Heart rate variability was measured on a 4-min data sets using conventional time and frequency domain measures as well as with a new measure of signal 'complexity' (approximate entropy). Data were obtained pre-bed rest (control), during bed rest (day 4 and day 9 or 11), and 2 days post-bed rest (recovery). Tolerance to LBNP was significantly reduced on both bed rest days vs. pre-bed rest. Heart rate variability was assessed at peak LBNP. Heart rate approximate entropy was significantly decreased at day 4 and day 9 or 11, returning toward normal during recovery. Heart rate standard deviation and the ratio of high- to low-power frequency did not change significantly. We conclude that short-term bed rest is associated with a decrease in the complex variability of heart rate during LBNP testing in healthy young adult women. Measurement of heart rate complexity, using a method derived from nonlinear dynamics ('chaos theory'), may provide a sensitive marker of this loss of physiological variability, complementing conventional time and frequency domain statistical measures.
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Drewery, Merritt L; Spedale, Steven B; Lammi-Keefe, Carol J
2017-09-01
Heart rate (HR) and heart rate variability (HRV) are valuable markers of health. Although the underlying mechanism(s) are controversial, it is well documented that n-3 long chain polyunsaturated fatty acid (LCPUFA) intake improves HR and HRV in various populations. Autonomic modulation and/or alterations in cardiac electrophysiology are commonly cited as potential mechanisms responsible for these effects. This article reviews existing evidence for each and explores a separate mechanism which has not received much attention but has scientific merit. Based on presented evidence, it is proposed that n-3 LCPUFAs affect HR and HRV directly by autonomic modulation and indirectly by altering circulating factors, both dependently and independently of the autonomic nervous system. The evidence for changes in cardiac electrophysiology as the mechanism by which n-3 LCPUFAs affect HR and HRV needs strengthening. Copyright © 2017 Elsevier Ltd. All rights reserved.
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Heart Disease Death Rates Among Blacks and Whites Aged ≥35 Years - United States, 1968-2015.
Van Dyke, Miriam; Greer, Sophia; Odom, Erika; Schieb, Linda; Vaughan, Adam; Kramer, Michael; Casper, Michele
2018-03-30
Heart disease is the leading cause of death in the United States. In 2015, heart disease accounted for approximately 630,000 deaths, representing one in four deaths in the United States. Although heart disease death rates decreased 68% for the total population from 1968 to 2015, marked disparities in decreases exist by race and state. 1968-2015. The National Vital Statistics System (NVSS) data on deaths in the United States were abstracted for heart disease using diagnosis codes from the eighth, ninth, and tenth revisions of the International Classification of Diseases (ICD-8, ICD-9, and ICD-10) for 1968-2015. Population estimates were obtained from NVSS files. National and state-specific heart disease death rates for the total population and by race for adults aged ≥35 years were calculated for 1968-2015. National and state-specific black-white heart disease mortality ratios also were calculated. Death rates were age standardized to the 2000 U.S. standard population. Joinpoint regression was used to perform time trend analyses. From 1968 to 2015, heart disease death rates decreased for the total U.S. population among adults aged ≥35 years, from 1,034.5 to 327.2 per 100,000 population, respectively, with variations in the magnitude of decreases by race and state. Rates decreased for the total population an average of 2.4% per year, with greater average decreases among whites (2.4% per year) than blacks (2.2% per year). At the national level, heart disease death rates for blacks and whites were similar at the start of the study period (1968) but began to diverge in the late 1970s, when rates for blacks plateaued while rates for whites continued to decrease. Heart disease death rates among blacks remained higher than among whites for the remainder of the study period. Nationwide, the black-white ratio of heart disease death rates increased from 1.04 in 1968 to 1.21 in 2015, with large increases occurring during the 1970s and 1980s followed by small but steady
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Kroczek, A M; Häußinger, F B; Rohe, T; Schneider, S; Plewnia, C; Batra, A; Fallgatter, A J; Ehlis, A-C
2016-11-01
Drug-related cue exposure elicits craving and risk for relapse during recovery. Transcranial direct current stimulation is a promising research tool and possible treatment for relapse prevention. Enhanced functional neuroconnectivity is discussed as a treatment target. The goal of this research was to examine whether transcranial direct current stimulation affected cortical hemodynamic indicators of functional connectivity, craving, and heart rate variability during smoking-related cue exposure in non-treatment-seeking smokers. In vivo smoking cue exposure supported by a 2mA transcranial direct current stimulation (anode: dorsolateral prefrontal cortex, cathode: orbitofrontal cortex; placebo-controlled, randomized, double-blind) in 29 (age: M=25, SD=5) German university students (smoking at least once a week). Cue reactivity was assessed on an autonomous (heart rate variability) and a subjective level (craving ratings). Functional near-infrared spectroscopy measured changes in the concentration of deoxygenated hemoglobin, and seed-based correlation analysis was used to quantify prefrontal connectivity of brain regions involved in cue reactivity. Cue exposure elicited increased subjective craving and heart rate variability changes in smokers. Connectivity between the orbitofrontal and dorsolateral prefrontal cortex was increased in subjects receiving verum compared to placebo stimulation (d=0.66). Hemodynamics in the left dorsolateral prefrontal cortex, however, increased in the group receiving sham stimulation (η 2 =0.140). Transcranial direct current stimulation did not significantly alter craving or heart rate variability during cue exposure. Prefrontal connectivity - between regions involved in the processing of reinforcement value and cognitive control - was increased by anodal transcranial direct current stimulation during smoking cue exposure. Possible clinical implications should be considered in future studies. Copyright © 2016 Elsevier Ireland Ltd. All
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Bradycardia in perspective-not all reductions in heart rate need immediate intervention.
Mason, Keira P; Lönnqvist, Per-Arne
2015-01-01
According to Wikipedia, the word 'bradycardia' stems from the Greek βραδύς, bradys, 'slow', and καρδία, kardia, 'heart'. Thus, the meaning of bradycardia is slow heart rate but not necessarily too slow heart rate. If looking at top endurance athletes they may have a resting heart rate in the very low thirties without needing emergent intervention with anticholinergics, isoprenaline, epinephrine, chest compressions or the insertion of an emergency pacemaker (Figure 1). In fact, they withstand these episodes without incident, accommodating with a compensatory increase in stroke volume to preserve and maintain cardiac output. With this in mind, it is difficult for the authors to fully understand and agree with the general sentiment amongst many pediatric anesthesiologists that all isolated bradycardia portends impending doom and must be immediately treated with resuscitative measures. © 2014 John Wiley & Sons Ltd.
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Evaluation of a strapless heart rate monitor during simulated flight tasks.
Wang, Zhen; Fu, Shan
2016-01-01
Pilots are under high task demands during flight. Monitoring pilot's physiological status is very important in the evaluation of pilot's workload and flight safety. Recently, physiological status monitor (PSM) has been embedded into a watch that can be used without a conventional chest strap. This makes it possible to unobtrusively monitor, log and transmit pilot's physiological measurements such as heart rate (HR) during flight tasks. The purpose of this study is to validate HR recorded by a strapless heart rate watch against criterion ECG-derived HR. Ten commercial pilots (mean ± SD : age: 39.1 ± 7.8 years; total flight hours 7173.2 ± 5270.9 hr) performed three routinely trained flight tasks in a full flight simulator: wind shear go-around (WG), takeoff and climb (TC), and hydraulic failure (HF). For all tasks combined (overall) and for each task, differences between the heart rate watch measurements and the criterion data were small (mean difference [95% CI]: overall: -0.71 beats/min [-0.85, -0.57]; WG: -0.90 beats/min [-1.15, -0.65]; TC: -0.69 beats/min [-0.98, -0.40]; HF: -0.61 beats/min [-0.80, -0.42]). There were high correlations between the heart rate watch measurements and the ECG-derived HR for all tasks (r ≥ 0.97, SEE < 3). Bland-Altman plots also show high agreements between the watch measurements and the criterion HR. These results suggest that the strapless heart rate watch provides valid measurements of HR during simulated flight tasks and could be a useful tool for pilot workload evaluation.
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Hopfield neural network and optical fiber sensor as intelligent heart rate monitor
NASA Astrophysics Data System (ADS)
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.
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gHRV: Heart rate variability analysis made easy.
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.
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A comparison of two recorders for obtaining in-flight heart rate data.
Dahlstrom, Nicklas; Nahlinder, Staffan
2006-09-01
: Measurement of mental workload has been widely used for evaluation of aircraft design, mission analysis and assessment of pilot performance during flight operations. Heart rate is the psychophysiological measure that has been most frequently used for this purpose. The risk of interference with flight safety and pilot performance, as well as the generally constrained access to flights, make it difficult for researchers to collect in-flight heart rate data. Thus, this study was carried out to investigate whether small, non-intrusive sports recorders can be used for in-flight data collection for research purposes. Data was collected from real and simulated flights with student pilots using the Polar Team System sports recorder and the Vitaport II, a clinical and research recording device. Comparison of the data shows that in-flight heart rate data from the smaller and less intrusive sports recorder have a correlation of.981 with that from the clinical recorder, thus indicating that the sports recorder is reliable and cost-effective for obtaining heart rate data for many research situations.
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Clark, Steven L; Hamilton, Emily F; Garite, Thomas J; Timmins, Audra; Warrick, Philip A; Smith, Samuel
2017-02-01
Despite intensive efforts directed at initial training in fetal heart rate interpretation, continuing medical education, board certification/recertification, team training, and the development of specific protocols for the management of abnormal fetal heart rate patterns, the goals of consistently preventing hypoxia-induced fetal metabolic acidemia and neurologic injury remain elusive. The purpose of this study was to validate a recently published algorithm for the management of category II fetal heart rate tracings, to examine reasons for the birth of infants with significant metabolic acidemia despite the use of electronic fetal heart rate monitoring, and to examine critically the limits of electronic fetal heart rate monitoring in the prevention of neonatal metabolic acidemia. The potential performance of electronic fetal heart rate monitoring under ideal circumstances was evaluated in an outcomes-blinded examination fetal heart rate tracing of infants with metabolic acidemia at birth (base deficit, >12) and matched control infants (base deficit, <8) under the following conditions: (1) expert primary interpretation, (2) use of a published algorithm that was developed and endorsed by a large group of national experts, (3) assumption of a 30-minute period of evaluation for noncritical category II fetal heart rate tracings, followed by delivery within 30 minutes, (4) evaluation without the need to provide patient care simultaneously, and (5) comparison of results under these circumstances with those achieved in actual clinical practice. During the study period, 120 infants were identified with an arterial cord blood base deficit of >12 mM/L. Matched control infants were not demographically different from subjects. In actual practice, operative intervention on the basis of an abnormal fetal heart rate tracings occurred in 36 of 120 fetuses (30.0%) with metabolic acidemia. Based on expert, algorithm-assisted reviews, 55 of 120 patients with acidemia (45.8%) were
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Increase in hospital admission rates for heart failure in The Netherlands, 1980-1993.
Reitsma, J. B.; Mosterd, A.; de Craen, A. J.; Koster, R. W.; van Capelle, F. J.; Grobbee, D. E.; Tijssen, J. G.
1996-01-01
OBJECTIVE: To study the trend in hospital admission rates for heart failure in the Netherlands from 1980 to 1993. DESIGN: All hospital admissions in the Netherlands with a principal discharge diagnosis of heart failure were analysed. In addition, individual records of heart failure patients from a subset of 7 hospitals were analysed to estimate the frequency and timing of readmissions. RESULTS: The total number of discharges for men increased from 7377 in 1980 to 13 022 in 1993, and for women from 7064 to 12 944. From 1980 through 1993 age adjusted discharge rates rose 48% for men and 40% for women. Age adjusted in-hospital mortality for heart failure decreased from 19% in 1980 to 15% in 1993. For all age groups in-hospital mortality for men was higher than for women. The mean length of hospital admissions in 1993 was 14.0 days for men and 16.4 days for women. A review of individual patient records from a 6.3% sample of all hospital admissions in the Netherlands indicated that within a 2 year period 18% of the heart failure patients were admitted more than once and 5% more than twice. CONCLUSIONS: For both men and women a pronounced increase in age adjusted discharge rates for heart failure was observed in the Netherlands from 1980 to 1993. Readmissions were a prominent feature among heart failure patients. Higher survival rates after acute myocardial infarction and the longer survival of patients with heart disease, including heart failure may have contributed to the observed increase. The importance of advances in diagnostic tools and of possible changes in admission policy remain uncertain. PMID:8944582
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Wdowczyk, Joanna; Makowiec, Danuta; Dorniak, Karolina; Gruchała, Marcin
2016-01-01
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 non-conducted 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.
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Davidovic, Goran; Iric-Cupic, Violeta; Milanov, Srdjan
2013-01-01
Acute myocardial infarction as a form of coronary heart disease is characterized by permanent damage/loss of anatomical and functional cardiac tissue. Diagnosis of STEMI includes data on anginal pain and persistent ST-segment elavation. According to the numerous epidemiological studies, arterial blood pressure and heart rate are offten increased especially during the first hours of pain due to domination of sympathetic response. We wanted to investigate the associated influence of heart rate greater than 80 beats per minute and hypertension on the mortality in patients with anterior wall STEMI. Research included 140 patients treated in Coronary Unit, Clinical Center Kragujevac form January 2001 to June 2006. Heart rate was calculated as the mean value of baseline and heart rate in the first 30 minutes after admission, recorded on monitor and electrocardiogram. Data for history of hypertension were collected and blood pressure levels were measured in a lying position after 5 minutes of rest, and classified according to the VII JNC recommendations as confirmation of hypertension. Collected data were analyzed in SPSS 13.0 for Windows. Heart rate greater than 80 bpm influences the hospital mortality. Systolic blood pressure levels were higher in the survivors, while for the diastolic there was no difference. History of hypertension was singled out as a significant predictor of mortality without difference between the respondents with heart rate greater and lower than 80 bpm in the survivors and fatal. Increased heart rate and hypertension at admission are significant predictors of mortality in patients with anterior wall STEMI. PMID:23724155
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Heart Rate Detection During Sleep Using a Flexible RF Resonator and Injection-Locked PLL Sensor.
Kim, Sung Woo; Choi, Soo Beom; An, Yong-Jun; Kim, Byung-Hyun; Kim, Deok Won; Yook, Jong-Gwan
2015-11-01
Novel nonintrusive technologies for wrist pulse detection have been developed and proposed as systems for sleep monitoring using three types of radio frequency (RF) sensors. The three types of RF sensors for heart rate measurement on wrist are a flexible RF single resonator, array resonators, and an injection-locked PLL resonator sensor. To verify the performance of the new RF systems, we compared heart rates between presleep time and postsleep onset time. Heart rates of ten subjects were measured using the RF systems during sleep. All three RF devices detected heart rates at 0.2 to 1 mm distance from the skin of the wrist over clothes made of cotton fabric. The wrist pulse signals of a flexible RF single resonator were consistent with the signals obtained by a portable piezoelectric transducer as a reference. Then, we confirmed that the heart rate after sleep onset time significantly decreased compared to before sleep. In conclusion, the RF system can be utilized as a noncontact nonintrusive method for measuring heart rates during sleep.
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Developmental Change in Feedback Processing as Reflected by Phasic Heart Rate Changes
ERIC Educational Resources Information Center
Crone, Eveline A.; Jennings, J. Richard; Van der Molen, Maurits W.
2004-01-01
Heart rate was recorded from 3 age groups (8-10, 12, and 20-26 years) while they performed a probabilistic learning task. Stimuli had to be sorted by pressing a left versus right key, followed by positive or negative feedback. Adult heart rate slowed following negative feedback when stimuli were consistently mapped onto the left or right key…
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Middle School Student's Heart Rates during Different Curricular Activities in Physical Education
ERIC Educational Resources Information Center
Gao, Zan; Hannon, James C.; Carson, Russell L.
2009-01-01
The purpose of this study was to determine if students' heart rate outcomes in physical education varied as a function of activity and grade. A total of 146 sixth to eighth graders participated in different activities (i.e., walking/jogging, line dancing, soccer, and catch ball). Their average heart rate (AHR) and percentage of time in and above…
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Heart Rate and Treatment Effect in Children with Disruptive Behavior Disorders
ERIC Educational Resources Information Center
Stadler, Christina; Grasmann, Dorte; Fegert, Jorg M.; Holtmann, Martin; Poustka, Fritz; Schmeck, Klaus
2008-01-01
Objective: To examine whether children with disruptive behavior disorders (DBDs; hyperkinetic conduct disorder, conduct disorder, hyperkinetic disorder) characterized by low heart rate profit less from an intensive cognitive behavioral intervention aimed at reducing impulsive, oppositional and aggressive behavior problems. Method: Basal heart rate…
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Practical remarks on the heart rate and saturation measurement methodology
NASA Astrophysics Data System (ADS)
Kowal, M.; Kubal, S.; Piotrowski, P.; Staniec, K.
2017-05-01
A surface reflection-based method for measuring heart rate and saturation has been introduced as one having a significant advantage over legacy methods in that it lends itself for use in special applications such as those where a person’s mobility is of prime importance (e.g. during a miner’s work) and excluding the use of traditional clips. Then, a complete ATmega1281-based microcontroller platform has been described for performing computational tasks of signal processing and wireless transmission. In the next section remarks have been provided regarding the basic signal processing rules beginning with raw voltage samples of converted optical signals, their acquisition, storage and smoothing. This chapter ends with practical remarks demonstrating an exponential dependence between the minimum measurable heart rate and the readout resolution at different sampling frequencies for different cases of averaging depth (in bits). The following section is devoted strictly to the heart rate and hemoglobin oxygenation (saturation) measurement with the use of the presented platform, referenced to measurements obtained with a stationary certified pulsoxymeter.
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Dutra, Rosane Menezes Faria; Neves, Itamara Lucia Itagiba; Neves, Ricardo Simões; Atik, Edmar; de Paula Santos, Ubiratan
2014-01-01
OBJECTIVES: In this observational study, we evaluated the peripheral oxygen saturation (SpO2), heart rate, and blood pressure of children with cyanotic congenital heart disease who were undergoing dental extraction. METHODS: Forty-four patients between the ages of 6 and 12 years who underwent upper primary tooth extraction were included in the study. Of these, 20 patients were in the cyanotic congenital heart disease group and 24 were in the control group. RESULTS: Peripheral oxygen saturation, heart rate, and systolic blood pressure in the cyanotic congenital heart disease group varied quite significantly during the treatment protocol (p<0.05), with values of 80.5% (±7.6) to 82.8% (±7.8), 95.3 beats per minute (bpm) (±11.3) to 101.3 bpm (±9.8), and 93.6 mm Hg (±13,3) to 103.8 mm Hg (±12.7), respectively. The variations in the control group during the procedure were also significant. CONCLUSIONS: The changes observed during the study protocol, although statistically significant, were mild and lacked clinical relevance. The results indicate that dental treatment of children with cyanotic heart disease using a standardized protocol in decentralized offices without the support of a surgical center is safe. PMID:24838895
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Nearing, Bruce D; Libbus, Imad; Amurthur, Badri; Kenknight, Bruce H; Verrier, Richard L
2016-09-01
Chronic vagus nerve stimulation (VNS) applied to produce biomimetic levels of parasympathetic activation is feasible, well tolerated, safe, improves left ventricular ejection fraction, NYHA class, heart rate variability, and baroreflex function, and reduces T-wave alternans (TWA) in patients with chronic heart failure. However, the acute effects of VNS on beat-to-beat heart rate dynamics have not been systematically characterized in humans. We evaluated acute effects of VNS on R-R-interval dynamics during the VNS titration period in patients (n = 59) enrolled in ANTHEM-HF trial by quantifying effects during continuous cyclic VNS (14-seconds on-time, 66-seconds off-time) adjusted to the maximum tolerable dose without excessive (<4 bpm) bradycardia during the 10-week titration period. VNS elicited an immediate change in heart rate that was correlated to VNS current amplitude, pulse width, and frequency. Heart rate decreased more in the 28 patients with right-sided stimulation (-2.22 ± 0.13 bpm) than in the 31 patients with left-sided stimulation (-0.60 ± 0.08 bpm, P < 0.001). The linear correlation between stimulus intensity and lengthening of the R-R interval was stronger among the 28 patients with right-sided VNS implantation (r = 0.88, P < 0.0001) than among the 31 patients with left-sided VNS implantation (r = 0.49, P < 0.002). In all patients, the heart rate change elicited by VNS was significantly greater than the change during the same timing intervals in 10 randomly selected patients without stimulation (+0.08 ± 0.06 bpm, P < 0.001). Instantaneous heart rate change during therapeutic levels of VNS in patients with heart failure indicates consistent modulation of the autonomic nervous system for both left- and right-sided stimulation. © 2016 The Authors. Journal of Cardiovascular Electrophysiology published by Wiley Periodicals, Inc.
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Effect of training mode on post-exercise heart rate recovery of trained cyclists.
McDonald, Kelia G; Grote, Silvie; Shoepe, Todd C
2014-06-28
The sympathetic nervous system dominates the regulation of body functions during exercise. Therefore after exercise, the sympathetic nervous system withdraws and the parasympathetic nervous system helps the body return to a resting state. In the examination of this relationship, the purpose of this study was to compare recovery heart rates (HR) of anaerobically versus aerobically trained cyclists. With all values given as means ± SD, anaerobically trained track cyclists (n=10, age=25.9 ± 6.0 yrs, body mass=82.7 ± 7.1 kg, body fat=10.0 ± 6.3%) and aerobically trained road cyclists (n=15, age=39.9 ± 8.5 yrs, body mass=75.3 ± 9.9 kg, body fat=13.1 ± 4.5%) underwent a maximal oxygen uptake test. Heart rate recovery was examined on a relative basis using heart rate reserve as well as the absolute difference between maximum HR and each of two recovery HRs. The post-exercise change in HR at minute one for the track cyclists and road cyclists respectively were 22 ± 8 bpm and 25 ± 12 bpm. At minute two, the mean drop for track cyclists was significantly (p<0.05) greater than the road cyclists (52 ± 15 bpm and 64 ± 11 bpm). Training mode showed statistically significant effects on the speed of heart rate recovery in trained cyclists. Greater variability in recovery heart rate at minute two versus minute one suggests that the heart rate should be monitored longer than one minute of recovery for a better analysis of post-exercise autonomic shift.
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Comparative evaluation of heart rate-based monitors: Apple Watch vs Fitbit Charge HR.
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.
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Changes in heart rate associated with contest outcome in agonistic encounters in lobsters.
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.
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Massaro, An N; Campbell, Heather E; Metzler, Marina; Al-Shargabi, Tareq; Wang, Yunfei; du Plessis, Adre; Govindan, Rathinaswamy B
2017-04-01
To determine whether measures of heart rate variability are related to changes in temperature during rewarming after therapeutic hypothermia for hypoxic-ischemic encephalopathy. Prospective observational study. Level 4 neonatal ICU in a free-standing academic children's hospital. Forty-four infants with moderate to severe hypoxic-ischemic encephalopathy treated with therapeutic hypothermia. Continuous electrocardiogram data from 2 hours prior to rewarming through 2 hours after completion of rewarming (up to 10 hr) were analyzed. Median beat-to-beat interval and measures of heart rate variability were quantified including beat-to-beat interval SD, low and high frequency relative spectral power, detrended fluctuation analysis short and long α exponents (αS and αL), and root mean square short and long time scales. The relationships between heart rate variability measures and esophageal/axillary temperatures were evaluated. Heart rate variability measures low frequency, αS, and root mean square short and long time scales were negatively associated, whereas αL was positively associated, with temperature (p < 0.01). These findings signify an overall decrease in heart rate variability as temperature increased toward normothermia. Measures of heart rate variability are temperature dependent in the range of therapeutic hypothermia to normothermia. Core body temperature needs to be considered when evaluating heart rate variability metrics as potential physiologic biomarkers of illness severity in hypoxic-ischemic encephalopathy infants undergoing therapeutic hypothermia.
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Dose-dependent heart rate reducing effect of nizatidine, a histamine H2-receptor antagonist.
Hinrichsen, H; Halabi, A; Fuhrmann, G; Kirch, W
1993-01-01
1. Twelve healthy subjects were treated in a randomised placebo-controlled crossover study with placebo, 150 mg, 300 mg, and 600 mg nizatidine, 100 mg pirenzepine, and 300 mg nizatidine plus 100 mg pirenzepine for 1 week each. 2. On the seventh treatment day, heart rate, blood pressure, systolic time intervals, impedance cardiographic and Doppler ultrasound variables were measured. 3. Stroke volume and blood pressure were not altered by nizatidine and/or pirenzepine. By contrast, heart rate and cardiac output significantly (P < 0.05) decreased in a dose-dependent manner 1.5 and 3 h after administration of 300 and 600 mg nizatidine. Treatment with 150 mg nizatidine led to similar though non-significant trends. 4. While a slightly insignificant rise in heart rate was detected with pirenzepine alone, heart rate and cardiac output remained unchanged upon combined nizatidine and pirenzepine treatment as compared with placebo and baseline values. 5. In conclusion, nizatidine reduced heart rate and cardiac output in a dose-dependent manner, whereas this negative chronotropic effect was counteracted by concurrent administration of the anti-cholinergic drug pirenzepine. PMID:8099802
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Universal design of a microcontroller and IoT system to detect the heart rate
NASA Astrophysics Data System (ADS)
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).
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Aksentijević, Dunja; Lewis, Hannah R; Shattock, Michael J
2016-02-01
What is the central question of this study? Rate-pressure product (RPP) is commonly used as an index of cardiac 'effort'. In canine and human hearts (which have a positive force-frequency relationship), RPP is linearly correlated with oxygen consumption and has therefore been widely adopted as a species-independent index of cardiac work. However, given that isolated rodent hearts demonstrate a negative force-frequency relationship, its use in this model requires validation. What is the main finding and its importance? Despite its widespread use, RPP is not correlated with oxygen consumption (or cardiac 'effort') in the Langendorff-perfused isolated rat heart. This lack of correlation was also evident when perfusions included a range of metabolic substrates, insulin or β-adrenoceptor stimulation. Langendorff perfusion of hearts isolated from rats and mice has been used extensively for physiological, pharmacological and biochemical studies. The ability to phenotype these hearts reliably is, therefore, essential. One of the commonly used indices of function is rate-pressure product (RPP); a rather ill-defined index of 'work' or, more correctly, 'effort'. Rate-pressure product, as originally described in dog or human hearts, was shown to be correlated with myocardial oxygen consumption (MV̇O2). Despite its widespread use, the application of this index to rat or mouse hearts (which, unlike the dog or human, have a negative force-frequency relationship) has not been characterized. The aim of this study was to examine the relationship between RPP and MV̇O2 in Langendorff-perfused rat hearts. Paced hearts (300-750 beats min(-1)) were perfused either with Krebs-Henseleit (KH) buffer (11 mm glucose) or with buffer supplemented with metabolic substrates and insulin. The arteriovenous oxygen consumption (MV̇O2) was recorded. Metabolic status was assessed using (31) P magnetic resonance spectroscopy and lactate efflux. Experiments were repeated in the presence of
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Alterations in the heart rate and activity rhythms of three orbital astronauts on a space mission.
Liu, Zhizhen; Wan, Yufeng; Zhang, Lin; Tian, Yu; Lv, Ke; Li, Yinghui; Wang, Chunhui; Chen, Xiaoping; Chen, Shanguang; Guo, Jinhu
2015-01-01
Environmental factors in space are dramatically different from those on Earth. The spaceflight environment has been known to influence human physiology and behavior on orbital missions. In this study, we investigated alterations in the diurnal rhythms of activity and heart rate of three Chinese astronauts on a space mission. An analysis of the heart rate data showed a significant decrease in heart rate amplitudes during flight in all three subjects. The heart rate amplitudes of all the three astronauts were significantly dampened during flight, and the minimum as well as the maximum value of heart rate increased after flight. A phase shift in heart rate was observed in one of the three astronauts after flight. These results demonstrate the influence of spaceflight on heart physiology and function. In addition, a significant decrease in body trunk activity and rhythmicity occurred during flight, demonstrating that the spaceflight environment disturbs motion adaptation and diurnal activity rhythms. Copyright © 2015 The Committee on Space Research (COSPAR). Published by Elsevier Ltd. All rights reserved.
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Addison, Paul S; Foo, David M H; Jacquel, Dominique
2017-07-01
The extraction of heart rate from a video-based biosignal during motion using a novel wavelet-based ensemble averaging method is described. Running Wavelet Archetyping (RWA) allows for the enhanced extraction of pulse information from the time-frequency representation, from which a video-based heart rate (HRvid) can be derived. This compares favorably to a reference heart rate derived from a pulse oximeter.
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The effects of incubation temperature and experimental design on heart rates of lizard embryos.
Hulbert, Austin C; Mitchell, Timothy S; Hall, Joshua M; Guiffre, Cassia M; Douglas, Danielle C; Warner, Daniel A
2017-08-01
Many studies of phenotypic plasticity alter environmental conditions during embryonic development, yet only measure phenotypes at the neonatal stage (after embryonic development). However, measuring aspects of embryo physiology enhances our understanding of how environmental factors immediately affect embryos, which aids our understanding of developmental plasticity. While current research on reptile developmental plasticity has demonstrated that fluctuating incubation temperatures affect development differently than constant temperatures, most research on embryo physiology is still performed with constant temperature experiments. In this study, we noninvasively measured embryonic heart rates of the brown anole (Anolis sagrei), across ecologically relevant fluctuating temperatures. We incubated eggs under temperatures measured from potential nests in the field and examined how heart rates change through a diel cycle and throughout embryonic development. We also evaluated how experimental design (e.g., repeated vs. single measures designs, constant vs. fluctuating temperatures) and different protocols (e.g., removing eggs from incubators) might influence heart rate. We found that heart rates were correlated with daily temperature and increased through development. Our findings suggest that experimenters have reasonable flexibility in choosing an experimental design to address their questions; however, some aspects of design and protocol can potentially influence estimations of heart rates. Overall, we present the first ecologically relevant measures of anole embryonic heart rates and provide recommendations for experimental designs for future experiments. © 2017 Wiley Periodicals, Inc.
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[Changes in heart rate variability after myocardial infarction. Value of Poincareé's diagram].
Copie, X; Le Heuzey, J Y; Iliou, M C; Pousset, F; Lavergne, T; Guize, L
1995-11-01
The variability of the heart rate is reduced after myocardial infarction. It then progressively increases, to return to near normal values after several months. However, these changes in heart rate variability occur at the same time as slowing of the heart rate which makes interpretation difficult. Poincaré's diagram is constructed from a Holter recording plotting each RR interval against the preceding RR interval. The authors have developed a geometric approach to this diagram to evaluate parasympathetic tone for a given heart rate. By measuring the dispersion in height of the Poincaré's diagram, the authors evaluate the shor-term variability for a given RR interval. Two 24 hr Holter recordings were performed in 52 patients at one and two weeks after a myocardial infarction. The dispersion in the height of the Poincaré's diagrams was measured at the 10th, 25th, 50th, 75th and 90th percentiles of the total dispersion. The authors have shown an increase in the short-term variability of the shortest RR intervals (1th, 25th and 50th percentiles) which is not observed in the longer RR intervals (75th and 90th percentiles). In conclusion, theres is an increase in the heart rate variability at the shortest RR intervals. This suggests that the recovery of parasympathic tone after myocardial infarction occurs mainly at the fastest heart rates.
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General anesthesia suppresses normal heart rate variability in humans
NASA Astrophysics Data System (ADS)
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.
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Hamelmann, Paul; Vullings, Rik; Schmitt, Lars; Kolen, Alexander F; Mischi, Massimo; van Laar, Judith O E H; Bergmans, Jan W M
2017-09-21
Doppler ultrasound (US) is the most commonly applied method to measure the fetal heart rate (fHR). When the fetal heart is not properly located within the ultrasonic beam, fHR measurements often fail. As a consequence, clinical staff need to reposition the US transducer on the maternal abdomen, which can be a time consuming and tedious task. In this article, a method is presented to aid clinicians with the positioning of the US transducer to produce robust fHR measurements. A maximum likelihood estimation (MLE) algorithm is developed, which provides information on fetal heart location using the power of the Doppler signals received in the individual elements of a standard US transducer for fHR recordings. The performance of the algorithm is evaluated with simulations and in vitro experiments performed on a beating-heart setup. Both the experiments and the simulations show that the heart location can be accurately determined with an error of less than 7 mm within the measurement volume of the employed US transducer. The results show that the developed algorithm can be used to provide accurate feedback on fetal heart location for improved positioning of the US transducer, which may lead to improved measurements of the fHR.
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Borneman, Tracy E.; Rose, Eli T.; Simons, Theodore R.
2014-01-01
An organism's heart rate is commonly used as an indicator of physiological stress due to environmental stimuli. We used heart rate to monitor the physiological response of American Oystercatchers (Haematopus palliatus) to human activity in their nesting environment. We placed artificial eggs with embedded microphones in 42 oystercatcher nests to record the heart rate of incubating oystercatchers continuously for up to 27 days. We used continuous video and audio recordings collected simultaneously at the nests to relate physiological response of birds (heart rate) to various types of human activity. We observed military and civilian aircraft, off-road vehicles, and pedestrians around nests. With the exception of high-speed, low-altitude military overflights, we found little evidence that oystercatcher heart rates were influenced by most types of human activity. The low-altitude flights were the only human activity to significantly increase average heart rates of incubating oystercatchers (12% above baseline). Although statistically significant, we do not consider the increase in heart rate during high-speed, low-altitude military overflights to be of biological significance. This noninvasive technique may be appropriate for other studies of stress in nesting birds.
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The Accuracy and Validity of iOS-Based Heart Rate Apps During Moderate to High Intensity Exercise.
Bouts, Alexa M; Brackman, Lauren; Martin, Elizabeth; Subasic, Adam M; Potkanowicz, Edward S
2018-01-01
People use their smartphones for everything from web browsing to tracking fitness metrics. However, it is unclear whether smartphone-based apps that use photoplethysmography to measure heart rate are an accurate or valid measure of exercise intensity. Purpose was to determine the accuracy and validity of two iOS-based heart rate monitors, Runtastic Heart Rate Monitor and Pulse Tracker PRO by Runtastic (Runtastic) and Instant Heart Rate+: Heart Rate and Pulse Monitor by Azumio (Instant Heart Rate), when compared to the electrocardiogram (ECG) and Polar® T31 uncoded heart rate monitor from moderate to vigorous intensity exercise. Participants were 15 male and female regularly active college students. Pre-exercise heart rate and blood pressure were recorded and then participants exercised on a stationary bike at a pedal rate of between 50-60 rpms. After completing a warm-up stage at 40% of age estimated maximum heart rate (AEMHR), exercise intensity progressed from 50% of AEMHR through to 85% of AEMHR in eight, 5-minute stages. At the end of each stage, and having achieved steady-state, heart rates were recorded from each apparatus. After completing the final stage, participants completed a cooldown at 40% of their AEMHR. Post-exercise heart rate and blood pressure were also recorded to ensure full recovery to baseline. There was a strong positive correlation between the Polar® monitor and the ECG during all stages. However, there were not strong correlations for either of the smartphone-based apps at any time point. Although there were weak correlations between the smartphone-based apps and ECG and Polar®, further studies need to be conducted to determine if inaccuracy is due to user error (finger placement, finger temperature, etc.) or the technology behind the apps.
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The Accuracy and Validity of iOS-Based Heart Rate Apps During Moderate to High Intensity Exercise
BOUTS, ALEXA M.; BRACKMAN, LAUREN; MARTIN, ELIZABETH; SUBASIC, ADAM M.; POTKANOWICZ, EDWARD S.
2018-01-01
People use their smartphones for everything from web browsing to tracking fitness metrics. However, it is unclear whether smartphone-based apps that use photoplethysmography to measure heart rate are an accurate or valid measure of exercise intensity. Purpose was to determine the accuracy and validity of two iOS-based heart rate monitors, Runtastic Heart Rate Monitor and Pulse Tracker PRO by Runtastic (Runtastic) and Instant Heart Rate+: Heart Rate and Pulse Monitor by Azumio (Instant Heart Rate), when compared to the electrocardiogram (ECG) and Polar® T31 uncoded heart rate monitor from moderate to vigorous intensity exercise. Participants were 15 male and female regularly active college students. Pre-exercise heart rate and blood pressure were recorded and then participants exercised on a stationary bike at a pedal rate of between 50–60 rpms. After completing a warm-up stage at 40% of age estimated maximum heart rate (AEMHR), exercise intensity progressed from 50% of AEMHR through to 85% of AEMHR in eight, 5-minute stages. At the end of each stage, and having achieved steady-state, heart rates were recorded from each apparatus. After completing the final stage, participants completed a cooldown at 40% of their AEMHR. Post-exercise heart rate and blood pressure were also recorded to ensure full recovery to baseline. There was a strong positive correlation between the Polar® monitor and the ECG during all stages. However, there were not strong correlations for either of the smartphone-based apps at any time point. Although there were weak correlations between the smartphone-based apps and ECG and Polar®, further studies need to be conducted to determine if inaccuracy is due to user error (finger placement, finger temperature, etc.) or the technology behind the apps. PMID:29541341
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Heart rate variability and turbulence in hyperthyroidism before, during, and after treatment.
Osman, Faizel; Franklyn, Jayne A; Daykin, Jacqueline; Chowdhary, Saqib; Holder, Roger L; Sheppard, Michael C; Gammage, Michael D
2004-08-15
Patients with subclinical and treated overt hyperthyroidism have an excess vascular mortality rate. Several symptoms and signs in overt hyperthyroidism suggest abnormality of cardiac autonomic function that may account in part for this excess mortality rate, but few studies have examined cardiac autonomic function in untreated and treated hyperthyroidism. We assessed heart rate turbulence (HRT) and time-domain parameters of heart rate variability in a large, unselected cohort of patients with overt hyperthyroidism referred to our thyroid clinic (n = 259) and compared findings with a group of normal subjects with euthyroidism (n = 440). These measures were also evaluated during antithyroid therapy (when serum-free thyroxine and triiodothyronine concentrations returned to normal but thyrotropin remained suppressed (i.e., subclinical hyperthyroidism, n = 110) and when subjects were rendered clinically and biochemically euthyroid (normal serum thyrotropin, free thyroxine and triiodothyronine concentrations, n = 219). We found that overall measures of heart rate variability and those specific for cardiac vagal modulation were attenuated in patients with overt hyperthyroidism compared with normal subjects; measurements of overall heart rate variability remained low in those with low levels of serum thyrotropin but returned to normal in patients with biochemical euthyroidism. Measurements of HRT (onset and slope) were also decreased in patients with overt hyperthyroidism, but HRT slope returned to normal values with antithyroid treatment. This study is the first to evaluate HRT in overt and treated hyperthyroidism.
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Drug insight: If inhibitors as specific heart-rate-reducing agents.
Borer, Jeffrey S
2004-12-01
Heart rate is determined primarily by spontaneously repeating net inward current carried by sodium ions and potassium ions through hyperpolarization-activated cyclic-nucleotide-gated channels. Within the heart, these channels are found most abundantly in sinoatrial cardiomyocytes. The channels open in response to membrane hyperpolarization, modulated by local cAMP concentrations. They permit activation of the I(f) current, which can be blocked specifically by molecules characterized by linked benzazepinone and benzocyclobutane rings, and which are devoid of effects on cardiac conduction, inotropy or peripheral vascular tone. The resulting heart-rate reduction has been effective in angina prevention in clinical trials involving 4,000 patients, using the prototype I(f) inhibitor, ivabradine. No serious adverse events have been attributed to the treatment; the most prominent side-effect is dose-related, always reversible and often transient visual symptoms that seldom result in voluntary drug discontinuation.
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Heart Rate Changes in Electroacupuncture Treated Polycystic Ovary in Rats.
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.
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Assessment of heart rate variability based on mobile device for planning physical activity
NASA Astrophysics Data System (ADS)
Svirin, I. S.; Epishina, E. V.; Voronin, V. V.; Semenishchev, E. A.; Solodova, E. N.; Nabilskaya, N. V.
2015-05-01
In this paper we present a method for the functional analysis of human heart based on electrocardiography (ECG) signals. The approach using the apparatus of analytical and differential geometry and correlation and regression analysis. ECG contains information on the current condition of the cardiovascular system as well as on the pathological changes in the heart. Mathematical processing of the heart rate variability allows to obtain a great set of mathematical and statistical characteristics. These characteristics of the heart rate are used when solving research problems to study physiological changes that determine functional changes of an individual. The proposed method implemented for up-to-date mobile Android and iOS based devices.
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Heart Rate Variability Responses of a Preterm Infant to Kangaroo Care
McCain, Gail C.; Ludington-Hoe, Susan M.; Swinth, Joan Y.; Hadeed, Anthony J.
2006-01-01
A 35-week old preterm infant's behavior was fussy and restless in the open crib, but he calmed and fell asleep immediately on being placed skin-to-skin on his mother's chest. Heart rate variability (HRV), a noninvasive method to assess the autonomic nervous system's influence on heart rate, was increased with fussy behavior in the open crib and decreased with sleep during kangaroo care (KC). KC produced changes in behavior and HRV that are illustrative of decreasing stress. PMID:16282226
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Effect of microwave radiation on the beating rate of isolated frog hearts
DOE Office of Scientific and Technical Information (OSTI.GOV)
Yee, K.C.; Chou, C.K.; Guy, A.W.
1984-01-01
One hundred and two isolated frog hearts were divided into ten groups and placed individually in a waveguide filled with Ringer's solution and exposed to 2,450-MHz CW radiation at 2 and 8.55 W/kg. Heart rate was recorded using one of the following methods: 3-M KCl glass electrode, ultrasound probe, tension transducer, Ringer's solution glass electrode, and a metal wire inserted in the Ringer's solution electrode. An accelerated decrease of heart rate was observed only in those groups recorded using the 3-M KCl electrode and the metal wire Ringer's solution electrode. No effect was found in the other groups. These resultsmore » indicate that bradycardia in isolated hearts could be caused by electrode artifacts resulting from the intensification of electromagnetic fields.« less
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Heart rate variability measure in breast cancer patients and survivors: A systematic review.
Arab, Claudia; Dias, Daniel Penteado Martins; Barbosa, Renata Thaís de Almeida; Carvalho, Tatiana Dias de; Valenti, Vitor Engrácia; Crocetta, Tânia Brusque; Ferreira, Marcelo; Abreu, Luiz Carlos de; Ferreira, Celso
2016-06-01
In the current study, we aimed to review literature findings showing the clinical importance of cardiac autonomic modulation assessed by heart rate variability analysis in breast cancer (BC) patients and survivors. We conducted a systematic review according to The PRISMA Statement in Medline, Scopus and Web of Science (_-2015) databases. The search was limited to articles in English language, published in peer-reviewed journals, and with adult age samples only (e.g., women, patients, or survivors, diagnosed with BC in any stage). We included observational studies and randomized trials. Detailed heart rate variability analysis (instruments, data collection protocol, and analysis methods) was required. Search terms included autonomic nervous system, heart rate variability, sympathetic and parasympathetic nervous system, autonomic dysfunction, vagal nervous and breast neoplasms, breast cancer and breast tumor. Twelve studies were included in this review. The clinical importance of cardiac autonomic modulation assessed by heart rate variability analysis in BC patients and survivors is demonstrated by association with effects of BC surgery, and treatments, and the adverse effects of surgery and treatments on survivors (e.g., cardiotoxicity, fatigue, and stress). The strength of evidence of included studies is low: small samples size and heterogeneity, presence of confounders, and observational studies design. The heart rate variability analysis could be used as a complementary non-invasive tool for the early diagnosis and better prognosis of autonomic dysfunction, and survival in BC patients. There are many potential clinical applications of heart rate variability analysis in BC patients, and the employment of such approaches could lead to lower impairment of autonomic function in this individuals. Copyright © 2016 Elsevier Ltd. All rights reserved.
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Post-exercise heart-rate recovery correlates to resting heart-rate variability in healthy men.
Molina, Guilherme Eckhardt; Fontana, Keila Elizabeth; Porto, Luiz Guilherme Grossi; Junqueira, Luiz Fernando
2016-12-01
The relationship between post-exercise heart-rate recovery (HRR) and resting cardiac autonomic modulation is an incompletely explored issue. To correlate HRR with resting supine and orthostatic autonomic status. HRR at the 1st, 3th, and 5th min following maximal treadmill exercise were correlated with 5-min time-domain (CV, pNN50 and rMSSD) and frequency-domain (TP, LF, HF, LFn, HFn, and LF/HF ratio) indices of heart-rate variability (HRV) in both supine and standing positions in 31 healthy physically active non-athletes men. Statistical analysis employed non-parametric tests with two-tailed p value set at 5 %. Absolute HRR and Δ %HRR at each post-exercise time did not correlated with HRV in supine position, as well as at 1st min in standing position. At the 3rd min and 5th min, these measures negatively correlated with pNN50, rMSSD, TP, and HF indices, and only in the 5th min, they showed negative correlation with HFn and positive correlation with LF, LFn, and LF/HF ratio in the standing position. Coefficient of HRR (CHRR) at the 1st min negatively correlated with pNN50 and rMSSD and at 3rd and 5th min showed positive correlation with LFn and LF/HF ratio in supine position. With HRV indices in standing position CHRR from the 1st to 5th min showed the same respective negative and positive correlations as the other measures. HRR from the 1st to 5th min post-exercise negatively correlated with parasympathetic modulation in resting orthostatic, but showed no correlation in supine position. At the 3rd and 5th min, a positive correlation with combined sympathetic-parasympathetic modulation in both positions was observed.
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Heart Rate, Stress, and Occupational Noise Exposure among Electronic Waste Recycling Workers
Burns, Katrina N.; Sun, Kan; Fobil, Julius N.; Neitzel, Richard L.
2016-01-01
Electronic waste (e-waste) is a growing occupational and environmental health issue around the globe. E-waste recycling is a green industry of emerging importance, especially in low-and middle-income countries where much of this recycling work is performed, and where many people’s livelihoods depend on this work. The occupational health hazards of e-waste recycling have not been adequately explored. We performed a cross-sectional study of noise exposures, heart rate, and perceived stress among e-waste recycling workers at a large e-waste site in Accra, Ghana. We interviewed 57 workers and continuously monitored their individual noise exposures and heart rates for up to 24 h. More than 40% of workers had noise exposures that exceeded recommended occupational (85 dBA) and community (70 dBA) noise exposure limits, and self-reported hearing difficulties were common. Workers also had moderate to high levels of perceived stress as measured via Cohen’s Perceived Stress Scale, and reported a variety of symptoms that could indicate cardiovascular disease. Noise exposures were moderately and significantly correlated with heart rate (Spearman’s ρ 0.46, p < 0.001). A mixed effects linear regression model indicated that a 1 dB increase in noise exposure was associated with a 0.17 increase in heart rate (p-value = 0.01) even after controlling for work activities, age, smoking, perceived stress, and unfavorable physical working conditions. These findings suggest that occupational and non-occupational noise exposure is associated with elevations in average heart rate, which may in turn predict potential cardiovascular damage. PMID:26797626
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Heart Rate, Stress, and Occupational Noise Exposure among Electronic Waste Recycling Workers.
Burns, Katrina N; Sun, Kan; Fobil, Julius N; Neitzel, Richard L
2016-01-19
Electronic waste (e-waste) is a growing occupational and environmental health issue around the globe. E-waste recycling is a green industry of emerging importance, especially in low-and middle-income countries where much of this recycling work is performed, and where many people's livelihoods depend on this work. The occupational health hazards of e-waste recycling have not been adequately explored. We performed a cross-sectional study of noise exposures, heart rate, and perceived stress among e-waste recycling workers at a large e-waste site in Accra, Ghana. We interviewed 57 workers and continuously monitored their individual noise exposures and heart rates for up to 24 h. More than 40% of workers had noise exposures that exceeded recommended occupational (85 dBA) and community (70 dBA) noise exposure limits, and self-reported hearing difficulties were common. Workers also had moderate to high levels of perceived stress as measured via Cohen's Perceived Stress Scale, and reported a variety of symptoms that could indicate cardiovascular disease. Noise exposures were moderately and significantly correlated with heart rate (Spearman's ρ 0.46, p < 0.001). A mixed effects linear regression model indicated that a 1 dB increase in noise exposure was associated with a 0.17 increase in heart rate (p-value = 0.01) even after controlling for work activities, age, smoking, perceived stress, and unfavorable physical working conditions. These findings suggest that occupational and non-occupational noise exposure is associated with elevations in average heart rate, which may in turn predict potential cardiovascular damage.
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Development of multiscale complexity and multifractality of fetal heart rate variability.
Gierałtowski, Jan; Hoyer, Dirk; Tetschke, Florian; Nowack, Samuel; Schneider, Uwe; Zebrowski, Jan
2013-11-01
During fetal development a complex system grows and coordination over multiple time scales is formed towards an integrated behavior of the organism. Since essential cardiovascular and associated coordination is mediated by the autonomic nervous system (ANS) and the ANS activity is reflected in recordable heart rate patterns, multiscale heart rate analysis is a tool predestined for the diagnosis of prenatal maturation. The analyses over multiple time scales requires sufficiently long data sets while the recordings of fetal heart rate as well as the behavioral states studied are themselves short. Care must be taken that the analysis methods used are appropriate for short data lengths. We investigated multiscale entropy and multifractal scaling exponents from 30 minute recordings of 27 normal fetuses, aged between 23 and 38 weeks of gestational age (WGA) during the quiet state. In multiscale entropy, we found complexity lower than that of non-correlated white noise over all 20 coarse graining time scales investigated. Significant maturation age related complexity increase was strongest expressed at scale 2, both using sample entropy and generalized mutual information as complexity estimates. Multiscale multifractal analysis (MMA) in which the Hurst surface h(q,s) is calculated, where q is the multifractal parameter and s is the scale, was applied to the fetal heart rate data. MMA is a method derived from detrended fluctuation analysis (DFA). We modified the base algorithm of MMA to be applicable for short time series analysis using overlapping data windows and a reduction of the scale range. We looked for such q and s for which the Hurst exponent h(q,s) is most correlated with gestational age. We used this value of the Hurst exponent to predict the gestational age based only on fetal heart rate variability properties. Comparison with the true age of the fetus gave satisfying results (error 2.17±3.29 weeks; p<0.001; R(2)=0.52). In addition, we found that the normally
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Heart-rate variability depression in porcine peritonitis-induced sepsis without organ failure.
Jarkovska, Dagmar; Valesova, Lenka; Chvojka, Jiri; Benes, Jan; Danihel, Vojtech; Sviglerova, Jitka; Nalos, Lukas; Matejovic, Martin; Stengl, Milan
2017-05-01
Depression of heart-rate variability (HRV) in conditions of systemic inflammation has been shown in both patients and experimental animal models and HRV has been suggested as an early indicator of sepsis. The sensitivity of HRV-derived parameters to the severity of sepsis, however, remains unclear. In this study we modified the clinically relevant porcine model of peritonitis-induced sepsis in order to avoid the development of organ failure and to test the sensitivity of HRV to such non-severe conditions. In 11 anesthetized, mechanically ventilated and instrumented domestic pigs of both sexes, sepsis was induced by fecal peritonitis. The dose of feces was adjusted and antibiotic therapy was administered to avoid multiorgan failure. Experimental subjects were screened for 40 h from the induction of sepsis. In all septic animals, sepsis with hyperdynamic circulation and increased plasma levels of inflammatory mediators developed within 12 h from the induction of peritonitis. The sepsis did not progress to multiorgan failure and there was no spontaneous death during the experiment despite a modest requirement for vasopressor therapy in most animals (9/11). A pronounced reduction of HRV and elevation of heart rate developed quickly (within 5 h, time constant of 1.97 ± 0.80 h for HRV parameter TINN) upon the induction of sepsis and were maintained throughout the experiment. The frequency domain analysis revealed a decrease in the high-frequency component. The reduction of HRV parameters and elevation of heart rate preceded sepsis-associated hemodynamic changes by several hours (time constant of 11.28 ± 2.07 h for systemic vascular resistance decline). A pronounced and fast reduction of HRV occurred in the setting of a moderate experimental porcine sepsis without organ failure. Inhibition of parasympathetic cardiac signaling probably represents the main mechanism of HRV reduction in sepsis. The sensitivity of HRV to systemic inflammation may allow
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Augmented baroreflex heart rate gain after moderate-intensity, dynamic exercise
NASA Technical Reports Server (NTRS)
Halliwill, J. R.; Taylor, J. A.; Hartwig, T. D.; Eckberg, D. L.
1996-01-01
The occurrence of a sustained vasodilation and hypotension after acute, dynamic exercise suggests that exercise may alter arterial baroreflex mechanisms. Therefore, we assessed systemic hemodynamics, baroreflex regulation of heart rate, and cardiac vagal tone after 60 min of cycling at 60% peak oxygen consumption in 12 healthy, untrained men and women (ages 21-28 yr). We derived sigmoidal carotid-cardiac baroreflex relations by measurement of R-R interval changes induced by ramped, stepwise, R-wave-triggered changes in external neck pressure from 40 to -65 mmHg. We estimated tonic cardiac vagal control with power spectral analysis of R-R interval variability in the respiratory frequency band (0.2-0.3 Hz) during frequency- and tidal volume-controlled breathing. Both mean arterial pressure and total peripheral resistance were reduced postexercise [pressure: from 86 +/- 2 (mean +/- SE) to 81 +/- 2 mmHg; resistance: from 23 +/- 2 to 16 +/- 1 units; both P < 0.05]. Cardiac output was increased postexercise (from 3.9 +/- 0.3 to 5.5 +/- 0.5 l/min, P < 0.05). Both slope and range of the carotid-cardiac baroreflex relation were increased postexercise (slope: from 4.7 +/- 0.7 to 6.1 +/- 0.9 ms/mmHg; range: from 186 +/- 23 to 238 +/- 30 ms, P < 0.05). Respiratory R-R interval variability (cardiac vagal tone) was not changed at any time after exercise, whereas heart rate and plasma norepinephrine levels were elevated. Thus moderate-intensity, dynamic exercise increases heart rate and cardiac output, reduces peripheral vascular resistance, and augments baroreflex responsiveness. Our data suggest that augmented baroreflex heart rate gain restrains rather than contributes to postexercise hypotension, which appears to be mediated predominately by vasodilation.
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Seebacher, F; Franklin, C E
2001-12-01
During thermoregulation in the bearded dragon Pogona barbata, heart rate when heating is significantly faster than when cooling at any given body temperature (heart rate hysteresis), resulting in faster rates of heating than cooling. However, the mechanisms that control heart rate during heating and cooling are unknown. The aim of this study was to test the hypothesis that changes in cholinergic and adrenergic tone on the heart are responsible for the heart rate hysteresis during heating and cooling in P. barbata. Heating and cooling trials were conducted before and after the administration of atropine, a muscarinic antagonist, and sotalol, a beta-adrenergic antagonist. Cholinergic and beta-adrenergic blockade did not abolish the heart rate hysteresis, as the heart rate during heating was significantly faster than during cooling in all cases. Adrenergic tone was extremely high (92.3 %) at the commencement of heating, and decreased to 30.7 % at the end of the cooling period. Moreover, in four lizards there was an instantaneous drop in heart rate (up to 15 beats min(-1)) as the heat source was switched off, and this drop in heart rate coincided with either a drop in beta-adrenergic tone or an increase in cholinergic tone. Rates of heating were significantly faster during the cholinergic blockade, and least with a combined cholinergic and beta-adrenergic blockade. The results showed that cholinergic and beta-adrenergic systems are not the only control mechanisms acting on the heart during heating and cooling, but they do have a significant effect on heart rate and on rates of heating and cooling.
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Terminology and Methodology Related to the Use of Heart Rate Responsivity in Infancy Research
ERIC Educational Resources Information Center
Woodcock, James M.
1971-01-01
Methodological problems in measuring and interpreting infantile heart rate reactivity in research are discussed. Various ways of describing cardiac activity are listed. Attention is given to the relationship between resting state and heart rate responsivity. (Author/WY)
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Heart-rate variability and precompetitive anxiety in swimmers.
Cervantes Blásquez, Julio César; Rodas Font, Gil; Capdevila Ortís, Lluís
2009-11-01
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
swimmers (6 women and 4 men) was obtained by comparing baseline training condition (TC) with competition condition (CC). Self-evaluation of precompetitive somatic anxiety measured by CSAI-2 showed significant increase from the TC to CC. Analysis showed that during higher precompetitive anxiety level, a significant reduction in the timing (RMSSD), frequency (HFms2 and HFnu) and Poincaré plot (SD1) of heart-rate variability was observed, and a significant increase in the low frequency to high frequency ratio (LF/HF %). The results indicate a shift towards sympathetic predominance as a result of parasympathetic withdrawal. Our results provide an HRV analysis in a valid, useful and non-invasive way to evaluate the change of sympathovagal balance in presence of precompetitive stress. -
Smartphone-based photoplethysmographic imaging for heart rate monitoring.
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.
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SVM-Based Spectral Analysis for Heart Rate from Multi-Channel WPPG Sensor Signals.
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.
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The Use of Heart Rate Monitors in Physical Education
ERIC Educational Resources Information Center
Nichols, Randall; Davis, Kathryn L.; McCord, Tim; Schmidt, Dave; Slezak, Alex M.
2009-01-01
The ever-rising rate of obesity and the need for increased physical activity for young children is well documented. Data suggests that today's youth are not participating in enough quality health-enhancing physical activity either in or outside of school. Heart rate monitors have been used by adult exercisers for many years to monitor and assess…
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Exposure to wood smoke increases arterial stiffness and decreases heart rate variability in humans
2013-01-01
Background Emissions from biomass combustion are a major source of indoor and outdoor air pollution, and are estimated to cause millions of premature deaths worldwide annually. Whilst adverse respiratory health effects of biomass exposure are well established, less is known about its effects on the cardiovascular system. In this study we assessed the effect of exposure to wood smoke on heart rate, blood pressure, central arterial stiffness and heart rate variability in otherwise healthy persons. Methods Fourteen healthy non-smoking subjects participated in a randomized, double-blind crossover study. Subjects were exposed to dilute wood smoke (mean particle concentration of 314±38 μg/m3) or filtered air for three hours during intermittent exercise. Heart rate, blood pressure, central arterial stiffness and heart rate variability were measured at baseline and for one hour post-exposure. Results Central arterial stiffness, measured as augmentation index, augmentation pressure and pulse wave velocity, was higher after wood smoke exposure as compared to filtered air (p < 0.01 for all), and heart rate was increased (p < 0.01) although there was no effect on blood pressure. Heart rate variability (SDNN, RMSSD and pNN50; p = 0.003, p < 0.001 and p < 0.001 respectively) was decreased one hour following exposure to wood smoke compared to filtered air. Conclusions Acute exposure to wood smoke as a model of exposure to biomass combustion is associated with an immediate increase in central arterial stiffness and a simultaneous reduction in heart rate variability. As biomass is used for cooking and heating by a large fraction of the global population and is currently advocated as a sustainable alternative energy source, further studies are required to establish its likely impact on cardiovascular disease. Trial registration ClinicalTrials.gov, NCT01488500 PMID:23742058
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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.
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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.
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Does Mckuer's Law Hold for Heart Rate Control via Biofeedback Display?
NASA Technical Reports Server (NTRS)
Courter, B. J.; Jex, H. R.
1984-01-01
Some persons can control their pulse rate with the aid of a biofeedback display. If the biofeedback display is modified to show the error between a command pulse-rate and the measured rate, a compensatory (error correcting) heart rate tracking control loop can be created. The dynamic response characteristics of this control loop when subjected to step and quasi-random disturbances were measured. The control loop includes a beat-to-beat cardiotachmeter differenced with a forcing function from a quasi-random input generator; the resulting error pulse-rate is displayed as feedback. The subject acts to null the displayed pulse-rate error, thereby closing a compensatory control loop. McRuer's Law should hold for this case. A few subjects already skilled in voluntary pulse-rate control were tested for heart-rate control response. Control-law properties are derived, such as: crossover frequency, stability margins, and closed-loop bandwidth. These are evaluated for a range of forcing functions and for step as well as random disturbances.
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Bounded Kalman filter method for motion-robust, non-contact heart rate estimation
Prakash, Sakthi Kumar Arul; Tucker, Conrad S.
2018-01-01
The authors of this work present a real-time measurement of heart rate across different lighting conditions and motion categories. This is an advancement over existing remote Photo Plethysmography (rPPG) methods that require a static, controlled environment for heart rate detection, making them impractical for real-world scenarios wherein a patient may be in motion, or remotely connected to a healthcare provider through telehealth technologies. The algorithm aims to minimize motion artifacts such as blurring and noise due to head movements (uniform, random) by employing i) a blur identification and denoising algorithm for each frame and ii) a bounded Kalman filter technique for motion estimation and feature tracking. A case study is presented that demonstrates the feasibility of the algorithm in non-contact estimation of the pulse rate of subjects performing everyday head and body movements. The method in this paper outperforms state of the art rPPG methods in heart rate detection, as revealed by the benchmarked results. PMID:29552419
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Sleep-mediated heart rate variability after bilateral carotid body tumor resection.
Niemeijer, Nicolasine D; Corssmit, Eleonora P M; Reijntjes, Robert H A M; Lammers, Gert Jan; van Dijk, J Gert; Thijs, Roland D
2015-04-01
The carotid bodies are thought to play an important role in sleep-dependent autonomic changes. Patients who underwent resection of bilateral carotid body tumors have chronically attenuated baroreflex sensitivity. These subjects provide a unique opportunity to investigate the role of the baroreflex during sleep. One-night ambulatory polysomnography (PSG) recording. Participants' homes. Nine patients with bilateral carotid body tumor resection (bCBR) (four women, mean age 50.4 ± 7.2 years) and nine controls matched for age, gender, and body mass index. N/A. Sleep parameters were obtained from PSG. Heart rate (HR) and its variability were calculated using 30-s epochs. In bCBR patients, HR was slightly but not significantly increased during wake and all sleep stages. The effect of sleep on HR was similar for patients and controls. Low frequency (LF) power of the heart rate variability spectrum was significantly lower in bCBR patients in active wakefulness, sleep stage 1 and REM sleep. No differences were found between patients and controls for high frequency (HF) power and the LF/HF ratio. Bilateral carotid body tumor resection (bCBR) is associated with decreased low frequency power during sleep, suggesting impaired baroreflex function. Despite this, sleep-related heart rate changes were similar between bCBR patients and controls. These findings suggest that the effects of sleep on heart rate are predominantly generated through central, non-baroreflex mediated pathways. © 2015 Associated Professional Sleep Societies, LLC.
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Beckers, Paul J; Possemiers, Nadine M; Van Craenenbroeck, Emeline M; Van Berendoncks, An M; Wuyts, Kurt; Vrints, Christiaan J; Conraads, Viviane M
2012-02-01
Exercise training efficiently improves peak oxygen uptake (V˙O2peak) in patients with chronic heart failure. To optimize training-derived benefit, higher exercise intensities are being explored. The correct identification of anaerobic threshold is important to allow safe and effective exercise prescription. During 48 cardiopulmonary exercise tests obtained in patients with chronic heart failure (59.6 ± 11 yrs; left ventricular ejection fraction, 27.9% ± 9%), ventilatory gas analysis findings and lactate measurements were collected. Three technicians independently determined the respiratory compensation point (RCP), the heart rate turning point (HRTP) and the second lactate turning point (LTP2). Thereafter, exercise intensity (target heart rate and workload) was calculated and compared between the three methods applied. Patients had significantly reduced maximal exercise capacity (68% ± 21% of predicted V˙O2peak) and chronotropic incompetence (74% ± 7% of predicted peak heart rate). Heart rate, workload, and V˙O2 at HRTP and at RCP were not different, but at LTP2, these parameters were significantly (P < 0.0001) higher. Mean target heart rate and target workload calculated using the LTP2 were 5% and 12% higher compared with those calculated using HRTP and RCP, respectively. The calculation of target heart rate based on LTP2 was 5% and 10% higher in 12 of 48 (25%) and 6 of 48 (12.5%) patients, respectively, compared with the other two methods. In patients with chronic heart failure, RCP and HRTP, determined during cardiopulmonary exercise tests, precede the occurrence of LTP2. Target heart rates and workloads used to prescribe tailored exercise training in patients with chronic heart failure based on LTP2 are significantly higher than those derived from HRTP and RCP.
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Changes in heart rate variability during the induction and decay of heat acclimation.
Flouris, Andreas D; Poirier, Martin P; Bravi, Andrea; Wright-Beatty, Heather E; Herry, Christophe; Seely, Andrew J; Kenny, Glen P
2014-10-01
We evaluated the changes in core temperature, heart rate, and heart rate variability (HRV) during the induction and decay of heat acclimation. Ten males (23 ± 3 years; 79.5 ± 3.5 kg; 15.2 ± 4.5 percent body fat; 51.13 ± 4.61 mLO(2)∙kg(-1)∙min(-1) peak oxygen uptake) underwent a 14-day heat acclimation protocol comprising of 90-min cycling at ~50 % peak oxygen uptake at 40 °C and ~20 % relative humidity. Core temperature, heart rate, and 102 HRV measures were recorded during a heat tolerance test conducted at baseline (day 0) and at the end of the induction (day 14) and decay (day 28) phases. Heat acclimation resulted in significantly reduced core temperature [rectal (χ (2) = 1298.14, p < 0.001); esophageal (χ (2) = 1069.88, p < 0.001)] and heart rate (χ (2) = 1230.17, p < 0.001). Following the decay phase, 26, 40, and 60 % of the heat acclimation-induced reductions in rectal temperature, esophageal temperature, and heart rate, respectively, were lost. Heat acclimation was accompanied by profound and broad changes in HRV: at the end of the induction phase, 75 of the 102 variability measures computed were significantly different (p < 0.001), compared to only 47 of the 102 at the end of the decay phase. Heat acclimation is accompanied by reduced core temperature, significant bradycardia, and marked alterations in HRV, which we interpret as being related to vagal dominance. The observed changes in core temperature persist for at least 2 weeks of non-exposure to heat, while the changes in heart rate and HRV decay faster and are only partly evident after 2 weeks of non-exposure to heat.
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Importance of heart rate during exercise for response to cardiac resynchronization therapy.
Maass, Alexander H; Buck, Sandra; Nieuwland, Wybe; Brügemann, Johan; van Veldhuisen, Dirk J; Van Gelder, Isabelle C
2009-07-01
Cardiac resynchronization therapy (CRT) is an established therapy for patients with severe heart failure and mechanical dyssynchrony. Response is only achieved in 60-70% of patients. To study exercise-related factors predicting response to CRT. We retrospectively examined consecutive patients in whom a CRT device was implanted. All underwent cardiopulmonary exercise testing prior to implantation and after 6 months. The occurrence of chronotropic incompetence and heart rates exceeding the upper rate of the device, thereby compromising biventricular stimulation, was studied. Response was defined as a decrease in LVESV of 10% or more after 6 months. We included 144 patients. After 6 months 86 (60%) patients were responders. Peak VO2 significantly increased in responders. Chronotropic incompetence was more frequently seen in nonresponders (21 [36%] vs 9 [10%], P = 0.03), mostly in patients in SR. At moderate exercise, defined as 25% of the maximal exercise tolerance, that is, comparable to daily life exercise, nonresponders more frequently went above the upper rate of the device (13 [22%] vs 2 [3%], P < 0.0001), most of whom were patients in permanent AF. Multivariate analysis revealed heart rates not exceeding the upper rate of the device during moderate exercise (OR 15.8 [3.3-76.5], P = 0.001) and nonischemic cardiomyopathy (OR 2.4 [1.0-5.7], P = 0.04) as predictive for response. Heart rate exceeding the upper rate during moderate exercise is an independent predictor for nonresponse to CRT in patients with AF, whereas chronotropic incompetence is a predictor for patients in SR.
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Impact of space weather on human heart rate during the years 2011-2013
NASA Astrophysics Data System (ADS)
Galata, E.; Ioannidou, S.; Papailiou, M.; Mavromichalaki, H.; Paravolidakis, K.; Kouremeti, M.; Rentifis, L.; Simantirakis, E.; Trachanas, K.
2017-08-01
During the last years a possible link between different levels of solar and geomagnetic disturbances and human physiological parameters is suggested by several published studies. In this work the examination of the potential association between heart rate variations and specific space weather activities was performed. A total of 482 individuals treated at Hippocratio General Hospital in Athens, the Cardiology clinics of Nikaia General Hospital in Piraeus and the Heraklion University Hospital in Crete, Greece, were assessed from July 2011 to April 2013. The heart rate of the individuals was recorded by a Holter monitor on a n hourly basis, while the hourly variations of the cosmic ray intensity measured by the Neutron Monitor Station of the Athens University and of the geomagnetic index Dst provided by the Kyoto Observatory were used. The ANalysis Of VAriance (ANOVA) and the Multiple Linear Regression analysis were used for analysis of these data. A statistically significant effect of both cosmic rays and geomagnetic activity on heart rate was observed, which may indicate that changes in space weather could be linked to heart rate variations.
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Oh, Myung Ok; Kim, Young Jeoum; Baek, Cho Hee; Kim, Ju Hee; Park, No Mi; Yu, Mi Jeong; Song, Han Sol
2016-06-01
The purpose of this cross-over experimental study was to examine effects of music intervention on maternal anxiety, fetal heart rate pattern and testing time during non-stress tests (NST) for antenatal fetal assessment. Sixty pregnant women within 28 to 40 gestational weeks were randomly assigned to either the experimental group (n=30) or control group (n=30). Music intervention was provided to pregnant women in the experimental group during NST. Degree of maternal anxiety and fetal heart rate pattern were our primary outcomes. State-trait anxiety inventory, blood pressure, pulse rate, and changes in peripheral skin temperature were assessed to determine the degree of maternal anxiety. Baseline fetal heart rate, frequency of acceleration in fetal heart rate, fetal movement test and testing time for reactive NST were assessed to measure the fetal heart rate pattern. The experimental group showed significantly lower scores in state anxiety than the control group. There were no significant differences in systolic blood pressure and pulse rate between the two groups. Baseline fetal heart rate was significantly lower in the experimental group than in the control group. Frequency of acceleration in fetal heart rate was significantly increased in the experimental group compared to the control group. There were no significant differences in fetal movement and testing time for reactive NST between the two groups. Present results suggest that music intervention could be an effective nursing intervention for alel viating anxiety during non-stress test.
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Cardio-pulmonary fitness test by ultra-short heart rate variability.
Aslani, Arsalan; Aslani, Amir; Kheirkhah, Jalal; Sobhani, Vahid
2011-10-01
It is known that exercise induces cardio-respiratory autonomic modulation. The aim of this study was to assess the cardio-pulmonary fitness by ultra-short heart rate variability. Study population was divided into 3 groups: Group-1 (n = 40) consisted of military sports man. Group-2 (n = 40) were healthy age-matched sedentary male subjects with normal body mass index [BMI = 19 - 25 kg/m(2)). Group-3 (n = 40) were healthy age-matched obese male subjects [BMI > 29 kg/m(2)). Standard deviation of normal-to-normal QRS intervals (SDNN) was recorded over 15 minutes. Bruce protocol treadmill test was used; and, maximum oxygen consumption (VO(2)max) was calculated. WHEN THE STUDY POPULATION WAS DIVIDED INTO QUARTILES OF SDNN (FIRST QUARTILE: < 60 msec; second quartile: > 60 and < 100 msec; third quartile: > 100 and <140 msec; and fourth quartile: >140 msec), progressive increase was found in VO(2)max; and, SDNN was significantly linked with estimated VO(2)max. In conclusion, the results of this study demonstrate that exercise training improves cardio-respiratory autonomic function (and increases heart rate variability). Improvement in cardio-respiratory autonomic function seems to translate into a lower rate of long term mortality. Ultra-short heart rate variability is a simple cardio-pulmonary fitness test which just requires 15 minutes, and involves no exercise such as in the treadmill or cycle test.
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Neonatal heart rate prediction.
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.
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Making the Most of the "Daphnia" Heart Rate Lab: Optimizing the Use of Ethanol, Nicotine & Caffeine
ERIC Educational Resources Information Center
Corotto, Frank; Ceballos, Darrel; Lee, Adam; Vinson, Lindsey
2010-01-01
Students commonly test the effects of chemical agents on the heart rate of the crustacean "Daphnia" magna, but the procedure has never been optimized. We determined the effects of three concentrations of ethanol, nicotine, and caffeine and of a control solution on heart rate in "Daphnia." Ethanol at 5% and 10% (v/v) reduced mean heart rate to…
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Molecular Mechanisms of Increased Heart Rate in Shenxianshengmai-treated Bradycardia Rabbits.
Liu, Zhou-Ying; Huang, Jian; Liu, Na-Na; Zheng, Min; Zhao, Tao; Zhao, Bu-Chang; Wang, Yi-Min; Pu, Jie-Lin
2017-01-20
The molecular mechanisms of Shenxianshengmai (SXSM), a traditional Chinese medicine, on bradycardia have been incompletely understood. The study tried to investigate the gene expression profile and proteomics of bradycardia rabbits' hearts after SXSM treatment. Twenty-four adult rabbits were randomly assigned in four groups: sham, model, model plus SXSM treatment, and sham plus SXSM treatment groups. Heart rate was recorded in all rabbits. Then, total RNA of atria and proteins of ventricle were isolated and quantified, respectively. Gene expression profiling was conducted by gene expression chip, and quantitative real-time reverse transcription-polymerase chain reaction (RT-PCR) was performed to confirm the results of gene expression chip. We used isobaric tags for elative and absolute quantitation and Western blotting to identify altered proteins after SXSM treatment. There was a constant decrease in the mean heart rate (32%, from 238 ± 6 beats/min to 149 ± 12 beats/min) after six weeks in model compared with that in sham group. This effect was partially reversed by 4-week SXSM treatment. Complementary DNA microarray demonstrated that the increased acetylcholinesterase and reduced nicotinic receptor were take responsibility for the increased heart rate. In addition, proteins involved in calcium handling and signaling were affected by SXSM treatment. Real-time RT-PCR verified the results from gene chip. Results from proteomics demonstrated that SXSM enhanced oxidative phosphorylation and tricarboxylic acid (TCA) cycle in ventricular myocardium to improve ATP generation. Long-term SXSM stimulates sympathetic transmission by increasing the expression of acetylcholinesterase and reduces the expression of nicotinic receptor to increase heart rate. SXSM also restored the calcium handling genes and altered genes involved in signaling. In addition, SXSM improves the ATP supply of ventricular myocardium by increasing proteins involved in TCA cycle and oxidation
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Molecular Mechanisms of Increased Heart Rate in Shenxianshengmai-treated Bradycardia Rabbits
Liu, Zhou-Ying; Huang, Jian; Liu, Na-Na; Zheng, Min; Zhao, Tao; Zhao, Bu-Chang; Wang, Yi-Min; Pu, Jie-Lin
2017-01-01
Background: The molecular mechanisms of Shenxianshengmai (SXSM), a traditional Chinese medicine, on bradycardia have been incompletely understood. The study tried to investigate the gene expression profile and proteomics of bradycardia rabbits’ hearts after SXSM treatment. Methods: Twenty-four adult rabbits were randomly assigned in four groups: sham, model, model plus SXSM treatment, and sham plus SXSM treatment groups. Heart rate was recorded in all rabbits. Then, total RNA of atria and proteins of ventricle were isolated and quantified, respectively. Gene expression profiling was conducted by gene expression chip, and quantitative real-time reverse transcription-polymerase chain reaction (RT-PCR) was performed to confirm the results of gene expression chip. We used isobaric tags for elative and absolute quantitation and Western blotting to identify altered proteins after SXSM treatment. Results: There was a constant decrease in the mean heart rate (32%, from 238 ± 6 beats/min to 149 ± 12 beats/min) after six weeks in model compared with that in sham group. This effect was partially reversed by 4-week SXSM treatment. Complementary DNA microarray demonstrated that the increased acetylcholinesterase and reduced nicotinic receptor were take responsibility for the increased heart rate. In addition, proteins involved in calcium handling and signaling were affected by SXSM treatment. Real-time RT-PCR verified the results from gene chip. Results from proteomics demonstrated that SXSM enhanced oxidative phosphorylation and tricarboxylic acid (TCA) cycle in ventricular myocardium to improve ATP generation. Conclusions: Long-term SXSM stimulates sympathetic transmission by increasing the expression of acetylcholinesterase and reduces the expression of nicotinic receptor to increase heart rate. SXSM also restored the calcium handling genes and altered genes involved in signaling. In addition, SXSM improves the ATP supply of ventricular myocardium by increasing proteins
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Antenatal fetal heart rate and "maternal intuition" as predictors of fetal sex.
Genuis, S; Genuis, S K; Chang, W C
1996-06-01
To determine if the antenatal fetal heart rate is a reliable predictor of fetal sex, if there is any correlation between "maternal intuition" and fetal gender, and if maternal intuition favors one sex over the other. Two hundred twelve consecutive maternity patients with singleton gestations underwent a total of 2,261 antepartum visits. Fetal heart rate assessment was carried out between 14 and 41 weeks of gestation. At 32 weeks, participants were asked if they had a strong intuitive feeling regarding the fetal gender. Following birth, data on the infant were recorded, and the information was analyzed. There was no significant difference in the baseline fetal heart rate between male and female fetuses at any recorded gestational age. One hundred ten patients (51.9%) in the sample indicated a strong belief about the sex of their fetuses, with the majority (63.6%) predicting a male. The accuracy of maternal intuition, however, was not significantly different from that of random guessing. In the current era of declining family size, an increased focus on absolute reproductive choice and proliferating reproductive technological services, prenatal sex determination and sex selection will continue to provoke increasing attention. Fetal heart rate determination and maternal intuition, however, are not valid predictors of fetal gender.
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O'Neal, Wesley T; Qureshi, Waqas T; Judd, Suzanne E; Meschia, James F; Howard, Virginia J; Howard, George; Soliman, Elsayed Z
2015-12-01
The association between resting heart rate and ischemic stroke remains unclear. To examine the association between resting heart rate and ischemic stroke. A total of 24 730 participants (mean age: 64 ± 9·3 years; 59% women; 41% blacks) from the REasons for Geographic And Racial Differences in Stroke (REGARDS) study who were free of stroke at the time of enrollment (2003-2007) were included in this analysis. Resting heart rate was determined from baseline electrocardiogram data. Heart rate was examined as a continuous variable per 10 bpm increase and also as a categorical variable using tertiles ( <61 bpm, 61 to 70 bpm, and >70 bpm). First-time ischemic stroke events were identified during follow-up and adjudicated by physician review. Over a median follow-up of 7·6 years, a total of 646 ischemic strokes occurred. In a Cox regression model adjusted for socio-demographics, cardiovascular risk factors, and potential confounders, each 10 bpm increase in heart rate was associated with a 10% increase in the risk of ischemic stroke (hazard ratio = 1·10, 95% confidence interval = 1·02, 1·18). In the categorical model, an increased risk of ischemic stroke was observed for heart rates in the middle (hazard ratio = 1·29, 95% confidence interval = 1·06, 1·57) and upper (hazard ratio = 1·37, 95% confidence interval = 1·12, 1·67) tertiles compared with the lower tertile. The results were consistent when the analysis was stratified by age, gender, race, exercise habits, hypertension, and coronary heart disease. In REGARDS, high resting heart rates were associated with an increased risk of ischemic stroke compared with low heart rates. Further research is needed to examine whether interventions aimed to reduce heart rate decrease stroke risk. © 2015 World Stroke Organization.
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Courtney, Rosalba; Cohen, Marc; van Dixhoorn, Jan
2011-01-01
Heart rate variability (HRV) biofeedback is a self-regulation strategy used to improve conditions including asthma, stress, hypertension, and chronic obstructive pulmonary disease. Respiratory muscle function affects hemodynamic influences on respiratory sinus arrhythmia (RSA), and HRV and HRV-biofeedback protocols often include slow abdominal breathing to achieve physiologically optimal patterns of HRV with power spectral distribution concentrated around the 0.1-Hz frequency and large amplitude. It is likely that optimal balanced breathing patterns and ability to entrain heart rhythms to breathing reflect physiological efficiency and resilience and that individuals with dysfunctional breathing patterns may have difficulty voluntarily modulating HRV and RSA. The relationship between breathing movement patterns and HRV, however, has not been investigated. This study examines how individuals' habitual breathing patterns correspond with their ability to optimize HRV and RSA. Breathing pattern was assessed using the Manual Assessment of Respiratory Motion (MARM) and the Hi Lo manual palpation techniques in 83 people with possible dysfunctional breathing before they attempted HRV biofeedback. Mean respiratory rate was also assessed. Subsequently, participants applied a brief 5-minute biofeedback protocol, involving breathing and positive emotional focus, to achieve HRV patterns proposed to reflect physiological "coherence" and entrainment of heart rhythm oscillations to other oscillating body systems. Thoracic-dominant breathing was associated with decreased coherence of HRV (r = -.463, P = .0001). Individuals with paradoxical breathing had the lowest HRV coherence (t(8) = 10.7, P = .001), and the negative relationship between coherence of HRV and extent of thoracic breathing was strongest in this group (r = -.768, P = .03). Dysfunctional breathing patterns are associated with decreased ability to achieve HRV patterns that reflect cardiorespiratory efficiency and
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França da Silva, Anne Kastelianne; Penachini da Costa de Rezende Barbosa, Marianne; Marques Vanderlei, Franciele; Destro Christofaro, Diego Giuliano; Marques Vanderlei, Luiz Carlos
2016-05-01
The use of heart rate variability as a tool capable of discriminating individuals with diabetes mellitus is still little explored, as its use has been limited to comparing those with and without the disease. Thus, the purpose of this study was to verify the use of heart rate variability as a tool for diagnostic and prognostic evaluation in person with diabetes and to identify whether there are cutoff points generated from the use of this tool in these individuals. A search was conducted in the electronic databases MEDLINE, Cochrane Library, Web of Science, EMBASE, and LILACS starting from the oldest records until January 2015, by means of descriptors related to the target condition, evaluated tool, and evaluation method. All the studies were evaluated for methodological quality using the QUADAS-2 instrument. Eight studies were selected. In general, the studies showed that the heart rate variability is useful to discriminate cardiac autonomic neuropathy in person with diabetes, and the sample entropy, SD1/SD2 indices, SDANN, HF, and slope of TFC have better discriminatory power to detect autonomic dysfunction, with sensitivity and specificity values ranging from 72% to 100% and 71% to 97%, respectively. Although there are methodological differences in indices used, in general, this tool demonstrated good sensitivity and specificity and can be used as an additional and/or complementary tool to the conventional autonomic tests, in order to obtain safer and more effective diagnostic, collaborating for better risk stratification conditions of these patients. © 2016 Wiley Periodicals, Inc.
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Compression based entropy estimation of heart rate variability on multiple time scales.
Baumert, Mathias; Voss, Andreas; Javorka, Michal
2013-01-01
Heart rate fluctuates beat by beat in a complex manner. The aim of this study was to develop a framework for entropy assessment of heart rate fluctuations on multiple time scales. We employed the Lempel-Ziv algorithm for lossless data compression to investigate the compressibility of RR interval time series on different time scales, using a coarse-graining procedure. We estimated the entropy of RR interval time series of 20 young and 20 old subjects and also investigated the compressibility of randomly shuffled surrogate RR time series. The original RR time series displayed significantly smaller compression entropy values than randomized RR interval data. The RR interval time series of older subjects showed significantly different entropy characteristics over multiple time scales than those of younger subjects. In conclusion, data compression may be useful approach for multiscale entropy assessment of heart rate variability.
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Turner, J R; Carroll, D; Sims, J; Hewitt, J K; Kelly, K A
1986-01-01
Heart rate was monitored while 22 pairs of young male monozygotic and 29 pairs of young male dizygotic twins were exposed to a video game and a mental arithmetic task. The heart rate reactions of the monozygotic twins showed much greater concordance than those of the dizygotic twins. Analysis of the data for the 102 individuals demonstrated reliable inter-task consistency of heart rate reaction. In addition, comparison of the heart rate reactions of ten pairs of monozygotic and ten pairs of dizygotic twins who had been tested more than a year earlier and their present reactivities revealed impressive temporal consistency.
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Volitional Control of Heart Rate During Exercise Stress.
ERIC Educational Resources Information Center
LeFevers, Victoria A.
Thirty five volunteer college women were divided into three groups to determine if heart rate could be conditioned instrumentally and lowered during exercise stress on the treadmill. The three groups were a) experimental group I, 15 subjects who received instrumental conditioning with visual feedback; b) instrumental group II, 9 subjects who…
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NASA Astrophysics Data System (ADS)
Hughson, R. L.; Shoemaker, J. K.; Blaber, A. P.; Arbeille, Ph.; Zuj, K. A.; Greaves, D. K.
2008-06-01
CCISS is a project to study the cardiovascular and cerebrovascular responses of astronauts before, during and after long-duration (>60-day) stays on the International Space Station. The CCISS experiments consist of three phases that are designed to achieve an integrated examination of components responsible for return of blood to the heart, the pumping of blood from the heart and the distribution to the vascular territories including the brain. In this report the data are obtained from the 24-h monitoring of physical activity (Actiwatch on wrist and ankle) and of heart rate (Holter monitor). The data show clear patterns of change in physical activity from predominantly leg-based on Earth to relatively little activity of the ankles with maintained or increased activity of the wrists on ISS. Both on Earth and on ISS the largest changes in heart rate occur during the periods of leg activity. Average heart rate was changed little during the periods of minimal activity or of sleep in comparisons of Earth with in-flight recording both within the first two weeks of flight and the last two weeks. These data clearly show the importance of monitoring heart rate and physical activity simultaneously and show that attempts to derive indicators of autonomic activity from spectral analysis of heart rate variability should not be performed in the absence of knowledge of both variables.
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Dogs with macroadenomas have lower body temperature and heart rate than dogs with microadenomas.
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 (P<0.01) compared to dogs 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.
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Jahandardoost, Mehdi; Fradet, Guy; Mohammadi, Hadi
2016-03-01
To date, to the best of the authors' knowledge, in almost all of the studies performed around the hemodynamics of bileaflet mechanical heart valves, a heart rate of 70-72 beats/min has been considered. In fact, the heart rate of ~72 beats/min does not represent the entire normal physiological conditions under which the aortic or prosthetic valves function. The heart rates of 120 or 50 beats/min may lead to hemodynamic complications, such as plaque formation and/or thromboembolism in patients. In this study, the hemodynamic performance of the bileaflet mechanical heart valves in a wide range of normal and physiological heart rates, that is, 60-150 beats/min, was studied in the opening phase. The model considered in this study was a St. Jude Medical bileaflet mechanical heart valve with the inner diameter of 27 mm in the aortic position. The hemodynamics of the native valve and the St. Jude Medical valve were studied in a variety of heart rates in the opening phase and the results were carefully compared. The results indicate that peak values of the velocity profile downstream of the valve increase as heart rate increases, as well as the location of the maximum velocity changes with heart rate in the St. Jude Medical valve model. Also, the maximum values of shear stress and wall shear stresses downstream of the valve are proportional to heart rate in both models. Interestingly, the maximum shear stress and wall shear stress values in both models are in the same range when heart rate is <90 beats/min; however, these values significantly increase in the St. Jude Medical valve model when heart rate is >90 beats/min (up to ~40% growth compared to that of the native valve). The findings of this study may be of importance in the hemodynamic performance of bileaflet mechanical heart valves. They may also play an important role in design improvement of conventional prosthetic heart valves and the design of the next generation of prosthetic valves, such as
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Heart-Rate Variability—More than Heart Beats?
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. PMID:28955705
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Heart-Rate Variability-More than Heart Beats?
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.
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Nemati, Shamim; Edwards, Bradley A.; Lee, Joon; Pittman-Polletta, Benjamin; Butler, James P.; Malhotra, Atul
2013-01-01
Aging and disease are accompanied with a reduction of complex variability in the temporal patterns of heart rate. This reduction has been attributed to a break down of the underlying regulatory feedback mechanisms that maintain a homeodynamic state. Previous work has established the utility of entropy as an index of disorder, for quantification of changes in heart rate complexity. However, questions remain regarding the origin of heart rate complexity and the mechanisms involved in its reduction with aging and disease. In this work we use a newly developed technique based on the concept of band-limited transfer entropy to assess the aging-related changes in contribution of respiration and blood pressure to entropy of heart rate at different frequency bands. Noninvasive measurements of heart beat interval, respiration, and systolic blood pressure were recorded from 20 young (21–34 years) and 20 older (68–85 years) healthy adults. Band-limited transfer entropy analysis revealed a reduction in high-frequency contribution of respiration to heart rate complexity (p < 0.001) with normal aging, particularly in men. These results have the potential for dissecting the relative contributions of respiration and blood pressure-related reflexes to heart rate complexity and their degeneration with normal aging. PMID:23811194
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Heart rate time series characteristics for early detection of infections in critically ill patients.
Tambuyzer, T; Guiza, F; Boonen, E; Meersseman, P; Vervenne, H; Hansen, T K; Bjerre, M; Van den Berghe, G; Berckmans, D; Aerts, J M; Meyfroidt, G
2017-04-01
It is difficult to make a distinction between inflammation and infection. Therefore, new strategies are required to allow accurate detection of infection. Here, we hypothesize that we can distinguish infected from non-infected ICU patients based on dynamic features of serum cytokine concentrations and heart rate time series. Serum cytokine profiles and heart rate time series of 39 patients were available for this study. The serum concentration of ten cytokines were measured using blood sampled every 10 min between 2100 and 0600 hours. Heart rate was recorded every minute. Ten metrics were used to extract features from these time series to obtain an accurate classification of infected patients. The predictive power of the metrics derived from the heart rate time series was investigated using decision tree analysis. Finally, logistic regression methods were used to examine whether classification performance improved with inclusion of features derived from the cytokine time series. The AUC of a decision tree based on two heart rate features was 0.88. The model had good calibration with 0.09 Hosmer-Lemeshow p value. There was no significant additional value of adding static cytokine levels or cytokine time series information to the generated decision tree model. The results suggest that heart rate is a better marker for infection than information captured by cytokine time series when the exact stage of infection is not known. The predictive value of (expensive) biomarkers should always be weighed against the routinely monitored data, and such biomarkers have to demonstrate added value.
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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.
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NASA Astrophysics Data System (ADS)
Deglint, Jason; Chung, Audrey G.; Chwyl, Brendan; Amelard, Robert; Kazemzadeh, Farnoud; Wang, Xiao Yu; Clausi, David A.; Wong, Alexander
2016-03-01
Traditional photoplethysmographic imaging (PPGI) systems use the red, green, and blue (RGB) broadband measurements of a consumer digital camera to remotely estimate a patients heart rate; however, these broadband RGB signals are often corrupted by ambient noise, making the extraction of subtle fluctuations indicative of heart rate difficult. Therefore, the use of narrow-band spectral measurements can significantly improve the accuracy. We propose a novel digital spectral demultiplexing (DSD) method to infer narrow-band spectral information from acquired broadband RGB measurements in order to estimate heart rate via the computation of motion- compensated skin erythema fluctuation. Using high-resolution video recordings of human participants, multiple measurement locations are automatically identified on the cheeks of an individual, and motion-compensated broadband reflectance measurements are acquired at each measurement location over time via measurement location tracking. The motion-compensated broadband reflectance measurements are spectrally demultiplexed using a non-linear inverse model based on the spectral sensitivity of the camera's detector. A PPG signal is then computed from the demultiplexed narrow-band spectral information via skin erythema fluctuation analysis, with improved signal-to-noise ratio allowing for reliable remote heart rate measurements. To assess the effectiveness of the proposed system, a set of experiments involving human motion in a front-facing position were performed under ambient lighting conditions. Experimental results indicate that the proposed system achieves robust and accurate heart rate measurements and can provide additional information about the participant beyond the capabilities of traditional PPGI methods.
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NASA Astrophysics Data System (ADS)
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.
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ARTiiFACT: a tool for heart rate artifact processing and heart rate variability analysis.
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.
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Pillai, Indulekha C L; Li, Shen; Romay, Milagros; Lam, Larry; Lu, Yan; Huang, Jie; Dillard, Nathaniel; Zemanova, Marketa; Rubbi, Liudmilla; Wang, Yibin; Lee, Jason; Xia, Ming; Liang, Owen; Xie, Ya-Hong; Pellegrini, Matteo; Lusis, Aldons J; Deb, Arjun
2017-02-02
Mammalian tissues calcify with age and injury. Analogous to bone formation, osteogenic cells are thought to be recruited to the affected tissue and induce mineralization. In the heart, calcification of cardiac muscle leads to conduction system disturbances and is one of the most common pathologies underlying heart blocks. However the cell identity and mechanisms contributing to pathological heart muscle calcification remain unknown. Using lineage tracing, murine models of heart calcification and in vivo transplantation assays, we show that cardiac fibroblasts (CFs) adopt an osteoblast cell-like fate and contribute directly to heart muscle calcification. Small-molecule inhibition of ENPP1, an enzyme that is induced upon injury and regulates bone mineralization, significantly attenuated cardiac calcification. Inhibitors of bone mineralization completely prevented ectopic cardiac calcification and improved post injury heart function. Taken together, these findings highlight the plasticity of fibroblasts in contributing to ectopic calcification and identify pharmacological targets for therapeutic development. Copyright © 2017 Elsevier Inc. All rights reserved.
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Steinberg, Benjamin A; Kim, Sunghee; Thomas, Laine; Fonarow, Gregg C; Gersh, Bernard J; Holmqvist, Fredrik; Hylek, Elaine; Kowey, Peter R; Mahaffey, Kenneth W; Naccarelli, Gerald; Reiffel, James A; Chang, Paul; Peterson, Eric D; Piccini, Jonathan P
2015-09-14
Most patients with atrial fibrillation (AF) require rate control; however, the optimal target heart rate remains under debate. We aimed to assess rate control and subsequent outcomes among patients with permanent AF. We studied 2812 US outpatients with permanent AF in the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation. Resting heart rate was measured longitudinally and used as a time-dependent covariate in multivariable Cox models of all-cause and cause-specific mortality during a median follow-up of 24 months. At baseline, 7.4% (n=207) had resting heart rate <60 beats per minute (bpm), 62% (n=1755) 60 to 79 bpm, 29% (n=817) 80 to 109 bpm, and 1.2% (n=33) ≥110 bpm. Groups did not differ by age, previous cerebrovascular disease, heart failure status, CHA2DS2-VASc scores, renal function, or left ventricular function. There were significant differences in race (P=0.001), sinus node dysfunction (P=0.004), and treatment with calcium-channel blockers (P=0.006) and anticoagulation (P=0.009). In analyses of continuous heart rates, lower heart rate ≤65 bpm was associated with higher all-cause mortality (adjusted hazard ratio [HR], 1.15 per 5-bpm decrease; 95% CI, 1.01 to 1.32; P=0.04). Similarly, increasing heart rate >65 bpm was associated with higher all-cause mortality (adjusted HR, 1.10 per 5-bpm increase; 95% CI, 1.05 to 1.15; P<0.0001). This relationship was consistent across endpoints and in a broader sensitivity analysis of permanent and nonpermanent AF patients. Among patients with permanent AF, there is a J-shaped relationship between heart rate and mortality. These data support current guideline recommendations, and clinical trials are warranted to determine optimal rate control. URL: http://clinicaltrials.gov/. Unique identifier: NCT01165710. © 2015 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.
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Dynamic neural networking as a basis for plasticity in the control of heart rate.
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.
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Heart Rate and Stress in a College Setting
ERIC Educational Resources Information Center
Elwess, Nancy L.; Vogt, F. Daniel
2005-01-01
Conditions producing stress are present in all colleges and universities. In this paper we report on an investigation utilizing heart rate as an indicator of stress in students when participating in activities encountered in a college classroom or laboratory. The activities included presenting an oral report, taking an exam, and participating in a…
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Heart Rate Monitors Promote Physical Education for Children
ERIC Educational Resources Information Center
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…
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Influence of Prolonged Spaceflight on Heart Rate and Oxygen Uptake Kinetics
NASA Astrophysics Data System (ADS)
Hoffmann, U.; Moore, A.; Drescher, U.
2013-02-01
During prolonged spaceflight, physical training is used to minimize cardiovascular deconditioning. Measurement of the kinetics of cardiorespiratory parameters, in particular the kinetic analysis of heart rate, respiratory and muscular oxygen uptake, provides useful information with regard to the efficiency and regulation of the cardiorespiratory system. Practically, oxygen uptake kinetics can only be measured at the lung site (V’O2 resp). The dynamics of V’O2 resp, however, is not identical with the dynamics at the site of interest: skeletal muscle. Eight Astronauts were tested pre- and post-flight using pseudo random binary workload changes between 30 and 80 W. Their kinetic responses of heart rate, respiratory as well as muscular V’O2 kinetics were estimated by using time-series analysis. Statistical analysis revealed that the kinetic responses of respiratory as well as muscular V’O2 kinetics are slowed post-flight than pre-flight. Heart rate seems not to be influenced following flight. The influence of other factors (e. g. astronauts’ exercise training) may impact these parameters and is an area for future studies.
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Heart rate variability: Pre-deployment predictor of post-deployment PTSD symptoms
Pyne, Jeffrey M.; Constans, Joseph I.; Wiederhold, Mark D.; Gibson, Douglas P.; Kimbrell, Timothy; Kramer, Teresa L.; Pitcock, Jeffery A.; Han, Xiaotong; Williams, D. Keith; Chartrand, Don; Gevirtz, Richard N.; Spira, James; Wiederhold, Brenda K.; McCraty, Rollin; McCune, Thomas R.
2017-01-01
Heart rate variability is a physiological measure associated with autonomic nervous system activity. This study hypothesized that lower pre-deployment HRV would be associated with higher post-deployment post-traumatic stress disorder (PTSD) symptoms. Three-hundred-forty-three Army National Guard soldiers enrolled in the Warriors Achieving Resilience (WAR) study were analyzed. The primary outcome was PTSD symptom severity using the PTSD Checklist – Military version (PCL) measured at baseline, 3- and 12-month post-deployment. Heart rate variability predictor variables included: high frequency power (HF) and standard deviation of the normal cardiac inter-beat interval (SDNN). Generalized linear mixed models revealed that the pre-deployment PCL*ln(HF) interaction term was significant (p < 0.0001). Pre-deployment SDNN was not a significant predictor of post-deployment PCL. Covariates included age, pre-deployment PCL, race/ethnicity, marital status, tobacco use, childhood abuse, pre-deployment traumatic brain injury, and previous combat zone deployment. Pre-deployment heart rate variability predicts post-deployment PTSD symptoms in the context of higher pre-deployment PCL scores. PMID:27773678
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Manati, Waheed; Pineau, Julien; Doñate Puertas, Rosa; Morel, Elodie; Quadiri, Timour; Bui-Xuan, Bernard; Chevalier, Philippe
2018-01-03
Strong evidence suggests a causal link between autonomic disturbances and ventricular arrhythmias. However, the mechanisms underlying the antiarrhythmic effect of vagal stimulation are poorly understood. The vagal antiarrhythmic effect might be modulated by a decrease in heart rate. the proximal anterior interventricular artery was occluded in 16 pigs by clamping under general anaesthesia. Group 1: heart rates remained spontaneous (n = 6; 12 occlusions); Group 2: heart rates were fixed at 190 beats per minute (bpm) with atrial electrical stimulation (n = 10; 20 occlusions). Each pig received two occlusions, 30 min apart, one without and one with vagal stimulation (10 Hz, 2 ms, 5-20 mA). The antiarrhythmic effect of vagal activation was defined as the time to the appearance of ventricular fibrillation (VF) after occlusion. In Group 1, vagal stimulation triggered a significant decrease in basal heart rate (132 ± 4 vs. 110 ± 17 bpm, p < 0.05), and delayed the time to VF after coronary occlusion (1102 ± 85 vs. 925 ± 41 s, p < 0.05). In Group 2, vagal stimulation did not modify the time to VF (103 ± 39 vs. 91 ± 20 s). Analyses revealed that heart rate and the time to VF were positively linearly related. Maintaining a constant heart rate with atrial electrical stimulation in pigs prevented vagal stimulation from modifying the time to VF after acute coronary occlusion.
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Curilem Gatica, Cristian; Almagià Flores, Atilio; Yuing Farías, Tuillang; Rodríguez Rodríguez, Fernando
2014-07-01
Body composition is a non-invasive method, which gives us information about the distribution of tissues in the body structure, it is also an indicator of the risk of mortality in patients with chronic obstructive pulmonary disease. The heart rate variability is a technique that gives us information of autonomic physiological condition, being recognized as an indicator which is decreased in a number of diseases. The purpose of this study was to assess body composition and heart rate variability. The methodology used is that of Debora Kerr (1988) endorsed by the International Society for advances in Cineantropometría for body composition and heart rate variability of the guidelines described by the American Heart Association (1996). Roscraff equipment, caliper Slimguide and watch Polar RS 800CX was used. , BMI 26.7 ± 3.9 kg / m²; Muscle Mass 26.1 ± 6.3 kg ; Bone Mass 1.3 kg ± 8.1 76 ± 9.9 years Age : 14 candidates for pulmonary rehabilitation patients were evaluated , Adipose mass 16.4 ± 3.6 kg ; FEV1 54 ± 14%. Increased waist circumference and waist hip ratio was associated with a lower overall heart rate variability. The bone component was positively related to the variability of heart rate and patients with higher forced expiratory volume in one second had lower high frequency component in heart rate variability. In these patients, the heart rate variability is reduced globally and is associated with cardiovascular risk parameters. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.
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Eppinga, Ruben N; Hagemeijer, Yanick; Burgess, Stephen; Hinds, David A; Stefansson, Kari; Gudbjartsson, Daniel F; van Veldhuisen, Dirk J; Munroe, Patricia B; Verweij, Niek; van der Harst, Pim
2016-12-01
Resting heart rate is a heritable trait correlated with life span. Little is known about the genetic contribution to resting heart rate and its relationship with mortality. We performed a genome-wide association discovery and replication analysis starting with 19.9 million genetic variants and studying up to 265,046 individuals to identify 64 loci associated with resting heart rate (P < 5 × 10 -8 ); 46 of these were novel. We then used the genetic variants identified to study the association between resting heart rate and all-cause mortality. We observed that a genetically predicted resting heart rate increase of 5 beats per minute was associated with a 20% increase in mortality risk (hazard ratio 1.20, 95% confidence interval 1.11-1.28, P = 8.20 × 10 -7 ) translating to a reduction in life expectancy of 2.9 years for males and 2.6 years for females. Our findings provide evidence for shared genetic predictors of resting heart rate and all-cause mortality.
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Kontosic, I; Vukelić, M; Pancić, M; Kunisek, J
1994-12-01
Physical work load was estimated in a female conveyor-belt worker in a bottling plant. Estimation was based on continuous measurement and on calculation of average heart rate values in three-minute and one-hour periods and during the total measuring period. The thermal component of the heart rate was calculated by means of the corrected effective temperature, for the one-hour periods. The average heart rate at rest was also determined. The work component of the heart rate was calculated by subtraction of the resting heart rate and the heart rate measured at 50 W, using a regression equation. The average estimated gross energy expenditure during the work was 9.6 +/- 1.3 kJ/min corresponding to the category of light industrial work. The average estimated oxygen uptake was 0.42 +/- 0.06 L/min. The average performed mechanical work was 12.2 +/- 4.2 W, i.e. the energy expenditure was 8.3 +/- 1.5%.
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Grigg, G C; Seebacher, F
1999-01-01
The discovery that changes in heart rate and blood flow allow some reptiles to heat faster than they cool has become a central paradigm in our understanding of reptilian thermoregulation. However, this hysteresis in heart rate has been demonstrated only in simplistic laboratory heating and cooling trials, leaving its functional significance in free-ranging animals unproven. To test the validity of this paradigm, we measured heart rate and body temperature (Tb) in undisturbed, free-ranging bearded dragons (Pogona barbata), the species in which this phenomenon was first described. Our field data confirmed the paradigm and we found that heart rate during heating usually exceeded heart rate during cooling at any Tb. Importantly, however, we discovered that heart rate was proportionally faster in cool lizards whose Tb was still well below the 'preferred Tb range' compared to lizards whose Tb was already close to it. Similarly, heart rate during cooling was proportionally slower the warmer the lizard and the greater its cooling potential compared to lizards whose Tb was already near minimum operative temperature. Further, we predicted that, if heart rate hysteresis has functional significance, a 'reverse hysteresis' pattern should be observable when lizards risked overheating. This was indeed the case and, during heating on those occasions when Tb reached very high levels (> 40 degrees C), heart rate was significantly lower than heart rate during the immediately following cooling phase. These results demonstrate that physiological control of thermoregulation in reptiles is more complex than has been previously recognized. PMID:10418165
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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.
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Arslan, Erşan; Aras, Dicle
2016-01-01
[Purpose] The aim of this study was to compare the body composition, heart rate variability, and aerobic and anaerobic performance between competitive cyclists and triathletes. [Subjects] Six cyclists and eight triathletes with experience in competitions voluntarily participated in this study. [Methods] The subjects’ body composition was measured with an anthropometric tape and skinfold caliper. Maximal oxygen consumption and maximum heart rate were determined using the incremental treadmill test. Heart rate variability was measured by 7 min electrocardiographic recording. The Wingate test was conducted to determine anaerobic physical performance. [Results] There were significant differences in minimum power and relative minimum power between the triathletes and cyclists. Anthropometric characteristics and heart rate variability responses were similar among the triathletes and cyclists. However, triathletes had higher maximal oxygen consumption and lower resting heart rates. This study demonstrated that athletes in both sports have similar body composition and aerobic performance characteristics. PMID:27190476
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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.
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Heart Disease Death Rates Among Blacks and Whites Aged ≥35 Years — United States, 1968–2015
Van Dyke, Miriam; Greer, Sophia; Odom, Erika; Schieb, Linda; Vaughan, Adam; Kramer, Michael; Casper, Michele
2018-01-01
Problem/Condition Heart disease is the leading cause of death in the United States. In 2015, heart disease accounted for approximately 630,000 deaths, representing one in four deaths in the United States. Although heart disease death rates decreased 68% for the total population from 1968 to 2015, marked disparities in decreases exist by race and state. Period Covered 1968–2015. Description of System The National Vital Statistics System (NVSS) data on deaths in the United States were abstracted for heart disease using diagnosis codes from the eighth, ninth, and tenth revisions of the International Classification of Diseases (ICD-8, ICD-9, and ICD-10) for 1968–2015. Population estimates were obtained from NVSS files. National and state-specific heart disease death rates for the total population and by race for adults aged ≥35 years were calculated for 1968–2015. National and state-specific black-white heart disease mortality ratios also were calculated. Death rates were age standardized to the 2000 U.S. standard population. Joinpoint regression was used to perform time trend analyses. Results From 1968 to 2015, heart disease death rates decreased for the total U.S. population among adults aged ≥35 years, from 1,034.5 to 327.2 per 100,000 population, respectively, with variations in the magnitude of decreases by race and state. Rates decreased for the total population an average of 2.4% per year, with greater average decreases among whites (2.4% per year) than blacks (2.2% per year). At the national level, heart disease death rates for blacks and whites were similar at the start of the study period (1968) but began to diverge in the late 1970s, when rates for blacks plateaued while rates for whites continued to decrease. Heart disease death rates among blacks remained higher than among whites for the remainder of the study period. Nationwide, the black-white ratio of heart disease death rates increased from 1.04 in 1968 to 1.21 in 2015, with large increases
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2007-01-01
harp music on heart rate, mean blood pressure, respiratory rate, and body temperature in the African green monkey. Journal of Medical Primatology 36:95...13. SUPPLEMENTARY NOTES 14. ABSTRACT Background: The effectiveness of recorded harp music as a tool for relaxation for nonhuman primates (NHP) is...Chlorocebus aethiops). After post-surgical recovery, animals were exposed to recorded harp music . Telemetry data were collected on heart rate, mean
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Fetal heart rate changes associated with general anesthesia.
Fedorkow, D M; Stewart, T J; Parboosingh, J
1989-07-01
Decreased fetal heart rate variability was noted 90 seconds after the induction of general anesthesia with sodium thiopentone and fentanyl in a patient undergoing basket extraction of a renal calculus at 30 weeks' gestation. The fetal sleep pattern lasted for 105 minutes after the anesthetic was discontinued, 45 minutes after the mother was fully awake.
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Neural control of heart rate: the role of neuronal networking.
Kember, G; Armour, J A; Zamir, M
2011-05-21
Neural control of heart rate, particularly its sympathetic component, is generally thought to reside primarily in the central nervous system, though accumulating evidence suggests that intrathoracic extracardiac and intrinsic cardiac ganglia are also involved. We propose an integrated model in which the control of heart rate is achieved via three neuronal "levels" representing three control centers instead of the conventional one. Most importantly, in this model control is effected through networking between neuronal populations within and among these layers. The results obtained indicate that networking serves to process demands for systemic blood flow before transducing them to cardiac motor neurons. This provides the heart with a measure of protection against the possibility of "overdrive" implied by the currently held centrally driven system. The results also show that localized networking instabilities can lead to sporadic low frequency oscillations that have the characteristics of the well-known Mayer waves. The sporadic nature of Mayer waves has been unexplained so far and is of particular interest in clinical diagnosis. Copyright © 2011 Elsevier Ltd. All rights reserved.
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Heart rate deceleration runs for postinfarction risk prediction.
Guzik, Przemyslaw; Piskorski, Jaroslaw; Barthel, Petra; Bauer, Axel; Müller, Alexander; Junk, Nadine; Ulm, Kurt; Malik, Marek; Schmidt, Georg
2012-01-01
A method for counting episodes of uninterrupted beat-to-beat heart rate decelerations was developed. The method was set up and evaluated using 24-hour electrocardiogram Holter recordings of 1455 (training sample) and 946 (validation sample) postinfarction patients. During a median follow-up of 24 months, 70, 46, and 19 patients of the training sample suffered from total, cardiac, and sudden cardiac mortality, respectively. In the validation sample, these numbers were 39, 25, and 15. Episodes of consecutive beat-to-beat heart rate decelerations (deceleration runs [DRs]) were characterized by their length. Deceleration runs of 2 to 10 cycles were significantly less frequent in nonsurvivors. Multivariate model of DRs of 2, 4, and 8 cycles identified low-, intermediate-, and high-risk groups. In these groups of the training sample, the total mortalities were 1.8%, 6.1%, and 24%, respectively. In the validation sample, these numbers were 1.8%, 4.1%, and 21.9%. Infrequent DRs during 24-hour Holter indicate high risk of postinfarction mortality. Copyright © 2012 Elsevier Inc. All rights reserved.
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Complexity analysis of fetal heart rate preceding intrauterine demise.
Schnettler, William T; Goldberger, Ary L; Ralston, Steven J; Costa, Madalena
2016-08-01
Visual non-stress test interpretation lacks the optimal specificity and observer-agreement of an ideal screening tool for intrauterine fetal demise (IUFD) syndrome prevention. Computational methods based on traditional heart rate variability have also been of limited value. Complexity analysis probes properties of the dynamics of physiologic signals that are otherwise not accessible and, therefore, might be useful in this context. To explore the association between fetal heart rate (FHR) complexity analysis and subsequent IUFD. Our specific hypothesis is that the complexity of the fetal heart rate dynamics is lower in the IUFD group compared with controls. This case-control study utilized cases of IUFD at a single tertiary-care center among singleton pregnancies with at least 10min of continuous electronic FHR monitoring on at least 2 weekly occasions in the 3 weeks immediately prior to fetal demise. Controls delivered a live singleton beyond 35 weeks' gestation and were matched to cases by gestational age, testing indication, and maternal age in a 3:1 ratio. FHR data was analyzed using the multiscale entropy (MSE) method to derive their complexity index. In addition, pNNx, a measure of short-term heart rate variability, which in adults is ascribable primarily to cardiac vagal tone modulation, was also computed. 211 IUFDs occurred during the 9-year period of review, but only 6 met inclusion criteria. The median gestational age at the time of IUFD was 35.5 weeks. Three controls were matched to each case for a total of 24 subjects, and 87 FHR tracings were included for analysis. The median gestational age at the first fetal heart rate tracing was similar between groups (median [1st-3rd quartiles] weeks: IUFD cases: 34.7 (34.4-36.2); controls: 35.3 (34.4-36.1); p=.94). The median complexity of the cases' tracings was significantly less than the controls' (12.44 [8.9-16.77] vs. 17.82 [15.21-22.17]; p<.0001). Furthermore, the cases' median complexity decreased as
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Girotra, Saket; Kitzman, Dalane W.; Kop, Willem J.; Stein, Phyllis K.; Gottdiener, John S.; Mukamal, Kenneth J.
2012-01-01
OBJECTIVES To determine the relationship between heart rate response during low-grade physical exertion (six-minute walk) with mortality and adverse cardiovascular outcomes in the elderly. METHODS Participants in the Cardiovascular Health Study, who completed a six-minute walk test, were included. We used delta heart rate (difference between post-walk heart rate and resting heart rate) as a measure of chronotropic response and examined its association with 1) all-cause mortality and 2) incident coronary heart disease (CHD) event, using multivariable Cox regression models. RESULTS We included 2224 participants (mean age 77±4 years; 60% women, 85% white). The average delta heart rate was 26 beats/min. Participants in the lowest tertile of delta heart rate (<20 beats/min) had higher risk-adjusted mortality (hazard ratio [HR] 1.18; 95% confidence interval [CI][1.00, 1.40]) and incident CHD (HR 1.37; 95% CI[1.05, 1.78]) compared to subjects in the highest tertile (≥30 beats/min), with a significant linear trend across tertiles (P for trend <0.05 for both outcomes). This relationship was not significant after adjustment for distance walked. CONCLUSION Impaired chronotropic response during six-minute walk test was associated with an increased risk of mortality and incident CHD among the elderly. This association was attenuated after adjusting for distance walked. PMID:22722364
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Electrodes as social glue: measuring heart rate promotes giving in the trust game.
Van Lange, Paul A M; Finkenauer, Catrin; Popma, Arne; van Vugt, Mark
2011-06-01
While physiological measures are increasingly used to help us understand the workings of interpersonal trust (and related behaviors), we know very little about the effects of such measures on trust. We examined the effects of a classic measure, the measurement of heart rate using a standard protocol, on behavioral trust in dyads of women who did not know each other. Behavioral trust was assessed in the trust game, in which the trustor decides how much money from their subject payment to give to a trustee, while knowing that the experimenter triples that amount before giving it to the trustee, after which the trustee decides how much money to return to the trustor. As predicted, we found greater levels of behavioral trust in the trust game, as well as greater returns by the trustees (which were accounted for by trustor's giving), in the heart rate (HR) than in no heart rate (NHR) measurement condition. Parallel findings were observed for self-reported trust. Findings are discussed in terms of the idea that the elusive effects of a protocol for measuring heart rate can cause pronounced effects on subsequent social interactions via enhanced interpersonal trust. 2011 Elsevier B.V. All rights reserved.
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Effect of muscle mass and intensity of isometric contraction on heart rate.
Gálvez, J M; Alonso, J P; Sangrador, L A; Navarro, G
2000-02-01
The purpose of this study was to determine the effect of muscle mass and the level of force on the contraction-induced rise in heart rate. We conducted an experimental study in a sample of 28 healthy men between 20 and 30 yr of age (power: 95%, alpha: 5%). Smokers, obese subjects, and those who performed regular physical activity over a certain amount of energetic expenditure were excluded from the study. The participants exerted two types of isometric contractions: handgrip and turning a 40-cm-diameter wheel. Both were sustained to exhaustion at 20 and 50% of maximal force. Twenty-five subjects finished the experiment. Heart rate increased a mean of 15.1 beats/min [95% confidence interval (CI): 5.5-24.6] from 20 to 50% handgrip contractions, and 20.7 beats/min (95% CI: 11.9-29.5) from 20 to 50% wheel-turn contractions. Heart rate also increased a mean of 13.3 beats/min (95% CI: 10.4-16.1) from handgrip to wheel-turn contractions at 20% maximal force, and 18.9 beats/min (95% CI: 9. 8-28.0) from handgrip to wheel-turn contractions at 50% maximal force. We conclude that the magnitude of the heart rate increase during isometric exercise is related to the intensity of the contraction and the mass of the contracted muscle.
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A dual-input nonlinear system analysis of autonomic modulation of heart rate
NASA Technical Reports Server (NTRS)
Chon, K. H.; Mullen, T. J.; Cohen, R. J.
1996-01-01
Linear analyses of fluctuations in heart rate and other hemodynamic variables have been used to elucidate cardiovascular regulatory mechanisms. The role of nonlinear contributions to fluctuations in hemodynamic variables has not been fully explored. This paper presents a nonlinear system analysis of the effect of fluctuations in instantaneous lung volume (ILV) and arterial blood pressure (ABP) on heart rate (HR) fluctuations. To successfully employ a nonlinear analysis based on the Laguerre expansion technique (LET), we introduce an efficient procedure for broadening the spectral content of the ILV and ABP inputs to the model by adding white noise. Results from computer simulations demonstrate the effectiveness of broadening the spectral band of input signals to obtain consistent and stable kernel estimates with the use of the LET. Without broadening the band of the ILV and ABP inputs, the LET did not provide stable kernel estimates. Moreover, we extend the LET to the case of multiple inputs in order to accommodate the analysis of the combined effect of ILV and ABP effect on heart rate. Analyzes of data based on the second-order Volterra-Wiener model reveal an important contribution of the second-order kernels to the description of the effect of lung volume and arterial blood pressure on heart rate. Furthermore, physiological effects of the autonomic blocking agents propranolol and atropine on changes in the first- and second-order kernels are also discussed.
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Heart Rate Responses to Autonomic Challenges in Obstructive Sleep Apnea
Macey, Paul M.; Kumar, Rajesh; Woo, Mary A.; Yan-Go, Frisca L.; Harper, Ronald M.
2013-01-01
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 females. The
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Bohnhorst, B; Seidel, K; Böhne, C; Peter, C; Pirr, S
2018-06-21
This study compiled percentiles for cardiorespiratory parameters in healthy term neonates during quiet sleep. We enrolled 215 healthy term neonates born at Hannover Medical School, Germany, between October 2011 and March 2013. They were prospectively observed on the maternity ward at a median age of two days using six-hour recordings of pulse oximeter plethysmography, oxygen saturation, thoracic breathing movements and electrocardiogram during sleep in a supine position. We examined their heart rate, respiratory rate and oxygen saturation during quiet sleep, plus bradycardias, apnoeas lasting at least four seconds and desaturations below 85%. The third, 50 th and 97 th percentiles were calculated as follows: heart rate 87, 112 and 133 beats per minute, respiratory rate 32, 44 and 57 per minute and oxygen saturation 94, 98 and 100%. Desaturations, apnoeas and bradycardias below 80 beats per minute were common and recorded in 54%, 98% and 30% of participants. In contrast, only 7% experienced bradycardias of less than two-thirds of the baseline heart rate and 5% experienced apnoeas exceeding 15 seconds. Our results will facilitate the evidence-based valuation of cardiorespiratory parameters in term neonates and help to validate the significance of cardiorespiratory events in preterm infants at discharge. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
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An adaptive Kalman filter technique for context-aware heart rate monitoring.
Xu, Min; Goldfain, Albert; Dellostritto, Jim; Iyengar, Satish
2012-01-01
Traditional physiological monitoring systems convert a person's vital sign waveforms, such as heart rate, respiration rate and blood pressure, into meaningful information by comparing the instant reading with a preset threshold or a baseline without considering the contextual information of the person. It would be beneficial to incorporate the contextual data such as activity status of the person to the physiological data in order to obtain a more accurate representation of a person's physiological status. In this paper, we proposed an algorithm based on adaptive Kalman filter that describes the heart rate response with respect to different activity levels. It is towards our final goal of intelligent detection of any abnormality in the person's vital signs. Experimental results are provided to demonstrate the feasibility of the algorithm.
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Using Heart Rate Monitors in Research on Fitness Levels of Children in Physical Education.
ERIC Educational Resources Information Center
Strand, Brad; Reeder, Steve
1993-01-01
Demonstrates the use of heart rate monitors (HRMs) in fitness research and examines heart rate intensity levels of middle school students while they participated in a variety of physical education activities throughout a school year. Research shows the HRM has considerable potential in assessing fitness achievements in school-age children. (GLR)
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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.
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THE EFFECTS OF SPINAL ANESTHESIA ON THE FETAL HEART RATE
Downs, Howard S.; Morrison, Philip H.
1963-01-01
The effect of spinal anesthesia on fetal heart rate is due to maternal hypotension and subsequent fetal hypoxia. Maternal hypotension of 80 mm of mercury for five minutes almost always results in hypoxic fetal bradycardia. This bradycardia is gradual in onset, and may be preceded by a short period of fetal tachycardia. There is a lag in the return of fetal heart rate to normal after maternal blood pressure has normalized. Similar bradycardia has been observed in maternal syncope unassociated with anesthesia. Maternal hypotension should be prevented, and if it occurs should be corrected early. Administration of a vasopressor drug is the treatment of choice, with oxygen and fluids as indicated. ImagesFigure 1.Figure 3.Figure 4.Figure 5. PMID:14084683
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A real-time approach for heart rate monitoring using a Hilbert transform in seismocardiograms.
Jafari Tadi, Mojtaba; Lehtonen, Eero; Hurnanen, Tero; Koskinen, Juho; Eriksson, Jonas; Pänkäälä, Mikko; Teräs, Mika; Koivisto, Tero
2016-11-01
Heart rate monitoring helps in assessing the functionality and condition of the cardiovascular system. We present a new real-time applicable approach for estimating beat-to-beat time intervals and heart rate in seismocardiograms acquired from a tri-axial microelectromechanical accelerometer. Seismocardiography (SCG) is a non-invasive method for heart monitoring which measures the mechanical activity of the heart. Measuring true beat-to-beat time intervals from SCG could be used for monitoring of the heart rhythm, for heart rate variability analysis and for many other clinical applications. In this paper we present the Hilbert adaptive beat identification technique for the detection of heartbeat timings and inter-beat time intervals in SCG from healthy volunteers in three different positions, i.e. supine, left and right recumbent. Our method is electrocardiogram (ECG) independent, as it does not require any ECG fiducial points to estimate the beat-to-beat intervals. The performance of the algorithm was tested against standard ECG measurements. The average true positive rate, positive prediction value and detection error rate for the different positions were, respectively, supine (95.8%, 96.0% and ≃0.6%), left (99.3%, 98.8% and ≃0.001%) and right (99.53%, 99.3% and ≃0.01%). High correlation and agreement was observed between SCG and ECG inter-beat intervals (r > 0.99) for all positions, which highlights the capability of the algorithm for SCG heart monitoring from different positions. Additionally, we demonstrate the applicability of the proposed method in smartphone based SCG. In conclusion, the proposed algorithm can be used for real-time continuous unobtrusive cardiac monitoring, smartphone cardiography, and in wearable devices aimed at health and well-being applications.
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Accuracy of pulse oximetry in assessing heart rate of infants in the neonatal intensive care unit.
Singh, Jasbir K S B; Kamlin, C Omar F; Morley, Colin J; O'Donnell, Colm P F; Donath, Susan M; Davis, Peter G
2008-05-01
To determine the accuracy of pulse oximetry measurement of heart rate in the neonatal intensive care unit. Stable preterm infants were monitored with a pulse oximeter and an ECG. The displays of both monitors were captured on video. Heart rate data from both monitors, including measures of signal quality, were extracted and analysed using Bland Altman plots. In 30 infants the mean (SD) difference between heart rate measured by pulse oximetry and electrocardiography was -0.4 (12) beats per minute. Accuracy was maintained when the signal quality or perfusion was low. Pulse oximetry may provide a useful measurement of heart rate in the neonatal intensive care unit. Studies of this technique in the delivery room are indicated.
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Ekström, Andreas; Hellgren, Kim; Gräns, Albin; Pichaud, Nicolas; Sandblom, Erik
2016-04-15
Time course studies are critical for understanding regulatory mechanisms and temporal constraints in ectothermic animals acclimating to warmer temperatures. Therefore, we investigated the dynamics of heart rate and its neuro-humoral control in rainbow trout ( ITALIC! Onchorhynchus mykissL.) acclimating to 16°C for 39 days after being acutely warmed from 9°C. Resting heart rate was 39 beats min(-1)at 9°C, and increased significantly when fish were acutely warmed to 16°C ( ITALIC! Q10=1.9), but then declined during acclimation ( ITALIC! Q10=1.2 at day 39), mainly due to increased cholinergic inhibition while the intrinsic heart rate and adrenergic tone were little affected. Maximum heart rate also increased with warming, although a partial modest decrease occurred during the acclimation period. Consequently, heart rate scope exhibited a complex pattern with an initial increase with acute warming, followed by a steep decline and then a subsequent increase, which was primarily explained by cholinergic inhibition of resting heart rate. © 2016. Published by The Company of Biologists Ltd.
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Chen, Han-Yang; Chauhan, Suneet P; Ananth, Cande V; Vintzileos, Anthony M; Abuhamad, Alfred Z
2011-06-01
To examine the association between electronic fetal heart rate monitoring and neonatal and infant mortality, as well as neonatal morbidity. We used the United States 2004 linked birth and infant death data. Multivariable log-binomial regression models were fitted to estimate risk ratio for association between electronic fetal heart rate monitoring and mortality, while adjusting for potential confounders. In 2004, 89% of singleton pregnancies had electronic fetal heart rate monitoring. Electronic fetal heart rate monitoring was associated with significantly lower infant mortality (adjusted relative risk, 0.75); this was mainly driven by the lower risk of early neonatal mortality (adjusted relative risk, 0.50). In low-risk pregnancies, electronic fetal heart rate monitoring was associated with decreased risk for Apgar scores <4 at 5 minutes (relative risk, 0.54); in high-risk pregnancies, with decreased risk of neonatal seizures (relative risk, 0.65). In the United States, the use of electronic fetal heart rate monitoring was associated with a substantial decrease in early neonatal mortality and morbidity that lowered infant mortality. Copyright © 2011 Mosby, Inc. All rights reserved.
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Steinberg, Benjamin A; Kim, Sunghee; Thomas, Laine; Fonarow, Gregg C; Gersh, Bernard J; Holmqvist, Fredrik; Hylek, Elaine; Kowey, Peter R; Mahaffey, Kenneth W; Naccarelli, Gerald; Reiffel, James A; Chang, Paul; Peterson, Eric D; Piccini, Jonathan P
2015-01-01
Background Most patients with atrial fibrillation (AF) require rate control; however, the optimal target heart rate remains under debate. We aimed to assess rate control and subsequent outcomes among patients with permanent AF. Methods and Results We studied 2812 US outpatients with permanent AF in the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation. Resting heart rate was measured longitudinally and used as a time-dependent covariate in multivariable Cox models of all-cause and cause-specific mortality during a median follow-up of 24 months. At baseline, 7.4% (n=207) had resting heart rate <60 beats per minute (bpm), 62% (n=1755) 60 to 79 bpm, 29% (n=817) 80 to 109 bpm, and 1.2% (n=33) ≥110 bpm. Groups did not differ by age, previous cerebrovascular disease, heart failure status, CHA2DS2-VASc scores, renal function, or left ventricular function. There were significant differences in race (P=0.001), sinus node dysfunction (P=0.004), and treatment with calcium-channel blockers (P=0.006) and anticoagulation (P=0.009). In analyses of continuous heart rates, lower heart rate ≤65 bpm was associated with higher all-cause mortality (adjusted hazard ratio [HR], 1.15 per 5-bpm decrease; 95% CI, 1.01 to 1.32; P=0.04). Similarly, increasing heart rate >65 bpm was associated with higher all-cause mortality (adjusted HR, 1.10 per 5-bpm increase; 95% CI, 1.05 to 1.15; P<0.0001). This relationship was consistent across endpoints and in a broader sensitivity analysis of permanent and nonpermanent AF patients. Conclusions Among patients with permanent AF, there is a J-shaped relationship between heart rate and mortality. These data support current guideline recommendations, and clinical trials are warranted to determine optimal rate control. Clinical Trial Registration URL: http://clinicaltrials.gov/. Unique identifier: NCT01165710. PMID:26370445
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Shaffer, Fred
2015-01-01
Heart rate variability, the change in the time intervals between adjacent heartbeats, is an emergent property of interdependent regulatory systems that operates on different time scales to adapt to environmental and psychological challenges. This article briefly reviews neural regulation of the heart and offers some new perspectives on mechanisms underlying the very low frequency rhythm of heart rate variability. Interpretation of heart rate variability rhythms in the context of health risk and physiological and psychological self-regulatory capacity assessment is discussed. The cardiovascular regulatory centers in the spinal cord and medulla integrate inputs from higher brain centers with afferent cardiovascular system inputs to adjust heart rate and blood pressure via sympathetic and parasympathetic efferent pathways. We also discuss the intrinsic cardiac nervous system and the heart-brain connection pathways, through which afferent information can influence activity in the subcortical, frontocortical, and motor cortex areas. In addition, the use of real-time HRV feedback to increase self-regulatory capacity is reviewed. We conclude that the heart's rhythms are characterized by both complexity and stability over longer time scales that reflect both physiological and psychological functional status of these internal self-regulatory systems. PMID:25694852
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McCraty, Rollin; Shaffer, Fred
2015-01-01
Heart rate variability, the change in the time intervals between adjacent heartbeats, is an emergent property of interdependent regulatory systems that operates on different time scales to adapt to environmental and psychological challenges. This article briefly reviews neural regulation of the heart and offers some new perspectives on mechanisms underlying the very low frequency rhythm of heart rate variability. Interpretation of heart rate variability rhythms in the context of health risk and physiological and psychological self-regulatory capacity assessment is discussed. The cardiovascular regulatory centers in the spinal cord and medulla integrate inputs from higher brain centers with afferent cardiovascular system inputs to adjust heart rate and blood pressure via sympathetic and parasympathetic efferent pathways. We also discuss the intrinsic cardiac nervous system and the heart-brain connection pathways, through which afferent information can influence activity in the subcortical, frontocortical, and motor cortex areas. In addition, the use of real-time HRV feedback to increase self-regulatory capacity is reviewed. We conclude that the heart's rhythms are characterized by both complexity and stability over longer time scales that reflect both physiological and psychological functional status of these internal self-regulatory systems.
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Azevedo, Luciene Ferreira; Perlingeiro, Patricia; Hachul, Denise Tessariol; Gomes-Santos, Igor Lucas; Tsutsui, Jeane Mike; Negrao, Carlos Eduardo; De Matos, Luciana D N J
2016-01-01
Different season trainings may influence autonomic and non-autonomic cardiac control of heart rate and provokes specific adaptations on heart's structure in athletes. We investigated the influence of transition training (TT) and competitive training (CT) on resting heart rate, its mechanisms of control, spontaneous baroreflex sensitivity (BRS) and relationships between heart rate mechanisms and cardiac structure in professional cyclists (N = 10). Heart rate (ECG) and arterial blood pressure (Pulse Tonometry) were recorded continuously. Autonomic blockade was performed (atropine-0.04 mg.kg-1; esmolol-500 μg.kg-1 = 0.5 mg). Vagal effect, intrinsic heart rate, parasympathetic (n) and sympathetic (m) modulations, autonomic influence, autonomic balance and BRS were calculated. Plasma norepinephrine (high-pressure liquid chromatography) and cardiac structure (echocardiography) were evaluated. Resting heart rate was similar in TT and CT. However, vagal effect, intrinsic heart rate, autonomic influence and parasympathetic modulation (higher n value) decreased in CT (P≤0.05). Sympathetic modulation was similar in both trainings. The autonomic balance increased in CT but still showed parasympathetic predominance. Cardiac diameter, septum and posterior wall thickness and left ventricular mass also increased in CT (P<0.05) as well as diastolic function. We observed an inverse correlation between left ventricular diastolic diameter, septum and posterior wall thickness and left ventricular mass with intrinsic heart rate. Blood pressure and BRS were similar in both trainings. Intrinsic heart rate mechanism is predominant over vagal effect during CT, despite similar resting heart rate. Preserved blood pressure levels and BRS during CT are probably due to similar sympathetic modulation in both trainings.
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Endothelin-1 signalling controls early embryonic heart rate in vitro and in vivo.
Karppinen, S; Rapila, R; Mäkikallio, K; Hänninen, S L; Rysä, J; Vuolteenaho, O; Tavi, P
2014-02-01
Spontaneous activity of embryonic cardiomyocytes originates from sarcoplasmic reticulum (SR) Ca(2+) release during early cardiogenesis. However, the regulation of heart rate during embryonic development is still not clear. The aim of this study was to determine how endothelin-1 (ET-1) affects the heart rate of embryonic mice, as well as the pathway through which it exerts its effects. The effects of ET-1 and ET-1 receptor inhibition on cardiac contraction were studied using confocal Ca(2+) imaging of isolated mouse embryonic ventricular cardiomyocytes and ultrasonographic examination of embryonic cardiac contractions in utero. In addition, the amount of ET-1 peptide and ET receptor a (ETa) and b (ETb) mRNA levels were measured during different stages of development of the cardiac muscle. High ET-1 concentration and expression of both ETa and ETb receptors was observed in early cardiac tissue. ET-1 was found to increase the frequency of spontaneous Ca(2+) oscillations in E10.5 embryonic cardiomyocytes in vitro. Non-specific inhibition of ET receptors with tezosentan caused arrhythmia and bradycardia in isolated embryonic cardiomyocytes and in whole embryonic hearts both in vitro (E10.5) and in utero (E12.5). ET-1-mediated stimulation of early heart rate was found to occur via ETb receptors and subsequent inositol trisphosphate receptor activation and increased SR Ca(2+) leak. Endothelin-1 is required to maintain a sufficient heart rate, as well as to prevent arrhythmia during early development of the mouse heart. This is achieved through ETb receptor, which stimulates Ca(2+) leak through IP3 receptors. © 2013 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.
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Metabolic support for the heart: complementary therapy for heart failure?
Heggermont, Ward A; Papageorgiou, Anna-Pia; Heymans, Stephane; van Bilsen, Marc
2016-12-01
The failing heart has an increased metabolic demand and at the same time suffers from impaired energy efficiency, which is a detrimental combination. Therefore, therapies targeting the energy-deprived failing heart and rewiring cardiac metabolism are of great potential, but are lacking in daily clinical practice. Metabolic impairment in heart failure patients has been well characterized for patients with reduced ejection fraction, and is coming of age in patients with 'preserved' ejection fraction. Targeting cardiomyocyte metabolism in heart failure could complement current heart failure treatments that do improve cardiovascular haemodynamics, but not the energetic status of the heart. In this review, we discuss the hallmarks of normal cardiac metabolism, typical metabolic disturbances in heart failure, and past and present therapeutic targets that impact on cardiac metabolism. © 2016 The Authors. European Journal of Heart Failure © 2016 European Society of Cardiology.
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Lenoir, Augustin; Trachsel, Dagmar S; Younes, Mohamed; Barrey, Eric; Robert, Céline
2017-01-01
Analysis of the heart rate variability (HRV) gains more and more importance in the assessment of training practice and welfare in equine industry. It relies on mathematical analyses of reliably and accurately measured variations in successive inter-beat intervals, measured as RR intervals. Nowadays, the RR intervals can be obtained through two different techniques: a heart rate meter (HRM) or an electrocardiogram (ECG). The agreement and reliability of these devices has not been fully assessed, especially for recordings during exercise. The purpose of this study was to assess the agreement of two commercially available devices using the two mentioned techniques (HRM vs ECG) for HRV analysis during a standardized exercise test. Simultaneous recordings obtained during light exercise and during canter with both devices were available for 36 horses. Data were compared using a Bland-Altman analysis and the Lin's coefficient. The agreement between the assessed HRV measures from the data obtained from the ECG and HRM was acceptable only for the mean RR interval and the mean heart rate. For the other studied measures (SDNN, root mean square of successive differences, SD1, SD2, low frequency, high frequency), the agreement between the devices was too poor for them to be considered as interchangeable in these recording conditions. The agreement tended also to be worse when speed of the exercise increased. Therefore, it is necessary to be careful when interpreting and comparing results of HRV analysis during exercise, as the results will depend upon recording devices. Furthermore, corrections and data processing included in the software of the devices affect largely the output used in the subsequent HRV analysis; this must be considered in the choice of the device.
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Lerma, Claudia; Wessel, Niels; Schirdewan, Alexander; Kurths, Jürgen; Glass, Leon
2008-07-01
The objective was to determine the characteristics of heart rate variability and ventricular arrhythmias prior to the onset of ventricular tachycardia (VT) in patients with an implantable cardioverter defibrillator (ICD). Sixty-eight beat-to-beat time series from 13 patients with an ICD were analyzed to quantify heart rate variability and ventricular arrhythmias. The episodes of VT were classified in one of two groups depending on whether the sinus rate in the 1 min preceding the VT was greater or less than 90 beats per minute. In a subset of patients, increased heart rate and reduced heart rate variability was often observed up to 20 min prior to the VT. There was a non-significant trend to higher incidence of premature ventricular complexes (PVCs) before VT compared to control recordings. The patterns of the ventricular arrhythmias were highly heterogeneous among different patients and even within the same patient. Analysis of the changes of heart rate and heart rate variability may have predictive value about the onset of VT in selected patients. The patterns of ventricular arrhythmia could not be used to predict onset of VT in this group of patients.
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Heart rate variability alters cardiac repolarization and electromechanical dynamics.
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.
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Validity of a heart rate monitor during work in the laboratory and on the Space Shuttle
NASA Technical Reports Server (NTRS)
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.
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Marso, Steven P; Hardy, Elise; Han, Jenny; Wang, Hui; Chilton, Robert J
2018-04-01
Glucagon-like peptide-1 receptor agonists (GLP-1RAs) improve glycemia in patients with type 2 diabetes, but heart rate increases have been observed. A pooled post hoc analysis of 11 randomized clinical trials (N = 4595) of 10-30 weeks' duration from the exenatide once-weekly (QW) development program evaluated heart rate with exenatide QW (intervention group) and exenatide twice daily (BID), liraglutide, and non-GLP-1RAs (insulin, metformin, pioglitazone, and sitagliptin) (comparison groups). The time course and size of heart rate changes from baseline and the relationship of heart rate change with baseline heart rate were studied. A multivariate analysis (9 studies; N = 3903) examined associations between patient characteristics or treatments and heart rate increases. Mean baseline heart rate ± standard deviation was 75.0 ± 8.5 beats per minute (bpm) with exenatide QW (n = 2096), 75.8 ± 8.7 bpm with exenatide BID (n = 606), 75.2 ± 8.9 bpm with liraglutide (n = 450), and 74.5 ± 8.6 bpm with non-GLP-1RAs (n = 1443). Least-squares mean ± standard error changes from baseline to final heart rate were + 2.7 ± 0.2, + 1.0 ± 0.3, and + 3.0 ± 0.4 bpm with exenatide QW, exenatide BID, and liraglutide, respectively, and - 0.8 ± 0.2 bpm with non-GLP-1RAs. The size and direction of heart rate changes in individual patients varied within each treatment group at all time points. At posttreatment follow-up, heart rate reverted to the baseline level after GLP-1RA discontinuation. Heart rate changes correlated negatively with baseline heart rate for all therapies (r = - 0.3 to - 0.4). Baseline heart rate was the strongest predictor of increased heart rate. Small increases in heart rate were associated with exenatide QW, exenatide BID, and liraglutide treatments but reverted to baseline after discontinuation. Increases were more likely in patients with a low baseline heart rate. The clinical relevance of these heart rate increases is
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Valle, Roberto; Aspromonte, Nadia; Carbonieri, Emanuele; D'Eri, Alessandra; Feola, Mauro; Giovinazzo, Prospero; Noventa, Federica; Prevaldi, Carolina; Barro, Sabrina; Milani, Loredano
2008-06-06
B-type natriuretic peptide is the most powerful predictor of long term prognosis in patients hospitalised with heart failure. On an outsetting basis, a decrease in B-type natriuretic peptide levels is associated to a decrease in event rate for outpatients managed using the neuro-hormone levels as the target in heart failure therapy. We have retrospectively checked whether the addition of pre-discharge B-type natriuretic peptide levels to a clinical-instrumental decisional score for discharge decision in patients admitted for heart failure reduced readmission rate for heart failure and related cost. We studied two series of consecutive patients admitted to the Heart Failure Unit due to acute heart failure as a main diagnosis. One-hundred and forty-nine patients discharged on the basis of the sole clinical acumen were compared to one hundred and sixty-six subjects discharged adding B-type natriuretic peptide levels to the decisional score. During a six-month follow-up period, there were 52 readmissions (35%) among the clinical group (n=149) compared with 38 (23%) readmissions in the B-type natriuretic peptide group (n=166) (chi(2)=5.5; P=0.02). Survival did not differ between groups (87%). Changes in B-type natriuretic peptide values were correlated to clinical events: a B-type natriuretic peptide value on discharge of < or =250 pg/ml or a reduction of > or =30% in B-type natriuretic peptide values predicted a 23% event rate (death, plus readmission for heart failure), whereas a far higher percentage (71%) were observed in the remaining patients (chi(2)=32.7; P=0.001). Likewise, the overall costs of care were lower (-7%) in the B-type natriuretic peptide group: 2.781+/-923 vs 2.978+/-1.057 euros per patient respectively. our study suggest that the addition of pre-discharge B-type natriuretic peptide levels to a clinical-instrumental decisional score for discharge decision in patients admitted for heart failure may contribute to reduce the number of readmissions and
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Boudet, Gil; Walther, Guillaume; Courteix, Daniel; Obert, Philippe; Lesourd, Bruno; Pereira, Bruno; Chapier, Robert; Vinet, Agnès; Chamoux, Alain; Naughton, Geraldine; Poirier, Paul; Dutheil, Frédéric
2017-02-01
Aims To analyse the effects of different modalities of exercise training on heart rate variability (HRV) in individuals with metabolic syndrome (MetS). Methods and results Eighty MetS participants (aged 50-70 years) were housed and managed in an inpatient medical centre for 21 days, including weekends. Physical activity and food intake/diet were intensively monitored. Participants were randomly assigned into three training groups, differing only by intensity of exercise: moderate-endurance-moderate-resistance ( re), high-resistance-moderate-endurance ( Re), and moderate-resistance-high-endurance ( rE). HRV was recorded before and after the intervention by 24-hour Holter electrocardiogram. Although mean 24-hour heart rate decreased more in Re than re (-11.6 ± 1.6 vs. -4.8 ± 2.1%; P = 0.010), low frequency/high frequency decreased more in re than Re (-20.4 ± 5.5% vs. + 20.4 ± 9.1%; P = 0.002) and rE (-20.4 ± 5.5% vs. -0.3 ± 11.1%; P = 0.003). Very low frequency increased more in Re than re (+121.2 ± 35.7 vs. 42.9 ± 11.3%; P = 0.004). For all HRV parameters, rE ranged between re and Re values. Low frequency/high frequency changes were linked with visceral fat loss only in re (coefficient 5.9, 95% CI 1.9-10.0; P = 0.004). By day 21, HRV parameters of MetS groups (heart rate -8.6 ± 1.0%, standard deviation of R-R intervals + 34.0 ± 6.6%, total power + 63.3 ± 11.1%; P < 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
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Modeling heart rate variability including the effect of sleep stages
NASA Astrophysics Data System (ADS)
Soliński, Mateusz; Gierałtowski, Jan; Żebrowski, Jan
2016-02-01
We propose a model for heart rate variability (HRV) of a healthy individual during sleep with the assumption that the heart rate variability is predominantly a random process. Autonomic nervous system activity has different properties during different sleep stages, and this affects many physiological systems including the cardiovascular system. Different properties of HRV can be observed during each particular sleep stage. We believe that taking into account the sleep architecture is crucial for modeling the human nighttime HRV. The stochastic model of HRV introduced by Kantelhardt et al. was used as the initial starting point. We studied the statistical properties of sleep in healthy adults, analyzing 30 polysomnographic recordings, which provided realistic information about sleep architecture. Next, we generated synthetic hypnograms and included them in the modeling of nighttime RR interval series. The results of standard HRV linear analysis and of nonlinear analysis (Shannon entropy, Poincaré plots, and multiscale multifractal analysis) show that—in comparison with real data—the HRV signals obtained from our model have very similar properties, in particular including the multifractal characteristics at different time scales. The model described in this paper is discussed in the context of normal sleep. However, its construction is such that it should allow to model heart rate variability in sleep disorders. This possibility is briefly discussed.
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Modeling heart rate variability by stochastic feedback
NASA Technical Reports Server (NTRS)
Amaral, L. A.; Goldberger, A. L.; Stanley, H. E.
1999-01-01
We consider the question of how the cardiac rhythm spontaneously self-regulates and propose a new mechanism as a possible answer. We model the neuroautonomic regulation of the heart rate as a stochastic feedback system and find that the model successfully accounts for key characteristics of cardiac variability, including the 1/f power spectrum, the functional form and scaling of the distribution of variations of the interbeat intervals, and the correlations in the Fourier phases which indicate nonlinear dynamics.
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The Relation of Arm Exercise Peak Heart Rate to Stress Test Results and Outcome.
Xian, Hong; Liu, Weijian; Marshall, Cynthia; Chandiramani, Pooja; Bainter, Emily; Martin, Wade H
2016-09-01
Arm exercise is an alternative to pharmacologic stress testing for >50% of patients unable to perform treadmill exercise, but no data exist regarding the effect of attained peak arm exercise heart rate on test sensitivity. Thus, the purpose of this investigation was to characterize the relationship of peak arm exercise heart rate responses to abnormal stress test findings, coronary revascularization, and mortality in patients unable to perform leg exercise. From 1997 until 2002, arm cycle ergometer stress tests were performed in 443 consecutive veterans age 64.1 yr (11.0 yr) (mean (SD)), of whom 253 also underwent myocardial perfusion imaging (MPI). Patients were categorized by frequency distributions of quartiles of percentage age-predicted peak heart rate (APPHR), heart rate reserve (HRR), and peak heart rate-systolic blood pressure product (PRPP). Exercise-induced ST-segment depression, abnormal MPI findings, coronary revascularization, and 12.0-yr (1.3 yr) Kaplan-Meier all-cause and cardiovascular mortality plots were then characterized by quartiles of APPHR, HRR, and PRPP. A reduced frequency of abnormal arm exercise ECG results was associated only with the lowest quartile of APPHR (≤69%) and HRR (≤43%), whereas higher frequency of abnormal MPI findings exhibited an inverse relationship trend with lower APPHR (P = 0.10) and HRR (P = 0.12). There was a strong inverse association of APPHR, HRR, and PRPP with all-cause (all P ≤ 0.01) and cardiovascular (P < 0.05) mortality. The frequency of coronary revascularization was unrelated to APPHR or HRR. Arm exercise ECG stress test sensitivity is only reduced at ≤69% APPHR or ≤43% HRR, whereas arm exercise MPI sensitivity and referral for coronary revascularization after arm exercise stress testing are not adversely affected by even a severely blunted peak heart rate. However, both all-cause mortality and cardiovascular mortality are strongly and inversely related to APPHR and HRR.
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Metabolic enzymes dysregulation in heart failure: the prospective therapy.
Parihar, Priyanka; Parihar, Mordhwaj Singh
2017-01-01
The heart failure accounts for the highest mortality rate all over the world. The development of preventive therapeutic approaches is still in their infancy. Owing to the extremely high energy demand of the heart, the bioenergetics pathways need to respond efficiently based on substrate availability. The metabolic regulation of such heart bioenergetics is mediated by various rate limiting enzymes involved in energy metabolism. Although all the pertinent mechanisms are not clearly understood, the progressive decline in the activity of metabolic enzymes leading to diminished ATP production is known to cause progression of the heart failure. Therefore, metabolic therapy that can maintain the appropriate activities of metabolic enzymes can be a promising approach for the prevention and treatment of the heart failure. The flavonoids that constitute various human dietary ingredients also effectively offer a variety of health benefits. The flavonoids target a variety of metabolic enzymes and facilitate effective management of the equilibrium between production and utilization of energy in the heart. This review discusses the broad impact of metabolic enzymes in the heart functions and explains how the dysregulated enzyme activity causes the heart failure. In addition, the prospects of targeting dysregulated metabolic enzymes by developing flavonoid-based metabolic approaches are discussed.
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Villelabeitia-Jaureguizar, Koldobika; Vicente-Campos, Davinia; Senen, Alejandro Berenguel; Jiménez, Verónica Hernández; Garrido-Lestache, María Elvira Barrios; Chicharro, Jose López
2017-10-01
Heart rate recovery (HRR) has been considered a prognostic and mortality indicator in both healthy and coronary patients. Physical exercise prescription has shown improvements in VO 2 peak and HRR, but most of the studies have been carried out applying continuous training at a moderate intensity, being very limited the use of protocols of high intensity interval training in coronary patients. We aimed to compare the effects of a moderate continuous training (MCT) versus a high intensity interval training (HIIT) programme on VO 2 peak and HRR. Seventy three coronary patients were assigned to either HIIT or MCT groups for 8weeks. Incremental exercise tests in a cycloergometer were performed to obtain VO 2 peak data and heart rate was monitored during and after the exercise test to obtain heart rate recovery data. Both exercise programmes significantly increase VO 2 peak with a higher increase in the HIIT group (HIIT: 4.5±4.46ml/kg/min vs MCT: 2.46±3.57ml/kg/min; p=0.039). High intensity interval training resulted in a significantly increase in HRR at the first and second minute of the recovery phase (15,44±7,04 vs 21,22±6,62, p<0,0001 and 23,73±9,64 vs 31,52±8,02, p<0,0001, respectively). The results of our research show that the application of HIIT to patients with chronic ischemic heart disease of low risk resulted in an improvement in VO 2 peak, and also improvements in post-exercise heart-rate recovery, compared with continuous training. Copyright © 2017 Elsevier B.V. All rights reserved.
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Decreased baseline variability on fetal heart rate pattern in a fetus with heterotaxy syndrome.
Yamada, Ryutaro; Takei, Kohta; Kaneshi, Yosuke; Morikawa, Mamoru; Cho, Kazutoshi; Minakami, Hisanori
2015-12-01
In a fetus with suspected heterotaxy syndrome, a decreased/absent baseline variability of fetal heart rate pattern developed at gestational week 36(+5) and continued for 5 days until birth at gestational week 37(+2), while repeat biophysical profile scorings with ultrasound were consistently unremarkable. This neonate weighing 2404 g with Apgar scores of 7 (1-min) and 8 (5-min) and umbilical arterial cord blood pH of 7.28 with base deficit of 3.9 mmol/L, showed a heart rate of 120 b.p.m. for 3 h after birth, but subsequently developed sinus bradycardia (84 b.p.m.) unresponsive to crying. Isoproterenol initiated 9 h after birth was effective in the increase of heart rate to 120 b.p.m. in this neonate. Brain magnetic resonance imaging at 16 days of age was unremarkable. The decreased/absent baseline variability of fetal heart rate pattern was speculated to have been caused by sinus node dysfunction, and not by reduced fetal oxygenation in this case. © 2015 Japan Society of Obstetrics and Gynecology.
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Diminished heart rate complexity in adolescent girls: a sign of vulnerability to anxiety disorders?
Fiol-Veny, Aina; De la Torre-Luque, Alejandro; Balle, Maria; Bornas, Xavier
2018-07-01
Diminished heart rate variability has been found to be associated with high anxiety symptomatology. Since adolescence is the period of onset for many anxiety disorders, this study aimed to determine sex- and anxiety-related differences in heart rate variability and complexity in adolescents. We created four groups according to sex and anxiety symptomatology: high-anxiety girls (n = 24) and boys (n = 25), and low-anxiety girls (n = 22) and boys (n = 24) and recorded their cardiac function while they performed regular school activities. A series of two-way (sex and anxiety) MANOVAs were performed on time domain variability, frequency domain variability, and non-linear complexity. We obtained no multivariate interaction effects between sex and anxiety, but highly anxious participants had lower heart rate variability than the low-anxiety group. Regarding sex, girls showed lower heart rate variability and complexity than boys. The results suggest that adolescent girls have a less flexible cardiac system that could be a marker of the girls' vulnerability to developing anxiety disorders.
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Critchley, Hugo D; Rotshtein, Pia; Nagai, Yoko; O'Doherty, John; Mathias, Christopher J; Dolan, Raymond J
2005-02-01
The James-Lange theory of emotion proposes that automatically generated bodily reactions not only color subjective emotional experience of stimuli, but also necessitate a mechanism by which these bodily reactions are differentially generated to reflect stimulus quality. To examine this putative mechanism, we simultaneously measured brain activity and heart rate to identify regions where neural activity predicted the magnitude of heart rate responses to emotional facial expressions. Using a forewarned reaction time task, we showed that orienting heart rate acceleration to emotional face stimuli was modulated as a function of the emotion depicted. The magnitude of evoked heart rate increase, both across the stimulus set and within each emotion category, was predicted by level of activity within a matrix of interconnected brain regions, including amygdala, insula, anterior cingulate, and brainstem. We suggest that these regions provide a substrate for translating visual perception of emotional facial expression into differential cardiac responses and thereby represent an interface for selective generation of visceral reactions that contribute to the embodied component of emotional reaction.
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Heart Rate Response and Lactic Acid Concentration in Squash Players.
ERIC Educational Resources Information Center
Beaudin, Paula; And Others
1978-01-01
It was concluded that playing squash is an activity that results in heart rate responses of sufficient intensity to elicit aerobic training effects without producing high lactic acid concentration in the blood. (MM)
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Winbo, Annika; Fosdal, Inger; Lindh, Maria; Diamant, Ulla-Britt; Persson, Johan; Wettrell, Göran; Rydberg, Annika
2015-08-01
Early diagnosis and risk stratification is of clinical importance in the long QT syndrome (LQTS), however, little genotype-specific data are available regarding fetal LQTS. We investigate third trimester fetal heart rate, routinely recorded within public maternal health care, as a possible marker for LQT1 genotype and phenotype. This retrospective study includes 184 fetuses from 2 LQT1 founder populations segregating p.Y111C and p.R518X (74 noncarriers and 110 KCNQ1 mutation carriers, whereof 13 double mutation carriers). Pedigree-based measured genotype analysis revealed significant associations between fetal heart rate, genotype, and phenotype; mean third trimester prelabor fetal heart rates obtained from obstetric records (gestational week 29-41) were lower per added mutation (no mutation, 143±5 beats per minute; single mutation, 134±8 beats per minute; double mutations, 111±6 beats per minute; P<0.0001), and lower in symptomatic versus asymptomatic mutation carriers (122±10 versus 137±9 beats per minute; P<0.0001). Strong correlations between fetal heart rate and neonatal heart rate (r=0.700; P<0.001), and postnatal QTc (r=-0.762; P<0.001) were found. In a multivariable model, fetal genotype explained the majority of variance in fetal heart rate (-10 beats per minute per added mutation; P<1.0×10(-23)). Arrhythmia symptoms and intrauterine β-blocker exposure each predicted -7 beats per minute, P<0.0001. In this study including 184 fetuses from 2 LQT1 founder populations, third trimester fetal heart rate discriminated between fetal genotypes and correlated with severity of postnatal cardiac phenotype. This finding strengthens the role of fetal heart rate in the early detection and risk stratification of LQTS, particularly for fetuses with double mutations, at high risk of early life-threatening arrhythmias. © 2015 American Heart Association, Inc.
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Heart rate reveals torpor at high body temperatures in lowland tropical free-tailed bats.
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.
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Wavelet and receiver operating characteristic analysis of heart rate variability
NASA Astrophysics Data System (ADS)
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.
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Predicting Bradycardia in Preterm Infants Using Point Process Analysis of Heart Rate.
Gee, Alan H; Barbieri, Riccardo; Paydarfar, David; Indic, Premananda
2017-09-01
Episodes of bradycardia are common and recur sporadically in preterm infants, posing a threat to the developing brain and other vital organs. We hypothesize that bradycardias are a result of transient temporal destabilization of the cardiac autonomic control system and that fluctuations in the heart rate signal might contain information that precedes bradycardia. We investigate infant heart rate fluctuations with a novel application of point process theory. In ten preterm infants, we estimate instantaneous linear measures of the heart rate signal, use these measures to extract statistical features of bradycardia, and propose a simplistic framework for prediction of bradycardia. We present the performance of a prediction algorithm using instantaneous linear measures (mean area under the curve = 0.79 ± 0.018) for over 440 bradycardia events. The algorithm achieves an average forecast time of 116 s prior to bradycardia onset (FPR = 0.15). Our analysis reveals that increased variance in the heart rate signal is a precursor of severe bradycardia. This increase in variance is associated with an increase in power from low content dynamics in the LF band (0.04-0.2 Hz) and lower multiscale entropy values prior to bradycardia. Point process analysis of the heartbeat time series reveals instantaneous measures that can be used to predict infant bradycardia prior to onset. Our findings are relevant to risk stratification, predictive monitoring, and implementation of preventative strategies for reducing morbidity and mortality associated with bradycardia in neonatal intensive care units.
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Katheria, Anup; Rich, Wade; Finer, Neil
2012-11-01
To compare the time required to obtain a continuous audible heart rate signal from an electrocardiogram (ECG) monitor and pulse oximeter (PO) in infants requiring resuscitation. Infants who had both ECG and PO placed during resuscitation were analyzed using video and analog recordings. The median times from arrival until the ECG electrodes and PO sensor were placed, and the time to achieve audible tones from the devices, were compared. Forty-six infants had ECG and PO data. Thirty infants were very low birth weight (23-30 weeks). There was a difference in the median total time to place either device (26 vs 38 seconds; P = .04), and a difference (P < .001) in the time to achieve an audible heart rate signal after ECG lead (2 seconds) versus PO probe (24 seconds) placement. In infants weighing >1500 g (n = 16), the median time (interquartile range) to place the ECG was 20 seconds (14-43) whereas the time to place the PO was 36 seconds (28-56) (P = .74). The median times (interquartile range) to acquire a signal from the ECG and PO were 4 seconds (1-6) and 32 seconds (15-40, P = .001), respectively. During the first minutes of resuscitation, 93% of infants had an ECG heart rate compared with only 56% for PO. Early application of ECG electrodes during infant resuscitation can provide the resuscitation team with a continuous audible heart rate, and its use may improve the timeliness of appropriate critical interventions.
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The effects of oxytocin and atosiban on the modulation of heart rate in pregnant women.
Weissman, Amir; Tobia, Rana Swed; Burke, Yechiel Z; Maxymovski, Olga; Drugan, Arie
2017-02-01
To evaluate autonomic modulation of heart rate in pregnant women treated with oxytocin to induce labor and with atosiban (an oxytocin antagonist) to arrest preterm labor. A prospective study with two cohorts: 14 pregnant women treated with atosiban for premature uterine contractions, and 28 women undergoing induction of labor with oxytocin. Computerized analyses of the electrocardiogram were performed with spectral and nonlinear dynamic analyses. Atosiban did not alter any of the variables associated with heart rate variability, whereas oxytocin showed a dose-dependent decrease in heart rate (p < 0.05) and a significant increase in all spectral variables studied (p < 0.01). Atosiban has no adverse effects on the cardiovascular system or the modulation of heart rate. Oxytocin, on the other hand, can cause a dose-dependent bradycardic effect and an increase in the spectral power, thus should be used with caution in certain pregnant women.
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Heart rate and blood pressure variabilities in salt-sensitive hypertension.
Piccirillo, G; Bucca, C; Durante, M; Santagada, E; Munizzi, M R; Cacciafesta, M; Marigliano, V
1996-12-01
In salt-sensitive hypertension, a high sodium intake causes plasma catecholamines to rise and pulmonary baroreceptor plasticity to fall. In salt-sensitive and salt-resistant hypertensive subjects during low and high sodium intakes, we studied autonomic nervous system activity by power spectral analysis of heart rate and arterial pressure variabilities and baroreceptor sensitivity. In all subjects, high sodium intake significantly enhanced the low-frequency power of heart rate and arterial pressures at rest and after sympathetic stress. It also increased heart rate and arterial pressure variabilities. During high sodium intake, salt-sensitive hypertensive subjects had significantly higher low-frequency powers of systolic arterial pressure (7.5 mm Hg2, P < .05) and of heart rate at rest (59.2 +/- 2.4 normalized units [NU], P < .001) than salt-resistant subjects (6.6 +/- 0.3 mm Hg2, 55.0 +/- 3.2 NU) and normotensive control subjects (5.1 +/- 0.5 mm Hg2, 41.6 +/- 2.9 NU). In salt-sensitive subjects, low sodium intake significantly reduced low-frequency normalized units (P < .001) and the ratio of low- to high-power frequency (P < .001). High-sodium intake significantly increased baroreflex sensitivity in control subjects (from 10.0 +/- 0.7 to 17.5 +/- 0.7 ms/mm Hg, P < .001) and salt-resistant subjects (from 6.9 +/- 0.7 to 13.9 +/- 0.9, P < .05) but not in salt-sensitive subjects (7.4 +/- 0.3 to 7.9 +/- 0.4). In conclusion, a high sodium intake markedly enhances cardiac sympathetic activity in salt-sensitive and salt-resistant hypertension. In contrast, although reduced sodium intake lowers arterial pressure and sympathetic activity, it does so only in salt-sensitive subjects. Hence, in salt-resistant subjects, neither arterial pressure nor sympathetic activity depends on salt intake. During a high sodium intake in normotensive subjects and salt-resistant hypertensive subjects, increased sympathetic activity is probably compensated by enhanced baroreflex sensitivity.
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Sleep Wakefulness Determinations From Heart Rate Data. Volume III.
1977-05-31
differentiating It from states such as coma, trance, and anesthesia . The study of the phenomena of sleep has occupied researchers for many years...pressure and heart rate in the rabbit during animal hypnosis . Electroencephalog. Clln. Neurophslol., 37:231-237, 1974. 19. Clausen, J., Sersen, E.A
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Effects of changes in vertical occlusal dimension on heart rate fluctuations in guinea pigs.
Taga, Hitoshi; Azuma, Yukio; Maehara, Kiyoshi; Nomura, Shuichi
2012-01-01
We have previously reported that the decrease of the vertical occlusal dimension (VOD) led to heart failure and abnormalities in creatine phosphokinase (CPK) in guinea pigs. In the present study, we investigated the autonomic activity and the origin of the abnormality in CPK under different occlusal conditions. Guinea pigs were separated into the following five groups: untreated control, reduced VOD, slit, restored VOD and increased VOD groups and compared for their electrocardiogram and heart rate fluctuations for two weeks using Fluclet, computer software. The control group revealed no changes in heart rate fluctuations or posture. The reduced VOD group exhibited a two-phase wave of heart rate fluctuations, with the first peak 0-2 days after teeth grinding, and the second peak starting from 4 days after teeth grinding until sudden death (usually 12th day), accompanied by head drop. The slit and the restored VOD groups exhibited only the first peak. The increased VOD group, with approximately 3 mm-thick acrylic pellets bonded to the posterior teeth, showed no heart rate fluctuations. Body weight loss was most prominent in the reduced VOD group, and became much milder in the order of increased VOD, restored and slit groups. The reduced VOD group exhibited transient elevation of skeletal muscle type of CPK isozyme activity within two days after treatment. The present study suggests that the first peak of heart rate fluctuations is caused by pulpal stimulation, and the second peak by excessive contraction (excessive excitation of the motor output system and the autonomic nervous system) of the masticatory muscles. On the other hand, increased VOD did not influence either the motor or the autonomic nervous system.
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Ultrasound transducer positioning aid for fetal heart rate monitoring.
Hamelmann, Paul; Kolen, Alex; Schmitt, Lars; Vullings, Rik; van Assen, Hans; Mischi, Massimo; Demi, Libertario; van Laar, Judith; Bergmans, Jan
2016-08-01
Fetal heart rate (fHR) monitoring is usually performed by Doppler ultrasound (US) techniques. For reliable fHR measurements it is required that the fetal heart is located within the US beam. In clinical practice, clinicians palpate the maternal abdomen to identify the fetal presentation and then the US transducer is fixated on the maternal abdomen where the best fHR signal can be obtained. Finding the optimal transducer position is done by listening to the strength of the Doppler audio output and relying on a signal quality indicator of the cardiotocographic (CTG) measurement system. Due to displacement of the US transducer or displacement of the fetal heart out of the US beam, the fHR signal may be lost. Therefore, it is often necessary that the obstetrician repeats the tedious procedure of US transducer positioning to avoid long periods of fHR signal loss. An intuitive US transducer positioning aid would be highly desirable to increase the work flow for the clinical staff. In this paper, the possibility to determine the fetal heart location with respect to the transducer by exploiting the received signal power in the transducer elements is shown. A commercially available US transducer used for fHR monitoring is connected to an US open platform, which allows individual driving of the elements and raw US data acquisition. Based on the power of the received Doppler signals in the transducer elements, the fetal heart location can be estimated. A beating fetal heart setup was designed and realized for validation. The experimental results show the feasibility of estimating the fetal heart location with the proposed method. This can be used to support clinicians in finding the optimal transducer position for fHR monitoring more easily.
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Segerståhl, Katarina; Oinas-Kukkonen, Harri
2011-12-01
Various personal monitoring technologies have been introduced for supporting regular physical activity, which is of critical importance in reducing the risks of several chronic diseases. Recent studies suggest that combining multiple modes of delivery, such as text messages and mobile monitoring devices with web applications, holds potential for effectively supporting physical exercise. Of particular interest is how the functionality and content of these systems should be distributed across the different modes for successful outcomes. The aim of this study was to: (a) investigate how users incorporate a system employing two modes of delivery - a wearable heart rate monitor and a web service - into their training and (b) to analyze benefits and limitations in personal exercise monitoring and how they relate to the different modes in use. A qualitative field study employing diaries and semi-structured interviews was carried out with 30 participants who used a heart rate monitoring system comprising a wearable heart rate monitor, Polar FT60 and a web service, Polar Personal Trainer for a period of 21 days. The data were systematically analyzed to identify specific benefits and limitations associated with the system characteristics and modes as perceived by the end-users. The benefits include supporting exploratory learning, controlling target behavior, rectifying behaviors, motivation and logging support. The limitations are associated with information for validating the system, virtual coaching, task-technology fit, data integrity and privacy concerns. Mobile interfaces enable exploratory learning and controlling of target behaviors in situ, while web services can effectively support users' need for cognition within the early stages of adoption and long-term training with intelligent coaching functionality. This study explains several benefits and limitations in personal exercise monitoring. These can be addressed with crossmedial design, i.e., strategic distribution
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Abreu, José Sebastião de; Rocha, Eduardo Arrais; Machado, Isadora Sucupira; Parahyba, Isabelle O; Rocha, Thais Brito; Paes, Fernando José Villar Nogueira; Diogenes, Tereza Cristina Pinheiro; Abreu, Marília Esther Benevides de; Farias, Ana Gardenia Liberato Ponte; Carneiro, Marcia Maria; Paes, José Nogueira
2017-05-01
Normal coronary flow velocity reserve (CFVR) (≥ 2) obtained in the left anterior descending coronary artery (LAD) from transthoracic echocardiography is associated with a good prognosis, but there is no study correlating CFVR with submaximal target heart rate (HR). To evaluate the prognostic value of CFVR obtained in the LAD of patients with preserved (>50%) left ventricular ejection fraction (LVEF) who completed a dobutamine stress echocardiography (DSE), considering target HR. Prospective study of patients with preserved LVEF and CFVR obtained in the LAD who completed DSE. In Group I (GI = 31), normal CFVR was obtained before achieving target HR, and, in Group II (GII = 28), after that. Group III (G III=24) reached target HR, but CFVR was abnormal. Death, acute coronary insufficiency, coronary intervention, coronary angiography without further intervention, and hospitalization were considered events. In 28 ± 4 months, there were 18 (21.6%) events: 6% (2/31) in GI, 18% (5/28) in GII, and 46% (11/24) in GIII. There were 4 (4.8%) deaths, 6 (7.2%) coronary interventions and 8 (9.6%) coronary angiographies without further intervention. In event-free survival by regression analysis, GIII had more events than GI (p < 0.001) and GII (p < 0.045), with no difference between GI and GII (p = 0.160). After adjustment, the only difference was between GIII and GI (p = 0.012). In patients with preserved LVEF and who completed their DSE, normal CFVR obtained before achieving target HR was associated with better prognosis. A reserva de velocidade de fluxo coronariano (RVFC) adequada (≥ 2) obtida na artéria descendente anterior (ADA) através do ecocardiograma transtorácico associa-se a bom prognóstico, mas não há estudo correlacionando-a com a frequência cardíaca (FC) alvo (submáxima). Avaliar o valor prognóstico da RVFC obtida na ADA de pacientes com fração de ejeção do ventrículo esquerdo (FEVE) preservada (>50%) e ecocardiograma sob estresse com dobutamina
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Effect of mobile phone radiation on heart rate variability.
Ahamed, V I Thajudin; Karthick, N G; Joseph, Paul K
2008-06-01
The rapid increase in the use of mobile phones (MPs) in recent years has raised the problem of health risk connected with high-frequency electromagnetic fields. There are reports of headache, dizziness, numbness in the thigh, and heaviness in the chest among MP users. This paper deals with the neurological effect of electromagnetic fields radiated from MPs, by studies on heart rate variability (HRV) of 14 male volunteers. As heart rate is modulated by the autonomic nervous system, study of HRV can be used for assessing the neurological effect. The parameters used in this study for quantifying the effect on HRV are scaling exponent and sample entropy. The result indicates an increase in both the parameters when MP is kept close to the chest and a decrease when kept close to the head. MP has caused changes in HRV indices and the change varied with its position, but the changes cannot be considered significant as the p values are high.
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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.
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Ivabradine in acute coronary syndromes: Protection beyond heart rate lowering.
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.
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Retrospective study of the effect of remifentanil use during labor on fetal heart rate patterns.
Boterenbrood, Danne; Wassen, Martine M; Visser, Gerard H A; Nijhuis, Jan G
2018-01-01
To investigate possible associations between remifentanil and the appearance of sinusoidal heart rate patterns in fetuses, and neonatal outcomes. The present retrospective cohort study included data from patients at over 37 weeks of singleton or multiple pregnancies attending Zuyderland Medical Center, Sittard, the Netherlands, in labor between June 1, and August 31, 2015. Patient data were stratified by whether remifentanil was administered during delivery (remifentanil group) or not (control group), and fetal heart rate tracings were reviewed to identify sinusoidal heart rate patterns. The neonatal outcomes compared were 5-minute Apgar scores and umbilical artery pH. There were 119 patients included in the study; 60 in the remifentanil group and 59 in the control group. Tracings from 20 (33%) patients in the remifentanil group exhibited a sinusoidal heart rate pattern after remifentanil administration, compared with 5 (8%) patients in the control group (P=0.001). The median time before the onset of sinusoidal patterns after remifentanil administration was 12 minutes. No adverse neonatal outcomes were recorded in either group. Remifentanil use during labor was associated with the occurrence of sinusoidal heart rate patterns in the fetus; this was not associated with adverse neonatal outcomes. © 2017 International Federation of Gynecology and Obstetrics.
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Quantifying the Interactions between Maternal and Fetal Heart Rates by Transfer Entropy.
Marzbanrad, Faezeh; Kimura, Yoshitaka; Palaniswami, Marimuthu; Khandoker, Ahsan H
2015-01-01
Evidence of the short term relationship between maternal and fetal heart rates has been found in previous studies. However there is still limited knowledge about underlying mechanisms and patterns of the coupling throughout gestation. In this study, Transfer Entropy (TE) was used to quantify directed interactions between maternal and fetal heart rates at various time delays and gestational ages. Experimental results using maternal and fetal electrocardiograms showed significant coupling for 63 out of 65 fetuses, by statistically validating against surrogate pairs. Analysis of TE showed a decrease in transfer of information from fetus to the mother with gestational age, alongside the maturation of the fetus. On the other hand, maternal to fetal TE was significantly greater in mid (26-31 weeks) and late (32-41 weeks) gestation compared to early (16-25 weeks) gestation (Mann Whitney Wilcoxon (MWW) p<0.05). TE further increased from mid to late, for the fetuses with RMSSD of fetal heart rate being larger than 4 msec in the late gestation. This difference was not observed for the fetuses with smaller RMSSD, which could be associated with the quiet sleep state. Delay in the information transfer from mother to fetus significantly decreased (p = 0.03) from mid to late gestation, implying a decrease in fetal response time. These changes occur concomitant with the maturation of the fetal sensory and autonomic nervous systems with advancing gestational age. The effect of maternal respiratory rate derived from maternal ECG was also investigated and no significant relationship was found between breathing rate and TE at any lag. In conclusion, the application of TE with delays revealed detailed information on the fetal-maternal heart rate coupling strength and latency throughout gestation, which could provide novel clinical markers of fetal development and well-being.
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Quantifying the Interactions between Maternal and Fetal Heart Rates by Transfer Entropy
Marzbanrad, Faezeh; Kimura, Yoshitaka; Palaniswami, Marimuthu; Khandoker, Ahsan H.
2015-01-01
Evidence of the short term relationship between maternal and fetal heart rates has been found in previous studies. However there is still limited knowledge about underlying mechanisms and patterns of the coupling throughout gestation. In this study, Transfer Entropy (TE) was used to quantify directed interactions between maternal and fetal heart rates at various time delays and gestational ages. Experimental results using maternal and fetal electrocardiograms showed significant coupling for 63 out of 65 fetuses, by statistically validating against surrogate pairs. Analysis of TE showed a decrease in transfer of information from fetus to the mother with gestational age, alongside the maturation of the fetus. On the other hand, maternal to fetal TE was significantly greater in mid (26–31 weeks) and late (32–41 weeks) gestation compared to early (16–25 weeks) gestation (Mann Whitney Wilcoxon (MWW) p<0.05). TE further increased from mid to late, for the fetuses with RMSSD of fetal heart rate being larger than 4 msec in the late gestation. This difference was not observed for the fetuses with smaller RMSSD, which could be associated with the quiet sleep state. Delay in the information transfer from mother to fetus significantly decreased (p = 0.03) from mid to late gestation, implying a decrease in fetal response time. These changes occur concomitant with the maturation of the fetal sensory and autonomic nervous systems with advancing gestational age. The effect of maternal respiratory rate derived from maternal ECG was also investigated and no significant relationship was found between breathing rate and TE at any lag. In conclusion, the application of TE with delays revealed detailed information on the fetal-maternal heart rate coupling strength and latency throughout gestation, which could provide novel clinical markers of fetal development and well-being. PMID:26701122
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An automatic method to calculate heart rate from zebrafish larval cardiac videos.
Kang, Chia-Pin; Tu, Hung-Chi; Fu, Tzu-Fun; Wu, Jhe-Ming; Chu, Po-Hsun; Chang, Darby Tien-Hao
2018-05-09
Zebrafish is a widely used model organism for studying heart development and cardiac-related pathogenesis. With the ability of surviving without a functional circulation at larval stages, strong genetic similarity between zebrafish and mammals, prolific reproduction and optically transparent embryos, zebrafish is powerful in modeling mammalian cardiac physiology and pathology as well as in large-scale high throughput screening. However, an economical and convenient tool for rapid evaluation of fish cardiac function is still in need. There have been several image analysis methods to assess cardiac functions in zebrafish embryos/larvae, but they are still improvable to reduce manual intervention in the entire process. This work developed a fully automatic method to calculate heart rate, an important parameter to analyze cardiac function, from videos. It contains several filters to identify the heart region, to reduce video noise and to calculate heart rates. The proposed method was evaluated with 32 zebrafish larval cardiac videos that were recording at three-day post-fertilization. The heart rate measured by the proposed method was comparable to that determined by manual counting. The experimental results show that the proposed method does not lose accuracy while largely reducing the labor cost and uncertainty of manual counting. With the proposed method, researchers do not have to manually select a region of interest before analyzing videos. Moreover, filters designed to reduce video noise can alleviate background fluctuations during the video recording stage (e.g. shifting), which makes recorders generate usable videos easily and therefore reduce manual efforts while recording.
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Heart rate variability (HRV) in kidney failure: measurement and consequences of reduced HRV.
Ranpuria, Reena; Hall, Martica; Chan, Chris T; Unruh, Mark
2008-02-01
A common cause of death in end-stage renal disease (ESRD) patients on dialysis is sudden cardiac death (SCD). Compared to the general population, the percentage of cardiovascular deaths that are attributed to SCD is higher in patients treated by dialysis. While coronary artery disease (CAD) is the predominant cause of SCD in dialysis patients, reduced heart rate variability (HRV) may play a role in the higher risk of SCD among other risk factors. HRV refers to beat-to-beat alterations in heart rate as measured by periodic variation in the R-R interval. HRV provides a non-invasive method for investigating autonomic input into the heart. It quantifies the amount by which the R-R interval or heart rate changes from one cardiac cycle to the next. The autonomic nervous system transmits impulses from the central nervous system to peripheral organs and is responsible for controlling the heart rate, blood pressure and respiratory activity. In normal individuals, without cardiac disease, the heart rate has a high degree of beat-to-beat variability. HRV fluctuates with respiration: it increases with inspiration and decreases with expiration and is primarily mediated by parasympathetic activity. HRV has been used to evaluate and quantify the cardiac risk associated with a variety of conditions including cardiac disorders, stroke, multiple sclerosis and diabetes. In this narrative review, we will examine the association between HRV and SCD. This report explains the measurement of HRV and the consequences of reduced HRV in the general population and dialysis patients. Lastly, this review will outline the possible use of HRV as a clinical predictor for SCD in the dialysis population. The current understanding of SCD based on HRV findings among the ESRD population support the use of more aggressive treatment of CAD; greater use of angiotensin converting enzyme inhibitor (ACE-i)/angiotensin receptor blockers (ARBs) and beta-blockers and more frequent and/or nocturnal haemodialysis
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Temporal discounting and heart rate reactivity to stress.
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.
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Heart rate variability (HRV) during virtual reality immersion
Malińska, Marzena; Zużewicz, Krystyna; Bugajska, Joanna; Grabowski, Andrzej
2015-01-01
The goal of the study was assessment of the hour-long training involving handling virtual environment (sVR) and watching a stereoscopic 3D movie on the mechanisms of autonomic heart rate (HR) regulation among the subjects who were not predisposed to motion sickness. In order to exclude predispositions to motion sickness, all the participants (n=19) underwent a Coriolis test. During an exposure to 3D and sVR the ECG signal was continuously recorded using the Holter method. For the twelve consecutive 5-min epochs of ECG signal, the analysis of heart rate variability (HRV) in time and frequency domains was conducted. After 30 min from the beginning of the training in handling the virtual workstation a significant increase in LF spectral power was noted. The values of the sympathovagal LF/HF index while sVR indicated a significant increase in sympathetic predominance in four time intervals, namely between the 5th and the 10th minute, between the 15th and the 20th minute, between the 35th and 40th minute and between the 55th and the 60th minute of exposure. PMID:26327262
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Effect of Methamphetamine Dependence on Heart Rate Variability
Henry, Brook L.; Minassian, Arpi; Perry, William
2010-01-01
Background Methamphetamine (METH) is an increasing popular and highly addictive stimulant associated with autonomic nervous system (ANS) dysfunction, cardiovascular pathology, and neurotoxicity. Heart rate variability (HRV) has been used to assess autonomic function and predict mortality in cardiac disorders and drug intoxication, but has not been characterized in METH use. We recorded HRV in a sample of currently abstinent individuals with a history of METH dependence compared to age- and gender-matched drug-free comparison subjects. Method HRV was assessed using time domain, frequency domain, and nonlinear entropic analyses in 17 previously METH-dependent and 21 drug-free comparison individuals during a 5 minute rest period. Results The METH-dependent group demonstrated significant reduction in HRV, reduced parasympathetic activity, and diminished heartbeat complexity relative to comparison participants. More recent METH use was associated with increased sympathetic tone. Conclusion Chronic METH exposure may be associated with decreased HRV, impaired vagal function, and reduction in heart rate complexity as assessed by multiple methods of analysis. We discuss and review evidence that impaired HRV may be related to the cardiotoxic or neurotoxic effects of prolonged METH use. PMID:21182570
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Job strain and resting heart rate: a cross-sectional study in a Swedish random working sample.
Eriksson, Peter; Schiöler, Linus; Söderberg, Mia; Rosengren, Annika; Torén, Kjell
2016-03-05
Numerous studies have reported an association between stressing work conditions and cardiovascular disease. However, more evidence is needed, and the etiological mechanisms are unknown. Elevated resting heart rate has emerged as a possible risk factor for cardiovascular disease, but little is known about the relation to work-related stress. This study therefore investigated the association between job strain, job control, and job demands and resting heart rate. We conducted a cross-sectional survey of randomly selected men and women in Västra Götalandsregionen, Sweden (West county of Sweden) (n = 1552). Information about job strain, job demands, job control, heart rate and covariates was collected during the period 2001-2004 as part of the INTERGENE/ADONIX research project. Six different linear regression models were used with adjustments for gender, age, BMI, smoking, education, and physical activity in the fully adjusted model. Job strain was operationalized as the log-transformed ratio of job demands over job control in the statistical analyses. No associations were seen between resting heart rate and job demands. Job strain was associated with elevated resting heart rate in the unadjusted model (linear regression coefficient 1.26, 95 % CI 0.14 to 2.38), but not in any of the extended models. Low job control was associated with elevated resting heart rate after adjustments for gender, age, BMI, and smoking (linear regression coefficient -0.18, 95 % CI -0.30 to -0.02). However, there were no significant associations in the fully adjusted model. Low job control and job strain, but not job demands, were associated with elevated resting heart rate. However, the observed associations were modest and may be explained by confounding effects.
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Fabre, Claudine; Chehere, Baptiste; Bart, Frédéric; Mucci, Patrick; Wallaert, Benoit; Grosbois, Jean Marie
2017-01-01
It has been scientifically proven that pulmonary rehabilitation improves exercise tolerance and facilitates the carrying out of daily physical activities. To optimize the physical and physiological benefits, it is necessary to individualize the training intensity for each patient. The aim of this study is to compare the heart rate (HR) responses to three exercise modalities measuring aerobic fitness in chronic obstructive pulmonary disease patients, in order to easily prescribe individual target HRs for endurance training. Fifty COPD patients (mean age: 60.1±8.5 years) were included in the study. Each patient carried out a cardiopulmonary exercise test, a 6-minute walk test (6MWT) and a 6-minute stepper test (6MST). During these tests, HR was recorded continuously. After the cardiopulmonary exercise test, the HR was noted at the ventilatory threshold (VT) and at the end of the two exercise field tests (6MWT peak and 6MST peak ). The values of the HR during the last 3 minutes of both field tests were averaged (6MWT 456 and 6MST 456 ). Finally, the HR at 60% of the HR reserve was calculated with the values of the HR measured during 6MWT and 6MST (HRr 60%walk , HRr 60%step ). The HRs measured during the 6MST were significantly higher than those measured during the 6MWT. The HRr 60%step was not significantly different from 6MWT 456 and 6MWT peak HR ( P =0.51; P =0.48). A significant correlation was observed between 6MWT 456 and 6MWT peak ( r =0.58). The 6MWT 456 and 6MWT peak HR were correlated with HRr 60%step ( r =0.68 and r =0.62). The VT could be determined in 28 patients. The HR VT was not different from 6MWT 456 , 6MWT peak , and HRr 60%step ( P =0.57, P =0.41 and P =0.88) and was correlated to 6MWT 456 , 6MWT peak , and HRr 60%step ( r =0.45, r =0.40, r =0.48). An individualized target HR for endurance training can be prescribed from the HR measured during routine tests, such as 6MWT or 6MST.
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Fabre, Claudine; Chehere, Baptiste; Bart, Frédéric; Mucci, Patrick; Wallaert, Benoit; Grosbois, Jean Marie
2017-01-01
Background It has been scientifically proven that pulmonary rehabilitation improves exercise tolerance and facilitates the carrying out of daily physical activities. To optimize the physical and physiological benefits, it is necessary to individualize the training intensity for each patient. The aim of this study is to compare the heart rate (HR) responses to three exercise modalities measuring aerobic fitness in chronic obstructive pulmonary disease patients, in order to easily prescribe individual target HRs for endurance training. Patients and method Fifty COPD patients (mean age: 60.1±8.5 years) were included in the study. Each patient carried out a cardiopulmonary exercise test, a 6-minute walk test (6MWT) and a 6-minute stepper test (6MST). During these tests, HR was recorded continuously. After the cardiopulmonary exercise test, the HR was noted at the ventilatory threshold (VT) and at the end of the two exercise field tests (6MWTpeak and 6MSTpeak). The values of the HR during the last 3 minutes of both field tests were averaged (6MWT456 and 6MST456). Finally, the HR at 60% of the HR reserve was calculated with the values of the HR measured during 6MWT and 6MST (HRr60%walk, HRr60%step). Results The HRs measured during the 6MST were significantly higher than those measured during the 6MWT. The HRr60%step was not significantly different from 6MWT456 and 6MWTpeak HR (P=0.51; P=0.48). A significant correlation was observed between 6MWT456 and 6MWTpeak (r=0.58). The 6MWT456 and 6MWTpeak HR were correlated with HRr60%step (r=0.68 and r=0.62). The VT could be determined in 28 patients. The HRVT was not different from 6MWT456, 6MWTpeak, and HRr60%step (P=0.57, P=0.41 and P=0.88) and was correlated to 6MWT456, 6MWTpeak, and HRr60%step (r=0.45, r=0.40, r=0.48). Conclusion An individualized target HR for endurance training can be prescribed from the HR measured during routine tests, such as 6MWT or 6MST. PMID:28553100
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Multiscale power analysis for heart rate variability
NASA Astrophysics Data System (ADS)
Zeng, Peng; Liu, Hongxing; Ni, Huangjing; Zhou, Jing; Xia, Lan; Ning, Xinbao
2015-06-01
We first introduce multiscale power (MSP) method to assess the power distribution of physiological signals on multiple time scales. Simulation on synthetic data and experiments on heart rate variability (HRV) are tested to support the approach. Results show that both physical and psychological changes influence power distribution significantly. A quantitative parameter, termed power difference (PD), is introduced to evaluate the degree of power distribution alteration. We find that dynamical correlation of HRV will be destroyed completely when PD>0.7.
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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.
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Inagaki, Takeshi; Terada, Jiro; Yahaba, Misuzu; Kawata, Naoko; Jujo, Takayuki; Nagashima, Kengo; Sakao, Seiichiro; Tanabe, Nobuhiro; Tatsumi, Koichiro
2018-05-01
The 6-min walk test (6MWT) is commonly performed to assess functional status in patients with chronic thromboembolic pulmonary hypertension. However, changes in heart rate and oxygen saturation (S pO 2 ) patterns during 6MWT in patients with chronic thromboembolic pulmonary hypertension remain unclear. Thirty-one subjects with chronic thromboembolic pulmonary hypertension were retrospectively evaluated to examine the relationships between the change in heart rate (Δheart rate), heart rate acceleration time, slope of heart rate acceleration, heart rate recovery during the first minute after 6MWT (HRR1), change in S pO 2 (ΔS pO 2 ), S pO 2 reduction time, and S pO 2 recovery time during 6MWT, and the severity of pulmonary hemodynamics assessed by right heart catheterization and echocardiography. Subjects with severe chronic thromboembolic pulmonary hypertension had significantly longer heart rate acceleration time (144.9 ± 63.9 s vs 96.0 ± 42.5 s, P = .033), lower Δheart rate (47.4 ± 16.9 vs 61.8 ± 13.6 beats, P = .02), and lower HRR1 (13.3 ± 9.0 beats vs 27.1 ± 9.2 beats, P < .001) compared to subjects with mild chronic thromboembolic pulmonary hypertension. Subjects with severe chronic thromboembolic pulmonary hypertension also had significantly longer S pO 2 reduction time (178.3 ± 70.3 s vs 134.3 ± 58.4 s, P = .03) and S pO 2 recovery time (107.6 ± 35.3 s vs 69.8 ± 32.7 s, P = .004) than did subjects with mild chronic thromboembolic pulmonary hypertension. Multivariate linear regression analysis showed only mean pulmonary arterial pressure independently was associated with heart rate acceleration time and slope of heart rate acceleration. Heart rate and S pO 2 change patterns during 6MWT are predominantly associated with pulmonary hemodynamics in subjects with chronic thromboembolic pulmonary hypertension. Evaluating heart rate and S pO 2 change patterns during 6MWT may serve as a safe and convenient way to follow the change in pulmonary hemodynamics
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Effects and after-effects of chewing gum on vigilance, heart rate, EEG and mood.
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.
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Combinatorial effect of nicotine and black tea on heart rate variability: Useful or harmful?
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 < .05), and low-frequency power/high-frequency power (LF/HF) ratio in the nicotine and tea + nicotine groups was significantly less than control group (P < .05). LF values did not differ significantly among groups. Mean of standard deviation of normal RR intervals (SDNN) and square root of the mean squared differences of successive RR intervals (RMSSD) increased significantly in tea, nicotine and tea + nicotine groups in comparison with control group (P < .05) Overall, 4-week administration of black tea, 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.
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State Anxiety and Nonlinear Dynamics of Heart Rate Variability in Students.
Dimitriev, Dimitriy A; Saperova, Elena V; Dimitriev, Aleksey D
2016-01-01
Clinical and experimental research studies have demonstrated that the emotional experience of anxiety impairs heart rate variability (HRV) in humans. The present study investigated whether changes in state anxiety (SA) can also modulate nonlinear dynamics of heart rate. A group of 96 students volunteered to participate in the study. For each student, two 5-minute recordings of beat intervals (RR) were performed: one during a rest period and one just before a university examination, which was assumed to be a real-life stressor. Nonlinear analysis of HRV was performed. The Spielberger's State-Trait Anxiety Inventory was used to assess the level of SA. Before adjusting for heart rate, a Wilcoxon matched pairs test showed significant decreases in Poincaré plot measures, entropy, largest Lyapunov exponent (LLE), and pointwise correlation dimension (PD2), and an increase in the short-term fractal-like scaling exponent of detrended fluctuation analysis (α1) during the exam session, compared with the rest period. A Pearson analysis indicated significant negative correlations between the dynamics of SA and Poincaré plot axes ratio (SD1/SD2), and between changes in SA and changes in entropy measures. A strong negative correlation was found between the dynamics of SA and LLE. A significant positive correlation was found between the dynamics of SA and α1. The decreases in Poincaré plot measures (SD1, complex correlation measure), entropy measures, and LLE were still significant after adjusting for heart rate. Corrected α1 was increased during the exam session. As before, the dynamics of adjusted LLE was significantly correlated with the dynamics of SA. The qualitative increase in SA during academic examination was related to the decrease in the complexity and size of the Poincaré plot through a reduction of both the interbeat interval and its variation.
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State Anxiety and Nonlinear Dynamics of Heart Rate Variability in Students
Dimitriev, Aleksey D.
2016-01-01
Objectives Clinical and experimental research studies have demonstrated that the emotional experience of anxiety impairs heart rate variability (HRV) in humans. The present study investigated whether changes in state anxiety (SA) can also modulate nonlinear dynamics of heart rate. Methods A group of 96 students volunteered to participate in the study. For each student, two 5-minute recordings of beat intervals (RR) were performed: one during a rest period and one just before a university examination, which was assumed to be a real-life stressor. Nonlinear analysis of HRV was performed. The Spielberger’s State-Trait Anxiety Inventory was used to assess the level of SA. Results Before adjusting for heart rate, a Wilcoxon matched pairs test showed significant decreases in Poincaré plot measures, entropy, largest Lyapunov exponent (LLE), and pointwise correlation dimension (PD2), and an increase in the short-term fractal-like scaling exponent of detrended fluctuation analysis (α1) during the exam session, compared with the rest period. A Pearson analysis indicated significant negative correlations between the dynamics of SA and Poincaré plot axes ratio (SD1/SD2), and between changes in SA and changes in entropy measures. A strong negative correlation was found between the dynamics of SA and LLE. A significant positive correlation was found between the dynamics of SA and α1. The decreases in Poincaré plot measures (SD1, complex correlation measure), entropy measures, and LLE were still significant after adjusting for heart rate. Corrected α1 was increased during the exam session. As before, the dynamics of adjusted LLE was significantly correlated with the dynamics of SA. Conclusions The qualitative increase in SA during academic examination was related to the decrease in the complexity and size of the Poincaré plot through a reduction of both the interbeat interval and its variation. PMID:26807793