Use Of Heart Rate Variability Research Articles

Relationship Between Heart Rate Variability and Perceived Stress in Healthy College‐Aged Adults

Heart rate variability (HRV) is a measurement of how well the heart can adapt to change and is a function of the autonomic nervous system (ANS). HRV is determined by measuring the variations between each heartbeat; sympathetic input decreases HRV (less beat‐to‐beat variation) while parasympathetic input increases HRV (more beat‐to‐beat variation). We examined the relationship of HRV to the perceived amount of self‐reported stress in healthy college‐aged students (n=11) once a week over a 5‐week period (Elon IRB 17‐222). This population routinely vacillate between stressed and non‐stressed states. Students completed a Perceived Stress Scale followed by a 5 min ECG. The ECG was analyzed using AD Instruments software (Colorado Springs, CO). HRV data was generated for each individual and was compared to the perceived stress data. Chi‐square test of independence concluded that HRV and perceived stress are related factors (p= 0.03). These results indicate that HRV could be a valuable biological indicator of stress levels in young healthy individuals; however, multiple regression analysis of each individual generated R squared values ranging from 0.05–0.92 indicating a large degree of variability. Future research would examine the use of HRV as a biomarker for stress, as well as the lasting effects of stress on HRV.Support or Funding InformationElon Undergraduate Research ProgramThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Heart Rate Variability in Dental Science.

Dentistry has made progress as a profession by integration with both medicine and other human sciences, especially when it uses empirical metrics to study process and outcome variables. Notably, progress in our understanding of genomic, biomic, and other molecular biological phenomena has been valuable. As has been identified by Drury (1, 2), it is proposed in this commentary that the inclusion of heart rate variability (HRV) as a biomarker of health may further this integrative progress. HRV is derived by various linear and non-linear statistical analyses of the R-R, beat-to-beat ECG interval in microseconds. Over twenty three thousand reports are identified in a recent PubMed search of the term heart rate variability, most of which demonstrate HRV's sensitivity to a wide diversity of physical and psychosocial pathologies. The small literature of dental use of HRV in both assessment and treatment will be selectively reviewed and relevant exemplars for other important health applications of HRV will be discussed. This will lead to a proposed agenda for researching HRV's value to professional dentistry as a human health and wellness profession.

Cardiovascular clinical implications of heart rate variability

Heart rate variability (HRV) is one of the promising emerging noninvasive modalities that are extensively used nowadays in research and risk stratification of several diseases. Reduced HRV has been linked to several cardiovascular risk factors such as hypertension (HTN) and diabetes mellitus (DM) also; it has been linked and used for years now in the risk stratification of congestive heart failure, coronary artery disease (CAD), and acute myocardial infarction (AMI). Controversial data are present about the effect of coronary artery bypass graft (CABG) on HRV and the use of HRV for risk stratification in post-CABG patients while percutaneous coronary intervention was linked to a dramatic improvement in HRV and improved survival of CAD patients. Although experimental data are present correlating reduced HRV with increased risk for cardiovascular morbidity and mortality, extensive research is required for further implementation in daily clinical use. In this review, we will discuss the current cardiovascular clinical implications and highlight the limitations of usage and future perspective of HRV.

Heart Rate Variability in the Diagnostics and CPAP Treatment of Obstructive Sleep Apnea.

Obstructive sleep apnea (OSA) is the most common manifestation of sleep-related breathing disorders that are often accompanied by dysfunction of the autonomic nervous system. The main objective of the study was to assess the usefulness of heart rate variability (HRV) analysis in the diagnosis of patients with severe OSA and in the assessment of the effects of 3-month treatment with continuous positive airway pressure (CPAP). There were 54 patients enrolled in the study. The OSA group consisted of 39 patients suffering from severe OSA (apnea/hypopnea index >30/h), and the control group included 15 non-OSA patients with matched demographic characteristics and comorbidities. All patients underwent 24-h Holter electrocardiographic monitoring. HRV was analyzed using the time- and frequency-domains. We found that OSA patients had decreases in time-domains and increases in frequency-domains of HRV, compared to non-OSA controls, which strongly suggested a clinically disadvantageous shift in the balance of parasympathetic/sympathetic activity toward the latter. Further, CPAP treatment, partly, albeit significantly, reversed the OSA-induced changes in HRV. We conclude that HRV analysis may be of help in the diagnosis of OSA and in the monitoring of the effectiveness of treatment.

Clinical utility of heart rate variability during Head-up tilt test in subjects with chronic posttraumatic stress disorder

Posttraumatic stress disorder (PTSD) is characterized by psychophysiological abnormalities, such as an altered baseline heart rate and hyperarousal, implying dysfunctional arousal regulation. Heart rate variabilities (HRVs) is known to reflect autonomic nervous system activity. We examined the changes of HRVs in PTSD patients with head-up tilt position to closely investigate disease-specific changes in autonomic function in PTSD patients. Sixty-seven patients with PTSD and 72 patients without PTSD were assessed using the PTSD Checklist for DSM-5 (PCL-5) and psychiatric interview. Heart rate data including standard deviation of the NN intervals, the square root of the mean squared differences of successive NN intervals, log low-frequency and log high-frequency were collected for 10 min before and after tilting. Considering interactions between groups and head-up tilting, the head-up tilting induced reduction of the high-frequency component of HRVs was significantly greater in the PTSD group [F (1, 272) = 4.718, p = 0.031]. The change of HRVs in PTSD patients suggested the presence of autonomic dysfunction in despite of the posture.

Heart rate variability in neonatal patients with seizures

ObjectiveSeizures are frequently observed in neurological conditions affecting newborns. Since autonomic alterations are commonly associated with neonatal seizures (NS), we investigated the utility of heart rate variability (HRV) indexes of cardiac autonomic regulation for NS detection. MethodsHRV analysis was conducted on ECG tracings recorded during video-EEG monitoring in newborns with NS and matched-controls. The effects of gestational age on HRV were also evaluated. ResultsNewborns with NS showed lower resting state HRV compared to controls. Moreover, seizure episodes were characterized by a short-lasting increase in vagal indexes of HRV. Pre-term newborns with NS had a lower HRV than full-term at rest. In pre-term newborns, no changes in HRV were observed before and during NS. On the contrary, full-term newborns showed significantly higher HRV before and during NS compared to the respective baseline values. ConclusionOur data point to resting autonomic impairment in newborns with NS. In addition, an increment in HRV has been observed during NS only in full term newborns. SignificanceAlthough these findings do not allow validation of HRV measures for NS prediction and detection, they suggest that a putative protective vagal mechanism might be adopted when an advanced maturation of autonomic nervous system is achieved.

Variabilidade da frequência cardíaca em pacientes com dor lombar: uma revisão sistemática.

Introduo: A lombalgia se caracteriza como uma dor de origem multifatorial que pode resultar em alteraes no sistema nervoso autnomo. Estas alteraes so identificadas pelo aumento da modulao simptica cardaca levando a diminuio da variabilidade da frequncia cardaca (VFC). Objetivo: Realizar uma reviso literatura acerca do uso da VFC em pacientes com lombalgia. Mtodos: A busca sistemtica desse estudo foi conduzida atravs das bases de dados LILACS, PubMED, CINAHL e SciELO. Resultados: Foram includos na reviso apenas dez estudos que mostravam a relao entre a lombalgia e as respostas dos ndices da VFC. Destes, sete estudos relatam melhora/relao dos ndices da VFC com a lombalgia e outros estudos no mostram alterao das respostas. Concluso: Existem poucas evidncias apresentando a relao entre a lombalgia e as respostas dos ndices da VFC na literatura. Alm disso, os resultados se mostram inconclusivos, fato este que dificulta afirmar se h relao ou melhora dos ndices da VFC aps interveno em pacientes com lombalgia.

The Association Between Endurance Training and Heart Rate Variability: The Confounding Role of Heart Rate.

Heart rate variability (HRV) is a widely used marker of cardiac autonomic nervous activity (CANA). Changes in HRV with exercise training have often been interpreted as increases in vagal activity. HRV is strongly associated with heart rate, which in turn, is associated with heart size. There is strong evidence from basic studies that lower heart rate in response to exercise training is caused by morphological and electrical remodeling of the heart. In a cross-sectional study in participants of a 10 mile race, we investigated the influence of endurance exercise on HRV parameters independently of heart size and heart rate. One-hundred-and-seventy-two runners (52 females and 120 males) ranging from novice runners with a first participation to an endurance event to highly trained runners, with up to 15 h of training per week, were included in the analysis. R-R intervals were recorded by electrocardiography over 24 h. Left ventricular end diastolic volume indexed to body surface area (LVEDVI) was assessed by transthoracic echocardiography and peak oxygen consumption (VO2peak) by cardiopulmonary exercise testing. Exercise was quantified by VO2peak, training volume, and race performance. HRV was determined during deep sleep. HRV markers of vagal activity were moderately associated with exercise variables (standardized β = 0.28–0.40, all p < 0.01). These associations disappeared when controlling for heart rate and LVEDVI. Due to the intrinsic association between heart rate and HRV, conclusions based on HRV parameters do not necessarily reflect differences in CANA. Based on current evidence, we discourage the use of HRV as a marker of CANA when measuring the effect of chronic exercise.

Investigating the use of pre-training measures of autonomic regulation for assessing functional overreaching in endurance athletes

The use of heart rate variability (HRV) to inform daily training prescription is becoming common in endurance sport. Few studies, however, have investigated the use of pre-training HRV to predict decreased performance or altered exercising autonomic response, typical of functional overreaching (FOR). Further, a new cardiac vagal tone (ProCVT) technology purports to eliminate some of the noise associated with daily HRV, and therefore may be better at predicting same-day performance. The purpose of this investigation was to examine if changes to resting HRV and ProCVT were associated with alterations in performance, maximal heart rate (HRmax), or heart rate recovery (HRrec) in FOR athletes. Twenty-eight recreational cyclists and triathletes were assigned to experimental/control conditions and underwent: 1 week of reduced training, 3 weeks of overload (OL) or regular training (CON), and 1 week of recovery. Testing occurred following the reduced training week (T1), post-3 weeks of training (T2), and following the recovery week (T3). Measures of resting HRV/ProCVT were collected each testing session, followed by maximal incremental exercise tests with HRrec taken 60 s post-exercise. Performance decreased from T1 to T2 in the OL group vs. CON (Δ−9 ± 12 vs. Δ9 ± 11 W, P < .001), as did HRmax (Δ−8 ± 4 vs. Δ−2 ± 4 bpm, P < .001). HRrec increased from T1 to T2 in the OL group vs. CON (Δ10 ± 9 vs. Δ2 ± 5 beats/min, P < .01). HRV and ProCVT did not change in either group. Same-day resting autonomic measures are insufficient in predicting alterations to performance or exercising HR measures following overload training.

Autonomic Dysfunction in Neonates with Hypoxic Ischemic Encephalopathy Undergoing Therapeutic Hypothermia Impairs Physiological Responses to Routine Care Events

To evaluate whether infants with hypoxic-ischemic encephalopathy and evidence of autonomic dysfunction have aberrant physiological responses to care events that could contribute to evolving brain injury. Continuous tracings of heart rate (HR), blood pressure (BP), cerebral near infrared spectroscopy, and video electroencephalogram data were recorded from newborn infants with hypoxic-ischemic encephalopathy who were treated with hypothermia. Videos between 16 and 24 hours of age identified 99 distinct care events, including stimulating events (diaper changes, painful procedures), and vagal stimuli (endotracheal tube manipulations, pupil examinations). Pre-event HR variability was used to stratify patients into groups with impaired versus intact autonomic nervous system (ANS) function. Postevent physiological responses were compared between groups with the nearest mean classification approach. Infants with intact ANS had increases in HR/BP after stimulating events, whereas those with impaired ANS showed no change or decreased HR/BP. With vagal stimuli, the HR decreased in infants with intact ANS but changed minimally in those with impaired ANS. A pupil examination in infants with an intact ANS led to a stable or increased BP, whereas the BP decreased in the group with an impaired ANS. Near infrared spectroscopy measures of cerebral blood flow/blood volume increased after diaper changes in infants with an impaired ANS, but were stable or decreased in those with an intact ANS. HR variability metrics identified infants with impaired ANS function at risk for maladaptive responses to care events. These data support the potential use of HR variability as a real-time, continuous physiological biomarker to guide neuroprotective care in high-risk newborns.

Heart rate variability as predictive factor for sudden cardiac death.

Sudden cardiac death (SCD) represents about 25% of deaths in clinical cardiology. The identification of risk factors for SCD is the philosopher's stone of cardiology and the identification of non-invasive markers of risk of SCD remains one of the most important goals for the scientific community.The aim of this review is to analyze the state of the art around the heart rate variability (HRV) as a predictor factor for SCD.HRV is probably the most analyzed index in cardiovascular risk stratification technical literature, therefore an important number of models and methods have been developed.Nowadays, low HRV has been shown to be independently predictive of increased mortality in post- myocardial infarction patients, heart failure patients, in contrast with the data of the general population.Contrariwise, the relationship between HRV and SCD has received scarce attention in low-risk cohorts. Furthermore, in general population the attributable risk is modest and the cost/benefit ratio is not always convenient.The HRV evaluation could become an important tool for health status in risks population, even though the use of HRV alone for risk stratification of SCD is limited and further studies are needed.

Heart Rate Variability as a Biomarker for Predicting Stroke, Post-stroke Complications and Functionality.

Background:Heart rate variability (HRV) is a non-invasive measure of the function of the autonomic nervous system, and its dynamic nature may provide a means through which stroke and its associated complications may be predicted, monitored, and managed.Objective:The objective of this review is to identify and provide a critique on the most recent uses of HRV in stroke diagnosis/management and highlight areas that warrant further research.Methods:The MEDLINE, CINAHL, and OVID MEDLINE databases were canvassed using a systematic search strategy, for articles investigating the use of HRV in stroke diagnosis and management. Initial paper selections were based on title alone, and final paper inclusion was informed by a full-text critical appraisal.Results:The systematic search returned 98 records, of which 51 were unique. Following screening, 22 records were included in the final systematic review. The included papers provided some information regarding predicting incident stroke, which largely seems to be best predicted by time- and frequency-domain HRV parameters. Furthermore, post-stroke complications and functionality are similarly predicted by time- and frequency-domain parameters, as well as non-linear parameters in some instances.Conclusions:Current research provides good evidence that HRV parameters may have utility as a biomarker for stroke and for post-stroke complications and/or functionality. Future research would benefit from the integration of non-linear, and novel parameters, the hybridisation of HRV parameters, and the expansion of the utilisation of predictive regression and hazard modelling.

Heart Rate Variability: An Old Metric with New Meaning in the Era of Using mHealth technologies for Health and Exercise Training Guidance. Part Two: Prognosis and Training.

It has been demonstrated that heart rate variability (HRV) is predictive of all-cause and cardiovascular mortality using clinical ECG recordings. This is true for rest, exercise and ambulatory HRV clinical ECG device recordings in prospective cohorts. Recently, there has been a rapid increase in the use of mobile health technologies (mHealth) and commercial wearable fitness devices. Most of these devices use ECG or photo-based plethysmography and both are validated for providing accurate heart rate measurements. This offers the opportunity to make risk information from HRV more widely available. The physiology of HRV and the available technology by which it can be assessed has been summarised in Part 1 of this review. In Part 2 the association between HRV and risk stratification is addressed by reviewing the current evidence from data acquired by resting ECG, exercise ECG and medical ambulatory devices. This is followed by a discussion of the use of HRV to guide the training of athletes and as a part of fitness programmes.

Utility of Heart Rate Variability: Focusing on High and Low-frequency Components

Utility of Heart Rate Variability: Focusing on High and Low-frequency Components

Heart rate variability: implications for perioperative anesthesia care.

Heart rate variability (HRV) is a measure of the balance between both the parasympathetic and sympathetic nervous system and may provide useful information for anesthesia care providers. HRV may offer predictive information about critically ill and operative patients. Further, HRV collection provides real-time information of patient autonomic nervous system status and may allow tailoring of the analgesia for patients in the ICU and operating room. Reduced and abnormal resting HRV predict sudden and nonsudden cardiac death. Recent evidence shows that decreased HRV correlates with worsened outcomes in both trauma patients and patients with sepsis, as well as the risk of developing hypotension after induction of general anesthesia and placement of intrathecal local anesthesia. In addition, HRV appears to provide an accurate assessment of the nociception-analgesia balance in deeply sedated ICU patients and those under general anesthesia. No study has assessed the prognostic value of preoperative HRV in patients presenting for surgery. Use of HRV for patient risk stratification and intraoperative analgesia management may allow tailored perioperative care and improved outcomes. If intraoperative HRV data leads to decreased perioperative opioid use, opioid-related adverse events, a serious perioperative issue, may be decreased. Not applicable.

Predictors of aging based on the analysis of heart rate variability.

The current significant progress in the use of heart rate variability in the solution of many diagnostic and therapeutic problems is determined by the availability of standardized methods of measurement and physiological interpretation of heart rate variability indices on the one hand and the high technological level of state-of-the-art electronic measuring equipment that is used for automatic registration and computer processing of cardio-signals. A retrospective analysis of anonymized cardio screening results of 22,433 adult residents of 565 settlements (cities and villages) across all 20 administrative districts of the Khmelnytskyi Region (Ukraine) was conducted to find a statistically significant connection between individual heart rate variability parameters and the age of people. Primary statistical analysis and visualization showed a correlation between the selected heart rate variability parameters and the age and sex of the examined persons. The study found values of the predicted age slightly over estimation versus the actual age for very young test subjects and below estimation for elderly subjects. The use of neural network computations and the modification of the algorithm through the construction of individual training samples for different age intervals, and the creation of individual ensembles of classification neural networks, therefore achieved a prediction of the age of examined persons based on the values of their time and frequency domain heart rate variability indices, with 87% accuracy for women and 85% accuracy for men in the 66-85 years age interval and at least 85% for age groups across the entire sample.

Heart rate variability and salivary cortisol in very preterm children during school age

The autonomic nervous system (ANS) plays a major role in the human stress response and reflects physical and psychological adaptability to a changing environment. Long-term exposure to early life stressors may alter the function of the ANS. The present study examines differences in the ANS between children born very preterm and full-term as well as the association between the ANS and the hypothalamic-pituitary-adrenal (HPA) axis, the other main branch of the human stress system.Fifty-four healthy children born very preterm (<32nd gestational week) and 67 full-term children aged 7–12 years provided data for the present study. Polysomnography (PSG) assessments were obtained during a night at the children’s home in lying position at rest (wake) and during different sleep stages (stage 2 sleep, slow wave sleep, rapid-eye-movement sleep). Autonomic function was assessed by use of heart rate variability, specifically low frequency power (LF), high frequency power (HF), total spectral power (Tot Pow), and the LF/HF ratio. HPA axis activity was measured using salivary cortisol the next morning at awakening, 10, 20, and 30min later.Children born very preterm had lower LF/HF ratio during wake and stage 2 sleep compared to full-term children. Moreover, higher LF, Tot Pow, and LF/HF ratio during wake, stage 2 sleep, and REM sleep were related to more post-awakening cortisol secretion.The present study provides evidence on long-term ANS alterations after very preterm birth. Moreover, findings suggest a relation between the ANS and the HPA axis and therefore support the notion of mutual feedback between the two human stress systems.

Heart Rate Variability as a Feeding Intervention Outcome Measure in the Preterm Infant.

Feeding interventions for preterm infants aim to reduce the physiologic stress of feeding to promote growth. Heart rate variability (HRV) is a potential noninvasive measure of physiologic stress that may be useful for evaluating efficacy of feeding interventions. To evaluate whether HRV is a sensitive measure of physiologic stress compared with standard physiologic outcomes in the context of a feeding intervention study. This was a secondary analysis of a within-subjects, cross-over design study comparing usual care feeding with a gentle, coregulated (CoReg) feeding approach in 14 infants born less than 35 weeks' postmenstrual age. HRV indices were calculated from electrocardiogram data and compared with standard physiologic outcomes, including oxygen saturation (Spo2), respiratory rate (RR), apnea, heart rate (HR), and bradycardia. Data were analyzed using linear mixed modeling. Infants fed using the CoReg approach had fewer apneic events and higher RR, suggesting they were able to breathe more during feeding. No statistically significant differences were found in SpO2, HR, bradycardia, or high frequency power (the most commonly reported measure of HRV). Infants fed using the usual care approach had significantly higher SD12, a measure of HRV indicating randomness in the HR, which is a potential indicator of elevated stress. SD12 was more sensitive to stress than SpO2, HR, and bradycardia. The utility of HRV as a measure of feeding outcomes in clinical practice needs further exploration. Further exploration of HRV as an intervention outcome measure is needed, particularly evaluating nonlinear indices, such as SD12.

Validity of spectral analysis based on heart rate variability from 1-minute or less ECG recordings.

To broaden the utility of heart rate variability (HRV) in clinical medicine and mass screening, results based on shorter electrocardiogram (ECG) recordings require validation with those based on standard 5-minute recordings. We investigated the association between HRV variables obtained from 5-minute ECGs with those obtained from ECGs shorter than 5 minutes. Twenty-two participants aged 20-69 years underwent 5-minute resting ECG recordings in the supine position with natural breathing. Spectral analysis using MemCalc method was performed to calculate high-frequency (HF, which required at least 10 seconds) and low-frequency (LF, which required at least 30 seconds) components. Participants were not strictly preconditioned as in previous experimental studies in order to simulate a setting similar to that of a general health checkup. Associations of each variable between the 5-minute ECG recordings and those for shorter recordings were examined by Pearson's correlation coefficients and Bland-Altman plots. HF and LF components were log-transformed based on their distributions. Correlation coefficients between 5-minute data and shorter recordings in the supine position with natural breathing ranged from 0.80 to 0.91 (HF by 10-second recording, 0.80; LF by 30-second recording, 0.83, respectively). Bland-Altman plots showed that gaps between the values from both methods slightly increased as the HF and LF component values increased. Although slight proportional errors were possible, values from standard 5-minute and shorter recordings in the supine position were strongly correlated. Our findings suggest that shorter ECG data without strict preconditioning can be reliably used for spectral analysis.

Comparison between heart rate variability and pulse rate variability during different sleep stages for sleep apnea patients

The usefulness of heart rate variability (HRV) in the clinical research has been verified in numerous studies. However, it is controversy that using pulse rate variability (PRV) as a surrogate of HRV in different clinical applications. We aimed to investigate whether PRV extracted from finger pulse photoplethysmography (Pleth) signal could substitute HRV from ECG signal during different sleep stages by analyzing the common time-domain, frequency-domain and non-linear indices. Seventy-five sleep apnea patients were enrolled. For each patient, ECG and Pleth signals were simultaneously recorded for the whole night using Alice Sleepware Polysomnographic System and the sleep stage signals were automatically calculated by this System. Time-domain, frequency-domain and non-linear indices of both HRV and PRV were calculated for each sleep stage. Mann-Whitney U-test showed that for both time-domain and frequency-domain indices, there were no statistical differences between HRV and PRV results during all four sleep stages. For non-linear indices, sample entropy reported statistical differences between HRV and PRV results for N1, N2 and REM sleeps (all P< 0.01) whereas fuzzy measure entropy only reported statistical differences for REM sleep (P< 0.05). SDNN, LF and LF/HF indices decreased for both HRV and PRV with the sleep deepening while HF and non-linear indices increased. In addition, there were strong and significant correlation between HRV and PRV indices during all four sleep stages (all P< 0.01). PRV measurement could present the similar results as HRV analysis for sleep apnea patients during different sleep stages.