Heart Rate Variability Recordings Research Articles

Analysis of indicators of short recording of heart rate variability in comorbid patients with non-communicable diseases

The issues of clinical significance and possibilities of assessing the indicators of variation pulsometry measurement and spectral analysis of a short recording of heart rate variability are highlighted in the article. This is necessary as an objective justification for the subsequent assessment of the functional state of the body and a comprehensive examination of comorbid patients for non-communicable diseases.The aim of the study was to assess the clinical and diagnostic value of a short recording of heart rate variability in comorbid patients with non-communicable diseases in order to increase the effectiveness of measures for their prevention and treatment in Ukraine by improving their diagnosis and prevention through the introduction of modern science-intensive technologies into medical practice.Material and methods. 174 comorbid patients with non-communicable diseases were examined by registering a short record of variability on the hardware-soft-ware complex Poly-Spectrum (Neurosoft, Russia) and the analysis of the results was done. The patients were divided into three groups depending on the degree of comorbidity.Results. Significant differences in spectral analysis and variation pulsometry measurements were established in patients with non-communicable diseases, depending on the degree of comorbidity.Conclusions. The expediency of using the method of short recording of heart rate variability in a comprehensive examination of comorbid patients has been established. The indicator of the total spectral power of the heart rate can be recommended for use as an additional independent predictor of the severity of comorbid pathology and assessment of the functional state.

CARDIOVASCULAR CONTINUUM IN THE RESULTS OF SHORT RECORDING OF HEART RATE VARIABILITY: POSSIBILITIES OF INSTRUMENTAL DIAGNOSTICS

The issues of clinical significance and possibilities of using the assessment of spectralanalysis indicators of a short recording of heart rate variability for assessing thefunctional state of patients in accordance with the stages of the cardiovascularcontinuum in non-communicable diseases are described in the article.The aim of the study – to carry out a comparative assessment of the indicators of ashort recording of heart rate variability in respondents with different stages of thecardiovascular continuum in order to increase the effectiveness of measures for theprevention and treatment of non-communicable diseases in Ukraine by improvingtheir diagnosis and prevention through the introduction of modern science-intensivetechnologies into medical practice.Material and methods. 307 respondents were surveyed using the Poly-Spectrumhardware-software complex (Neurosoft, Russia). All of them underwent registrationand analysis of a short recording of heart rate variability. 200 comorbid patients withnon-communicable diseases were divided into four subgroups depending on the stage ofthe cardiovascular continuum and the degree of comorbidity. 107 functionally healthyindividuals (control group) were divided into two subgroups depending on the level ofsports training.Results. A decrease in the electromagnetic power (total and all spectral components)was found in patients with non-communicable diseases, depending on the stage of thecardiovascular continuum. The results of personalized analysis of spectral parametersin all study groups were presented and their medical-clinical interpretation was written.Conclusion. Non-communicable diseases are accompanied by a gradual decreasein the electromagnetic power (total and all spectral components) of cardiac activityin accordance with an increase in the degree of comorbidity and progression of thecardiovascular continuum. The clinical and diagnostic value of a short recording ofheart rate variability as a method for diagnosing a functional state and the expediencyof its use in a comprehensive examination of patients in a clinic of internal diseaseshave been confirmed.

Heart rate variability—study in futsal athletes

Abstract Background The practice of high perfomance sports leads to alterations of the autonomic nervous system (ANS). The study of heart rate variability (HRV) resorting to the electrocardiogram (ECG) is a practical, efficient and non invasive tool that allows the monitorization of the cardiac-autonomic function in high perfomance athletes, exposing the physiological adaptations to repeated and intense physical exercise. To evaluate the resting heart rate variability of futsal players resorting to the electrocardiogram during the pre-season and competitive season. Methods The sample used in this study was composed of fifteen male futsal athletes, subjected to a resting electrocardiogram in supine position with the duration of 6 minutes, at two different moments. Results From the first to the second record heart rate variability, it was observed a significant decrease in heart rate from 66.53 ± 10.39 bpm to 61.50 ± 11.14 bpm (P < 0.05) and the indexes related to the activity of the parasympathetic nervous system (PNS), RMSSD, pNN50, HFnu did not present statistical significance (P > 0.05) despite the verified increased of absolute values from the first to the second evaluation. Conclusions We were able to observe a decrease in heart rate (HR), as well as, a tendency for elevated parasympathetic indexes and a vagal predominance from the first to the second moment of evaluation. The monitorization of heart rate variability can be useful to identify adaptations to competitive loads and, thus, planning adequate training loads for each athlete, avoiding the occurrence of lesions and fatigue and allowing an improvement in performance.

Heart Rate Variability Guided Exercise Prescription: Effects On Fitness, Body Composition And Cardiovascular Regulation

Heart rate variability (HRV) monitoring can assess individual adaptation to training. Whether high-intensity functional training (HIFT) prescription would benefit from HRV monitoring and modulation is unclear. PURPOSE: To determine effects of HRV-modulated HIFT on fitness, body composition, and HRV changes. METHODS: Healthy adults (N = 55) were randomly assigned to HIFT (n = 29, age = 24.1 ± 4.1 years, 41.4% men) or HIFT-HRV modulated (n = 26, age = 23.7 ± 4.5, 53.8% men) groups. Both groups completed 11-weeks of daily HRV recordings with a validated mobile phone application, 6-weeks of HIFT (5 d·week-1), and pre- and post-test fitness tests [i.e., 1 rep max press, back squat, deadlift (DL); VO2max; work capacity (WC); resting heart rate (RHR); coefficient of variance (CV) in HRV], body composition [i.e., body fat percentage (BF%), lean body mass (LBM), fat mass (FM)], days at high intensity (DHI), HRV compliance]. Meaningful changes in resting HRV were used to modulate (i.e., reduce) participants’ exercise intensity. Linear mixed models were used with the Bonferroni post hoc adjustment. RESULTS: Significant main effects of sex were found for fitness (press: M diff = -22.1 ± 5.14, p < 0.001; DL: M diff = -29.7 ± 14.3, p < 0.05; CV in HRV: M diff = 1.82 ± 0.73, p < 0.05, WC: M diff = -37.9 ± 17.6, p < 0.05); body composition (BF%: M diff = 9.03 ± 4.27, p < 0.05; LBM: M diff = -9.71 ± 2.91, p < 0.05); DHI (M diff = 9.90 ± 1.37, p < 0.05); HRV compliance (M diff = 3.75 ± 0.99, p < 0.001). Significant main effects of time were found for fitness (squat: M diff = -7.98 ± 1.48, p < 0.001; press: M diff = -2.62 ± 0.81, p < 0.05; DL: M diff = -10.4 ± 2.21, p < 0.001; RHR: M diff = 13.0 ± 6.65, p < 0.05; WC: M diff = -16.9 ± 4.38, p < 0.001); and body composition (LBM: M diff = -1.19 ± 0.3, p < 0.001; FM: M diff = 0.62 ± 0.3, p < 0.05). There was a significant sex*time interaction for fitness (DL: M diff = 15.09 ± 4.23, p < 0.001; VO2max: M diff = 2.66 ± 0.98, p < 0.05) as well as a sex*group interaction for DHI (M diff = -3.05 ± 2.73, p < 0.05). CONCLUSION: HRV modulated HIFT produced similar improvements in fitness, body composition and changes in CV for HRV as regular HIFT. HRV modulated training showed similar adaptations with fewer days at high intensity for men. Women sustained more days at high intensity than men. HRV may be an appropriate marker for prescribing exercise intensity during HIFT.

Effects of visual search task on attentional bias and stress response under pressure.

it has always been a problem for athletes that their performance is out of order due to pressure in major competitions. The change of attention pattern and the emergence of stress response (SR) caused by negative affect (NA) are the direct reasons for the greater impact on the performance of athletes. It is a hot topic to explore how to improve attention bias (AB) and SR of athletes in stressful situations. the study aimed to analyze the improvement effect of visual search task (VST) training on AB and SR of athletes under pressure situations. 62 male basketball players with national level 2 or above of Shenyang sports institute were divided into experimental group (EG) and control group (CG). Visual search task training program was used in the EG (happy, sad, disgusted, neutral faces) and sham training program was used in the CG (all faces with neutral expression) for two months. Under the stress situation, attention behavior of all subjects before and after training was tested. Physiological coherence and autonomic balance system were used to record heart rate variability synchronously. Parallel frequency domain analysis was divided into very low frequency band (VLF), low frequency (LF), high frequency (HF) and total spectrum (TP). The normalized treatment obtained indexes such as HFnorm, LFnorm, and LF/HF. The e-prime 2.0 software was adopted to obtain the attention bias score. The Positive and Negative Affect Scale (PANAS) and the self-rating stress scale were adopted for evaluation before and after training. the self-rating pressure in the two groups was lower than that before the training, and the pressure in the experimental group was lower than that in the control group (P < 0.05). After training, the positive emotion of the experimental group was higher than that of the control group, and the EG was lower than that of the CG (P < 0.05). After training, the score of attention bias of happy and neutral faces in the EG was higher than that of theCG, while the score of attention bias of sad and disgusted faces was lower than that of the CG (P < 0.05). After training, LF/HF and LFnorm in the EG were lower than those in the CG, and HFnorm was higher than those in the CG (P < 0.05). the training of visual search task can effectively improve the athletes' PA and AB of positive information, reduce the attention bias of negative information and psychological pressure, and relieve theSR.

One-Minute Deep Breathing Assessment and its Relationship to 24-Hour HRV Measurements

Heart rate variability (HRV), 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. Low age-adjusted HRV has been confirmed as a strong, independent predictor of future health problems in both healthy people and patients with a wide range of diseases that correlate with all-cause mortality. Twenty-four–hour HRV recordings are considered the gold standard and have greater predictive power on health risk than short-term recordings. However, it is not always practical or cost effective to obtain 24-hour HRV recordings, and short-term recordings have been widely used in research and clinical applications for many years. This article will report on the first in a series of research investigations on short-term HRV assessments. The first study examined the correlations between a 10-minute resting state, a 1-minute paced deep breathing protocol, response to handgrip, and 24-hour HRV measures in 28 healthy individuals. Based on the results of the initial study, the primary study examined the correlations between the 1-minute paced deep breathing assessment and 24-hour measures in a general population of 805 individuals. Overall, the findings from the studies suggested that the 1-minute paced deep breathing assessments were highly correlated with 24-hour measures of vagally mediated HRV and very-low-frequency power. The findings from this study suggest that the 1-minute paced deep breathing protocol is an ideal short-term assessment that can be used in a health risk screening context. When low values are observed, it is recommended that a 24-hour assessment be conducted.

Association Between Postoperative Long-Term Heart Rate Variability and Postoperative Delirium in Elderly Patients Undergoing Orthopedic Surgery: A Prospective Cohort Study.

BackgroundPostoperative delirium (POD) is a common complication after orthopedic surgery in elderly patients. The elderly may experience drastic changes in autonomic nervous system (ANS) activity and circadian rhythm disorders after surgery. Therefore, we intend to explore the relationship between postoperative long-term heart rate (HR) variability (HRV), as a measure of ANS activity and circadian rhythm, and occurrence of POD in elderly patients.MethodsThe study population of this cohort was elderly patients over 60 years of age who scheduled for orthopedic surgery under spinal anesthesia. Patients were screened for inclusion and exclusion criteria before surgery. Then, participants were invited to wear a Holter monitor on the first postoperative day to collect 24-h electrocardiographic (ECG) data. Parameters in the time domain [the standard deviation of the normal-to-normal (NN) intervals (SDNN), mean of the standard deviations of all the NN intervals for each 5-min segment of a 24-h HRV recording (SDNNI), and the root mean square of successive differences of the NN intervals (RMSSD)] and frequency domain [heart rate (HR), high frequency (HF), low frequency (LF), very low frequency (VLF), ultra low frequency (ULF), and total power (TP)] were calculated. Assessment of delirium was performed daily up to the seventh postoperative day using the Chinese version of the 3-Min Diagnostic Interview for CAM-defined Delirium (3D-CAM). The relationship between HRV and POD, as well as the association between HRV and duration of POD, was assessed.ResultsOf the 294 cases that finally completed the follow-up, 60 cases developed POD. Among the HRV parameters, SDNNI, VLF, and ULF were related to the occurrence of POD. After adjustment for potential confounders, the correlation between HRV indices and POD disappeared. Through stratified analysis, two significant negative correlations emerged: ULF in young-old participants and SDNNI, VLF, and ULF in male patients.ConclusionThe lower HRV parameters may be related to the occurrence of POD, and this correlation is more significant in young-old and male patients. ANS disorders and rhythm abnormalities reflected by HRV changes may represent a possible mechanism that promotes POD.

Ultra-short heart rate variability reliability for cardiac autonomic tone assessment in mesial temporal lobe epilepsy

Autonomic dysfunction in epilepsy is well-described. Heart rate variability (HRV) is a useful method to evaluate autonomic cardiac tone. Cardiac dysfunction may be involved in sudden unexpected death in epilepsy (SUDEP). HRV is a promising biomarker to enlighten the heart-brain axis role in SUDEP, but the required duration for a proper HRV recording in clinical routine remains unknown. This study aimed to verify the reliability of ultra-short HRV indices to evaluate cardiac autonomic tone in patients with epilepsy (PWE). Thirty-nine patients with mesial temporal lobe epilepsy (MTLE) had electrocardiogram recordings during the first day of video-EEG. Pearson’s correlations were performed to evaluate the association between ultra-short HRV indices (five 1-min and five 30-s epochs) with standard time recording (5-min) and ANOVA compared the differences between mean HRV indices across epochs. Time domain (TD) indices showed higher mean r values when compared to frequency domain (FD) indices in 1-min (TD: r 0.80–0.99, FD: r 0.61–0.95) and 30-s epochs (TD: r 0.69–0.99, only high frequency: mean r values of 0.96). ANOVA evidenced that standard deviation of RR intervals and very low frequency means had at least 3 epochs significantly different for 1-min and 30-s epochs. Root mean square of the successive differences of RR intervals (rMSSD) presented higher Pearson’s coefficient values and lower percentage of variation at 1-min or 30-s epochs in comparison to other HRV indices. In conclusion, rMSSD is the most reliable ultra-short HRV index for cardiac autonomic tone assessment in MTLE. The prognostic value of ultra-short HRV for cardiovascular risk evaluation in epilepsy remains to be determined in future studies.

Autonomic and Perceptual Responses to Induction of a Ketogenic Diet in Free-Living Endurance Athletes: A Randomized, Crossover Trial.

Considerable interindividual heterogeneity has been observed in endurance performance responses following induction of a ketogenic diet (KD). It is plausible that a physiological stress response in the period following the dramatic dietary shift associated with transition to a KD may explain this heterogeneity. In a randomized, crossover study design, 8 trained male runners completed an incremental exercise test and ran to exhaustion at 70%VO2max before and after a 31-day rigorously controlled habitual diet or KD intervention, and recorded heart rate variability (root mean square of the sum of successive differences in R-R intervals [rMSSD]) upon waking each morning along with the recovery-stress questionnaire for athletes each week. Data were analyzed using linear mixed models. A significant reduction in rMSSD was observed in the KD (-9.77 [4.03]ms, P = .02), along with an increase in day-to-day variability in rMSSD (2.1% [1.0%], P = .03). The reduction in rMSSD in the KD for the subgroup of individuals exhibiting impaired exercise capacity following induction of the KD approached significance (Δ -22 [15]ms, P = .06, N = 4); whereas no effect was observed in those who exhibited unchanged exercise capacity (Δ 5 [18]ms, P = .61, N = 4). No main effects were observed for recovery-stress questionnaire for athletes. Our data suggest those working with endurance athletes transitioning onto a KD may consider using noninvasive, inexpensive resting heart rate variability measures to gain individual-level insights into the likely short-term effects on exercise capacity.

Time-dependent effects of inspiratory muscle training and detraining on cardiac autonomic control in older women

Inspiratory muscle training improved maximal inspiratory pressure (MIP) and vagal-mediated heart rate variability (HRV) in older women. However, it is unknown what occurs if the training is discontinued (detraining protocol). The aim of this study was to investigate the IMT and detraining effects on resting HRV in older women. Twelve healthy older women (60-72yrs) enrolled in home-based IMT at 50% MIP (IMT-group) or placebo at 5% MIP (Sham-group) protocol for 4weeks using a mechanical pressure threshold loading device. The participants were not engaged in any other exercise protocol at that time. During IMT and Sham interventions, the inspiratory load was adjusted weekly by the actual MIP and resting heart rate variability (HRV) evaluated. After training cessation (4weeks of detraining), participants returned to the lab for HRV and MIP recordings. Adherence to IMT was superior to 95%. IMT increased MIP (23±8 cmH2O) and vagal-mediated HRV (normalized HF; 37±8%), following by the reduction of sympatho-vagal balance (LF/HF), from the second week to the end of the protocol compared to sham-group. After detraining, IMT-group reduced MIP (-23±8 cmH2O) and vagal-mediated HRV (normalized HF; -38±14%) returning to baseline values. In conclusion, MIP and vagal-HRV improvements induced by IMT were reversed by four weeks of detraining.

Effects of Spinal Cord Stimulation on Heart Rate Variability in Patients With Failed Back Surgery Syndrome: Comparison Between a 2-lead ECG and a Wearable Device

Heart rate variability recordings have the potential to examine the role of the autonomic nervous system. Several wearable devices are nowadays readily available. Up until now, no studies explored whether a wearable device is able to reliably measure a treatment response in chronic pain patients. Therefore, the aim of this study is to evaluate the reliability of a Polar V800 (Polar Electro Oy, Finland) wearable device to accurately measure RR intervals in patients with failed back surgery syndrome (FBSS) during spinal cord stimulation (SCS), as compared with an eMotion 2-lead ECG recording. Twenty-two patients diagnosed with FBSS and treated with SCS participated in this study. HRV was measured with a 2-lead ECG registration tool and a Polar V800 during on and off state of SCS. Intraclass correlation coefficients, correlations, limits of agreement, Cronbach's α, and effect sizes were calculated. Analysis based on the recordings from the ECG and wearable device revealed the same HRV parameters (except for the time-frequency domain) to capture the treatment response of SCS. Parameters that are relevant for measuring the SCS treatment response have strong correlations (r ≥ .82), good ICC values (ICC ≥0.82), acceptable consistency (α ≥ .9), and limited bias. Similar pre- to posttreatment changes were revealed between a wearable device and 2-lead ECG with reliable HRV estimates for parameters that are able to capture the treatment changes. This suggests that a wearable heart rate monitor might be a reliable wearable tool for the detection of pre- to post treatment changes of SCS, in patients with FBSS.

Observations of Autonomic Variability Following Central Neuromodulation for Chronic Neuropathic Pain in Spinal Cord Injury

Spinal cord injury (SCI) persons with chronic neuropathic pain (NP) demonstrate maladaptive autonomic profiles compared to SCI counterparts without NP (SCI - NP) or able-bodied (AB) controls. These aberrations may be secondary to maladaptive neuroplasticity in the shared circuitry of the pain neuromatrix-central autonomic network interface (PNM-CAN). In this study, we explored the proposed PNM-CAN mechanism in SCI + NP and AB cohorts following centrally-directed neuromodulation to assess if the PNM and CAN are capable of being differentially modulated. Central neuromodulation was administered via breathing-controlled electrical stimulation (BreEStim), previously evidenced to operate at the PNM. To quantify CAN activity, conventional heart rate variability (HRV) recordings were used to gather time and frequency domain parameters of autonomic modulation. SCI + NP (n = 10) and AB (n = 13) cohorts received null and active BreEStim randomly in crossover fashion. HRV data were gathered pretest and 30 minutes posttest. Pain modulation was quantified at both time-points by visual analog scale (VAS) for SCI + NP persons and electrical detection and pain threshold levels (EDT, EPT) for AB persons. Following active BreEStim only, SCI + NP persons demonstrated increased parasympathetic tone (increased NN50, p = 0.03, and pNN50, p = 0.02, HRV parameters). This parasympathetic restoration was associated with analgesia (VAS reduction, p < 0.01). Similarly, AB persons demonstrated increased noxious tolerance (increased EPT, p = 0.03, with preserved EDL, p = 0.78) only following active BreEStim. However, this increased pain threshold was not associated with autonomic changes. Central modulation targeting the PNM produced autonomic changes in SCI + NP persons but not AB persons. These findings suggest that AB persons exhibit intact CAN mechanisms capable of compensating for PNM aberrations or simply that SCI + NP persons exhibit altered PNM-CAN machinery altogether. Our collective findings confirm the interconnectedness and maladaptive plasticity of PNM-CAN machinery in SCI + NP persons and suggest that the PNM and CAN circuitry can be differentially modulated.

Evaluation of the clinical effectiveness of the method for determining the personalized correction of the patient’s lifestyle and new promising predictors

Objective — to assess the clinical and diagnostic efficiency of the method for determining the personified correction of the patient’s lifestyle targeted on the increase the effectiveness of measures for the prevention and treatment of non‑communicable diseases in Ukraine.&#x0D; Materials and methods. Method of the direct assessment of the personified correction of the patient’s lifestyle was applied to 247 respondents (60 functionally healthy athletes, 111 functionally healthy non‑athletes, 76 patients with NCDs) in the open, non‑randomized, controlled study using valeological testing, instrumental bioimpedance measurement, and analysis of a short recording of Heart Rate Variability.&#x0D; Results. Cluster differences have been reveled between the groups as regards the formation of a healthy lifestyle; non‑compliance with the principles of healthy lifestyle in the groups of functionally healthy non‑athletes and patients with NCDs, which was confirmed by significant difference in the indicators of body composition (deficiency of muscle mass, impaired fat metabolism), spectral analysis, variational pulsometry is a short recording of heart rate variability.&#x0D; Results. Cluster differences in the formation of the level of a healthy lifestyle, non‑compliance with the principles of healthy lifestyle in the groups of functionally healthy non‑athletes with NCDs were found. This was confirmed by personalized analysis data, significant differences in body composition indicators (lack of muscle mass, impaired fat metabolism), spectral analysis, variational pulsometry, short recording of heart rate variability.&#x0D; Conclusions. The method for determining the personalized correction of the patient’s lifestyle is an effective method for identifying and preventing non‑communicable diseases, in particular at account of the possibility to assess the novel early predictors — the content of muscle tissue and the functional state of the body based on the results of the analysis of a short recording of heart rate variability.&#x0D;

Cardiac-autonomic and hemodynamic responses to a hypertonic, sugar-sweetened sports beverage in physically active men

Hydration practices may confound heart rate variability (HRV) measurements when collected in the pre-training period. We aimed to determine the effects of ingesting a hypertonic, sugar-sweetened sports beverage on HRV and hemodynamic parameters in physically active young men. Fifteen subjects consumed 591mL of Gatorade (6% carbohydrate, ∼330 mOsmol/kg), 591mL water, or 10mL water (control) in random order on separate days following overnight fasting. HRV and hemodynamics were evaluated in 5-min windows immediately before (T1) and 5-10min (T2), 25-30min (T3), 40-45min (T4), and 55-60min (T5) post-drinking. Root-mean square of successive differences and the standard deviation of normal RR intervals increased post-water intake at all time-points relative to T1 (P< 0.05). No increases were observed post-Gatorade intake, though small effect sizes were noted at T2 and T3 (P> 0.05, ES = 0.27-0.32). Systemic vascular resistance increased at T2 post-Gatorade intake and at T2 and T3 post-water intake (P< 0.05). No interactions were observed for blood pressure measures, stroke volume, or cardiac output. Gatorade does not evoke cardiovascular adjustments to the same magnitude as water. Practitioners should wait at least 45min to record HRV post-Gatorade intake and >60min post-water intake. Novelty: Equal volumes of cold water and Gatorade produce inequivalent cardiac-autonomic and hemodynamic responses. HRV responses of greater amplitude and duration were observed following intake of water versus Gatorade. Failure to account for recent fluid intake may result in misinterpretation of autonomic status.

“THE HEART KNOWS ALL ABOUT US”: AN ASSESSMENT OF THE FUNCTIONAL STATE OF PATIENTS BY THE INDICATORS OF A SHORT RECORDING OF THE HEART RATE VARIABILITY

This article highlights the issues of using a hardware technique for assessing the functional state of patients by indicators of a short recording of heart rate variability. The aim of the study is to assess the clinical and diagnostic capabilities of a short recording of heart rate variability in displaying systemic informational energy processes of the human body to increase the effectiveness of measures for the prevention and treatment of non-communicable diseases in Ukraine by introducing the latest science-based technologies into medical practice. An open-label, nonrandomized controlled trial was performed. We studied the wave characteristics of the heart rate in functionally healthy individuals (group 1, n=104) and patients with coronary heart disease including exertional angina, myocardial infarction (in the subacute period) and comorbid pathology (group 2, n=66) by the method of short recording of heart rate variability using spectral analysis and variational pulsometry. The study has demonstrated coronary heart disease is accompanied by a decrease in the overall activity of regulatory systems, inhibition of the energy level of the heart (TP=931.8±710.4 at a rate of 3466±1018 ms²), a low level of hormonal modulation of regulatory mechanisms (VLF=527.3±502.1 ms², which is &lt;700 ms²), depletion of energy resources, a low level of recoverable (HF=205.7±261.8 ms², which is &lt;300 ms²) and mobilization (LF=198.9±191.7 ms², which is &lt;300 ms2) potentials, an imbalance of the mechanisms of neuro-humoral regulation of cardiac activity, a decrease in the resources of cardiac activity VLF=56% when normal values are within 30-50%; VLF&gt;HF+LF), in a state of pronounced distress (SI=256.7±264.7; SI=325.2±297.7; PAPR=71.76±30.3). Using the method of short recording of heart rate variability can allow doctors to determine the current state of physiological circulatory mechanisms, adaptive responses, diagnose maladaptive disorders, stress, monitor the effectiveness of prevention of noncommunicable diseases in respondents.

Monitoring the Heart Rate Variability Responses to Training Loads in Competitive Swimmers Using a Smartphone Application and the Banister Impulse-Response Model.

First, to examine whether heart rate variability (HRV) responses can be modeled effectively via the Banister impulse-response model when the session rating of perceived exertion (sRPE) alone, and in combination with subjective well-being measures, are utilized. Second, to describe seasonal HRV responses and their associations with changes in critical speed (CS) in competitive swimmers. A total of 10 highly trained swimmers collected daily 1-minute HRV recordings, sRPE training load, and subjective well-being scores via a novel smartphone application for 15 weeks. The impulse-response model was used to describe chronic root mean square of the successive differences (rMSSD) responses to training, with sRPE and subjective well-being measures used as systems inputs. Changes in CS were obtained from a 3-minute all-out test completed in weeks 1 and 14. The level of agreement between predicted and actual HRV data was R2 = .66 (.25) when sRPE alone was used. Model fits improved in the range of 4% to 21% when different subjective well-being measures were combined with sRPE, representing trivial-to-moderate improvements. There were no significant differences in weekly group averages of log-transformed (Ln) rMSSD (P = .34) or HRV coefficient of variation of Ln rMSSD (P = .12); however, small-to-large changes (d = 0.21-1.46) were observed in these parameters throughout the season. Large correlations were observed between seasonal changes in HRV measures and CS (changes in averages of Ln rMSSD: r = .51, P = .13; changes in coefficient of variation of Ln rMSSD: r = -.68, P = .03). The impulse-response model and data collected via a novel smartphone application can be used to model HRV responses to swimming training and nontraining-related stressors. Large relationships between seasonal changes in measured HRV parameters and CS provide further evidence for incorporating a HRV-guided training approach.

Agreement of Ultra-Short-Term Heart Rate Variability Recordings During Overseas Training Camps in Under-20 National Futsal Players.

Background: Monitoring the daily change in resting heart rate variability (HRV) can provide information regarding training adaptation and recovery status of the autonomic nervous system (ANS) during training camps. However, it remains unclear whether postural stabilization is essential for valid and reliable ultra-short-term (HRVUST) recordings in short-term overseas training camps.Design: Observational and longitudinal study.Purpose: This study aimed to investigate ultra-short-term heart rate variability recordings under stabilization or post-stabilization periods in four overseas training camps.Participant: Twenty-seven U-20 male national team futsal players voluntarily participated in this study.Method: Resting HRV was evaluated for 10 min during the early morning of each training camp. The natural logarithm of the root mean square of successive normal-to-normal interval differences (LnRMSSD) was used for comparisons. Time segments of HRV were divided into two periods with three measures within each: (1) the first 30-s (1st_30 s LnRMSSD), the first 60-s (1st_60 s LnRMSSD), and the 5-min standard (1st_5 min LnRMSSD) during stabilization; (2) the first 30-s (2nd_30 s LnRMSSD), the first 60-s (2nd_60 s LnRMSSD), and the 5-min standard (2nd_5 min LnRMSSD) after stabilization.Result: The results demonstrated trivial to small ES (−0.03; 0.46), very large to nearly perfect ICC (0.76; 0.98), and narrow range of SEM (0.06; 0.31) when all time segments of HRVUST were compared to the 1st_5 min and 2nd_5 min HRV. Furthermore, the magnitude of the correlation coefficients ranged from very high to nearly perfect for all the time segments (r = 0.83; 0.97). The HRVUST posted excellent agreement in all time segments (bias = −0.05; 0.12) with/without postural stabilization. Trivial to small levels of effect size in all time segments of LnRMSSDmean (0.02; 0.41 ES) and LnRMSSDcv (−0.49; −0.02 ES) across overseas training camps was identified.Conclusion: The first 30 or 60-s LnRMSSD recordings can be used to evaluate daily cardiac-autonomic function during overseas training camps in futsal players. The process for stabilization seems to be unnecessary for measuring the morning resting LnRMSSD in overseas training camps among young adult futsal players.

Heart Rate Variability Modulates Interoceptive Accuracy

Our emotional experiences depend on our interoceptive ability to perceive and interpret changes in our autonomous nervous system. An inaccurate perception and interpretation of autonomic changes impairs our ability to understand and regulate our emotional reactions. Impairments in emotion understanding and emotion regulation increase our risk for mental disorders, indicating that interoceptive deficits play an important role in the etiology and pathogenesis of mental disorders. We, thus, need measures to identify those of us whose interoceptive deficits impair their emotion understanding and emotion regulation. Here, we used cardiac measures to investigate how our ability to engage prefrontal and (para-)limbic brain region regions affects our ability to perceive and interpret cardiac changes. We administered a heartbeat detection task to a sample of healthy individuals (n = 113) whose prefrontal-(para-) limbic engagement had been determined on basis of a heart rate variability recording. We found a positive association between heartbeat detection and heart rate variability, implying that individuals with higher heart rate variability were more accurate in heartbeat detection than individuals with lower heart rate variability. These findings suggest that our interoceptive accuracy depends on our prefrontal-(para-)limbic engagement during the perception and interpretation of cardiac changes. Our findings also show that cardiac measures may be useful to investigate the association between interoceptive accuracy and prefrontal-(para-)limbic engagement in a time- and cost-efficient manner.

The Interplay Between Chamber Musicians During Two Public Performances of the Same Piece: A Novel Methodology Using the Concept of "Flow".

The purpose of the study is to explore a new research methodology that will improve our understanding of “flow” through indicators of physiological and qualitative state. We examine indicators of “flow” experienced by musicians of a youth string quartet, two women (25, 29) and two men (23, 24). Electrocardiogram (ECG) equipment was used to record heart rate variability (HRV) data throughout the four movements in one and the same quartet performed during two concerts. Individual physiological indicators of flow were supplemented by assessments of group “state flow” (means from standardized questionnaires) and a group interview in which the musicians provided qualitative data. A matrix was constructed for the characterization of different kinds of demands in the written music in each one of the four movements for each one of the musicians. HRV derived from ECG data showed non-significant trends for group state flow across the eight musical episodes. Individual-level analysis showed that compared to the other players the first violin player had the highest mean heart rate and the lowest increase in high frequency (HF) power in HRV during this particular movement, particularly during the second concert. The qualitative data illustrated how an interplay of synchronized social interactions between this player and their colleagues during the musical performance was associated with a feeling of group state flow and served to support the first violinist. The case illustrates that the proposed mixed methodology drawing on physiological and qualitative data, has the potential to provide meaningful information about experiences of a flow state, both at individual and group levels. Applications in future research are possible.

Effect of head down tilt on heart rate variability.

Context:Sirshasan is supposed to increase blood flow to the brain and considered to be beneficial for intellectual function, however mastering these techniques may be difficult.Aims:To see the effect of headstand using a tilt table on heart rate variability (HRV).Settings and Design:A cross-sectional study that was done on 26 healthy volunteers.Methods and Material:HRV was assessed in the supine position and 30° head tilt position for 5 min. HRV recording was done on the power lab (AD Instruments P Ltd, Castle Hill Australia). The tilt table used was Medica Podium, New Delhi, HLT-200.Statistical analysis used:Paired t-test.Results:All the HRV parameters showed non-significant change except low-frequency parameters which showed significant change during head tilt.Conclusions:Headstand to a 30° using tilt table cause a decrease in the autonomic activity which is mainly because of decrease in sympathetic activity.