Heart Rate Variability Research Articles

Effect of Yoga Therapy on Hypothyroidism: A Systematic Review

Background Hypothyroidism (HT) is the most prevalent endocrine disorder, affecting approximately one in 10 out of 35 adults, with a higher prevalence in females and the elderly. Purpose This systematic review (SR) aimed to discuss the effects of yoga on markers and comorbid conditions of HT. Methods The SR was registered with the PROSPERO (PROSPERO 2022 CRD42022312990). Google Scholar, PubMed, Cochrane, and EMBASE were searched for the relevant English language interventional studies published from 31 December 1947 to 31 December 2023 by using the keywords ‘meditation OR breath regulation OR yoga OR yoga nidra AND hypothyroidism OR hypothyreosis OR underactive thyroid OR low thyroid’. Of the 4078 screened studies, eight eligible studies (three RCTs, two pilot studies, two pre-post trials, and one case study) with 421 HT patients (392 females and 29 males) and three to six-month yoga interventions were included. Two independent review authors extracted study characteristics and synthesised them descriptively. RCTs and NRSIs were assessed for risk-of-bias (RoB) using Cochrane tools RoB2 and ROBINS-1. Results The findings suggest that yoga effectively improves the thyroid profile, lipid profile, heart rate variability, pulmonary functions, anxiety, depression, and quality of life among HT patients. Conclusion Yoga may be an inexpensive add-on preventive and therapeutic option for HT. The clinical and methodological heterogeneity among the studies did not allow for meta-analysis (MA). Well-designed MAs are warranted by including rigorous RCTs to draw valid conclusions and defined mechanisms regarding the efficacy of yoga practices/interventions on HT.

Safety in the application of high-velocity low-amplitude technique in upper cervical in elderly: Preliminary study

Background: The literature is still controversial regarding the safety of applying high-velocity, low-amplitude (HVLA) techniques to the upper cervical spine, as well as the effects on heart rate variability (HRV) in the elderly. To date, there are no studies reporting the safety of applying these techniques to elderly. Objective: To verify the safety and immediate effects on HRV after applying an HVLA technique to elderly, for the purpose of conducting a future clinical trial. Materials and Methods: This is a preliminary, randomized, crossover study. Six physically active elderly individuals without cardiovascular disease were recruited. The subjects underwent two interventions, with a seven-day interval between them: intervention one consisted of an HVLA technique to the upper cervical spine, while intervention two was a simulated (sham) technique. Data on self-reported symptoms after applying the techniques were collected, in addition to HRV, to assess autonomic function. Results: There were no records of immediate adverse effects after applying the intervention techniques. However, a significant increase in the root means square difference between adjacent normal RR intervals over a time interval (RMSSD) and in the instantaneous beat-to-beat heart rate recording (SD1) was observed in the HVLA group when compared to the sham group. Conclusion: The application of the HVLA technique in the upper cervical spine did not produce self-reported adverse effects in elderly. The HVLA technique increased the activity of the parasympathetic nervous system, producing adjustments in HRV, thus indicating that there may be a significant parasympathetic stimulation in elderly.

Heart Rate Variability and Interoception in Periodic Limb Movements in Sleep: Interference with Psychiatric Disorders?

Periodic limb movements in sleep (PLMS) are a prevalent disorder characterized by rhythmic, involuntary movements of the lower limbs, such as dorsiflexion of the ankle and extension of the big toe, occurring in periodic intervals during sleep. These movements are often linked to disrupted autonomic nervous system (ANS) activity and altered interoception. Interoception involves perceiving internal bodily states, like heartbeat, breathing, hunger, and temperature, and plays a crucial role in maintaining homeostasis and the mind-body connection. This review explores the complex relationships between PLMS, heart rate variability (HRV), ANS dysregulation, and their impact on psychiatric disorders. By synthesizing the existing literature, it provides insights into how ANS dysregulation and altered interoceptive processes, alongside PLMS, contribute to psychiatric conditions. The review highlights the potential for integrated diagnostic and therapeutic approaches and presents a cause-and-effect model illustrating the mutual influence of psychiatric disorders, ANS dysregulation, PLMS, and interoception.

Self-Immersed Expressive Writing Increases LF/HF Ratio and Decreases Expressive Suppression

Abstract: Expressive writing helps the disclosure of an emotionally charged event, in a safe and nonthreatening environment, while focusing on the feelings and emotions associated with a traumatic experience. Studies have proposed that expressive writing improves both mental and physical health, and that writing perspective might influence expressive writing outcomes. However, no studies have compared both emotion regulation outcomes and Heart-Rate Variability between self-immersed (I) and self-distancing expressive writing (She/He). Two hundred and one college students at a university were randomly assigned to either an expressive group, writing about their most upsetting life experience (using either a self-immersed or distanced perspective), or a control group (using either a self-immersed or distanced perspective), writing about their daily routine. Positive and negative affect, emotion regulation, anxiety and alexithymia were measured before and after writing. Heart-rate variability was recorded during the experiment to examine the effects of the writing exercise on the autonomous nervous system. We found that suppression decreased at follow-up (η2p = .023) and LF/HF ratio increased after writing (η2 p = .031) in the self-immersed expressive group, in comparison to the self-immersed control group. These are promising results as they suggest that self-immersed expressive writing might be used to foster emotion regulation.

Efficacy and Safety of Ciprofol Versus Propofol as Anesthetic for Patients Undergoing Painless Colonoscopy.

Ciprofol is a novel propofol analogue with a characteristic of hemodynamic stability. At present, there is a lack of research comparing the hemodynamic stability of ciprofol and propofol during painless colonoscopy. In this study, we aim to test the hypothesis that ciprofol is superior to propofol in terms of hemodynamic stability for sedation anesthesia in patients undergoing colonoscopy. A total of 222 patients were randomized into two groups. Patients in group P (n=112) and group C (n=110) received propofol and ciprofol sedation, respectively. Noninvasive blood pressure were monitored starting from induction (T0) to the end of the procedure, at 2-min intervals (T1 to T10). Heart rate variability (HRV), pain injection, Modified Observer's Assessment of Alertness and Sedation(MOAA/S) score, body movement, doses of norepinephrine, modified Aldrete score, drug-related adverse reactions, and patient satisfaction and endoscopist satisfaction were recorded. In group C, fewer patients experienced a decrease in blood pressure with a higher HRV after induction sedation, the incidence of pain injection was reduced, the amount of norepinephrine dose was decreased, patient satisfaction was increased compared with group P (all P<0.05). There were no significant differences in induction time, modified Aldrete score, alertness time, drug-related adverse reactions, and endoscopist satisfaction. Our study indicated intravenous induction with ciprofol was superior, with regard to hemodynamic stability and reduced injection pain, than induction with propofol for anesthesia in patients undergoing painless colonoscopy. Chinese Clinical Trial Registry (ChiCTR2200061814).

Acute right-sided transcutaneous vagus nerve stimulation improves cardio-vagal baroreflex gain in patients with chronic heart failure.

The aim of this paper is to investigate the acute effects of short-term transcutaneous vagus nerve stimulation (tVNS) on cardio-vagal baroreflex gain and heart rate variability in patients with chronic heart failure (CHF). A total of 16 adults with CHF and left ventricular ejection fraction (LVEF) < 50% in sinus rhythm were enrolled (65 ± 8years, 63% men, LVEF 40 ± 5%, 88% on beta-blockers, 50% on quadruple CHF therapy). Over a single experimental session, after a 10-min baseline recording, each patient underwent two trials of 10-min tVNS (Parasym Device, 200µs, 30Hz, 1mA below discomfort threshold) at either the right or left tragus in a randomized order, separated by a 10-min recovery. Compared with baseline, tVNS did not affect heart rate, blood pressure, and respiratory rate (p > 0.05), and no patients complained of discomfort or any adverse effect. Right-sided tVNS was associated with a significant increase in cardio-vagal baroreflex gain (from 5.6 ± 3.1 to 7.5 ± 3.8ms/mmHg, ∆ 1.9 ± 1.6ms/mmHg, p < 0.001), while no change was observed with left-sided tVNS (∆ 0.5 ± 2.0ms/mmHg, p = 0.914). These findings were independent of stimulation-side order (excluding any carry-over effect) and consistent across sex, LVEF category, and HF etiology subgroups (p-value for interaction > 0.05). Acute right-sided tVNS increases cardio-vagal baroreflex gain in patients with CHF and LVEF < 50%, with no tolerability concerns.

Linking brain-heart interactions to emotional arousal in immersive virtual reality.

The subjective experience of emotions is linked to the contextualized perception and appraisal of changes in bodily (e.g., heart) activity. Increased emotional arousal has been related to attenuated high-frequency heart rate variability (HF-HRV), lower EEG parieto-occipital alpha power, and higher heartbeat-evoked potential (HEP) amplitudes. We studied emotional arousal-related brain-heart interactions using immersive virtual reality (VR) for naturalistic yet controlled emotion induction. Twenty-nine healthy adults (13 women, age: 26 ± 3) completed a VR experience that included rollercoasters while EEG and ECG were recorded. Continuous emotional arousal ratings were collected during a video replay immediately after. We analyzed emotional arousal-related changes in HF-HRV as well as in BHIs using HEPs. Additionally, we used the oscillatory information in the ECG and the EEG to model the directional information flows between the brain and heart activity. We found that higher emotional arousal was associated with lower HEP amplitudes in a left fronto-central electrode cluster. While parasympathetic modulation of the heart (HF-HRV) and parieto-occipital EEG alpha power were reduced during higher emotional arousal, there was no evidence for the hypothesized emotional arousal-related changes in bidirectional information flow between them. Whole-brain exploratory analyses in additional EEG (delta, theta, alpha, beta and gamma) and HRV (low-frequency, LF, and HF) frequency bands revealed a temporo-occipital cluster, in which higher emotional arousal was linked to decreased brain-to-heart (i.e., gamma→HF-HRV) and increased heart-to-brain (i.e., LF-HRV → gamma) information flow. Our results confirm previous findings from less naturalistic experiments and suggest a link between emotional arousal and brain-heart interactions in temporo-occipital gamma power.

Effects of long-term transcutaneous auricular vagus nerve stimulation on circadian vagal activity in people with Prader-Willi Syndrome: A case-series

BackgroundPrader-Willi Syndrome (PWS) is a genetic neurodevelopmental disorder marked by disruptions in circadian rhythms and autonomic nervous system (ANS) activity, hyperphagia, and episodes of emotional outbursts. Previous trials suggest that both invasive and non-invasive vagus nerve stimulation (VNS) can reduce emotional outbursts in PWS, potentially through its effects on vagal activity. AimThis case series investigated the effects of transcutaneous auricular VNS (taVNS) on cardiac markers of circadian vagal activity, specifically heart rate variability (HRV) and heart rate (HR), and their potential links to improvements in emotional outbursts. MethodsFive individuals with PWS (mean age: 26.9 years; 3 males, 2 females) received four hours of daily taVNS for 12 months, followed by one month of two-hour daily sessions. Outcome measures included daily recording of emotional outbursts and every three months 24-h HRV and HR recordings. Mixed cosinor models were applied to analyze changes in circadian rhythms of HRV and HR. A linear mixed model was used to assess the predictive value of cardiac vagal activity on emotional outbursts. ResultsCircadian amplitudes of HRV and HR were significantly higher at the end of the treatment compared to baseline (all p’s < .01). There was a significant increase in the rhythm-adjusted mean of HRV (p < .01), while the rhythm-adjusted HR mean significantly decreased, both indicating increased cardiac vagal activity. Higher rhythm-adjusted mean HRV predicted a lower number of emotional outbursts. ConclusionThe results suggest that taVNS may be effective by targeting ANS activity in individuals with PWS, contributing to improvements in behavioral regulation.

Heart Rate Variability During Rapid Eye Movement Sleep is Associated with Reduced Negative Memory Bias.

Emotional memories change over time, but the mechanisms supporting this change are not well understood. Sleep has been identified as one mechanism that supports memory consolidation, with sleep selectively benefitting negative emotional consolidation at the expense of neutral memories, with specific oscillatory events linked to this process. In contrast, the consolidation of neutral and positive memories, compared to negative memories, has been associated with increased vagally-mediated vagal heart rate variability (HRV) during wakefulness. However, how HRV during sleep contributes to emotional memory consolidation remains unexplored. We investigated how sleep oscillations and vagal contributions during sleep contribute to the consolidation of neutral and negative memories. Using a double-blind, placebo-controlled, within-subject, cross-over design, we examined the impact of pharmacological vagal suppression using zolpidem on overnight emotional memory consolidation. Thirty-two participants encoded neutral and negative pictures in the morning, followed by picture recognition tests before and after a night of sleep. Zolpidem or placebo was administered in the evening before overnight sleep, and participants were monitored with electroencephalography and electrocardiography. In the placebo condition, greater overnight improvement for neutral pictures was associated with higher vagal HRV in both Non-Rapid Eye Movement Slow Wave Sleep (NREM SWS) and REM. Additionally, the emotional memory tradeoff (i.e., difference between consolidation of neutral versus negative memories) was associated with higher vagal HRV during REM, but in this case, neutral memories were remembered better than negative memories, indicating a potential role for REM vagal HRV in promoting a positive memory bias overnight. Zolpidem, on the other hand, reduced vagal HRV during SWS, increased NREM sigma power, and eliminated the positive memory bias. Lastly, we used a stepwise linear mixed effects regression to determine how NREM sigma power and vagal HRV during REM independently explained the variance in the emotional memory tradeoff effect. We found that the addition of vagal HRV in combination with sleep significantly improved the model's fit. Overall, our results suggest that sleep brain oscillations and vagal signals synergistically interact in the overnight consolidation of emotional memories, with REM vagal HRV critically contributing to the positive memory bias.

Cardiovascular autonomic function in middle-aged people with long-term cervical and upper thoracic spinal cord injuries

Objectives To examine cardiovascular autonomic function in middle-aged people with long-term cervical and upper thoracic spinal cord injury (SCI) compared with the general population, and explore if the neurological level of injury (NLI) is related to cardiovascular autonomic function. Design Population-based cross-sectional study with matched controls. Setting Outpatient SCI unit in Southern Sweden. Participants Twenty-five individuals (20% women, mean age 58 years and mean time since injury 28 years, NLI C2-T6, American Spinal Injury Association Impairment Scale A-C) from the Swedish SPinal Cord Injury Study on Cardiopulmonary and Autonomic Impairment (SPICA). Matched controls were obtained from the population-based Swedish CArdioPulmonary bioImage Study (SCAPIS) at a ratio of 5:1. Interventions Not applicable. Outcome measures 24 h electrocardiography and deep breathing tests. 24 h ambulatory blood pressure (BP) monitoring and orthostatic BP tests. Results In individuals with SCI compared with controls, heart rate variability (24h mean SD of the normal-to-normal interval 112 ms vs 145 ms, P < 0.001) and diastolic orthostatic BP increase (2.0 and 9.4 mmHg, P < 0.001), were significantly lower, whereas BP variability was significantly higher (24h mean systolic SDBP 17.8 mmHg vs 15.7 mmHg, P = 0.029). Circadian patterns of heart rate variability and BP (lack of nocturnal dip) were significantly different among the individuals with SCI than controls. Higher NLI was significantly (P < 0.05) correlated with impairments to various cardiovascular autonomic function variables. Conclusions This exploratory study indicates that cardiovascular autonomic function is impaired in middle-aged people with long-term cervical and upper thoracic SCI compared with the general non-SCI population, and more pronounced with a higher NLI. Future research is needed to understand the pathophysiological mechanisms underlying these impairments, and the prognostic significance for individuals with SCI. Trial registration ClinicalTrials.gov identifier: NCT03515122.

Age-Related Changes in Heart Rate Variability from the Neonatal Period to Adulthood.

The aim of the study was to reveal the patterns of the age-related dynamics of the frequency-dependent regulation of heart rate variability (HRV) based on the analysis of Holter ECG recordings from healthy subjects of four age groups: neonates, one-year-old infants, adolescents, and adults. A wide spectral composition of HRV is shown, consisting of nine Hilbert-Huang modes in the frequency range from 0.0001 to 2 Hz. A decrease in the central frequencies of all modes is shown in the postnatal period with a plateau in adolescence. A rapid progression of systemic humoral regulation of HRV, characterized by a consolidated increase in the amplitudes of the corresponding modes with a plateau in adolescence, is demonstrated. The dome-shaped character of age-related changes in amplitude of modes associated with autonomic control with a maximum in adolescence is shown. The results obtained quantitatively demonstrate age-related consolidated changes in HRV parameters from neonates to adulthood.

Acute and subacute psychophysiological responses in body weight HIIT sessions: a systematic review

Objective: This review synthesized evidence on the use of body weight exercises through high-intensity interval training (HIIT-BW). Methods: The research was performed in the Science Direct, Embase, MEDLINE, PEDro, SciELO, CINAHL, and LILACS databases from 2013 to 2023. Descriptors such as: high-intensity whole-body, high-intensity functional training, whole-body, whole-body training, whole-body calisthenics, high-intensity calisthenic training, and HIIT bodywork were used. In addition, original articles in English and Portuguese that addressed body weight HIIT were included. The final analysis consisted of 12 articles. Results: HIIT-BW protocols presented varied methodological characteristics: number of series ranged from 4 to 20; stimulus time ranged from 5 to 30 seconds with all-out intensity; and the passive interval ranged from 10 to 35 seconds between the series in 11 studies. The acute responses resulted in psychophysiological changes, increased lactate, Rated Perceived Exertion (RPE), heart rate (HR), fatigue, sweating rate, body size perception, training load, maximum oxygen volume (VO2max), caloric expenditure, perception of recovery, feeling of anger, mood disorder, intention of physical activity and reduction in the perception of pleasure, variability in HR, number of movements in complex exercises, and vigor. When compared with moderate continuous exercise and other high-intensity interval training protocols, HIIT-BW presented similar responses, however the use of preferred songs in the session provided an increase in the number of movements and perception of pleasure when compared with sessions that used non-preferred music and without music. Conclusion: In conclusion, based on data from studies found in the literature, HIIT-BW sessions promote increased feelings of fatigue, anger, mood disorder, RPE, HR, lactate, sweating rate, body size perception, caloric expenditure, and VO2. The results found helped to project indicators of long-term physical fitness and to plan sessions aimed at improving the lifestyle of its practitioners.

Personalized Intervention Strategy Based on a Risk Score Generated From Subcutaneous Insertable Cardiac Monitor: Results From Phase 1 of ALLEVIATE-HF.

Diagnostic variables from insertable cardiac monitors may be useful in identifying patients at increased risk of heart failure (HF) events. High-risk alerts must be coupled with interventions to improve outcomes. We aim to assess the safety of a predefined protocolized intervention pathway activated by insertable cardiac monitor high-risk alerts. ALLEVIATE-HF (Algorithm Using LINQ Sensors for Evaluation and Treatment of Heart Failure) Phase 1 was a randomized interventional study enrolling patients with New York Heart Association class II/III and a recent HF event. A HF risk score based on insertable cardiac monitor diagnostics, including impedance, respiration rate, atrial fibrillation burden, heart rate during atrial fibrillation, heart rate variability, and activity duration, was calculated. A protocolized intervention pathway was activated when high-risk scores were detected that involved physician-prescribed nurse-implemented uptitration of diuretic for 4 days, unless safety rule-out conditions were met. Interventions could be repeated if high-risk scores persisted and did not require worsening symptoms. In total, 59 patients were randomized (mean age 68.2±11.8 years; 59.3% male); 67.8% with ejection fraction ≥50%. The mean follow-up was 11.8±8.1 months. Overall, 146 high-risk scores were recorded in 33 patients and 118 interventions occurred in 75 (51.4%) high-risk alerts that did not meet safety rule-out criteria. There were no serious adverse events and 13 adverse events related to interventions. In patients with symptoms at intervention initiation, symptoms resolved in 37 interventions (80%) and worsened in 8 (17%). In asymptomatic patients, symptoms developed in 3 interventions (7%). A personalized medication intervention based on insertable cardiac monitor risk score can be safely instituted in patients with HF, irrespective of symptoms. URL: https://www.clinicaltrials.gov; Unique Identifier: NCT04452149.

Examining the relationship between subjective exercise tolerance and psychophysiological reactivity during physical stress.

It has been hypothesized that one's ability to control impulses aids in sustaining effort despite experiencing painful physical sensations. Physical exercise has been used extensively as an intervention to strengthen the inhibitory control system and protect an individual's cognitive plan of action. It is unclear, however, whether the high levels of exercise tolerance could facilitate inhibitory control under varied stressors. The present study explored the relationship between subjective exercise tolerance and psychophysiological characteristics that indicate reactivity capacity when exposed to the cold pressor test. Thirty-six participants were divided into two groups based on their subjective exercise tolerance profiles. During the test, participants' psychophysiological reactivity was monitored via heart rate variability. Participants were also required to answer questions about their perceptual and affective states at the beginning and immediately after the stress test. The study revealed insights into dominance perception and emotional states among individuals with varying subjective exercise tolerance levels. High-tolerant individuals endured physical discomfort longer (~50 s) and exhibited higher perceived dominance at the outset of the test when compared to their low-tolerant counterparts. Despite differences in task performance, both groups experienced more positive affective states post-task, potentially as a result of a heightened sense of self-accomplishment. Notably, both groups showed similar levels of psychophysiological reactivity, suggesting a protective effect of physical tolerance on ensuing biological responses. Overall, this study sheds light on the complex relationship between exercise tolerance, dominance perception, and psychophysiological reactivity during physically demanding tasks, enriching our understanding of how developing physical tolerance may impact inhibitory control under stress.

An intensive eye-tracking intervention in children with dyskinetic cerebral palsy: a multiple case study

This study aimed to explore the effects of a four-week intensive eye-tracking intervention on children with dyskinetic cerebral palsy (DCP), focusing on goal attainment, communication competencies, stress levels, subjective workload, and caregivers’ perception of psychosocial impact. A multiple case study design with non-concurrent, staggered multiple baselines was employed, involving three children aged 7, 12, and 13 years. The study included a randomized baseline period of two or three weeks, an intensive eye-tracking intervention, and a six-month follow-up. Two individual eye-tracking goals were identified and assessed using the Goal Attainment Scale, while communication competencies were evaluated with the Augmentative and Alternative Communication Profile: A Continuum of Learning. Stress levels were monitored through Heart Rate Variability measured by the Bittium Faros 360° ECG Holter during eye-tracking tasks. Subjective workload and psychosocial impact were assessed using pictograms and the Psychosocial Impact of Assistive Devices Scale, respectively. Descriptive statistics were applied for analysis. All participants attained and retained their eye-tracking goals, regardless of their initial functional profiles or prior experience with eye-tracking technology. Post-intervention improvements in communication competencies were maintained at the six-month follow-up. Variations in stress levels, subjective workload, and psychosocial impact were observed among participants across different phases of the study, aiding the interpretation of the results. The study concludes that a structured, tailored, four-week intensive eye-tracking intervention can yield successful results in children with DCP, irrespective of their baseline communication abilities or functional profile. Recommendations for future research, including more robust methodologies and reliable computerized tests, are provided.

Multimodal physiological correlates of dyspnea ratings during breath-holding in healthy humans.

Dyspnea is associated with fear and intense suffering and is often assessed using visual analog scales (VAS) or numerical rating scales (NRS). However, the physiological correlates of such ratings are not well known. Using the voluntary breath-holding model of induced dyspnea, we studied healthy volunteers to investigate the temporal relationship between dyspnea, the neural drive to breathe assessed in terms of involuntary thoracoabdominal movements (ITMs) and neurovegetative responses. Twenty-three participants (10 men; median [interquartile range] age 21 [20-21]) performed three consecutive breath-holds with the continuous assessment of dyspnea (urge-to-breathe) using a 10cm VAS, thoracic and abdominal circumferences measured with piezoelectric belt-mounted transducers, heart rate and heart rate variability (HRV), and galvanic skin response (GSR). Urge-to-breathe VAS at the onset of ITMs (gasping point) was identified visually or algorithmically. Urge-to-breathe VAS at the end of the breath-hold was 9.7 [8.6-10] cm. Total breath-hold duration was 93 [69-130]s. Urge-to-breathe VAS, ITM, heart rate, HRV, and GSR significantly increased during breath-hold. Urge-to-breathe VAS correlated with the magnitude of the thoracic and abdominal movements (rho = 0.51 and rho = 0.59, respectively, p < 0.001). The urge-to-breathe ratings corresponding with ITM onset were 3.0 [2.0-4.7] cm and 3.0 [1.0-4.0] cm for visual and algorithmic detection, respectively (p = 0.782). An urge-to-breathe VAS of 3cm (30% of full scale on a 10cm VAS) corresponds to a physiological turning point during the physiological response to voluntary breath-holding in healthy humans.

Measuring psychological immersion through cardiovascular response measures in subtitled films

Abstract This paper presents a conceptual replication of Kruger et al.’s (2017a) study, investigating the utility of heart rate (HR) and heart rate variability (HRV) indicators as objective measurements of psychological immersion in subtitled audiovisual products. The study employed a quasi-experimental design in ten participants viewing video clips with and without subtitles, while their physiological responses were monitored. Results suggest lower arousal levels in both conditions compared to baseline, with statistically significant differences observed in mean HR, mean RR, and RMSSD for the subtitles condition. While most inferential tests did not yield significant outcomes, descriptive trends indicate decreased arousal relative to the baseline. They also show increased arousal throughout the clip for most indicators and opposing trends for Mean HR, RMSSD and LF/HF between the two conditions. Methodological suggestions include using multiple data points for HR and HRV analysis, exploring ultra short-term measurements, selecting self-contained clips for viewing, and considering post-task baselines for a more accurate resting state representation. Despite limitations due to the small sample size, this study underscores the potential of HR and HRV as measures of immersion in translated audiovisual products, emphasising the need for larger sample sizes in future research to enhance statistical power and generalizability.

Variations in Heart Rate Variability and Physiological Responses during Analog Space Missions: An Exploratory Study

Variations in Heart Rate Variability and Physiological Responses during Analog Space Missions: An Exploratory Study

Beta-adrenergic reactivity of erythrocyte membranes in adolescents with supraventricular and ventricular arrhythmias before and after radiofrequency ablation

Aim. To evaluate β-adrenergic reactivity of erythrocyte membranes (β-ARM) in adolescents with ventricular and supraventricular arrhythmias before and after radiofrequency ablation (RFA) of heart rhythm disturbances.Materials and methods. The study included 49 adolescents aged 11–17 years, of which 15 had Wolff – Parkinson – White pattern (WPW), 13 – WPW syndrome, 10 – atrioventricular nodal reentry tachycardia (AVNRT), and 11 – ventricular arrhythmia (VA). The control group consisted of 11 adolescents without cardiovascular pathology. All patients received surgical treatment for heart rhythm disturbances (HRD) using RFA. In patients with HRD, β-ARM was determined by a set of reagents BETA-ARM AGAT (AGAT LLC, Russia) before RFA and 3 days after it. In the control group, the parameter was determined at the stage of inclusion in the study.Results. In adolescents with supraventricular arrhythmias, median values of β-ARM did not differ significantly from the control group. RFA in adolescents in these groups did not affect the value of β-ARM on day 3 after the surgery. In adolescents with VA, the median value of β-ARM was initially higher than in the control group (p = 0.026). On day 3 after RFA, an increase in β-ARM was noted in this group (p = 0.028) compared to baseline values.Conclusion. Activation of the sympathetic nervous system plays a significant role in the pathogenesis of VA in adolescence. The study showed the possibility of using β-ARM to assess the state of the sympathetic nervous system in patients with methodological limitations in analyzing heart rate variability.

Using a virtual reality game to train biofeedback-based regulation under stress conditions.

Physiological regulation strategies can be effective in reducing anxiety. However, while these strategies are often learned and practised under low-stress conditions, they are more likely to be required under conditions of high stress. We created virtual reality (VR) biofeedback games to both teach participants a breathing technique and then practise that technique under stress. We present two studies: the first provides a proof of concept, demonstrating that participants can apply the breathing technique during stress, with a significant lowering of both respiration rate and increase in heart rate variability (HRV) under stress (p < .001). The second study explicitly evaluated the effectiveness of training by comparing trained and untrained groups. Training was associated with a significantly greater HRV (p = .008) under stress. In within-group comparisons of HRV during stress compared to a baseline stressor presented before training, the trained group showed a significantly greater increase compared to untrained controls (p = .025). Our results show the feasibility and potential effectiveness of VR-based games for biofeedback training under experimentally applied stress. This may offer the opportunity for clinical techniques to more closely reflect the circumstances under which those techniques will be required.