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Sensors (Basel, Switzerland) Jun 2024Heart rate variability (HRV) is related to cardiac vagal control and emotional regulation and an index for cardiac vagal control and cardiac autonomic activity. This...
Heart rate variability (HRV) is related to cardiac vagal control and emotional regulation and an index for cardiac vagal control and cardiac autonomic activity. This study aimed to develop the Taiwan HRV normative database covering individuals aged 20 to 70 years and to assess its diagnosing validity in patients with major depressive disorder (MDD). A total of 311 healthy participants were in the HRV normative database and divided into five groups in 10-year age groups, and then the means and standard deviations of the HRV indices were calculated. We recruited 272 patients with MDD for cross-validation, compared their HRV indices with the normative database, and then converted them to Z-scores to explore the deviation of HRV in MDD patients from healthy groups. The results found a gradual decline in HRV indices with advancing age in the HC group, and females in the HC group exhibit higher cardiac vagal control and parasympathetic activity than males. Conversely, patients in the MDD group demonstrate lower HRV indices than those in the HC group, with their symptoms of depression and anxiety showing a negative correlation with HRV indices. The Taiwan HRV normative database has good psychometric characteristics of cross-validation.
Topics: Humans; Heart Rate; Depressive Disorder, Major; Male; Female; Adult; Middle Aged; Aged; Autonomic Nervous System; Young Adult; Databases, Factual; Taiwan; Electrocardiography; Heart
PubMed: 38931788
DOI: 10.3390/s24124003 -
Nutrients Jun 2024Guarana (GUA), a Brazilian seed extract, contains caffeine and other bioactive compounds that may have psychoactive effects. To assess the acute effects of GUA compared... (Randomized Controlled Trial)
Randomized Controlled Trial
Guarana (GUA), a Brazilian seed extract, contains caffeine and other bioactive compounds that may have psychoactive effects. To assess the acute effects of GUA compared to a low dose of caffeine (CAF) on cognitive and mood parameters, twenty participants completed a double-blind, crossover experiment where they ingested capsules containing the following: (1) 100 mg CAF, (2) 500 mg GUA containing 130 mg caffeine, or (3) placebo (PLA). Cognitive tests (Simon and 2N-Back Task) were performed at the baseline (pre-ingestion) and 60 min after ingestion. The response time for the cognitive tests and heart rate variability were unaffected ( > 0.05) by treatment, although 2N-Back was overall faster ( = 0.001) across time. The accuracy in the 2N-Back Task showed a significant interaction effect ( = 0.029) due to higher post-ingestion versus pre-ingestion levels ( = 0.033), but only with the PLA. The supplements also had no effect on cognitive measures following physical fatigue ( = 11). There was an interaction effect on perceived mental energy, where the pre-ingestion of GUA had lower mental pep ratings compared to post-ingestion ( = 0.006) and post-exercise ( = 0.018) levels. Neither the acute ingestion of GUA nor low dose of CAF influenced cognitive performance or provided consistent benefit on mood or mental workload through vagal modulation. Additional investigations are beneficial to determining the lowest effective dose for CAF or GUA to influence mood and/or cognitive performance.
Topics: Humans; Caffeine; Paullinia; Male; Cross-Over Studies; Double-Blind Method; Cognition; Adult; Young Adult; Female; Heart Rate; Affect; Vagus Nerve; Plant Extracts; Dietary Supplements
PubMed: 38931247
DOI: 10.3390/nu16121892 -
Life (Basel, Switzerland) Jun 2024Stress is recognized as a significant trigger and exacerbator of various medical conditions, particularly in the field of cardiovascular disease (CVD). Given that heart... (Review)
Review
Stress is recognized as a significant trigger and exacerbator of various medical conditions, particularly in the field of cardiovascular disease (CVD). Given that heart rate variability (HRV) offers insight into the functioning of the autonomic nervous system and has been identified as a predictive factor for increased cardiovascular mortality, exploring the correlation between stress and HRV is pertinent. We systematically reviewed trials where researchers investigated the effects of stress-reducing interventions on biomarkers and time-domain/frequency-domain parameters of HRV in CVD. Eligible studies underwent meta-analysis utilizing a random-effects model. The meta-analysis showed overall beneficial effects of stress-reducing interventions on HRV for the standard deviation of Normal-to-Normal intervals (SDNN) in short-term and 24 h assessments, as well as for the low-frequency power (LF) in short-term assessment. Overall effect sizes were notably high and showed significant -values (short-term SDNN: MD = 6.43, = 0.01; 24 h SDNN: MD = 10.92, = 0.004; short-term LF: MD = 160.11, < 0.001). Our findings highlight the significant impact of stress-reducing interventions in modulating HRV by influencing short-term SDNN and LF parameters, as well as the 24 h assessment of SDNN. These results emphasize the importance of stress-reducing measures in lowering the risk of further progression in CVD and improving patient outcomes.
PubMed: 38929732
DOI: 10.3390/life14060749 -
Diagnostics (Basel, Switzerland) Jun 2024Thyroid hormones have a pivotal role in controlling metabolic processes, cardiovascular function, and autonomic nervous system activity. Hypothyroidism, a prevalent...
Thyroid hormones have a pivotal role in controlling metabolic processes, cardiovascular function, and autonomic nervous system activity. Hypothyroidism, a prevalent endocrine illness marked by inadequate production of thyroid hormone, has been linked to different cardiovascular abnormalities, including alterations in heart rate variability (HRV). The study included 110 patients with hypothyroid disorder. Participants underwent clinical assessments, including thyroid function tests and HRV analysis. HRV, a measure of the variation in time intervals between heartbeats, serves as an indicator of autonomic nervous system activity and cardiovascular health. The HRV values were acquired using continuous 24-h electrocardiogram (ECG) monitoring in individuals with hypothyroidism, as well as after a treatment period of 3 months. All patients exhibited cardiovascular symptoms like palpitations or fatigue but showed no discernible cardiac pathology or other conditions associated with cardiac disease. The findings of our study demonstrate associations between hypothyroidism and alterations in heart rate variability (HRV) parameters. These results illustrate the possible influence of thyroid dysfunction on the regulation of cardiac autonomic function.
PubMed: 38928676
DOI: 10.3390/diagnostics14121261 -
International Journal of Molecular... Jun 2024The influence of accelerated electrons on neuronal structures is scarcely explored compared to gamma and X-rays. This study aims to investigate the effects of...
The influence of accelerated electrons on neuronal structures is scarcely explored compared to gamma and X-rays. This study aims to investigate the effects of accelerated electron radiation on some pivotal neurotransmitter circuits (cholinergic and serotonergic) of rats' myenteric plexus. Male Wistar rats were irradiated with an electron beam (9 MeV, 5 Gy) generated by a multimodality linear accelerator. The contractile activity of isolated smooth muscle samples from the gastric corpus was measured. Furthermore, an electrical stimulation (200 μs, 20 Hz, 50 s, 60 V) was performed on the samples and an assessment of the cholinergic and serotonergic circuits was made. Five days after irradiation, the recorded mechanical responses were biphasic-contraction/relaxation in controls and contraction/contraction in irradiated samples. The nature of the contractile phase of control samples was cholinergic with serotonin involvement. The relaxation phase involved ACh-induced nitric oxide release from gastric neurons. There was a significant increase in serotonergic involvement during the first and second contractile phases of the irradiated samples, along with a diminished role of acetylcholine in the first phase. This study demonstrates an increased involvement of serotonergic neurotransmitter circuits in the gastric myenteric plexus caused by radiation with accelerated electrons.
Topics: Animals; Myenteric Plexus; Male; Rats; Rats, Wistar; Stomach; Electrons; Muscle, Smooth; Serotonin; Muscle Contraction; Acetylcholine; Nitric Oxide
PubMed: 38928511
DOI: 10.3390/ijms25126807 -
Bioengineering (Basel, Switzerland) May 2024Physiological phenomena exhibit complex behaviours arising at multiple time scales. To investigate them, techniques derived from chaos theory were applied to...
Physiological phenomena exhibit complex behaviours arising at multiple time scales. To investigate them, techniques derived from chaos theory were applied to physiological signals, providing promising results in distinguishing between healthy and pathological states. Fractal-like properties of electrodermal activity (EDA), a well-validated tool for monitoring the autonomic nervous system state, have been reported in previous literature. This study proposes the multiscale complexity index of electrodermal activity (MComEDA) to discern different autonomic responses based on EDA signals. This method builds upon our previously proposed algorithm, ComEDA, and it is empowered with a coarse-graining procedure to provide a view at multiple time scales of the EDA response. We tested MComEDA's performance on the EDA signals of two publicly available datasets, i.e., the Continuously Annotated Signals of Emotion (CASE) dataset and the Affect, Personality and Mood Research on Individuals and Groups (AMIGOS) dataset, both containing physiological data recorded from healthy participants during the view of ultra-short emotional video clips. Our results highlighted that the values of MComEDA were significantly different (-value < 0.05 after Wilcoxon signed rank test with Bonferroni's correction) when comparing high- and low-arousal stimuli. Furthermore, MComEDA outperformed the single-scale approach in discriminating among different valence levels of high-arousal stimuli, e.g., showing significantly different values for scary and amusing stimuli (-value = 0.024). These findings suggest that a multiscale approach to the nonlinear analysis of EDA signals can improve the information gathered on task-specific autonomic response, even when ultra-short time series are considered.
PubMed: 38927756
DOI: 10.3390/bioengineering11060520 -
Biomedicines Jun 2024Patients with major depressive disorder (MDD) have an increased risk for cardiac events. This is partly attributed to a disbalance of the autonomic nervous system (ANS)...
Patients with major depressive disorder (MDD) have an increased risk for cardiac events. This is partly attributed to a disbalance of the autonomic nervous system (ANS) indicated by a reduced vagal tone and a (relative) sympathetic hyperactivity. However, in most studies, heart rate variability (HRV) was only examined while resting. So far, it remains unclear whether the dysbalance of the ANS in patients with MDD is restricted to resting or whether it is also evident during sympathetic and parasympathetic activation. The aim of this study was to compare the responses of the ANS to challenges that stimulated the sympathetic and, respectively, the parasympathetic nervous systems in patients with MDD. Forty-six patients with MDD (female 27 (58.7%), mean age 44 ± 17 years) and 46 healthy controls (female 26 (56.5%), mean age 44 ± 20 years) underwent measurement of time- and frequency-dependent domains of HRV at rest, while standing (sympathetic challenge), and during slow-paced breathing (SPB, vagal, i.e., parasympathetic challenge). Patients with MDD showed a higher heart rate, a reduced HRV, and a diminished vagal tone during resting, standing, and SPB compared to controls. Patients with MDD and controls responded similarly to sympathetic and vagal activation. However, the extent of modulation of the ANS was impaired in patients with MDD, who showed a reduced decrease in the vagal tone but also a reduced increase in sympathetic activity when switching from resting to standing. Assessing changes in the ANS during sympathetic and vagal activation via respective challenges might serve as a future biomarker and help to allocate patients with MDD to therapies like HRV biofeedback and psychotherapy that were recently found to modulate the vagal tone.
PubMed: 38927475
DOI: 10.3390/biomedicines12061268 -
Biomedicines May 2024A temporal reduction in the cardiovascular autonomic responses predisposes patients to cardiovascular instability after a viral infection and therefore increases the...
PURPOSE
A temporal reduction in the cardiovascular autonomic responses predisposes patients to cardiovascular instability after a viral infection and therefore increases the risk of associated complications. These findings have not been replicated in a bacterial infection. This pilot study will explore the prevalence of cardiovascular autonomic dysfunction (CAD) in hospitalized patients with a bacterial infection.
METHODS
A longitudinal observational pilot study was conducted. Fifty participants were included: 13 and 37 participants in the infection group and healthy group, respectively. Recruitment and data collection were carried out during a two-year period. Participants were followed up for 6 weeks: all participants' cardiovascular function was assessed at baseline (week 1) and reassessed subsequently at week 6 so that the progression of the autonomic function could be evaluated over that period of time. The collected data were thereafter analyzed using STATA/SE version 16.1 (StataCorp). The Fisher Exact test, McNemar exact test, Mann-Whitney test and Wilcoxon test were used for data analysis.
RESULTS
32.4% of the participants in the healthy group were males ( = 12) and 67.6% were females ( = 25). Participants' age ranged from 33 years old to 76 years old with the majority being 40-60 years of age (62.1%) SD ). Heart rate variability (HRV) in response to Valsalva Maneuver, metronome breathing, standing and sustained handgrip in the infection group was lower than in the healthy group throughout the weeks. Moreover, both the HRV in response to metronome breathing and standing up showed a statistically significant difference when the mean values were compared between both groups in week 1 ( = 0.03 and = 0.013). The prevalence of CAD was significantly higher in the infection group compared to healthy volunteers, both at the beginning of the study ( = 0.018) and at the end of follow up ( = 0.057), when all patients had been discharged.
CONCLUSIONS
CAD, as assessed by the HRV, is a common finding during the recovery period of a bacterial infection, even after 6 weeks post-hospital admission. This may increase the risk of complications and cardiovascular instability. It may therefore be of value to conduct a wider scale study to further evaluate this aspect so recommendations can be made for the cardiovascular autonomic assessment of patients while they are recovering from a bacterial infectious process.
PubMed: 38927426
DOI: 10.3390/biomedicines12061219 -
BMC Sports Science, Medicine &... Jun 2024Vagally-mediated heart rate variability (vm-HRV) shows promise as a biomarker of internal training load (ITL) during exergame-based training or motor-cognitive training...
Test-retest reliability and validity of vagally-mediated heart rate variability to monitor internal training load in older adults: a within-subjects (repeated-measures) randomized study.
BACKGROUND
Vagally-mediated heart rate variability (vm-HRV) shows promise as a biomarker of internal training load (ITL) during exergame-based training or motor-cognitive training in general. This study evaluated the test-retest reliability of vm-HRV during exergaming in healthy older adults (HOA) and its validity to monitor ITL.
METHODS
A within-subjects (repeated-measures) randomized study was conducted that included baseline assessments and 4 measurement sessions. Participants played 5 exergames at 3 standardized levels of external task demands (i.e., "easy", "challenging", and "excessive") in random order for 90 s. Test-retest reliability was assessed on the basis of repeated-measures analyses of variance (ANOVA), intraclass correlation coefficients (ICC), standard errors of measurement (SEM), and smallest detectable differences (SDD). Validity was determined by examining the effect of game level on vm-HRV in the ANOVA.
RESULTS
Fourty-three HOA (67.0 ± 7.0 years; 58.1% females (25 females, 18 males); body mass index = 23.7 ± 3.0 kg·m) were included. Mean R-R time intervals (mRR) and parasympathetic nervous system tone index (PNS-Index) exhibited mostly good to excellent relative test-retest reliability with no systematic error. Mean SEM% and SDD% were 36.4% and 100.7% for mRR, and 44.6% and 123.7% for PNS-Index, respectively. Significant differences in mRR and PNS-Index were observed between standardized levels of external task demands, with mostly large effect sizes (mean r = 0.847). These results persisted irrespective of the type of neurocognitive domain trained and when only motoric and cognitive demands were manipulated while physical intensity was kept constant. The remaining vm-HRV parameters showed inconsistent or poor reliability and validity.
CONCLUSION
Only mRR and PNS-Index demonstrated reliable measurement and served as valid biomarkers for ITL during exergaming at a group level. Nonetheless, the presence of large SEMs hampers the detection of individual changes over time and suggests insufficient precision of these measurements at the individual level. Future research should further investigate the reliability and validity of vm-HRV with a specific focus on comparing different measurement methodologies and exercise conditions, particularly focusing on ultra-short-term HRV measurements, and investigate the potential implications (i.e., superiority to other markers of ITL or monitoring strategies?) of using vm-HRV as a biomarker of ITL.
PubMed: 38926777
DOI: 10.1186/s13102-024-00929-y -
BMJ Open Jun 2024Chronic stress can cause an imbalance within the autonomic nervous system, thereby affecting cardiovascular and mental health. Physical activity (PA) may have a positive... (Observational Study)
Observational Study
INTRODUCTION
Chronic stress can cause an imbalance within the autonomic nervous system, thereby affecting cardiovascular and mental health. Physical activity (PA) may have a positive effect on the autonomic nervous system and stress-related disorders, such as depression and burnout. Heart rate variability (HRV) is a non-invasive marker of the autonomic nervous system. However, limited and inconsistent data exist on the exact relationship between HRV, PA and depression and burnout symptoms. The HARMODI study aims to explore whether HRV is a feasible marker of depression and burnout symptoms and aims to evaluate the role of PA in the treatment of stress-related disorders.
METHODS AND ANALYSES
This is an observational study with a cross-sectional up to 8 week follow-up study design. A total of 153 patients, undergoing psychiatric inpatient treatment with burnout syndrome (Z73) and depressive episode (F32 or F33) or adjustment disorder (F43.2), will be recruited. Data on depression and burnout symptoms, HRV recordings (24-hour, supine, standing and exercise stress test), cognitive function, cardiorespiratory fitness, cardiovascular health, balance and strength will be collected at baseline (T1) and after up to 8 weeks (T2). Continuous data on PA and Ecological Momentary Assessments of exhaustion, mood and tension will be monitored daily throughout inpatient treatment. Multiple regression models, adjusted for potential confounders, will assess the association between HRV as the primary outcome, PA and depression and burnout severity score.
ETHICS AND DISSEMINATION
The protocol has been approved by Swiss Ethics Committee, Cantonal Ethics Committee Zürich. Results of HARMODI will be disseminated through peer-reviewed journals and conference presentations.
TRIAL REGISTRATION NUMBER
NCT05874856.
Topics: Humans; Heart Rate; Cross-Sectional Studies; Exercise; Depression; Follow-Up Studies; Male; Adult; Burnout, Psychological; Female; Inpatients; Autonomic Nervous System; Middle Aged
PubMed: 38925684
DOI: 10.1136/bmjopen-2023-081299