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Trials Mar 2024In healthy people, the "fight-or-flight" sympathetic system is counterbalanced by the "rest-and-digest" parasympathetic system. As we grow older, the parasympathetic...
BACKGROUND
In healthy people, the "fight-or-flight" sympathetic system is counterbalanced by the "rest-and-digest" parasympathetic system. As we grow older, the parasympathetic system declines as the sympathetic system becomes hyperactive. In our prior heart rate variability biofeedback and emotion regulation (HRV-ER) clinical trial, we found that increasing parasympathetic activity through daily practice of slow-paced breathing significantly decreased plasma amyloid-β (Aβ) in healthy younger and older adults. In healthy adults, higher plasma Aβ is associated with greater risk of Alzheimer's disease (AD). Our primary goal of this trial is to reproduce and extend our initial findings regarding effects of slow-paced breathing on Aβ. Our secondary objectives are to examine the effects of daily slow-paced breathing on brain structure and the rate of learning.
METHODS
Adults aged 50-70 have been randomized to practice one of two breathing protocols twice daily for 9 weeks: (1) "slow-paced breathing condition" involving daily cognitive training followed by slow-paced breathing designed to maximize heart rate oscillations or (2) "random-paced breathing condition" involving daily cognitive training followed by random-paced breathing to avoid increasing heart rate oscillations. The primary outcomes are plasma Aβ40 and Aβ42 levels and plasma Aβ42/40 ratio. The secondary outcomes are brain perivascular space volume, hippocampal volume, and learning rates measured by cognitive training performance. Other pre-registered outcomes include plasma pTau-181/tTau ratio and urine Aβ42. Recruitment began in January 2023. Interventions are ongoing and will be completed by the end of 2023.
DISCUSSION
Our HRV-ER trial was groundbreaking in demonstrating that a behavioral intervention can reduce plasma Aβ levels relative to a randomized control group. We aim to reproduce these findings while testing effects on brain clearance pathways and cognition.
TRIAL REGISTRATION
ClinicalTrials.gov NCT05602220. Registered on January 12, 2023.
Topics: Aged; Humans; Attention; Biofeedback, Psychology; Cognition; Heart Rate; Randomized Controlled Trials as Topic; Respiration; Middle Aged
PubMed: 38491546
DOI: 10.1186/s13063-024-07943-y -
American Journal of Physiology. Heart... Aug 2023Individuals with chronic heart failure (CHF) have an increased risk of ventricular arrhythmias, which has been linked to pathological cellular remodeling and may also be...
Individuals with chronic heart failure (CHF) have an increased risk of ventricular arrhythmias, which has been linked to pathological cellular remodeling and may also be mediated by changes in heart rate. Heart rate typically fluctuates on a timescale ranging from seconds to hours, termed heart rate variability (HRV). This variability is reduced in CHF, and this HRV reduction is associated with a greater risk for arrhythmias. Furthermore, variations in heart rate influence the formation of proarrhythmic alternans, a beat-to-beat alternation in the action potential duration (APD), or intracellular calcium (Ca). In this study, we investigate how long-term changes in heart rate and electrical remodeling associated with CHF influence alternans formation. We measure key statistical properties of the RR-interval sequences from ECGs of individuals with normal sinus rhythm (NSR) and CHF. Patient-specific RR-interval sequences and synthetic sequences (randomly generated to mimicking these statistical properties) are used as the pacing protocol for a discrete time-coupled map model that governs APD and intracellular Ca handling of a single cardiac myocyte, modified to account for pathological electrical remodeling in CHF. Patient-specific simulations show that beat-to-beat differences in APD vary temporally in both populations, with alternans formation more prevalent in CHF. Parameter studies using synthetic sequences demonstrate that increasing the autocorrelation time or mean RR-interval reduces APD alternations, whereas increasing the RR-interval standard deviation leads to higher alternans magnitudes. Importantly, we find that although both the CHF-associated changes in heart rate and electrical remodeling influence alternans formation, variations in heart rate may be more influential. Using patient-specific data, we show that both the changes in heart rate and electrical remodeling associated with chronic heart failure influence the formation of proarrhythmic alternans in the heart.
Topics: Humans; Heart Rate; Atrial Remodeling; Arrhythmias, Cardiac; Heart Failure; Myocytes, Cardiac; Action Potentials; Calcium
PubMed: 37417871
DOI: 10.1152/ajpheart.00220.2023 -
Science Progress 2024To ensure both optimal health and performances, monitoring physiological and psychological states is of main importance for athletes. It is well known that monitoring...
To ensure both optimal health and performances, monitoring physiological and psychological states is of main importance for athletes. It is well known that monitoring heart rate variability and using validated questionnaires is useful for monitoring both the health and training status of athletes of different sports. Motorsports such as rally require high levels of physical and mental preparation thus information about psychophysiological status of rally athletes is fundamental. of this study was to assess the autonomic regulation, stress, recovery conditions of one driver and one co-driver competing at the Italian National Rally Championship during their competition period. Heart rate variability parameters, acute recovery and stress states were assessed the day before, during the two days of race and the day following the races. Results showed that driver and co-driver had a sharp decrease of mean RR intervals, root mean square of successive differences between normal heartbeats, and standard deviation of the N-N interval during race days, while the stress index showed the inverse trend, and this behaviour was clearly visible in the Poincaré plots and power spectrum density graphs. The acute recovery and stress states questionnaire showed significant differences in recovery and stress scoring for the driver but not for the co-driver, although the trends were similar. This study describes the psychophysiological demands of a rally competition period suggesting that a daily evaluation of heart rate variability, recovery, stress states is useful for monitoring health status in rally athletes and could be implemented to make decision about training and recovery strategies.
Topics: Humans; Heart Rate; Sports; Athletes; Surveys and Questionnaires
PubMed: 38179721
DOI: 10.1177/00368504231223034 -
Journal of Affective Disorders Nov 2023Patients with common mental disorders (depression, anxiety, and somatic symptoms) often exhibit lower heart rate variability (HRV) than healthy individuals. Under the...
BACKGROUND
Patients with common mental disorders (depression, anxiety, and somatic symptoms) often exhibit lower heart rate variability (HRV) than healthy individuals. Under the hypothesis that disorder status affects cognitive function, we examined whether neuropsychological features can be mediators between psychopathologies and HRV and possible sex differences.
METHODS
We recruited 359 individuals (aged 42.47 ± 12.23) with and without common mental disorders. Questionnaires were used to measure their psychopathologies. Eight tests from the Cambridge Neuropsychological Test Automated Battery were selected to measure neuropsychological functions. Resting-state HRV measurements were obtained for 5 min. The associations among these constructs were analyzed using multiple linear regression analysis and structural equation modelling.
RESULTS
Among women, Reaction Time (RTI, a task of psychomotor speed) indicator mediated the relationship between depression and low-frequency power (LF); Emotion Recognition Task (ERT, a task of emotional regulation) indicator mediated the relationship between health anxiety and high-frequency power (HF). Among men, Intra-Extra Dimensional Set Shift (IED, a task of shifting) indicator mediated the relationship between depression and LF; Match to Sample Visual Search (MTS, a task of selective attention) indicator mediated the relationship between health cognition and HF. The depression-RTI-LF pathway in women tended to lower HRV; whereas health anxiety-ERT-HF in women, depression-IED-LF and health cognition-MTS-HF in men tended to increase HRV.
LIMITATIONS
Possible medication effects; not directly measuring brain activity; only gathering resting-state HRV.
CONCLUSION
Our findings support the notion that neuropsychological features mediate the relationship between psychopathologies and HRV, and that sex differences exist.
Topics: Humans; Male; Female; Heart Rate; Sex Characteristics; Emotions; Anxiety; Attention
PubMed: 37562561
DOI: 10.1016/j.jad.2023.08.046 -
Attention, Perception & Psychophysics Aug 2023Important characteristics of the environment can be represented in the temporal pattern of sensory stimulation. In two experiments, we compared accuracy of temporal...
Important characteristics of the environment can be represented in the temporal pattern of sensory stimulation. In two experiments, we compared accuracy of temporal processing by different modalities. Experiment 1 examined binary categorization of rate for visual (V) or vibrotactile (T) stimulus pulses presented at either 4 or 6 Hz. Inter-pulse intervals were either constant or variable, perturbed by random Gaussian variates. Subjects categorized the rate of T pulse sequences more accurately than V sequences. In V conditions only, subjects disproportionately tended to mis-categorize 4-Hz pulse rates, for all but the most variable sequences. In Experiment 2, we compared gap detection thresholds across modalities, using the same V and T pulses from Experiment 1, as well as with bimodal (VT) pulses. Visual gap detection thresholds were larger (3[Formula: see text]) than tactile thresholds. Additionally, performance with VT stimuli seemed to be nearly completely dominated by their T components. Together, these results suggest (i) that vibrotactile temporal acuity surpasses visual temporal acuity, and (ii) that vibrotactile stimulation has considerable, untapped potential to convey temporal information like that needed for eyes-free alerting signals.
Topics: Humans; Heart Rate; Fingers; Time Perception; Visual Perception; Vibration; Touch; Touch Perception
PubMed: 37587355
DOI: 10.3758/s13414-023-02736-y -
International Journal of Environmental... Dec 2023Heart rate variability (HRV) is a measurement of the fluctuation of time between each heartbeat and reflects the function of the autonomic nervous system. HRV is an... (Review)
Review
Heart rate variability (HRV) is a measurement of the fluctuation of time between each heartbeat and reflects the function of the autonomic nervous system. HRV is an important indicator for both physical and mental status and for broad-scope diseases. In this review, we discuss how wearable devices can be used to monitor HRV, and we compare the HRV monitoring function among different devices. In addition, we have reviewed the recent progress in HRV tracking with wearable devices and its value in health monitoring and disease diagnosis. Although many challenges remain, we believe HRV tracking with wearable devices is a promising tool that can be used to improve personal health.
Topics: Heart Rate; Wearable Electronic Devices; Autonomic Nervous System; Monitoring, Physiologic; Heart Rate Determination
PubMed: 38131698
DOI: 10.3390/ijerph20247146 -
Scientific Reports Mar 2024Squatting is an active posture test used in assessing baroreflex sensitivity, and the array of patients a physiotherapist handles may benefit from this test to avoid the...
Squatting is an active posture test used in assessing baroreflex sensitivity, and the array of patients a physiotherapist handles may benefit from this test to avoid the adverse effects of exercise. Therefore, this study is designed to evaluate the effect of squatting on heart rate and blood pressure among undergraduate students. 35 males (mean age = 22.94 ± 1.846) and 40 females (mean age = 22.28 ± 2.075) participated in this experimental study. Demographic data and baseline cardiovascular parameters (blood pressure and heart rate) were taken before exercise. The exercise protocol, the squatting stress test, was done for 2 min, after which post-exercise blood pressure and heart rate were taken at one minute each. A repeated measure ANOVA and independent t-test were used to analyse the difference at the 0.05 alpha level. It was found that there was a significant difference between pre-exercise in lying and squatting post-exercise blood pressure and heart rate in the first and second minutes (p < 0.01), pre-exercise in lying and standing post-exercise blood pressure and heart rate in the first and second minutes (p < 0.01), pre-exercise in standing and standing post-exercise blood pressure and heart rate in the first and second minutes (p < 0.01), and pre-exercise in standing and squatting post-exercise blood pressure and heart rate in the first and second minutes (p < 0.01). Also, there was a significant difference in pre-exercise heart rate between lying and standing (p < 0.05) and not between the first minute and second minute post-squatting or standing exercise systolic blood pressure (p = 0.588) or diastolic blood pressure (p = 0.22-1). In conclusion, squatting trials among undergraduates revealed some statistically significant changes, especially between the cardiopulmonary parameters obtained in a standing position compared to lying and those measured after one minute. Therefore, caution should be observed when administering exercises that require changes in posture.
Topics: Male; Female; Humans; Young Adult; Adult; Posture; Blood Pressure; Heart Rate; Baroreflex; Students
PubMed: 38454093
DOI: 10.1038/s41598-024-56186-z -
Sensors (Basel, Switzerland) Aug 2023This study investigated the use of affect and physiological signals of heart rate, electrodermal activity, pupil dilation, and skin temperature to classify advertising...
This study investigated the use of affect and physiological signals of heart rate, electrodermal activity, pupil dilation, and skin temperature to classify advertising engagement. The ground truth for the affective and behavioral aspects of ad engagement was collected from 53 young adults using the User Engagement Scale. Three gradient-boosting classifiers, LightGBM (LGBM), HistGradientBoostingClassifier (HGBC), and XGBoost (XGB), were used along with signal fusion to evaluate the performance of different signal combinations as predictors of engagement. The classifiers trained on the fusion of skin temperature, valence, and tiredness (features = 5) performed better than those trained on all signals (features n = 30). The average AUC ROC scores for the fusion set were XGB = 0.68 (0.10), LGBM = 0.69 (0.07), and HGBC = 0.70 (0.11), compared to the lower scores for the set of all signals (XGB = 0.65 (0.11), LGBM = 0.66 (0.11), HGBC = 0.64 (0.10)). The results also show that the signal fusion set based on skin temperature outperforms the fusion sets of the other three signals. The main finding of this study is the role of specific physiological signals and how their fusion aids in more effective modeling of ad engagement while reducing the number of features.
Topics: Young Adult; Humans; Advertising; Heart Rate
PubMed: 37571700
DOI: 10.3390/s23156916 -
Journal of Clinical Monitoring and... Feb 2024Background- Subarachnoid hemorrhage (SAH) is one of the most devastating diseases with a high rate of morbidity and mortality. The heart rate variability (HRV) is a... (Review)
Review
Background- Subarachnoid hemorrhage (SAH) is one of the most devastating diseases with a high rate of morbidity and mortality. The heart rate variability (HRV) is a non-invasive method of monitoring various components of the autonomic nervous system activity that can be utilized to delineate autonomic dysfunctions associated with various physiological and pathological conditions. The reliability of HRV as a predictor of clinical outcome in aneurysmal subarachnoid hemorrhage (aSAH) is not yet well investigated in literature. Methods- A systematic review and in depth analysis of 10 articles on early HRV changes in SAH patients was performed. Results- This systematic review demonstrates a correlation between early changes in HRV indices (time and frequency domain) and the development of neuro-cardiogenic complications and poor neurologic outcome in patients with SAH. Conclusions- A correlation between absolute values or changes of the LF/HF ratio and neurologic and cardiovascular complications was found in multiple studies. Because of significant limitations of included studies, a large prospective study with proper handling of confounders is needed to generate high-quality recommendations regarding HRV as a predictor of post SAH complications and poor neurologic outcome.
Topics: Humans; Subarachnoid Hemorrhage; Heart Rate; Prospective Studies; Reproducibility of Results; Autonomic Nervous System
PubMed: 37335412
DOI: 10.1007/s10877-023-01043-z -
Journal of Human Hypertension Sep 2023This study aims to assess the associations of functional outcomes following acute ischemic stroke (IS) with ambulatory pulse rate (PR) and characterize the time-variant...
This study aims to assess the associations of functional outcomes following acute ischemic stroke (IS) with ambulatory pulse rate (PR) and characterize the time-variant properties of the associations. The prospective cohort consisted of 1831 patients who had ambulatory blood pressure (BP) and PR monitoring following acute IS, and neurologic status evaluated at discharge and 3-month follow-up. The neurologic disability was defined as modified Rankin Scale ≥3. Logistic regression and generalized penalized functional regression models were used to examine the associations of ambulatory BP and PR with neurologic disability. Adjusting for covariates, the neurologic disability at discharge and 3-month was associated with high average 24-h, daytime, and nocturnal PR (odds ratio, OR = 1.20-1.34; p < 0.05 for all), high standard derivation of nocturnal PR (OR = 1.19 and 1.32; p < 0.05 for both), and low nocturnal PR decline (OR = 0.76 and 0.76; p < 0.05 for both). The OR functions of ambulatory PR on neurologic disability were "W-shaped" from 0 a.m. to 12 p.m., with ORs >1 in the wee hours and at noon, and ORs <1 before dawn and at night. The ambulatory BP profiles were not associated with neurologic disability at discharge or 3-month. The ambulatory PR is associated with the risk of short-term neurologic disability of stroke patients, with four different phases in a 24-h cycle. Ambulatory PR monitoring, especially nocturnal PR monitoring, has significant clinical implications for the prevention of short-term neurologic disability in stroke inpatients.
Topics: Humans; Hypertension; Ischemic Stroke; Heart Rate; Blood Pressure Monitoring, Ambulatory; Prospective Studies; Stroke
PubMed: 36220910
DOI: 10.1038/s41371-022-00763-0