Autonomic and endocrine control of cardiovascular function

Bone mechanical loading reduces heart rate and increases heart rate variability in mice

Cardiovascular disease and osteoporosis are clinically associated. Bone adapts to mechanical forces by altering its overall structure and mass. In response to mechanical strain bone cells release signaling molecules and activate the nervous system. Bone also exhibits endocrine functions that modulate a number of tissues including the heart. We hypothesized that bone mechanical loading acutely alters cardiac function via neural and/or endocrine mechanisms. To test this hypothesis, we performed in vivo tibia mechanical loading in anesthetized mice while monitoring heart parameters using electrocardiogram (ECG). An immediate, transient reduction in resting heart rate was observed during tibial loading in both adult male and female mice (p < 0.01) with concurrent increases in heart rate variability (HRV) (p < 0.01). ECG intervals, PR, QRS and QTc were unaffected with loading. In further studies, we found that at least 3 N of load was necessary to elicit this heart response in adult mice. With aging to 11-12 months the responsiveness of the heart to loading was blunted, suggesting this bone-heart connection may weaken with age. Administration of lidocaine around the tibia significantly diminished the heart rate response to bone loading (p < 0.05). Moreover, pre-treatment with sympathetic antagonist propranolol inhibited this heart rate response to loading (p < 0.05), while parasympathetic antagonist atropine did not (p > 0.05). This suggests that a neuronal afferent pathway in the hindlimb and reduction in efferent sympathetic tone mediate this bone-neuro-heart reflex. In conclusion, the findings that tibia bone loading age-dependently modulates heart function support the concept of physiological coupling of the skeletal and cardiovascular systems.

The psychostimulant drug, fenethylline (captagon): Health risks, addiction and the global impact of illicit trade

Fenethylline (street name, captagon) is a synthetic amphetamine-type stimulant that is emerging as a significant public health and security concern, particularly in the Middle East. This systematic review synthesizes original research articles, epidemiological studies, systematic reviews, policy analyses, and case reports to provide a comprehensive analysis of fenethylline's health impacts, addiction potential, and dynamics of illicit trade. Initially developed for therapeutic use, fenethylline illicit production and use have escalated, raising concern about its physiological, psychological, and socio-economic impacts. This stimulant profoundly affects the central nervous system, enhancing wakefulness, concentration, and physical stamina while inducing euphoria. These effects come at the cost of serious adverse health outcomes, particularly with prolonged or heavy use, including cardiovascular complications, neurological damage, and addiction. The dependence-forming nature of captagon contributes to escalating substance use disorders, impacting healthcare systems. Beyond its biomedical implications, fenethylline trafficking has become a global issue, with supply chains deeply intertwined with politically unstable regions where illicit economies thrive. The geopolitical dimensions of captagon's trade amplify its global security threat, influencing international relations and regional stability. This paper underscores the urgent need for systematic data collection and coordinated efforts to regulate illicit fenethylline production and distribution. Strategies such as improved surveillance, public health interventions, and international cooperation are essential to mitigate its escalating risks. Addressing this issue requires a multidisciplinary approach, integrating public health, law enforcement, and policy development to curb its impact on global health and security.

Treatments for weight gain in schizophrenia

PURPOSE OF REVIEW

Obesity and related metabolic disorders are extremely common in psychiatric patients, particularly in those with schizophrenia. Elucidating this link's neurobiology may inform clinicians and researchers of rational therapeutic approaches necessary to optimize clinical outcomes.

RECENT FINDINGS

Current literature highlights the pivotal role of the inflammation-oxidative stress-insulin resistance loop in the pathophysiology of both metabolic and neuropsychiatric disorders. The concept of 'diabetophrenia' is put forward to highlight the overlapping neurobiological mechanisms underlying metabolic dysfunction and schizophrenia symptoms. Innovative treatments, including the combination of xanomeline with trospium and incretin-based medicines, demonstrate encouraging potential in addressing such complex health challenges.

SUMMARY

The nuanced dynamics of chronic inflammation and psychiatric symptomatology underscore the significance of addressing both metabolic and mental health factors in a cohesive fashion while considering unique psychosocial contexts, dietary preferences, and lifestyle choices. A multidisciplinary strategy is essential for incorporating counseling, dietary interventions, behavioral therapies, and pharmacotherapy into the management of schizophrenia. The ensuing enhanced collaboration among healthcare professionals may render obsolete the prevailing siloed conceptualizations of mental disorders, opening new vistas for generating synergistic insights into the mind-body systems and leading to improved health and quality of life for patients with schizophrenia and other psychiatric conditions.

Exploring the dynamic relationships between nocturnal heart rate, sleep disruptions, anxiety levels, and depression severity over time in recurrent major depressive disorder

BACKGROUND

Elevated night resting heart rate (HR) has been associated with increased depression severity, yet the underlying mechanisms remain elusive. This study aimed to investigate the mediating role of sleep disturbance and the influence of anxiety on the relationship between night resting HR and depression severity.

METHODS

This is a secondary data analysis of data collected in the Remote Assessment of Disease and Relapse (RADAR) Major Depressive Disorder (MDD) longitudinal mobile health study, encompassing 461 participants (1774 observations) across three national centers (Netherlands, Spain, and the UK). Depression severity, anxiety, and sleep disturbance were assessed every three months. Night resting HR parameters in the 2 weeks preceding assessments were measured using a wrist-worn Fitbit device. Linear mixed models and causal mediation analysis were employed to examine the impact of sleep disturbance and anxiety on night resting HR on depression severity. Covariates included age, sex, BMI, smoking, alcohol consumption, antidepressant use, and comorbidities with other medical conditions.

RESULTS

Higher night resting HR was linked to subsequent depressive severity, through the mediation of sleep disturbance. Anxiety contributed to an exacerbated level of sleep disturbance, subsequently intensifying depression severity. Anxiety exhibited no direct effect on night resting HR.

CONCLUSIONS

Our findings underscore the mediating role of sleep disturbance in the effect of night resting HR on depression severity, and anxiety on depression severity. This insight has potential implications for early identification of indicators signalling worsening depression symptoms, enabling clinicians to initiate timely and responsive treatment measures.

Elevated blood pressure, stroke volume, and vascular tone in young women who use oral contraception

Use of hormonal contraception is important to consider as a risk or protective factor in the development of cardiovascular disease. Prior reports of short and long-term effects of hormonal contraception on cardiovascular disease allude to its potential for immediate and delayed cardiovascular effects, but the nature of direct early cardiovascular changes as the result of hormonal contraception use remains understudied. This cross-sectional data analysis add-on study compared differences in cardiovascular function of naturally cycling women (n = 90) and women using oral contraceptive pills (n = 35) at rest and in response to physiological breathing challenges that activated the sympathetic (paced sighing) or parasympathetic (slow paced breathing) nervous systems. Results showed women using oral contraception had elevated resting systolic blood pressure as well as increased stroke volume and shortened pulse transit time (i.e., vasoconstriction) relative to naturally cycling women. Despite resting differences, both groups responded similarly to breathing challenges. Elevated resting blood pressure and altered sympathetic control, even at preclinical levels, may increase physiological wear-and-tear, particularly if hormonal contraceptive use continues over long periods of time. These findings are particularly compelling considering the youth and health of the current sample.

Regulation of Cardiac Function by the Autonomic Nervous System

The autonomic nervous system is critical for regulating cardiovascular physiology. The neurocardiac axis encompasses multiple levels of control, including the motor circuits of the sympathetic and parasympathetic nervous systems, sensory neurons that contribute to cardiac reflexes, and the intrinsic cardiac nervous system that provides localized sensing and regulation of the heart. Disruption of these systems can lead to significant clinical conditions. Recent advances have enhanced our understanding of the autonomic control of the heart, detailing the specific neuronal populations involved and their physiologic roles. In this review, we discuss this research at each level of the neurocardiac axis. We conclude by discussing the clinical field of neurocardiology and attempts to translate this new understanding of neurocardiac physiology to the clinic. We highlight the contributions of autonomic dysfunction in prevalent cardiovascular diseases and assess the current status of novel neuroscience-based treatment approaches.

Adrenal Anatomy and Physiology

The adrenal glands are paired endocrine organs that play a vital role in maintaining homeostasis by regulating blood pressure, metabolism, electrolyte balance, and the body's response to stress. Each gland comprises the adrenal cortex, which produces steroid hormones, and the adrenal medulla, responsible for catecholamine synthesis. The cortex is further divided into three functional zones, the zona glomerulosa (mineralocorticoids), zona fasciculata (glucocorticoids), and zona reticularis (androgens), while the medulla secretes adrenaline, noradrenaline, and dopamine under sympathetic control. This article aims to provide a comprehensive overview of the adrenal glands, including their anatomical structure, embryological development, vascular supply, microscopic architecture, and physiological function. Additionally, the historical evolution of adrenal research and the impact of modern molecular advancements are discussed. Understanding the anatomy and function of adrenal gland is crucial for diagnosing and managing adrenal disorders, including hormonal deficiencies, hypersecretion syndromes, and adrenal neoplasms.

Vagal pathway activation links chronic stress to decline in intestinal stem cell function

Chronic stress adversely affects intestinal health, but the specific neural pathways linking the brain to intestinal tissue are not fully understood. Here, we show that chronic stress-induced activation of the central amygdala-dorsal motor nucleus of the vagus (CeA-DMV) pathway accelerates premature aging and impairs the stemness of intestinal stem cells (ISCs). This pathway influences ISC function independently of the microbiota, the hypothalamic-pituitary-adrenal (HPA) axis, the immune response, and the sympathetic nervous system (SNS). Under chronic stress, DMV-mediated vagal activation prompts cholinergic enteric neurons to release acetylcholine (ACh), which engages ISCs via the M3 muscarinic acetylcholine receptor (CHRM3). This interaction activates the p38 mitogen-activated protein kinase (MAPK) pathway, triggering growth arrest and mitochondrial fragmentation, thereby accelerating an aging-like decline in ISCs. Together, our findings provide insights into an alternative neural mechanism that links stress to intestinal dysfunction. Strategies targeting the DMV-associated vagal pathway represent potential therapeutic approaches for stress-induced intestinal diseases.

Physiological Data Collected From Wearable Devices Identify and Predict Inflammatory Bowel Disease Flares

BACKGROUND & AIMS

Wearable devices capture physiological signals noninvasively and passively. Many of these parameters have been linked to inflammatory bowel disease (IBD) activity. We evaluated the associative ability of several physiological metrics with IBD flares and how they change before the development of flare.

METHODS

Participants throughout the United States answered daily disease activity surveys and wore an Apple Watch (Apple), Fitbit (Google), or Oura Ring (Oura Health). These devices collected longitudinal heart rate (HR), resting heart rate (RHR), heart rate variability (HRV), steps, and oxygenation. C-reactive protein, erythrocyte sedimentation rate, and fecal calprotectin were collected as standard of care. Linear mixed-effect models were implemented to analyze HR, RHR, steps, and oxygenation, and cosinor mixed-effect models were applied to HRV circadian features. Mixed-effect logistic regression was used to determine the predictive ability of physiological metrics.

RESULTS

Three hundred and nine participants were enrolled across 36 states. Circadian patterns of HRV differed significantly between periods of inflammatory flare and remission and symptomatic flare and remission. Marginal means for HR and RHR were higher during periods of inflammatory flare and symptomatic flare. There were fewer daily steps during inflammatory flares. HRV, HR, and RHR differentiated whether participants with symptoms had inflammation. HRV, HR, RHR, steps, and oxygenation were significantly altered up to 7 weeks before inflammatory and symptomatic flares.

CONCLUSIONS

Longitudinally collected physiological metrics from wearable devices can identify and change before IBD flares, suggesting their feasibility to monitor and predict IBD activity.

Sex hormones correlate with heart rate variability in healthy women and this correlation is conserved in women with well-controlled type 2 diabetes mellitus

SUBJECTS AND METHODS

In this study, four groups of women were designated according to their health status (control or T2DM) and fertility status (premenopausal or postmenopausal). Five serum sex hormones were measured (estradiol, progesterone, testosterone, LH and FSH), and time-domain and frequency-domain HRV indices were determined during three conditions: supine position, active standing, and rhythmic breathing. For the complete sample (n=118), bivariate Pearson correlations and linear multiple regressions were used to analyze the relationship between sex hormones, HRV indices, and other independent variables, such as glycemia and age. A p-value <0.05 was considered as significant.

RESULTS

There were no differences in sex hormones or HRV indices when comparing the healthy and T2DM groups. All bivariate Pearson correlations were significant between sex hormones and HRV indices; estradiol, progesterone, and testosterone have positive correlations; meanwhile, LH and FSH were negative in the time-domain (SDNN, RMSSD, pNN20) and frequency domain (PLF and PHF) indices. Regression models adjusted for mean heartbeat intervals confirmed an association between all sex hormones and HRV indices. Estradiol maintained significance in the regression models for specific HRV indices during supine and active standing conditions even after adjusting for age and glucose levels.

CONCLUSIONS

All sex hormones correlate with HRV indices. Regression analysis confirms that this correlation is independent from the mean heartbeat interval. However, in regression models adjusted for age and glucose levels, only estradiol was found to be significant, and should be considered an important variable related to cardiovascular and autonomic balance in T2DM women and may provide crucial information to improve cardiovascular risk algorithms.

Investigating Cognitive Load and Autonomic Arousal During Voice Production and Vocal Auditory-Motor Adaptation

PURPOSE

Cognitive load and autonomic arousal are hypothesized to affect voice production, yet the nature of these relationships is unclear. The purpose of this study was to assess how cognitive load and autonomic arousal differentially affect voice production and vocal motor control.

METHOD

Physiological measures of autonomic arousal were recorded from 30 adults under different cognitive loads elicited by a Stroop task. In Experiment 1, voice acoustic measures were measured during speech production. In Experiment 2, fundamental frequency (fo) responses to predictably altered auditory feedback (sensorimotor adaptation) were measured. Mixed linear-effects models assessed relationships between variables. Changes between cognitive loads were compared among the two experiments.

RESULTS

In Experiment 1, increased cognitive load was associated with increases in sound pressure level, whereas increases in autonomic arousal measures (i.e., decreases in skin conductance rise time, pulse amplitude, and period) were related to decreases in cepstral peak prominence. Increased autonomic arousal (i.e., decreased pulse amplitude) was related to increased adaptation in Experiment 2. Participants who responded to increased cognitive load by decreasing fo during Experiment 1 showed more adaptation in Experiment 2.

CONCLUSION

Differential effects of cognitive load and autonomic arousal emphasize the importance of individual physiological variability when assessing how stress affects the voice.

Catecholamines in sepsis: pharmacological insights and clinical applications-a narrative review

Catecholamines, essential neurotransmitters and hormones, play a critical role in the body's physiological response to stress and are pivotal in the management of various clinical conditions, particularly in critical care settings. This narrative review delves into the pharmacological properties of catecholamines, including their mechanisms of action, pharmacokinetics, and pharmacodynamics. Key clinical applications of catecholamines, especially in the cardiovascular and immune systems, are highlighted, emphasizing their roles in modulating heart rate, vascular tone, and immune responses during critical conditions such as sepsis and septic shock. Additionally, the review explores catecholamines' immunomodulatory effects and their interactions with other therapeutic agents, such as corticosteroids, in the management of septic shock. Further research is suggested to optimize catecholamine usage and improve patient outcomes in critical care settings.

Exploring the impact of gentle stroking touch on psychophysiological regulation of inhibitory control

Touch has been shown to regulate emotions, stress responses, and physical pain. However, its impact on cognitive functions, such as inhibitory control, remains relatively understudied. In this experiment, we explored the effects of low-force, slow-moving touch-designed to optimally activate unmyelinated cutaneous low-threshold mechanoreceptor C-tactile (CT) afferents in human hairy skin-on inhibitory control and its psychophysiological correlates using the Stroop Task, a classic paradigm commonly employed to assess inhibitory control capacity. The Stroop Task was repeated twice before and once after receiving either gentle touch or no-touch. Participants were assigned to two groups: the touch group (n = 36), which received low-force, slow-moving touch on their forearms at a stroking velocity of ~3 cm/s, and the no-touch group (n = 36), which did not receive any touch stimulation. Changes in autonomic nervous system activity were also assessed by measuring heart rate variability (HRV) and skin conductance levels before and during cognitive performance. Compared to the no-touch group, participants who received gentle, low-force, slow-moving touch demonstrated faster responses and higher HRV during the Stroop Task. Additionally, within the touch group, individuals with higher HRV exhibited even quicker performance on the cognitive task. While we cannot draw definitive conclusions regarding the CT velocity-specific effect, these results provide preliminary evidence that low-force, slow-moving touch may influence cognitive processes involved in the inhibitory control of goal-irrelevant stimuli.

The effects of rhythmic handgrip exercise on muscle sympathetic nerve activity: A systematic review and meta-analysis

This systematic review and meta-analysis was conducted to quantify the sympathetic response to rhythmic handgrip exercise in healthy and diseased populations. Structured searches of databases were performed until June 12, 2024. We included all primary studies (other than systematic reviews and meta-analyses), and inclusion criteria were: population (all populations); intervention (rhythmic handgrip); comparator (baseline); and outcome (MSNA, BP, HR). Forty-nine studies (n = 930) were included. Burst frequency was elevated by 6.1 bursts/min during rhythmic handgrip (95 % CI, 4.52, 7.63; I2 = 53 %; p < 0.00001) across all populations. Similarly, burst incidence and total activity showed significant increases during handgrip (BI: MD, 3.0 bursts/100 hbs; 95 % CI, 0.11, 5.85; I2 = 0 %; p = 0.04; TA: MD, 49.4 a.u.; 95 % CI, 36.56, 62.20; I2 = 86 %; p < 0.00001). Subgroup analyses found greater responses in MSNA during rhythmic handgrip in healthy individuals compared to cardiovascular diseases and other conditions. Specifically, the change in burst frequency during handgrip (p = 0.0009) and total activity during handgrip (p < 0.00001) suggest a blunted sympathetic response to rhythmic handgrip in diseased populations. Meta-regression analyses in healthy populations found no relationship between the volume of handgrip applied with the associated change in sympathetic activity; however, there was a significant positive relationship between both the change in heart rate (slope = 0.131; adjusted R2 = 0.2773; p = 0.002) and the change in mean blood pressure (slope = 0.163; adjusted R2 = 0.3594; p < 0.001) with handgrip volume. An increase in MSNA is observed during rhythmic handgrip despite ranging protocols, populations, and co-interventions. These results suggest exercise is a unique stressor and challenges the understanding of general sympathetic hyperactivity in diseased populations.

Knowledge of task duration affects energetic cost during split-belt adaptation and retention of walking patterns during post-adaptation

Humans continuously adapt locomotor patterns. Whether energetic cost reduction is the primary objective or a by-product of locomotor adaptation is not known. If energetic cost is the primary objective, then manipulating energetic cost will affect the locomotor pattern. Our study aims to determine if information about task duration affects energetic cost and locomotor adaptation during split-belt walking. We hypothesize that information about a longer adaptation duration will result in lower metabolic costs and lower mechanical work. N=52 participants walked for 10 minutes with the belts moving at 1.5 and 0.5 m/s, followed by 6 minutes of walking with both belts at 1.0 m/s. Nineteen participants walked on the split-belt while we provided True information about time remaining every minute (Group T). Nineteen participants received False information that split-belt adaptation duration was around 30 minutes (Group F). Fourteen participants walked on a split-belt with accurate information about task duration, and one update at 5 minutes remaining (Group C). Participants in Groups C and F had a lower rate of change in metabolic cost from baseline (p=0.002) and generated less positive work (p=0.012) than individuals in Group T. Changes in positive work by the fast leg predicted metabolic cost reductions only in Group F (R2=0.18, p=0.040). Participants in Group F showed greater split-belt aftereffects than the C and T groups (p<0.001). We conclude that walking biomechanics are adapted to support an energetic cost reduction when maintaining an energetic reserve is needed, as is the case for Group F, but not Group T.

The study of the association between exercise motivation and cardiorespiratory fitness in young students: a systematic review and meta-analysis

Background

In recent years, many studies have shown that exercise motivation is essential for encouraging students to engage in physical activities. Cardiorespiratory function, which is closely related to cardiorespiratory fitness, plays a crucial supportive role in sports, and its level is usually reflected by cardiorespiratory fitness measurements. This study aims to explore the correlation between exercise motivation and cardiorespiratory fitness in young students, analyze the impact of exercise motivation on cardiorespiratory fitness, and investigate the role of cardiorespiratory fitness in the formation of exercise motivation.

Methods

Following the PRISMA statement, a comprehensive literature search was carried out in six electronic databases from July 1, 2000, to December 1, 2024. The selected studies were strictly quality-assessed, and relevant data were extracted using a standardized form. Then, a meta-analysis was conducted with Stata18 software, along with heterogeneity testing and publication bias assessment.

Results

After screening, 11 studies were included. Eight directly explored the correlation between cardiorespiratory fitness and exercise motivation, while the other four investigated the link between physical activity and exercise motivation, suggesting an association between cardiorespiratory fitness and exercise motivation during physical activity. Pearson correlation analysis (11 studies) and multiple regression analysis (7 studies) were used. By combining effect sizes with a random-effects model, the average correlation coefficient was 0.24 (p < 0.001). The average standardized coefficient of exercise motivation on promoting cardiorespiratory fitness was 0.16 (p < 0.001), and that of cardiorespiratory fitness on enhancing exercise motivation was 0.18 (p < 0.001).

Discussion

The results show a significant positive correlation between exercise motivation and cardiorespiratory fitness in young students, with a moderate positive effect on each other. This provides a theoretical basis for improving young students' cardiorespiratory fitness and exercise motivation. Future research could explore more effective assessment methods to better understand the underlying mechanisms.

Protocol for mouse carotid artery perfusion for in situ brain tissue fixation and parallel unfixed tissue collection

As the study of central control of multiple organ function becomes more prominent, there is an increasing need for the collection of fixed brain and unfixed organs and tissues from the same experimental animal. Here, we present a protocol for performing carotid artery cannulation, organ and tissue collection, in situ brain perfusion and fixation, and brain dissection in mice. We describe steps for cannulating the carotid artery, harvesting the heart and other organs, and perfusing, fixing, and dissecting the brain.

Influence of Primary Neurologic Disease on Cardiovascular Health in Females

Neurocardiology is an interdisciplinary field that examines the complex interactions between the nervous and the cardiovascular systems, exploring how neurological processes, such as autonomic nervous system regulation and brain-heart communication impact heart function and contribute to cardiovascular health and disease. Although much of the focus on cardiovascular health has centered on traditional risk factors, the influence of the nervous system, especially in females, is increasingly recognized as a key determinant of cardiovascular outcomes. This article reviews existing literature on the neurological mechanisms that impact cardiovascular function in females. Specifically, we analyze how primary neurological disorders including cerebrovascular disease, headache disorders, and multiple sclerosis have specific downstream effects on cardiac function. By understanding the complex relationship between neurological and cardiovascular health, this review highlights the need for sex-specific approaches to prevention, diagnosis, and treatment of cardiovascular disease in females, ultimately encouraging the discovery of more effective care strategies and improving health outcomes.

The Effects of Caffeine on Heart Rate and Heart Rate Variability at Rest and During Submaximal Cycling Exercise

The aim of this study was to investigate the effects of caffeine on heart rate and heart rate variability (HRV) at rest and during submaximal exercise. Using a balanced, double-blind, randomized, crossover design, 16 male cyclists (age: 37 ± 9 years; V ˙ O2max: 4.44 ± 0.67 L·min-1) completed three trials in an air-conditioned laboratory. In Trial 1, cyclists completed two incremental cycling tests to establish the V ˙ O2-power output relationship and V ˙ O2max. In trials 2 and 3, cyclists were evaluated for heart rate and HRV at rest, after which they ingested a capsule containing 5 mg·kg-1 of caffeine or placebo. Thirty-five minutes post-supplementation, additional resting heart rate and HRV readings were taken after which cyclists completed a submaximal incremental cycling test (6 min stages) at 40-80% of V ˙ O2max; with HR and HRV measurements taken in the last 5 min of each increment. HRV was determined from the root mean square of successive differences between R-R intervals. There were significant supplement × exercise intensity interactions on heart rate (p = .019) and HRV (p = .023), with post hoc tests on the latter showing that caffeine increased HRV at 40%, 50%, and 60% of V ˙ O2max by 3.6 ± 4.9, 2.6 ± 2.8, and 0.6 ± 1.7 ms, respectively. There was a supplement × time interaction effect on resting HRV (p < .001), but not on heart rate (p = .351). The results of this study support the suggestion that caffeine increases the parasympathetic modulation of heart rate.Clinical trial registration number: NCT05521386.

Factor analysis on the performance of elite male fencing athletes

BACKGROUND

We analyzed how stress and heart rate variability affect the performance of male fencing athletes expected to compete in various international events representing Korea.

METHODS

This study included 72 fencing athletes who participated in training and competition from January 2020 to December 2023. The stress was analyzed using the Sports Competition Anxiety Test (SCAT). Heart rate variability (HRV) was measured using an autonomous neurodiagnostic device (SA-6000). Heart rate variability measurement items were time domain analysis (heart rate, standard deviation of NN interval, and root mean square of the successful differences) and frequency domain analysis (total power, low frequency, and low frequency/high-frequency ratio). All athletes were classified into two categories: victory (high performance) and defeat (low performance) groups in the recent national championships.

RESULTS

In SCAT, there was no significant difference between high and low performance. After comparing HRV, it was found that there is a significant difference in heart rates (P=0.030) and low frequency/high-frequency ratio (P=0.006) between high and low performance. heart rates and low-frequency/high-frequency ratio during the high performance were observed to be higher than during low performance.

CONCLUSIONS

In our study, we found that SCAT does not affect performance, while HRV has been shown to have an impact on performance. These findings can be valuable for coaches and athletes in developing strategies to improve performance results, particularly for elite male fencing athletes.

The role of mechanosignaling in the control of myocardial mass

Regulation of myocardial mass is key for maintaining cardiovascular health. This review highlights the complex and regulatory relationship between mechanosignaling and myocardial mass, influenced by many internal and external factors including hemodynamic and microgravity, respectively. The heart is a dynamic organ constantly adapting to changes in workload (preload and afterload) and mechanical stress exerted on the myocardium, influencing both physiological adaptations and pathological remodeling. Mechanosignaling pathways, such as the mitogen-activated protein kinases (MAPKs) and the phosphoinositide 3-kinases and serine/threonine kinase (PI3K/Akt) pathways, mediate downstream effects on gene expression and play key roles in transducing mechanical cues into biochemical signals, thereby modulating cellular processes, including control of myocardial mass. Dysregulation of these processes can lead to pathological cardiac remodeling, such as hypertrophic cardiomyopathy. Furthermore, recent studies have highlighted the importance of protein quality control mechanisms, such as the ubiquitin-proteasome system, in settings of extreme physiological conditions that alter the heart workload such as pregnancy and microgravity. Overall, this review provides a thorough insight into how mechanical signals are converted into chemical signals to regulate myocardial mass in both healthy and diseased conditions.

Incorporating Virtual Reality Agents During a Dichotic Speech Reception Task: Insights From the Heart

OBJECTIVES

Listening effort is moderated by not only task difficulty, but also success importance. In real communication scenarios, success importance varies based upon the social context. However, in the laboratory, it can be challenging to manipulate social context without compromising experimental control. Outside of hearing sciences, studies have applied virtual reality (VR) to incorporate social context in a controlled and repeatable manner. Several of these studies have demonstrated that social manipulations in VR can reliably elicit changes in cardiovascular measures. Here, we investigated the effect of adding VR agents to a speech reception task, while measuring from the cardiovascular system.

DESIGN

Twenty-eight, normally hearing participants undertook a dichotic speech reception task. Sentences in stationary noise were presented dichotically, that is, different sentences presented simultaneously to each ear. Participants were tasked to either repeat one of the sentences (single-sentence condition) or both of the sentences (dual-sentence condition). The task was conducted under two VR conditions: (1) in the presence of agents, who provided sporadic performance feedback and (2) in the presence of nonagent controls, without any feedback given. Alongside task performance, we quantified changes in cardiovascular measures, relative to pretask baselines: heart rate variability, pre-ejection period, heart rate, and blood pressure. After each condition, participants rated their subjective effort, difficulty, performance, and engagement.

RESULTS

Performance and the subjective perception of performance were lower, while subjective effort and difficulty were higher, in the dual-sentence condition, compared with the single-sentence condition. Heart rate was the only cardiovascular measure that was sensitive to the experimental manipulations. Contrary to our expectations, heart rate increased in the nonagent control conditions, compared with the agent conditions. An exploratory analysis revealed heart rate fluctuations within a trial: heart rate was higher during the first 6 sec of the trial (reflecting the presentence masking noise and the sentence presentation) in the dual-sentence condition, compared with the single-sentence condition.

CONCLUSIONS

This study was the first to incorporate VR agents who provided performance feedback during a dichotic speech reception task. Our results suggest that the VR agents did not increase success importance, which could be attributed to a lack of realism of the agents. We also demonstrated that the cardiovascular response to experimental manipulations may differ depending on the data window selected for analysis.

Modelling neurocardiac physiology and diseases using human pluripotent stem cells: current progress and future prospects

Throughout our lifetime the heart executes cycles of contraction and relaxation to meet the body's ever-changing metabolic needs. This vital function is continuously regulated by the autonomic nervous system. Cardiovascular dysfunction and autonomic dysregulation are also closely associated; however, the degrees of cause and effect are not always readily discernible. Thus, to better understand cardiovascular disorders, it is crucial to develop model systems that can be used to study the neurocardiac interaction in healthy and diseased states. Human pluripotent stem cell (hiPSC) technology offers a unique human-based modelling system that allows for studies of disease effects on the cells of the heart and autonomic neurons as well as of their interaction. In this review, we summarize current understanding of the embryonic development of the autonomic, cardiac and neurocardiac systems, their regulation, as well as recent progress of in vitro modelling systems based on hiPSCs. We further discuss the advantages and limitations of hiPSC-based models in neurocardiac research.

An emotion recognition method based on frequency-domain features of PPG

Objective

This study aims to employ physiological model simulation to systematically analyze the frequency-domain components of PPG signals and extract their key features. The efficacy of these frequency-domain features in effectively distinguishing emotional states will also be investigated.

Methods

A dual windkessel model was employed to analyze PPG signal frequency components and extract distinctive features. Experimental data collection encompassed both physiological (PPG) and psychological measurements, with subsequent analysis involving distribution patterns and statistical testing (U-tests) to examine feature-emotion relationships. The study implemented support vector machine (SVM) classification to evaluate feature effectiveness, complemented by comparative analysis using pulse rate variability (PRV) features, morphological features, and the DEAP dataset.

Results

The results demonstrate significant differentiation in PPG frequency-domain feature responses to arousal and valence variations, achieving classification accuracies of 87.5% and 81.4%, respectively. Validation on the DEAP dataset yielded consistent patterns with accuracies of 73.5% (arousal) and 71.5% (valence). Feature fusion incorporating the proposed frequency-domain features enhanced classification performance, surpassing 90% accuracy.

Conclusion

This study uses physiological modeling to analyze PPG signal frequency components and extract key features. We evaluate their effectiveness in emotion recognition and reveal relationships among physiological parameters, frequency features, and emotional states.

Significance

These findings advance understanding of emotion recognition mechanisms and provide a foundation for future research.

Clevidipine for hypertension treatment during laparoscopic adrenalectomy for pheochromocytoma in a dog

An 11-year-old, 8 kg, castrated male dog was presented for adrenalectomy, after being diagnosed with pheochromocytoma by identification of elevated urine metanephrines. Phenoxybenzamine was started 1 month before surgery (2 mg kg-1, twice daily, orally). Anesthetic premedication was performed with methadone (0.5 mg kg-1) intramuscularly and maropitant (1 mg kg-1) subcutaneously. General anesthesia was induced with intravenous (IV) alfaxalone (1 mg kg-1) and midazolam (0.3 mg kg-1) and maintained with isoflurane in oxygen delivered through a circle breathing system. Dexmedetomidine (0.5 μg kg-1 bolus over 5 minutes, followed by 0.5 μg kg-1 hour-1), magnesium sulfate (50 mg kg-1 hour-1 for the first hour, followed by 15 mg kg-1 hour-1) and lactated Ringer's solution (5 mL kg-1 hour-1) were given IV. Arterial blood pressures were measured invasively. During manipulation of the adrenal gland, systolic and mean arterial blood pressures increased to 240 and 150 mmHg, respectively, and heart rate decreased to 30 beats minute-1. Clevidipine, a calcium channel blocker, was infused IV at 1-2 μg kg-1 minute-1, achieving a reduction in mean arterial blood pressure to between approximately 80 and 85 mmHg, with heart rate between 100 and 120 beats minute-1. Recovery from anesthesia and surgery was uneventful. The dog was discharged from the hospital 3 days after surgery and its clinical status has been stable for 2 years after the procedure. This case report describes the successful treatment of hypertension using clevidipine, a specific arterial vasodilator with fast onset and offset of action and a low incidence of adverse effects.

Transforming Sleep Monitoring: Review of Wearable and Remote Devices Advancing Home Polysomnography and Their Role in Predicting Neurological Disorders

This paper explores the progressive era of sleep monitoring, focusing on wearable and remote devices contributing to advances in the concept of home polysomnography. We begin by exploring the basic physiology of sleep, establishing a theoretical basis for understanding sleep stages and associated changes in physiological variables. The review then moves on to an analysis of specific cutting-edge devices and technologies, with an emphasis on their practical applications, user comfort, and accuracy. Attention is also given to the ability of these devices to predict neurological disorders, particularly Alzheimer's and Parkinson's disease. The paper highlights the integration of hardware innovations, targeted sleep parameters, and partially advanced algorithms, illustrating how these elements converge to provide reliable sleep health information. By bridging the gap between clinical diagnosis and real-world applicability, this review aims to elucidate the role of modern sleep monitoring tools in improving personalised healthcare and proactive disease management.

Improving Fall Classification Accuracy of Multi-Input Models Using Three-Axis Accelerometer and Heart Rate Variability Data

Reduced body movement and weakened musculoskeletal function as a result of aging increase the risk of falls and serious physical injuries requiring medical attention. To solve this problem, a fall prevention algorithm using an acceleration sensor has been developed, and research is being conducted to enable continuous monitoring using a Holter electrocardiograph. In this study, we implemented a multi-input model that can detect and classify movements, including falls, utilizing the baroreflex characteristics of the heart's potential energy changes due to movement, measured with an electrocardiogram with a three-axis acceleration sensor and a Holter electrocardiograph. Patterns were identified from the various movement characteristics of acceleration sensor data using a deep learning model consisting of CNN-LSTM, and heart rate variability (HRV) data were analyzed using a wide learning model to provide additional weight values for fall classification. Finally, a multi-input model using wide and deep learning was proposed to enhance the accuracy of fall classification. The results show that the HRV increased in fall case except in two motion types, while it decreased when standing up from a chair, indicating the application of the baroreflex characteristics reflecting the heart's potential energy. Compared to the classification model using conventional HRV and ACC, a higher accuracy was achieved in the multi-input model using ACC-HRV data, and a precision, recall, and F1 score of 0.91 was measured, indicating improved performance. This is expected to have a positive impact on fall prevention by improving the accuracy of fall classification in the elderly for 15 different movements.

PINNing cerebral blood flow: analysis of perfusion MRI in infants using physics-informed neural networks

Arterial spin labelling (ASL) magnetic resonance imaging (MRI) enables cerebral perfusion measurement, which is crucial in detecting and managing neurological issues in infants born prematurely or after perinatal complications. However, cerebral blood flow (CBF) estimation in infants using ASL remains challenging due to the complex interplay of network physiology, involving dynamic interactions between cardiac output and cerebral perfusion, as well as issues with parameter uncertainty and data noise. We propose a new spatial uncertainty-based physics-informed neural network (PINN), SUPINN, to estimate CBF and other parameters from infant ASL data. SUPINN employs a multi-branch architecture to concurrently estimate regional and global model parameters across multiple voxels. It computes regional spatial uncertainties to weigh the signal. SUPINN can reliably estimate CBF (relative error - 0.3 ± 71.7 ), bolus arrival time (AT) ( 30.5 ± 257.8 ) , and blood longitudinal relaxation time ( T 1 b ) (-4.4 ± 28.9), surpassing parameter estimates performed using least squares or standard PINNs. Furthermore, SUPINN produces physiologically plausible spatially smooth CBF and AT maps. Our study demonstrates the successful modification of PINNs for accurate multi-parameter perfusion estimation from noisy and limited ASL data in infants. Frameworks like SUPINN have the potential to advance our understanding of the complex cardio-brain network physiology, aiding in the detection and management of diseases. Source code is provided at: https://github.com/cgalaz01/supinn.

Recent Issues in the Development and Application of Targeted Therapies with Respect to Individual Animal Variability

This literature review explores the impact of molecular, genetic, and environmental factors on the efficacy of targeted therapies in veterinary medicine. Relevant studies were identified through systematic searches of PubMed, Web of Science, Scopus, and ScienceDirect using keywords such as "species-specific treatment strategies", "signalling pathways", "epigenetic and paragenetic influences", "targeted therapies", "veterinary medicine", "genetic variation", and "free radicals and oxidative stress". Inclusion criteria included studies focusing on species-specific therapeutic responses, genetic influences, and oxidative stress. To ensure that only the most recent and relevant evidence was included, only peer-reviewed publications from the last two decades were considered. Each study selected for analysis was critically appraised, with a particular emphasis on methodological quality, experimental design, and scientific contribution to the understanding of how environmental and biological factors influence therapeutic outcomes. A special emphasis was placed on studies that used a comparative, cross-species approach to assess variability in therapeutic responses and potential adverse effects. The review synthesises evidence on the role of epigenetic and paragenetic factors and highlights the importance of cross-species studies to understand how environmental and biological factors influence treatment outcomes. By highlighting genetic variation, oxidative stress, and individual species differences, the review argues for personalised and species-specific therapeutic approaches. The review emphasises that such an approach would improve veterinary care and inform future research aimed at optimising targeted therapies, ultimately leading to better animal health and treatment efficacy. A key contribution of the review is its emphasis on the need for more personalised treatment protocols that take into account individual genetic profiles and environmental factors; it also calls for a greater integration of cross-species studies.

Exploring Resting Sinus Tachycardia in Cancer Care: A Comprehensive Review

Resting sinus tachycardia is frequently encountered in cancer patients. It affects a wide variety of cancer patients and is associated with distressing symptoms. Cancer-associated resting sinus tachycardia varies in its underlying mechanism. It can stem from the tumor burden or the side effects of chemotherapy/radiotherapy, or it can be secondary to paraneoplastic syndrome or the sequalae of cancer itself (infection, anemia, thrombosis, etc.). The clinical significance of resting sinus tachycardia extends beyond mere symptomatology, as it can potentially indicate severe complications which may facilitate or exacerbate a new or underlying cardiovascular dysfunction. Therefore, this necessitates thorough diagnostic tools to discern the underlying cause and tailor appropriate management strategies, whether pharmacological, non-pharmacological, or conservative. While resting sinus tachycardia has been extensively investigated in the context of cardiovascular disease, its underlying etiology, clinical implication, prognostic value, and treatment options remain vague in the context of cancer. This review aims to explore the topic of resting sinus tachycardia in cancer patients through delving deeper into its underlying mechanism, presenting the current evidence on its effect on cancer-independent cardiovascular and all-cause mortality, as well as providing some insight into the currently available treatment options. It will also propose therapeutic interventions and strategies aimed at optimizing cancer patient care. Lastly, it will highlight research gaps which need to be addressed further, as future research is needed to refine the diagnostic criteria, develop targeted therapies, find alternative cardioprotective/cardio-neutral chemotherapy options, and establish evidence-based guidelines to improve outcomes in this vulnerable patient population.

Running in the heat similarly reduces lipid oxidation and peak oxygen consumption in trained runners and inactive individuals

This study compared oxygen consumption and substrate oxidation while exercising in hot and temperate conditions in individuals with different physical activity statuses (i.e., inactive individuals vs. trained runners). Ten inactive individuals (IA: 26 ± 6 yr; 79.1 ± 14.1 kg; 40.7 ± 5.1 mL·kg-1·min-1) and 10 trained runners (TR: 25 ± 6 yr; 69.5 ± 9.1 kg; 63.1 ± 5.1 mL·kg-1·min-1) completed two incremental exercise tests (4-min stages) until exhaustion in temperate (TEMP: 18.7 ± 0.1°C; 43.2 ± 4.1% relative humidity) and hot (HOT: 34.4 ± 0.2°C and 42.6 ± 1.6% relative humidity) conditions. Expired gas and blood lactate concentrations were measured at the end of each stage. Peak oxygen consumption similarly decreased in HOT compared with TEMP for IA and TR [-13.2 ± 4.5% vs. -15.2 ± 7%; P = 0.571; effect size (ES) = 0.25]. In HOT compared with TEMP, lipid oxidation, from 30% to 70% of peak oxygen consumption (V̇o2peak), was reduced for both groups (IA: P = 0.023, ES = 0.43; TR: P < 0.001, ES = 0.72), whereas carbohydrate oxidation was increased for TR (P = 0.011; ES = 0.45) but not for IA (P = 0.268; ES = 0.21). Core temperature was different between conditions for TR (higher in HOT, P = 0.017; ES = 0.66) but not for IA (P = 0.901; ES = 0.25). Despite reduced physiological capacities in IA, both populations demonstrated reductions in lipid utilization and peak oxygen consumption in hot compared with temperate conditions. However, the increased carbohydrate oxidation in HOT for TR was not observed in IA, potentially explained by lower thermal strain. NEW & NOTEWORTHY This study shows that lipid oxidation and oxygen consumption are similarly affected by heat exposure in trained runners and inactive individuals. Carbohydrate oxidation and core temperature are greater in hot conditions in trained runners but not in inactive individuals. A lower metabolic heat production in inactive individuals for a similar relative intensity compared with trained runners could explain these differences in core temperature.

Tributyl phosphate inhibits neurogenesis and motor functions during embryonic development in zebrafish

Tributyl phosphate (TBP), an organophosphate ester (OPE), is heavily used as a solvent in chemical industries, a plasticizer, and to extract radioactive molecules. Thus, widespread uses of TBP in industrialized countries led to the release of TBP and its metabolites, dibutyl phosphate (DBP) and monobutyl phosphate (MBP), in the environment and were detected in human samples. Accumulating these OPEs over time in humans and aquatic animals may develop toxicological effects. The reports also say TBP passes through the mother-fetal transmission route and may affect embryonic development. However, the impact of TBP and its metabolites on vertebrate development has been poorly studied. Ex-utero development, high fecundity, and optical transparency make the zebrafish a preferred model for toxicological evaluation. Thus, we aim to explore the toxic effects of TBP and its metabolites on aquatic animals using zebrafish as a model organism. Embryos in the chorion were incubated in 10-60 µM test chemicals from 6 to 48 h post fertilization (hpf), and analyzed the adverse effects on embryos. Our study found that 10-20 µM TBP inhibits neural growth, resulting in decreased spontaneous movement frequency and locomotive behavior without altering the overall embryonic growth and muscle functions. In contrast, DBP-treated embryos showed increased spontaneous movement frequency without changing the motor neuron growth and locomotive behavior. Further, in higher concentrations, TBP is teratogenic, and DBP is lethal to the embryos. Altogether, we found that TBP inhibits neurogenesis and motor behavior; however, its metabolite DBP is neuroexcitatory in zebrafish embryos.

Stretching, isometrics, and aerobic exercise for decreasing blood pressure post-exercise: a randomized crossover study

We compared stretching, isometrics, and aerobic exercise for effectiveness in decreasing blood pressure post-exercise. Using a randomized crossover design, 5 males and 4 females (21.3 years; normotensive) participated in four 30 min sessions on separate days: static stretching (30 s stretches, major muscle groups), isometric exercise, aerobic cycling (75% VO2peak), and control (rest), with blood pressure and heart rate measured before exercise (or rest) and for 60 min post-exercise (or rest). Aerobic exercise and stretching decreased post-exercise systolic blood pressure (∼10 mmHg each) (p < 0.05), whereas isometric exercise and the control condition did not significantly decrease post-exercise blood pressure. Stretching is similar to aerobic exercise for reducing blood pressure post-exercise. ClinicalTrials.gov Identifier: NCT06628635.

The Combined Effects of Cold Foot Bath and Lavender Oil Inhalation on Autonomic Variables in Healthy Volunteers: A Randomized Controlled Trial

BACKGROUND AND AIM

An essential function of the autonomic nerve system is to regulate physiological processes and stress responses in the body. Cold foot baths and aromatherapy with lavender oil each influence autonomic functions, but their combined effect in healthy individuals is unknown. The purpose of this study is to look into how autonomic variability in healthy volunteers is affected by both inhaling lavender oil and taking cold foot baths.

METHODS

A total of 60 healthy individuals were randomized to be placed in either the control group (n=30) or the experimental group (n=30) and were instructed to attend a single designated session. The control group underwent a 20-minute cold foot bath, while the experimental group received a 20-minute cold foot bath combined with lavender oil inhalation. Assessments were carried out before, during, and after the interventions.

OUTCOME MEASURES

To evaluate autonomic variables, we monitored galvanic skin response (GSR) and Heart Rate Variability (HRV) using an equivital belt. Furthermore, we measured blood pressure (BP) and mean arterial pressure (MAP) before, during (20 minutes) the intervention, and after a 10-minute resting period; post-intervention measurements were taken.

RESULTS

Repeated measures analysis revealed a significant difference in standard deviation of normal-to-normal intervals (SDNN), pNN50, and heart rate (HR) for time-domain variables (p<0.05), whereas the frequency-domain analysis showed a significant difference over time in LF/HF, LF, and HF (p<0.05). When these were compared between the groups, a significant difference was observed only in LF and HF (p<0.04). Additionally, a statistically significant difference (p<0.001) in diastolic and systolic blood pressure between the groups was noted.

CONCLUSION

The combination of a cold foot bath and lavender oil inhalation may modulate autonomic activity, promoting relaxation by vagal balance in healthy individuals.

Early Prognostic Instrumental and Laboratory Biomarkers in Post-MI

BACKGROUND

Post-myocardial infarction (MI) changes have been frequently reported in the literature and are associated with determining the prognosis.

AIMS

The aim of this study is to find a prognosis marker for the favorability of determination of the medium-term outcomes in patients with acute MI.

OBJECTIVES

MI patients' prognosis is poorly understood and requires further elaboration.

MATERIALS AND METHODS

A single center, cross-sectional cohort study involved 211 patients' medical history with acute MI, for the period 2014-2019, had been evaluated retrospectively for 76 parameters. The data was collected from the Republic Rehabilitation Mordovian Hospital. The described measurement units were used in the local laboratories to describe the values. The descriptive values were expressed in the mean average and standard deviation. For statistical analysis, descriptive statistics, t-test independent by groups and dependent by numerical variables for repeated analysis for the same patients, multinomial logistic regression, Pearson's correlation coefficient, ROC analysis, and for clarification purposes, diagrams and bar figures were used. For performing the statistical analysis, the SPSS program, version 28 was used.

RESULTS

Descriptive statistics showed a proportion of men to females 7:3. The mean age of the MI patients was 61.50 years (Std. Dev. ± 10.68), and the mean height of the sample was 171.00 cm (Std. Dev. ± 7.20). The mean body weight of the sample is 83.62 kg (Std. Dev. ± 12.35), and the body mass index (BMI) is 29.02 kg/m2 (Std. Dev. ± 5.07). The total hospitalization days are 14.79 (Std. Dev. ± 3.41). The mean heart rate (HR) beat per minute (bpm) was 79.03 (Std. Dev. ± 15.63), and the mean blood pressure was 138.53/84.09 mmHg (Std. Dev. ± 28.66/12.79). On the complete blood count (CBC), the mean level of the hemoglobin (Hb) 136.33 g/l (Std. Dev. ± 15.29), the mean level of the leukocytes (WBC) 8.76 /μl (Std. Dev. ± 2.77), the mean level of the red blood cells (RBC) 4.55 /μl (Std. Dev. ± 0.52), the mean level of the relative value of the lymphocytes 24.46 % (Std. Dev. ± 9.015), and the mean level of the thrombocytes 207.87 /μl (Std. Dev. ± 64.035). The mean erythrocytes segmentation rate (ESR) is 18.99 mm/hr (Std. Dev. ± 12.16). The regression analysis demonstrated that the dependent variable, complication, in particular, pericarditis, and the independent factor, concomitant disease, in particular, chronic heart failure, has a significant regression coefficient of 29.101 at p <0.05. Furthermore, the dependent variable, complication, in particular, pneumonitis, and the independent factor, concomitant disease, particularly, arrhythmia, have a significant regression coefficient of 21.937 at p <0.05.

CONCLUSION

An elevated level of CPK-MB/LDH/Troponin I is linked to the development of arrhythmia. Patients with other medical conditions experience high diastolic blood pressure and an enlargement of the right ventricle. The early complication observed after MI is the formation of a left ventricular aneurysm. Complications arise due to low levels of potassium and calcium. Chronic Kidney Disease (CKD) contributes to the End-Diastolic Size (EDS) of the Left Ventricle (LV), Troponin I, and creatine phosphokinase-MB (CPK-MB). Advanced CKD patients have a hypertrophic left ventricle and persistently elevated post-myocardial Infarction (MI) cardiac biomarkers (CPKMB/ LDH/Troponin I) due to impaired kidney detoxification. Therefore, prolonged elevation of MI biomarkers can be an indicative of severe MI or kidney function impairment due to the chronic mild elevation in the MI biomarkers. Pericarditis development is related to the pre-existence of chronic heart failure. Moreover, pneumonitis development is related to the pre-existence of arrhythmia. Others: Hypertensive patients do not exhibit a significant increase in calcium levels, indicating that it is not a reliable biomarker in this patient population. Additionally, gender plays a crucial role in the development of ischemic heart disease, including myocardial infarction.

The effect of Valeriana officinalis tea on sympathovagal tone and cardiac function in healthy volunteers: A semi-experimental study

Objective

The use of herbal teas can affect some physiological parameters of the body. Valerian has been used as a valuable medicinal plant. There are reports about sedative and sleep-inducing effects of Valeriana officinalis L. (VOT) on the nervous system. But in relation to its possible effect on the autonomic nervous system, the available information is limited. This study aimed to determine the effect of VOT on sympathovagal tone based on heart rate variability indices.

Materials and Methods

In this semi-experimental study, 12 healthy volunteers were enrolled. At first, the participants received 50 ml of water as the control group, and then after the clearance time, they received VOT with a dilution of 50% with the same temperature and volume and were considered the intervention group. Assessment of sympathovagal tone was performed in terms of heart rate variability indices. There were 5 recording steps: baseline, after drinking water, and 5, 20, and 30 minutes after drinking VOT.

Results

The mean±SD of the average heart rate per minute at the five recording steps after VOT was 65.4±15.5, 63.5 ±14.6, 62.7±15.6, 61.8±16.09, and 60.9 15.2, respectively (p<0.05). The average arterial systolic pressure at the five recording steps after VOT was 119.4±7.4, 117.9± 9, 114.3±7.9, 113.8±8.6, and 114±6.5 mmHg, respectively.

Conclusion

A single cup of VOT significantly decreased the heart rate. This effect may be associated with a decrease in sympathetic activity and an increase in parasympathetic activity.

Changes in heart rate variability at rest and during exercise in patients after a stroke: a feasibility study

The aim of this study was to evaluate the feasibility of using a biofeedback-enhanced robotics-assisted tilt table (RATT) to investigate time- and intensity-dependent changes in heart rate variability (HRV) at rest and during heart rate-controlled exercise in patients recovering from a stroke. Twelve patients (age 55.3 years ± 15.6 years, 7 women) completed two separate measurement sessions. The first involved familiarization and system identification to determine parameters of a feedback system for automatic control of heart rate (HR). The second comprised 14 min of rest and 21 min of active exercise during which HR was held constant using feedback control to eliminate cardiovascular drift. HR data were collected using a chest-belt HR sensor, and raw RR intervals were employed for HRV analysis during periods of rest (0-7 min and 7-14 min) and exercise (5-13 min and 13-21 min). A biofeedback-enhanced, robotics-assisted tilt table can be successfully employed to perform heart rate-controlled exercises in patients after a stroke. All HRV metrics were substantially lower during exercise compared to rest. In the rest period, HRV values during 0-7 min were lower than during 7-14 min, in line with a slight HR decrease over the entire rest period. During exercise, HRV values during 5-13 min were higher than during 13-21 min, suggesting a time-dependent HRV decrease. All HRV metrics exhibited intensity- and time-dependent changes: higher HRV at rest and decreasing HRV over time. Understanding these HRV characteristics will support the development of heart rate-controlled exercise regimens and protocols for examining HRV changes during exercise in patients.

The Impact of BMI on Heart Rate During Suspension Laryngoscopy Operation in Patients With Laryngeal Lesions: A Prospective Cohort Study

OBJECTIVES

Suspension laryngoscopy can trigger vagal reflexes, leading to a decrease in heart rate, a phenomenon that is more common in patients with a high body mass index (BMI). This study aims to systematically evaluate the effect of BMI on heart rate during suspension laryngoscopy (SL-HR) in patients with laryngeal lesions.

METHODS

We employed univariate generalized linear regression and stratified analyses to assess the relationship between BMI and changes in SLHR, adjusting for confounders such as age, gender, intubation type, and depth. A generalized additive model with spline smoothing was utilized to evaluate the BMI-HR relationship, with piecewise linear regression to identify specific cutoff points.

RESULTS

We conducted a prospective study of 205 patients who underwent general anesthesia for suspension laryngoscopy. Multivariate linear regression analysis indicated that, after adjusting for covariates, each one-unit increase in BMI was associated with a decrease of 1.04 beats per minute in SL-HR (β = -1.04 [95% CI, -1.85 to -0.23]). Curve fitting revealed a gradual decline in SL-HR with increasing BMI, plateauing at around 60 beats per minute. The decrease in SL-HR became more pronounced as BMI approached 30 kg/m², with further analysis revealing an inflection point at a BMI of 28.8 kg/m², where each additional unit of BMI correlated with a 6.5 beats per minute decrease in heart rate (β = -6.5 [95% CI, -10.1 to -2.8], P < 0.001).

CONCLUSIONS

Patients with high BMI are more prone to vagal reflexes during suspension laryngoscopy, resulting in significant reductions in heart rate, especially when BMI exceeds 28.8 kg/m². Therefore, close monitoring of heart rate changes is crucial in this patient demographic, along with considering prophylactic anticholinergic agents to mitigate vagal reflex effects.

Proteomics Reveals Divergent Cardiac Inflammatory and Metabolic Responses After Inhalation of Ambient Particulate Matter With or Without Ozone

Inhalation of ambient particulate matter (PM) and ozone (O3) has been associated with increased cardiovascular morbidity and mortality. However, the interactive effects of PM and O3 on cardiac dysfunction and disease have not been thoroughly examined, especially at a proteomic level. The purpose of this study was to identify and compare proteome changes in spontaneously hypertensive (SH) rats co-exposed to concentrated ambient particulates (CAPs) and O3, with a focus on investigating inflammatory and metabolic pathways, which are the two major ones implicated in the pathophysiology of cardiac dysfunction. For this, we measured and compared changes in expression status of 9 critical pro- and anti-inflammatory cytokines using multiplexed ELISA and 450 metabolic proteins involved in ATP production, oxidative phosphorylation, cytoskeletal organization, and stress response using two-dimensional electrophoresis (2-DE) and mass spectrometry (MS) in cardiac tissue of SH rats exposed to CAPs alone, O3 alone, and CAPs + O3. Proteomic expression profiling revealed that CAPs alone, O3 alone, and CAPs + O3 differentially altered protein expression patterns, and utilized divergent mechanisms to affect inflammatory and metabolic pathways and responses. Ingenuity Pathway Analysis (IPA) of the proteomic data demonstrated that the metabolic protein network centered by gap junction alpha-1 protein (GJA 1) was interconnected with the inflammatory cytokine network centered by nuclear factor kappa beta (NF-kB) potentially suggesting inflammation-induced alterations in metabolic pathways, or vice versa, collectively contributing to the development of cardiac dysfunction in response to CAPs and O3 exposure. These findings may enhance understanding of the pathophysiology of cardiac dysfunction induced by air pollution and provide testable hypotheses regarding mechanisms of action.

Physiological effects of hand grip and cold pressor tests in young Saudi adults

The risk of cardiovascular disease differs among various ethnic groups, highlighting disparities in cardiovascular health among different populations. While multiple studies from other countries have looked at changes in physiological parameters during autonomic function tests like isometric handgrip and cold pressor tests, no correlational research has been done in Saudi Arabia. This lacuna underscores the importance of examining the relationship between cardiorespiratory parameters in young Saudi Arabian individuals during these tests. This study aimed to determine the correlation between the isometric handgrip and cold pressor tests and physiological parameters in healthy young Saudi Arabian college students. A single-arm interventional study was conducted with a cohort of 65 healthy young adult Saudi college students, including male and female participants. A point estimate was calculated with a 95% confidence level. Physiological parameters were analyzed and compared at rest and during isometric handgrip and cold pressor tests. The study involved participants with an average age of 21.12 ± 1.02, predominantly male students. A significant impact was observed only in respiratory rate (P = 0.007) during the isometric handgrip and cold pressor tests. In contrast, blood pressure parameters and arterial oxygen saturation values showed no statistical significance during both tests. This sheds light on their autonomic responses to physiological stressors and contributes to our understanding of cardiovascular health across diverse populations, guiding future interventions for global improvements in cardiorespiratory outcomes.

Iodine-123 Metaiodobenzylguanidine (I-123 MIBG) in Clinical Applications: A Comprehensive Review

Iodine-123 metaiodobenzylguanidine (I-123 MIBG) is a crucial radiopharmaceutical widely used in nuclear medicine for its diagnostic capabilities in both cardiology and oncology. This review aims to present a comprehensive evaluation of the clinical applications of I-123 MIBG, focusing on its use in diagnosing and managing various diseases. In cardiology, I-123 MIBG has proven invaluable in assessing cardiac sympathetic innervation, particularly in patients with heart failure, where it provides prognostic information that guides treatment strategies. In oncology, I-123 MIBG is primarily utilized for imaging neuroendocrine tumors, such as neuroblastoma and pheochromocytoma, where it offers high specificity and sensitivity in the detection of adrenergic tissue. Additionally, its role in neurology, specifically in differentiating between Parkinson's disease, dementia, and Lewy body dementia, has become increasingly significant due to its ability to identify postganglionic sympathetic dysfunction. Despite its established clinical utility, the use of I-123 MIBG is not without limitations, including variability in imaging protocols and interpretation challenges. This review will explore these issues and discuss emerging alternatives, while also highlighting areas where I-123 MIBG continues to be a gold standard. By synthesizing the current research, this article aims to provide a clear understanding of the strengths, limitations, and prospects of I-123 MIBG in clinical practice.

Remodeling of the Intracardiac Ganglia During the Development of Cardiovascular Autonomic Dysfunction in Type 2 Diabetes: Molecular Mechanisms and Therapeutics

Type 2 diabetes mellitus (T2DM) is one of the most significant health issues worldwide, with associated healthcare costs estimated to surpass USD 1054 billion by 2045. The leading cause of death in T2DM patients is the development of cardiovascular disease (CVD). In the early stages of T2DM, patients develop cardiovascular autonomic dysfunction due to the withdrawal of cardiac parasympathetic activity. Diminished cardiac parasympathetic tone can lead to cardiac arrhythmia-related sudden cardiac death, which accounts for 50% of CVD-related deaths in T2DM patients. Regulation of cardiovascular parasympathetic activity is integrated by neural circuitry at multiple levels including afferent, central, and efferent components. Efferent control of cardiac parasympathetic autonomic tone is mediated through the activity of preganglionic parasympathetic neurons located in the cardiac extensions of the vagus nerve that signals to postganglionic parasympathetic neurons located in the intracardiac ganglia (ICG) on the heart. Postganglionic parasympathetic neurons exert local control on the heart, independent of higher brain centers, through the release of neurotransmitters, such as acetylcholine. Structural and functional alterations in cardiac parasympathetic postganglionic neurons contribute to the withdrawal of cardiac parasympathetic tone, resulting in arrhythmogenesis and sudden cardiac death. This review provides an overview of the remodeling of parasympathetic postganglionic neurons in the ICG, and potential mechanisms contributing to the withdrawal of cardiac parasympathetic tone, ventricular arrhythmogenesis, and sudden cardiac death in T2DM. Improving cardiac parasympathetic tone could be a therapeutic avenue to reduce malignant ventricular arrhythmia and sudden cardiac death, increasing both the lifespan and improving quality of life of T2DM patients.

Association of heart rate variability with cardiorespiratory fitness and muscle strength in patients after hospitalization for COVID-19: An analytical cross-sectional study

INTRODUCTION

Patients with a moderate to severe clinical condition of COVID-19 who need hospitalization may have dysfunction in Cardiac Autonomic Control (CAC) and functional capacity.

OBJECTIVE

To assess the association of HRV with cardiorespiratory fitness and respiratory and peripheral muscle strength in patients after hospitalization for COVID-19.

METHOD

Cross-sectional study with individuals > 18-years old, post-hospitalization for COVID-19, with a positive RT-PCR test. Data on clinical condition and hospital admission were collected, and parameters of respiratory and peripheral muscle strength and functional capacity were evaluated with the 6-Minute Walk Test (6MWT). CAC was assessed by analyzing (Heart Rate Variability) HRV in the time (SDNN, RMSSD) and frequency domains (HF, LF, HF/LF ratio). Pearson correlation was performed between HRV measures and functional parameters.

RESULTS

The results showed low HRV in study participants, with positive correlations between 6MWT and RMSSD and between SDNN and HF power and negative correlations between Heart Rate and the LF/HF ratio. On the other hand, respiratory and peripheral muscle strength correlated positively with parameters that represent sympathetic nervous system expression (LF nu and LF power) and negatively with the LF/HF ratio. However, changes in HRV parameters were not associated with disease severity.

CONCLUSION

The dysautonomia of COVID-19 patients was correlated with functional sequelae, though not associated with disease severity parameters. There was low HRV, with low vagal expression, and imbalance in sympathetic/parasympathetic modulation in the study group.

Heart regeneration from the whole-organism perspective to single-cell resolution

Cardiac regenerative potential in the animal kingdom displays striking divergence across ontogeny and phylogeny. Here we discuss several fundamental questions in heart regeneration and provide both a holistic view of heart regeneration in the organism as a whole, as well as a single-cell perspective on intercellular communication among diverse cardiac cell populations. We hope to provide valuable insights that advance our understanding of organ regeneration and future therapeutic strategies.

Autonomic Dysregulation in Pulmonary Hypertension: Role of Physical Exercise

Pulmonary hypertension (PH) is a rare and severe condition characterized by increased pressure in the pulmonary circulation, often resulting in right ventricular failure and death. The autonomic nervous system (ANS) plays a crucial role in the cardiovascular and pulmonary controls. Dysfunction of ANS has been implicated in the pathogenesis of cardiopulmonary diseases. Conversely, dysfunctions in ANS can arise from these diseases, impacting cardiac and pulmonary autonomic functions and contributing to disease progression. The complex interaction between ANS dysfunction and PH plays a crucial role in the disease progression, making it essential to explore interventions that modulate ANS, such as physical exercise, to improve the treatment and prognosis of patients with PH. This review addresses autonomic dysfunctions found in PH and their implications for the cardiopulmonary system. Furthermore, we discuss how physical exercise, a significant modulator of ANS, may contribute to the prognosis of PH. Drawing from evidence of aerobic and resistance exercise training in patients and experimental models of PH, potential cardiovascular benefits of exercise are presented. Finally, we highlight emerging therapeutic targets and perspectives to better cope with the complex condition. A comprehensive understanding of the interaction between ANS and PH, coupled with targeted physical exercise interventions, may pave the way for innovative therapeutic strategies and significantly improve the treatment and prognosis of vulnerable patients.

Modelling hemodynamics regulation in rats and dogs to facilitate drugs safety risk assessment

Pharmaceutical companies routinely screen compounds for hemodynamics related safety risk. In vitro secondary pharmacology is initially used to prioritize compounds while in vivo studies are later used to quantify and translate risk to humans. This strategy has shown limitations but could be improved via the incorporation of molecular findings in the animal-based toxicological risk assessment. The aim of this study is to develop a mathematical model for rat and dog species that can integrate secondary pharmacology modulation and therefore facilitate the overall pre-clinical safety translation assessment. Following an extensive literature review, we built two separate models recapitulating known regulation processes in dogs and rats. We describe the resulting models and show that they can reproduce a variety of interventions in both species. We also show that the models can incorporate the mechanisms of action of a pre-defined list of 50 pharmacological mechanisms whose modulation predict results consistent with known pharmacology. In conclusion, a mechanistic model of hemodynamics regulations in rat and dog species has been developed to support mechanism-based safety translation in drug discovery and development.

Remote Monitoring of Sympathovagal Imbalance During Sleep and Its Implications in Cardiovascular Risk Assessment: A Systematic Review

Nocturnal sympathetic overdrive is an early indicator of cardiovascular (CV) disease, emphasizing the importance of reliable remote patient monitoring (RPM) for autonomic function during sleep. To be effective, RPM systems must be accurate, non-intrusive, and cost-effective. This review evaluates non-invasive technologies, metrics, and algorithms for tracking nocturnal autonomic nervous system (ANS) activity, assessing their CV relevance and feasibility for integration into RPM systems. A systematic search identified 18 relevant studies from an initial pool of 169 publications, with data extracted on study design, population characteristics, technology types, and CV implications. Modalities reviewed include electrodes (e.g., electroencephalography (EEG), electrocardiography (ECG), polysomnography (PSG)), optical sensors (e.g., photoplethysmography (PPG), peripheral arterial tone (PAT)), ballistocardiography (BCG), cameras, radars, and accelerometers. Heart rate variability (HRV) and blood pressure (BP) emerged as the most promising metrics for RPM, offering a comprehensive view of ANS function and vascular health during sleep. While electrodes provide precise HRV data, they remain intrusive, whereas optical sensors such as PPG demonstrate potential for multimodal monitoring, including HRV, SpO2, and estimates of arterial stiffness and BP. Non-intrusive methods like BCG and cameras are promising for heart and respiratory rate estimation, but less suitable for continuous HRV monitoring. In conclusion, HRV and BP are the most viable metrics for RPM, with PPG-based systems offering significant promise for non-intrusive, continuous monitoring of multiple modalities. Further research is needed to enhance accuracy, feasibility, and validation against direct measures of autonomic function, such as microneurography.

From Microbes to Myocardium: A Comprehensive Review of the Impact of the Gut-Brain Axis on Cardiovascular Disease

Cardiovascular diseases (CVDs) remain the leading cause of morbidity and mortality worldwide despite advances in medical research and therapeutics. Emerging evidence suggests a significant role of the gut-brain axis, a complex communication network involving the gut microbiota, central nervous system, and cardiovascular system, in modulating cardiovascular health. The gut microbiota influences systemic inflammation, neurohumoral pathways, and metabolic processes, which are critical in the pathogenesis of CVD. Dysbiosis, or an imbalance in the gut microbiota, has been implicated in various cardiovascular conditions, including hypertension, atherosclerosis, and heart failure. This comprehensive review aims to elucidate the intricate relationship between the gut microbiome, brain, and cardiovascular system, highlighting the mechanisms by which gut-derived signals affect cardiovascular function. Key microbial metabolites, such as short-chain fatty acids (SCFAs) and trimethylamine N-oxide (TMAO), and their impact on vascular health and blood pressure regulation are discussed. Furthermore, the review explores potential therapeutic strategies targeting the gut-brain axis, including probiotics, prebiotics, dietary modifications, and pharmacological interventions, to improve cardiovascular outcomes. Despite promising findings, the field faces challenges such as individual variability in microbiome composition, complexities in gut-brain interactions, and the need for robust clinical trials to establish causality. Addressing these challenges through interdisciplinary research could pave the way for innovative, personalized therapeutic approaches. This review provides a comprehensive understanding of the gut-brain-cardiovascular axis, underscoring its potential as a novel target for preventing and treating CVD.

Effects of an 8-week pre-season targeted training on sprinting performance, agility and lower limb muscular asymmetries in elite soccer players

The purpose of this study was to determine the effects of an 8 week targeted training program on speed, agility, and muscle asymmetries in soccer players. 32 elite soccer players were recruited for the study. Their age, body mass, and body height were 25.8 ± 7.3 years, 77.4 ± 11.1 kg, and 177.5 ± 9.8 cm, respectively. After the warm-up, participants performed two maximum 30 m sprints with a 5-minute rest interval between trials. After the linear sprint test, performed two repetitions of the COD randomized ZigZag test. The tests were performed at the beginning and at the end of the pre-season, which lasted for 8 weeks. EMG was measured bilaterally from the quadriceps, hamstrings, and gluteal muscles with shorts made of knitted fabric similar to elastic clothes. Athletes in the experimental group performed sport-specific targeted strength training based on movement patterns 4 times per week (Monday, Tuesday, Thursday, and Friday). The training included 6 bodyweight exercises (Bird Dog, Single-Leg Glute Bridge, Dead Bug, Side Plank, Reverse Lunge, and Clamshell), performed unilaterally in 5 sets of 10 repetitions of each exercise. The load progression included an additional set in each successive week of the experiment. The data analysis showed significant improvement in 5 m and 30 m sprints after applying the 8-week targeted training protocol. A statistically significant improvement in performance was also observed after the 8-week training period in case of COD, while the speed deficit also decreased significantly. The greatest improvements were observed during the COD test. As a result of repeated COD training over a period of 8 weeks, its technique was improved. Implementation of training methods, which target specific aspects of soccer in the pre-season training routines can improve key motor abilities for that sports discipline. A comprehensive training approach including speed, agility, and resistance training based on specific movement patterns should be applied by strength and conditioning practitioners in soccer teams to achieve peak physical performance and reduce injury risk due to the partial elimination of muscular asymmetries.