Heart rate variability as predictive factor for sudden cardiac death

Heart rate fluctuation predicts mortality in critically ill patients in the intensive care unit: a retrospective cohort study

Background

To evaluate the association between heart rate (HR) fluctuation and mortality in critically ill patients in the intensive care unit (ICU).

Methods

A total of 27,814 patients were enrolled from the Medical Information Mart for Intensive Care database and were divided into 3 groups: low HR fluctuation [<25 beats per minute (bpm)], control (25-34 bpm), and high HR fluctuation (≥35 bpm), based on the initial 24-hour HR fluctuation (calculated as the maximum HR minus minimum HR). Multivariate Cox regression and restricted cubic spline models were used.

Results

Compared to the control group, higher risk of 28-day and 1-year mortality remained significant in an adjusted model, with hazard ratios of 1.210 [95% confidence interval (CI), 1.103-1.327] and 1.150 (95% CI, 1.078-1.227), respectively, in the high HR fluctuation group, as well as hazard ratios of 1.130 (95% CI, 1.035-1.232) and 1.087 (95% CI, 1.022-1.157), respectively, in the low HR fluctuation group. Restricted cubic splines showed a U-type curve, with the lowest risk of mortality at an HR fluctuation of 30 bpm.

Conclusions

This retrospective cohort study revealed that both high and low HR fluctuation correlated with increased mortality in critically ill ICU patients, providing new insights for optimizing HR control strategies.

Effects of a Plastic-Free Lifestyle on Urinary Bisphenol A Levels in School-Aged Children of Southern Italy: A Pilot Study

Bisphenol A (BPA) is an endocrine disruptor (ED) frequently used in food packaging. BPA is used as a monomer in the manufacture of some food packaging. This study aimed to evaluate the urinary BPA concentration in an Italian pediatric cohort, testing the levels of this ED over a period of 6 months, evaluating the effects of a diet regimen with a reduction of Plastic Food Packaging (PFP). One hundred thirty Italian children were enrolled and divided into two groups "School Canteen" and "No School Canteen." The first group consumed one meal at school using a plastic-free service for 5 days/weeks, while the other group did not modify their normal meal-time habits. The BPA levels were tested in urine samples at three time points: T0, is the time before the application of the plastic-free regimen diet; T3, 3 months later; and T6, 6 months later. A reduction of urine BPA levels was detected in the "School Canteen" group. In particular, the reduction was significant analyzing both the intra (among the three testing times) group and inter (between "School Canteen" and "No School Canteen") group variability. Our results show the effects of a diet regimen with a reduction of PFP, demonstrating a connection between urinary BPA levels and food packaging.

MONITORIA: The start of a new era of ambulatory heart failure monitoring? Part I - Theoretical Rationale

Heart failure (HF) is a multifactorial chronic syndrome with progressive increasing incidence causing a huge financial burden worldwide. Remote monitoring should, in theory, improve HF management, but given increasing morbidity and mortality, a question remains: are we monitoring it properly? Device-based home monitoring enables objective and continuous measurement of vital variables and non-invasive devices should be first choice for elderly patients. There is no shortage of literature on the subject, however, most studies were designed to monitor a single variable or class of variables that were not properly assembled and, to the best of our knowledge, there are no large randomized studies about their impact on HF patient management. To overcome this problem, we carefully selected the most critical possible HF decompensating factors to design MONITORIA, a non-invasive device for comprehensive HF home monitoring. MONITORIA stands for MOnitoring Non-Invasively To Overcome mortality Rates of heart Insufficiency on Ambulatory, and in this paper, which is part I of a series of three articles, we discuss the theoretical basis for its design. MONITORIA and its inherent follow-up strategy will optimize HF patient care as it is a promising device, which will essentially adapt innovation not to the disease but rather to the patients.

Biological and Psychological Stress Correlates Are Linked to Glucose Metabolism, Obesity, and Gender Roles in Women

OBJECTIVES

Psychological stress affects central as well as peripheral metabolism and hormone trafficking via the hypothalamic-pituitary-adrenal axis. Stress thereby plays a decisive role in the etiology and progression of overweight and obesity, leading to several chronic diseases, such as diabetes, and mental health disorders. The interplay of biological and psychometric correlates of stress, anthropometric, immunological, and metabolic parameters and psychosocial factors such as gender roles, however, remains poorly understood.

METHODS

In this exploratory study, 43 healthy women were assessed for glucose metabolism by an oral glucose tolerance test and computation of functional parameters for insulin secretion, sensitivity, and resistance. Further, the fatty liver index (FLI) and anthropometric parameters body mass index (BMI), waist-to-hip ratio, body fat, and lean mass were assessed. Psychological stress assessment included the "Brief Symptom Inventory" (BSI), the "Burnout Dimensions Inventory" (BODI), and Perceived Stress Scale (PSS). Biological stress response was evaluated with heart rate variability and cortisol levels. Finally, gender role self-identification was assessed with the "Bem Sex-Role Inventory" (BSRI). Generalized linear models were computed for exploratory association with psychometric outcome. Uncorrected p values are reported.

RESULTS

Burnout and PSS scores were associated with insulin secretion, sputum cortisol, thyroid-stimulating hormone, anthropometric measures, and gender role. BSI ratings for psychiatric symptom dimensions were associated with insulin resistance, sex hormones, anthropometric measures, and gender role. Female self-identification was associated with higher BMI as well as body fat and a higher FLI.

CONCLUSIONS

Considering the increased risk of unfavorable metabolic, cardiovascular, and also mental health outcome in obese women, a higher BMI in women with predominant female gender self-identification may be relevant for clinical risk assessment. The broad range of interacting biological, psychological, and gender-related parameters calls for an integrative management of both mental and endocrinological health. However, the exploratory nature of the study requires replication in larger samples before definite conclusion can be drawn.

Acute Effects of Resistance Exercise With Blood Flow Restriction in Elderly Women: A Pilot Study

AIM

To compare the acute effects of two resistance exercise sessions with different partial blood flow restrictions (BFR) on hemodynamic parameters and cardiac autonomic modulation in older women with metabolic syndrome.

METHODS

Thirty-nine older women (64.4 ± 4.5 years) were allocated into three groups: BFR0 = resistance exercise (20%, 1 maximum repetition [MR]) + 0% BFR; BFR60 = 20% 1 MR resistance exercise + 60% BFR; and BFR80 = 20% 1MR resistance exercise + 80% BFR.

RESULTS

A reduction of 14 mmHg (BFR60 group) and 13 mmHg (BRF80 group) was observed 48 hr after the first exercise session, while vagal modulation was increased in the BRF60 group after 24 and 48 hr.

CONCLUSION

A low-intensity resistance exercise session with 60% and 80% of BFR resulted in blood pressure (systolic, diastolic, and mean) reduction and positive changes on heart rate variability after 24 h of a RE session.

Locomotion in virtual environments predicts cardiovascular responsiveness to subsequent stressful challenges

Individuals differ in their physiological responsiveness to stressful challenges, and stress potentiates the development of many diseases. Heart rate variability (HRV), a measure of cardiac vagal break, is emerging as a strong index of physiological stress vulnerability. Thus, it is important to develop tools that identify predictive markers of individual differences in HRV responsiveness without exposing subjects to high stress. Here, using machine learning approaches, we show the strong predictive power of high-dimensional locomotor responses during novelty exploration to predict HRV responsiveness during stress exposure. Locomotor responses are collected in two ecologically valid virtual reality scenarios inspired by the animal literature and stress is elicited and measured in a third threatening virtual scenario. Our model's predictions generalize to other stressful challenges and outperforms other stress prediction instruments, such as anxiety questionnaires. Our study paves the way for the development of behavioral digital phenotyping tools for early detection of stress-vulnerable individuals.

Study protocol for a prospective, longitudinal cohort study investigating the medical and psychosocial outcomes of UK combat casualties from the Afghanistan war: the ADVANCE Study

INTRODUCTION

The Afghanistan war (2003-2014) was a unique period in military medicine. Many service personnel survived injuries of a severity that would have been fatal at any other time in history; the long-term health outcomes of such injuries are unknown. The ArmeD SerVices TrAuma and RehabilitatioN OutComE (ADVANCE) study aims to determine the long-term effects on both medical and psychosocial health of servicemen surviving this severe combat related trauma.

METHODS AND ANALYSIS

ADVANCE is a prospective cohort study. 1200 Afghanistan-deployed male UK military personnel and veterans will be recruited and will be studied at 0, 3, 6, 10, 15 and 20 years. Half are personnel who sustained combat trauma; a comparison group of the same size has been frequency matched based on deployment to Afghanistan, age, sex, service, rank and role. Participants undergo a series of physical health tests and questionnaires through which information is collected on cardiovascular disease (CVD), CVD risk factors, musculoskeletal disease, mental health, functional and social outcomes, quality of life, employment and mortality.

ETHICS AND DISSEMINATION

The ADVANCE Study has approval from the Ministry of Defence Research Ethics Committee (protocol no:357/PPE/12) agreed 15 January 2013. Its results will be disseminated through manuscripts in clinical/academic journals and presentations at professional conferences, and through participant and stakeholder communications.

TRIAL REGISTRATION NUMBER

The ADVANCE Study is registered at ISRCTN ID: ISRCTN57285353.

Physiological Monitoring to Enhance Clinical Hypnosis and Psychotherapy

Physiological monitoring provides a useful access into the patient's affective state during hypnotically assisted therapeutic sessions. Physiological monitoring identifies autonomic dysregulation and can also display the process of restoring autonomic regulation via hypnosis and other quieting strategies. Commonly used modalities for physiological monitoring are identified, and clinical illustrations of how psychophysiological monitoring can be used in hypnosis and hypnotically assisted psychotherapy are provided. Clinicians may benefit from including psychophysiological knowledge in hypnosis education. Physiological monitoring may enhance hypnosis interventions for some disorders; however, more research is needed for evaluation of efficacy.

Proarrhythmic electrophysiological and structural remodeling in rheumatoid arthritis

Chronic inflammatory disorders, including rheumatoid arthritis (RA), are associated with a twofold increase in the incidence of sudden cardiac death (SCD) compared with the healthy population. Although this is partly explained by an increased prevalence of coronary artery disease, growing evidence suggests that ischemia alone cannot completely account for the increased risk. The present review explores the mechanisms of cardiac electrophysiological remodeling in response to chronic inflammation in RA. In particular, it focuses on the roles of nonischemic structural remodeling, altered cardiac ionic currents, and autonomic nervous system dysfunction in ventricular arrhythmogenesis and SCD. It also explores whether common genetic elements predispose to both RA and SCD. Finally, it evaluates the potential dual effects of disease-modifying therapy in both diminishing and promoting the risk of ventricular arrhythmias and SCD.

Bayesian Estimation of Correlation between Measures of Blood Pressure Indices, Aerobic Capacity and Resting Heart Rate Variability Using Markov Chain Monte Carlo Simulation and 95% High Density Interval in Female School Teachers

Background: Several explanations regarding the disparity observed in the literature with regard to heart rate variability (HRV) and its association with performance parameters have been proposed: the time of day when the recording was conducted, the condition (i.e., rest, active, post activity) and the mathematical and physiological relationships that could have influenced the results. A notable observation about early studies is that they all followed the frequentist approach to data analyses. Therefore, in an attempt to explain the disparity observed in the literature, the primary purpose of this study was to estimate the association between measures of HRV indices, aerobic performance parameters and blood pressure indices using the Bayesian estimation of correlation on simulated data using Markov Chain Monte Carlo (MCMC) and the equal probability of the 95% high density interval (95% HDI). Methods: The within-subjects with a one-group pretest experimental design was chosen to investigate the relationship between baseline measures of HRV (rest; independent variable), myocardial work (rate–pressure product (RPP)), mean arterial pressure (MAP) and aerobic performance parameters. The study participants were eight local female schoolteachers aged 54.1 ± 6.5 years (mean ± SD), with a body mass of 70.6 ± 11.5 kg and a height of 164.5 ± 6.5 cm. Their HRV data were analyzed in R package, and the Bayesian estimation of correlation was calculated employing the Bayesian hierarchical model that uses MCMC simulation integrated in the JAGS package. Results: The Bayesian estimation of correlation using MCMC simulation reproduced and supported the findings reported regarding norms and the within-HRV-indices associations. The results of the Bayesian estimation showed a possible association (regardless of the strength) between pNN50% and MAP (rho = 0.671; 95% HDI = 0.928–0.004), MeanRR (ms) and RPP (rho = −0.68; 95% HDI = −0.064–−0.935), SDNN (ms) and RPP (rho = 0.672; 95% HDI = 0.918–0.001), LF (ms²) and RPP (rho = 0.733; 95% HDI = 0.935–0.118) and SD2 and RPP (rho = 0.692; 95% HDI = 0.939–0.055). Conclusions: The Bayesian estimation of correlation with 95% HDI on MCMC simulated data is a new technique for data analysis in sport science and seems to provide a more robust approach to allocating credibility through a meaningful mathematical model. However, the 95% HDI found in this study, accompanied by the theoretical explanations regarding the dynamics between the parasympathetic nervous system and the sympathetic nervous system in relation to different recording conditions (supine, reactivation, rest), recording systems, time of day (morning, evening, sleep etc.) and age of participants, suggests that the association between measures of HRV indices and aerobic performance parameters has yet to be explicated.

Age-Related Change in Heart Rate Variability at Resting in Thai Professional Athletes

Background: Although regular exercise is beneficially acknowledged in promoting general health status, the cardiovascular risk of sudden cardiac death in highly training athletes has been reported. Unfortunately, the primary key factor in inducing cardiac problems in athletic populations is still questioned. Objectives: In the present study, we aim to determine factors that could affect the relationship between physical activity level and cardiac autonomic function in the Thai population. Methods: Forty participants were recruited and classified into three groups based on their physical activity level and sport profession, including sedentary men, elite handball players, and professional futsal players. In all participants, we measured predicted maximal oxygen consumption, time- and frequency- domain heart rate variability (HRV) variables at rest. Results: Results demonstrated a positive correlation between time-domain HRV and estimated maximal oxygen consumption, but not with frequency-domain HRV, in which athletes aged lower than 25 years old (18 - 25 years old) had a significantly higher in the standard deviation of normal RR intervals (SDNN) and root mean square of the successive differences (RMSSD) than that in age-matched sedentary subjects. Interestingly, athletes aged above 25 years old (25 - 32 years old) had lower SDNN and RMSSD with higher low frequency/high-frequency ratio than those athletes aged under 25. Since all athletes aged above 25 years old were world-class national futsal players, stress due to the competitive level might be another factor influencing cardiac autonomic activity in athletes. Conclusions: In conclusion, the study suggested the importance of age and stress exposure on cardiac autonomic regulation in elite athletes. The observed correlation also reinforced HRV as a potential marker in detecting abnormal changes in cardiac health even in an athletic population.

Fluid Loss during Exercise-Heat Stress Reduces Cardiac Vagal Autonomic Modulation

PURPOSE

Sweat-induced fluid loss during prolonged exercise-heat stress can compromise cardiovascular and thermoregulatory function, although its effects on cardiac autonomic modulation remain unclear. We therefore examined heart rate variability (HRV) and recovery (HRRec), as surrogates of cardiac autonomic modulation, during and after prolonged exercise in the heat with and without fluid replacement.

METHODS

Eleven young and healthy men performed 90 min of semi-recumbent cycling in dry heat (40°C; 20% relative humidity) at a fixed rate of metabolic heat production (600 W; ~46% V˙O2peak) followed by 40-min resting recovery without fluid replacement (No-FR; ~3.4% reduction in body mass). On a separate day, participants completed the same protocol with fluid replacement (FR; 500-700 mL timed boluses) to offset sweat losses. Esophageal temperature and ECG were recorded throughout, with measurements analyzed over 10-min averaged epochs during baseline, each 30-min interval during exercise and 20-min interval during recovery.

RESULTS

Esophageal temperature and heart rate were elevated in No-FR relative to FR throughout exercise (all P ≤ 0.02). The HRV indices reflecting vagal influence of heart rate including the cardiac vagal index (CVI = log10[16 × SD1 × SD2]) and root-mean-square of successive differences were attenuated throughout exercise relative to baseline in both conditions (all P < 0.05), with the magnitude of the reduction greater in the No-FR condition (all P < 0.05). Further, sample entropy was reduced throughout all time points measured during exercise in the No-FR relative to FR condition (all P ≤ 0.03).

CONCLUSIONS

Our unique observations indicate that while prolonged exercise heat stress attenuates the vagal influence and complexity of cardiac rhythms, that reduction is further exacerbated by fluid loss, highlighting the importance of fluid replacement in such conditions.

Heart rate variability in older workers during work under the Threshold Limit Values for heat exposure

BACKGROUND

The Threshold Limit Values (TLV) of the American Conference of Governmental and Industrial Hygienists indicate the levels of heat stress that all workers may be repeatedly exposed to without adverse health effects. In this study, we evaluated heart rate variability (HRV) during moderate-to-heavy work performed continuously or according to different TLV work-rest (WR) allocations in healthy physically active older workers.

METHODS

Nine healthy older (58 ± 5 years) males performed three different 120-minute conditions in accordance with TLV guidelines for moderate-to-heavy intensity work (360 W fixed rate of heat production) in different wet-bulb globe temperatures (WBGT): continuous cycling at 28°C WBGT (CON), as well as intermitted work performed at WR of 3:1 in 29°C WBGT (WR3:1), and at WR of 1:1 at 30°C (WR1:1). Rectal temperature and HRV (3-lead electrocardiogram [ECG]) were assessed throughout.

RESULTS

Coefficient of Variation, Poincaré SD2, and Shannon Entropy were decreased during the CON compared with the WR3:1 when core temperature exceeded 38°C and after 1 hour of continuous work (P < .05). Also, 4 of the 12 HRV indices studied were reduced at CON compared with WR1:1 after 2 hours of accumulated work time (P < .05). Participants worked longer before core temperature reached 38°C during the WR1:1 and the WR3:1, compared with CON (P < .05).

CONCLUSIONS

Incorporating breaks during moderate-to-heavy work in the heat for older adults can reduce autonomic stress and prolong the work performed at safe core temperature levels. The TLV WR1:1 provides increased cardiac protection for older workers, as compared with the CON and the WR3:1.

Heart rate variability in older men on the day following prolonged work in the heat

Susceptibility to heat illness during physically demanding work in hot environments is greater on the second of two consecutive workdays. While it has been demonstrated that heat storage is exacerbated on the second compared to first workday in older workers (50-65 yr), the effects on heart rate variability (HRV), an established surrogate of cardiac autonomic modulation, remain unclear. This study evaluated HRV in older workers on the day following prolonged work in the heat. Electrocardiogram was recorded in nine older (53-64 yr) males at rest, during three 30-min bouts of semi-recumbent cycling at fixed rates of metabolic heat production (150, 200, 250 W/m²), each separated by 15-min recovery. Experiments were conducted in hot-dry conditions (40 °C, 20% relative humidity), immediately prior to (Day 1), and on the day following (Day 2), a prolonged work simulation (∼7.5 hr) involving moderate intensity intermittent exercise in hot-dry conditions (38 °C, 34% relative humidity). Core temperature, as well as time, frequency, and nonlinear HRV indices were derived for analysis during rest, the final 5-min of exercise at the highest heat production and recovery. The change in core temperature at the end of work (mean ±SD) was significantly greater on Day 2 (1.0 °C ±0.3) relative to Day 1 (0.8 °C ±0.2; p < 0.01). Heart rate, however, did not significantly differ between days 1 and 2 at rest (Day 1, 59 ±11 bpm; Day 2, 62 ±13 bpm), during exercise (Day 1, 113 ±21 bpm; Day 2, 114 ±18 bpm ) and at the end of recovery (Day 1, 75 ±16 bpm; Day 2, 76 ±12 bpm). Likewise, there were no significant differences in any HRV indices derived from time, frequency, and nonlinear domains (all p > 0.05). Prolonged work in the heat did not modulate next-day heart rhythms, as reflected by HRV, despite augmented core temperature. While HRV can reflect physiological aspects of cardiac autonomic stressors, these findings indicate it does not provide a means to identify exacerbated heat strain in older workers over consecutive work shifts in the heat.

Sympathetic nervous system activation and heart failure: Current state of evidence and the pathophysiology in the light of novel biomarkers

Heart failure (HF) is a complex clinical syndrome characterized by the activation of at least several neurohumoral pathways that have a common role in maintaining cardiac output and adequate perfusion pressure of target organs and tissues. The sympathetic nervous system (SNS) is upregulated in HF as evident in dysfunctional baroreceptor and chemoreceptor reflexes, circulating and neuronal catecholamine spillover, attenuated parasympathetic response, and augmented sympathetic outflow to the heart, kidneys and skeletal muscles. When these sympathoexcitatory effects on the cardiovascular system are sustained chronically they initiate the vicious circle of HF progression and become associated with cardiomyocyte apoptosis, maladaptive ventricular and vascular remodeling, arrhythmogenesis, and poor prognosis in patients with HF. These detrimental effects of SNS activity on outcomes in HF warrant adequate diagnostic and treatment modalities. Therefore, this review summarizes basic physiological concepts about the interaction of SNS with the cardiovascular system and highlights key pathophysiological mechanisms of SNS derangement in HF. Finally, special emphasis in this review is placed on the integrative and up-to-date overview of diagnostic modalities such as SNS imaging methods and novel laboratory biomarkers that could aid in the assessment of the degree of SNS activation and provide reliable prognostic information among patients with HF.

Anabolic-androgenic steroids and brain injury: miRNA evaluation in users compared to cocaine abusers and elderly people

Anabolic-androgenic steroids (AASs) can be used to treat both hormonal diseases and other pathologies characterized by muscle loss (aging, cancer, and AIDS). Even if the adverse effects related to the misuse of AASs have been well studied in different systems and apparatuses, knowledge about brain damage is poor.In this scenario, this experimental study aimed to analyze the role of several microRNAs (miRNAs) in brain damage after AAS misuse, to better comprehend the underlying mechanisms. The research hypothesis at the base of this experimental study is that the chronic use of AASs may be associated to brain damage with a dysregulation of these miRNAs. Moreover, miRNA expression values were compared among three different groups, "AAS" group, "Cocaine" group and "Aging" group, in order to define if AAS brain damage can be compared with the brain impairment linked to aging and/or cocaine assumption.This experimental study revealed that the tested miRNAs (hsa-miR-21-5p, hsa-miR-34a-5p, hsa-miR-124-5p, hsa-miR-132-3p, and hsa-miR-144-3p) were overexpressed in all enrolled groups. In the light of the presented results, the identification of specific circulating and/or tissue biomarkers is challenging for the scientific community. Further studies with larger samples are needed to confirm these interesting findings.

Cardiac autonomic modulation in type 1 diabetes during exercise-heat stress

AIMS

Cardiac autonomic modulation, as assessed by heart rate variability (HRV), is independently attenuated by both type 1 diabetes (T1D) and exercise-heat stress, although their combined effects remain unclear. We therefore assessed HRV during exercise-heat stress in young individuals (18-37 years) with (n = 14) and without type 1 diabetes (n = 14).

METHODS

Participants completed 30-min seated rest and three, 30-min bouts of semi-recumbent cycling at light, moderate, and vigorous metabolic heat productions (200, 250, 300 W/m², respectively), each followed by 30-min recovery. Body core temperature (T_core) and electrocardiogram were recorded throughout and analyzed during the final 5-min of rest and each exercise period.

RESULTS

Relative to baseline, T_core was increased in both groups, albeit to a greater extent in type 1 diabetes during vigorous exercise (T1D, 1.1 ± 0.3 °C; control, 0.8 ± 0.3 °C; P < 0.05). Overall HRV (as reflected by entropy) was attenuated throughout exercise relative to baseline in both groups, with the magnitude of the reduction greater in type 1 diabetes during vigorous exercise (T1D, - 108%; control, - 70%; P < 0.05).

CONCLUSIONS

Given the negative correlations between decreased HRV and cardiac risk, our novel observations indicate that vigorous exercise in hot environments may pose a health concern for individuals with type 1 diabetes.

Systolic and diastolic function in chronic spinal cord injury

Individuals with spinal cord injury develop cardiovascular disease more than age-matched, non-injured cohorts. However, progression of systolic and diastolic dysfunction into cardiovascular disease after spinal cord injury is not well described. We sought to investigate the relationship between systolic and diastolic function in chronic spinal cord injury to describe how biological sex, level, severity, and duration of injury correlate with structural changes in the left ventricle. Individuals with chronic spinal cord injury participated in this study (n = 70). Registered diagnostic cardiac sonographers used cardiac ultrasound to measure dimensions, mass, and systolic and diastolic function of the left ventricle. We found no significant relationship to severity or duration of injury with left ventricle measurements, systolic function outcome, or diastolic function outcome. Moreover, nearly all outcomes measured were within the American Society of Echocardiography-defined healthy range. Similar to non-injured individuals, when indexed by body surface area (BSA) left ventricle mass [-14 (5) g/m2, p < .01], end diastolic volume [-6 (3) mL/m², p < .05], and end systolic volume [-4 (1) mL/m², p < .01] were significantly decreased in women compared with men. Likewise, diastolic function outcomes significantly worsened with age: E-wave velocity [-5 (2), p < .01], E/A ratio [-0.23 (0.08), p < .01], and e’ velocity [lateral: -1.5 (0.3) cm/s, p < .001; septal: -0.9 (0.2), p < .001] decreased with age while A-wave velocity [5 (1) cm/s, p < .001] and isovolumic relaxation time [6 (3) ms, p < .05] increased with age. Women demonstrated significantly decreased cardiac size and volumes compared with men, but there was no biological relationship to dysfunction. Moreover, individuals were within the range of ASE-defined healthy values with no evidence of systolic or diastolic function and no meaningful relationship to level, severity, or duration of injury. Decreases to left ventricular dimensions and mass seen in spinal cord injury may result from adaptation rather than maladaptive myocardial remodeling, and increased incidence of cardiovascular disease may be related to modifiable risk factors.

Inverse associations between parasympathetic activity and cognitive flexibility in African Americans: Preliminary findings

Previous research suggests that vagal activity and executive function (EF) are positively associated. However, existing data exploring the relationship between HRV and EF remains limited. Though Blacks may have higher HRV, they remain underrepresented in previous research examining HRV and EF. The current study aimed to determine the relationship between EF and HRV in a sample of 92 Black undergraduates (Mean age = 20.32, SD = 2.28). Participants wore an 6‑lead ambulatory electrocardiographic impedance monitoring system to obtain the root mean square of interbeat interval differences (rMSSD) and Cardiac Sympathetic Index. After baseline autonomic activity assessment, participants completed the Berg Card Sorting Test. Utilizing hierarchical regression analyses, HRV was negatively associated with correct responses (Beta = -0.40, SE = 0.04, p=0.01) and categories experienced (Beta = -0.37, SE = 0.01, p=0.01), and positively associated with total errors (Beta = 0.39, SE =0.04, p=0.01). To further elucidate these findings, participants were assigned to coinhibition (n = 12), parasympathetically dominant (n = 34), sympathetically dominant (n = 35), or coactivation (n = 11) autonomic space subgroups. Participants in the sympathetically dominant subgroup completed more categories (M = 6.86, SD = 2.13) and committed fewer errors (M = 30.63, SD = 11.53) than their parasympathetic counterparts (M = 5.74, SD = 2.44; M = 43.29, SD = 18.83, respectively). This study suggests that a state of sympathetic arousal immediately prior to the administration of an EF task, may aid in better task performance.

Can lavender oil inhalation help to overcome dental anxiety and pain in children? A randomized clinical trial

Aromatherapy with essential oils can be used to relieve children. The aim of this study was to evaluate the correlations between psychological and physiologic findings after lavender oil inhalation among children assigned to undergo tooth extraction. A total of 126 children aged between 6 and 12 years were enrolled in the study. The groups were randomly divided into control and lavender groups. The lavender group inhaled 100% lavender oil for 3 min before the interventions, the control group received no prior application. Psychological assessments were made using face image scale (FIS), Face, Legs, Activity, Cry, Consolability (FLACC) and Wong-Baker pain rating scale (WBS). Physiologic changes were assessed using vital signs evaluations. All parameters were noted prior to applications, after inhalation, anesthesia injection, and tooth extraction. The lavender group showed significant lower anxiety and pain scores after tooth extraction (p < 0.05). Significantly lower levels of blood pressures and a significant pulse rate drop were found after inhalation in the lavender group. A statistically significant increase in heart rate was observed after anesthesia injection and tooth extraction in the control group (p < 0.05).Conclusion: Lavender oil can be preferred as a treatment of choice in routine pediatric dentistry.Trial registration number: NCT04115891 (Lavender Oil Inhalation Help to Overcome Dental Anxiety Among Children)What is Known:• Dental anxiety is the most common factor that causes children to have difficulty with the dentist and their parents during treatment.• Aromatherapy with essential oils can be used to relieve children.What is New:• Aromatherapy with lavender oil relieves the child by reducing the level of anxiety and facilitates dental treatment.• During surgical procedures such as local anesthesia and tooth extraction, lavender oil inhalation decreases pain levels of children.

Association between Micronutrients and Heart Rate Variability: A Review of Human Studies

Heart rate variability (HRV) is a measure of the variation between consecutive heartbeats. It provides a marker of the interplay between the parasympathetic and sympathetic nervous systems, and there is an increasing body of evidence confirming an increased HRV is associated with better mental and physical health. HRV may be a useful marker of stress as it represents the ability of the heart to respond to a variety of physiological and environmental stimuli. HRV tends to decrease as we age and is positively associated with physical activity, fitness, and healthier lifestyles. The relation between HRV and micronutrients (vitamins and minerals) has also received some attention in the research literature. In this review, cross-sectional and interventional studies on human populations examining the relation between HRV and micronutrients are appraised. Micronutrients identified and examined in this review include vitamins D, B-12, C, and E; the minerals magnesium, iron, zinc, and coenzyme Q10; and a multivitamin-mineral formula. Due to the paucity of research and significant heterogeneity in studies, definitive conclusions about the effects of these micronutrients on HRV cannot be made at this time. However, there is accumulating evidence suggesting deficiencies in vitamins D and B-12 are associated with reduced HRV, and zinc supplementation during pregnancy can have positive effects on HRV in offspring up until the age of 5 y. To further elucidate the relation between micronutrients and HRV, additional robustly designed and adequately powered studies are required.

Severe Cardiac Dysautonomia and Sudden Death in a Patient Presenting with Anginal Symptoms in Absence of Cardiovascular and Other Diseases: A Case Report

Angina is a type of chest pain, experienced by patients with ischemic heart diseases. Cardiac autonomic modulation as assessed by heart rate variability and baroreflex sensitivity is found reduced in ischemic heart disease patients. Marked reduction in heart rate variability and baroreflex sensitivity in ischemic heart disease patients is found associated with sudden cardiac death. We report a case of a 35-year-old man who presented with angina for the last few months. Thorough investigations showed no evidence of any cardiac or other systemic diseases. However, his cardiovascular autonomic modulation (as assessed by heart rate variability) and spontaneous baroreflex sensitivity were markedly reduced. The patient had sudden death within 6 months of follow-up. Reportedly, no other specific abnormalities were found before death. This case report suggests that patients presenting with typical chest pain as angina may have severe dysautonomia and risk of sudden death even in the absence of cardiovascular or any other known end-organ diseases.

Autonomic Nervous System and Cognitive Impairment in Older Patients: Evidence From Long-Term Heart Rate Variability in Real-Life Setting

Background: In geriatric age, cognitive impairment and cardiovascular disorders are frequent comorbidities. Age-related anatomical and functional cardiac changes, including the autonomic system, could interfere with the control of different cognitive domains. Therefore, we assess the relationship between long-term heart rate variability (HRV), as a measure of autonomic nervous system (ANS) functioning, and cognitive performance in elderly patients representative of outpatients in a real-life setting.

Methods: Of 155 elderly outpatients (aged >65 years) screened, 117 enrolled patients underwent anthropometric evaluation, cardiac assessment by 12-lead electrocardiogram, 24-h ECG recording, and blood pressure (BP) measurement, as well as global cognitive evaluation by a standardized multidimensional assessment, including the Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment test (MoCA). HRV analysis was performed on 24-h ECG recordings focusing on time-domain indices [Standard deviation of the NN intervals (SDNN), standard deviations of 5-min mean values of the NN intervals for each 5-min interval (SDANN), and root mean squares of successive differences of the NN intervals (RMSSD)] and on frequency-domain measurements [heart rate (HR), low frequency (LF), high frequency (HF), and LF/HF]. Multivariate linear analysis was used to explore the influence of the HRV significant variables on MMSE and MoCA test values.

Results: The MMSE and MoCA scores were both significantly and positively correlated with the sympathetic system parameters (SDNN, SDANN, LF, and LF/HF ratio), but not with the parasympathetic system parameters (RMSSD and HF). Multivariate analysis confirms this relationship.

Conclusions: Our results show that, in a representative real-life community elderly population, an increased sympathetic activity, but not decreased vagal activity, is associated with better cognitive performances. These results support the sympathetic autonomic function, in that the relationship between better cognitive performances and a moderate prevalence of autonomic function appears dependent on long-term changes in heart rate, mediated by sympathetic activation.

Early Detection of Sudden Cardiac Death by Using Ensemble Empirical Mode Decomposition-Based Entropy and Classical Linear Features From Heart Rate Variability Signals

Sudden cardiac death (SCD), which can deprive a person of life within minutes, is a destructive heart abnormality. Thus, providing early warning information for patients at risk of SCD, especially those outside hospitals, is essential. In this study, we investigated the performances of ensemble empirical mode decomposition (EEMD)-based entropy features on SCD identification. EEMD-based entropy features were obtained by using the following technology: (1) EEMD was performed on HRV beats to decompose them into intrinsic mode functions (IMFs), (2) five entropy parameters, namely Rényi entropy (RenEn), fuzzy entropy (FuEn), dispersion Entropy (DisEn), improved multiscale permutation entropy (IMPE), and Renyi distribution entropy(RdisEn), were computed from the first four IMFs obtained, which were named EEMD-based entropy features. Additionally, an automated scheme combining EEMD-based entropy and classical linear (time and frequency domains) features was proposed with the intention of detecting SCD early by analyzing 14 min (at seven successive intervals of 2 min) heart rate variability (HRV) in signals from a normal population and subjects at risk of SCD. Firstly, EEMD-based entropy and classical linear measurements were extracted from HRV beats, and then the integrated measurements were ranked by various methodologies, i.e., t-test, entropy, receiver-operating characteristics (ROC), Wilcoxon, and Bhattacharyya. Finally, these ranked features were fed into a k-Nearest Neighbor algorithm for classification. Compared with several state-of-the-art methods, the proposed scheme firstly predicted subjects at risk of SCD up to 14 min earlier with an accuracy of 96.1%, a sensitivity of 97.5%, and a specificity of 94.4% 14 min before SCD onset. The simulation results exhibited that EEMD-based entropy estimators showed significant difference between SCD patients and normal individuals and outperformed the classical linear estimators in SCD detection, the EEMD-based FuEn and IMPE indexes were particularly useful assessments for identification of patients at risk of SCD and can be used as novel indices to reveal the disorders of rhythm variations of the autonomic nervous system when affected by SCD.

Physical Activity as a New Tool to Evaluate the Response to Omalizumab and Mepolizumab in Severe Asthmatic Patients: A Pilot Study

Asthma is a chronic inflammatory airway disease, representing one of the most severe pathologies in developed countries. Based on a report of the World Health Organization (WHO), it affects about 300 million people worldwide. Few studies have analyzed the effects of daily life physical activity (PA) levels in patients with asthma: moreover, little research has been carried out on PA levels in patients suffering from severe asthma (SA). This study aimed to investigate the PA levels in two groups of patients suffering from SA; in particular, this study analyzed the changes that occur in patients treated with biologic therapy (BT group) and patients who underwent traditional treatment (TT group) over 6 months. Moreover, this study represents a pilot study because, to the best of our knowledge, it is the first investigation that analyzed if the kind of biologic drug (omalizumab or mepolizumab) can produce differences in the PA levels of SA patients. Fifty SA patients were enrolled and PA parameters were monitored for 6 months. Subjects were divided into two treatment groups: TT (20 patients) and BT (30 patients), the BT group was further subdivided according to the drugs used (15, omalizumab; 15, mepolizumab). During drug treatment, all subjects improved their PA levels: indeed, considering the intragroup variation, the PA levels were significantly higher comparing the T6 levels to baseline (T0, p < 0.01). Considering the intragroup variation, it is very interesting to note that biologic therapy improved PA levels compared to the effects of traditional therapy; while at T0 there were no significant differences in the steps per day (SPD) values between the two groups (T0, p = 0.85), the differences become statistically significant at T1, T3, and T6 (T1, p = 0.019; T3, p = 3.48x10⁻⁶; T6, p = 4.78x10⁻¹⁰). As expected, the same differences were reported analyzing the energy expenditure data. In conclusion, this pilot study reports a positive relationship between biologic drug therapy and PA patterns, even if further studies are needed.

Aerobic Exercise and Metabolic Syndrome: The Role of Sympathetic Activity and the Redox System

BACKGROUND

Aerobic exercise can greatly assist in reducing collateral effects of metabolic syndrome (MetS). Moreover, aerobic exercise is associated with sympathetic activation and adaptive responses to sustain muscle engagement, changes in the release of Orexin A, a pleiotropic neuropeptide.

AIM

The aim of this study was to analyze the beneficial effects of aerobic exercise without dietary changes, in a cohort of MetS subjects, focusing on the role of sympathetic and orexinergic activity. Several blood parameters linked to MetS ROS production, heart rate, galvanic skin response, d-ROM test, and Orexin A serum levels were evaluated in ten males with MetS (BMI 30-34.9) before and after a period of 6 months of aerobic exercise compared to ten healthy subjects.

METHODS

Ten male subjects (aged 54 ± 4.16) with MetS (MetS group) and ten healthy males (aged 49.7 ± 2.79, Healthy group) were told about the study protocol and possible risks, signed the informed consent, and voluntarily participated in the study. Several blood parameters were evaluated in the two tested groups and were re-evaluated in the MetS group after 6 months of training (MetS6M group). The training protocol consisted of more than 30 min/day of walking (average speed of 4.5 km/h) and 3 days/week of aerobic activities (jogging under heart rate control - 120-140 bpm for 45 min).

RESULTS

The results showed that exercise induced a significant increase in GSR and plasma Orexin A but no significant increase in d-ROM values. Significant decreases in the serum ALT enzyme, triglycerides, and total cholesterol were found, while the HDL levels were significantly higher. Finally, a significant reduction of BMI and resting HR were reported.

CONCLUSION

The results of this study confirm that physical activity is associated with sympathetic activation, having a pivotal role against adverse effects linked to MetS. Moreover, this study demonstrates that, in patients with MetS, Orexin A is involved in hormonal adaptations to exercise.

Non-contact and real-time measurement of heart rate and heart rate variability using microwave reflectometry

In this paper, we present noncontact and noninvasive vital signal detection using a microwave reflectometer. Elimination of noise components due to random movement of human subjects has been the biggest issue for microwave measurement. Appropriate filtering, amplitude control of the reflectometer signal, and cross correlation among multiple reflectometers together with new algorithms have enabled motion artifact elimination, signal peak detection, and data processing for various parameters related to heart rate (HR) and heart rate variability (HRV). We focus here on the real time measurements of instantaneous HR and HRV for practical use. The evaluation by microwave reflectometry is completely noninvasive and feasible even through clothing, which is extremely effective for health maintenance in daily life as well as for preventing sudden death related to, for example, coronary heart disease and ventricular arrhythmia.

Relationship between heart rate variability and carotid intima-media thickness in the Brazilian Longitudinal Study of Adult Health - ELSA-Brasil

BACKGROUND

Both increased carotid intima-media thickness (cIMT) and low heart rate variability (HRV) have been associated with cardiovascular mortality and morbidity. Thus, the aim of this study was to investigate whether cardio autonomic alterations are accompanied or not by subclinical atherosclerosis in participants of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil).

METHODS

cIMT measures and 5-min HRV analyses were performed in apparently healthy adults. Heart rate variability was evaluated by linear time and frequency domain analyses. cIMT was defined as the average between the mean left and mean right cIMT values and was analysed as continuous and categorized variables (P≥75 or P<75). Multiple linear models using continuous variables and multivariate logistic regression with categorized cIMT and HRV quartiles were performed.

RESULTS

Out of 7256 participants eligible for analyses, 23·4% presented cIMT ≥ 75th percentile. Heart rate variability variables were reduced in cIMT ≥ P75 in comparison with cIMT < P75: SDNN 33·0 versus 37·0 ms, P<0·001; RMSSD 22·0 versus 26·0 ms, P<0·001; LF 191·0 versus 260·0 ms² , P<0·001; HF 164·0 versus 238·5 ms² , P<0·001. In crude analysis, an increased odds ratio for cIMT ≥ P75 was verified within the lowest two quartiles of LF and HF, but significances did not remain after adjustments for anthropometric and clinical variables.

CONCLUSIONS

Considering the entire sample, subjects with cIMT ≥ P75 presented lower HRV values, but no independent relationships were detected between cIMT and HRV after multivariate adjustment.

Mechanisms supporting potential use of bone marrow-derived mesenchymal stem cells in psychocardiology

Despite great efforts made in recent years, globally cardiovascular disease (CVD) remains the most common and devastating disease. Pharmacological, interventional and surgical treatments have proved to be only partly satisfactory for the majority of patients. A major underlying cause of poor prognosis is a high comorbidity rate between CVD and mental illness, which calls for the approaches of psychocardiology. As psychiatric disorders and CVD can influence each other bidirectionally, it is necessary to develop novel therapies targeting both systems simultaneously. Therefore, innovative stem cell (SC) therapy has become the most promising treatment strategy in psychocardiology. Bone marrow-derived mesenchymal stem/stromal cells (BM-MSCs), among all different types of SCs, have drawn the most attention due to unique advantages in terms of ethical considerations, low immunogenicity and simplicity of preparation. In this review, we survey recent publications and clinical trials to summarize the knowledge and progress gained so far. Moreover, we discuss the feasibility of the clinical application of BM-MSCs in the area of psychocardiology.

Anti-neuroinflammation ameliorates systemic inflammation-induced mitochondrial DNA impairment in the nucleus of the solitary tract and cardiovascular reflex dysfunction

BACKGROUND

Decreased heart rate variability (HRV) leads to cardiovascular diseases and increased mortality in clinical studies. However, the underlying mechanisms are still inconclusive. Systemic inflammation-induced neuroinflammation is known to impair the autonomic center of cardiovascular regulation. The dynamic stability of blood pressure and heart rate (HR) is regulated by modulation of the reciprocal responses of sympathetic and parasympathetic tone by the baroreflex, which is controlled by the nucleus of the solitary tract (NTS).

METHODS

Systemic inflammation was induced by E. coli lipopolysaccharide (LPS, 1.2 mg/kg/day, 7 days) peritoneal infusion via an osmotic minipump in normotensive Sprague-Dawley rats. Systolic blood pressure (SBP) and HR were measured by femoral artery cannulation and recorded on a polygraph under anesthesia. The low-frequency (LF; 0.25-0.8 Hz) and high-frequency (HF; 0.8-2.4 Hz) components of SBP were adopted as the indices for sympathetic vasomotor tone and parasympathetic vasomotor tone, while the baroreflex effectiveness index (BEI) was adopted from the analysis of SBP and pulse interval (PI). The plasma levels of proinflammatory cytokines and mitochondrial DNA (mtDNA) oxidative damage were analyzed by ELISA. Protein expression was evaluated by Western blot. The distribution of oxidative mtDNA was probed by immunofluorescence. Pharmacological agents were delivered via infusion into the cisterna magna with an osmotic minipump.

RESULTS

The suppression of baroreflex sensitivity was concurrent with increased SBP and decreased HR. Neuroinflammatory factors, including TNF-α, CD11b, and Iba-1, were detected in the NTS of the LPS group. Moreover, indices of mtDNA damage, including 8-OHdG and γ-H2AX, were significantly increased in neuronal mitochondria. Pentoxifylline or minocycline intracisternal (IC) infusion effectively prevented mtDNA damage, suggesting that cytokine and microglial activation contributed to mtDNA damage. Synchronically, baroreflex sensitivity was effectively protected, and the elevated blood pressure was significantly relieved. In addition, the mtDNA repair mechanism was significantly enhanced by pentoxifylline or minocycline.

CONCLUSION

These results suggest that neuronal mtDNA damage in the NTS induced by neuroinflammation could be the core factor in deteriorating baroreflex desensitization and subsequent cardiovascular dysfunction. Therefore, the enhancement of base excision repair (BER) signaling in mitochondria could be a potential therapeutic strategy for cardiovascular reflex dysregulation.

Normalization of heart rate variability with taurine and meldonium complex in post-infarction patients with type 2 diabetes mellitus

The purpose of this study is to scrutiny the Dynamics of heart rate variability (HRV) in patients with PICS with 2nd type DM against the background of Taurine (TN) and meldonium (ME). The results of the investigations prove the decrease of the oxidative stress, which is basis of DACN, under the influence of sulfur-containing amino acid taurine (TN), and meldonium (ME) — a competitive inhibitor of gamma-butyrobetaine hydroxylase. Biochemical mechanisms of synergistic action of ME and TN are also described. The results of the studies of 98 patients with PICS and concomitant 2nd type diabetes mellitus were analyzed. They were distributed by simple randomization method into two groups, comparable according to age and sex: the main group (MG) (n = 68): and group of comparison (GoC) (n = 30). HRV was evaluated twice daily at the Cardiosense HMEGG system: at baseline and after 12 weeks of treatment. For the assessment of HRV the frequency and spectral parameters were used. While evaluating the different methods of treatment, their influence on the range of spectral and time indices of HRV was determined (p = 0.001 by the criterion of Kruskall-Wallis). It was learned that the combined application of ME and TN gives a statistically significant (p <0.01) increase of SDNN, HF at night, pNN — on 50% by day (p <0.01, p <0.001 and p <0.01 respectively), and statistically significant decrease in LF at night, compared to GHG.

Daily Heart Rate Variability Indices in Subjects with and Without Metabolic Syndrome Before and After the Elimination of the Influence of Day-Time Physical Activity

Background and Objectives: The available research shows conflicting data on the heart rate variability (HRV) in metabolic syndrome (MetS) subjects. The discrepancy suggests a methodical shortcoming: due to the influence of physical activity, the standard measuring of HRV at rest is not comparable with HRV assessment based on 24 h Holter monitoring, which is preferred because of its comprehensiveness. To obtain a more reliable measure and to clarify to what extent HRV is altered in MetS, we assessed a 24 h HRV before and after the elimination of the influence of physical activity. Materials and Methods: We investigated 69 metabolic syndrome (MetS) and 37 control subjects, aged 50–55. In all subjects, 24 h monitoring of electrocardiogram, blood pressure, and actigraphy profiles were conducted. To eliminate the influence of day-time physical activity on RR intervals (RRI), a linear polynomial autoregressive model with exogenous terms (ARX) was used. Standard spectral RRI analysis was performed. Results: Subjects with MetS had blunted HRV; the diurnal SDNN index was reliably lower in the MetS group than in control subjects. The elimination of the influence of physical activity did not reveal a significant HRV change in long-term indices (SDNN, SDANN, and SD2), whilst adjacent RRI values (RMSSD, pNN50, and SD1) and SDNN index significantly increased (p < 0.001). An increase in the latter indices highlighted the HRV difference between the MetS and control groups; a significant (p < 0.001) decrease of all short-term HRV variables was found in the MetS group (p < 0.01), and low-frequency spectral components were less pronounced in the MetS group. Conclusion: The application of a polynomial autoregressive model in 24 h HRV assessment allowed for the exclusion of the influence of physical activity and revealed that MetS is associated with blunted HRV, which reflects mitigated parasympathetic tone.

Geomagnetic disturbances driven by solar activity enhance total and cardiovascular mortality risk in 263 U.S. cities

BACKGROUND

Short-term geomagnetic disturbances (GMD) driven by the quasi-periodic 11-year cycle of solar activity have been linked to a broad range of adverse health effects, including cardiovascular diseases (CVD) and total deaths. We conducted a large epidemiological study in 263 U.S. cities to assess the effects of GMD on daily deaths of total, CVD, myocardial infarction (MI), and stroke.

METHODS

We employed a two-step meta-analysis approach, in which we estimated city-specific and season-stratified mortality risk associated with a GMD parameter (Kp index) in 263 U.S. cities. In addition, sensitivity analysis was performed to assess whether effect modification of particulate matter (PM2.5) in the prior day changed Kp index effects on daily deaths after adjusting for confounders.

RESULTS

We found significant association between daily GMD and total, CVD, and MI deaths. The effects were even stronger when we adjusted the models for 24-h PM2.5 for different seasons. For example, in the winter and fall one standard deviation of z-score Kp index increase was associated with a 0.13 and 0.31% increase in total deaths, respectively (Winter: p = 0.01, 95% CI: 0.02 to 0.24; Fall: p = 0.00001; 95% CI: 0.23 to 0.4), without adjusting for PM2.5. The effects of GMD on total deaths were also observed in spring and summer in the models without PM2.5 (p = 0.00001). When the models were adjusted for PM2.5 the total deaths increased 0.47% in winter (p = 0.00001, 95% CI: 0.3 to 0.65) and by 0.23% in fall (p = 0.001, 95% CI: 0.09 to 0.37). The effects of GMD were also significant associated with MI deaths and CVD. No positive significant association were found between Kp and stroke. The GMD effects on deaths were higher than for 24 h-PM2.5 alone, especially in spring and fall.

CONCLUSION

Our results suggest that GMD is associated with total, CVD and MI deaths in 263 U. S cities. Increased mortality in the general population during GMD should be further investigated to determine whether those human physiological dynamics driven by variations in solar activity can be related to daily clinical cardiovascular observations.

Exercise benefits in cardiovascular disease: beyond attenuation of traditional risk factors

Despite strong scientific evidence supporting the benefits of regular exercise for the prevention and management of cardiovascular disease (CVD), physical inactivity is highly prevalent worldwide. In addition to merely changing well-known risk factors for systemic CVD, regular exercise can also improve cardiovascular health through non-traditional mechanisms. Understanding the pathways through which exercise influences different physiological systems is important and might yield new therapeutic strategies to target pathophysiological mechanisms in CVD. This Review includes a critical discussion of how regular exercise can have antiatherogenic effects in the vasculature, improve autonomic balance (thereby reducing the risk of malignant arrhythmias), and induce cardioprotection against ischaemia-reperfusion injury, independent of effects on traditional CVD risk factors. This Review also describes how exercise promotes a healthy anti-inflammatory milieu (largely through the release of muscle-derived myokines), stimulates myocardial regeneration, and ameliorates age-related loss of muscle mass and strength, a frequently overlooked non-traditional CVD risk factor. Finally, we discuss how the benefits of exercise might also occur via promotion of a healthy gut microbiota. We argue, therefore, that a holistic view of all body systems is necessary and useful when analysing the role of exercise in cardiovascular health.

Effect of chronic intermittent hypobaric hypoxia on heart rate variability in conscious rats

To examine the effect of chronic intermittent hypobaric hypoxia (CIHH) on heart rate variability (HRV), male adult Sprague Dawley rats were exposed to hypoxia (oxygen 11.1%) in a hypobaric chamber for 42 days, 6 hours each day, simulating an altitude of 5000 m. The body weight and blood pressure of rats were recorded once a week, electrocardiograms were analyzed continuously using biotelemetry, before, during and after CIHH treatment each day, and HRV was evaluated using spectrum analysis. No significant difference of body weight and blood pressure was found between CIHH and control rats. After 4 weeks of CIHH treatment, total power (TP) and very low-frequency component (VLF) were lower in CIHH rats than in control rats under hypobaric hypoxia condition. During CIHH treatment, low frequency (LF) was higher in 1 week and lower in 5-6 weeks in CIHH rats than control rats under hypobaric hypoxia, but not normoxic conditions. The high-frequency component (HF) was not changed during CIHH treatment, so LF/HF increased initially, and then recovered under the hypobaric hypoxia condition following 3 weeks of CIHH treatment. In addition, the HR was increased in CIHH rats after 4 weeks of CIHH treatment compared with control rats. Furthermore, HRV was altered significantly in control rats, but not in CIHH rats exposed to acute normobaric hypoxia. These data suggest that CIHH treatment modulates cardiac autonomic activity adaptively and inhibits the acute normobaric hypoxia-induced changes in HRV.

Immunodeficiency as a side effect of anabolic androgenic steroid abuse: a case of necrotizing myofasciitis

Even if there are well-known consequences of anabolic androgenic steroid (AAS) abuse, their full pathway of action is still being investigated. In this context, the presented case report aims to discuss and provide evidence of unusual adverse effects linked to immunodeficiency in an AAS abuser. In fact, this kind of chronic complication, even if not usually considered, may lead sudden death. In this case a 31-year-old aesthetic weightlifter, who presented to the emergency department due to an accidental fall that resulted in left thigh trauma. This subsequently developed into left thigh necrotizing myofasciitis in the following few days. Although surgery and hyperbaric therapy were carried out, the man died. An autopsy with complete biological sampling for toxicological studies was performed. This case highlights the close relationship between AAS abuse and immunodeficiency and highlights it's importance for further studies. However, it should be considered that of all the dangerous effects produced by AAS use, necrotizing fasciitis is not such an unusual consequence.

Effects of lunar dust simulant on cardiac function and fibrosis in rats

The objective of this study was to investigate the effects of lunar dust simulant (LDS) on cardiac function and fibrosis. In an in vivo experiment, after 3 weeks of exposure, electrocardiography (ECG) and histopathological and immunohistochemical analyses of the cardiac tissue were performed. Systemic inflammatory markers and genes and proteins associated with cardiac tissue fibrosis were examined. In an in vitro experiment, fibrosis-related factors were detected in H9c2 cells by western blot and the mechanism of myocardial fibrosis by LDS exposure was explored. LDS exposure significantly altered heart rate indicators, implying altered cardiac and autonomic system functions. LDS dose-dependently increased the type and number of ECG abnormalities, and increased serum inflammatory factors. In addition, pathological changes in the myocardial tissue were observed through hematoxylin and eosin, Masson, and immunohistochemical staining; the expression of genes and proteins related to fibrosis in the myocardial tissue was also altered. These findings indicate that LDS exposure causes systemic inflammatory lesions that affect autonomic function, leading to inflammatory myocardial fibrosis. And its mechanisms involve the mediation of the nuclear factor-E2-related factor (Nrf2)/nicotinamide adenine dinucleotide phosphate oxidase 4 (NOX4) redox balance.

Socio-economic differences in incidence, bystander cardiopulmonary resuscitation and survival from out-of-hospital cardiac arrest: A systematic review

BACKGROUND

Individuals with a low socioeconomic status (SES) may have a greater mortality rate from out of hospital cardiac arrest (OHCA) than those with a high SES. We explored whether SES disparities in OHCA mortality manifest in the incidence of OHCA, the chance of receiving bystander cardiopulmonary resuscitation (CPR) or in the chance of surviving an OHCA. We also studied whether sex and age differences exist in such SES disparities.

METHODS

The Medline, Embase and Scopus databases were searched from 01-01-1993 until 31-01-2019. Studies utilising any study design or population were included. Studies were included if the exposure was SES of the OHCA victim or the OHCA location and the outcome was either OHCA incidence, CPR provision and/or survival rate after OHCA. Study selection and quality assessment were conducted by two reviewers independently. Descriptive data and measures of association were extracted, both in the total study population and in subgroups stratified by age and/or sex. This review was carried out following the PRISMA guidelines.

RESULTS

Overall 32 studies were included. Twelve studies reported on OHCA incidence, thirteen on bystander CPR provision and fourteen on survival. Some evidence for SES differences was found in each identified stage. In all the studies on incidence, SES was measured over the area of the OHCA victims' residence and was consistently associated with OHCA. In studies on bystander CPR, SES of the area in which the OHCA occurred was associated with bystander CPR, while evidence on individual SES was lacking. In studies on OHCA survival, SES of the victim measured at the individual level and SES of the area in which the OHCA occurred were associated, while SES of the victim, measured at the area of residence was not. Studies reporting age and sex differences in the SES trends were scarce.

CONCLUSION

SES disparities in OHCA mortality likely manifest in OHCA incidence, bystander CPR provision and survival rate after OHCA. However, there is a distinct lack of data on SES measured at the individual level and on differences within subgroups, e.g. by sex and age.

Neural correlates of anticipatory cardiac deceleration and its association with the speed of perceptual decision-making, in young and older adults

Warning stimuli in sensorimotor tasks induce a state of preparedness characterized by increased alertness, focused attention and immobility. This state of attentive anticipation is associated with heart rate deceleration. Ageing affects the amplitude of the anticipatory cardiac deceleration responses; yet, the impact of this physiological change on cognitive performance is still to be elucidated. In fact, how cardiac deceleration relates to brain function and cognitive performance in the context of perceptual decision-making and different levels of decision complexity remains unknown. Here, we aimed to investigate the relationship between cardiac deceleration, brain function, and performance in perceptual decision tasks and how these associate with age-related changes. We measured simultaneously the electrocardiogram, the pupilogram, and the electroencephalogram in 36 young and 39 older adults, while they were engaged in two auditory cued reaction time tasks: a detection task and a go/no-go task requiring inhibitory control. We observed robust cardiac deceleration responses that increased with increasing task complexity. Notably, stronger modulation of the cardiac response across tasks was associated with the ability to maintain response speed as decision complexity increased suggesting a link between cardiac deceleration and facilitation of perceptual decisions. Additionally, cardiac deceleration appears to have a cortical origin as it correlated with frontocentral event-related potentials. In contrast, beta oscillations at baseline and task-related beta suppression were not predictive of cardiac deceleration suggesting a dissociation between sensorimotor oscillatory activity and this cardiac response. Importantly, we found age-related changes in anticipatory cardiac deceleration associated with deficits in perceptual decision-making.

Human Brain Injury and miRNAs: An Experimental Study

Brain damage is a complex dysfunction that involves a variety of conditions whose pathogenesis involves a number of mediators that lead to clinical sequelae. For this reason, the identification of specific circulating and/or tissue biomarkers which could indicate brain injury is challenging. This experimental study focused on microRNAs (miRNAs), a well-known diagnostic tool both in the clinical setting and in medico-legal investigation. Previous studies demonstrated that specific miRNAs (miR-21, miR-34, miR-124, miR-132, and miR-200b) control important target genes involved in neuronal apoptosis and neuronal stress-induced adaptation. Thus, in this experimental setting, their expression was evaluated in three selected groups of cadavers: drug abusers (cocaine), ischemic-stroke-related deaths, and aging damage in elder people who died from other neurological causes. The results demonstrated that the drug abuser group showed a higher expression of miR-132 and miR-34, suggesting a specific pathway in consumption-induced neurodegeneration. Instead, miR-200b and miR-21 dysregulation was linked to age-related cognitive impairment, and finally, stroke events and consequences were associated with an alteration in miR-200b, miR-21, and miR-124; significantly higher levels of this last expression are strongly sensitive for ischemic damage. Moreover, these results suggest that these expression patterns could be studied in other biological samples (plasma, urine) in subjects with brain injury linked to aging, drug abuse, and stroke to identify reliable biomarkers that could be applied in clinical practice. Further studies with larger samples are needed to confirm these interesting findings.

Comparative effects of amiodarone and dronedarone treatments on cardiac function in a rabbit model

AIM

The objective of the study was to compare the effects of amiodarone (AM) and dronedarone (DR) on heart rate variability (HRV) and cardiac contractility in a rabbit model.

MATERIALS AND METHODS

A total of 16 male New Zealand white rabbits were divided into two groups, treated either with AM or DR at incremental dosages of 50 mg/kg/day (AM50 and DR50) and 100 mg/kg/day (AM100 and DR100), orally administrated for 7 days. At the end of each period, electrocardiograms were recorded during consciousness and analyzed using the short-term time and frequency domains of HRV. Standard echocardiography and speckle-tracking echocardiography were studied during immobilization with xylazine and ketamine.

RESULTS

The results showed that AM100 and DR100 significantly decreased heart rate, total power, low-frequency component, and low-to-high frequency ratio compared with baselines. Most echocardiogram parameters revealed no significant difference from baselines, except for the global circumferential plane strain rate and time to peak standard deviation of strain, which had statistical significances after treating with AM.

CONCLUSION

Both AM and DR possess negative chronotropy and reduce HRV, which may be explained by their sympathetic suppression and calcium channel blocking activities. Theoretically, both antiarrhythmic drugs may also possess negative inotropy, but only AM is shown to have a negative inotropic effect and reduces cardiac dyssynchrony in this model.

Dose-response relationship between very vigorous physical activity and cardiovascular health assessed by heart rate variability in adults: Cross-sectional results from the EPIMOV study

The minimum amount of physical activity needed to obtain health benefits has been widely determined. Unlikely, the impact of extreme amounts of very vigorous physical activity (VVPA, ≥ 8 metabolic equivalents) to the heart remains controversial. We aimed to evaluate the dose-response relationship between VVPA and heart rate variability (HRV) in adults. We selected 1040 asymptomatic individuals (60% women, 42 ± 15 years, 28 ± 6 kg/m2) from the Epidemiology and Human Movement Study (EPIMOV). Participants remained in the supine position for 10 min, and we selected an intermediate 5-min window for HRV analysis. The standard deviation of the RR intervals, root mean square of RR intervals, successive RR intervals that differ > 50 ms, powers of the low-and high-frequency bands and Poincaré plot standard deviations were quantified. Participants used a triaxial accelerometer (Actigraph GT3x+) above the dominant hip for 4-7 consecutive days for quantifying their physical activity. We also evaluated the maximum oxygen uptake ([Formula: see text]) during an exercise test. We stratified participants into five groups according to the VVPA in min/week (group 1, ≤ 1.50; 2, 1.51-3.16; 3, 3.17-3.54; 4, 3.55-20.75; and 5, > 20.75). The linear trends of the HRV through the quintiles of VVPA were investigated. We used logarithmic transformations to compare the five groups adjusted for age, sex, cardiovascular risk, and [Formula: see text]. We found a better HRV with increased VVPA for all HRV indices studied (p trend < 0.05). However, group 5 did not differ from group 4 (p > 0.05) for none of the indices. We conclude that there is an incremental benefit of VVPA on HRV of asymptomatic adults. Since we found neither additional benefits nor the harmful impact of amounts of VVPA as high as 22 min/week on HRV, our results should not discourage asymptomatic adults to perform VVPA.

Anabolic Androgenic Steroids: Searching New Molecular Biomarkers

Even if anabolic androgenic steroid (AAS) abuse is clearly associated with a wide spectrum of collateral effects, adolescents and athletes frequently use a large group of synthetic derivatives of testosterone, both for aesthetic uses and for improving performance. Over the last few years, the development of MicroRNA (miRNA) technologies has become an essential part of research projects and their role as potential molecular biomarkers is being investigated by the scientific community. The circulating miRNAs detection as a diagnostic or prognostic tool for the diagnosis and treatment of several diseases is very useful, because with a minimal quantity of sample (peripheral blood), miRNAs are very sensitive. Even more, miRNAs remain stable both at room temperature and during freeze-thaw cycles. These characteristics highlight the important role of miRNAs in the near future as new tools for anti-doping. The article provides a systematic review and meta-analysis on the role of miRNAs as new potential molecular biomarkers of AAS use/abuse. Particularly, this paper analyzed the “miRNA signature” use as biomarkers for health disorders, focusing on the organ damages which are related to ASS use/abuse. Moreover, this review aims to provide a future prospect for less invasive or non-invasive procedures for the detection of circulating miRNA biomarkers as doping assumption signaling.

Effects of Mind⁻Body Exercises (Tai Chi/Yoga) on Heart Rate Variability Parameters and Perceived Stress: A Systematic Review with Meta-Analysis of Randomized Controlled Trials

Background: Heart rate variability (HRV) as an accurate, noninvasive measure of the Autonomous Nervous System (ANS) can reflect mental health (e.g., stress, depression, or anxiety). Tai Chi and Yoga (Tai Chi/Yoga), as the most widely practiced mind–body exercises, have shown positive outcomes of mental health. To date, no systematic review regarding the long-lasting effects of Tai Chi/Yoga on HRV parameters and perceived stress has been conducted. Objective: To critically evaluate the existing literature on this topic. Methods: Five electronic databases (Web of Science, PubMed, Scopus, SportDiscus and Cochrane Library) were searched from the start of the research project to July 2018. Study selection, data extraction, and study quality assessment were independently carried out by two reviewers. The potentially identified randomized controlled trials (RCT) reported the useful quantitative data that were included only for meta-analysis. Results: meta-analysis of 17 medium-to-high quality RCTs showed significantly beneficial effects on HRV parameters (normalized low-frequency, Hedge’s g = −0.39, 95% CI −0.39 to −0.56, p < 0.001, I2 = 11.62%; normalized high-frequency, Hedge’s g = 0.37, 95% CI 0.22 to −0.52, p < 0.001, I2 = 0%; low-frequency to high-frequency ratio, Hedge’s g = −0.58, 95% CI −0.81 to −0.35, p < 0.001, I2 = 53.78%) and stress level (Hedge’s g = −0.80, 95% CI −1.17 to −0.44, p < 0.001, I2 = 68.54%). Conclusions: Stress reduction may be attributed to sympathetic-vagal balance modulated by mind–body exercises. Tai Chi/Yoga could be an alternative method for stress reduction for people who live under high stress or negative emotions.

Association between dysfunction of autonomic nervous system activity and mortality in schizophrenia

BACKGROUND

Patients with schizophrenia have a higher mortality risk than the general population. Additionally, the autonomic nervous system (ANS) activity of patients with schizophrenia is lower and more dysfunctional than that of the general population. Nonetheless, the association between ANS dysfunction and mortality in schizophrenia is unclear. The aim of this study was to investigate the association between ANS activity and mortality in schizophrenia and to evaluate the predictive values of heart rate variability for long-term survival.

METHODS

This study involves the 10-year follow-up of a sample population consisting of 59 Japanese inpatients with schizophrenia between 60 and 70 years of age from 2007 to 2016. The ANS activity of all patients was evaluated using heart rate variability in 2007.

RESULTS

Fifty-three participants could be followed up because they stayed in the hospital during the follow-up period. Of these patients, 11 died during follow-up. Their mean age at death was 70.55 ± 3.45 years. The parasympathetic activity of nonsurvivors was significantly lower than that of survivors, and multiple logistic regression analysis showed a significant association between death and parasympathetic activity.

CONCLUSION

We suggest that decreased parasympathetic activity could be associated with 10-year all-cause mortality in older schizophrenic patients.