Differential changes of autonomic nervous system function with age in man

Effect of lighting conditions on implantable collamer lens vault: Influence of anterior chamber and lens parameters

Purpose

To investigate the change in the vault of the implantable collamer lens (ICL) under dark-to-light conditions and its association with anterior chamber and lens parameters in patients undergoing ICL surgery.

Methods

In 76 eyes from 40 patients, preoperative anterior chamber volume (ACV), pupil diameter (PD), anterior chamber angle, central corneal thickness (CCT), white-to-white (WTW), lens thickness (LT), axial length (AL), spherical equivalent (SE) and patient's age were collected. Postoperative vault, PD and LT were measured under dark and light conditions using anterior segment optical coherence tomography (CASIA2; TOMEY, Japan), and changes and lens displacement under dark-to-light conditions were calculated. Mixed-effects models were used to analyze the correlation between the vault change and the anterior chamber and lens parameters of all subjects and the high-vault subgroup.

Results

The vault under light condition (648.36 ± 304.47 μm) was significantly smaller compared to the vault under dark condition (708.89 ± 316.15 μm). In all patients, vault change increased with the increase of age, lens displacement and PD change; and increased with the decrease of ACV, LT change and baseline vault (under dark condition). In the high-vault subgroup, vault change increased with the increase of CCT, lens displacement and PD change; and increased with the decrease of ACV.

Conclusions

ICL vault changes significantly from dark to light, influenced by age, ACV, PD change, LT change, lens displacement, and baseline vault. A higher baseline vault is correlated with a larger LT change, affecting the levels of accommodation under dark-to-light transition.

Calorie restriction anti-hypertrophic effects are associated with improved mitochondrial content, blockage of Ca2+-induced mitochondrial damage, and lower reverse electron transport-mediated oxidative stress

Calorie restriction is a nutritional intervention that reproducibly protects against the maladaptive consequences of cardiovascular diseases. Pathological cardiac hypertrophy leads to cellular growth, dysfunction (with mitochondrial dysregulation), and oxidative stress. The mechanisms behind the cardiovascular protective effects of calorie restriction are still under investigation. In this study, we show that this dietetic intervention prevents cardiac protein elevation, avoids fetal gene reprogramming (atrial natriuretic peptide), and blocks the increase in heart weight per tibia length index (HW/TL) seen in isoproterenol-induced cardiac hypertrophy. Our findings suggest that calorie restriction inhibits cardiac pathological growth while also lowering mitochondrial reverse electron transport-induced hydrogen peroxide formation and improving mitochondrial content. Calorie restriction also attenuated the opening of the Ca2+-induced mitochondrial permeability transition pore. We also found that calorie restriction blocked the negative correlation of antioxidant enzymes (superoxide dimutase and glutatione peroxidase activity) and HW/TL, leading to the maintenance of protein sulphydryls and glutathione levels. Given the nature of isoproterenol-induced cardiac hypertrophy, we investigated whether calorie restriction could alter cardiac beta-adrenergic sensitivity. Using isolated rat hearts in a Langendorff system, we found that calorie restricted hearts have preserved beta-adrenergic signaling. In contrast, hypertrophic hearts (treated for seven days with isoproterenol) were insensitive to beta-adrenergic activation using isoproterenol (50 nM). Despite protecting against cardiac hypertrophy, calorie restriction did not alter the lack of responsiveness to isoproterenol in isolated hearts harvested from isoproterenol-treated rats. These results suggest (through a series of mitochondrial, oxidative stress, and cardiac hemodynamic studies) that calorie restriction possesses beneficial effects against hypertrophic cardiomyopathy.

Assessing the effect of breed, age, and sex on muscarinic receptor distribution in atria and ventricles of turkeys

Atrial and ventricular myocardium from young (6-wk-old), young adult (3-6-mo-old), and aged (14-15-mo-old) meat-type (B.U.T. Big 6) and wild-type (Cröllwitzer) turkeys were used to study the influence of age and sex on cholinergic muscarinic receptors using [3H]-N-methyl-scopolamine (3H-NMS) binding studies. In both breeds, saturation experiments indicated the presence of regional-, sex-, and age-related differences in the density of cholinergic muscarinic receptors (Bmax), that is, a decrease or increase. Except for right atria, Bmax was decreased in both male and female B.U.T. Big 6 hearts with increasing age. Similarly, a negative correlation between Bmax and age could be seen in female and male atria of Cröllwitzer turkeys, while positive correlation could be seen in right and left ventricles of male, and only right ventricles of female Cröllwitzer turkeys. The affinity of the receptor (KD) was not affected by age, sex and breed. In all cardiac chamber tissues, the M2-subtype was shown to be predominant followed by the M3-subtype and to a lesser extent the M1-subtype. Aspects of this age-dependent remodeling of the heart differ between sexes, resulting in maladaptive changes in older turkeys with a high degree of frailty. These observations may help explain why males and females are susceptible to different cardiovascular diseases as they age and why frail older adults are most often affected by these diseases.

Variable cardiac responses in rhesus macaque monkeys after discrete mediodorsal thalamus manipulations

The control of some physiological parameters, such as the heart rate, is known to have a role in cognitive and emotional processes. Cardiac changes are also linked to mental health issues and neurodegeneration. Thus, it is not surprising that many of the brain structures typically associated with cognition and emotion also comprise a circuit-the central automatic network-responsible for the modulation of cardiovascular output. The mediodorsal thalamus (MD) is involved in higher cognitive processes and is also known to be connected to some of the key neural structures that regulate cardiovascular function. However, it is unclear whether the MD has any role in this circuitry. Here, we show that discrete manipulations (microstimulation during anaesthetized functional neuroimaging or localized cytotoxin infusions) to either the magnocellular or the parvocellular MD subdivisions led to observable and variable changes in the heart rate of female and male rhesus macaque monkeys. Considering the central positions that these two MD subdivisions have in frontal cortico-thalamocortical circuits, our findings suggest that MD contributions to autonomic regulation may interact with its identified role in higher cognitive processes, representing an important physiological link between cognition and emotion.

An Easy-to-Use Nomogram Based on SII and SIRI to Predict in-Hospital Mortality Risk in Elderly Patients with Acute Myocardial Infarction

Aim

Inflammatory response is closely associated with poor prognosis in elderly patients with acute myocardial infarction (AMI). The aim of this study was to develop an easy-to-use predictive model based on medical history data at admission, systemic immune inflammatory index (SII), and systemic inflammatory response index (SIRI) to predict the risk of in-hospital mortality in elderly patients with AMI.

Methods

We enrolled 1550 elderly AMI patients (aged ≥60 years) with complete medical history data and randomized them 5:5 to the training and validation cohorts. Univariate and multivariate logistic regression analyses were used to screen risk factors associated with outcome events (in-hospital death) and to establish a nomogram. The discrimination, calibration, and clinical application value of nomogram were evaluated based on receiver operating characteristic (ROC) curve, calibration curve, and decision curve analysis (DCA), respectively.

Results

The results of multivariate logistic regression showed that age, body mass index (BMI), previous stroke, diabetes, SII, and SIRI were associated with in-hospital death, and these indicators will be included in the final prediction model, which can be obtained by asking the patient's medical history and blood routine examination in the early stage of admission and can improve the utilization rate of the prediction model. The areas under the ROC curve for the training and validation cohorts nomogram were 0.824 (95% CI 0.796 to 0.851) and 0.809 (95% CI 0.780 to 0.836), respectively. Calibration curves and DCA showed that nomogram could better predict the risk of in-hospital mortality in elderly patients with AMI.

Conclusion

The nomogram constructed by combining SII, SIRI, and partial medical history data (age, BMI, previous stroke, and diabetes) at admission has a good predictive effect on the risk of in-hospital death in elderly patients with AMI.

Perioperative Fluid Management

The medical complexity of the geriatric patients has been steadily rising. Still, as outcomes of surgical procedures in the elderly are improving, centers are pushing boundaries. There is also a growing appreciation of the importance of perioperative fluid management on postoperative outcomes, especially in the elderly. Optimal fluid management in this cohort is challenging due to the combination of age-related physiological changes in organ function, increased comorbid burden, and larger fluid shifts during more complex surgical procedures. The current state-of-the-art approach to fluid management in the perioperative period is outlined.

The change of attention network functions and physiological adaptation during high-altitude hypoxia and reoxygenation

Previous studies have not reached a definitive conclusion regarding the effect of high-altitude hypoxia and reoxygenation on attention. To clarify the influence of altitude and exposure time on attention and the relations between physiological activity and attention, we conducted a longitudinal study to track attention network functions in 26 college students. The scores on the attention network test and physiological data, including heart rate, percutaneous arterial oxygen saturation (SpO₂), blood pressure, and vital capacity in pulmonary function measurement, were collected at five time-points: two weeks before arriving at high altitude (baseline), within 3 days after arriving at high altitude (HA3), 21 days after arriving at high altitude (HA21), 7 days after returning to sea level (POST7) and 30 days after returning to sea level (POST30). The alerting scores at POST30 were significantly higher than those at baseline, HA3 and HA21; the orienting scores at HA3 were lower than those at POST7 and POST30; the executive control scores at POST7 were significantly lower than those at baseline, HA3, HA21, and POST30; and the executive control scores at HA3 were significantly higher than those at POST30. The change in SpO₂ during high-altitude acclimatization (from HA3 to HA21) was positively correlated with the orienting score at HA21. Vital capacity changes during acute deacclimatization positively correlated with orienting scores at POST7. Attention network functions at the behavioral level did not decline after acute hypoxia exposure compared with baseline. Attention network functions after returning to sea level were improved compared with those during acute hypoxia; additionally, alerting and executive function scores were improved compared with those at baseline. Thus, the speed of physiological adaptation could facilitate the recovery of orienting function during acclimatization and deacclimatization.

Acoustic Measures of Voice and Physiologic Measures of Autonomic Arousal During Speech as a Function of Cognitive Load in Older Adults

OBJECTIVES/HYPOTHESIS

The purpose of this study was to determine the relationships among cognitive loading, autonomic arousal, and acoustic measures of voice in healthy older adults.

STUDY DESIGN

Prospective and observational.

METHODS

Twelve healthy older adults (six females) produced a sentence containing an embedded Stroop task in each of two cognitive load conditions: congruent and incongruent. Three physiologic measures of autonomic arousal (pulse volume amplitude, pulse period, and skin conductance response amplitude) and four acoustic measures of voice (cepstral peak prominence, low-to-high spectral energy ratio, fundamental frequency, and sound pressure level) were analyzed in each cognitive load condition.

RESULTS

A logistic regression model was used to predict the cognitive load condition using participant as a categorical predictor and the four acoustic measures and three autonomic measures as continuous predictors. Skin conductance response amplitude and pulse volume amplitude were both predictive of cognitive load; however, no acoustic measures of voice were statistically significant predictors of cognitive load for older adults.

CONCLUSIONS

These findings support the idea that increased cognitive load is associated with increased autonomic nervous system activity in older adults. The lack of changes in acoustic measures of voice with increased cognitive load may result from age-related changes in vocal quality and speech subsystems.

Management of Elderly Asthma: Key Questions and Tentative Answers

The aging lung undergoes structural changes, immunosenescence, and inflammation, rendering the elderly more susceptible to developing obstructive airway disease. Thus, asthma in those of chronological age ≥ 65 years is not rare. Elderly asthma (EA) imposes considerable burdens in terms of mortality and morbidity, and expenditure. However, clinicians lack knowledge of EA and thus often prescribe inappropriate management. In this review, we ask 3 key questions frequently encountered during EA diagnosis and treatment: 1) Is EA different?; 2) How can we appropriately diagnose EA?; 3) Are there management strategies specific to EA? Based on recent studies, we provide tentative answers as follows: 1) late-onset EA differs in clinical features and pathogenetic mechanisms from non-EA, and thus further phenotypic and endotypic characterization of EA is needed; 2) both over- and under-diagnosis of asthma in the elderly can be reduced if the objective diagnostic tests are appropriately performed; 3) cautious prescription of ICS to selected EA patients should be encouraged, and a multifaceted approach which involves increasing medical awareness and inhaler use proficiency and adherence, seeking the assistance of caregivers, and correcting micronutrient deficiencies is required to reduce acute exacerbations in EA patients.

Diagnostic and therapeutic approaches for elderly asthma patients: the importance of multidisciplinary and multidimensional management

INTRODUCTION

Asthma is commonly considered a disease of younger ages; however, it is not infrequent to pose a diagnosis of the disease in older individuals. Although current recommendations do not distinguish between young and old asthmatics in terms of diagnostic and therapeutic approaches, asthma in the elderly may present with peculiar features that contribute to complicate its management.

AREAS COVERED

The current review focuses on the challenges that arise when approaching an older individual with suspected asthma. Age-associated changes of the lung may complicate the diagnostic approach. Measurement of the forced expiratory volume in the first 6 s (FEV6) in an easier and faster alternative to FVC estimation, and residual volume should always be assessed. Older individuals are often affected by concomitant diseases, both age- and drug-related, that need to be considered when approaching elderly asthmatics, since they can affect the efficacy of the treatment as well as the control of the disease.

EXPERT OPINION

The potential drug to drug interaction should be routinely investigated, and documented in medical records. The effect of aging on the response to pharmacological therapy in older asthmatics should be explored. Therefore, the need of a multidisciplinary and multidimensional approach to the elderly asthmatics is strongly encouraged.

Relationship between age, sex and pupillary unrest

Pupllary unrest in ambient light (PUAL) is the chaotic fluctuation of pupil diameter about its mean value. The degree of fluctuation is typically measured using a pupillometer and quantified using an index that sums fluctuations in a frequency range of interest. Indices that measure PUAL show promise in predicting effects of sedative or opioid drugs. Because PUAL is mediated by the parasympathetic nervous system, it would be expected to decline with age-related decreases in parasympathetic tone. In this study we measured average PUAL in 16 subjects from age 3 to 72, with at least 3 repeated measurements on each subject, each taken for approximately 10 s, at approximately 30 frames per second, with illumination of the ipsilateral eye. PUAL was calculated using the algorithm of the Neurolight pupillometer. We found that average PUAL typically declines by approximately 1% per year, and that the standard deviation of repeated measurements is approximately 20%. We therefore conclude that repeated, averaged measurements of age-normed PUAL are likely to be much more clinically useful than single, uncorrected values.

The role of age-associated autonomic dysfunction in inflammation and endothelial dysfunction

Aging of the cardiovascular regulatory function manifests as an imbalance between the sympathetic and parasympathetic (vagal) components of the autonomic nervous system (ANS). The most characteristic change is sympathetic overdrive, which is manifested by an increase in the muscle sympathetic nerve activity (MSNA) burst frequency with age. Age-related changes that occur in vagal nerve activity is less clear. The resting tonic parasympathetic activity can be estimated noninvasively by measuring the increase in heart rate occurring in response to muscarinic cholinergic receptor blockade; animal study models have shown this to diminish with age. Humoral, cellular, and neural mechanisms work together to prevent non-resolving inflammation. This review focuses on the mechanisms underlying age-related alternations in the ANS and how an imbalance in the ANS, evaluated by MSNA and heart rate variability (HRV), potentially facilitates inflammation when the homeostatic mechanisms between reflex neural circuits and the immune system are compromised, particularly the dysfunction of the cholinergic anti-inflammatory reflex. Physiologically, the efferent arm of this reflex acts via the [Formula: see text] 7 nicotinic acetylcholine receptors expressed in macrophages, monocytes, dendritic cells, T cells, and endothelial cells to curb the release of inflammatory cytokines, in which inhibition of NF‑κB nuclear translocation and activation of a JAK/STAT-mediated signaling cascade in macrophages and other immune cells are implicated. This reflex is likely to become less adequate with advanced age. Consequently, a pro-inflammatory state induced by reduced vagus output with age is associated with endothelial dysfunction and may significantly contribute to the development and propagation of atherosclerosis, heart failure, and hypertension. The aim of this review is to summarize the relationship between ANS dysfunction, inflammation, and endothelial dysfunction in the context of aging. Meanwhile, this review also attempts to describe the role of HRV measures as a predictor of the level of inflammation and endothelial dysfunction in the aged population and explore the possible therapeutical effects of vagus nerve stimulation.

Voice biomarkers as indicators of cognitive changes in middle and later adulthood

Voice prosody measures have been linked with Alzheimer's disease (AD), but it is unclear whether they are associated with normal cognitive aging. We assessed relationships between voice measures and 10-year cognitive changes in the MIDUS national sample of middle-aged and older adults ages 42-92, with a mean age of 64.09 (standard deviation = 11.23) at the second wave. Seven cognitive tests were assessed in 2003-2004 (Wave 2) and 2013-2014 (Wave 3). Voice measures were collected at Wave 3 (N = 2585) from audio recordings of the cognitive interviews. Analyses controlled for age, education, depressive symptoms, and health. As predicted, higher jitter was associated with greater declines in episodic memory, verbal fluency, and attention switching. Lower pulse was related to greater decline in episodic memory, and fewer voice breaks were related to greater declines in episodic memory and verbal fluency, although the direction of these effects was contrary to hypotheses. Findings suggest that voice biomarkers may offer a promising approach for early detection of risk factors for cognitive impairment or AD.

Non-contact neuromodulation of the human autonomic nervous system function via different odors: Sex, menstrual cycle, and odor dose- and duration-specific effects

In recent decades, it has been uncovered that the autonomic nervous system (ANS) can be influenced using non-contact neuromodulation via odor stimulation. Increasing parasympathetic-vagal activation of the ANS is integral to improving the sympathovagal balance between the sympathetic- and parasympathetic nervous systems, which is often imbalanced in several chronic inflammatory disorders, such as rheumatoid arthritis and inflammatory bowel diseases. Although research into olfactory stimulation has been observed on the ANS, it is still lacking in the exploration of odor concentration and odor-specific effects. This is particularly the case as research has not utilized specified tools, such as the olfactometer to provide precise odor delivery. Furthermore, no research has compared the results in separate sex cohorts to investigate the role of sex or the menstrual stage on the subsequent interactions. In this study, we investigated the olfactory stimulation effects of four natural odors (mushroom, lavender, jasmine, and rose) in three concentrations (low, moderate, and high) on the ANS. To observe activity from the ANS, we used an electrocardiogram (ECG) based heart rate variability (HRV) and eye-tracker technology (pupil diameter). We found for the first time in literature that there were acute dose- and duration-specific odor effects of odors on the ANS. We also found sex and menstrual cycle effects in this interaction. Furthermore, there were stark distinctions in sympathovagal activity dependent ANS activation (HRV) in comparison to the oculomotor nerve-parasympathetic/cervical sympathetic nerves dependent ANS responses (pupil diameter). Sympathovagal activity dependent HRV showed odor, sex, and menstrual-stage interactions in both divisions of the ANS while the pupil responses only indicated increased sympathetic activation. These results shed light on the use of odor-specific stimulation to modulate the ANS activity in the context of sex and the menstrual stage. Future studies should be performed using a chronic odor delivery design to investigate the long-term effects of odors on the ANS.

Exercise as an Aging Mimetic: A New Perspective on the Mechanisms Behind Exercise as Preventive Medicine Against Age-Related Chronic Disease

Age-related chronic diseases are among the most common causes of mortality and account for a majority of global disease burden. Preventative lifestyle behaviors, such as regular exercise, play a critical role in attenuating chronic disease burden. However, the exact mechanism behind exercise as a form of preventative medicine remains poorly defined. Interestingly, many of the physiological responses to exercise are comparable to aging. This paper explores an overarching hypothesis that exercise protects against aging/age-related chronic disease because the physiological stress of exercise mimics aging. Acute exercise transiently disrupts cardiovascular, musculoskeletal, and brain function and triggers a substantial inflammatory response in a manner that mimics aging/age-related chronic disease. Data indicate that select acute exercise responses may be similar in magnitude to changes seen with +10-50 years of aging. The initial insult of the age-mimicking effects of exercise induces beneficial adaptations that serve to attenuate disruption to successive "aging" stimuli (i.e., exercise). Ultimately, these exercise-induced adaptations reduce the subsequent physiological stress incurred from aging and protect against age-related chronic disease. To further examine this hypothesis, future work should more intricately describe the physiological signature of different types/intensities of acute exercise in order to better predict the subsequent adaptation and chronic disease prevention with exercise training in healthy and at-risk populations.

Assessment of arteriosclerosis based on multiscale cross approximate entropy of human finger pulse wave

BACKGROUND: Arteriosclerosis is one of the diseases that endanger human health. There is a large amount of information in pulse wave signals to reflect the degree of arteriosclerosis. OBJECTIVE: The degree of arteriosclerosis is assessed by analyzing pulse wave signal and calculating multi-scale entropy values. METHODS: A method based on the multiscale cross-approximate entropy of the pulse wave of the human finger is proposed to assess the degree of arteriosclerosis. A total of 86 subjects were divided into three groups. The data of 1000 pulse cycles were selected in the experiment, and the multiscale cross-approximate entropy was calculated for the climb time and pulse wave peak interval. Independent sample t-test analysis gives the small-scale cross-approximate entropy of the two time series of climb time and pulse wave peak interval as p< 0.001 in Groups 1 and 2. The large-scale cross-approximate entropy of the two time series of climb time and pulse wave peak interval is p< 0.017 in Groups 2 and 3. RESULTS: Using the proposed algorithm, the results showed that the small-scale cross-approximate entropy of climb time and pulse wave peak interval could reflect the degree of arteriosclerosis in the human body from the perspective of autonomic nerve function. The large-scale cross-approximate entropy of climb time and pulse wave peak interval confirmed the effect of diabetes on the degree of arteriosclerosis. CONCLUSIONS: The results demonstrate the multiscale cross-approximate entropy is a comprehensive index to evaluate the degree of human arteriosclerosis.

Heart Rate Variability in Hyperthyroidism: A Systematic Review and Meta-Analysis

Objective: Cardiovascular effects of thyroid hormones may be measured through heart rate variability (HRV). We sought to determine the impact of hyperthyroidism on HRV. Design: A systematic review and meta-analysis on the impact of hyperthyroidism on HRV. Methods: PubMed, Cochrane, Embase and Google Scholar were searched until 20 August 2021 for articles reporting HRV parameters in untreated hyperthyroidism and healthy controls. Random-effects meta-analysis was stratified by degree of hyperthyroidism for each HRV parameter: RR intervals (or Normal-to-Normal intervals—NN), SDNN (standard deviation of RR intervals), RMSSD (square root of the mean difference of successive RR intervals), pNN50 (percentage of RR intervals with >50 ms of variation), total power (TP), LFnu (low-frequency normalized unit) and HFnu (high-frequency), VLF (very low-frequency), and LF/HF ratio. Results: We included 22 studies with 10,811 patients: 1002 with hyperthyroidism and 9809 healthy controls. There was a decrease in RR (effect size = −4.63, 95% CI −5.7 to −3.56), SDNN (−6.07, −7.42 to −4.71), RMSSD (−1.52, −2.18 to −0.87), pNN50 (−1.36, −1.83 to −0.88), TP (−2.05, −2.87 to −1.24), HFnu (−3.51, −4.76 to −2.26), and VLF power (−2.65, −3.74 to −1.55), and an increase in LFnu (2.66, 1.55 to 3.78) and LF/HF ratio (1.75, 1.02 to 2.48) (p < 0.01). Most parameters had ES that was twice as high in overt compared to subclinical hyperthyroidism. Increased peripheral thyroid hormones and decreased TSH levels were associated with lower RR intervals. Conclusions: Hyperthyroidism is associated with a decreased HRV, which may be explained by the deleterious effect of thyroid hormones and TSH. The increased sympathetic and decreased parasympathetic activity may have clinical implications.

The Effects of Heart Rate Variability (HRV) Biofeedback on HRV Reactivity and Recovery During and After Anger Recall Task for Patients with Coronary Artery Disease

Patients with coronary artery disease (CAD) often experience anger events before cardiovascular events. Anger is a psychological risk factor and causes underlying psychophysiological mechanisms to lose balance of the autonomic nervous system (ANS). The heart rate variability (HRV) was the common index for ANS regulation. It has been confirmed that heart rate variability biofeedback (HRV-BF) restored ANS balance in patients with CAD during the resting state. However, the effects of HRV-BF during and after the anger event remain unknown. This study aimed to examine the effects of HRV-BF on ANS reactivity and recovery during the anger recall task in patients with CAD. This study was a randomized control trial with a wait-list control group design, with forty patients in the HRV-BF group (for six sessions) and 44 patients in the control group. All patients received five stages of an anger recall task, including baseline, neutral recall task, neutral recovery, anger recall task, and anger recovery. HRV reactivity in the HRV-BF group at the post-test was lower than that in the control group. HRV recovery at the post-test in the HRV-BF group was higher than that in the control group. The HRV-BF reduced ANS reactivity during anger events and increased ANS recovery after anger events for CAD patients. The possible mechanisms of HRV-BF may increase total HRV, ANS regulation, and baroreflex activation at anger events for patients with CAD, and may be a suitable program for cardiac rehabilitation.

Age-related tilt test responses in patients with suspected reflex syncope

AIMS

Tilt testing (TT) is recognized to be a valuable contribution to the diagnosis and the pathophysiology of vasovagal syncope (VVS). This study aimed to assess the influence of age on TT responses by examination of a large patient cohort.

METHODS AND RESULTS

Retrospective data from three experienced European Syncope Units were merged to include 5236 patients investigated for suspected VVS by the Italian TT protocol. Tilt testing-positivity rates and haemodynamics were analysed across age-decade subgroups. Of 5236 investigated patients, 3129 (60%) had a positive TT. Cardioinhibitory responses accounted for 16.5% of positive tests and were more common in younger patients, decreasing from the age of 50-59 years. Vasodepressor (VD) responses accounted for 24.4% of positive tests and prevailed in older patients, starting from the age of 50-59. Mixed responses (59.1% of cases) declined slightly with increasing age. Overall, TT positivity showed a similar age-related trend (P = 0.0001) and was significantly related to baseline systolic blood pressure (P < 0.001). Tilt testing was positive during passive phase in 18% and during nitroglycerine (TNG)-potentiated phase in 82% of cases. Positivity rate of passive phase declined with age (P = 0.001), whereas positivity rate during TNG remained quite stable. The prevalence of cardioinhibitory and VD responses was similar during passive and TNG-potentiated TT, when age-adjusted.

CONCLUSIONS

Age significantly impacts the haemodynamic pattern of TT responses, starting from the age of 50. Conversely, TT phase-passive or TNG-potentiated-does not significantly influence the type of response, when age-adjusted. Vagal hyperactivity dominates in younger patients, older patients show tendency to vasodepression.

Aging is associated with cardiac autonomic nerve fiber depletion and reduced cardiac and circulating BDNF levels

BACKGROUND

Aging is a multifactorial process associated with an impairment of autonomic nervous system (ANS) function. Progressive ANS remodeling includes upregulation of expression of circulating catecholamines and depletion of cardiac autonomic nerve fibers, and it is responsible, in part, for the increased susceptibility to cardiac diseases observed in elderly subjects. Neurotrophic factors, such as brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF), are involved in synaptogenesis and neurite outgrowth processes, supporting neuronal cell differentiation and maturation. However, whether and how these factors and their downstream signaling are involved in cardiac aging remains unclear. Here, we tested whether, in the aged heart, the overall extent of autonomic fibers is reduced, owing to lower production of trophic factors such as BDNF and NGF.

METHODS

In vivo, we used young (age: 3 months; n = 10) and old (age: 24 months; n = 11) male Fisher rats, whereas, we used human neuroblastoma (SH-SY5Y) cells in vitro.

RESULTS

Compared to the young rats, old rats displayed a marked reduction in the overall ANS fiber density, affecting both sympathetic and cholinergic compartments, as indicated by dopamine β-hydroxylase (dβh) and vesicular acetylcholine transporter (VaChT) immunohistochemical staining. In addition, a marked downregulation of GAP-43 and BDNF protein was observed in the left ventricular lysates of old rats compared to those of young rats. Interestingly, we did not find any significant difference in cardiac NGF levels between the young and old groups. To further explore the impact of aging on ANS fibers, we treated SH-SY5Y cells in vitro with serum obtained from young and old rats. Sera from both groups induced a remarkable increase in neuronal sprouting, as evidenced by a crystal violet assay. However, this effect was blunted in cells cultured with old rat serum and was accompanied by a marked reduction in GAP-43 and BDNF protein levels.

CONCLUSIONS

Our data indicate that physiological aging is associated with an impairment of ANS structure and function and that reduced BDNF levels are responsible, at least in part, for these phenomena.

Analysis of the side effect of QTc interval prolongation in the bedaquiline regimen in drug resistant tuberculosis patients

OBJECTIVES

Indonesia is one of the top 20 countries with the highest prevalence of drug resistant tuberculosis (DR-TB) worldwide with a percentage of new cases of 2.4% and retreatment of 13%. Bedaquiline (BDQ) is one of the drugs that used in the individual long regimen treating DR-TB. BDQ is also combined with levofloxacin (LFX) and/or clofazimine (CFZ) that can cause QTc interval prolongation. The aim was to study the differences in the use of BDQ regimens to the lengthening of the QTc interval and to study risk factors (diabetes, hypokalemia, sex, BMI, and age) in BDQ regimen.

METHODS

This study was an observational retrospective study with a total sampling method, which was conducted at Dr. Soetomo General Hospital Surabaya. Samples from this study were patients diagnosed with DR-TB at Dr. Soetomo General Hospital Surabaya in the period of January 2015-December 2019 who used BDQ regimen and met the inclusion criteria. The ECG data were analyzed from the mean of each group (BDQ regimen and risk factors), also analyzed using statistical analysis.

RESULTS

Data obtained from total sample in this study were 73 patients. The most widely used different regimens in this study were the combination of BDQ + LFX by 36 patients (49.3%), BDQ + LFX + CFZ by 16 patients (21.9%), BDQ by 11 patients (15.1%) and BDQ + CFZ 10 patients (13.7%). Out of 73 patients, 52 patients (71.2%) experienced lengthening of the QT interval and grade 1 of QTc interval prolongation occurred in most patients and also the onset was mostly one month after using BDQ regimen. The side effects of QTc interval prolongation from groups of combination and risk factors were no difference in each month (p>0.05).

CONCLUSIONS

This study can be concluded that there were no differences in the QTc prolongation between the groups of BDQ regimen (BDQ, BDQ + LFX, BDQ + CFZ and BDQ + LFX + CFZ) and the groups of risk factors.

Age-Related Changes in Cardiac Autonomic Modulation and Heart Rate Variability in Mice

Objective

The aim of this study was to assess age-related changes in cardiac autonomic modulation and heart rate variability (HRV) and their association with spontaneous and pharmacologically induced vulnerability to cardiac arrhythmias, to verify the translational relevance of mouse models for further in-depth evaluation of the link between autonomic changes and increased arrhythmic risk with advancing age.

Methods

Heart rate (HR) and time- and frequency-domain indexes of HRV were calculated from Electrocardiogram (ECG) recordings in two groups of conscious mice of different ages (4 and 19 months old) (i) during daily undisturbed conditions, (ii) following peripheral β-adrenergic (atenolol), muscarinic (methylscopolamine), and β-adrenergic + muscarinic blockades, and (iii) following β-adrenergic (isoprenaline) stimulation. Vulnerability to arrhythmias was evaluated during daily undisturbed conditions and following β-adrenergic stimulation.

Results

HRV analysis and HR responses to autonomic blockades revealed that 19-month-old mice had a lower vagal modulation of cardiac function compared with 4-month-old mice. This age-related autonomic effect was not reflected in changes in HR, since intrinsic HR was lower in 19-month-old compared with 4-month-old mice. Both time- and frequency-domain HRV indexes were reduced following muscarinic, but not β-adrenergic blockade in younger mice, and to a lesser extent in older mice, suggesting that HRV is largely modulated by vagal tone in mice. Finally, 19-month-old mice showed a larger vulnerability to both spontaneous and isoprenaline-induced arrhythmias.

Conclusion

The present study combines HRV analysis and selective pharmacological autonomic blockades to document an age-related impairment in cardiac vagal modulation in mice which is consistent with the human condition. Given their short life span, mice could be further exploited as an aged model for studying the trajectory of vagal decline with advancing age using HRV measures, and the mechanisms underlying its association with proarrhythmic remodeling of the senescent heart.

PR interval as a predictor of syncope in tilt-up testing in adolescents and young adults

BACKGROUND

Syncope, as the most frequent consciousness disorder, is very common in young individuals. The aim of this study was to analyze ECG parameters and clinical properties obtained during tilt-up testing in 12 to 30-year-old subjects. We enrolled a total of 142 patients from our outpatient clinic (39 males, 103 females) with a true positive tilt-up test and analyzed ECG records obtained during tilt-testing. Data were stratified according to the age, gender, and type of syncope.

RESULTS

PR interval shortening preceding syncope was found in all syncope types, irrespective of the gender. All types of syncope were more frequent in women (72.5%). Mixed syncope type was found to be the most common (47.18%). Male and female subjects differed in initial heart rate (71.56 vs 76.23/min, p=0.05), as well as heart rate dynamics during tilt-up testing. A gender difference was also found in systolic blood pressure (116.92 vs 110.44 mmHg, p<0.01), time to syncope onset (20.77 vs. 16.44 min, p=0.03), and the total number of syncopal episodes in patient history (2.79 vs. 4.62, p<0.05). Subjects with cardioinhibitory syncope had the longest PR interval (average 154.3 ms). PR interval prolongation and loss of variability during tilt-up testing positively correlated with aging (r=0.22, p<0.05). Nodal rhythm was found in 8 patients.

CONCLUSION

PR interval shortening on ECG tracings during a tilt-up test can be found in all subtypes of vasovagal syncope, thereby contrasting previous reports that these changes are a hallmark of the cardioinhibitory type of syncope. PR shortening, if observed during ECG monitoring, could be a potential predictor of syncope.

Progress in the risk assessment of hydroxychloroquine in frail elderly people

Hydroxychloroquine (HCQ) is an antimalarial drug also known to have anti-inflammatory and antiviral effects. The antiviral action of HCQ has been a point of interest for many researchers because of its mechanism of action and the potential use it could have during the current COVID-19 pandemic. However, HCQ can cause QT interval prolongation. The current therapies used in COVID-19 are changing as the pandemic develops. The aim of this article is to promote a validated risk score for QT prolongation in multidimensional assessment of COVID-19 patients, especially in elderly and polypathological patients.

Association of blood pressure and BMI to corrected QT interval in young adults

Hypertension is often associated with obesity. Uncontrolled hypertension can lead to uncorrected cardiac dysautonomia that makes cardiac repolarization abnormally prolonged. Modern dietary habits, stress, and bad lifestyle habits make young adults vulnerable to hazards of health. We planned to study the association of body mass index (BMI) and blood pressure (BP) with corrected QT (QTc) intervals in young adults. After obtaining the written informed consent, 171 subjects were randomly selected in the age group of 18-35 years. A general history and physical examination were done before recording the BMI and BP. A 12-lead electrocardiogram was recorded and QTc calculated using Bazett's formula. The values obtained were compared and statistical analysis done. Of the 171 subjects 14.03% were hypertensive. The QTc interval was found to be prolonged in females and it is prolonged with age, BMI, and BP. QTc was significantly increased among the prehypertensive and hypertensive group and with the overweight and (or) obese BMI group compared with the normotensives and normal BMI group suggesting an altered autonomic homeostasis. This warrants lifestyle modification at a younger age to reduce the cardiovascular risk.

Caloric restriction reduces sympathetic activity similar to beta-blockers but conveys additional mitochondrio-protective effects in aged myocardium

Increased activation of sympathetic nervous system contributes to congestive heart failure (CHF) progression, and inhibition of sympathetic overactivation by beta-blockers is successful in CHF patients. Similarly, caloric restriction (CR) reduces sympathetic activity but mediates additional effects. Here, we compared the cardiac effects of CR (− 40% kcal, 3 months) with beta-blocker therapy (BB), diuretic medication (DF) or control diet in 18-months-old Wistar rats. We continuously recorded blood pressure, heart rate, body temperature and activity with telemetric devices and analysed cardiac function, activated signalling cascades and markers of apoptosis and mitochondrial biogenesis. During our study, left ventricular (LV) systolic function improved markedly (CR), mildly (BB) or even deteriorated (DF; control). Diastolic function was preserved by CR and BB but impaired by DF. CR reduced blood pressure identical to DF and BB and heart rate identical to BB. Plasma noradrenaline was decreased by CR and BB but increased by DF. Only CR reduced LV oxidative damage and apoptosis, induced AMPK and Akt phosphorylation and increased mitochondrial biogenesis. Thus, additive to the reduction of sympathetic activity, CR achieves protective effects on mitochondria and improves LV function and ROS damage in aged hearts. CR mechanisms may provide additional therapeutic targets compared to traditional CHF therapy.

Declining Trends of Heart Rate Variability According to Aging in Healthy Asian Adults

Heart rate variability (HRV) indices correlate with aging and are related to the autonomic nervous system. However, the trend of HRV with age has not been explored for the Asian population. Therefore, we proposed a linear regression model of HRV indices that decreased with aging in healthy Asian adults. HRV parameters [High frequency (HF), Low frequency (LF), Very low frequency (VLF), Total power (TP), HRV triangular index (HRV-index), Standard deviation of the normal-to-normal interval (SDNN), and Proportion of normal-to-normal intervals greater than 50 ms (pNN50)] were measured in a total of 300 healthy participants (150 men and 150 women) aged 19-69 years stratified into five age groups: 19-29, 30-39, 40-49, 50-59, and 60-69 years comprising 60 people each in Seoul, South Korea. A simple regression analysis was performed to reveal the linear declining trend of HRV indices with age. Independent t-tests were conducted to investigate the gender differences in HRV values depending on each age group. The values of all HRV indices showed a decreasing trend with age in healthy Korean adults, as observed in the Western population (P < 0.001 for all indices); HF (Y = -0.039x + 6.833, R 2 = 0.287), LF (Y = -0.047x + 7.197, R 2 = 0.414), VLF (Y = -0.025x + 6.861, R 2 = 0.177), TP (Y = -0.034x + 8.082, R 2 = 0.352), HRV-index (Y = -0.125x + 15.628, R 2 = 0.298), SDNN (Y = -0.502x + 53.907, R 2 = 0.343), and pNN50 (Y = -0.650x + 53.852, R 2 = 0.345) all decreased with age. There was no significant gender difference in any HRV parameter. A linear regression model of various HRV indices has been presented considering the age of healthy Asians, which may be useful to prevent diseases related to the autonomic nervous system by estimating or tracking autonomic functional degeneration in the Asian population.

Assessing cognitive load in adolescent and adult students using photoplethysmogram morphometrics

Compared to cardiac parameters and skin conductivities, the photoplethysmogram (PPG) recorded at fingertips and other parts near to peripheral nerve ends have been recently revealed to be yet another sensitive measure for cognitive load assessment. However, there is so far no research on measuring adolescents' cognitive load using physiological signals. A comprehensive study on the effects of PPG morphometrics over a cohort covering both adolescent and adult students is also absent. In this study, we analyze the morphological features of PPG on cognitive load assessment and compare them between adolescent and adult students. Experiments on two-level arithmetic tasks show that the PPG morphometrics reached the same level of significance on the effect of task difficulty/period as heart rate, and different morphological behaviors were also shown between adolescent and adult students during the cognitive task effects, which may imply their physiological differences across age. Physiological signals recorded by wearable devices are also found to be effective in measuring cognitive load.

Impact of age and sex on neural cardiovascular responsiveness to cold pressor test in humans

Prior longitudinal work suggests that blood pressure (BP) reactivity to the cold pressor test (CPT) helps predict hypertension; yet the impact of age and sex on hemodynamic and neural responsiveness to CPT remains equivocal. Forty-three young (21 ± 1yr, means ± SE) men (YM, n = 20) and women (YW, n = 23) and 16 older (60 ± 1yr) men (OM, n = 9) and women (OW, n = 7) participated in an experimental visit where continuous BP (finger plethysmography) and muscle sympathetic nerve activity (MSNA; microneurography) were recorded during a 3- to 5-min baseline and 2-min CPT. Baseline mean arterial pressure (MAP) was greater in OM than in YM (92 ± 4 vs. 77 ± 1 mmHg, P < 0.01), but similar in women (P = 0.12). Baseline MSNA incidence was greater in OM [69 ± 6 bursts/100 heartbeats (hb)] than in OW (44 ± 7 bursts/100 hb, P = 0.02) and lower in young adults (YM: 17 ± 3 vs. YW: 16 ± 2 bursts/100 hb, P < 0.01), but similar across the sexes (P = 0.83). However, when exposed to the CPT, MSNA increased more rapidly in OW (Δ43 ± 6 bursts/100 hb; group × time, P = 0.01) compared with OM (Δ15 ± 3 bursts/100 hb) but was not different between YW (Δ30 ± 3 bursts/100 hb) and YM (Δ33 ± 4 bursts/100 hb, P = 1.0). There were no differences in MAP with CPT between groups (group × time, P = 0.33). These findings suggest that OW demonstrate a more rapid initial rise in MSNA responsiveness to a CPT compared with OM. This greater sympathetic reactivity in OW may be a contributing mechanism to the increased hypertension risk in postmenopausal women.

Is there a relationship between epicardial fat tissue thickness and Tp-Te/QT ratio in healthy individuals?

Introduction

Epicardial fat is a tissue that releases many proinflammatory and atherogenic mediators, with endocrine and paracrine effects on the heart. In this study, the implication of the EFT thickness (EFTt) on transmural dispersion of repolarisation (TDR) was analysed utilizing the T-wave peak to end interval (Tp-Te), the Tp-Te dispersion (Tp-Te (d)), and the Tp-Te/QT ratio.

Material and methods

One thousand seven hundred and thirteen subjects were enrolled in the research. The subjects were chosen to be healthy individuals, without any cardiovascular/systemic disorders or risk factors for atherosclerosis. Transthoracic echocardiography (TTE) was applied to all subjects, and EFTt was measured in both diastole and systole. The ECG measurements were taken from standard 12-lead surface ECG.

Results

Correlation analysis revealed that the EFTt is highly associated with the Tp-Te interval, Tp-Te/QT ratio, Tp-Te (d), increasing age, body mass index (BMI), body surface area (BSA), left ventricular (LV) mass, LV mass index, plasma glucose during fasting, triglycerides, and low-density lipoprotein cholesterol.

Conclusions

The study results showed that increased EFTt was associated with increased TDR values of Tp-Te, Tp-Te (d), and Tp-Te/QT ratio, even in the absence of other factors that could increase TDR and EFTt. Therefore, it can be stated that increased EFTt may cause an increase the risk for ventricular arrhythmia.

Post-ictal accelerometer silence as a marker of post-ictal immobility

OBJECTIVE

Movement-based wearable sensors are used for detection of convulsive seizures. The identification of the absence of motion following a seizure, known as post-ictal immobility (PI), may represent a potential additional application of wearables. PI has been associated with potentially life-threatening complications and with sudden unexpected death in epilepsy (SUDEP). We aimed to assess whether wearable accelerometers (ACCs) could be used as a digital marker of PI.

METHOD

Devices with embedded ACCs were worn by patients admitted to an epilepsy monitoring unit. Participants presenting with convulsive seizures were included in the study. PI presence and duration were assessed by experts reviewing video recordings. An algorithm for the automatic detection of post-ictal ACC silence and its duration was developed and the linear pairwise relationship between the automatically detected duration of post-ictal ACC silence and the duration of the expert-labeled PI was analyzed.

RESULTS

Twenty-two convulsive seizures were recorded from 18 study participants. Twenty were followed by PI and two by agitation. The automated estimation of post-ictal ACC silence identified all the 20 expert-labeled PI. The regression showed that the duration of the post-ictal ACC silence was correlated with the duration of PI (Pearson r = .92; P < .001), with the age of study participants (Pearson r = .78; P < .001), and with the duration of post-ictal generalized electroencephalography suppression (PGES; Pearson r = .4; P = .033).

SIGNIFICANCE

We highlight a novel application of wearables as a way to record post-ictal manifestations associated with an increased risk of SUDEP. The occurrence of a fatal seizure is unpredictable and the continuous, non-invasive, long-term identification of risk factors associated with each individual seizure may assume a great clinical importance.

Time for a Systems Biological Approach to Cognitive Aging?-A Critical Review

The underlying premise of current theories of cognitive decline with age tend to be primarily cognitive or biological explanations, with relatively few theories adequately integrating both aspects. Though literature has also emphasized the importance of several factors that contribute to cognitive aging including: (a) decline in sensory abilities; (b) the effect of motor speed on paper-pencil measures of cognitive speed; (c) the impact of level of education and physical activity; and (d) molecular biological changes that occur with age, these factors have seldom been implicated into any single theoretical model of cognitive aging. Indeed, such an integrated bio-cognitive model of aging has the potential to provide a more comprehensive understanding of attention, perception, learning, and memory across the lifespan. Thus, the aim of this review was to critically evaluate common theories of age-related cognitive decline and highlight the need for a more comprehensive systems neuroscience approach to cognitive aging.

Neighborhood crime risk and resting respiratory sinus arrhythmia in middle childhood: Evidence of gender differences

Although there is a robust link between resting respiratory sinus arrhythmia (RSA), a biological marker of emotion regulation, and risk for psychopathology, the factors that may be associated with aberrant RSA development remain unclear. The goal of the current study was to examine the relation between children's resting levels of RSA and neighborhood crime, a macro-level environmental stressor associated with increased risk for multiple forms of psychopathology in youth. The levels of neighborhood crime were obtained using a geocoded neighborhood crime exposure database, allowing for the objective assessment of the likelihood of crime occurring in the child's community. The results indicated that the relation between neighborhood crime and resting RSA differed for girls and boys such that living in a neighborhood with higher risk of exposure to violent crimes was associated with lower RSA for girls, but not boys. These results suggest that living in a higher crime neighborhood is associated with an objective, biologically-based marker of emotion regulation and highlight how neighborhood crime may be specifically associated with risk for girls.

Sex-related differences in sudomotor function in healthy early twenties focused on activated sweat gland density

The purpose of this study was to quantitatively assess the difference in sudomotor function between healthy males and females in their early twenties by measuring skin surface area and activated sweat gland density (ASGD). The quantitative sudomotor axon reflex test (QSART), a method for evaluating autonomic nervous system activity, was used for quantification. In QSART, the sweat glands are activated directly or indirectly by the subcutaneous application of neurotransmitters, such as acetylcholine, through iontophoresis. This series of mechanisms is called the sudomotor axon reflex. After recording age, height, weight, and several measurements of the forearm, QSART was performed on 101 healthy controls aged 21-26 years to measure ASGD. The mean temperature and humidity on the measurement days were 11.4°C and 58.1% on May 3, 2018, and 14.7°C and 70.3% on May 10, 2018. The result of independent sample t-test showed higher ASGD in women (P < 0.05). The body surface area and the surface area of the forearms were higher in men (P < 0.001), but the number of activated sweat glands was not significantly different according to sex. The activated sweat gland counts of the body and forearms were analyzed through linear regression by age for males and females. Except for the activated sweat gland count of the male body, the analysis showed a tendency to decrease with increasing age but was not statistically significant in any case (P > 0.05). Showing insufficient coefficient of determination (R²), multiple regression analyses with sex and ages did not correct this insignificance between age and activated sweat gland count.

Obesity-induced sympathoexcitation is associated with Nrf2 dysfunction in the rostral ventrolateral medulla

Increases in sympathetic nerve activity (SNA) have been implicated in obesity-induced risk for cardiovascular diseases, especially hypertension. Previous studies indicate that oxidative stress in the rostral ventrolateral medulla (RVLM), a key brain stem region that regulates sympathetic outflow to peripheral tissues, plays a pathogenic role in obesity-mediated sympathoexcitation. However, the molecular mechanisms underlying this phenomenon are not clear. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a transcription factor that regulates the expression of antioxidant and anti-inflammatory genes and confers cytoprotection against oxidative stress. The present study was designed to investigate whether Nrf2 dysfunction was associated with obesity-induced oxidative stress in the RVLM and sympathoexcitation. C57BL/6J mice were fed with chow or a high-fat diet (HFD) for 16 wk. Blood pressure parameters were assessed by radiotelemeters in conscious freely moving mice. SNA was measured by heart rate variability analysis and also through assessment of depressor response to ganglionic blockade. The RVLM was microdissected for gene expression and protein analysis (Western blot analysis and activity assay) related to Nrf2 signaling. Our results showed that HFD-induced obesity resulted in significant increases in SNA, although we only observed a mild increase in mean arterial pressure. Obesity-induced oxidative stress in the RVLM was associated with impaired Nrf2 signaling marked by decreased Nrf2 activity, downregulation of Nrf2 mRNA, its target genes [NAD(P)H quinone dehyrogenase 1 (Nqo1) and superoxide dismutase 2 (Sod2)], and inflammation. Our findings suggest that obesity results in Nrf2 dysfunction, which likely causes maladaptation to oxidative stress and inflammation in the RVLM. These mechanisms could potentially contribute to obesity-induced sympathoexcitation.

Autonomic nervous system response to remote ischemic conditioning: heart rate variability assessment

Background

Remote ischemic conditioning (RIC) is a procedure applied in a limb for triggering endogenous protective pathways in distant organs, namely brain or heart. The underlying mechanisms of RIC are still not fully understood, and it is hypothesized they are mediated either by humoral factors, immune cells and/or the autonomic nervous system. Herein, heart rate variability (HRV) was used to evaluate the electrophysiological processes occurring in the heart during RIC and, in turn to assess the role of autonomic nervous system.

Methods

Healthy subjects were submitted to RIC protocol and electrocardiography (ECG) was used to evaluate HRV, by assessing the variability of time intervals between two consecutive heart beats. This is a pilot study based on the analysis of 18 ECG from healthy subjects submitted to RIC. HRV was characterized in three domains (time, frequency and non-linear features) that can be correlated with the autonomic nervous system function.

Results

RIC procedure increased significantly the non-linear parameter SD2, which is associated with long term HRV. This effect was observed in all subjects and in the senior (> 60 years-old) subset analysis. SD2 increase suggests an activation of both parasympathetic and sympathetic nervous system, namely via fast vagal response (parasympathetic) and the slow sympathetic response to the baroreceptors stimulation.

Conclusions

RIC procedure modulates both parasympathetic and sympathetic autonomic nervous system. Furthermore, this modulation is more pronounced in the senior subset of subjects. Therefore, the autonomic nervous system regulation could be one of the mechanisms for RIC therapeutic effectiveness.

Electronic supplementary material

The online version of this article (10.1186/s12872-019-1181-5) contains supplementary material, which is available to authorized users.

Cardiac 11C-Donepezil Binding Increases With Age in Healthy Humans: Potentially Signifying Sigma-1 Receptor Upregulation

BACKGROUND

Donepezil may have cardioprotective properties, but the mechanism is unclear. Using positron-emission tomography (PET), we explored 11C-donepezil uptake in the heart of humans in relation to age. The results are discussed in the context of the cardioprotective property of donepezil.

METHODS

We included data from 57 patients with cardiac 11C-donepezil PET scans. Linear regression analyses were performed to explore the correlation between cardiac 11C-donepezil standardized uptake value (SUV) and age. Subgroup analyses were performed for healthy controls, patients with prodromal or diagnosed Parkinson disease (PD), males, and females.

RESULTS

In the total group of 57 patients, linear regression analysis revealed a significant positive correlation between cardiac 11C-donepezil uptake and age ( r2 = .63, P < .0001). The average increase was ≈1.25 SUV per decade and a 2-fold increase in SUV from age 30 to 65 years. Subgroup analyses also showed significant correlations: healthy control patients alone (n = 28, r2 = .73, P < .0001), prodromal or diagnosed PD (n = 29, r2 = .28, P = .03), male patients (n = 34, r2 = .49, P < .0001), and female patients (n = 23, r2 = .82, P < .0001). No other organs showed increased 11C-donepezil binding with age.

CONCLUSIONS

11C-donepezil SUV increases robustly with age in the normal human heart. We speculate that the increased donepezil binding is caused primarily by sigma-1 receptor upregulation. If our interpretation is correct, it shows that sigma-1 receptors are dynamically regulated and may represent an overlooked target for pharmacological intervention studies.

Comparison of autonomic stress reactivity in young healthy versus aging subjects with heart disease

BACKGROUND

The autonomic response to acute emotional stress can be highly variable, and pathological responses are associated with increased risk of adverse cardiovascular events. We evaluated the autonomic response to stress reactivity of young healthy subjects and aging subjects with coronary artery disease to understand how the autonomic stress response differs with aging.

METHODS

Physiologic reactivity to arithmetic stress in a cohort of 25 young, healthy subjects (< 30 years) and another cohort of 25 older subjects (> 55 years) with CAD was evaluated using electrocardiography, impedance cardiography, and arterial pressure recordings. Stress-related changes in the pre-ejection period (PEP), which measures sympathetic activity, and high frequency heart rate variability (HF HRV), which measures parasympathetic activity, were analyzed as primary outcomes.

RESULTS

Mental stress reduced PEP in both groups (p<0.01), although the decrease was 50% greater in the healthy group. Mean HF HRV decreased significantly in the aging group only (p = 0.01).

DISCUSSION

PEP decreases with stress regardless of health and age status, implying increased sympathetic function. Its decline with stress may be attenuated in CAD. The HF HRV (parasympathetic) stress reactivity is more variable and attenuated in younger individuals; perhaps this is related to a protective parasympathetic reflex.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02657382.

Primary headaches during lifespan

Primary headaches are one of the most prevalent neurological disorders and can occur during a wide range of lifespan. Primary headaches, especially migraine, are cyclic disorders with a complex sequence of symptoms within every headache attack. There is no systematic review of whether these symptoms changes during lifespan. Indeed, the clinical presentation of migraine shows an age-dependent change with a significantly shorter duration of the attacks and occurrence of different paroxysmal symptoms, such as vomiting, abdominal pain or vertigo, in childhood and, in contrast, largely an absence of autonomic signs and a more often bilateral headache in the elderly. The age-dependent differences in the clinical presentation are less distinct in cluster headache and, especially, in tension-type headache. The differences in the clinical presentation are in agreement with the idea that the connectivity of hypothalamic areas with different brainstem areas, especially the central parasympathetic areas, is important for the clinical manifestation of migraine, as well as, the change during lifespan.

Clinical factors associated with the recovery of cardiovascular autonomic neuropathy in patients with type 2 diabetes mellitus

Background

Cardiovascular autonomic neuropathy (CAN) is a major cause of morbidity and mortality in diabetes patients. Although several risk factors for CAN progression have been established, whether CAN is reversible remains unclear and the clinical factors associated with CAN recovery have not been identified. This study aimed to determine clinical factors related to CAN recovery.

Methods

Type 2 diabetes patients with CAN but free of cardiovascular disease at baseline were enrolled and followed for 2–3 years in this retrospective longitudinal study. CAN was classified as early (one abnormal parasympathetic test), definite (two or more abnormal parasympathetic tests), severe (definite plus orthostatic hypotension), or atypical (early plus orthostatic hypotension or orthostatic hypotension alone) based on Ewing’s method. CAN recovery was classified as partial or complete: Partial recovery was defined as one-step improvement in CAN stage (early to normal, definite to early, or severe to definite), including the disappearance of only one abnormal result in any stage. Complete recovery was defined as normalization from definite or severe CAN.

Results

Among 759 subjects with CAN, 29.9% (n = 227) experienced CAN recovery, and 1.2% (n = 9) recovered completely. In a multivariate model, younger age (odds ratio [OR] per 5-year decrease 1.49; 95% confidence interval [CI] 1.25–1.78, P < 0.001), shorter duration of diabetes (OR per 5-year decrease 1.33; 95% CI 1.05–1.67, P = 0.016), presence of micro/macroalbuminuria (OR 0.34; 95% CI 0.15–0.78, P = 0.011), body weight reduction (OR per 1-kg decrease 1.11; 95% CI 1.02–1.21, P = 0.016), and HbA1c reduction (OR per 1% decrease 1.32; 95% CI 1.05–1.67, P = 0.019) were significantly associated with composite events of partial and complete CAN recovery. Age had the highest relative significance among the associated clinical factors. In addition, younger age was the only significant factor in complete CAN recovery.

Conclusions

Younger age was the most important factor in CAN recovery in subjects with type 2 diabetes, including recovery from the definite or severe stage. HbA1c reduction, body weight reduction, no concurrent micro/macroalbuminuria, and shorter duration of diabetes were also significantly associated with CAN recovery.

Electronic supplementary material

The online version of this article (10.1186/s12933-019-0830-4) contains supplementary material, which is available to authorized users.

Exposure to antenatal corticosteroids and reduced respiratory sinus arrhythmia in adult survivors of extremely low birth weight

Purpose/aim: Antenatal corticosteroid (ACS) therapy has dramatically increased survival rates among extremely low birth weight (ELBW) infants. However, the long-term effects of ACS on autonomic nervous system function have not been explored. Using the world's oldest longitudinally followed cohort of ELBW infants we compared respiratory sinus arrhythmia (RSA) among ELBW survivors whose mothers received ACS (ELBW-S), those who did not (ELBW-NS) and normal birth weight (NBW) controls in their 20 and 30 s. Methods: Resting electrocardiogram (ECG) was recorded from ELBW-S (n = 28), ELBW-NS (n = 36), and matched NBW controls (n = 79) at 22-26 and 29-36 years. Resting RSA was compared across groups via analyses of covariance (ANCOVA), adjusting for sex, medication use, postnatal steroid exposure and the presence of chronic health conditions. RSA was also compared across assessments for each group. Results: At 29-36 years, resting RSA in ELBW-S was significantly lower than in NBW controls. RSA in the ELBW-NS group was intermediate between ELBW-S and NBW groups. Although the ELBW-S group also showed nominally reduced RSA compared to NBW controls at the 22-26-year visit, this difference was not statistically significant. Conclusions: ELBW survivors exposed to ACS had lower RSA than NBW controls during their 30 s, suggestive of a decline in parasympathetic input to heart. ELBW survivors who received ACS may be particularly vulnerable to cardiovascular problems in later life.

Sympathetic nervous system as a target for aging and obesity-related cardiovascular diseases

Chronic sympathetic nervous system overactivity is a hallmark of aging and obesity and contributes to the development of cardiovascular diseases including hypertension and heart failure. The cause of this chronic sympathoexcitation in aging and obesity is multifactorial and centrally mediated. In this mini-review, we have provided an overview of the key and emerging central mechanisms contributing to the pathogenesis of sympathoexcitation in obesity and healthy aging, specifically focusing on hypertension. A clear understanding of these mechanisms will pave way for targeting the sympathetic nervous system for the treatment of cardiovascular diseases in obesity and aging.

Ageing, the autonomic nervous system and arrhythmia: From brain to heart

An ageing myocardium possesses significant electrophysiological alterations that predisposes the elderly patient to arrhythmic risk. Whilst these alterations are intrinsic to the cardiac myocytes, they are modulated by the cardiac autonomic nervous system (ANS) and consequently, ageing of the cardiac ANS is fundamental to the development of arrhythmias. A systems-based approach that incorporates the influence of the cardiac ANS could lead to better mechanistic understanding of how arrhythmogenic triggers and substrates interact spatially and temporally to produce sustained arrhythmia and why its incidence increases with age. Despite the existence of physiological oscillations of ANS activity on the heart, pathological oscillations can lead to defective activation and recovery properties of the myocardium. Such changes can be attributable to the decrease in functionality and structural alterations to ANS specific receptors in the myocardium with age. These altered ANS adaptive responses can occur either as a normal ageing process or accelerated in the presence of specific cardiac pathologies, such as genetic mutations or neurodegenerative conditions. Targeted intervention that seek to manipulate the ageing ANS influence on the myocardium may prove to be an efficacious approach for the management of arrhythmia in the ageing population.

Arrhythmia induction using isoproterenol or epinephrine during electrophysiology study for supraventricular tachycardia

BACKGROUND

Electrophysiology study (EPS) is an important part of the diagnosis and workup for supraventricular tachycardia (SVT). Provocative medications are used to induce arrhythmias, when they are not inducible at baseline. The most common medication is the β1-specific agonist, isoproterenol, but recent price increases have resulted in a shift toward the nonspecific agonist, epinephrine.

OBJECTIVE

We hypothesize that isoproterenol is a better induction agent for SVT during EPS than epinephrine.

METHODS

We created a retrospective cohort of 131 patients, who underwent EPS and required medication infusion with either isoproterenol or epinephrine for SVT induction. The primary outcome was arrhythmia induction.

RESULTS

Successful induction was achieved in 71% of isoproterenol cases and 53% of epinephrine cases (P = 0.020). Isoproterenol was significantly better than epinephrine for SVT induction during EPS (odds ratio [OR], 2.35; 95% confidence interval [CI], 1.14-4.85; P = 0.021). There was no difference in baseline variables or complications between the two groups. Other variables associated with successful arrhythmia induction included a longer procedure duration and atrioventricular nodal re-entry tachycardia as the clinical arrhythmia. In a multivariable model, isoproterenol remained significantly associated with successful induction (OR, 2.57; 95% CI, 1.002-6.59; P = 0.05).

CONCLUSIONS

Isoproterenol was significantly better than epinephrine for SVT arrhythmia induction. However, epinephrine was safe and successfully induced arrhythmias in the majority of patients who received it. Furthermore, when atropine was added in epinephrine-refractory cases, in a post hoc analysis there was no difference in arrhythmia induction between medications. Cost savings could thus be significant without compromising safety.

Adolescents' brain-autonomic coupling during emotion processing

Autonomic nervous system (ANS) activity is a core component of emotion processing. The limbic system and medial prefrontal cortex play important roles in the regulation of ANS activity. However, the integration of brain activity and ANS activity has yet to be investigated in adolescents despite independent evidence of adolescents' heightened neural and physiological sensitivity to emotional stimuli. The present study examined the relations of ANS activity in the parasympathetic nervous system (PNS) and sympathetic nervous system (SNS) with brain activity during emotional face processing in adolescents. 135 adolescents (65 female; M = 17.15 yr, SD = 0.42) completed an emotional faces task during an fMRI scan while electrocardiography and skin conductance were recorded simultaneously. Using linear mixed-effect modelling, we tested the effect of change in respiratory sinus arrhythmia (RSA), a measure of PNS activity, and number of skin conductance responses (SCRs), a measure of SNS activity, on neural activity while adolescents viewed emotional faces. Greater RSA withdrawal, indicating decreased PNS activity, was associated with increased activation in the ventromedial prefrontal cortex (vmPFC). More SCRs, indicating greater SNS activity, were associated with decreased activation in several regions including the dorsomedial prefrontal cortex and increased activation in the left hippocampus. Left hippocampus-SCR coupling and vmPFC-RSA coupling predicted baseline SCR and RSA respectively. These findings implicate the hippocampus for potentiating SNS activity, document that regulation of SNS and PNS activity are coordinated with distinct regions of the medial prefrontal cortex, and suggest potential developmental differences in vmPFC regulation of PNS activity between adolescents and adults.