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Recent experimental evidence suggests combined treatment with midazolam and allopregnanolone is more effective than midazolam alone in terminating seizures triggered by acute organophosphate (OP) intoxication. However, there are concerns that combined midazolam and allopregnanolone increases risk of adverse cardiovascular events. To address this, we used telemetry devices to record cardiovascular responses in adult male Sprague-Dawley rats acutely intoxicated with diisopropylfluorophosphate (DFP). Animals were administered DFP (4 mg/kg, sc), followed immediately by atropine (2 mg/kg, i.m.) and 2-PAM (25 mg/kg, i.m.). At 40 min post-exposure, a subset of animals received midazolam (0.65 mg/kg, im); at 50 min, these rats received a second dose of midazolam or allopregnanolone (12 mg/kg, im). DFP significantly increased blood pressure by ~ 80 mmHg and pulse pressure by ~ 34 mmHg that peaked within 12 min. DFP also increased core temperature by ~ 3.5 °C and heart rate by ~ 250 bpm that peaked at ~ 2 h. Heart rate variability (HRV), an index of autonomic function, was reduced by ~ 80%. All acute (within 15 min of exposure) and two-thirds of delayed (hours after exposure) mortalities were associated with non-ventricular cardiac events within 10 min of cardiovascular collapse, suggesting that non-ventricular events should be closely monitored in OP-poisoned patients. Compared to rats that survived DFP intoxication without treatment, midazolam significantly improved recovery of cardiovascular parameters and HRV, an effect enhanced by allopregnanolone. These data demonstrate that midazolam improved recovery of cardiovascular and autonomic function and that the combination of midazolam and allopregnanolone may be a better therapeutic strategy than midazolam alone.

Background: Catheter ablation (CA) is a well-established treatment for atrial fibrillation (AF). However, its effects on autonomic function and underlying mechanisms remain poorly understood. This study investigated autonomic and haemodynamic changes following CA and explored their potential implications for patient outcomes. Methods: Seventy-eight patients with AF underwent CA and were followed up at one, three, and six months. Autonomic function was assessed using a combination of head-up tilt (HUT), handgrip (HG), and deep breathing (DB) manoeuvres along with baroreflex sensitivity (BRS) and baroreflex effectiveness index (BEI) evaluation. Heart rate (HR), blood pressure (BP), and their variability were measured at each time point. Results: Significant autonomic alterations were observed after ablation, particularly at one month, with reductions in parasympathetic tone and baroreflex function. These changes gradually normalised by six months. Both pulmonary vein isolation (PVI) and cryoablation (CryO) had similar effects on autonomic regulation. Improvements in quality of life, measured by the AFEQT scores, were consistent with these physiological changes. Conclusions: CA for AF induces significant time-dependent autonomic and haemodynamic changes with recovery over six months. These findings underscore the need for ongoing monitoring and personalised post-ablation management. Further research is required to explore the mechanisms driving these alterations and their long-term impacts on patient outcomes. [ABSTRACT FROM AUTHOR]

Loss of regulation of the autonomic nervous system is found in many diseases from the age of 50 to 60 yr and even more so in older patients. The imbalance is usually manifested by an increase in sympathetic tone, long considered to be the most deleterious element in terms of cardiac rhythmic risk, but also by a reduction in the effectiveness of short-term regulation of the baroreflex arc (partial loss of parasympathetic control). Techniques for analysing this autonomic disorder by analysing heart rate regulation are widely available in outpatient clinics and provide interesting indicators of cardiovascular and cerebrovascular risk. Deceleration capacity of cardiac autonomic control has been identified for its prognostic role in high-risk patients and in the general population. Further research is indicated to assess the value of this marker in anaesthetic risk management by targeting procedures with greater risk of intraoperative and postoperative autonomic dysfunction. [ABSTRACT FROM AUTHOR]

We aimed to investigate the electrocardiogram (ECG) features in persons with chronic disorders of consciousness (DOC, ≥ 29 days since injury, DSI) resulted from the most severe brain damages. The ECG data from 30 patients with chronic DOC and 18 healthy controls (HCs) were recorded during resting wakefulness state for about five minutes. The patients were classified into vegetative state (VS) and minimally conscious state (MCS). Eight ECG metrics were extracted for comparisons between the subject subgroups, and regression analysis of the metrics were conducted on the DSI (29–593 days). The DOC patients exhibit a significantly higher heart rate (HR, p = 0.009) and lower values for SDNN (p = 0.001), CVRR (p = 0.009), and T-wave amplitude (p < 0.001) compared to the HCs. However, there're no significant differences in QRS, QT, QTc, or ST amplitude between the two groups (p > 0.05). Three ECG metrics of the DOC patients—HR, SDNN, and CVRR—are significantly correlated with the DSI. The ECG abnormalities persist in chronic DOC patients. The abnormalities are mainly manifested in the rhythm features HR, SDNN and CVRR, but not the waveform features such as QRS width, QT, QTc, ST and T-wave amplitudes. The abnormal cardiac rhythmic features (heart rate, HR, and heart rate variability, HRV) are found to persist in long-term (measured after 29 ~ 593 days since injury, DSI) in patients with disorders of consciousness (DOC). HR and HRV are respectively negatively and positively related to DSI. These findings have important implications on DOC patient management. [ABSTRACT FROM AUTHOR]

Objectives: This study investigates the mediating roles of autonomic function and mental health in the association between sleep and cognitive decline in adults aged 50 and above. Method: A total of 2,697 participants with observations on sleep and mediators at baseline and repeated measures of cognitive function (MMSE) were included. Clusters of individuals with similar cognitive trajectories (high-stable, mid-stable and low-declining) were identified. Multinomial logistic regressions were used to estimate the likelihood of membership to each trajectory group based on sleep duration and disturbance. Finally, mediation analysis tested potential mediating effects of autonomic function and mental health underpinning the sleep–cognition relationship. Results: Short (p =.028), long (p =.019), and disturbed sleep (p =.008) increased the likelihood of a low-declining cognitive trajectory. Mental health measures fully attenuated relationships between cognitive decline and short or disturbed sleep but not long sleep. No autonomic function mediation was observed. Conclusion: Older adults with short or disturbed sleep are at risk of cognitive decline due to poor mental health. Individuals with long sleep are also at risk, however, the acting pathways remain to be identified. These outcomes have clinical implications, potentially identifying intervention strategies targeting mental health and sleep as prophylactic measures against dementia. [ABSTRACT FROM AUTHOR]

Abstract Background Late-life depression (LLD) is a prevalent neuropsychiatric disorder in the older population. While LLD exhibits high mortality rates, depressive symptoms in older adults are often masked by physical health conditions. In younger adults, depression is associated with deficits in pupil light reflex and eye blink rate, suggesting the potential use of these responses as biomarkers for LLD. Methods We conducted a study using video-based eye-tracking to investigate pupil and blink responses in LLD patients (n = 25), older (OLD) healthy controls (n = 29), and younger (YOUNG) healthy controls (n = 25). The aim was to determine whether there were alterations in pupil and blink responses in LLD compared to both OLD and YOUNG groups. Results LLD patients displayed significantly higher blink rates and dampened pupil constriction responses compared to OLD and YOUNG controls. While tonic pupil size in YOUNG differed from that of OLD, LLD patients did not exhibit a significant difference compared to OLD and YOUNG controls. GDS-15 scores in older adults correlated with light and darkness reflex response variability and blink rates. PHQ-15 scores showed a correlation with blink rates, while MoCA scores correlated with tonic pupil sizes. Conclusions The findings demonstrate that LLD patients display altered pupil and blink behavior compared to OLD and YOUNG controls. These altered responses correlated differently with the severity of depressive, somatic, and cognitive symptoms, indicating their potential as objective biomarkers for LLD.

Children with obstructive sleep apnea (OSA) frequently experience chronic low-grade systemic inflammation, with the inflammasome playing a central role in OSA. This cross-sectional study evaluated the relationship between weight status, autonomic function, and systemic inflammation in a cohort of 55 children with OSA, predominantly boys (78%) with an average age of 7.4 ± 2.2 years and an apnea-hypopnea index of 14.12 ± 17.05 events/hour. Measurements were taken of body mass index (BMI), sleep heart-rate variability, morning circulatory levels of interleukin-1β, interleukin-1 receptor antagonist, and interleukin-6, and tumor necrosis factor-α, anthropometry, and polysomnography. Multiple linear regression modeling showed that an apnea-hypopnea index was significantly associated with BMI, the standard deviation of successive differences between normal-to-normal intervals during N3 sleep, and the proportion of normal-to-normal interval pairs differing by more than 50 ms during rapid-eye-movement sleep. A moderated mediation model revealed that interleukin-1 receptor antagonist levels mediated the association between BMI and interleukin-6 levels, with sympathovagal balance during N3 sleep and minimum blood oxygen saturation further moderating these relationships. This study highlights the complex relationships between BMI, polysomnographic parameters, sleep heart-rate-variability metrics, and inflammatory markers in children with OSA, underlining the importance of weight management in this context. [ABSTRACT FROM AUTHOR]

(1) Background: The rise in sedentary lifestyles has led to more spinal malformations in the population. These malformations are connected to the body's autonomic function, which can negatively impact long-term health. Heart rate variability can be used as a marker to measure how different postures affect autonomic health. This systematic review aims to explore the link between posture and heart rate variability and evaluate potential interventions to address the consequences of sedentary lifestyles. (2) Methods: Data sources: Studies exploring the relationship between posture and heart rate variability were found using PubMed, Embase, Web of Science, and Cochrane on 1 July 24. Eligibility criteria: People aged 18 years or above with a sedentary lifestyle were included. Studies involving children or participants with spinal/musculoskeletal conditions impacting their ability to walk or sit were excluded as they would not accurately reflect posture analysis. PRISMA guidelines were followed throughout, and the quality assessment was achieved using the QualSyst tool. (3) Results: Out of the 753 papers identified, only five met the eligibility criteria. These studies exhibited heterogeneity regarding interventions, aims, and participant populations. All five studies were prospective case series, enabling analysis and comparisons. (4) Conclusions: According to this study, the seated position, especially the forward truncal flexion, had the most significant impact on heart rate variability and sympathetic tone. It may be inferred that sedentary behavior encourages this stress on the body, which can affect one's health, increasing the mortality rate. [ABSTRACT FROM AUTHOR]

Introduction: This study investigates the effects of yoga, specifically meditation and pranayama, on the autonomic nervous system (ANS) functions. Methods: Thirty healthy volunteers were taken for the study. Heart Rate variability and Ewingbattery of autonomic tests comprises analysis of heart rate variations during deep breathing test (DBT), lying to standing test (LST), standardized Valsalvamanoeuvre (VM), Cold Pressor test (CPT) and sustained handgrip (SHG) were conducted before and after the intervention. Results: Results showed significant changes in systolic blood pressure (SBP), diastolic blood pressure (DBP)and delta values of SBP and DBP in Ewing battery tests. A highly significant decrease in NN50 and pNN50 and a significant increase in Valsalva ratio was also observed. The findings suggest that yoga, particularly meditation and pranayama, can positively influence autonomic functions. Conclusion: The findings suggest that meditation have positive effects on Autonomic Nervous System Balance. [ABSTRACT FROM AUTHOR]

In mid-later life adults, early-onset and late-onset (i.e., onset ≥50 years) depression appear to be underpinned by different pathophysiology yet have not been examined in relation to autonomic function. Sleep provides an opportunity to examine the autonomic nervous system as the physiology changes across the night. Hence, we aimed to explore if autonomic profile is altered in mid-later life adults with remitted early-onset, late-onset and no history of lifetime depression. Participants aged 50–90 years (n = 188) from a specialised clinic underwent a comprehensive clinical assessment and completed an overnight polysomnography study. General Linear Models were used to examine the heart rate variability differences among the three groups for four distinct sleep stages and the wake after sleep onset. All analyses controlled for potential confounders – age, sex, current depressive symptoms and antidepressant usage. For the wake after sleep onset, mid-later life adults with remitted early-onset depression had reduced standard deviation of Normal to Normal intervals (SDNN; p =.014, d = −0.64) and Shannon Entropy (p =.004, d = −0.46,) than those with no history of lifetime depression. Further, the late-onset group showed a reduction in high-frequency heart rate variability (HF n.u.) during non-rapid eye movement sleep stage 2 (N2; p =.005, d = −0.53) and non-rapid eye movement sleep stage 3 (N3; p =.009, d = −0.55) when compared to those with no lifetime history. Causality between heart rate variability and depression cannot be derived in this cross-sectional study. Longitudinal studies are needed to examine the effects remitted depressive episodes on autonomic function. The findings suggest differential autonomic profile for remitted early-onset and late-onset mid-later life adults during sleep stages and wake periods. The differences could potentially serve as peripheral biomarkers in conjunction with more disease-specific markers of depression to improve diagnosis and prognosis. • Autonomic dysfunction is a key risk factor and symptom of major depressive disorder. • No known studies have examined the relationship between HRV and history of depression. • History of depression is associated with the integrity of autonomic functioning in mid-later life adults. • HRV has the potential to be a biomarker of depression. [ABSTRACT FROM AUTHOR]

Introduction: Concussion is known to cause transient autonomic and cerebrovascular dysregulation that generally recovers; however, few studies have focused on individuals with an extensive concussion history. Method: The case was a 26-year-old male with a history of 10 concussions, diagnosed for bipolar type II disorder, mild attention-deficit hyperactivity disorder, and a history of migraines/headaches. The case was medicated with Valproic Acid and Escitalopram. Sensor-based baseline data were collected within six months of his injury and on days 1–5, 10, and 14 post-injury. Symptom reporting, heart rate variability (HRV), neurovascular coupling (NVC), and dynamic cerebral autoregulation (dCA) assessments were completed using numerous biomedical devices (i.e., transcranial Doppler ultrasound, 3-lead electrocardiography, finger photoplethysmography). Results: Total symptom and symptom severity scores were higher for the first-week post-injury, with physical and emotional symptoms being the most impacted. The NVC response showed lowered activation in the first three days post-injury, while autonomic (HRV) and autoregulation (dCA) were impaired across all testing visits occurring in the first 14 days following his concussion. Conclusions: Despite symptom resolution, the case demonstrated ongoing autonomic and autoregulatory dysfunction. Larger samples examining individuals with an extensive history of concussion are warranted to understand the chronic physiological changes that occur following cumulative concussions through biosensing devices. [ABSTRACT FROM AUTHOR]

Background: Treatment options for abdominal pain in IBS are inadequate. TEA was reported effective treatment of disorders of gut–brain interaction but its mechanism of action and optimal delivery method for treating pain in IBS are unknown. This study aims to determine the most effective TEA parameter and location to treat abdominal pain in patients with IBS‐Constipation and delineate the effect of TEA on rectal sensation and autonomic function. Methods: Nineteen IBS‐C patients underwent TEA at acupoints ST36 (leg), PC6 (wrist), or sham‐acupoint. Each patient was studied in five randomized sessions on separate days: (1) TEA/ST36‐100 Hz; (2) TEA/ST36‐25 Hz; (3) TEA/PC6‐100 Hz; (4) TEA/PC6‐25 Hz; (5) TEA/Sham‐25 Hz. In each session, barostat‐guided rectal distention (RD) was performed before and after TEA. Patients graded the RD‐induced pain and recorded three rectal sensation thresholds. A heart rate variability (HRV) signal was derived from the electrocardiogram for autonomic function assessment. Key Results: Studied patients were predominantly female, young, and Caucasian. Compared with baseline, patients treated with TEA/ST36‐100 Hz had significantly decreased pain scores at RD pressure‐points 20–50 mmHg (p < 0.04). The average pain reduction was 40%. Post‐treatment scores did not change significantly with other TEA modalities except with sham‐TEA (lesser degree compared to ST36‐100 Hz, p = 0.04). TEA/ST36‐100, but not other modalities, increased the rectal sensation threshold (first sensation: p = 0.007; urge to defecate: p < 0.026). TEA/ST36‐100 Hz was the only treatment that significantly decreased sympathetic activity and increased parasympathetic activity with and without RD (p < 0.04). Conclusions & Inferences: TEA at ST36‐100 Hz is superior stimulation point/parameter, compared to TEA at PC‐6/sham‐TEA, to reduce rectal distension‐induced pain in IBS‐C patients. This therapeutic effect appears to be mediated through rectal hypersensitivity reduction and autonomic function modulation. [ABSTRACT FROM AUTHOR]

Health care workers were exposed to huge stress during COVID-19 pandemic affecting their physical and mental health. Practice of anulom vilom pranayama and heartfulness meditation (AVPHFN) can improve mental and physical health and counter stress. The present study explored the effect of 8-week AVPHFN intervention on autonomic functions, emotional stress, oxidative stress, and inflammation markers in the nurse group of health-care givers. This was a randomized controlled trial where 50 nurses underwent AVPHFN and 50 participated as controls. At baseline and after 8 week intervention of AVPHFN anthropometric parameters, cardiovascular parameters, autonomic function including time and frequency domain parameters, biochemical parameters, and psychological stress using the questionnaire were assessed. Forty nurses in AVPHFN group and 46 in control group completed the study. AVPHFN intervention resulted in a significant reduction in cardiovascular parameters heart rate, systolic blood pressure, diastolic blood pressure, mean arterial pressure and rate pressure product (p<0.001, p<0.001, p<0.001, p<0.001, and p<0.001, respectively), perceived stress score and depression, anxiety, and stress scale psychological variables of depression, and stress compared to the control group. Total power, ratio of low frequency to high frequency and change in successive normal sinus (NN) intervals exceeds 50 ms (p<0.01, p=0.05, and p<0.01 respectively) suggesting parasympathodominance due to higher vagal efferent activity. Serum cortisol, high-sensitivity C-reactive protein (hs-CRP), tumor necrosis factor-alpha, interleukin (IL)-1, IL-6 and telomerase significantly decreased in AVPHFN group post intervention. Eighty-week intervention of AVPHFN improved psychophysiological, autonomic and biochemistry profile of nurse group of health-care workers. AVPHFN module may be beneficial for curtailing stress and improving well-being. [ABSTRACT FROM AUTHOR]

Background: Late-life depression (LLD) is a prevalent neuropsychiatric disorder in the older population. While LLD exhibits high mortality rates, depressive symptoms in older adults are often masked by physical health conditions. In younger adults, depression is associated with deficits in pupil light reflex and eye blink rate, suggesting the potential use of these responses as biomarkers for LLD. Methods: We conducted a study using video-based eye-tracking to investigate pupil and blink responses in LLD patients (n = 25), older (OLD) healthy controls (n = 29), and younger (YOUNG) healthy controls (n = 25). The aim was to determine whether there were alterations in pupil and blink responses in LLD compared to both OLD and YOUNG groups. Results: LLD patients displayed significantly higher blink rates and dampened pupil constriction responses compared to OLD and YOUNG controls. While tonic pupil size in YOUNG differed from that of OLD, LLD patients did not exhibit a significant difference compared to OLD and YOUNG controls. GDS-15 scores in older adults correlated with light and darkness reflex response variability and blink rates. PHQ-15 scores showed a correlation with blink rates, while MoCA scores correlated with tonic pupil sizes. Conclusions: The findings demonstrate that LLD patients display altered pupil and blink behavior compared to OLD and YOUNG controls. These altered responses correlated differently with the severity of depressive, somatic, and cognitive symptoms, indicating their potential as objective biomarkers for LLD. [ABSTRACT FROM AUTHOR]

Spinal cord injury leads to disruption in autonomic control resulting in cardiovascular, bowel, and lower urinary tract dysfunctions, all of which significantly reduce health-related quality of life. Although spinal cord stimulation shows promise for promoting autonomic recovery, the underlying mechanisms are unclear. Based on current preclinical and clinical evidence, this narrative review provides the most plausible mechanisms underlying the effects of spinal cord stimulation for autonomic recovery, including activation of the somatoautonomic reflex and induction of neuroplastic changes in the spinal cord. Areas where evidence is limited are highlighted in an effort to guide the scientific community to further explore these mechanisms and advance the clinical translation of spinal cord stimulation for autonomic recovery. [ABSTRACT FROM AUTHOR]

Background and objectives: Dysautonomia has been associated with paraneoplastic neurological syndrome (PNS)-related mortality in anti-Hu PNS, but its frequency and spectrum remain ill-defined. We describe anti-Hu patients with dysautonomia, estimate its frequency, and compare them to patients without dysautonomia. Methods: Patients with anti-Hu antibodies diagnosed in the study centre (1990–2022) were retrospectively reviewed; those with autonomic signs and symptoms were identified. Results: Among 477 anti-Hu patients, 126 (26%) had dysautonomia (the only PNS manifestation in 7/126, 6%); gastrointestinal (82/126, 65%), cardiovascular (64/126, 51%), urogenital (24/126, 19%), pupillomotor/secretomotor (each, 11/126, 9%), and central hypoventilation (10/126, 8%). Patients with isolated CNS involvement less frequently had gastrointestinal dysautonomia than those with peripheral (alone or combined with CNS) involvement (7/23, 30% vs. 31/44, 70% vs. 37/52, 71%; P = 0.002); while more frequently central hypoventilation (7/23, 30% vs. 1/44, 2.3% vs. 2/52, 4%; P < 0.001) and/or cardiovascular alterations (18/23, 78% vs. 20/44, 45% vs. 26/52, 50%; P = 0.055). Median [95% CI] overall survival was not significantly different between patients with (37 [17; 91] months) or without dysautonomia (28 [22; 39] months; P = 0.78). Cardiovascular dysautonomia (HR: 1.57, 95% CI [1.05; 2.36]; P = 0.030) and central hypoventilation (HR: 3.51, 95% CI [1.54; 8.01]; P = 0.003) were associated with a higher risk of death, and secretomotor dysautonomia a lower risk (HR: 0.28, 95% CI [0.09; 0.89]; P = 0.032). Patients with cardiovascular dysautonomia dying ≤ 1 year from clinical onset had severe CNS (21/27, 78%), frequently brainstem (13/27, 48%), involvement. Discussion: Anti-Hu PNS dysautonomia is rarely isolated, frequently gastrointestinal, cardiovascular and urogenital. CNS dysfunction, particularly brainstem, associates with lethal cardiovascular alterations and central hypoventilation, while peripheral involvement preferentially associates with gastrointestinal or secretomotor dysautonomia, being the latest more indolent. [ABSTRACT FROM AUTHOR]

Context: Autonomic dysfunction (AD) brings up cardiovascular morbidity/mortality and has been reported in chronic kidney disease (CKD). Still, the pattern of AD in CKD is elusive. Aim: To evaluate the distribution of cardiovascular dysautonomia in CKD. Material and Methods: This study was conducted on 33 CKD cases and 30 age and sex matched healthy controls. Five standard autonomic function tests were conducted, namely, heart rate response to Valsalva maneuver, deep breathing, and standing, and BP response to standing and sustained handgrip; based on which the patients were classified as normal, or having early parasympathetic, definite parasympathetic and combined damage. The total autonomic function score was also calculated. Results: All cases belonged to CKD stages of 3, 4, and 5; and came up with autonomic failure. The mean total autonomic function score was higher (P < 0.001) in CKD (5.09 ± 2.33) as compared to the control group (0.97 ± 0.24), using the unpaired “t” test. Most of the CKD patients (45.45%) were involved with combined damage. Of the three stages, combined damage struck stage 5 to the maximum extent (63.63%). Sympathetic failure always co occurred with parasympathetic failure. Conclusion: Combined autonomic failure is more conspicuous in late CKD, predominantly occurring in stage 5. The disease course may contort the parasympathetic system before the sympathetic system.

Background: Individuals with posttraumatic stress disorder (PTSD) are at heightened risk for cardiovascular disease (CVD) compared to the general population. Inflammation and autonomic dysfunction are candidate mechanisms of CVD risk in PTSD; however, these mechanisms have not been well-characterised in the PTSD-CVD link. Further, these mechanisms may operate through altered stress-related neural activity (SNA). Yet, it remains unknown if changes in PTSD are associated with changes in CVD risk mechanisms.Objective: This manuscript describes the design and procedures of a pilot randomised controlled trial to assess the impact of a first-line treatment for PTSD (Cognitive Processing Therapy; CPT) versus waitlist control on mechanisms of CVD risk. Further, this study will test the hypothesis that CPT reduces CVD risk through its effects on inflammation and autonomic function and that these changes are driven by changes in SNA.Methods: Adults with PTSD and CVD risk (N = 30) will be randomised to CPT or waitlist control. Participants complete two laboratory visits (baseline and post-treatment) that include surveys, brain and peripheral imaging via 18F-fluorodeoxyglucose positron emission tomography (FDG-PET), and resting measures of autonomic function. Primary outcomes include arterial inflammation and heart rate variability. Secondary outcomes include leukopoiesis (bone marrow uptake), heart rate, and blood pressure. The indirect effects of PTSD treatment on changes in inflammation and autonomic function through SNA will also be examined.Conclusions: This study seeks to characterise candidate neuroimmune mechanisms of the PTSD-CVD link to identify treatment targets and develop personalised interventions to reduce CVD events in PTSD populations.Trial registration: ClinicalTrials.gov identifier: NCT06429293..

Background: Secondhand smoke (SHS) is a significant risk factor for cardiovascular morbidity and mortality with an estimated 80% of SHS-related deaths attributed to cardiovascular causes. Public health measures and smoking bans have been successful both in reducing SHS exposure and improving cardiovascular outcomes in non-smokers. Soluble epoxide hydrolase (sEH) inhibitors have been shown to attenuate tobacco exposure-induced lung inflammatory responses, making them a promising target for mitigating SHS exposure-induced cardiovascular outcomes. Objectives: The objectives of this study were to determine 1) effects of environmentally relevant SHS exposure on cardiac autonomic function and blood pressure (BP) regulation and 2) whether prophylactic administration of an sEH inhibitor (TPPU) can reduce the adverse cardiovascular effects of SHS exposure. Methods: Male C57BL/6J mice (11 weeks old) implanted with BP/electrocardiogram (ECG) telemetry devices were exposed to filtered air or 3 mg/m3 of SHS (6 hr/d, 5 d/wk) for 12 weeks, followed by 4 weeks of recovery in filtered air. Some mice received TPPU in drinking water (15 mg/L) throughout SHS exposure. BP, heart rate (HR), HR variability (HRV), baroreflex sensitivity (BRS), and BP variability were determined monthly. Results: SHS exposure significantly decreased 1) short-term HRV by ∼20% (p < 0.05) within 4 weeks; 2) overall HRV with maximum effect at 12 weeks (-15%, p < 0.05); 3) pulse pressure (-8%, p < 0.05) as early as week 4; and 4) BRS with maximum effect at 12 weeks (-11%, p < 0.05). Four weeks of recovery following 12 weeks of SHS ameliorated all SHS-induced cardiovascular detriments. Importantly, mice exposed to TPPU in drinking water during SHS-related exposure were protected from SHS cardiovascular consequences. Discussion: The data suggest that 1) environmental relevant SHS exposure significantly alters cardiac autonomic function and BP regulation; 2) cardiovascular consequences from SHS can be reversed by discontinuing SHS exposure; and 3) inhibiting sEH can prevent SHS-induced cardiovascular consequences.

Objective: To investigate the circadian changes of the autonomic function in patients with zoster‐associated pain (ZAP). Methods: A total of 37 patients with ZAP from April 2022 to October 2022 were enrolled as the observation group, and 37 normal volunteers at the same time were selected as the control group. All participants were required to wear a 24‐h Holter, which was used to compare the heart rate variability (HRV) between the two groups. HRV analysis involved time‐ and frequency‐domain parameters. Results: There was no statistically significant difference in general information between two groups. Patients with ZAP had an increased mean heart rate and decreased the standard deviation of normal‐to‐normal (SDNN) R–R interval, the root mean square of the differences (RMSSD) in successive RR interval, low frequency (LF), and high frequency (HF) compared with control groups in all periods (p <.05). The ratio of LF/HF between two groups had no significant difference (p =.245). SDNN had no significant difference between day and night in the control group (p >.05), whereas SDNN of ZAP patients in night period was reduced than that in day period (p <.001). The level of RMSSD during the day was lower than those at night in the control group (p <.05), whereas no significant difference of RMSSD between two periods was observed in patients with ZAP (p >.05). Conclusion: The results of this study indicated that ZAP contributes to the decline of autonomic nervous system (ANS) function, especially parasympathetic components. The patients with ZAP lost parasympathetic advantage and had a worse ANS during the night. In this work, we conducted an observational study of Circadian Changes of Autonomic Function in Patients with Zoster‐associated Pain via HRV. To our best knowledge, our study is one of the rare and comprehensive attempts to explore circadian changes of autonomic function in patients with ZAP via 24‐hour heart rate variability analysis. The results of this study indicated that ZAP contributes to change in the ANS resulting in decreased the function of ANS and PNS in all periods. The patients with ZAP lost parasympathetic advantage and had a worse ANS during the night. [ABSTRACT FROM AUTHOR]

Background and aim: Laryngopharyngeal reflux disease (LPRD) is primarily characterized by discomfort in the pharynx and has limited treatment options. This research aimed to assess the efficacy of transcutaneous auricular vagus nerve stimulation (tVNS) in patients with LPRD and delve into the potential underlying mechanisms. Methods: A total of 44 participants, diagnosed with LPRD were divided into two groups randomly. Twice-daily stimulation was delivered for 2 weeks for patients in experimental group, with stimulation ranging from 1.0  mA to 1.5  mA (n  =  22), while the control group underwent sham tVNS (n  =  22) with the same stimulation parameters and different anatomical location. The severity of symptoms and levels of anxiety and depression were monitored using questionnaires. Highresolution esophageal manometry data were collected, and the patients’ autonomic function was assessed through heart rate variability analysis. Results: There was a positive correlation between reflux symptom index (RSI) scores and low frequency/high frequency (LF/HF) ratio (r  =  0.619; p  <  0.001), Hamilton anxiety scale (HAMA) scores (r  =  0.623; p  <  0.001), and Hamilton depression scale (HAMD) scores (r  =  0.593; p  <  0.001). Compared to the pretVNS phase, RSI (p  <  0.001), HAMA (p  <  0.001), and HAMD (p  <  0.001) scores were significantly reduced after 2 weeks of treatment. Additionally, the resting pressure of the upper esophageal sphincter (UESP; p  <  0.05) and lower esophageal sphincter (LESP; p  <  0.05) showed significant enhancement. Notably, tVNS led to an increase in root mean square of successive differences (RMSSD; p  <  0.05) and high frequency (HF; p  <  0.05) within heart rate variability compared to the pre-treatment baseline. Compared to the control group, RSI (p  <  0.001), HAMA (p  <  0.001), and HAMD (p  <  0.001) scores in tVNS group were significantly lower at the end of treatment. Similarly, the resting pressure of UESP (p  <  0.05) and LESP (p  <  0.05) in tVNS group were significantly higher than that of control group. Notably, RMSSD (p  <  0.05) and HF (p  <  0.05) in tVNS group were significantly higher than that of control group. Conclusion: This study demonstrated that tVNS as a therapeutic approach is effective in alleviating LPRD symptoms. Furthermore, it suggests that improvements in esophageal motility could be associated with vagus nervedependent mechanisms. [ABSTRACT FROM AUTHOR]

Functional somatic syndromes (FSSs) represent a clinically important group of disorders that are often stress-related. Their autonomic pathophysiology, including reduced heart rate variability (HRV), has been reported. However, the response pattern to mental stress and recovery in FSSs remains unclear. Thus, we aimed to clarify the pattern of autonomic stress response and recovery to mental arithmetic stress in patients with FSS compared to that in healthy controls. This cross-sectional study included 79 patients with FSS who visited the Department of Psychosomatic Medicine at a university hospital in Japan and 39 healthy controls. Following a mood questionnaire and obtaining epidemiologic information, HRV was measured during three periods (5 min each): relaxation baseline resting, stress (mental arithmetic task), and post-stress recovery period. The HRV analysis included inter-beat interval, low frequency power, and high frequency power. Compared to healthy controls, patients with FSS exhibited significantly higher scores on the mood questionnaire, prolonged duration of illness, and decreased functionality in daily activities. While the healthy control group showed a pronounced stress response pattern with a significant decrease in vagal HRV and recovery, the FSS group showed a "flat" vagal stress response pattern, and the HRV in the FSS group was lower at relaxation baseline, remained low during the stress, and did not change post stress. Patients with severe FSS exhibit an altered stress response pattern. Our results could provide significant clues for the diagnosis and treatment of such patients, as well as useful insights into the relationship between stress and illness. [ABSTRACT FROM AUTHOR]

to characterize possible differences in the function of the ANS in patients with chronic insomnia compared to a control group, using a wearable device, in order to determine whether those findings allow diagnosing this medical entity. Thirty-two patients with chronic insomnia and nineteen patients without any sleep disorder, as a control group, were recruited prospectively. Both groups of patients underwent an in-patient night with simultaneous polysomnography and wearable device recording Empatica E4 a diverse array of physiological signals, including electrodermal activity, temperature, accelerometry, and photoplethysmography, providing a comprehensive resource for in-depth sleep analysis. In polysomnography, patients suffering from insomnia showed a significant decrease in sleep efficiency and total sleep time, prolonged sleep latency, and increased wakefulness after sleep onset. Accelerometry results were statistically significant differences in the three axis (x, y, z) just in stage N3, no differences were observed between both groups in REM sleep. The lowest temperature was reached in REM sleep in both groups. Peripheral temperature did not decrease during the different sleep phases compared to wakefulness in insomnia, unlike in the control group. Heart rate was higher in patients with insomnia than in controls during wakefulness and sleep stage. Heart rate variability was lower in stage N3 and higher in REM sleep compared to wakefulness in both groups. Sweating was significantly higher in patients with insomnia compared to the control group, as indicated by Skin Conductance Variability values and Sudomotor Nerve. Our study suggests that patients with insomnia have increased sympathetic activity during sleep, showing a higher heart rate. Temperature and sweating significantly influence the different sleep phases. • The association between insomnia and cardiovascular events has raised a growing interest in sleep disorders in recent decades. • Accelerometry allowed identifying superficial sleep, SWS and REM sleep in both groups. Wearable devices have been considered a useful tool in the clinical practice of sleep medicine centers. • Patients with insomnia have increased sympathetic activity during sleep as they showed higher heart rate and heart rate variability during all stages of sleep. The association between chronic insomnia and hyper-activation may have consequences, increasing the risk of developing cardiovascular diseases. • Skin temperature variations related to the NREM and REM sleep cycles were minimal in the insomnia and control groups. Both groups showed the lowest temperature during REM sleep. • Sweating, were significantly influenced by the different sleep phases. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to evaluate the effect of mandibular advancement splint (MAS) therapy on cardiac autonomic function in patients with obstructive sleep apnoea (OSA) using heart rate variability (HRV) analysis. Methods: Electrocardiograms (ECG) derived from polysomnograms (PSG) of three prospective studies were used to study HRV of patients with OSA before and after MAS treatment. HRV parameters were averaged across the entire ECG signal during N2 sleep using 2-min epochs shifted by 30 s. Paired t-tests were used to compare PSG and HRV measures before and after treatment, and the percent change in HRV measures was regressed on the percent change in apnoea-hypopnea index (AHI). Results: In 101 patients with OSA, 72% were Caucasian, 54% men, the mean age was 56 ± 11 years, BMI 29.8 ± 5.3 kg/m2, and treatment duration was 4.0 ± 3.2 months. After MAS therapy, there was a significant reduction in OSA severity (AHI, − 18 ± 16 events per hour, p < 0.001) and trends towards increased low-frequency to high-frequency ratio, low-frequency power, and reduced high-frequency power (LF:HF, − 0.4 ± 1.5, p = 0.01; LF, − 3 ± 16 nu, p = 0.02, HF, 3.5 ± 13.7 nu, p = 0.01). Change in NN intervals correlated with the change in AHI (β(SE) = − 2.21 (0.01), t = − 2.85, p = 0.005). No significant changes were observed in the time-domain HRV markers with MAS treatment. Conclusion: The study findings suggest that successful MAS treatment correlates with changes in HRV, specifically the lengthening of NN intervals, a marker for improved cardiac autonomic adaptability. [ABSTRACT FROM AUTHOR]

Background: Heart rate variability (HRV) is an indicator of autonomic abnormalities. However, little is known about the role of HRV related to substance use behavior and the association between the changes in HRV and signs of relapse in substance use. Aim: The purpose of this study was to review the existing literature on autonomic response to substance use (i.e., opioids, cocaine, and methamphetamine) measured by HRV and its outcomes related to the risk factors of relapse. Methods: A systematic search of the literature was conducted using PubMed, PsychINFO, and Ovid Medline databases. The study includes full-text articles published in English from 2010 to 2020, using measures of HRV in human subjects who use substances. Results: A total of 14 studies were reviewed. Studies included outpatients with a prescription or nonprescription opioid misuse behavior with a primary diagnosis being chronic pain or substance use disorder (SUD). Significantly decreased resting HRV was found in substance users compared to healthy controls. Lower resting HRV has been significantly associated with stress, craving, and greater symptom severities in individuals with SUD and other substance dependence. HRV indices can be potential measures of homeostatic imbalance and self-regulation flexibility. Conclusion: HRV may be a useful tool for monitoring early indication of relapse so that relapse prevention measures can be implemented in a timely manner. Future studies in substance use may benefit from examining HRV in relations to substance use and relapse signs and symptoms in a larger population to guide future relapse prevention strategies. [ABSTRACT FROM AUTHOR]

Abstract Data on the impact of arterial stiffness on autonomic function are limited. We sought to investigate whether heart rate recovery (HRR), a predictor of autonomic function, is impaired in patients with increased arterial stiffness. A total of 475 participants (mean age 55.8 ± 11.1 years, 34.3% women) who underwent a treadmill exercise test (TET) for the evaluation of chest pain were retrospectively analyzed. All patients underwent brachial-ankle pulse wave velocity (baPWV) measurement on the same day. HRR was defined as the difference in heart rate from maximal exercise to 1 min of recovery. Participants with the lowest HRR tertile were older and had more cardiovascular risk factors than those with the highest HRR tertile. Simple correlation analysis showed that baPWV was negatively correlated with HRR (r = − 0.327, P

Abstract Background Postural tachycardia syndrome (POTS), a subset of orthostatic dysregulation, has been reported to be associated with anxiety. POTS can be classified into two forms based on the degree of tachycardia during orthostasis. Reportedly, POTS with decreased orthostatic heart rate increase is associated with suppressed cardiac parasympathetic activity and increased sympathetic activity in the supine position. In this study, the relationship between the two types of POTS and anxiety was evaluated in terms of autonomic function. Methods Fifty-two patients (23 male, age 10–15 years) who were diagnosed with POTS at the Department of Pediatrics, Osaka Medical and Pharmaceutical University from 2019 to 2021, completed a standing test and were accordingly classified into a Su group, with tachycardia from the supine position and a low heart rate increase on standing, a SI group, with a high heart rate increase during standing. They then completed the State-Trait Anxiety Scale for Children (STAIC) questionnaire. Autonomic function was assessed by frequency analysis (MemCalc method) based on heart rate, blood pressure changes, heart rate and blood pressure variability during the orthostatic test. Results Patients in the Su group had higher trait anxiety and state anxiety, lower cardiac parasympathetic activity (RR-HF) in the supine position, and greater variability in cardiac parasympathetic activity during orthostasis than were found for patients in the SI group. The Su group had a greater decrease in cardiac index on standing than that of the SI group. Conclusions The Su group results may be partly attributed to chronically low venous return. We also found that patients in the Su group had low parasympathetic activity in the supine position, which may interact with the anxiety-prone characteristics of these patients. Therefore, it seems necessary to consider both physical and psychosomatic treatment approaches for patients with POTS.

PURPOSE: Resting heart rate variability (HRV) is an important biomarker linking mental health to cardiovascular outcomes. However, resting HRV is also impaired in autonomic neuropathy, a common and underdiagnosed complication of common medical conditions which is detected by testing autonomic reflexes. We sought to describe the relationship between autonomic reflex abnormalities and resting HRV, taking into consideration medical comorbidities and demographic variables. METHODS: Participants (n = 209) underwent a standardized autonomic reflex screen which was summarized as the Composite Autonomic Severity Score (CASS) and included measures of reflexive HRV, e.g., heart rate with deep breathing (HRDB). Resting HRV measures were: pNN50 (percentage of NN intervals that differ by > 50 ms) and cvRMSSD (adjusted root mean square of successive differences). RESULTS: In univariate analyses, lower resting HRV was associated with: older age, higher CASS, neuropathy on examination, hypertension, diabetes, chronic obstructive pulmonary disease, chronic kidney disease, and psychiatric disease. Adaptive regression spline analysis revealed that HRDB explained 27% of the variability in resting HRV for participants with values of HRDB in the normal range. Outside this range, there was no linear relationship because: (1) when HRDB was low (indicating autonomic neuropathy), resting HRV was also low with low variance; and (2) when HRDB was high, the variance in resting HRV was high. In multivariate models, only HRDB was significantly independently associated with cvRMSSD and pNN50. CONCLUSION: Subclinical autonomic neuropathy, as evidenced by low HRDB and other autonomic reflexes, should be considered as a potential confounder of resting HRV in research involving medically and demographically diverse populations.

(1) Background: Spinal cord injury (SCI) represents a major health challenge, often leading to significant and permanent sensorimotor and autonomic dysfunctions. This study reviews the evolving role of epidural spinal cord stimulation (eSCS) in treating chronic SCI, focusing on its efficacy and safety. The objective was to analyze how eSCS contributes to the recovery of neurological functions in SCI patients. (2) Methods: We utilized the PRISMA guidelines and performed a comprehensive search across MEDLINE/PubMed, Embase, Web of Science, and IEEE Xplore databases up until September 2023. We identified studies relevant to eSCS in SCI and extracted assessments of locomotor, cardiovascular, pulmonary, and genitourinary functions. (3) Results: A total of 64 studies encompassing 306 patients were identified. Studies investigated various stimulation devices, parameters, and rehabilitation methods. Results indicated significant improvements in motor function: 44% of patients achieved assisted or independent stepping or standing; 87% showed enhanced muscle activity; 65% experienced faster walking speeds; and 80% improved in overground walking. Additionally, eSCS led to better autonomic function, evidenced by improvements in bladder and sexual functions, airway pressures, and bowel movements. Notable adverse effects included device migration, infections, and post-implant autonomic dysreflexia, although these were infrequent. (4) Conclusion: Epidural spinal cord stimulation is emerging as an effective and generally safe treatment for chronic SCI, particularly when combined with intensive physical rehabilitation. Future research on standardized stimulation parameters and well-defined therapy regimens will optimize benefits for specific patient populations. [ABSTRACT FROM AUTHOR]

Metabolic syndrome (MetS) describes a set of disorders that collectively influence cardiovascular health, and includes hypertension, obesity, insulin resistance, diabetes, and dyslipidemia. All these components (hypertension, obesity, dyslipidemia, and prediabetes/diabetes) have been shown to modify autonomic function. The major autonomic dysfunction that has been documented with each of these components is in the control of sympathetic outflow to the heart and periphery at rest and during exercise through modulation of the arterial baroreflex and the muscle metaboreflex. Many studies have described MetS components in singularity or in combination with the other major components of metabolic syndrome. However, many studies lack the capability to study all the factors of metabolic syndrome in one model or have not focused on studying the effects of how each component as it arises influences overall autonomic function. The goal of this review is to describe the current understanding of major aspects of metabolic syndrome that most likely contribute to the consequent/associated autonomic alterations during exercise and discuss their effects, as well as bring light to alternative mechanisms of study. [ABSTRACT FROM AUTHOR]

Background: Postural tachycardia syndrome (POTS), a subset of orthostatic dysregulation, has been reported to be associated with anxiety. POTS can be classified into two forms based on the degree of tachycardia during orthostasis. Reportedly, POTS with decreased orthostatic heart rate increase is associated with suppressed cardiac parasympathetic activity and increased sympathetic activity in the supine position. In this study, the relationship between the two types of POTS and anxiety was evaluated in terms of autonomic function. Methods: Fifty-two patients (23 male, age 10–15 years) who were diagnosed with POTS at the Department of Pediatrics, Osaka Medical and Pharmaceutical University from 2019 to 2021, completed a standing test and were accordingly classified into a Su group, with tachycardia from the supine position and a low heart rate increase on standing, a SI group, with a high heart rate increase during standing. They then completed the State-Trait Anxiety Scale for Children (STAIC) questionnaire. Autonomic function was assessed by frequency analysis (MemCalc method) based on heart rate, blood pressure changes, heart rate and blood pressure variability during the orthostatic test. Results: Patients in the Su group had higher trait anxiety and state anxiety, lower cardiac parasympathetic activity (RR-HF) in the supine position, and greater variability in cardiac parasympathetic activity during orthostasis than were found for patients in the SI group. The Su group had a greater decrease in cardiac index on standing than that of the SI group. Conclusions: The Su group results may be partly attributed to chronically low venous return. We also found that patients in the Su group had low parasympathetic activity in the supine position, which may interact with the anxiety-prone characteristics of these patients. Therefore, it seems necessary to consider both physical and psychosomatic treatment approaches for patients with POTS. [ABSTRACT FROM AUTHOR]

Attention deficit/hyperactivity disorder (ADHD) is a heterogeneous neuro developmental condition, that continues to have an elusive etiological background. A number of extant models and theories have historically intended to explain the many factors contributing to ADHD behaviors. One of the most accepted hypotheses has been the executive dysfunction theory associating reduction in executive control to abnormalities in structure and operational dysfunction of dopaminergic signaling networks. Nevertheless, executive functions are not always impaired in ADHD, and the literature describes other symptoms commonly reported suggesting individuals with ADHD would appear to suffer from a more general deficit. Another existing line of research, that has gained much attention recently, establishes that ADHD would have dysregulated states of brain arousal that would account for its commonly observed cognitive deficits and behavioral symptoms, described as the state regulation theory, which has now included measures of autonomic function. This article describes some important aspects that compose and challenge these two most influential theoretical constructs, executive dysfunction and state-regulation, based on their empirical evidence, implying the need to reevaluate the norms used to classify individuals and establish ADHD diagnosis. Large number of controversial results continue to exist within the study of ADHD biological and/ or performance markers, possibly due to such heterogeneity and variability within the same diagnosis. The need to resolve these issues and establish newly revised diagnostic criteria for ADHD is critical, as therapeutic success depends on having accurately identified underlying neurophysiological factors in order to appropriately address them in treatment. [ABSTRACT FROM AUTHOR]

Great part of Chagas disease (ChD) mortality occurs due to ventricular arrhythmias, and autonomic function (AF) may predict unfavorable outcomes. We aimed to evaluate the predictive value of AF indexes in ChD patients. The Bambuí Study of Aging is a prospective cohort of residents ≥60 years at study onset (1997), in the southeastern Brazilian city of Bambuí (15,000 inhabitants). Consented participants underwent annual follow-up visits, and death certificates were tracked. AF was assessed by the maximum expiration on minimum inspiration (E:I) ratio during ECG acquisition and by heart rate variability indices: SDRR (standard deviation of adjacent RR intervals) and RMSSD (square root of the mean of the sum of squares of the differences between adjacent RR intervals)), calculated using a computer algorithm. Cox proportional hazards regression was performed to access the prognostic value of AF indexes, expressed as terciles, for all-cause mortality, after adjustment for demographic, clinical and ECG variables. From 1742 qualifying residents, 1000 had valid AF tests, being 321 with ChD. Among these, median age was 68 (64–74) years, and 32.5% were men. In Cox survival analyses, only SDRR was associated with all-cause mortality in non-adjusted models: SDRR (hazard ratio (HR): 1.26 (95% CI 1.08–1.47), p < 0.001), E:I ratio (HR: 1.13 (95% CI 0,98–1.31), p = 0.10) and RMSSD (HR: 0.99 (0.86–1.16), p = 0.95). After adjustment for sex and age, none of the indexes remained as independent predictors. Among elderly patients with ChD, AF indexes available in this cohort were not independent predictors of 14-year mortality. [ABSTRACT FROM AUTHOR]

Females typically exhibit lower blood pressure (BP) during exercise than males. However, recent findings indicate that adjusting for maximal strength attenuates sex differences in BP during isometric handgrip (HG) exercise and postexercise ischemia (PEI; metaboreflex isolation). In addition, body size is associated with HG strength but its contribution to sex differences in exercising BP is less appreciated. Therefore, the purpose of this study was to determine whether adjusting for strength and body size would attenuate sex differences in BP during HG and PEI. We obtained beat-to-beat BP in 110 participants (36 females, 74 males) who completed 2 min of isometric HG exercise at 40% of their maximal voluntary contraction followed by 3 min of PEI. In a subset (11 females, 17 males), we collected muscle sympathetic nerve activity (MSNA). Statistical analyses included independent t tests and mixed models (sex x time) with covariate adjustment for 40% HG force, height2, and body surface area. Females exhibited a lower absolute 40% HG force than male participants (Ps < 0.001). Females exhibited lower Dsystolic, Ddiastolic, and Dmean BPs during HG and PEI than males (e.g., PEI, Dsystolic BP, 15 ± 11 vs. 23 ± 14 mmHg; P = 0.004). After covariate adjustment, sex differences in BP responses were attenuated. There were no sex differences in MSNA. In a smaller strength-matched cohort, there was no sex x time interactions for BP responses (e.g., PEI systolic BP, P = 0.539; diastolic BP, P = 0.758). Our data indicate that sex differences in exercising BP responses are attenuated after adjusting for muscle strength and body size. [ABSTRACT FROM AUTHOR]

Background: Hypertension can be classified into different phenotypes based on systolic and diastolic blood pressure (BP) that carry a different prognosis and may therefore be differently associated with sympathetic activity. We assessed the association between cardiac autonomic function determined from continuous finger BP recordings and hypertensive phenotypes. Methods: We included 10,221 individuals aged between 18-70 years from the multi-ethnic HELIUS study. Finger BP was recorded continuously for 3-5 minutes from which cross-correlation baroreflex sensitivity (xBRS) and heart rate variability (HRV) were determined. Hypertension was classified into isolated systolic (ISH; ≥140/<90), diastolic (IDH; <140/≥90) and combined systolic and diastolic hypertension (SDH; ≥140/≥90). Differences were assessed after stratification by age (younger: ≤40, older: >40 years) and sex, using regression with correction for relevant covariates. For xBRS, values were log-transformed. Results: In younger adults with ISH, xBRS was comparable to normotensive individuals in men (ratio 0.92; 95%CI 0.84-1.01) and women (1.00; 95%CI 0.84-1.20), while xBRS was significantly lower in IDH and SDH (ratios between 0.67 and 0.80). In older adults, all hypertensive phenotypes had significantly lower xBRS compared to normotensives. We found a similar pattern for HRV in men, while in women HRV did not differ between phenotypes. Conclusions: In younger men and women ISH is not associated with a shift towards increased sympathetic control, while IDH and SDH in younger and all hypertensive phenotypes in older participants were associated with increased sympathetic control. This suggests that alterations in autonomic regulation could be a contributing factor to known prognostic disparities between hypertensive phenotypes. Hypertension can be classified into different phenotypes based on systolic and diastolic blood pressure (BP) that carry a different prognosis. Impaired autonomic regulation is important in the pathogenesis of hypertension and independently associated with adverse cardiovascular outcomes. We analyzed 3-5 minutes continuous non-invasive finger blood pressure recordings performed in over 10.000 individuals participating in the HELIUS cohort study. From these measurements, short term heart rate variability (HRV) and cross correlation baroreflex sensitivity (xBRS) were determined using an automatic algorithm. In our analysis we observed pronounced differences in the relation between autonomic regulation and hypertensive phenotypes that depend on age and sex. Younger men and women (age 18-40 years) with isolated systolic hypertension had similar values for xBRS and HRV compared to normotensives, while isolated diastolic hypertension was associated with a shift towards increased sympathetic control. In contrast to our findings in younger individuals, all hypertensive phenotypes were associated with increased sympathetic control in older participants (age 40-70 years). This supports earlier studies showing prognostic differences and suggests that alterations in sympathovagal balance could be a contributing factor to the disparities between phenotypes. [ABSTRACT FROM AUTHOR]

Internet addiction is characterized by excessive or poorly controlled preoccupations, urges or behaviors regarding computer use and internet access that lead to impairment or distress. The present study was conducted to evaluate the efficacy of internet de-addiction programme on stress and autonomic functions in young adults. 500 young adults (age group 18-35 years), using smartphones and other gadget frequently were asked to answer Kimberley Young's Internet addiction test (IAT) questionnaire. As per their responses 31 moderates to severely addicted to internet addiction (IAT score 64.51 ± 16.94) were motivated to participate in a comprehensive internet de-addiction programme, based on repeated sessions of psychological counselling and behavioral therapy as advised by an expert clinical Psychologist. Baseline and follow up (after 6 weeks) recording of Heart rate, Blood pressure, Perceived stress scale, IAT, Autonomic functions based on frequency domain HRV were done. There was significant increase in total power of HRV whereas significant reduction in LF/HF ratio, Perceived stress scores (PSS), Internet addiction scores and average daily mobile usage time after 6 weeks of follow up. It can be concluded from this study that after six weeks of comprehensive sessions based on cognitive behaviour therapy and guiding for self-help approach there were significant decrease in the total daily mobile usages time, internet addiction score, perceived stress score and also simultaneous improvement in symptho-vagal tone and overall autonomic health of participants. [ABSTRACT FROM AUTHOR]

• Patients with lower extremity arterial disease present with cardiac autonomic dysfunction. • Walking training enhances cardiac parasympathetic modulations in this population. • We recommended the use of a checklist for future trials assessing heart rate variability. To perform a systematic review of studies assessing the effects of regular exercise on heart rate variability (HRV) in individuals with lower extremity arterial disease (LEAD) and symptoms of claudication. A systematic search in the electronic databases MEDLINE, Embase, and Scielo, was conducted and updated on January 21, 2023. Randomized clinical trials investigating patients with LEAD and IC, assessing ≥ 4 wk of exercise interventions, and reporting at least one HRV measure (e.g., time or frequency domains) at baseline and follow-up were included. Two reviewers independently screened studies for inclusion, performed data extraction, and quality assessment of included studies. Data from 7 trials were included (i.e., 5 walking, 1 resistance, and 1 isometric handgrip training), totaling 327 patients (66% males; range: 61 - 68 yr; ankle brachial index: 0.4 - 0.7). Following exercise training, three studies investigating walking training reported an increase in parasympathetic modulation indices and/or a decrease in sympathetic modulation indices (n = 2) as well as an increase in non-linear indices (n = 1). The current evidence is weak, and larger randomized controlled trials are needed to confirm the efficacy of exercise training in improving HRV. Additionally, the high divergence in the methodology of studies indicated the need for standard tools to improve the quality of HRV measurements in exercise trials. It is recommended to use standard procedures in future trials investigating HRV. [ABSTRACT FROM AUTHOR]

Slow heart rate recovery following exercise may be influenced by persistent sympathoexcitation. This study examined 1) the effect of muscle metaboreflex activation (MMA) on heart rate recovery following dynamic exercise; and 2) whether the effect of MMA on heart rate recovery is reversible by reducing sympathoexcitation [baroreflex activation via phenylephrine (PE)] in canines. Twenty-two young adults completed control and MMA protocols during cycle ergometry at 110% ventilatory threshold with 5 min recovery. Heart rate recovery kinetics [tau (s), amplitude, end-exercise, and end-recovery heart rate] and root mean square of successive differences (RMSSD) were measured. Five chronically instrumented canines completed control, MMA (50%-60% imposed reduction in hindlimb blood flow), and MMA with end-exercise PE infusion (MMA þ PE) protocols during moderate exercise (6.4 km·h-1) and 3 min recovery. Heart rate recovery kinetics and MAP were measured. MAP increased during MMA versus control in canines (P < 0.001). Heart rate recovery s was slower during MMA versus control in humans (17% slower; P = 0.011) and canines (150% slower; P = 0.002). Heart rate recovery s was faster during MMA þ PE versus MMA (40% faster; P = 0.034) and was similar to control in canines (P = 0.426). Amplitude, end-exercise, and end-recovery heart rate were similar between conditions in humans (all P = 0.122) and in canines (all P ≥ 0.084). MMA decreased RMSSD in early recovery (P = 0.004). MMAinduced sympathoexcitation slows heart rate recovery and this effect is markedly attenuated with PE. Therefore, elevated sympathoexcitation via MMA impairs heart rate recovery and inhibition of this stimulus normalizes, in part, heart rate recovery. [ABSTRACT FROM AUTHOR]

Abstract Objective To investigate the circadian changes of the autonomic function in patients with zoster‐associated pain (ZAP). Methods A total of 37 patients with ZAP from April 2022 to October 2022 were enrolled as the observation group, and 37 normal volunteers at the same time were selected as the control group. All participants were required to wear a 24‐h Holter, which was used to compare the heart rate variability (HRV) between the two groups. HRV analysis involved time‐ and frequency‐domain parameters. Results There was no statistically significant difference in general information between two groups. Patients with ZAP had an increased mean heart rate and decreased the standard deviation of normal‐to‐normal (SDNN) R–R interval, the root mean square of the differences (RMSSD) in successive RR interval, low frequency (LF), and high frequency (HF) compared with control groups in all periods (p .05), whereas SDNN of ZAP patients in night period was reduced than that in day period (p .05). Conclusion The results of this study indicated that ZAP contributes to the decline of autonomic nervous system (ANS) function, especially parasympathetic components. The patients with ZAP lost parasympathetic advantage and had a worse ANS during the night.

Background Insulin is a peptide hormone that regulates post-prandial physiology, and it is well known that insulin controls homeostasis at least in part via the central nervous system. In particular, insulin alters the activity of neurons within the autonomic nervous system. However, currently available data are mostly from unidentified brainstem neurons of the dorsal motor nucleus of the vagus nerve (DMV). Methods In this study, we used several genetically engineered mouse models to label distinct populations of neurons within the brainstem and the spinal cord for whole-cell patch clamp recordings and to assess several in vivo metabolic functions. Results We first confirmed that insulin directly inhibited cholinergic (parasympathetic preganglionic) neurons in the DMV. We also found inhibitory effects of insulin on both the excitatory and inhibitory postsynaptic currents recorded in DMV cholinergic neurons. In addition, GABAergic neurons of the DMV and nucleus tractus solitarius were inhibited by insulin. However, insulin had no effects on the cholinergic sympathetic preganglionic neurons of the spinal cord. Finally, we obtained results suggesting that the insulin-induced inhibition of parasympathetic preganglionic neurons may not play a critical role in the regulation of glucose homeostasis and gastrointestinal motility. Conclusion Our results demonstrate that insulin inhibits parasympathetic neuronal circuitry in the brainstem, while not affecting sympathetic neuronal activity in the spinal cord.

(1) Background: The rise in sedentary lifestyles has led to more spinal malformations in the population. These malformations are connected to the body’s autonomic function, which can negatively impact long-term health. Heart rate variability can be used as a marker to measure how different postures affect autonomic health. This systematic review aims to explore the link between posture and heart rate variability and evaluate potential interventions to address the consequences of sedentary lifestyles. (2) Methods: Data sources: Studies exploring the relationship between posture and heart rate variability were found using PubMed, Embase, Web of Science, and Cochrane on 1 July 24. Eligibility criteria: People aged 18 years or above with a sedentary lifestyle were included. Studies involving children or participants with spinal/musculoskeletal conditions impacting their ability to walk or sit were excluded as they would not accurately reflect posture analysis. PRISMA guidelines were followed throughout, and the quality assessment was achieved using the QualSyst tool. (3) Results: Out of the 753 papers identified, only five met the eligibility criteria. These studies exhibited heterogeneity regarding interventions, aims, and participant populations. All five studies were prospective case series, enabling analysis and comparisons. (4) Conclusions: According to this study, the seated position, especially the forward truncal flexion, had the most significant impact on heart rate variability and sympathetic tone. It may be inferred that sedentary behavior encourages this stress on the body, which can affect one’s health, increasing the mortality rate.

Children with obstructive sleep apnea (OSA) frequently experience chronic low-grade systemic inflammation, with the inflammasome playing a central role in OSA. This cross-sectional study evaluated the relationship between weight status, autonomic function, and systemic inflammation in a cohort of 55 children with OSA, predominantly boys (78%) with an average age of 7.4 ± 2.2 years and an apnea-hypopnea index of 14.12 ± 17.05 events/hour. Measurements were taken of body mass index (BMI), sleep heart-rate variability, morning circulatory levels of interleukin-1β, interleukin-1 receptor antagonist, and interleukin-6, and tumor necrosis factor-α, anthropometry, and polysomnography. Multiple linear regression modeling showed that an apnea-hypopnea index was significantly associated with BMI, the standard deviation of successive differences between normal-to-normal intervals during N3 sleep, and the proportion of normal-to-normal interval pairs differing by more than 50 ms during rapid-eye-movement sleep. A moderated mediation model revealed that interleukin-1 receptor antagonist levels mediated the association between BMI and interleukin-6 levels, with sympathovagal balance during N3 sleep and minimum blood oxygen saturation further moderating these relationships. This study highlights the complex relationships between BMI, polysomnographic parameters, sleep heart-rate-variability metrics, and inflammatory markers in children with OSA, underlining the importance of weight management in this context.

Introduction: Concussion is known to cause transient autonomic and cerebrovascular dysregulation that generally recovers; however, few studies have focused on individuals with an extensive concussion history. Method: The case was a 26-year-old male with a history of 10 concussions, diagnosed for bipolar type II disorder, mild attention-deficit hyperactivity disorder, and a history of migraines/headaches. The case was medicated with Valproic Acid and Escitalopram. Sensor-based baseline data were collected within six months of his injury and on days 1–5, 10, and 14 post-injury. Symptom reporting, heart rate variability (HRV), neurovascular coupling (NVC), and dynamic cerebral autoregulation (dCA) assessments were completed using numerous biomedical devices (i.e., transcranial Doppler ultrasound, 3-lead electrocardiography, finger photoplethysmography). Results: Total symptom and symptom severity scores were higher for the first-week post-injury, with physical and emotional symptoms being the most impacted. The NVC response showed lowered activation in the first three days post-injury, while autonomic (HRV) and autoregulation (dCA) were impaired across all testing visits occurring in the first 14 days following his concussion. Conclusions: Despite symptom resolution, the case demonstrated ongoing autonomic and autoregulatory dysfunction. Larger samples examining individuals with an extensive history of concussion are warranted to understand the chronic physiological changes that occur following cumulative concussions through biosensing devices.

Attention deficit/hyperactivity disorder (ADHD) is a heterogeneous neurodevelopmental condition, that continues to have an elusive etiological background. A number of extant models and theories have historically intended to explain the many factors contributing to ADHD behaviors. One of the most accepted hypotheses has been the executive dysfunction theory associating reduction in executive control to abnormalities in structure and operational dysfunction of dopaminergic signaling networks. Nevertheless, executive functions are not always impaired in ADHD, and the literature describes other symptoms commonly reported suggesting individuals with ADHD would appear to suffer from a more general deficit. Another existing line of research, that has gained much attention recently, establishes that ADHD would have dysregulated states of brain arousal that would account for its commonly observed cognitive deficits and behavioral symptoms, described as the state regulation theory, which has now included measures of autonomic function. This article describes some important aspects that compose and challenge these two most influential theoretical constructs, executive dysfunction and state-regulation, based on their empirical evidence, implying the need to reevaluate the norms used to classify individuals and establish ADHD diagnosis. Large number of controversial results continue to exist within the study of ADHD biological and/or performance markers, possibly due to such heterogeneity and variability within the same diagnosis. The need to resolve these issues and establish newly revised diagnostic criteria for ADHD is critical, as therapeutic success depends on having accurately identified underlying neurophysiological factors in order to appropriately address them in treatment.

Background: Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) carries variability in arterial flow pulsatility (AFP). Research question: What changes in cerebral and somatic oxygenation, hemodynamics, and autonomic function are associated with AFP during VA-ECMO? Methods: This is a prospective study of children on VA-ECMO undergoing neuromonitoring. AFP was quantified by arterial blood pressure pulse amplitude and subcategorized: no pulsatility (

Background: Hypertension can be classified into different phenotypes based on systolic and diastolic blood pressure (BP) that carry a different prognosis and may therefore be differently associated with sympathetic activity. We assessed the association between cardiac autonomic function determined from continuous finger BP recordings and hypertensive phenotypes. Methods: We included 10,221 individuals aged between 18-70 years from the multi-ethnic HELIUS study. Finger BP was recorded continuously for 3-5 minutes from which cross-correlation baroreflex sensitivity (xBRS) and heart rate variability (HRV) were determined. Hypertension was classified into isolated systolic (ISH; ≥140/40 years) and sex, using regression with correction for relevant covariates. For xBRS, values were log-transformed. Results: In younger adults with ISH, xBRS was comparable to normotensive individuals in men (ratio 0.92; 95%CI 0.84-1.01) and women (1.00; 95%CI 0.84-1.20), while xBRS was significantly lower in IDH and SDH (ratios between 0.67 and 0.80). In older adults, all hypertensive phenotypes had significantly lower xBRS compared to normotensives. We found a similar pattern for HRV in men, while in women HRV did not differ between phenotypes. Conclusions: In younger men and women ISH is not associated with a shift towards increased sympathetic control, while IDH and SDH in younger and all hypertensive phenotypes in older participants were associated with increased sympathetic control. This suggests that alterations in autonomic regulation could be a contributing factor to known prognostic disparities between hypertensive phenotypes.

Aims Offspring exposed to an adverse fetal environment, such as gestational diabetes, may manifest increased susceptibility to several chronic diseases later in life. In the present study, the cardiovascular function of three different ages of offspring from diabetic rats was evaluated. Methods and results Diabetes mellitus was induced in pregnant rats by a single dose of streptozotocin (50 mg/kg). The offspring from diabetic (OD) and control rats (OC) were evaluated at three different ages: 6, 12 or 18 months. In the corresponding OC groups, fasting glycemia, baseline mean arterial pressure, and sympathetic tonus increased in the OD rats at 12 (OD12) and 18 (OD18) months of age, while cardiac hypertrophy was observed in all OD groups. Cardiac function evaluation in vivo showed low left ventricular systolic pressure and+dP/dt in the OD18 rats, suggesting a systolic dysfunction. OD12 and OD18 groups showed high left ventricle end-diastolic pressure, suggesting a diastolic dysfunction. OD groups showed an age-related impairment of both baroreflex-mediated tachycardia and baroreflex-mediated bradycardia in OD12 and OD18 rats. In isolated hearts from OD18 rats, both inotropic and tachycardiac responses to increasing isoproterenol were significantly reduced compared to the corresponding OC group. Conclusion These results suggest that gestational diabetes triggers the onset of hyperglycemia hypertension with impaired baroreflex sensitivity and heart failure in older age of offspring, representing important risk factors for death. Therefore, ensuring optimal glycemic control in diabetic pregnancy is important and serves as a key to preventing cardiovascular disease in the offspring in their older age. [ABSTRACT FROM AUTHOR]

Objectives: Heart rate variability (HRV) is a measure of cardiac autonomic function. This study: (1) evaluated the differences in HRV and haemodynamic function between individuals with hypertrophic cardiomyopathy (HCM) and healthy controls, and (2) determined the relationship between HRV and haemodynamic variables in individuals with HCM. Methods: Twenty‐eight individuals with HCM (n = 7, females; age 54 ± 15 years; body mass index: 29 ± 5 kg/m2) and 28 matched healthy individuals (n = 7 females; age 54 ± 16 years; body mass index: 29 ± 5 kg/m2) completed 5‐min HRV and haemodynamic measurements under resting (supine) conditions using bioimpedance technology. Frequency domain HRV measures (absolute and normalized low‐frequency power (LF), high‐frequency power (HF) and LF/HF ratio) and RR interval were recorded. Results: Individuals with HCM demonstrated higher vagal activity (i.e., absolute unit of HF power (7.40 ± 2.50 vs. 6.03 ± 1.35 ms2, p = 0.01) but lower RR interval (914 ± 178 vs. 1014 ± 168 ms, p = 0.03) compared to controls. Stroke volume (SV) index and cardiac index were lower in HCM compared with healthy individuals (SV, 33 ± 9 vs. 43 ± 7 ml‎/beat‎/m², p < 0.01; cardiac index,2.33 ± 0.42 vs. 3.57 ± 0.82 L/min/m2, p < 0.01), but total peripheral resistance (TPR) was higher in HCM (3468 ± 1027 vs. 2953 ± 1050 dyn·s·m2cm−5, p = 0.03). HF power was significantly related to SV (r = −0.46, p < 0.01) and TPR (r = 0.28, p < 0.05) in HCM. Conclusions: Short‐term frequency domain indices of HRV provide a feasible approach to assess autonomic function in individuals with HCM. Vagal activity, represented by HF power, is increased, and associated with peripheral resistance in individuals with HCM. [ABSTRACT FROM AUTHOR]