Effects of Probiotics on Inflammatory Biomarkers and Its Associations With Cardiac Autonomic Function in Women With Arterial Hypertension: A Secondary Analysis of a Randomized Clinical Trial.

Preclinical evidence suggests that probiotic administration may exert an anti-inflammatory effect and reduce autonomic dysfunction and blood pressure. This study evaluated the effects of probiotic therapy on inflammatory biomarkers and characterized the correlations between inflammation and cardiac autonomic function in women with arterial hypertension. Women were randomized into probiotics (n = 20) or placebo (n = 20). The probiotic group received 109 CFU/day of Lactobacillus (L.) paracasei LPC-37, L. rhamnosus HN001, L. acidophilus NCFM, and Bifidobacterium lactis HN019, and the placebo group received polydextrose. Clinical, electrocardiogram, heart rate variability (HRV) analysis, and cytokine levels were assessed at baseline and after 8 weeks. Women who received probiotics for 8 weeks had increased serum levels of IL-17A (p = 0.02) and decreased INF-γ (p = 0.02) compared to baseline. Probiotic supplementation increased serum levels of IL-10 compared to the placebo group (p = 0.03). Probiotic or placebo administration did not change serum levels of TNFα and IL-6. Serum levels of IL-2 (p = 0.001, and p = 0.001) and IL-4 (p = 0.001, and p = 0.001) were reduced in women receiving placebo or probiotics, respectively. Correlations between HRV indices and inflammatory variables showed that INF-γ was positively correlated with heart rate (HR) and sympathetic HRV indices and negatively correlated with vagal HRV indices. IL-10 was negatively correlated with HR and sympathetic HRV indices. IL-6 was negatively correlated with parasympathetic HRV indices and positively correlated with SD2/SD1 ratio. Probiotic therapy has a discreet anti-inflammatory effect in hypertensive women, and pro-inflammatory cytokines were negatively correlated with vagal modulation and positively correlated with sympathetic modulation of HRV. The clinical trial was registered in the Brazilian Registry of Clinical Trials (ReBEC) with the identification RBR-9mj2dt.

Vagal dysautonomia in patients with Chagas disease and mortality: 14-year results of a population cohort of the elderly.

INTRODUCTION: 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. METHODS: 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. RESULTS: 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. CONCLUSION: Among elderly patients with ChD, AF indexes available in this cohort were not independent predictors of 14-year mortality.

The Relationship between Paresthesia and the Presence of Cardiac Dysautonomia in Patients with Post-COVID-19 Syndrome: A Preliminary Observational Study.

INTRODUCTION: Post-Coronavirus disease 2019 (Post-COVID-19) syndrome has neurological symptoms related to the dysfunction of the autonomous nerve system. However, a pathogenic relationship between post-COVID-19 syndrome and dysautonomia still remains to be demonstrated. Establishing a pathogenic relationship between paresthesia and the presence of cardiac dysautonomia in patients with post-COVID-19 syndrome is the objective of this study. PARTICIPANTS AND METHODS: This observational study was carried out in the neurophysiology service wing of the Juan Bruno Zayas Hospital, Santiago de Cuba, in Cuba. The patients were recruited through a post-COVID-19 clinic at the same hospital. A variability study of cardiac frequency and a test of autonomic cardiovascular reflexes was carried out, which is composed of deep breathing, orthostatism, and the Valsalva maneuver. RESULTS: The variability parameters of the cardiac frequency, the expiration-inspiration ratio between deep breaths, and the Valsalva Index showed no statistically significant differences between healthy participants and those with post-COVID-19 syndrome. During the Valsalva maneuver, there was a greater cardiac frequency response in participants with post-COVID-19 syndrome than in healthy subjects. The difference in supine and standing blood pressure was significantly minor in patients with post-COVID-19 syndrome. The logarithm of high frequency (log HF) increased significantly in patients with paresthesia when compared to patients without paresthesia. CONCLUSIONS: In the autonomic function tests, no signs of dysautonomia were found in patients with post-COVID-19 syndrome. The presence of paresthesias is associated with differences in cardiac vagal activity, which may suggest that damage to peripheral sensory nerve fibers could be associated with an affectation to autonomic fibres.

Effects of Preoperative Sarcopenia-Related Parameters on Cardiac Autonomic Function in Women with Obesity Following Bariatric Surgery: A One-Year Prospective Study.

OBJECTIVES: Investigate changes in blood pressure (BP) and heart rate variability (HRV) in women with and without sarcopenia-related parameters who underwent bariatric surgery (BS) during a one-year follow-up. SUBJECTS AND METHODS: Women were separated into obesity (OB, n = 20) and women with obesity displaying sarcopenia-related parameters (SOP, n = 14) and evaluated before BS and 3, 6, and 12 months after BS. SOP was defined as low handgrip strength (HS) and/or low appendicular skeletal mass adjusted for weight (ASM/wt × 100, %) in the lowest quartile of the sample. ASM/wt × 100, % and HS were significantly lower in SOP than OB over a one-year follow-up of BS (p < 0.05). RESULTS: There was a reduction in diastolic BP, heart rate (HR), SDHR, LF, and the LF/HF ratio (p < 0.05) and an increase in the HF band in both groups during the follow-up period (p < 0.05). SOP women had reduced root mean square differences of successive RR intervals (RMSSD) and HF band and an increased LF band and SD2/SD1 ratio compared to the OB group during the one-year follow-up (p < 0.05). ASM/wt × 100, % was negatively associated with the LF band (r = -0.24, p = 0.00) and positively associated with the HF band (r = 0.22, p = 0.01). Conversely, HS had no association with LF (r = -0.14, p = 0.09) and HF (r = 0.11, p = 0.19). ASM/wt × 100, % and HS were negatively associated with the LF/HF ratio (p < 0.05). CONCLUSIONS: Women who underwent BS had an improved HRV over a one-year follow-up. However, the improvement in HRV variables was less pronounced in women with low muscle mass and/or HS during the follow-up period.

Impact of asthma on heart rate variability in children and adolescents: Systematic review and meta-analysis.

PURPOSE: Asthma is associated with abnormal autonomic function, and heart rate variability is considered a simple, accurate, and noninvasive tool for monitoring the autonomic system. Thus, the aim of this study was to investigate the impact of asthma on heart rate variability in children and adolescents. METHODS: This systematic review of observational studies and clinical trials evaluated heart rate variability in children and adolescents with asthma compared to healthy controls. The data were extracted independently by two reviewers. The quality of the selected articles was assessed using Agency for Health Care Research and Quality indicators. Random effects meta-analysis was performed for each outcome, with the effect size reported as standardized mean difference. RESULTS: Fifteen studies were included, of which five were classified as having high methodological quality. In the meta-analysis, long-term recording of the standard deviation of all normal-to-normal sinus R-R intervals differed significantly between groups (standardized mean difference [SMD] = -0.46 [95% confidence interval {CI}: -0.79 to -0.14], p < 0.005, I2 = 0%). Moreover, R-R intervals (long-term) were significantly shorter in asthmatic children than controls (SMD = -0.47 [95% CI: -0.68 to -0.25], p < 0.0001, I2 = 0). There were no significant differences between adjacent normal R-R intervals that exceed 50 ms (long-term) and the root mean square of successive differences between normal sinus R-R intervals (short-term). Regarding frequency-domain variables, long-term low frequency measurements differed significantly between groups (SMD = -0.34 [95% CI: -0.58 to -0.10], p < 0.005, I2 = 15%). There were no differences in high frequency measurements or in the ratio between low/high frequency powers (short- or long-term) between groups. CONCLUSION: The results confirm the impact of asthma on heart rate variability in children and adolescents, indicating lower heart rate variability and sympathetic modulation.

Arousal dysregulation and executive dysfunction in attention deficit hyperactivity disorder (ADHD).

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.

Effects of light-emitting diode therapy on cardiovascular and salivary nitrite responses in postmenopausal women submitted to a single bout of high-intensity interval training.

The aim of the present study was to analyze the effects of light-emitting diode therapy (LEDT) on cardiovascular effort during a single bout of high-intensity interval training (HIIT) and on blood pressure (BP), salivary nitrite, and heart rate variability (HRV) responses after the exercise session in postmenopausal women. Sixteen postmenopausal women between 50 and 70 years of age participated in the present study. The intervention comprised two sessions: placebo plus HIIT and LEDT plus HIIT, with a 14-day interval between sessions. The oxygen uptake (VO2), heart rate (HR), and rating of perceived exertion (RPE) were monitored throughout the HIIT sessions. Salivary samples were taken before, immediately post, and 30' and 60' post-HIIT sessions for nitric oxide (NO) analysis. In addition, HR and BP were checked before, 15 min, 30 min, 45 min, and 60 min post-HIIT sessions. HR data were used to calculate the HRV indices. Cardiovascular parameters during HIIT and BP, HRV, and NO responses were not different between placebo and LEDT conditions (p > 0.05). BP responses increased after compared to pre-exercise (p < 0.01). HRV was impaired post- compared to pre-exercise (p < 0.05). LEDT did not improve physiological performance during HIIT and did not accelerate the recovery of BP and autonomic modulation or change the NO release after exercise in postmenopausal women.

Uterine activity modifies the response of the fetal autonomic nervous system at preterm active labor.

Background: The autonomic nervous system of preterm fetuses has a different level of maturity than term fetuses. Thus, their autonomic response to transient hypoxemia caused by uterine contractions in labor may differ. This study aims to compare the behavior of the fetal autonomic response to uterine contractions between preterm and term active labor using a novel time-frequency analysis of fetal heart rate variability (FHRV). Methods: We performed a case-control study using fetal R-R and uterine activity time series obtained by abdominal electrical recordings from 18 women in active preterm labor (32-36 weeks of gestation) and 19 in active term labor (39-40 weeks of gestation). We analyzed 20 minutes of the fetal R-R time series by applying a Continuous Wavelet Transform (CWT) to obtain frequency (HF, 0.2-1 Hz; LF, 0.05-0.2 Hz) and time-frequency (Flux0, Flux90, and Flux45) domain features. Time domain FHRV features (SDNN, RMSSD, meanNN) were also calculated. In addition, ultra-short FHRV analysis was performed by segmenting the fetal R-R time series according to episodes of the uterine contraction and quiescent periods. Results: No significant differences between preterm and term labor were found for FHRV features when calculated over 20 minutes. However, we found significant differences when segmenting between uterine contraction and quiescent periods. In the preterm group, the LF, Flux0, and Flux45 were higher during the average contraction episode compared with the average quiescent period (p<0.01), while in term fetuses, vagally mediated FHRV features (HF and RMSSD) were higher during the average contraction episode (p<0.05). The meanNN was lower during the strongest contraction in preterm fetuses compared to their consecutive quiescent period (p=0.008). Conclusion: The average autonomic response to contractions in preterm fetuses shows sympathetic predominance, while term fetuses respond through parasympathetic activity. Comparison between groups during the strongest contraction showed a diminished fetal autonomic response in the preterm group. Thus, separating contraction and quiescent periods during labor allows for identifying differences in the autonomic nervous system cardiac regulation between preterm and term fetuses.

Cardiac autonomic function in Chagas disease: a narrative review / Função autonômica cardíaca na doença de Chagas: uma revisão narrativa / Función autonómica cardíaca en la enfermedad de Chagas: una revisión narrativa

Chagas disease (CD) is a severe health problem in countries of Latin America, including Brazil, and is characterised as an acute and chronic infection. CD can affect several organs and cellular tissues, in particular the heart, which can lead to sudden death. This work aimed to review the literature regarding cardiac autonomic function assessed by Heart Rate Variability (HRV) in CD in adult individuals. The search was carried out using the electronic databases PubMed, SciELO, and Web of Science between January 2013 and October 2020. A total of 19 articles were found, of which 14 were included in this review. HRV was demonstrated at baseline conditions, physical exercise, and cardiac rehabilitation. Quantifying CD progression assessed by HRV is an effective method to detect changes in the cardiac autonomic nervous system, even in asymptomatic individuals. Physical exercise can improve autonomic function in CD. Further clinical studies are needed to assess the anatomical-functional, metabolic, and immunological parameters associated with CD evaluated by HRV.

A doença de Chagas (DC) é um grave problema de saúde em países da América Latina, incluindo o Brasil, sendo caracterizada como infecção aguda e crônica. A DC pode afetar vários órgãos e tecidos celulares, em particular o coração, podendo levar à morte súbita. O objetivo deste trabalho foi revisar a literatura relacionada à função autonômica cardíaca avaliada pela Variabilidade da Frequência Cardíaca (VFC) na DC em indivíduos adultos. A busca foi realizada nas bases de dados eletrônicas PubMed, SciELO e Web of Science entre o período de janeiro de 2013 a outubro de 2020. Foram encontrados 19 artigos, dos quais 14 foram incluídos nesta revisão. A VFC foi demonstrada em condições basais, exercícios físicos e reabilitação cardíaca. Quantificar a progressão da DC avaliada pela VFC é um método eficaz para detectar alterações no sistema nervoso autônomo cardíaco, mesmo em indivíduos assintomáticos. O exercício físico pode melhorar a função autonômica na DC. Mais estudos clínicos são necessários para avaliar os parâmetros anátomo-funcionais, metabólicos e imunológicos associados à DC e avaliados pela VFC.

La enfermedad de Chagas (EC) es un grave problema de salud que enfrenta los países de América Latina y se caracteriza por ser una infección aguda y crónica. La EC puede afectar varios órganos y tejidos celulares, en particular el corazón, y puede provocar la muerte súbita. El objetivo de este estudio fue revisar la literatura que relaciona la función autónoma cardíaca evaluada por la Variabilidad de la Frecuencia Cardíaca (VFC) en la EC en individuos adultos. La búsqueda se realizó en las bases de datos electrónicas PubMed, SciELO y Web of Science desde enero de 2013 hasta octubre de 2020. Se encontraron 19 artículos, de los cuales 14 fueron incluidos en esta revisión. La VFC se ha demostrado en condiciones basales, ejercicio físico y rehabilitación cardíaca. La cuantificación de la progresión de la EC evaluada por la VFC es un método eficaz para detectar cambios en el sistema nervioso autónomo cardíaco, incluso en individuos asintomáticos. El ejercicio físico puede mejorar la función autónoma en la EC. Se necesitan más estudios clínicos para evaluar los parámetros anatómico-funcionales, metabólicos e inmunológicos asociados con la EC y evaluados por la VFC.

Linear and non-linear analysis of heart rate variability in HIV-positive patients on two different antiretroviral therapy regimens.

BACKGROUND: Cardiac autonomic dysfunction in HIV+ patients on different antiretroviral therapy (ART) regimens has been described. We aimed to characterize parameters of heart rate variability (HRV) and correlate with different classes of ART in HIV+ patients in three experimental conditions: rest, cold face, and tilt tests. METHODS: Cross-sectional study with three groups of age- and gender-matched individuals: group 1, 44 HIV+ patients undergoing combination therapy, with two nucleoside reverse transcriptase inhibitors (NRTI) and one non-nucleoside reverse transcriptase inhibitor (NNRTI); group 2, 42 HIV+ patients using two NRTI and protease inhibitors (PI's); and group 3, 35 healthy volunteers with negative HIV serology (control group). Autonomic function at rest and during cold face- and tilt-tests was assessed through computerized analysis of HRV, via quantification of time- and frequency domains by linear and non-linear parameters in the three groups. RESULTS: Anthropometric and clinical parameters were similar between both HIV groups, except CD4+ T lymphocytes, which were significantly lower in group 2 (p = 0.039). At baseline, time-domain linear HRV parameters, RMSSD and pNN50, and the correlation dimension, a non-linear HRV parameter (p < 0.001; p = 0.018; p = 0.019, respectively), as well as response of RMSSD to cold face test were also lower in the HIV+ group than in the control individuals (p < 0.001), while no differences among groups were detected in HRV parameters during the tilt test. CONCLUSIONS: Despite ART regimens, HIV+ patients presented lower cardiac vagal modulation than controls, whereas no difference was observed among the HIV groups, suggesting that higher cardiovascular risk linked to PIs may be associated with factors other than autonomic dysfunction.

Baroreflex dysfunction in Parkinson's disease: integration of central and peripheral mechanisms.

The incidence of Parkinson's disease (PD) is increasing worldwide. Although the PD hallmark is the motor impairments, nonmotor dysfunctions are now becoming more recognized. Recently, studies have suggested that baroreflex dysfunction is one of the underlying mechanisms of cardiovascular dysregulation observed in patients with PD. However, the large body of literature on baroreflex function in PD is unclear. The baroreflex system plays a major role in the autonomic, and ultimately blood pressure and heart rate, adjustments that accompany acute cardiovascular stressors on a daily basis. Therefore, impaired baroreflex function (i.e., decreased sensitivity or gain) can lead to altered neural cardiovascular responses. Since PD affects parasympathetic and sympathetic branches of the autonomic nervous system and both are orchestrated by the baroreflex system, understanding of this crucial mechanism in PD is necessary. In the present review, we summarize the potential altered central and peripheral mechanisms affecting the feedback-controlled loops that comprise the reflex arc in patients with PD. Major factors including arterial stiffness, reduced number of C1 and activation of non-C1 neurons, presence of central α-synuclein aggregation, cardiac sympathetic denervation, attenuated muscle sympathetic nerve activity, and lower norepinephrine release could compromise baroreflex function in PD. Results from patients with PD and from animal models of PD provide the reader with a clearer picture of baroreflex function in this clinical condition. By doing so, our intent is to stimulate future studies to evaluate several unanswered questions in this research area.

Improving the prognosis of renal patients: The effects of blood flow-restricted resistance training on redox balance and cardiac autonomic function.

NEW FINDINGS: What is the central question of this study? Can resistance training with and without blood flow restriction improve redox balance and positively impact the autonomic cardiac modulation in chronic kidney disease patients? What is the main finding and its importance? Resistance training with and without blood flow restriction improved antioxidant defence (paraoxonase 1), decreased the pro-oxidative myeloperoxidase, improved cardiac autonomic function and slowed the decrease in renal function. We draw attention to the important clinical implications for the management of redox balance and autonomic cardiac function in chronic kidney disease patients. ABSTRACT: Patients with chronic kidney disease (CKD) are prone to cardiovascular diseases secondary to abnormalities in both autonomic cardiac function and redox balance [myeloperoxidase (MPO) to paraoxonase 1 (PON1) ratio]. Although aerobic training improves both autonomic balance and redox balance in patients with CKD, the cardioprotective effects of resistance training (RT), with and without blood flow restriction (BFR), remain unknown. We aimed to compare the effects of RT and RT+BFR on antioxidant defence (PON1), pro-oxidative status (MPO), cardiac autonomic function (quantified by heart rate variability analysis) and renal function. Conservative CKD (stages 1 to 5 who do not need hemodialysis) patients (n = 105, 33 female) of both sexes were randomized into three groups: control (CTL; 57.6 ± 5.2 years; body mass index, 33.23 ± 1.62 kg/m2 ), RT (58.09 ± 6.26 years; body mass index 33.63 ± 2.05 kg/m2 ) and RT+BFR (58.06 ± 6.47 years; body mass index, 33.32 ± 1.87 kg/m2 ). Patients completed 6 months of RT or RT+BFR on three non-consecutive days per week under the supervision of strength and conditioning professionals. Training loads were adjusted every 2 months. Heart rate variability was recorded with a Polar-RS800 and data were analysed for time and frequency domains using Kubios software. The redox balance markers were PON1 and MPO, which were analysed in plasma samples. Renal function was estimated as estimated glomerular filtration rate. The RT and RT+BFR decreased pro-oxidative MPO (RT, ∼34 ng/ml and RT+BFR, ∼27 ng/ml), improved both antioxidant defence (PON1: RT, ∼23 U/L and RT+BFR, ∼31 U/L) and cardiac autonomic function (R-R interval: RT, ∼120.4 ms and RT+BFR, ∼117.7 ms), and slowed the deterioration of renal function (P < 0.0001). Redox balance markers were inversely correlated with heart rate variability time-domain indices. Our data indicated that both training models were effective as non-pharmacological tools to increase the antioxidant defences, decrease oxidative stress and improve the cardiac autonomic function of CKD patients.

Exercise Enhances the Effect of Bariatric Surgery in Markers of Cardiac Autonomic Function.

BACKGROUND: Bariatric surgery improves cardiovascular health, which might be partly ascribed to beneficial alterations in the autonomic nervous system. However, it is currently unknown whether benefits from surgery on cardiac autonomic regulation in post-bariatric patients can be further improved by adjuvant therapies, namely exercise. We investigated the effects of a 6-month exercise training program on cardiac autonomic responses in women undergoing bariatric surgery. METHODS: Sixty-two women eligible for bariatric surgery were randomly allocated to either standard of care (control) or an exercise training intervention. At baseline (PRE) and 3 (POST3) and 9 (POST9) months after surgery, we assessed chronotropic response to exercise (CR%; i.e., percentage change in heart rate from rest to peak exercise) and heart rate recovery (HRR30s, HRR60s, and HRR120s; i.e., decay of heart rate at 30, 60, and 120 s post exercise) after a maximal exercise test. RESULTS: Between-group absolute changes revealed higher CR% (Δ = 8.56%, CI95% 0.22-19.90, P = 0.04), HRR30s (Δ = 12.98 beat/min, CI95% 4.29-21.67, P = 0.01), HRR60s (Δ = 22.95 beat/min, CI95% 11.72-34.18, P = 0.01), and HRR120s (Δ = 34.54 beat/min, CI95% 19.91-49.17, P < 0.01) in the exercised vs. non-exercised group. CONCLUSIONS: Our findings demonstrate that exercise training enhanced the benefits of bariatric surgery on cardiac autonomic regulation. These results highlight the relevance of exercise training as a treatment for post-bariatric patients, ensuring optimal cardiovascular outcomes.

Exercise training ameliorates adrenergic control in spontaneously hypertensive rats.

The goal of this study was to examine vascular control after sympathetic stimulation by tyramine infusion in hypertensive rats submitted to swimming training. To this end, male rats were assigned to the following groups: sedentary (SN) and trained normotensive (TN), sedentary (SH) and trained hypertensive (TH). Arterial pressure (AP), heart rate (HR), HR variability (HRV), AP variability (APV), and cardiac autonomic function were recorded. Following, infusion of tyramine was administrated. The TN and TH showed a lower resting HR compared with their respective sedentary groups (p < .05). Pressure levels were less in TH than SH (p < .05). The TH showed a higher HRV together with a lower APV in comparison to SH (p < .05). The sympathetic modulation of HRV and APV was lower in TH than in SH (p < .05). Both trained groups presented an increased parasympathetic modulation of HRV compared with their respective sedentary groups (p < .05). The TN and TH groups had a higher vagal effect in comparison with their respective sedentary groups (p < .001). The sympathetic effect was lower in TH than in SH (p < .001). Pressor and HR responses to tyramine in different doses were attenuated in TH (p < .001). Further analysis showed a significant association between infusion of tyramine and normalized LF component of HRV (r = 0.84, p < .001), systolic APV (r = 0.58, p < .001) and diastolic APV (r = 0.49, p < .001). In conclusion, exercise training provokes less pressor response variation by tyramine infusion in hypertensive animals suggesting sympathetic nerve endings adjustments and decrease of the vasoconstrictor effect attenuates injury caused by hypertension improving cardiovascular autonomic dysfunction, which can be associated with sympathetic attenuation.

[Effect of ultrasound-guided right stellate ganglion block on perioperative atrial fibrillation in patients undergoing lung lobectomy: a randomized controlled trial]. / Efeito do bloqueio do gânglio estrelado direito guiado por ultrassom na fibrilação atrial perioperatória em pacientes submetidos a lobectomia pulmonar: estudo controlado randomizado.

OBJECTIVE: To observe the effects of preoperative right stellate ganglion block on perioperative atrial fibrillation in patients undergoing lung lobectomy. METHODS: Two hundred patients who underwent a scheduled lobectomy were randomly divided into the S and C groups. The S group was injected with 4mL of 0.2% ropivacaine under ultrasound guidance, and the C group did not receive stellate ganglion block. The patients underwent continuous ECG monitoring, and the incidences of atrial fibrillation and other types of arrhythmias were recorded from the start of surgery to 24hours after surgery. RESULTS: The respective incidences of atrial fibrillation in the S group and the C group were 3% and 10% (p=0.045); other atrial arrhythmias were 20% and 38% (p=0.005); and ventricular arrhythmia were 28% and 39% (p=0.09). CONCLUSIONS: The results of the study indicated that preoperative right stellate ganglion block can effectively reduce the incidence of intraoperative and postoperative atrial fibrillation.

Autonomic function may not modulate irisin release in healthy adults: findings from a randomized cross-over study

ABSTRACT Objective Autonomic nervous system, especially the sympathetic nervous system, may stimulate the expression of peroxisome proliferator-activated receptor γ coactivator-1α, which regulates irisin. This study aimed to explore whether there was any association between autonomic function as assessed by heart rate related indices and irisin release following acute exercise. Subjects and methods Seventeen healthy adults were asked to perform an incremental exhaustive cycling as well as an incremental exhaustive running separately on different days. Heart rate was monitored, and blood samples were collected before, immediately, 10-, and 60-minutes post-exercise. Serum irisin was measured using ELISA kit. Results Markers for autonomic function, such as heart rate at rest, peak, or recovery, heart rate reserve, heart rate recovery, and chronotropic index, were comparable between cycling and running (all P > 0.10). Irisin was increased immediately following both exercise. No significant association was observed between heart rate at rest, peak, or recovery and irisin level at the corresponding time-point, as well as between heart rate reserve, heart rate recovery, or chronotropic index and exercise induced irisin release, with or without controlling for age, body mass index, and glucose (all P > 0.10). Conclusions Autonomic function might not be associated with irisin release in healthy adults. Arch Endocrinol Metab. 2020;64(3):201-4

Effect of ultrasound-guided right stellate ganglion block on perioperative atrial fibrillation in patients undergoing lung lobectomy: a randomized controlled trial / Efeito do bloqueio do gânglio estrelado direito guiado por ultrassom na fibrilação atrial perioperatória em pacientes submetidos a lobectomia pulmonar: estudo controlado randomizado

Abstract Objective: To observe the effects of preoperative right stellate ganglion block on perioperative atrial fibrillation in patients undergoing lung lobectomy. Methods: Two hundred patients who underwent a scheduled lobectomy were randomly divided into the S and C groups. The S group was injected with 4 mL of 0.2% ropivacaine under ultrasound guidance, and the C group did not receive stellate ganglion block. The patients underwent continuous ECG monitoring, and the incidences of atrial fibrillation and other types of arrhythmias were recorded from the start of surgery to 24 hours after surgery. Results: The respective incidences of atrial fibrillation in the S group and the C group were 3% and 10% (p = 0.045); other atrial arrhythmias were 20% and 38% (p = 0.005); and ventricular arrhythmia were 28% and 39% (p = 0.09). Conclusions: The results of the study indicated that preoperative right stellate ganglion block can effectively reduce the incidence of intraoperative and postoperative atrial fibrillation.

Resumo Objetivo: Observar os efeitos do bloqueio do gânglio estrelado na fibrilação atrial no período perioperatório em pacientes submetidos a lobectomia pulmonar. Método: Duzentos pacientes programados para lobectomia foram divididos aleatoriamente nos grupos S e C. O grupo S recebeu infusão de 4 mL de ropivacaína a 0,2% orientada por ultrassom e o grupo C não foi submetido a bloqueio do gânglio estrelado. Os pacientes foram submetidos à monitoração contínua de ECG, e as incidências de fibrilação atrial e outros tipos de arritmias foram registradas do início da cirurgia até 24 horas depois da cirurgia. Resultados: As incidências de fibrilação atrial no grupo S e no grupo C foram 3% e 10%, respectivamente (p = 0,045); as de outras arritmias atriais foram 20% e 38% (p = 0,005); e de arritmias ventriculares, 28% e 39% (p = 0,09). Conclusões: Os resultados do estudo indicaram que o bloqueio do gânglio estrelado no pré-operatório pode ser efetivo na redução da incidência de fibrilação atrial nos períodos intra- e pós-operatório.

Early weaning alters the thermogenic capacity of brown adipose tissue in adult male and female rats.

PURPOSE: Early weaning (EW) is a risk factor for obesity development. Brown adipose tissue (BAT) hypofunction is related to obesity onset. Here, we evaluated whether sympathetic nervous system (SNS) activity in BAT and the thermogenic function of BAT are decreased in adulthood in obese rats from two EW models. METHODS: At the time of birth, lactating Wistar rats and their pups (three males and three females) were separated into three groups: the control group, in which pups consumed milk throughout lactation; the non-pharmacological EW (NPEW) group, in which suckling was interrupted with a bandage during the last 3 days of lactation; and the pharmacological EW (PEW) group, in which dams were treated with bromocriptine (0.5 mg/twice a day) 3 days before weaning. The offspring were sacrificed on PN180. RESULTS: Adult male rats from both EW models exhibited lower BAT SNS activity. Female rats from the PEW group showed a decrease in BAT SNS activity. The protein levels of UCP1 were lower in the NPEW males, while PGC1α levels were lower in both PEW and NPEW males. Both groups of EW females showed reductions in the levels of ß3-AR, TRß1, and PGC1α. The UCP1 protein level was reduced only in the NPEW females. The EW groups of both sexes had lower AMPK protein levels in BAT. In the hypothalamus, only the PEW females showed an increase in AMPK protein levels. In both groups of EW males, adrenal catecholamine was increased and tyrosine hydroxylase was decreased, while in EW females, adrenal catecholamine was decreased. CONCLUSIONS: Early weaning alters the thermogenic capacity of BAT, which partially contributes to obesity in adulthood, and there are sex-related differences in these alterations.

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

BACKGROUND: Both increased carotid intima-media thickness (cIMT) and low heart rate variability (HRV) have been associated with cardiovascular mortality and morbidity. Thus, the aim of this study was to investigate whether cardio autonomic alterations are accompanied or not by subclinical atherosclerosis in participants of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil). METHODS: cIMT measures and 5-min HRV analyses were performed in apparently healthy adults. Heart rate variability was evaluated by linear time and frequency domain analyses. cIMT was defined as the average between the mean left and mean right cIMT values and was analysed as continuous and categorized variables (P≥75 or P<75). Multiple linear models using continuous variables and multivariate logistic regression with categorized cIMT and HRV quartiles were performed. RESULTS: Out of 7256 participants eligible for analyses, 23·4% presented cIMT ≥ 75th percentile. Heart rate variability variables were reduced in cIMT ≥ P75 in comparison with cIMT < P75: SDNN 33·0 versus 37·0 ms, P<0·001; RMSSD 22·0 versus 26·0 ms, P<0·001; LF 191·0 versus 260·0 ms2 , P<0·001; HF 164·0 versus 238·5 ms2 , P<0·001. In crude analysis, an increased odds ratio for cIMT ≥ P75 was verified within the lowest two quartiles of LF and HF, but significances did not remain after adjustments for anthropometric and clinical variables. CONCLUSIONS: Considering the entire sample, subjects with cIMT ≥ P75 presented lower HRV values, but no independent relationships were detected between cIMT and HRV after multivariate adjustment.

Symbolic analysis of heart rate fluctuations identifies cardiac autonomic modifications during LPS-induced endotoxemia.

The present study aimed to compare linear and symbolic dynamics (SD) indices for detecting the autonomic cardiac changes produced by endotoxemia in freely-moving rats. In this context, we analyzed ECG-derived R-R time series in freely moving Dark Agouti rats, which received lipopolysaccharide (LPS, n = 9), or vehicle (V, n = 7). Five minutes R-R time series were assessed every hour up to +12 h and + 24 h post-LPS injection. We found that SD indices showed significant differences at +7 h between V vs. LPS groups and at +9 h between basal levels of LPS (-3 h) and post-LPS injection (pre-LPS vs. post-LPS). In general, SD seems more appropriate than linear indices to evaluate the autonomic changes of endotoxemic rats. Overall, the symbolic parameters detected decreased R-R variability and complexity, which indicate a modification of the autonomic regulation during LPS-induced endotoxemia. This modification is probably related to a reduced activity of the cholinergic anti-inflammatory pathway at the long term.