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Background: Despite reported physical and functional improvements with aerobic and sprint interval training (SIT) protocols in individuals with intellectual disability (ID), it is not known if these interventions' effectivity would promote improvements in cardiac autonomic modulation. This study aimed to investigate if a 6-month SIT or a continuous aerobic programme could enhance physical performance and cardiac autonomic modulation at rest, during physical activity (PA) and after it in older adults with an ID., Methods: This is a randomised control trial. Participants with ID (age: 50.58 ± 7.25) were allocated to one of three groups [multicomponent aerobic training group (MATG), multicomponent interval sprint training group (MISTG) and control group (CG)]. The programmes lasted 24 weeks, with three sessions/week, 75-90 min per session. The HRV was analysed at rest and recovery, the delta of heart rate (HR) was analysed during 6MWT, and the HR t-off kinetics was analysed in recovery after 6MWT., Results: There were not found differences between groups, moments, or interaction for cardiac autonomic modulation at rest and recovery. During exercise, only MSITG showed a significant increase of HR between rest and the first 30 s of exercise (P < 0.05). Physical performance increased only in MSITG (P < 0.05), while CG showed a significant reduction (P < 0.01)., Conclusions: The MSITG improved the physical performance and the vagal withdrawal at the beginning of the submaximal exercise. These findings suggest that high-intensity exercise may positively impact baroreflex function, mitigating the decline in autonomic reflex response capacity associated with aging in individuals with ID., (© 2024 The Author(s). Journal of Intellectual Disability Research published by John Wiley & Sons and MENCAP.)

Objective: The present study sought to expand upon prior investigations of the relationship between the post-exercise heart rate recovery (HRR) and the cardiac autonomic responsiveness after orthostatic stress test. Method: HRR at the 1st, 3rd, and 5th min after maximal exercise test were correlated with relative change ( Δ %) of time-domain (CV, pNN50, and rMSSD) and frequency-domain (TP, LF, HF, and LF/HF ratio) indices of heart rate variability (HRV) after active orthostatic test in 46 healthy men. Statistical analysis employed non-parametric tests with a p-value set at 5%. Results: HRR at 1st min correlated with Δ %pNN50 (r s :0.36 - p  = .02). In the 3rd and 5th min, these measures correlated with Δ %pNN50, Δ %rMSSD, Δ %CV, Δ %TP, and Δ %HF indices (r s :0.33, 0.59 - p  ≤ .05). Coefficient of HRR at the 1st min correlated with Δ %pNN50, Δ %rMSSD, and Δ %HF (r s :0.28, 0.45 - p  ≤ .05). The 3rd and 5th min showed correlation with Δ %pNN50, Δ %rMSSD, Δ %HF, Δ %CV, and Δ %TP (r s :0.37, 0.64 - p  ≤ .05). No correlation was found with indices combined sympathetic-parasympathetic modulation and HRR. After the sample was divided into high and low parasympathetic responsiveness subgroups after the orthostatic test, faster HRR was associated with the degree of parasympathetic responsiveness (reduction) following postural change ( p  ≤ .05). Conclusion: HRR throughout the 1st to 5th min is positively correlated with parasympathetic responsiveness and overall cardiac autonomic modulation of HRV after the orthostatic stress test, and faster HRR is positively correlated with the relative degree of parasympathetic responsiveness after the active postural change at rest in healthy men.

Background: Although cardiac autonomic modulation has been studied in several respiratory diseases, the evidence is limited on lung transplantation, particularly on its acute and chronic effects. Thus, we aimed to evaluate cardiac autonomic modulation before and after bilateral lung transplantation (BLT) through a prospective study on patients enrolled while awaiting transplant., Methods: Twenty-two patients on the waiting list for lung transplantation (11 women, age 33 [24-51] years) were enrolled in a prospective study at Ospedale Maggiore Policlinico Hospital in Milan, Italy. To evaluate cardiac autonomic modulation, ten minutes ECG and respiration were recorded at different time points before (T0) and 15 days (T1) and 6 months (T2) after bilateral lung transplantation. As to the analysis of cardiac autonomic modulation, heart rate variability (HRV) was assessed using spectral and symbolic analysis. Entropy-derived measures were used to evaluate complexity of cardiac autonomic modulation. Comparisons of autonomic indices at different time points were performed., Results: BLT reduced HRV total power, HRV complexity and vagal modulation, while it increased sympathetic modulation in the acute phase (T1) compared to baseline (T0). The HRV alterations remained stable after 6 months (T2)., Conclusion: BLT reduced global variability and complexity of cardiac autonomic modulation in acute phases, and these alterations remain stable after 6 months from surgery. After BLT, a sympathetic predominance and a vagal withdrawal could be a characteristic autonomic pattern in this population.

Introduction: Successful regulation of emotional states is positively associated to mental health, while difficulties in regulating emotions are negatively associated to overall mental health and in particular associated with anxiety or depression symptoms. A key structure associated to socio-emotional regulatory processes is the central autonomic network. Activity in this structure is associated to vagal activity can be indexed noninvasively and simply by measures of peripheral cardiac autonomic modulations such as heart rate variability. Vagal activity exhibits a circadian variation pattern, with a maximum during nighttime. Depression is known to affect chronobiology. Also, depressive symptoms are known to be associated with decreased resting state vagal activity, but studies investigating the association between circadian variation pattern of vagal activity and depressive symptoms are scarce. We aim to examine these patterns in association to symptom severity of depression using chronobiologic methods., Methods: Data from the Manheim Industrial Cohort Studies (MICS) were used. A total of 3,030 predominantly healthy working adults underwent, among others, ambulatory 24-h hear rate-recordings, detailed health examination and online questionnaires and were available for this analysis. The root mean sum of successive differences (RMSSD) was used as an indicator of vagally mediated heart rate variability. Three individual-level cosine function parameters (MESOR, amplitude, acrophase) were estimated to quantify circadian variation pattern. Multivariate linear regression models including important covariates such as age, sex, and lifestyle factors as well as an interaction effect of sex with depressive symptoms were used to estimate the association of circadian variation pattern of vagal activity with depressive symptoms simultaneously., Results: The analysis sample consisted of 20.2% females and an average age 41 with standard deviation of 11 years. Nonparametric bivariate analysis revealed significant MESOR and amplitude differences between the 90 th percentile split, but not on acrophase. Multivariate linear regression models estimated depressive symptoms to be negatively associated with the 24h mean (MESOR) and oscillation amplitude in men but positively associated in women. This pattern of findings indicates a blunted day-night rhythm of vagal activity in men with greater depressive symptoms as well as a moderation effect of sex in the association of CVP and depressive symptoms., Conclusions: This is the first study investigating circadian variation pattern by mild depressive symptoms in a large, rather healthy occupational sample. Depressive symptoms were associated with decreased circadian variation pattern of vagal activity in men but with increased circadian variation pattern in women. The possible underlying mechanism(s) are discussed using the neurovisceral integration model. These findings may have implications for the knowledge on etiology, diagnosis, course, and treatment of depressive symptoms and thus may be of significant public health relevance.

Background: Patients with chronic Chagas cardiopathy (CCC), which may be associated with cardiac arrhythmias, frequently use amiodarone, an antiarrhythmic drug that, experimentally, appears to modulate the cardiac autonomic function., Objective: The present cross-sectional observational study aimed to evaluate autonomic cardiac modulation in patients with CCC undergoing chronic amiodarone therapy., Methods: Three groups were investigated: Group 1 included patients with CCC not treated with amiodarone (n = 27); Group 2 included patients with CCC with prolonged use (at least 6 months) of amiodarone (n = 16); and Group 3 included non-Chagasic control patients (n = 23). All patients underwent a complete clinical and laboratory assessment, followed by autonomic function tests, consisting of a basal continuous electrocardiogram in the resting supine position for 10 minutes, followed by a change the orthostatic posture for a further 5 minutes. Heart rate variability (HRV) parameters (median and interquartile interval) were quantified using linear methods in the time- and frequency-domains (autoregressive spectral analysis) and nonlinear methods, including symbolic analysis., Results: Patients with CCC using amiodarone had changes in HRV suggestive of an offset in the sympatho-vagal balance with a vagal modulation predominance (normalized HF, 49.7[27.4] vs 31.1[22.8] [P < 0.05]; and percentage 2V, 40.1 [14.6] vs 21.5 [13.4] [P < 0.05] vs untreated CCC group). These changes were further accompanied by increases in parameters indicative of greater complexity of HRV., Conclusions: The deviation in the sympatho-vagal balance and the increase in the complexity of HRV strongly suggest that amiodarone may have a cardioprotective effect, in addition to its antiarrhythmic effects, which could increase the survival of these patients., (© 2018 Wiley Periodicals, Inc.)

Recent studies indicate that migraine is associated with increased risk of cardiovascular diseases. However, links between autonomic cardiovascular regulation, arterial hypertension (AH) and migraine are still little explored. In this study, we evaluated autonomic regulation in migraine patients with and without hypertension. We studied 104 patients with migraine, aged 34±10 y, including 28 with and 76 without hypertension (M+AH and M-AH groups, respectively). The control group consisted of 88 healthy volunteers matched by age and sex. The autonomic regulation of circulation was examined with the tilt-table test, deep-breathing and Valsalva Maneuver, handgrip test, cold-stress induced vasoconstriction, arterial baroreflex, and blood pressure variability measurements. We found that migraine patients with concomitant hypertension demonstrated reduced arterial baroreflex, whereas other parameters of cardiac autonomic regulation were unchanged. In contrast, most indicators of vasomotor reactivity (blood pressure response to the hand-grip, Valsalva maneuver and cold vasoconstriction) were enhanced in migraine patients with no significant differences between migraine patients with and without hypertension. Patients from both M+AH and M-AH groups more commonly had a family history of cardiovascular disorders. Our data revealed increased vasomotor reactivity in migraine patients, with or without concomitant hypertension. This was associated with the family history of cardiovascular diseases., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Objective: Changes in autonomic modulation are found in depressive patients. QT dispersion is a convenient measure of cardiac autonomic modulation (CAM). As both QT dispersion and depression are related to changes in CAM, this study aimed to examine if there was an association between depression severity and QT dispersion., Methods: The selected sample (n=60) derived from 236 women who were recruited via a campaign for breast cancer prevention. The women selected to participate were all non-smokers and were not taking any drug that could interfere with the results. After applying inclusion and exclusion criteria, 60 women were selected. QT dispersion (QTd) and rate-corrected QTd (QTcD) were calculated in 37 physically and mentally healthy women and 23 nontreated depressive women. Univariate ANOVA(s) were used to test group differences. The 17-item Hamilton Depression Rating Scale (HDRS17) was scored to measure depression severity. The relationship between depression severity and cardiac autonomic modulation was analyzed by the best curve that fit the raw data of the HDRS17 scores and the QT dispersion variables., Results: The QTd and QTcD were significantly smaller in non-depressed in relation to the depressed women. The best curve that fit the raw data of depression severity (HDRS17) and the two measurements of cardiac autonomic modulation (QTd and QTcD) was a cubic equation for both QTd and QTcD. An increase in QTd and QTcD were observed until the HDRS17 score reached 20 points., Conclusion: There is a significant positive relationship between depression severity and cardiac autonomic modulation in mild and moderate depression., (Copyright © 2016. Published by Elsevier Inc.)

Fine particulate matter (PM2.5) is one of the major pollutants in metropolitan areas. The current study was conducted to observe the effects of PM2.5 on cardiac autonomic modulation. The participants included 619 men and women aged from 35-75 in a residential area in Shanghai, China. All the participants were divided into four categories according to the distance between their apartments and major road. In addition, individual PM2.5 was measured using SIDEPAKTM AM510 (TSI, USA) from 8:00 am to 6:00 pm. At the end of the individual PM2.5 measurement, the systolic pressure, diastolic pressure, heart rate (HR), low-frequency (LF), high-frequency (HF), and LF/HF were determined. The association between individual PM2.5 level and the above health effects was analyzed using generalized linear regression. The results showed that the average concentration of individual PM2.5 was 95.5 and 87.0 μg/m(3) for men and women. Residential distance to major road was negatively correlated with the individual PM2.5. The results indicated that per 1.0 μg/m(3) increase of individual PM2.5 was associated with a 2.3 % increase for systolic pressure, 0.3 % increase for diastolic pressure, 0.4 % decrease for LF, and 0.4 % decrease for HF. Nevertheless, there was no statistical association between individual PM2.5 and heart rate and LF/HF in the total model. In addition, the similar results were found in men and women excluding a significant association between PM2.5 and the heart rate in men. The alterations of cardiac autonomic modulation hinted that PM2.5 exposure might be associated with the potential occurrence of cardiovascular disease, such as arrhythmia and ischemic heart diseases.

Background: No study to date has investigated longitudinal trajectories of cardiac autonomic modulation changes with aging; therefore, we lack evidence showing whether these changes occur naturally or are secondary to disease or medication use. This study tested whether heart rate variability (HRV) trajectories from middle to older age are largely normative or caused by pathological changes with aging in a large prospective cohort. We further assessed whether HRV changes were modified by socioeconomic status, ethnicity, or habitual physical activity., Methods and Results: This study involved 3176 men and 1238 women initially aged 44 to 69 years (1997-1999) from the UK Whitehall II population-based cohort. We evaluated time- and frequency-domain HRV measures of short-term recordings at 3 time points over a 10-year period. Random mixed models with time-varying covariates were applied. Cross-sectionally, HRV measures were lower for men than for women, for participants with cardiometabolic conditions, and for participants reporting use of medications other than beta blockers. Longitudinally, HRV measures decreased significantly with aging in both sexes, with faster decline in younger age groups. HRV trajectories were not explained by increased prevalence of cardiometabolic problems and/or medication use. In women, cardiometabolic problems were associated with faster decline in the standard deviation of all intervals between R waves with normal-to-normal conduction, in low-frequency HRV, and in low-frequency HRV in normalized units. Socioeconomic status, ethnicity, and habitual physical activity did not have significant effects on HRV trajectories., Conclusions: Our investigation showed a general pattern and timing of changes in indices of cardiac autonomic modulation from middle to older age. These changes seem likely to reflect the normal aging process rather than being secondary to cardiometabolic problems and medication use., (© 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.)

Background: This study aimed to evaluate the effects of aerobic exercise on cardiac autonomic modulation in women with polycystic ovary syndrome (PCOS)., Methods: Thirty women with PCOS (25.8±4.8 years old; body mass index, BMI≥25 kg/m2) were divided into two groups; exercise group (n=15) and control group (n=15). R-R interval was recorded during 15-min at rest in the supine position. Heart rate variability (HRV) was analyzed by linear (rMSSD, SDNN, LF, HF, LFnu, HFnu, and LF/HF) and nonlinear methods (Shannon entropy, SE; symbolic analyses, 0 V%, 1 V%, 2LV%, and 2UV%) at baseline and after 16 weeks. The multivariate analysis of covariance was used to analyze the effects of exercise on HRV indexes, adjusted for changes in BMI, fasting insulin, and testosterone level., Results: The exercise group increased parasympathetic modulation (rMSSD, HF, HFnu, 2UV%; (p<0.05)) and decreased sympathetic modulation (LF, LFnu, 0 V%; (p<0.05)) independently of changes in BMI, fasting insulin, and testosterone level. Moreover, the exercise group decreased resting HR and systolic blood pressure (p<0.05). All parameters remained unchanged in the control group., Conclusions: Aerobic exercise increased vagal modulation and decreased sympathetic modulation in women with PCOS. This finding reinforces the recommendations for exercise during the clinical management of these patients., (Copyright © 2015. Published by Elsevier Ireland Ltd.)

Objective: To investigate the effects of objectively measured habitual sleep patterns on cardiac autonomic modulation (CAM) in a population-based sample of adolescents., Methods: We used data from 421 adolescents who completed the follow-up examination in the Penn State Children Cohort study. CAM was assessed by heart rate (HR) variability (HRV) analysis of beat-to-beat normal R-R intervals from a 39-h electrocardiogram, on a 30-min basis. The HRV indices included frequency domain (HF, LF, and LF/HF ratio), and time domain (SDNN, RMSSD, and heart rate or HR) variables. Actigraphy was used for seven consecutive nights to estimate nightly sleep duration and time in bed. The seven-night mean (SD) of sleep duration and sleep efficiency were used to represent sleep duration, duration variability, sleep efficiency, and efficiency variability, respectively. HF and LF were log-transformed for statistical analysis. Linear mixed-effect models were used to analyze the association between sleep patterns and CAM., Results: After adjusting for major confounders, increased sleep duration variability and efficiency variability were significantly associated with lower HRV and higher HR during the 39-h, as well as separated by daytime and nighttime. For instance, a 1-h increase in sleep duration variability is associated with -0.14(0.04), -0.12(0.06), and -0.16(0.05) ms(2) decrease in total, daytime, and nighttime HF, respectively. No associations were found between sleep duration, or sleep efficiency and HRV., Conclusion: Higher habitual sleep duration variability and efficiency variability are associated with lower HRV and higher HR, suggesting that an irregular sleep pattern has an adverse impact on CAM, even in healthy adolescents., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Unemployment has consistently been associated with increased risk of cardiovascular disease and premature mortality, and impaired autonomic modulation of the heart might be one mechanism partly explaining this. This study examined whether the possible effect of unemployment on cardiac autonomic modulation is in part mediated by lower psychological well-being. The sample comprised of 15 job-seeking men aged 30-49 years matched with 15 employed men on age, type of job, smoking habits, alcohol intake, frequency of physical activity, and body mass index. Heart rate variability (HRV) during a modified orthostatic test was the measure of cardiac autonomic modulation, and life satisfaction was the measure of psychological well-being. Unemployed men had significantly lower overall HRV (p = .040) than controls. This association was partially mediated through lower general life satisfaction, and in particular, by low financial satisfaction, independently of demographic and/or behavioral factors that influence HRV. These findings suggest that seeking a job is a potential stressor that may reduce overall HRV and contribute towards disturbance of cardiac autonomic modulation in men. Financial difficulties could be one mechanism through which the effects of unemployment are translated into impaired autonomic modulation.

Background: Vasovagal syncope (VVS) is the result of an autonomic reflex that has a final effect of reducing sympathetic drive and increasing vagal activity. However, whether syncopal symptoms are associated with pathological cardiac autonomic modulation is not fully known. We tested the hypothesis that cardiac autonomic function is impaired in patients with VVS., Methods: Eighty-four consecutive patients (59 males; 48.8 ± 20.9 years) with recurrent unexplained syncope were enrolled. The head-up tilt test (HUTT) was positive in 38 patients and negative in 46 patients. Cardiac autonomic function was assessed by baroreflex sensitivity (BRS), heart rate variability, plasma concentrations of norepinephrine, and (123) I-metaiodobenzylguanidine (MIBG) scintigraphy., Results: BRS indices were significantly lower in the HUTT-positive group than in the HUTT-negative group (6.1 ± 5.5 mm Hg/s vs 9.8 ± 7.6 mm Hg/s, P = 0.02). With regard to cardiac (123) I-MIBG scintigraphy, the mean heart-to-mediastinum ratio at the delayed phase tended to be lower in HUTT-positive than in HUTT-negative individuals, but this difference was not significant (2.75 ± 0.55 vs 3.02 ± 0.49, P = 0.08).The percent washout rate of (123) I-MIBG was significantly higher in the positive group compared with the negative group (40.7 ± 13.1% vs 31.5 ± 13.3%, P = 0.02). Multivariate logistic analysis revealed that the appearance of HUTT-induced VVS was predicted independently by a high percent washout rate of (123) I-MIBG (odds ratio, 0.954; 95% confidence interval, 0.903-0.998; P = 0.048)., Conclusions: Our results suggest that pathological autonomic cardiac modulation may play a role in the appearance of syncope in VVS patients., (©2014 Wiley Periodicals, Inc.)

The autonomic nervous system (ANS) is modulated by sleep and wakefulness. Noninvasive assessment of cardiac ANS with heart rate variability (HRV) analysis is a window for monitoring malfunctioning of cardiovascular autonomic modulation due to sleep deprivation. This study represents the first investigation of dynamic ANS effects and of electrophysiological and subjective sleepiness, in parallel, during 40 h of prolonged wakefulness under constant routine (CR) conditions. In eleven young male healthy subjects, ECG, EEG, EOG, and EMG chin recordings were performed during baseline sleep, during 40 h of sleep deprivation, and during recovery sleep. After sleep deprivation, slow-wave sleep and sleep efficiency increased, whereas HRV - global variability and HRV sympathovagal balance - was reduced (all p<0.05). Sleep-stage-dependent analysis revealed reductions in the sympathovagal balance only for NREM sleep stages (all p<0.05). Comparison of the daytime pattern of CR day one (CR baseline) with that of CR day two (CR sleep deprivation) disclosed an increase in subjective sleepiness, in the amount of unintended sleep, and in HRV sympathovagal balance, with accompaniment by increased EEG alpha attenuation (all p<0.05). Circadian rhythm analysis revealed the strongest influence on heart rate, with less influence on HRV sympathovagal balance. Hour-by-hour analysis disclosed the difference between CR sleep deprivation and CR baseline for subjective sleepiness at almost every single hour and for unintended sleep particularly in the morning and afternoon (both p<0.05). These findings indicate that 40 h of prolonged wakefulness lead in the following night to sleep-stage-dependent reduction in cardiac autonomic modulation. During daytime, an increased occurrence of behavioral and physiological signs of sleepiness was accompanied by diminished cardiac autonomic modulation. The observed changes are an indicator of autonomic stress due to sleep deprivation - which, if chronic, could potentially increase cardiovascular risk., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Heart rate variability (HRV) has shown potential as a tool for monitoring thermal strain, but there is limited data to support its efficacy in older adults during prolonged heat exposures. We compared HRV between young (19–31 years, n = 20) and older (61–78 years, n = 39) adults during 9 h of heat exposure (40 °C, 9% RH). We also explored whether heart rate (HR) and/or HRV could be used to distinguish older adults who achieved elevated thermal strain, defined as either (1) an increase in core temperature >1.0 °C (occurring in 39%, 15/39) or (2) a reduction in systolic blood pressure >10 mm Hg (occurring in 67%, 26/39). Percentage of age-predicted maximal HR and percentage of heart rate reserve (HRR) were higher, whereas standard deviation of normal RR intervals, the square root of the mean of squared differences between successive RR intervals (RMSSD), high frequency power (HF), and cardiac vagal index (CVI) were lower in older compared to young adults during heat exposure (P ≤ 0.004). In older adults, increases in core temperature were correlated with percentage of age-predicted maximal HR, percentage of HRR, RMSSD, and CVI (P ≤ 0.031), whereas changes in systolic blood pressure were not significantly associated with HR or HRV indices (P ≥ 0.327). Receiver operating characteristic curve analysis indicated that HR and HRV indices had generally poor ability to identify older adults with elevated thermal strain (area under the curve ≤0.65). Age-related differences in HRV, consistent with vagal withdrawal among older adults, remained during daylong heat exposure, but marked heterogeneity of response likely contributed to HRV providing limited discriminatory value in identifying changes in core temperature or blood pressure in older adults. [ABSTRACT FROM AUTHOR]

Polycystic ovary syndrome (PCOS) is a complex endocrine and metabolic disorder interrelated with hyperlipidaemia, abdominal obesity, hypertension which are report to be related to sympathetic hyperactivity. The main aim of this study is to determine and compare autonomic status in between PCOS cases and control on the basis of heart rate variability (HRV). This case control study was conducted in RNT Medical College and Attached Group of Hospital, Udaipur (Rajasthan). The sample size of 160 cases of PCOS were included in this study with equal number of the control group. The mean outcomes were the values of HRV in the time (mean RR interval, SDNN, RMSSD, pNN50%) and frequency (Total Power, Low Frequency (LF), LF norm, High Frequency (HF), HF norm and LF/HF ratio) domains. There was significant difference in the values of the time domain (mean RR, SDNN, RMSSD, pNN50%) between the groups. In the frequency domain, women with PCOS showed significantly higher LF (P = <0.001), and LF/HF ratio (P=<0.001) than the control group. HF norm was significantly lower in the women with PCOS than in the controls. This low frequency (LF) indicates sympathetic activity, high frequency (HF) indicates vagal activity and LF/HF ratio indicates sympathovagal balance. The present study concluded sympathovagal imbalance with high sympathetic dominance in women with PCOS. [ABSTRACT FROM AUTHOR]

Background: Generally, in the aging process, there is degradation of autonomic nervous control mechanisms, compromising the regulation of heart rate, which contributes to increased frailty and the risk of falls. This process is defined as a geriatric syndrome that leads to impairment of physiological systems and homeostatic imbalance. Objective: To correlate heart rate variability (HRV), frailty parameters, and the risk of falls in elderly people from a community center. Methods: This research will involve active seniors and participants from the Centro de Convivências de Praia Grande, São Paulo, Brazil. Clinical, demographic, and anthropometric data, psychological variables, and physical conditions will be collected through the International Physical Activity Questionnaire (IPAQ) and the risk of falls test. The heart rate R-R intervals will be analyzed using the H10 polar frequency meter and the HRV application, and transferred to the Kúbios software for further analysis.Results: Two hundred and fourteen participants are involved in this study, 181 (84.6%) of whom are female, 137 (64.0%) are white, with a mean age of 70.27 ± 7.07 years, a weight of 68.37 ± 11.15 kg, and a body mass index of 27.04 ± 4.04 kg/m2. Conclusion: A positive correlation is expected through the stratified analysis of frailty indices, risk of falls, and HRV, suggesting that the lower the HRV, the greater the risk of falls and the greater frailty in the elderly. [ABSTRACT FROM AUTHOR]

This study aimed to assess whether obesity and/or maximal exercise can change 24 h cardiac autonomic modulation and blood pressure in young men. Thirty-nine men (n: 20; 21.9±1.8 kg·m−2 , and n: 19; 32.9±2.4 kg·m−2) were randomly assigned to perform a control (non-exercise) and an experimental day exercise (after maximal incremental test). Cardiac autonomic modulation was evaluated through frequency domain heart rate variability (HRV). Obesity did not impair the ambulatory HRV (p>0.05), however higher diastolic blood pressure during asleep time (p=0.02; group main effect) was observed. The 24 h and awake heart rate was higher on the experimental day (p<0.05; day main effect), regardless of obesity. Hypotension on the experimental day, compared to control day, was observed (p<0.05). Obesity indicators were significantly correlated with heart rate during asleep time (Rho=0.34 to 0.36) and with ambulatory blood pressure(r/Rho=0.32 to 0.53). Furthermore, the HRV threshold workload was significantly correlated with ambulatory heart rate (r/Rho=− 0.38 to−0.52). Finally, ambulatory HRV in obese young men was preserved; however, diastolic blood pressure was increased during asleep time. Maximal exercise caused heart rate increase and 24h hypotension, with decreased cardiac autonomic modulation in the first hour, regardless of obesity. [ABSTRACT FROM AUTHOR]

To analyze whether heart rate variability is reproducible after maximal exercise, 11 men (22.1±3.2 years) performed four incremental exercise tests followed by passive or active recovery. There was high reliability (intraclass coefficient correlation: 0.72–0.96) and fair-to-excellent agreement (coefficient of variation: 7.81–22.09%) in passive recovery, as well as moderate-to-high reliability (intraclass coefficient correlation: 0.50–0.87) and good agreement (coefficient of variation: 11.08–20.89%) in active recovery for LnRMSSD index. There was moderate-to-high reliability (intraclass coefficient correlation: 0.51–0.81) and good agreement (coefficient of variation: 10.41–18.87%) in most of the analyzed time points, in both recovery types for LnSDNN. In both types of recovery, the time domain heart rate variability 5–10 min indices (passive: intraclass coefficient correlation : 0.87–0.88; coefficient of variation: 7.67–13.44%; active: intraclass coefficient correlation 0.59–0.80; coefficient of variation: 14.62–16.26%) presented higher intraclass coefficient correlation and lower coefficient of variation than the spectral heart rate variability indices (passive: intraclass coefficient correlation: 0.71–0.87; coefficient of variation: 12.33–34.21%; active: intraclass coefficient correlation: 0.46–0.77; coefficient of variation: 24.41–105.12%). The LnRMSSD and LnSDNN indices analyzed in 30 s segments and the heart rate variability 5–10 min indices after maximal exercise in untrained healthy men showed satisfactory reproducibility, regardless of the type of recovery, with the time-domain indices showing higher reproducibility than the frequency-domain indices. [ABSTRACT FROM AUTHOR]

This study evaluated the cardiac autonomic modulation after 3 months of exercise in 10 elderly women with low level cognitive function. The subjects were evaluated before and after the 18 wks of physical exercise. The anthropometric and clinical variables showed a significant difference in the body fat (P=0.030), heart rate (P=0.032), and double product (P=0.013). Regarding the variable cognition can be seen that the elderly showed low level cognitive function both pre-exercise and post-exercise. Physical exercise improved the subjects' cardiac autonomic modulation with an increase in the parasympathetic nervous system and a decrease in the sympathetic nervous system. Thus, heart rate was decreased along with double product and body fat. Also, functional capacity was increased in the elderly women with low cognitive function. [ABSTRACT FROM AUTHOR]

Background: The effects of physical therapy on heart rate variability (HRV), especially in children, are still inconclusive. Objective: We investigated the effects of conventional physical therapy (CPT) for airway clearance and nasotracheal suction on the HRV of pediatric patients with acute bronchiolitis. Method: 24 children were divided into two groups: control group (CG, n=12) without respiratory diseases and acute bronchiolitis group (BG, n=12). The heart rate was recorded in the BG at four different moments: basal recording (30 minutes), 5 minutes after the CPT (10 minutes), 5 minutes after nasotracheal suction (10 minutes), and 40 minutes after nasotracheal suction (30 minutes). The CG was subjected to the same protocol, except for nasotracheal suction. To assess the HRV, we used spectrum analysis, which decomposes the heart rate oscillations into frequency bands: low frequency (LF=0.04-0.15Hz), which corresponds mainly to sympathetic modulation; and high frequency (HF=0.15-1.2Hz), corresponding to vagal modulation. Results: Under baseline conditions, the BG showed higher values in LF oscillations, lower values in HF oscillations, and increased LF/ HF ratio when compared to the CG. After CPT, the values for HRV in the BG were similar to those observed in the CG during basal recording. Five minutes after nasotracheal suction, the BG showed a decrease in LF and HF oscillations; however, after 40 minutes, the values were similar to those observed after application of CPT. Conclusions: The CPT and nasotracheal suction, both used for airway clearance, promote improvement in autonomic modulation of HRV in children with acute bronchiolitis. [ABSTRACT FROM AUTHOR]

Stroke has been associated with cardiac autonomic impairment due to damage in central nervous system. Dysfunction in heart rate variability (HRV) may reflect dysfunction of the autonomic nervous system. Aerobic training has been used in the rehabilitation procedure of patients, due to improvement of aerobic function and other beneficial effects as increased recruitment of motor units, favoring the development of muscle fibers. The purpose of this study was to evaluate the cardiac autonomic modulation in patients with stroke before, during, and after an acute bout of aerobic exercise. The heart rate of 38 stroke patients was recorded using a heart rate (HR) monitor and the data were used to assess cardiac autonomic modulation through HRV analysis. The patients were in supine position and remained at resting condition (R) for 10 min before starting the experiment. Afterwards, they were submitted to walking exercise (E) on a treadmill until achieve 50-70 % of maximum heart rate. After 30 min of aerobic exercise, the subjects were advised to remain in supine position for additional 30 min in order to record the HR during the recovery (RC) period. The recordings were divided in three periods: RC1, immediately after the end of exercise bout, RC2, between 12 and 17 min of recovery, and RC3, at the final 5 min of recovery. A significant decrease was observed during exercise in the MeanRR index (577.3 ± 92 vs. 861.1 + 109), RRtri (5.1 ± 2 vs. 9.1 ± 3), high frequency component (11.2 ± 4 vs. 167 ± 135 ms) and SD1 (5.7 ± 2 vs. 16.9 ± 7 ms) compared to resting values. The SDNN index reduced during E (27.6 ± 19) and RC1 (29.9 ± 11), RC2 (27.9 ± 9) and RC3 (32.4 ± 13) compared to resting values (42.4 ± 19). The low frequency component increased during E (545 ± 82), but decreased during RC1 (166.3 ± 129), RC2 (206.9 ± 152), and RC3 (249.5 ± 236) compared to R levels (394.6 ± 315). These findings suggest that stroke patients showed a reduced HRV during and at least 30 min after exercise, due to an autonomic imbalance reflected by increased indexes that represent the sympathetic nervous system. [ABSTRACT FROM AUTHOR]

We investigated the effects of selective loads of periodization model (SLPM) on autonomic modulation of heart rate variability (HRV) and endogenous stress markers before and after a competition period in volleyball players ( N=32). The experimental protocol for the evaluation of HRV consisted of using spectral analysis of time series composed of the R-R intervals derived from electrocardiogram obtained in the supine position and during the tilt test. Stress marker levels were determined by quantifying the plasma concentration of endogenous catecholamines, cortisol and free testosterone. The results showed no changes between the levels of HRV before and after a competition period. In contrast, the quantification of the plasma concentration of endogenous stress markers revealed reductions in the levels of total catecholamines, noradrenaline and cortisol. These changes were accompanied by increases in the concentration of free testosterone and in the testosterone/cortisol ratio. In conclusion, our results demonstrate that the SLPM did not change the cardiac autonomic modulation of HRV, but promoted beneficial adaptations in athletes, including positive changes in the plasma concentration of the endogenous stress markers. The absence of changes in HRV indicates that there is no direct relationship between cardiac autonomic modulation and endogenous stress markers in the present study. [ABSTRACT FROM AUTHOR]

Background: It has long been speculated that mobile phones may interact with the cardiac devices and thereby cardiovascular system may be a potential target for the electromagnetic fields emitted by the mobile phones. Therefore, the present study was designed to test possible effects of radiofrequency waves emitted by digital mobile phones on cardiac autonomic modulation by short-time heart rate variability (HRV) analysis. Methods and Results: A total of 20 healthy young subjects were included to the study. All participants were rested in supine position at least for 15 minutes on a comfortable bed, and then time and frequency domain HRV parameters were recorded at baseline in supine position for 5 minutes. After completion of baseline records, by using a mobile GSM (Global System for Mobile Communication) phone, HRV parameters were recorded at turned off mode, at turned on mode, and at calling mode over 5 minutes periods for each stage. Conclusion: Neither time nor frequency domain HRV parameters altered significantly during off mode compare to their baseline values. Also, neither time nor frequency domain HRV parameters altered significantly during turned on and calling mode compared to their baseline values. Short-time exposure to electromagnetic fields emitted by mobile phone does not affect cardiac autonomic modulation in healthy subjects. (PACE 2011; 34:1511-1514) [ABSTRACT FROM AUTHOR]

Abstract: Background: There is little data available regarding the effects of male sex hormones on cardiac autonomic function. The aim of this study is to evaluate the association between hormones of male hypothalamo–pitiutary–gonadal axis and cardiac autonomic function by comparing heart rate variability (HRV) parameters of young male idiopathic hypogonadotropic hypogonadism patients with those of healthy controls. Methods: The study consisted of 22 male idiopathic hypogonadotropic hypogonadism patients (mean age 20.8±1.2years) and the same number of age-matched healthy male controls (mean age 21.0±1.5years). A 24-hour Holter monitoring was performed to assess the time and frequency-domain parameters. The HRV parameters of patients and control groups were compared, and possible associations between levels of tested hormones and HRV parameters were evaluated. Results: The standard deviation of all NN intervals (SDNN), standard deviation of the averages of NN intervals in all 5min segments (SDANN), power in low frequency range (LF, ms²) and power in high frequency range (HF, ms²) values of patients were significantly lower compared to those of controls (147.47±56.16 vs. 193.63±40.89; 138.31±57.64 vs. 190.15±43.94; 397.8±236.7 vs. 491.5±208.4; and 133.6±97.4 vs. 198.5±91.6 respectively; p <0.05 for all). Significant negative correlations were observed between serum FSH, LH and testosterone levels and most of the HRV parameters. Conclusions: Deficiency in the male hypothalamo–pituitary–gonadal axis seems to adversely affect cardiac autonomic modulation with increased sympathetic and decreased parasympathetic components of HRV. [Copyright &y& Elsevier]

The purposes of this study were to demonstrate the transition of heart rate variability (HRV) during trials in the field and to examine the relationship between peak frequency of high-frequency band (HF) and stride frequency. Ten healthy long-distance college female runners (age 19–21 years) performed a 3000 m realistic time trial. The time-series power spectrum analysis by maximum entropy method was used to evaluate cardiac autonomic nervous activity during the race. Cross-correlation coefficients were calculated to estimate the degree of linear co-ordination between the central peak frequency of HF and stride frequency. Just after starting, the decrease in HF (0.15–1.00 Hz) and a transient increase of low-frequency band (LF)/HF were found. After that, the HF remained at a low level and LF/HF decreased sharply. These findings suggested that the parasympathetic activity was suppressed and sympathetic activity increased just after starting, and the sympathetic activity reached the saturated level according to continuation of high-intensity exercise. In spite of the significant decrease of HRV during trials, peak frequency of HF could be differentiated clearly. The cross-correlation coefficient of peak frequency of HF and stride frequency was from 0.703 to 0.868. This finding indicated that exercise rhythm reflected HRV during high-intensity running in the field. [ABSTRACT FROM AUTHOR]