Cardiac Autonomic Activity Research Articles

The effects of a 6-hour ultra-endurance run on postexercise parasympathetic reactivation responses.

Alterations in cardiac autonomic control reflecting depressed parasympathetic activity have been previously reported after ultra-endurance events at rest and during dynamic tasks assessing cardiac autonomic responsiveness. This study investigated the impact of a 6-hour ultra-endurance run on parasympathetic reactivation indices, using an exercise-recovery transition approach. Nine trained runners (VO<inf>2max</inf> 67±12 mL/kg/min) completed a 6-hour run (EXP) whilst other six runners (VO<inf>2max</inf> 66±10 mL/kg/min) served as a control (CON). Before (PRE) and after the run/control period (POST) participants completed standard cardiac autonomic activity assessments. Postexercise parasympathetic reactivation was assessed by means of heart rate recovery (HRR) and vagal-related time-domain HRV indices. HR was increased at rest (P<0.001, ES=3.53), during exercise (P<0.05, ES=0.38) and recovery (all P<0.001, ES from 0.91 to 1.46) at POST in EXP and not in CON (all P>0.05). At POST vagal-related HRV indices were significantly decreased at rest (P<0.001, ES from -2.38 to -3.54) and during postexercise recovery (all P<0.001, ES from -0.97 to -1.58) only in EXP. HRR at 30 and 60 s were markedly reduced at POST in EXP both when expressed in bpm and normalized for the exercising HR (all P<0.001, ES from -1.21 to -1.74). A 6-hour run markedly impacted upon postexercise parasympathetic reactivation responses causing a decrease in HRR and HRV recovery indices. For the first time, this study attested blunted postexercise parasympathetic reactivation responses following an acute bout of ultra-endurance exercise.

Cardiac autonomic and cortisol stress responses to real operations in surgeons: relationship with individual psychobiological characteristics and experience

BackgroundSurgeons are exposed to high levels of intraoperative stress, which could compromise their psychological well-being in the long term. This study aimed at exploring the effects of real operations on the activity of stress response systems (i.e., cardiac autonomic function and hypothalamic–pituitary–adrenal axis) during and in the aftermath of surgery, and the moderating role of individual psychobiological characteristics and different levels of experience (senior vs expert surgeons).MethodsHeart rate, heart rate variability, and salivary cortisol measures (as indexes of cardiac autonomic and hypothalamic–pituitary–adrenal axis activity, respectively) were assessed during real operations and in the perioperative period in a sample of surgeons (n = 16). Surgeons’ psychometric characteristics were collected using questionnaires. Results. Real operations triggered both cardiac autonomic and cortisol stress responses which were independent from surgeons’ level of experience. Intraoperative stress responses did not affect cardiac autonomic activity during the following night but were associated with a blunted cortisol awakening response. Moreover, senior surgeons reported higher levels of negative affectivity and depressive symptoms than expert surgeons prior to the surgery. Lastly, the magnitude of heart rate responses to surgery positively correlated with scores on negative affectivity, depression, perceived stress, and trait anxiety scales.ConclusionThis exploratory study allows to put forward the hypotheses that in surgeons cardiac autonomic and cortisol stress responses to real operations (i) may be associated with specific individual psychological characteristics regardless of the level of experience, (ii) and may have a longer lasting impact on hypothalamic–pituitary–adrenal axis function with potential implications for surgeons’ physical and psychological well-being.

Evaluation of Cardiac Autonomic Activity During + Gz Stress in Military Pilots

Evaluation of Cardiac Autonomic Activity During + Gz Stress in Military Pilots

The effects of a 3-day mountain bike cycling race on the autonomic nervous system (ANS) and heart rate variability in amateur cyclists: a prospective quantitative research design

BackgroundThe acute and chronic adaptation of endurance athletes’ hearts shows that increased volume of endurance exercise might cause an acute reduction in cardiac function, causing a physiological cascade that leads to the release of cardiac biomarkers specific to cardiomyocyte stress. Heart rate variability (HRV) is a valuable tool used as a physiological measurement to evaluate the autonomic nervous system (ANS). It is frequently used to assess cardiac autonomic regulation, determining a patient’s risk for unfavorable events. This study set out to determine the changes in the ANS by participating in a 3-day mountain bike cycling race in amateur cyclists using HRV as an outcome measure.MethodsSixteen healthy participants (male and female) participating in a 3-day mountain bike cycling race underwent five-minute resting electrocardiography recordings in a supine position 2 days before the race (baseline testing). In addition, HRV measurements were recorded after each race day and 24 h post-race (recovery).ResultsTime-domain and frequency-domain measures showed significant changes from baseline HRV parameters after each race day (p ≤ 0.05). In addition, our data revealed that the mean heart rate and R–R variability intervals did not return to baseline values after 24 h of recovery. Thus, autonomic nervous system (ANS) alterations may be due to changes in cardiac sympatho-vagal balance.ConclusionsThe main strength of this study is using HRV as a measuring and screening tool to assess cardiac autonomic activity, whereby the state of the ANS before and after endurance races can be measured. Thus, physicians, athletes, and coaches can determine the stress of endurance races on the ANS and plan recovery strategies. The reasoning is that if the ANS is in a state of sub-optimal function, susceptible amateur athletes might be at risk for a cardiovascular event or maladaptation due to the endurance race.

Serum Vitamin D Levels in Children and Adolescents with Vasovagal Syncope, Syncope Due to Orthostatic Hypotension, and Cardiac Syncope.

The study aimed to compare vitamin D levels between children and adolescents with vasovagal syncope, syncope due to orthostatic hypotension, cardiac syncope, and healthy individuals and to investigate the correlations of 25(OH)D with main clinical parameters of syncope. This study involved 83 children aged 8-17 years with syncope: 40 with vasovagal syncope, 24 with syncope due to orthostatic hypotension, and 19 with cardiac syncope. There were 24 healthy volunteers in the control group. Data concerning active standing test, electrocardiography, echocardiography, electroencephalography, and 24-hour Holter monitoring findings were collected. Serum vitamin D was evaluated by an enzyme-linked immunoassay technique test. The mean levels of serum 25(OH)D were decreased in children with vasovagal syncope (18.8 ± 5.9 ng/mL), syncope due to orthostatic hypotension (19.9 ± 6.7 ng/mL), and cardiac syncope (20.6 ± 7.3 ng/mL) in comparing with the control group (30.9 ± 5.9 ng/mL; P < .001). In patients with syncope due to orthostatic hypotension, vitamin D deficiency was associated with a reduction in systolic blood pressure (r = 0.43) and diastolic blood pressure (r = 0.38) within the first minute, lower systolic blood pressure (r = 0.44) within the third minute of active orthostasis (P < .05). There were significant correlations of vitamin D deficiency with parameters of cardiac autonomic activity pNN50 (r = 0.49), total power (r = 0.39), and low frequency index (r = 0.35) in children with cardiac syncope (P < .05), while heart rate variability was not affected in patients with vasovagal syncope and syncope due to orthostatic hypotension (P > .05). Children and adolescents with vasovagal syncope, syncope due to orthostatic hypotension, as well as cardiac syncope had higher frequency of vitamin D deficiency than healthy pediatric controls. This provides a new approach to syncope management in pediatric population, requiring further studies.

Implicit Measures of Extreme Psychological Distress in Young Healthy Adults: Cardiac Autonomic Activity and Attentional Bias

Implicit Measures of Extreme Psychological Distress in Young Healthy Adults: Cardiac Autonomic Activity and Attentional Bias

Physiological Effects of Using Citrus Mint Flavored Mouthwash

This study aimed to investigate the effect of flavored mouthwash on peripheral and cardiac autonomic nervous system activity. In a within-subject experimental design, 10 male and 10 female healthy adults went through two types of mouthwashes, one was with citrus mint flavor and another was with spice mint flavor, right after performing a 20-minute calculation task given as a cognitive stressor. Along with subjective evaluation, skin conductance and electrocardiogram was recorded throughout the experiment. Although there was no difference in the subjective stress levels between the two conditions, the level of skin conductance decreased more remarkably and significantly during the recovery period when the participants used citrus mint mouthwash. The findings suggest that a particular flavored mouthwash may provide physiological effect on user regardless of its subjective sensation and the citrus mint type mouthwash might be better suited for use in need of a relaxation.

The Association of Depression With QT Duration: A Comparison Between Individuals Younger or Older Than 65 Years.

The electrocardiogram-derived corrected QT (QTc) interval is an indicator of cardiac autonomic activity that has been proposed as a biological measure to investigate the interplay between depression and cardiovascular diseases. This study assesses whether depression is associated with a longer QTc interval across age groups. Assessment of depressive symptoms was performed in 1637 participants of the cross-sectional Corinthia study with the Zung Self-Rating Depression Scale in those younger than 65 years (group 1) and with the Geriatric Depression Scale in elderly individuals (≥65 years, group 2). The QT interval was obtained from electrocardiogram recordings and corrected for heart rate (QTc). Individuals in group 1 with depression were predominantly women and had a higher prevalence of coronary artery disease and diabetes mellitus. Group 1 individuals with depression had longer QTc duration (no depression versus depression, 389.3 [27.0] versus 401.1 [32.9] milliseconds; p < .001) and percentage of abnormal QTc (no depression versus depression, 2.0% versus 10.8%; p = .001) compared with those without depression. Elderly individuals (group 2) had similar values of QTc and percentage of abnormal QTc irrespective of depression status. Even after adjustment for known QT-prolonging factors, the presence of depression in younger individuals was associated with an increased QTc by 11.1 milliseconds and with an approximately 10.6-fold higher prevalence of abnormal QTc duration. Depression was associated with a longer QTc interval especially in individuals younger than 65 years. These findings may indicate an interrelationship between depression and autonomic dysregulation as potential risk factors for cardiovascular disease and sudden cardiac death.

Unhealthy lifestyle impacts on biological systems involved in stress response: hypothalamic-pituitary-adrenal axis, inflammation and autonomous nervous system.

An unhealthy lifestyle has a critical role in the pathogenesis and course of several chronic disorders. It has been hypothesized that lifestyle may also impact biological systems involved in stress response. A global index of unhealthy lifestyle was calculated based on the cumulative presence of five self-reported lifestyle habits (smoking, excessive alcohol use, drug use, low physical activity and short sleep) in 2783 participants (18-65 years) from the Netherlands Study of Depression and Anxiety. The functioning of biological stress systems was based on multiple physiological measures of cortisol, inflammatory cytokines and autonomic cardiac activity. The unhealthy lifestyle index was associated with hyperactivity of hypothalamus-pituitary-adrenal axis and increased inflammation, indicating that with increasing unhealthy habits, the level of biological stress increases. No association with the autonomic nervous system activity was observed; however, the use of drugs increased parasympathetic cardiac activity and significantly impacted on ANS. Results were not impacted by a recent episode of depression or anxiety disorder. An unhealthy lifestyle may unfavorably impact on biological systems involved in stress response, which may underlie progression of several psychiatric as well as somatic chronic disorders.

Changes in heart rate variability of healthy subjects shortly exposed to printing shop particles and the effect of air purifier intervention

Particulate matter (PM) released by printers may cause airway inflammation and cardiac electrophysiological changes. We conducted a two-stage crossover study to examine the association between short-term exposure to printing shop particles (PSPs) and the heart rate variability (HRV) among healthy volunteers, as well as to evaluate the effect of air purifier intervention. The on-site assessments of PSPs and individual HRV parameters of the volunteers were used to analyze the influence of size-fractionated PSPs and air purifier intervention on HRV at different lag times after PSPs exposure (0 min, 5 min, 15 min, and 30 min) by using the linear mixed-effects models. We observed that changes in 6 HRV parameters were associated with particle mass concentration (PMC) of PSPs, and changes in 8 HRV parameters were associated with particle number concentration (PNC) of PSPs. The sensitive HRV parameters were the square root of the mean of the sum of the squares of differences between adjacent NN intervals (rMSSD), NN50 count divided by the total number of all NN intervals (pNN50), normalized high frequency power (nHF), very high frequency power (VHF), normalized low frequency power (nLF), and the ratio of low frequency power to high frequency power (LF/HF). Most HRV parameters exhibited the strongest effect associated with PMC and PNC at a lag time of 30 min. The air purifier intervention markedly reduced the PNC and PMC of size-fractionated PSPs, enhanced 5 HRV parameters, and decreased the nLF and LF/HF. Our study suggests that short-term exposure to PSPs can affect HRV parameters, reflecting changes in cardiac autonomic nervous activity, and the use of an air purifier can reduce the concentration of PSPs and improve the autonomic nervous system activity of the exposed individuals.

Alterations in heart rate variability before and after percutaneous coronary intervention in patients with ischaemic heart disease

Objectives: Heart rate variability (HRV) is the beat-to-beat variation of heart rate and an important non-invasive tool to study the cardiac autonomic nervous system activity. Ischaemic heart disease (IHD) patients are often considered to have a state of sympathetic predominance. Elimination of myocardial ischaemia with percutaneous coronary intervention (PCI) could restore autonomic balance. Hence, this study aimed to evaluate HRV measures, after successful revascularisation among IHD patients. Materials and Methods: A total of 145 male IHD patients planned for coronary angiography were recruited. Fifteen minutes of electrocardiogram recording was done. Short-term HRV analyses of all the patients were acquired and time-domain indices (standard deviation of normal-to-normal intervals [SDNN], root-mean-squared differences of successive R-R intervals [rMSSD]) and frequency-domain indices (low-frequency [LF] power, high-frequency [HF] power and total power [TP]) were analysed. Before and after PCI, all measurements were made. Results: This study included 145 male IHD patients with the mean age of 54.57 ± 10.81 years. There was a significant decrease in SDNN, rMSSD, LF, HF and TP whereas increase in LF/HF ratio following revascularisation. These changes in measures of neurocardiac regulation correlated with risk factors and medication on regression analysis. Conclusion: Increase in LF/HF ratio with the decrease in SDNN, rMSSD, LF, HF and TP in patients with IHD who underwent coronary intervention infers changed cardiac autonomic balance with this surgical procedure. These measures could be potentially used as prognostic measures in the future studies.

Cardiac autonomic modulation with donepezil attenuates pyroptosis and mitochondrial dysfunction, leading to improved left ventricular function in trastuzumab-induced cardiotoxicity in rats

Abstract Background Trastuzumab (Trz)-induced cardiotoxicity (TIC) is one of the most common cardiovascular complications of targeted anticancer agents. Cardiac inflammation, cardiac mitochondrial dysfunction, oxidative stress, and cardiac autonomic dysfunction have been identified as potential mechanisms underlying the adverse effects of TIC. Although cardiac inflammation is one of the key mechanisms triggering “pyroptosis”, i.e. a new inflammatory form of programmed cell death, the association between TIC and pyroptosis is still largely unknown. Moreover, the modulation of cardiac autonomic activity using an acetylcholinesterase inhibitor (AChE) has been shown to exert cardioprotection in various heart diseases. However, the role of donepezil (DPZ), an AChE, in treating TIC has never been investigated. Purpose We evaluated the cardioprotective effects of DPZ on left ventricular (LV) function, cardiac mitochondrial function, and pyroptosis in rats with TIC. We hypothesised that DPZ reduces mitochondrial dysfunction and pyroptosis, leading to a reduction of LV dysfunction in TIC rats. Methods Fifteen male Wistar rats were randomly divided into the control group (n=5, 0.9% normal saline solution, ip) and the Trz group (n=10, 4 mg/kg/day for 7 days, ip). Trz-treated rats were subdivided into the vehicle group (n=5, drinking water, po) and the DPZ group (n=5, 5 mg/kg/day for 7 days, po). At the end of the experiment, echocardiography was performed, and the heart was removed to determine the cardiac mitochondrial function and pyroptosis. Results Compared with the control group, %LV ejection fraction (%LVEF) was significantly decreased in the Trz group (Fig. 1A). Trz treatment also markedly increased cardiac mitochondrial reactive oxygen species (ROS) production and mitochondrial depolarisation, as indicated by a lower red/green fluorescence intensity ratio (Fig. 1B and C, respectively). Furthermore, Trz induced pyroptosis by increasing NLR family pyrin domain containing 3 (NLRP3) expression and cleaved Gasdermin D/Gasdermin D ratio, compared to the control group (Fig, 1D–F). Notably, DPZ co-treatment potentially reduced mitochondrial ROS production, mitochondrial depolarisation, and pyroptosis (NLRP3 and cleaved Gasdermin D/Gasdermin D ratio), leading to improved %LVEF (Figure 1). Conclusion DPZ alleviated cardiac dysfunction in TIC rats by improving mitochondrial function and reducing pyroptosis. These findings suggested that DZP could be a novel effective pharmacological intervention against TIC. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): 1. The National Science and Technology Development Agency Thailand2. The Thailand Research Fund (RGJ)

Effects of Chronic Mild Stress on Cardiac Autonomic Activity, Cardiac Structure and Renin-Angiotensin-Aldosterone System in Male Rats.

Simple SummaryStress can cause heart disease by changing cardiac structure and/or function as assessed by heart rate variability; however, this may or may not happen when exposed to daily stress. Therefore, this study was conducted to investigate alterations in cardiac structure and cardiac control through autonomic activity, and in the renin–angiotensin–aldosterone system in male rats after exposure to 4-week chronic mild stress as an animal model for daily stress exposure in humans. The results showed that chronic mild stress increased both sympathetic and parasympathetic autonomic activities without affecting their balance. The renin–angiotensin–aldosterone system, which was partly responsible for changes in cardiac structure, was also affected. These data suggest that cardiac autonomic control and cardiac structure were affected by 4-week mild stress; however, this effect was probably in an adaptable period as the sympathetic and parasympathetic activities were in balance.Stress is associated with cardiovascular disease. One accepted mechanism is autonomic imbalance. In this study, we investigated the effects of chronic mild stress (CMS) on cardiac autonomic control, cardiac structure and renin–angiotensin–aldosterone system (RAAS) activity in adult male Sprague Dawley rats. The CMS model provides a more realistic simulation of daily stress. The animals were divided into control and CMS, and were exposed to 4-week mild stressors. The electrocardiogram recording, sucrose intake and parameters related to stress, cardiac alterations and RAAS were determined. The results showed that CMS had lower body weight and higher sucrose intake. The heart rate variability (HRV) revealed that CMS increased autonomic activity without affecting its balance. The increased RAAS activity with upregulated angiotensin type 1 receptor mRNA expression was shown in CMS. The increased sympathetic activity or RAAS was correlated with stress. Moreover, the altered cardiac structure (i.e., heart weight and cardiomyocyte cross-sectional area) were correlated with stress-, sympathetic- and RAAS-related parameters. These indicated that CMS-induced cardiac hypertrophy was the result of both sympathetic and RAAS activation. Therefore, it could be concluded that 4-week CMS in male rats induced negative emotion as shown by increased sucrose intake, and increased cardiac autonomic and RAAS activities, which may be responsible for mild cardiac hypertrophy. The cardiac hypertrophy herein was possibly in an adaptive, not pathological, stage, and the cardiac autonomic function was preserved as the autonomic activities were in balance.

Effect of Algorithmic Music Listening on Cardiac Autonomic Nervous System Activity: An Exploratory, Randomized Crossover Study.

It is proven that music listening can have a therapeutic impact in many clinical fields. However, to assume a curative value, musical stimuli should have a therapeutic logic. This study aimed at assessing short-term effects of algorithmic music on cardiac autonomic nervous system activity. Twenty-two healthy subjects underwent a crossover study including random listening to relaxing and activating algorithmic music. Electrocardiogram (ECG) and non-invasive arterial blood pressure were continuously recorded and were later analyzed to measure Heart Rate (HR) mean, HR variability and baroreflex sensitivity (BRS). Statistical analysis was performed using a general linear model, testing for carryover, period and treatment effects. Relaxing tracks decreased HR and increased root mean square of successive squared differences of normal-to-normal (NN) intervals, proportion of interval differences of successive NN intervals greater than 50 ms, low-frequency (LF) and high-frequency (HF) power and BRS. Activating tracks caused almost no change or an opposite effect in the same variables. The difference between the effects of the two stimuli was statistically significant in all these variables. No difference was found in the standard deviation of normal-to-normal RR intervals, LFpower in normalized units and LFpower/HFpower variables. The study suggests that algorithmic relaxing music increases cardiac vagal modulation and tone. These results open interesting perspectives in various clinical areas.

Autonomic Nervous System in Preterm Very Low Birth Weight Neonates with Intraventricular Hemorrhage.

Heart rate variability (HRV) indicates cardiac autonomic nerve activity and is influenced by brain damage during the neonatal period. We aimed to determine whether a correlation exists between the HRV of extremely preterm neonates and neurodevelopmental test scores. Electrocardiogram data of neonates were assessed and HRV patterns in extremely preterm neonates with severe intraventricular hemorrhage (IVH; n = 6) and those with no/mild IVH (n = 28) were compared. We analyzed the relationship between HRV and neurodevelopmental outcomes at 18 months (n = 21) and 3 years (n = 23) in extremely preterm neonates. HRV was significantly associated with IVH severity in extremely preterm neonates (p < 0.05). Neonates with severe IVH exhibited increased HR and decreased mean R-to-R interval (NN) compared with neonates with no/mild IVH. HRV parameters significantly decreased in the severe IVH group, but not in the no/mild IVH group, suggesting that both sympathetic and parasympathetic activities decreased in neonates with severe IVH. Additionally, decreased HR and increased NN were significantly related to impaired neurodevelopmental outcomes in the no/mild IVH group at corrected ages of 18 months and 3 years, respectively (all p < 0.05). HRV was significantly associated with IVH severity and neurodevelopmental outcome in extremely preterm neonates. HRV can distinguish extremely preterm neonates who subsequently had severe IVH from those who had no/low-grade IVH. HRV may identify extremely preterm neonates needing adjuvant neuroprotective interventions. These findings warrant further investigation in a larger population of extremely preterm neonates. · HRV was associated with IVH severity.. · HRV can predict subsequent severe IVH in extremely preterm neonates.. · HRV are predictive of neurodevelopmental outcomes in extremely premature neonates with low-grade IVH..

Slow yoga breathing improves mental load in working memory performance and cardiac activity among yoga practitioners.

This study investigated the immediate effect of slow yoga breathing (SYB) at 6 breaths per minute (bpm) simultaneously on working memory performance and heart rate variability (HRV) in yoga practitioners. A total of 40 healthy male volunteers performed a working memory task, ‘n-back’, consisting of three levels of difficulty, 0-back, 1-back, and 2-back, separately, before and after three SYB sessions on different days. The SYB sessions included alternate nostril breathing (ANB), right nostril breathing (RNB), and breath awareness (BAW). Repeated measures analysis of variance showed a significant reduction in reaction time (ms) in 2-back condition immediately after ANB (−8%), RNB (−8%) and BAW (−5%) practices. Similarly, the accuracy was improved in the 0-back condition after RNB (4%), and in the 2-back condition after ANB (6%) and RNB (6%) practices. These results suggest that SYB practice enhances cognitive abilities (8–9%) related to memory load and improves the functioning of cardiac autonomic activity, which is required for the successful completion of mental tasks.Trial registered in the Clinical Trials Registry of India (CTRI/2018/01/011132).

Cardiac autonomic activity, endothelial function and physical fitness in type 2 diabetic patients

Objective: To investigate the association between cardiac autonomic activity, endothelial function, and physical fitness in patients with type 2 diabetes mellitus (T2DM). Methods: Twenty-seven patients with T2DM were studied, with a mean age of 57 ± 9 years and a mean disease duration of 7.4 ± 5 years. The assessment of physical fitness was performed using the Shuttle Walking Test (SWT), cardiac autonomic modulation by heart rate variability (HRV), and endothelial function was assessed by flow-mediated dilation (FMD) of the brachial artery through ultrasound imaging. Results: The main finding of this study was that some HRV indices (SDNN, RMSSD, and HF) were significantly correlated with endothelial function in individuals with T2DM, with R values between 0.51 and 0.57 (p &lt; 0, 05), for all relationships. Additionally, an association was found between the distance covered in the SWT and the basal diameter of the brachial artery (R = 0.59; p = 0.01). Conclusion: Our data demonstrate that some HRV indices are associated with DMF, indicating an interaction between these two systems. Furthermore, our findings suggest a correlation between physical fitness and endothelial function in individuals with T2DM.

Effects Of Static Core Training On Hemodynamics, Cardiac Autonomic Activity, And Arterial-cardiac Baroreflex Sensitivity During Head Up Tilt

Effects Of Static Core Training On Hemodynamics, Cardiac Autonomic Activity, And Arterial-cardiac Baroreflex Sensitivity During Head Up Tilt

Effects of a Combined Intradialytic Exercise Training Program and Music on Cardiac Autonomic Nervous System Activity in Hemodialysis Patients.

This study aimed to examine the effect of an intradialytic exercise program in combination with music on heart rate variability (HRV) indices and functional capacity in patients on maintenance hemodialysis (HD). Methods: Forty HD patients were randomized to four training groups for six months: the combined music and exercise group (Group A), the exercise group (Group B), the music group (Group C), and the control group (Group D). At baseline and after 6 months, all participants underwent both short- (for 30 min) and long- (for 24 h) term measurements of HRV and functional capacity assessment with a 6 min walking test (6MWT). Patients of groups A and C listened to preferred music. Results: Long-term HRV analysis showed that standard deviation of all normal-to-normal RR intervals (SDNN) and the square root of the mean squared differences of successive RR intervals (rMSSD) were significantly higher at the end of the study in groups A (by 13.2% and 47.3%), B (by 15.1% and 50%), and C (by 9.0% and 30.1%), compared to group D (p < 0.05). Values of rMSSD and percentage of RR intervals differing by more than 50 ms from the preceding RR interval (pNN50) were elevated in groups A (by 35.6% and 142.9%), B (by 36.1% and 75%), and C (by 15.2% and 28.6%), compared to baseline measurements (p < 0.05). Also, pNN50 was increased in group A compared to groups B (by 21.4%), C (by 88.9%), and D (by 142.9%) (p < 0.05). Similar results were noted by short-term HRV analysis. Functional capacity was improved at the end of the 6-month study in groups A (by 20.3% and 25.7%) and B (by 15.8% and 21.1%) compared to groups C and D (p < 0.05). Conclusions: Intradialytic exercise combined with music-listening can improve the functional capacity and cardiac autonomic nervous system activity in hemodialysis patients.

Cardiac autonomic nervous activity in patients with transposition of the great arteries after arterial switch operation

BackgroundA chronic imbalance of the autonomic nervous system(ANS) may contribute to long term complications in different congenital heart diseases. The purpose of this study was to determine whether the ANS plays a role in the long-term outcome of patients with Transposition of great arteries(TGA) after arterial switch operation(ASO) as its contribution is as yet not clear. MethodsThe ANS activity was evaluated non-invasively in 26 TGA patients and 52 age-appropriate healthy subjects combining impedance cardiography and electrocardiography. Heart rate, pre-ejection period(sympathetic activity parameter) and respiratory sinus arrhythmia and the root of the mean square of successive normal-to-normal interval differences(parasympathetic activity parameter) were measured during 5 different daily activities(sleep, sitting, active sitting, light and moderate/vigorous physical activity). Whether the ANS activity was related to ventricular function, exercise test performance or clinical outcome in the patient group was also analyzed. ResultsCompared to healthy subjects: heart rate was significantly lower in TGA patients at rest and during quiet and active sitting; sympathetic activity was significantly reduced in patients during physical activity; and the parasympathetic activity was higher in TGA patients while quiet and active sitting. In the patient group a significant positive correlation between 4-chamber longitudinal strain and parasympathetic activity during 3 different daily activities was found. ConclusionsThe sympathetic nervous system response to physical activity is reduced in TGA patients after ASO. Additionally, we observed a positive correlation between better left ventricular function and higher parasympathetic activity that could be in line with the known protective effect of a higher vagal activity.