Differences Of Successive NN Intervals Research Articles

The Influence of Autonomic Nervous System during Resting State on the Peripheral Pulse Wave Velocity in Young Adult Males

Abstract Background: The association between the activity of autonomic nervous systems (ANS) and pulse wave velocity (PWV) was commonly deduced after adjusting for confounding factors. The relationship between the ANS and PWV was either maintained, but attenuated, or no longer statistically connected after controlling for confounding variables. Research in young healthy individuals showed that the ANS does not control aortic stiffness (indexed by PWV) in a pressure-independent manner. Therefore, the role of the ANS in controlling PWV is debatable. Objectives: The objective of this study was to examine the possibility that ANS directly affects PWV independent of blood pressure (BP) and heart rate (HR). Subjects and Methods: Thirty-four healthy male volunteers (19 years old) were recruited. Stable brachial systolic BP (SBP)/diastolic BP (DBP) and HR were measured in semi-supine position after a 15-min rest. During the last 5 min, fingertip digital pulse wave (DPW) and lead II electrocardiogram (ECG) signals were recorded. The pulse transit time, and consequently PWV, was calculated by measuring the duration between the ECG R wave climax and a reference point on the DPW in the same cardiac cycle. The ANS activity was assessed by calculating the HR variability (HRV) indices obtained from the ECG record of 5-min R-R intervals (RRIs). Results: HRV indices low-frequency (LF)/high-frequency (HF) (LF band power measured in the 0.04–0.15 Hz)/the HF band power measured in the 0.15–0.4 Hz band) and SD2/SD1 ratios (SD1 and SD2 represent the dispersion along the minor and major axis of the fitted ellipse of the Poincaré plot) (sympathovagal balance) were significantly and positively correlated with PWV. In addition, the standard deviation of RRI, or normal-to-normal “NN” (SDNN) interval, after excluding ectopic beats, the square root of the mean squared differences of successive NN intervals (RMSSD) were significantly and negatively correlated with the PWV. No correlation was obtained between PWV and HR, SBP, or DBP. Conclusion: Peripheral PWV during rest or inactivity is affected directly by the sympathovagal balance independent of BP.

Time course efficiency of MICE and HIIE on inhibitory control and HRV in adolescents with obesity and different cardiorespiratory fitness.

Adolescent obesity is associated with impaired inhibitory control. Acute exercise can improve executive function. However, due to the influence of exercise intensity, cognitive test timing, and cardiorespiratory fitness (CF) level, the most effective exercise program remains controversial. The current study investigated the time-course effects of moderate-intensity continuous exercise (MICE) and high-intensity interval exercise (HIIE) on inhibitory control (Stroop) and task-related heart rate variability (HRV) in adolescents with different CF. A mixed experimental design of 2 CF levels (high CF, HCF; low CF, LCF) × 3 exercise methods (MICE, HIIE, CON) × 3 test timing (pre, post-0, post-20) was adopted. Heart rate variability (HRV) and Stroop task tests were conducted before exercise (pre), immediately after exercise (post-0), and 20 min after exercise (post-20). Individuals with HCF exhibited a positive decrease in Stroop response time immediately and 20 min after MICE and HIIE, compared to pretest response times (RT). Conversely, individuals with LCF showed a slight increase in Stroop task (RT) only immediately after HIIE. All individuals had a slight increase in ACC after MICE and HIIE compared to before exercise. In addition, compared with the control group, the time-domain index (the square root of the mean squared differences of successive NN intervals, RMSSD) of HRV was significantly decreased, the frequency-domain index (the absolute power of the Low-Frequency band/the absolute power of the High-Frequency band ratio, LF/HF) was significantly increased after MICE and HIIE, and the effect of HIIE on RMSSD and LF/HF was significantly greater than that of MICE. The current study found that the acute effects of MICE and HIIE on inhibitory control in obese adolescents were influenced by the interaction of cognitive test timing and cardiorespiratory fitness. Individuals with high cardiorespiratory fitness performed better on the Stroop task than individuals with low cardiorespiratory fitness. The inhibitory control of HIIE in high-cardiorespiratory obese adolescents produced positive effects similar to those in MICE but more lasting, suggesting that HIIE is more beneficial for high-cardiorespiratory obese adolescents. MICE promoted inhibitory control in obese adolescents with low cardiorespiratory fitness, but HIIE impaired inhibitory control in obese adolescents with low cardiorespiratory fitness immediately after exercise, suggesting that low cardiopulmonary fitness obese adolescents may be suitable for MICE rather than HIIE exercise intervention. The shift from balanced HRV to sympathetic dominance after acute exercise reflects increased arousal levels and may be one of the underlying mechanisms by which acute exercise brings benefits to executive function.

Role of Meditation in Ameliorating Examination Stress Induced Changes in Cardiovascular and Autonomic Functions.

Examination stress is a very well-known model of psychological stress in students. It induces changes in systolic (SBP) and diastolic blood pressure (DBP), along with changes in heart rate variability (HRV) and baroreflex sensitivity (BRS), due to autonomic perturbations. To find out if Raj Yoga meditation (RYM) practice affects autonomic and cardiovascular function in healthy young subjects during periods of examination stress. Our primary objective was to evaluate the effect of one month of supervised RYM practice on ameliorating examination-induced changes in cardiovascular and autonomic function. The secondary objective was to measure the stress levels of medical students before and after RYM. Pre-training measurements of SBP, DBP, HRV, and BRS were done, and the Medical Student Stressor Questionnaire (MSSQ) was administered to 80 participants one month before examinations. They were then trained in RYM. Post-training assessment of the same parameters was done after examinations and also after two months. In our study, RYM training decreased DBP (p = 0.01) but not SBP. BRS showed a trend towards an increase after RYM practice, but it was not statistically significant (p = 0.44). The standard deviation of the NN interval (SDNN) (p = 0.03), low-frequency (LF) nu (0.003), and high-frequency (HF) nu (0.04) showed a statistically significant change. Average RR, median RR, average rate, square root of the mean squared differences of successive NN intervals (RMSSD), pRR, total power, LF (µs2), and LF/HF ratio were not statistically significantly different between the three groups. There was a statistically significant decline in MSSQ scores for MSSQ I (p = 0.04), MSSQ II (p = 0.04), and MSSQ IV (p = 0.03). Short-term practice of supervised RYM during stressful periods is protective for the cardiovascular and autonomic systems and decreases stress in medical students.

Heart rate variability as a predictor of mechanical ventilation weaning outcomes

BackgroundDelays in the mechanical ventilation (MV) weaning process increase mortality. The spontaneous breathing test is the gold standard to assess weaning and extubation success, although it has approximately 85% accuracy. Studies have demonstrated a correlation between decreased heart rate variability (HRV) and weaning failure. ObjectivesTo assess the usefulness of HRV as a predictor of MV weaning outcomes. MethodsCross-sectional analytical study in adults of both sexes on MV in intensive care unit (ICU) stay. Patients were divided into weaning success and failure groups. Clinical data were collected, and HRV records were obtained with a heart rate monitor. ResultsThe study included 68 individuals – 91.1% in the weaning success group and 8.9% in the failure group. All HRV indices analyzed in both groups were lower than the reference values. No statistical difference was found in the mean RR interval (RRi), the standard deviation of the NN interval (SDNN), and the square root of the mean squared differences of successive NN intervals (RMSSD) between the groups. The weaning failure group had a significant increase in LF (41 vs. 69.4) and LF/HF ratio (0.685 vs. 2.6) and a significant decrease in HF (58.85 vs. 30.2). ConclusionsHRV measure with spectral analysis can be a good predictor of MV weaning failure. Integrating this assessment tool in ICU to predict weaning outcomes could provide more precise prognoses and more adequate assistance quality.

Arrhythmia and Heart Rate Variability during Long Interdialytic Periods in Patients on Maintenance Hemodialysis: Prospective Observational Cohort Study.

Sudden cardiac death among hemodialysis patients is related to the hemodialysis schedule. Mortality is highest within 12 h before and after the first hemodialysis sessions of a week. We investigated the association of arrhythmia occurrence and heart rate variability (HRV) using an electrocardiogram (ECG) monitoring patch during the long interdialytic interval in hemodialysis patients. This was a prospective observational study with 55 participants on maintenance hemodialysis for at least six months. A patch-type ECG monitoring device was applied to record arrhythmia events and HRV during 72 h of a long interdialytic period. Forty-nine participants with sufficient ECG data out of 55 participants were suitable for the analysis. The incidence of supraventricular tachycardia and ventricular tachycardia did not significantly change over time. The square root of the mean squared differences of successive NN intervals (RMSSD), the proportion of adjacent NN intervals differing by >50 ms (pNN50), and high-frequency (HF) increased during the long interdialytic interval. The gap in RMSSD, pNN50, HF, and the low-frequency/high-frequency (LF/HF) ratio between patients with and without significant arrhythmias increased significantly over time during the long interdialytic interval. The daily changes in RMSSD, pNN50, HF, and the LF/HF ratio were more prominent in patients without significant arrhythmias than in those with significant arrhythmias. The electrolyte fluctuation between post-hemodialysis and subsequent pre-hemodialysis was not considered in this study. The study results suggest that the decreased autonomic response during interdialytic periods in dialysis patients is associated with poor cardiac arrhythmia events.

Impact of COVID-19 Vaccination on Heart Rate Variability: A Systematic Review.

Establishing and disseminating evidence-based safety information could potentially facilitate beneficial choices in coronavirus disease (COVID-19) vaccinations. This systematic review investigated the potential impact of COVID-19 vaccinations on human heart rate variability (HRV) parameters through comprehensive searches of four electronic medical databases. Five observational studies reporting HRV parameters of individuals vaccinated against COVID-19 and published up to 29 July 2022 were included in this review. Among them, four studies reported the square root of the mean squared differences of successive NN intervals (RMSSD) as their outcome, and the remaining study reported an HRV-based stress indicator. These studies reported short-term changes and rapid recovery in HRV parameters within up to 3 days after COVID-19 vaccination. Some studies showed that the impact of COVID-19 vaccinations on RMSSD was greater in women than men, and in the younger group than in the older group. The methodological quality of the included studies was not optimal; the review revealed short-term changes in HRV parameters, particularly RMSSD, following COVID-19 vaccination. However, as the included studies did not report important parameters besides RMSSD, the limitation exists that the postvaccination long-term HRV stability was not reported.

Abstract 15665: Pod-Based Electronic Cigarette Use Alters Measures of Heart Rate Variability

Background: Previous studies demonstrate changes in autonomic function with combustible and earlier generation electronic cigarette (ecig) use. We sought to explore the effects of nicotine salt containing pod-based ecigs on autonomic regulation in young adult regular users by analyzing indices of heart rate variability (HRV). Methods: We enrolled healthy adults (18-45 yo) who were self-reported tobacco nonusers, pod-based ecig users, or combustible cigarette users. Participants were asked to refrain from tobacco product use at least 6 h before the study visit. Indices of HRV: standard deviation of the NN intervals (SDNN) and the root mean square differences of successive NN intervals (RMSSD, measure of parasympathetic function) were measured by Sphygmacor before and 10 minutes after structured use of participants’ own product. Measurements of urinary levels of cotinine, a nicotine metabolite, and 3HPMA, an acrolein metabolite, were made 1 h after product use. Results: In 133 subjects (age 26±5, 49% women), baseline HRV measures were comparable among tobacco non-users (N=39), pod-based ecig users (N=64), and combustible cigarette users (N=30). Analyses adjusted for age and sex demonstrated that acute pod-based ecig use reduced SDNN compared with non-use (-5.9±2.6ms vs 6.5±3.2ms, P=0.004) and similar to the effect of combustible cigarette use (-10.2±3.8ms, P=0.37). Moreover, acute pod-based ecig use reduced RMSSD compared with non-use (-5.6±3.3ms vs 5.4±4.1ms, P=0.04) and similar to the effect of combustible cigarette use (-10.9±4.9ms, P=0.38). Urinary cotinine, reflective of nicotine exposure, was associated with decreases in SDNN and RMSSD (r=-0.33, P=0.001; r=-0.29,P=0.003, respectively) whereas 3HPMA associated with SDNN and showed a trend toward association with RMSSD (r=-0.27, P=0.006; r=-0.18, P=0.06, respectively). Conclusion: Our data demonstrate an association between acute use of pod-based ecigs and altered cardiac autonomic function in association with the level of nicotine and acrolein exposure.

Association between postoperative delirium and heart rate variability in the intensive care unit and readmissions and mortality in elderly patients with cardiovascular surgery.

This study aimed to investigate the relationship between heart rate variability (HRV), a parameter of the autonomic nervous system activity (ANSA), and postoperative delirium and postoperative events. This retrospective cohort study included elderly patients aged 65years or older who were admitted to the intensive care unit (ICU) after cardiovascular surgery. ANSA was measured using HRV parameters for 1h at daytime and 1h at night-time before ICU discharge. The primary endpoint was the effect of HRV parameters and delirium on mortality and readmission rates within 1year after discharge, and the secondary endpoint was the association between HRV parameters and delirium. Cox proportional hazards models were used to examine the association between HRV parameters and postoperative events by adjusting for delirium and pre and postoperative information. A total of 71 patients, 39 without delirium and 32 with delirium, met the inclusion criteria. The incidence of death and readmission within 1year was significantly higher in the delirium group and in the group with higher daytime HF (high frequency power) and r-MSSD (square root of the squared mean of the difference of successive NN intervals), parameters of the parasympathetic nervous system activity (PNSA), than that in other groups. Furthermore, the delirium group had significantly higher HF and r-MSSD than the nondelirium group. Even after adjusting for confounding factors in the multivariate analysis, a trend of higher daytime HF and r-MSSD was observed, indicating a significant effect on the occurrence of combined events within 1year of discharge. ICU delirium has been associated with higher daytime HF and r-MSSD, parameters of PNSA. ICU delirium was a prognostic factor, and increased daytime PNSA may worsen the prognosis of elderly patients after cardiovascular surgery.

Heart rate fragmentation as a marker of altered global autonomic nervous system activity: a novel predictor of atrial fibrillation occurrence in the general population

Abstract Background The dysfunction of the autonomic nervous system (ANS) plays an important role in the initiation and maintenance of atrial fibrillation (AF). However, the meaning of high heart rate variability (HRV) in predicting AF is still under debate due to conflicting results in population-based studies. Short-term HRV is conceptually attributed to vagal tone modulation. But recent data suggest that a component of short-term HRV, called heart rate fragmentation, is related to ANS breakdown. On the other hand, parasympathetic activity could be assess by a novel metric, the deceleration capacity (DC). Objective To assess predictive capacity of novel HRV-derived metrics, whether fragmentation indices or parameters of vagal tone, regarding the occurrence of AF in general population during long-term follow-up. Methods A cohort study was designed to prospectively assess the predictive value of ANS activity level among a healthy retired French population, regarding cardiovascular events and mortality. 1011 subjects aged 65 were enrolled in the study from 2000 to 2002. The enrolled population had no history of AF and a low cardiovascular risk. A median follow-up of 17.8 years (16.0–18.5) was managed. HRV data were acquired by 24-h Holter electrocardiogram (ECG) monitoring at baseline and assessed by frequency domain and time domain methods. Heart rate fragmentation using the percentage of inflection points (PIP), and assessment of specific parasympathetic activity using DC were then calculated. The study outcome was the onset of AF during follow-up, defined as a standard 12-lead ECG or Holter recording with ≥30 s of AF. Results AF was diagnosed in 123 patients along the 18-year follow-up, representing a cumulative incidence of 13.4%. Using univariate analysis (Figure 1A), a higher percentage of NN intervals that differ by more than 50 ms from the previous interval (pnn50) and root mean square differences of successive NN intervals (RMSSD) were associated with AF onset (p<0.01). A lower ratio of low-frequency and high-frequency component (LF/HF) was the only frequency-domain parameter found to predict the AF occurrence (p<0.01). The occurrence of AF was predicted by a higher PIP (p<0.01) and lower DC (p<0.01). Through multivariate analysis using clinical parameters that reached statistical significance in univariate analysis (Figure 1B), higher PIP was found as an independent predictor of AF occurrence (HR=2.1, 95% CI: 1.1–3.9, p=0.02), as well as male gender (HR=2.1, 95% CI: 1.1–3.9, p=0.02), and non-sustained supraventricular tachycardia (HR=2.1, 95% CI: 1.1–3.9, p=0.02). Conclusion (see Figure 2) Elevated PIP, a marker of heart rate fragmentation secondary to impaired ANS activity, is an independent predictor of the onset of AF in the healthy general population. Therefore, high HRV associated to AF occurrence could be the consequence of general ANS impairment rather than increased parasympathetic activity. Funding Acknowledgement Type of funding sources: None.

Higher heart rate variability as a predictor of atrial fibrillation in patients with hypertension

The autonomic nervous system (ANS) plays an important role in the initiation and maintenance of atrial fibrillation (AF). However, the meaning of higher heart rate variability (HRV) in predicting AF remains unclear. Among 2100 patients in the Holter registry, a total of 782 hypertensive patients were included in this study. Baseline HRV was measured by time domain and frequency domain methods using 24-h Holter monitoring. The primary outcome was the development of AF. During an average follow-up of 1.1 years, 44 patients developed AF. Higher HRV parameters including high-frequency (P < 0.001), the square root of the mean squared differences of successive NN intervals (P < 0.001), and the percentage of NN intervals that are more than 50 ms different from the previous interval (P < 0.001) were associated with the occurrence of AF in univariate analysis. Premature atrial contractions burden, lower baseline heart rate, age, hemodialysis, coronary artery disease, and chronic heart failure were also associated with AF. In Cox regression analysis, higher HRV (representing excessive autonomic fluctuation) was an independent risk factor for AF. Excessive autonomic fluctuation represented by higher HRV in patients with hypertension was associated with an increased risk of AF.

Assessing Workplace Stress Among Nurses Using Heart Rate Variability Analysis With Wearable ECG Device-A Pilot Study.

This study aims to measure workplace stress of nurses using heart rate variability (HRV) analysis based on data derived from wearable ECG heart rate monitors. The study population consists of 17 nurses at a major public hospital in China. Data was collected from 7 DON nurses (department of neurosurgery; all females; mean age: 31.43 ± 4.50), and 9 ICU nurses (intensive care unit; 8 females and 1 male; mean age: 31.33 ± 5.43). Each participant was asked to wear a wireless ECG heart rate monitor to measure stress level during work, and to complete the Chinese Nurses Stress Response Scale (CNSRS) after work as subjective response criteria. Demographic information, body posture, heart rate, R-R intervals (RRI), low frequency components (LF) and high frequency components (HF) were collected. LF%, LnHF and the squared root of the mean squared differences of successive NN intervals (RMSSD) based on HRV analysis were used to estimate the stress level of nurses. DON nurses reported a higher LF%, lower LnHF and lower RMSSD than ICU nurses. Work shifts were shown to have significant effects on LF%, LnHF and RMSSD respectively, with nurses in long shifts and night shifts reported high stress levels. Higher LF%, lower LnHF and lower RMSSD were found during work shift. Posture analysis revealed negative correlations with LnHF and RMSSD in walking and standing/sitting positions, and a significant negative correlation with LF% in lying-down position. Nurses with higher LF% reported higher CNSRS scores in all subscales, whereas nurses with lower LnHF or RMSSD reported higher CNSRS scores in social phobia and fatigue subscales. The results of this study support the idea that HRV can be used to investigate workplace stress among nurses under real work condition, and can serve as a preventive measure for identifying stress-related illnesses among nurses.

Heart Rate Information-Based Machine Learning Prediction of Emotions Among Pregnant Women.

In this study, the extent to which different emotions of pregnant women can be predicted based on heart rate-relevant information as indicators of autonomic nervous system functioning was explored using various machine learning algorithms. Nine heart rate-relevant autonomic system indicators, including the coefficient of variation R-R interval (CVRR), standard deviation of all NN intervals (SDNN), and square root of the mean squared differences of successive NN intervals (RMSSD), were measured using a heart rate monitor (MyBeat) and four different emotions including “happy,” as a positive emotion and “anxiety,” “sad,” “frustrated,” as negative emotions were self-recorded on a smartphone application, during 1 week starting from 23rd to 32nd weeks of pregnancy from 85 pregnant women. The k-nearest neighbor (k-NN), support vector machine (SVM), logistic regression (LR), random forest (RF), naïve bayes (NB), decision tree (DT), gradient boosting trees (GBT), stochastic gradient descent (SGD), extreme gradient boosting (XGBoost), and artificial neural network (ANN) machine learning methods were applied to predict the four different emotions based on the heart rate-relevant information. To predict four different emotions, RF also showed a modest area under the receiver operating characteristic curve (AUC-ROC) of 0.70. CVRR, RMSSD, SDNN, high frequency (HF), and low frequency (LF) mostly contributed to the predictions. GBT displayed the second highest AUC (0.69). Comprehensive analyses revealed the benefits of the prediction accuracy of the RF and GBT methods and were beneficial to establish models to predict emotions based on autonomic nervous system indicators. The results implicated SDNN, RMSSD, CVRR, LF, and HF as important parameters for the predictions.

Effects of dipping tobacco (Tombak) on heart rate variability among adult males

Objectives:&#x0D; Dipping tobacco is highly prevalent worldwide and in Sudan among adult males and is&#x0D; associated with cardiovascular hazards. The main objective of this study was to determine the effects&#x0D; of ‘tombak’ (local name for dipping tobacco in Sudan) dipping on heart rate variability and autonomic&#x0D; functions among adult males.&#x0D; Methods:&#x0D; Blood pressure and heart rate variability were recorded in 60 male tombak users (study group)&#x0D; at least 5 hours before using the tombak and after 30 minutes of use. Forty male non- users of tombak or&#x0D; any other tobacco products were included as a control group.&#x0D; Results:&#x0D; Measurements 5 hours before tombak dipping revealed statistically significant decrease in high&#x0D; frequency power in tombak users. Acute responses to tombak dipping included statistically significant&#x0D; increase in diastolic blood pressure, increase mean arterial pressure, decrease mean NN and decreased&#x0D; square root of the mean squared differences of successive NN intervals.&#x0D; Conclusions:&#x0D; the study results indicated disturbances in the sympatho-vagal balance with domination of&#x0D; sympathetic effects in the regulation of the cardiac activity and peripheral resistance in tombak users.

The association between methylation in specific cpg sites of slc6a4 gene promoter region and prognosis of acs patients with different level of burnout

Abstract Background Given that psychosocial disorders like depression and burnout are top causes of disease burden, meanwhile have negative effect on the prognosis of acute coronary syndrome (ACS), many studies mounted on their pathogenesis. Recently, epigenetic modifications of stress-related genes like serotonin transporter gene (SLC6A4) have been found to be involved in these disease courses, but the study to investigate the influence of methylation of SLC6A4 gene on the association of these disorders and prognosis of ACS is not found. Objectives To investigate the association of methylation of SLC6A4 gene and prognosis of patients with ACS who were in different level of burnout. Methods Patients with first onset of ACS were enrolled, and their blood sample, demographic and clinical data were collected. Then they were evaluated baseline level of burnout, anxiety, depression, quality of life and heart rate variability (HRV) before discharge, by Copenhagen Burnout Inventory (CBI), Hospital Anxiety and Depression Scale (HADS), 8-item Short Form Generic Health-Related Quality-of-life Questionnaire (SF-8), Seattle Angina Questionnaire (SAQ) and ambulatory electrocardiogram (24h-AECG) respectively. At one-month and six-month's follow-up, their physical performance was evaluated by Short Physical Performance Battery (SPPB) and same indices above were assessed repeatedly. Genomic DNA was extracted from whole blood, and methylation level in 11 CpG sites of SLC6A4 gene promotor region were tested by bisulfite sequencing PCR (BSP) technique. Last, the associations among burnout, anxiety, depression, and their interactions with methylation were analyzed by IBM SPSS Statistics 24.0, so as the association of methylation and the prognosis of ACS. Results 74 patients were enrolled. Chi-square test implied that methylation of CpG7 was more obvious in non-anxiety group compared to anxiety group. And log linear model was used to explore the association among burnout, anxiety, depression, and their interactions with methylation, only the interaction of non-methylation of CpG7 and anxiety was positively correlated to the distribution of frequency. Next, five CpG sites (CpG6–10) were included in generalized estimating equations (GEEs) to analyze the association of methylation and prognosis indices of ACS patients. Results showed that methylation of CpG7 was positively correlated to standard diviation of NN intervals (SDNN), square root of the mean squared differences of successive NN intervals (RMSSD), high frequency (HF), low frequency (LF), very low frequency (VLF), total power (TP), and no significant relations were found among the score of SPPB, SF-8, SAQ and methylation. Conclusions Methylation in CpG7 of SLC6A4 gene promotor region may foretell a good prognosis of ACS patients by being correlated to less anxiety. Epigenetic modifications could be promising biomarkers to help identifying people that need special rehabilitation strategy. Funding Acknowledgement Type of funding sources: Foundation. Main funding source(s): Nature Science Foundation of Yunnan Province; Yunnan Health Training Project of High Level Talents

Explicit and implicit markers of fairness preeminence in criminal judges

Achieving justice could be considered a complex social decision-making scenario. Despite the relevance of social decisions for legal contexts, these processes have still not been explored for individuals who work as criminal judges dispensing justice. To bridge the gap, we used a complex social decision-making task (Ultimatum game) and tracked a heart rate variability measurement: the square root of the mean squared differences of successive NN intervals (RMSSD) at their baseline (as an implicit measurement that tracks emotion regulation behavior) for criminal judges (n = 24) and a control group (n = 27). Our results revealed that, compared to controls, judges were slower and rejected a bigger proportion of unfair offers. Moreover, the rate of rejections and the reaction times were predicted by higher RMSSD scores for the judges. This study provides evidence about the impact of legal background and expertise in complex social decision-making. Our results contribute to understanding how expertise can shape criminal judges’ social behaviors and pave the way for promising new research into the cognitive and physiological factors associated with social decision-making.

Effects of Acute-Partial Sleep Deprivation on High-Intensity Exercise Performance and Cardiac Autonomic Activity in Healthy Adolescents

Performing high-intensity exercise (HIE) in the morning under sleep deprivation may harm the health benefits related to sufficient sleep and HIE. Therefore, the aim of this study was to explore the effects of acute-partial sleep deprivation on HIE performance and cardiac autonomic activity by monitoring heart rate variability (HRV) indices. Twenty-nine healthy male adolescents in college were recruited to perform a one-time HIE session on the treadmill (Bruce protocol) after ≥7 h of normal control sleep (control) and after ≤4 h of acute-partial sleep deprivation (SD). At the beginning of control and SD periods and after exercising under the two sleep conditions, heart rate (HR), standard deviation of normal to normal (SDNN), square root of the mean squared differences of successive NN intervals (RMSSD), normalized low frequency power (LFn), normalized high frequency power (HFn), number of pairs adjacent NN intervals differing by ≥50 ms in the entire recording count divided by the total number of all NN intervals (pNN50), and short axis and long axis value in Poincaré plot (SD1 and SD2) were measured at rest in an upright sitting position. The participants slept 7.63 ± 0.52 and 3.78 ± 0.69 h during control and SD periods, respectively (p &lt; 0.001). Compared with the control participants, those suffering sleep deprivation experienced a significant decrease in exercise duration, RMSSD, HFn, SD1, and pNN50 as well as a significant increase in maximum heart rate during exercise (p &lt; 0.05). SDNN, RMSSD, HFn, SD1, and pNN50 decreased significantly after exercise (p &lt; 0.05 and 0.01 and 0.001, respectively). In summary, acute-partial sleep deprivation affected aerobic exercise performance the next morning and led to decreased cardiac vagus activity and cardiac autonomic dysfunction.

Circadian rhythmicity of heart rate variability and its impact on cardiac autonomic modulation in asthma

ABSTRACT The commonly observed nocturnal attack of asthma is accompanied by circadian variations in airway inflammation and other physiological variables. It is also documented to present with a significantly higher risk of adverse cardiovascular events that are associated with lower heart rate variability (HRV) and depressed sympathetic and enhanced parasympathetic modulations. However, available literature is scarce with regard to the impact of alteration in circadian rhythmicity of long-term HRV and its day–night variation in asthmatic patients. Thus, 72-h continuous recording of RR interval and oxygen saturation was done to study the circadian variability of HRV (in terms of time and frequency domain indices) and also to assess the pattern of alterations in sympathetic and parasympathetic tones at different times of the day in asthmatic patients (n = 32) and healthy control subjects (n = 31). Repeated-measure analysis of variance and independent-samples t-test revealed significantly increased parasympathetic tone [in terms of increased square root of the mean squared differences of successive NN intervals (RMSSD), percentage of number of pairs of adjacent RR interval differing by more than 50 ms (pNN50), standard deviation of NN intervals (SDNN), and high frequency (HF)] with reduced sympathetic activity [decreased low frequency (LF) and LF/HF ratio] at early morning hours (between 04:00 and 10:00 h) in the asthma patients in contrast to the healthy subjects who had opposite response. Also, significant phase delay (p<0.05) of all the HRV indices and SpO2, was evident by cosinor analysis. Therefore, disturbed circadian rhythm of HRV indices and early morning increased parasympathetic tone points toward the possible pathophysiological basis of exacerbated asthmatic symptoms at late night/early morning hours and susceptibility of future cardiovascular pathologies. This also necessitates the assessment of HRV rhythm while dealing with the therapeutic management of asthma patients.

Heart Rate Variability in Young Adults with Persisting Post‐Concussion Symptoms

Objective Recovery following a concussion generally occurs within 7 to 10 days. However, between 10 to 50% of adults experience persistent post-concussion symptoms (PPCS). Alterations in cardiac autonomic function, which may lead to heart rate (HR) dysregulation, could explain some of those persisting symptoms. Our aim was to examine short-term resting heart rate variability (HRV), commonly used as an indicator of cardiac autonomic balance, in a group of subjects with PPCS. Hypothesis HRV parameters associated with cardiac vagal tone will be lower, while parameters associated with cardiac sympathetic activity (SYMP) will be higher in subjects with PPCS when compared to controls. Methods HRV was quantified in individuals experiencing PPCS for more than 4 wks [n=9 (5M/4F); 25 ± 6 y; body mass index (BMI): 25 ± 4 kg/m2] compared to matched healthy controls [n=18 (10M/8F); 27 ± 5 y; BMI: 23 ± 3 kg/m2]. Electrical activity of the heart was recorded continuously for 5 min in resting supine position (3-lead ECG). Signals were reviewed for artifacts and processed using Ensemble-R software (Elucimed, Wellington, NZ). Time-domain analysis of HRV provided the square root of the mean squared differences of successive NN intervals (RMSSD), and the number of interval differences, between successive intervals, greater than 50ms (pNN50). Using spectral power analysis, relative low frequency (LF) power, relative high frequency (HF) power and LF/HF ratio were obtained. RMSSD, pNN50 and relative HF power are generally associated with cardiac vagal tone, whilst relative LF power and LF/HF ratio reflect a mix of cardiac SYMP and vagal activity. Results Mean LF/HF ratio was elevated in PPCS compared to controls (2.4 ± 1.9 vs. 0.9 ± 0.5; p=0.020), owing mainly to a lower relative HF power (28.1 ± 15.8 % vs. 48.5 ± 15.8 %; p=0.004), whilst relative LF power did not differ between groups (p=0.053). There were no significant differences in RMSSD and PNN50 between groups. Conclusion As hypothesized, LF/HF ratio was increased. This shift in cardiac autonomic balance appears to result from a reduction in cardiac vagal tone in young adults with PPCS when assessed in the frequency domain.

Effect of moderate intensity aerobic training on cardiac autonomic system function and nitric oxide levels in middle-aged males with metabolic syndrome

Background and Aims: The sedentary lifestyle in individuals with metabolic syndrome is a main threatening risk for their health. This study aimed to investigate the effects of aerobic exercise with 65% of maximal oxygen consumption on heart rate variability and vascular nitric oxide levels in middle-aged males with metabolic syndrome. Materials and Methods: In total, 30 middle-aged men with metabolic syndrome were randomly divided into control and aerobic training groups. At the pretest and posttest, the values ​​of metabolic risk indices, heart rate variability, and nitric oxide were measured in both groups. The aerobic training group performed aerobic exercise for eight weeks at 65% of maximal oxygen consumption. The data were analyzed using the independent and paired t-tests. Results: According to the results, after comparing the values obtained from the posttest and pretest, there was a significant difference between the training and control groups regarding the fasting blood glucose, triglyceride, metabolic Z score, Standard deviation of NN intervals (SDNN), Square root of the mean squared differences of successive NN intervals (rMSSD), very-low-frequency (VLF), High frequency (HF), and vascular nitric oxide levels. Total cholesterol and low-density lipoprotein levels were significantly different in the aerobic training group, compared to those of the control group and LF as well as LF/HF at the pretest (P=0.01). However, despite slight changes in high lipoprotein and blood pressure levels, there was no significant difference in the aerobic training group, compared to the control group and pre-test. Conclusion: Regular moderate-intensity aerobic exercise can be used as an appropriate exercise protocol to improve cardiovascular function for males with metabolic syndrome.

The predictive value of Holter monitoring in the risk of obstructive sleep apnea.

BackgroundPatients with obstructive sleep apnea (OSA) often present with cardiovascular symptoms. Holter monitors were reported to predict sleep apnea, though were rarely used in everyday clinical practice. In this study, by comparing Holter monitoring to polysomnography (PSG), we try to find out an operable way for clinicians to use Holter to predict OSA risk.MethodsPatients (n=63) suspected of OSA underwent Holter monitoring with concurrent PSG at a sleep center. Respiration and heart rate variability (HRV) indices were calculated from the Holter and compared with PSG indices.ResultsThe sensitivity of the Holter-derived respiratory waveform for OSA was 90.0%, and the specificity was 82.6%. The time domain indices including standard deviation of all NN intervals during 24 hours, mean of standard deviation of the averages of NN intervals in all 5-minute segments, square root of the mean squared differences of successive NN intervals, percentage of beat-to-beat NN interval differences that were more than 50 milliseconds, and the frequency domain index of high frequency decreased in participants with OSA and correlated with the PSG derived indices including apnea-hypopnea index (AHI), oxygen reduction index (ODI) and nadir SaO2. Logistic regression showed that standard deviation of all NN intervals during 24 hours and gender could predict the risk of OSA (P<0.001), with a sensitivity for diagnosing moderate to severe OSA of 87.5% and could accurately distinguish the risk of OSA in 77.8% of patients. Males with standard deviation of all NN intervals during 24 hours ≤177 ms or females with standard deviation of all NN intervals during 24 hours ≤80.9 ms were considered to be at high risk for OSA.ConclusionsCommercial and common parameters from Holter monitoring could predict the risk of OSA with high sensitivity. Therefore, the risk of OSA may be assessed using the Holter examination to improve the diagnosis and treatment rate of OSA.