Rate Variability Changes Research Articles

Heart rate variability changes during task shifting testing in pre‐symptomatic Alzheimer’s disease

AbstractBackgroundEarly detection of Alzheimer’s disease (AD) is vital to begin and monitor treatments. However, as AD pathology begins long before the onset of symptoms, early detection is difficult. Previous studies have suggested differences in the cardiac and autonomic nervous systems (ANS) in AD patients, providing a possible non‐invasive marker of disease onset. The goal of this study is to compare heart rate variability (HRV) measures, representative of cardiac and ANS function, at rest as well as during cognitive testing to assess the use of HRV as a possible marker of pre‐symptomatic AD.MethodAll participants are cognitively healthy (CH) separated into two subgroups based on ratios of amyloid/tau proteins in cerebrospinal fluid (CSF): normal (CH‐NAT, n=22) and pathological (CH‐PAT, n=36), which represents pre‐symptomatic AD. Heart rate variability (HRV) was assessed during 5‐minute intervals at rest and during Task Shifting testing. Participants were required to name the color or word of a colored word for each stimulus by pressing a button, with two sequential stimuli per trial. The trial could be switching (color‐word or word‐color) or repeat (color‐color or word‐word). ECG traces from subgroups of CH‐NATs (n=8) and CH‐PATs (n=13) were initially screened to remove ectopic beats, followed by identification of normal RR‐intervals (NN). HRV was analyzed as standard deviation of NN (SDNN), root mean squared of successive differences (RMSSD) in the time domain as well as high (HF) and low frequency (LF) in the frequency domain to assess changes to autonomic, and particularly parasympathetic, input to the heart.ResultComparing HRV changes assessed during rest and the task shifting testing in each individual, differences became apparent between CH‐NAT and CH‐PAT groups. In the CH‐NAT group, little to no change in SDNN and RMSSD occurred during cognitive testing from rest. The CH‐PAT group however showed a 20 percent drop in both SDNN and RMSSD during testing, indicating an imbalance of the ANS.ConclusionThis study provides a new approach and technique using HRV to non‐invasively differentiate between normal and pre‐symptomatic AD in cognitively healthy people.

Abstract 13500: Association Between Breast Cancer and Cardiac Autonomic Function as Measured by Heart Rate Variability in the Women’s Health Initiative

Background: Autonomic dysfunction (AD) as measured by heart rate variability (HRV) is associated with increased risk of cardiovascular disease (CVD) and breast cancer. No study has utilized a large prospective multi-center cohort of diverse women to assess differences in HRV associated with incident breast cancer. Objectives: To identify heart rate variability changes in women with breast cancer compared to controls in the Women’s Health Initiative (WHI). Methods: In a retrospective cohort study, we utilized 5,031 women in the WHI CT cohort who were breast cancer free at baseline and compared 1) those with incident breast cancer v. 2) those who were breast cancer free during the ECG follow-up period as controls. HRV was calculated utilizing 10-second ECG with two measures of two-domain HRV: standard deviation of all normal-to-normal RR intervals (SDNN) and the root mean square of successive differences in normal-to-normal RR intervals (rMSSD). HRV was measured from ECGs collected at baseline, years 3, 6, and 9 in the comparison groups. An adjusted mixed linear model was used to evaluate the differences in SDNN and rMSSD comparing women with incident breast cancer to controls. Cardiovascular risk factors utilized in the adjusted model were determined via questionnaire at baseline. Results: At baseline, women with incident breast cancer diagnosed by years 3, 6, or 9 were significantly older (median age 63 vs. 61, P<0.0001) and had a higher prevalence of hypertension (35% vs. 32%, P=0.02). SDNN at years 3 and 6 in women with breast cancer compared to controls was significantly lower (P=0.0002, P=0.03 respectively). As well, rMSSD was significantly lower at year 3 compared to controls (P<0.0001) ( Figure 1 ). Conclusions: HRV as a measure of AD is significantly lower in women with incident breast cancer compared to women without breast cancer. Reduction in HRV is associated with CVD outcomes in the literature. Our study suggests HRV may predict CVD in breast cancer patients.

Wearable Epileptic Seizure Prediction System with Machine-Learning-Based Anomaly Detection of Heart Rate Variability.

A warning prior to seizure onset can help improve the quality of life for epilepsy patients. The feasibility of a wearable system for predicting epileptic seizures using anomaly detection based on machine learning is evaluated. An original telemeter is developed for continuous measurement of R-R intervals derived from an electrocardiogram. A bespoke smartphone app calculates the indices of heart rate variability in real time from the R-R intervals, and the indices are monitored using multivariate statistical process control by the smartphone app. The proposed system was evaluated on seven epilepsy patients. The accuracy and reliability of the R-R interval measurement, which was examined in comparison with the reference electrocardiogram, showed sufficient performance for heart rate variability analysis. The results obtained using the proposed system were compared with those obtained using the existing video and electroencephalogram assessments; it was noted that the proposed method has a sensitivity of 85.7% in detecting heart rate variability change prior to seizures. The false positive rate of 0.62 times/h was not significantly different from the healthy controls. The prediction performance and practical advantages of portability and real-time operation are demonstrated in this study.

The relationship between chemotherapy-induced peripheral neuropathy and heart rate variability.

820 Background: Chemotherapy-induced peripheral neuropathy (CIPN) is a common complication related to chemotherapeutic agents and dose accumulation. Initial symptoms are known to be sensory including numbness and pain whereas autonomic symptoms are the latest. Autonomic dysfunction is related to heart rate variability (HRV) change which may precede the symptoms. But, the relationship between CIPN and heart rate variability is not fully evaluated. Therefore, we aimed to evaluate the HRV with CIPN-related questionnaires in patients underwent chemotherapy. Methods: Fifty-five patients with gastrointestinal cancers were enrolled in this cross-sectional cohort study. Patients have received chemotherapeutic agents such as paclitaxel, cisplatin, and oxaliplatin. CIPN was diagnosed using National Cancer Institute Common Toxicity Criteria for Adverse Event (NCI-CTCAE version 4.03). We evaluated the quality of life, CIPN symptom scale, and HRV. Results: Forty-two patients were male (76.4%) and mean age was 63.2 years old. Thirty-nine patients (71.0%) had CIPN of more than grade I according to NCI-CTCAE. Patients with CIPN represented lower physical and role functions. The standard deviation of all normal R-R intervals (SDNN) was decreased in the CIPN group. Parasympathetic tone (high frequency band) were decreased, but sympathetic activity (low frequency band/high frequency band) were increased in CIPN. Conclusions: CIPN affected the quality of life in gastrointestinal cancer patients underwent chemotherapy. HRV was related to CIPN. Further study may be needed to check the feasibility of HRV as early biomarkers for detecting CIPN. [Table: see text]

Heart Rate Variability Changes in the Integrated Yoga Program: Results and Implications

Background. Different methods are used to study cardiovascular parameters. Of these, heart rate variability (HRV) is a relevant marker for both athletes and physically active people. With regards to physical activity, yoga has become a popular form of activity in the recent years. In fact, research has indicated that yoga is a useful modality for both the management and prevention of several cardiovascular conditions. The purpose of the current study was to observe HRV dynamics in young women during a 6-month yoga intervention.Methods. We recruited 13 women from multiple yoga studios. All participants were practicing Hatha yoga 2 times a week for 6 months. Data were collected: a) at baseline, b) 2 months after the yoga intervention, c) 4 months after the intervention and d) 6 months after the intervention. We used wireless Bluetooth electrocardiogram (ECG) recording device. ECG HVR parameters and heart rate (HR) were used for data analysis.Results. HR dynamics showed no differences during the 6-month yoga intervention. Meanwhile, vLF parameter after relaxation and LF/HF ratio after body scan meditation significantly changed after yoga intervention. No changes were observed in LF or HF parameter dynamics.Conclusion. Our results suggest that 6 months twice per week yoga practice influences vLF and LF/HF ratio, especially during relaxation and body scan meditation. We also suggest that healthy women could benefit from practicing body scan meditation. In conclusion, through modification of emotion reactivity, regular practice of yoga can help improve stress response and offset negative consequences associated with the stress process.Keywords: yoga, heart rate variability, women’s health, ECG, stress.

Heart Rate Variability Changes during Sahaja Yoga Meditation

Background & Objectives
 Yoga and meditation is now widely accepted world wide as an effective tool to combat stress. Heart Rate Variability (HRV) is a noninvasive tool to measure sympathetic and parasympathetic function of the autonomic nervous system. Yoga, by modulating stress, has shown to decrease the activity of sympathetic component of autonomic nervous system and enhance parasympathetic component. Only few studies have compared HRV at baseline with HRV during or after single session of yoga. Thus, this study was undertaken with the objectives to compare HRV changes of Sahaja Yoga Meditators in resting state with their Meditation state and to compare these changes with HRV changes in the control group in resting and meditation mimicking state.
 Method
 A prospective randomized controlled study was conducted. The study group comprised of 30 randomly selected long term Sahaja yoga mediators and a control group of 30 subjects with no prior practice of any kind of meditation. HRV was recorded in both the groups in normal resting state, during meditation (yoga group) and with eyes closed (mimicking meditation in control group).
 Results
 Study showed decrease in LF (sympathetic activity) increase in HF (parasympathetic activity) and decrease in LF/HF ratio thus implying a more relaxed, parasympathetic dominant state, in the yoga group during meditation.
 Conclusion
 The study shows Sahaja Yoga meditation leads to a parasympathetic dominant (relaxed) state and thus can be used as an effective mind body technique to combat stress.

Effect of banana leaf bath (a type of heliotherapy) on short-term heart rate variability changes in healthy individuals: A pilot study

IntroductionBanana leaf bath (BLB) [a type of heliotherapy (sunbath)] is being used in various diseases like skin diseases, obesity and other metabolic disorders in many naturopathy hospitals in India. However, its precise physiology is less understood. Thus, this study was conducted to evaluate the effect of BLB on heart rate variability (HRV) in healthy individuals. Materials and methodsTwenty-eight (12 males, 16 females) healthy individuals with the mean (standard deviation) age of 23.39 (3.70) years were recruited. All the subjects underwent a 30 min session of BLB (lie down in a place with direct sunlight exposure while covering the entire body with banana leaves). Assessments were taken before and after the intervention. ResultsResults of this study showed a significant increase in the mean of the intervals between adjacent QRS complexes or the instantaneous HR (RR Intervals), standard deviation of RR Intervals (SDNN), the square root of the mean of the sum of the squares of differences between adjacent normal-to-normal (NN) intervals (RMSSD), the number of interval differences of successive NN intervals >50 ms (NN50), and the proportion derived by dividing NN50 by the total number of NN intervals (pNN50) and a significant reduction in heart rate (HR), while no significant difference in low frequency (LF), high-frequency (HF) and LF/HF ratio in the study group. ConclusionResults of this study suggest that 30 min of BLB might be effective in reducing HR and in improving HRV towards vagal dominance in healthy individuals.

Preliminary Evidence That Resting State Heart Rate Variability Predicts Reactivity to Tactile Stimuli in Rett Syndrome.

Patients with Rett syndrome may manifest altered pain perception/experience and are vulnerable to conditions associated with chronic pain. Pain response is difficult to measure, however, because of severe communicative impairment. There is also documented autonomic dysfunction, including decreased heart rate variability. Given the relation between pain and the autonomic nervous system, we tested the feasibility of using resting heart rate variability to predict nonverbal pain/discomfort behavior during a standardized modified quantitative sensory test in Rett syndrome. All stimulus applications resulted in increased behavioral reactivity compared to baseline, with repeated von Frey significantly greater than all other stimuli. Resting heart rate variability predicted behavioral reactivity to repeated von Frey. These preliminary findings provide feasibility evidence for an integrated autonomic-sensory measurement approach and are consistent at a construct level with preclinical evidence in Rett syndrome. Further work is needed to determine how heart rate variability changes during stimulus application.

Peripheral neuropathy in HIV patients on antiretroviral therapy: Does it impact function?

HIV-associated distal sensory polyneuropathy (DSP), with or without neuropathic symptoms, can develop after anti-retroviral therapy (ART). Symptoms frequently involve small fibres but reports on autonomic dysfunction in HIV-DSP are sparse. We studied an HIV-infected cohort after 5 years of ART, and report on the frequency and severity of autonomic symptoms and the impact of DSP on everyday function. This cross-sectional study comprised of participants from a community-based South African HIV-clinic. The Brief Peripheral Neuropathy Screen and reduced Total Neuropathy Score evaluated neuropathic symptoms/signs. DSP was defined as ≥2 symmetrical DSP-signs, and symptomatic DSP when accompanied by neuropathic symptoms. Autonomic symptoms questionnaires, heart rate variability and postural blood pressure changes were assessed. The Lower Extremity Functional Scale (LEFS) was completed. The 67 participants had a median age of 42 years and median ART exposure of 7 years with viral suppression in 84%. Most (81%) met our criteria for DSP and 36% had additional neuropathic symptoms. Autonomic symptoms and signs (above normative values) were present in 15% and more likely in those with symptomatic DSP (P < .001). Participants with DSP, even without symptoms, had lower LEFS scores (P ≤ .039) than those without. HIV-DSP is prevalent and impacts on daily living.

Early Postnatal Heart Rate Variability in Healthy Newborn Infants.

BackgroundDespite the increasing interest in fetal and neonatal heart rate variability (HRV) analysis and its potential use as a tool for early disease stratification, no studies have previously described the normal trends of HRV in healthy babies during the first hours of postnatal life.MethodsWe prospectively recruited 150 healthy babies from the postnatal ward and continuously recorded their electrocardiogram during the first 24 h after birth. Babies were included if born in good condition and stayed with their mother. Babies requiring any medication or treatment were excluded. Five-minute segments of the electrocardiogram (non-overlapping time-windows) with more than 90% consecutive good quality beats were included in the calculation of hourly medians and interquartile ranges to describe HRV trends over the first 24 h. We used multilevel mixed effects regression with auto-regressive covariance structure for all repeated measures analysis and t-tests to compare group differences. Non-normally distributed variables were log-transformed.ResultsNine out of 16 HRV metrics (including heart rate) changed significantly over the 24 h [Heart rate p < 0.01; Standard deviation of the NN intervals p = 0.01; Standard deviation of the Poincaré plot lengthwise p < 0.01; Cardiac sympathetic index (CSI) p < 0.01; Normalized high frequency power p = 0.03; Normalized low frequency power p < 0.01; Total power p < 0.01; HRV index p = 0.01; Parseval index p = 0.03], adjusted for relevant clinical variables. We observed an increase in several HRV metrics during the first 6 h followed by a gradual normalization by approximately 12 h of age. Between 6 and 12 h of age, only heart rate and the normalized low frequency power changed significantly, while between 12 and 18 h no metric, other than heart rate, changed significantly. Analysis with multilevel mixed effects regression analysis (multivariable) revealed that gestational age, reduced fetal movements, cardiotocography and maternal chronic or pregnancy induced illness were significant predictors of several HRV metrics.ConclusionHeart rate variability changes significantly during the first day of life, particularly during the first 6 h. The significant correlations between HRV and clinical risk variables support the hypothesis that HRV is a good indicator of overall wellbeing of a baby and is sensitive to detect birth-related stress and monitor its resolution over time.

Creative challenge: Regular exercising moderates the association between task-related heart rate variability changes and individual differences in originality.

Coping with mental challenges is vital to everyday functioning. In accordance with prominent theories, the adaptive and flexible adjustment of the organism to daily demands is well expressed in task-related changes of cardiac vagal control. While many mental challenges are associated with increased effort and associated decreased task-related heart rate variability (HRV), some cognitive challenges go along with HRV increases. Especially creativity represents a cognitive process, which not only results from mental effort but also from spontaneous modes of thinking. Critically, creativity and HRV are associated with regular exercising and fitness. Furthermore, the cross-stressor adaptation theory suggests that changes in cardiac reactions to physical challenges may generalize to mental challenges. In line with this idea the amount of regular exercising was hypothesized to moderate the association between HRV changes and creativity. A sample of 97 participants was investigated. They reported the amount of regular exercise and their ECG was measured at baseline and during a creativity task. An association between task-related HRV changes and originality as a function of participants’ amount of regular exercise was found. Participants reporting more regular exercising produced more original ideas when they had higher HRV increases during the task, while more sedentary participants showed the opposite association. Results suggest that individuals with a higher amount of regular exercise achieve higher originality probably via the engagement in more spontaneous modes of thinking, while more sedentary people may primarily benefit from increased mental effort. This supports the conclusion that higher creativity can be achieved by different strategies.

Heart Rate Variability During Nocturnal Sleep and Daytime Naps in Patients With Narcolepsy Type 1 and Type 2.

Heart rate variability is a noninvasive measure of autonomic function. The aim of this study was to determine the risk of cardiovascular autonomic dysfunction during sleep in patients with narcolepsy. The effect of daytime napping was also examined in patients with narcolepsy type 1 and type 2. Polysomnography recordings and multiple sleep latency tests from 11 patients with narcolepsy type 1 (N1) and 20 patients with narcolepsy type 2 (N2) were included and compared with 12 healthy controls. Heart rate variability values (measured by time- and frequency-domain parameters) were calculated using electrocardiography data from the polysomnography-multiple sleep latency test recordings. As an indicator of increasing sympathovagal imbalance, the low-frequency/high-frequency ratio was higher in all patients than in controls during non-rapid eye movement (NREM)-2 stage sleep (P ≤ 0.01). The root mean square of successive RR interval differences was lower (indicating parasympathetic tone) in N1 patients compared with N2 patients during REM sleep (P ≤ 0.04). In addition, decreased heart rate variability values were observed during sleep-onset REM-negative multiple sleep latency test periods compared with sleep-onset REM-positive periods. Heart rate variability abnormalities during sleep and the role of these changes on the development of cardiovascular diseases must be investigated in prospective follow-up studies of patients with narcolepsy. Heart rate variability changes during night sleep, daytime napping, and presence of sleep-onset REM periods may affect the life-threatening events.

Heart Rate Variability Changes during Sahaja Yoga Meditation

Background & Objectives Yoga and meditation is now widely accepted world wide as an effective tool to combat stress. Heart Rate Variability (HRV) is a noninvasive tool to measure sympathetic and parasympathetic function of the autonomic nervous system. Yoga, by modulating stress, has shown to decrease the activity of sympathetic component of autonomic nervous system and enhance parasympathetic component. Only few studies have compared HRV at baseline with HRV during or after single session of yoga. Thus, this study was undertaken with the objectives to compare HRV changes of Sahaja Yoga Meditators in resting state with their Meditation state and to compare these changes with HRV changes in the control group in resting and meditation mimicking state. Method A prospective randomized controlled study was conducted. The study group comprised of 30 randomly selected long term Sahaja yoga mediators and a control group of 30 subjects with no prior practice of any kind of meditation. HRV was recorded in both the groups in normal resting state, during meditation (yoga group) and with eyes closed (mimicking meditation in control group). Results Study showed decrease in LF (sympathetic activity) increase in HF (parasympathetic activity) and decrease in LF/HF ratio thus implying a more relaxed, parasympathetic dominant state, in the yoga group during meditation. Conclusion The study shows Sahaja Yoga meditation leads to a parasympathetic dominant (relaxed) state and thus can be used as an effective mind body technique to combat stress.

Pre-treatment condition effects on blood pressure and heart rate variability change in patients with arterial hypertension on therapy.

To study the relationship of the initial clinical and functional state of patients with arterial hypertension (AH) with the dynamics of daily indices of blood pressure (BP) and sinus rhythm on antihypertensive therapy. 38 patients were examined (general clinical examination, electrocardiography, echocardiography, daily bifunctional monitoring with the determination of weighted average rhythmogram variations - WARV, clinical and biochemical analysis of blood, glycated hemoglobin, thyroid hormones) and distribyted according to the use of hypotensive drugs of main classes and combined therapy AH. Dynamic monitoring of the effectiveness of treatment was carried out (after 2-4 weeks, then every 1-2 months), clinically and with bifunctional monitoring, correction of therapy. The observation period was 8 months. By the end of the study, 27 patients had target blood pressure, significant decrease in systolic / diastolic blood pressure (10/5 mm Hg and more) occurred in 30 patients. A correlation was found between the effectiveness of antihypertensive treatment and the initial clinical and instrumental parameters of patients: age, heart size (including left ventricular hypertrophy - LVH), thyroid stimulating blood hormone (TSH) level and fasting blood glucose (within normal limits). The level of WARV also correlated with these indicators and was significantly higher in patients who achieved a significant reduction in blood pressure. No significant dynamics of WARV was detected. No relationship between baseline blood pressure with WARV and their changes were identified. The connection of the myocardial mass index with the level of TSH and glycated hemoglobin was demostrated. The WARV reflects the severity of organic heart changes associated with age, disease duration, metabolic profile, LVH - heart damage as a target organ in AH, but is not suitable for analyzing its functional changes within one stage of the disease.

Heart Rate Variability Changes From Traditional vs. Ultra-Short-Term Recordings in Relation to Preseason Training Load and Performance in Futsal Players.

Nakamura, FY, Antunes, P, Nunes, C, Costa, JA, Esco, MR, and Travassos, B. Heart rate variability changes from traditional vs. ultra-short-term recordings in relation to preseason training load and performance in futsal players. J Strength Cond Res 34(10): 2974-2981, 2020-The aims of this study were to analyze heart rate variability (HRV) changes in futsal players during preseason training using both "criterion" (10-minute) and ultra-shortened (2-minute) measures, and to determine whether they were related to changes in the Yo-Yo Intermittent Recovery Test, level 1 (Yo-Yo IR1) performance and accumulated training load (TL). Eleven male competitive futsal players (age = 25.19 ± 4.70 years; body mass = 73.15 ± 11.70 kg; and height = 176.90 ± 5.01 cm) volunteered for the study. Data collection took place during the first to the fourth weeks of preseason training. Training load was monitored with session ratings of perceived exertion. The total distance (TD) covered during the Yo-Yo IR1 was recorded during week 1 and week 4. Heart rate variability was measured through the log-transformed root mean square of successive normal-to-normal interval differences using the ultra-short analysis, with its weekly mean (lnRMSSDM) and coefficient of variation (lnRMSSDCV) recorded, and by means of the criterion method (weeks 1 and 4). lnRMSSDM was likely higher at week 4 compared with week 1 using both criterion and ultra-short recordings. Moderate-to-large correlations were found between changes in the lnRMSSDM and lnRMSSDCV values and changes in TL and TD (r values ranged from -0.48 to 0.65). Changes in ultra-short HRV measures (i.e., increase in lnRMSSDM and decrease in lnRMSSDCV) during futsal preseason were associated with increased performance. The players who accumulated higher perceived TLs displayed smaller improvements in the Yo-Yo IR1 performance and HRV.

Heart rate variability changes in major depressive disorder during sleep: Fractal index correlates with BDI score during REM sleep

We investigated the relationship between autonomic nervous system activity during each sleep stage and the severity of depressive symptoms in patients with major depressive disorder (MDD) and healthy control subjects. Thirty patients with MDD and thirty healthy control subjects matched for sex, age, and body mass index completed standard overnight polysomnography. Depression severity was assessed using the Beck Depression Inventory (BDI). Time- and frequency-domain, and fractal HRV parameters were derived from 5-min electrocardiogram segments during light sleep, deep sleep, rapid eye movement (REM) sleep, and the pre- and post-sleep wake periods. Detrended fluctuation analysis (DFA) alpha-1 values during REM sleep were significantly higher in patients with MDD than in control subjects, and a significant correlation existed between DFA alpha-1 and BDI score in all subjects. DFA alpha-1 was the strongest predictor for the BDI score, along with REM density as a covariate. This study found that compared with controls, patients with MDD show reduced complexity in heart rate during REM sleep, which may represent lower cardiovascular adaptability in these patients, and could lead to cardiac disease. Moreover, DFA alpha-1 values measured during REM sleep may be useful as an indicator for the diagnosis and monitoring of depression.

Heart rate variability changes and its association with the development of severe retinopathy of prematurity

To evaluate differences in autonomic nervous system (ANS) activity associated with the development of retinopathy of prematurity. Heart rate variability (HRV) as an indicator of ANS activity was calculated in two groups of premature infants: (1) a treatment group of infants who developed type 1 ROP and underwent treatment and (2) a control group of infants who did not develop ROP more severe than stage 1 and who were matched to the treatment group in terms of age, weight, and similar risk factors, including similar frequency of intraventricular hemorrhage, bronchopulmonary dysplasia, and sepsis. HRV was analyzed during the first 5days of life, within 5days of initial ROP examination, and within 5days of ROP treatment for the treatment group or, for controls, on the day of last electrocardiogram data prior to discharge. Calculations were performed for the high frequency, low frequency, and low frequency-high frequency values of the HRV components for all infants. Between the initial ophthalmologic evaluation and the final evaluation, there was a tendency for reduction in both the low- and high-frequency components of the HRV indices in the treatment group, whereas there was a tendency for an increase in both components of the HRV indices in the control group. The difference in the rate of change of the high frequency between groups was statistically significant (P=0.021). Disruption in ANS activity may play an important role in the development and severity of ROP.

Heart rate and heart rate variability change while falling asleep during driving a car

Heart rate and heart rate variability change while falling asleep during driving a car

First-year estimated glomerular filtration rate variability after pre-end-stage renal disease program enrollment and adverse outcomes of chronic kidney disease.

Scarce evidence associates the first-year estimated glomerular filtration rate (eGFR) variability and longitudinal change scales concomitantly to the risk of developing end-stage renal disease (ESRD), acute coronary syndrome (ACS) and death following pre-ESRD program enrollment in chronic kidney disease (CKD). We conducted a prospective cohort study of 5092 CKD patients receiving multidisciplinary care between 2003 and 2015 with careful ascertainment of ESRD, ACS and death during the follow-up. First-year eGFR variability and longitudinal change scales that were based on all first-year eGFR measurements included coefficient of variation of eGFR (eGFR-CV), percent change (eGFR-PC), absolute difference (eGFR-AD), slope (eGFR-slope) and area under the curve (AUC). A total of 786 incident ESRD, 292 ACS and 410 death events occurred during the follow-up. In the multiple Cox regression, the fully adjusted hazard ratios (HRs) of progression to ESRD for each unit change in eGFR-CV, eGFR-PC, eGFR-AD, eGFR-slope, eGFR-AUC were 1.03 [95% confidence interval (CI) 1.02-1.04], 1.04 (1.03-1.04), 1.16 (1.14-1.18), 1.16 (1.14-1.17) and 1.04 (1.03-1.04), respectively. The adjusted HRs for incident ESRD comparing the extreme with the reference quartiles of eGFR-CV, eGFR-PC, eGFR-AD, eGFR-slope and eGFR-AUC were 2.67 (95% CI 2.11-3.38), 8.34 (6.33-10.98), 19.08 (11.89-30.62), 13.08 (8.32-20.55) and 6.35 (4.96-8.13), respectively. Similar direction of the effects on the risk of developing ACS and mortality was observed. In the 2 × 2 risk matrices, patients with the highest quartile of eGFR-CV and concomitantly with the most severely declining quartiles of any other longitudinal eGFR change scale had the highest risk of all outcomes. The dynamics of eGFR changes, both overall variability and longitudinal changes, over the first year following pre-ESRD program enrollment are crucial prognostic factors for the risk of progression to ESRD, ACS and deaths among patients with CKD. A risk matrix combining the first-year eGFR variability and longitudinal change scales following pre-ESRD enrollment is a novel approach for risk characterization in CKD care. Randomized trials in CKD may be required to ascertain comparable baseline eGFR dynamics.

A Multiclass Arousal Recognition using HRV Nonlinear Analysis and Affective Images.

This paper reports on a multiclass arousal recognition system based on autonomic nervous system linear and nonlinear dynamics during affective visual elicitation. We propose a new hybrid method based on Lagged Poincaré Plot (LPP) and symbolic analysis, hereinafter called LPPsymb. This tool uses symbolic analysis to evaluate the irregularity of the trends of Lagged Poincaré Plot (LPP) quantifiers over the lags, and is here applied to investigate complex Heart Rate Variability (HRV) changes during emotion stimuli. In the experimental protocol 22 healthy subjects were elicited through a passive visualization of affective images gathered from the international affective picture system. LPPsymb and standard HRV analysis (defined in time and frequency domains) were applied to HRV series of one minute length. Then, an ad-hoc pattern recognition algorithm based on quadratic discriminant classifier was implemented and validated through a leave-onesubject-out procedure. The best performance of the proposed classification algorithm for recognizing the four classes of arousal was obtained using nine features comprising heartbeat complex dynamics, achieving an accuracy of 71.59%.