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https://www.readbyqxmd.com/read/28821492/use-of-the-low-frequency-high-frequency-ratio-of-heart-rate-variability-to-predict-short-term-deterioration-in-emergency-department-patients-with-sepsis
#1
Douglas P Barnaby, Shannon M Fernando, Kevin J Ferrick, Christophe L Herry, Andrew J E Seely, Polly E Bijur, E John Gallagher
OBJECTIVE: To examine the ability of the low-frequency/high-frequency (LF/HF) ratio of heart rate variability (HRV) analysis to identify patients with sepsis at risk of early deterioration. METHODS: This is a prospective observational cohort study of patients with sepsis presenting to the Montefiore Medical Center ED from December 2014 through September 2015. On presentation, a single ECG Holter recording was obtained and analysed to obtain the LF/HF ratio of HRV...
August 18, 2017: Emergency Medicine Journal: EMJ
https://www.readbyqxmd.com/read/28818539/playing-a-rigged-game-inequality-s-effect-on-physiological-stress-responses
#2
Martin S Shapiro, Rhanda Rylant, Amanda de Lima, Andrea Vidaurri, Herman van de Werfhorst
High income and wealth inequality corresponds with high rates of various health and social problems. One possible factor that could be contributing to this correlation is stress experienced by those being treated unfairly in an unequal society. The present experiment attempted to simulate aspects of income inequality in a lab setting while recording several measures of stress. Participants (n=96) were assigned to one of four groups and played a memory game against a confederate opponent to earn "money" to spend in a lab market...
August 14, 2017: Physiology & Behavior
https://www.readbyqxmd.com/read/28815936/combinatorial-effect-of-nicotine-and-black-tea-on-heart-rate-variability-useful-or-harmful
#3
S Joukar, M Sheibani
The effect of nicotine on heart rate variability (HRV) is controversial. Autonomic nervous system is the main regulator of heart rhythm, and heart rate variability is an appropriate index to assessment of the effects of the autonomic system on heart. In this study, the combination effect of nicotine and black tea consumption on sympatho-vagal balance and heart rate variability was investigated in rats. Male Wistar rats were randomized into four groups as control, tea (2.5 g/100 cc, daily), nicotine (2 mg/kg/d) and tea plus nicotine groups which treated for 28 days, and in the 29th day, their electrocardiograms (lead II) were recorded...
June 2017: Autonomic & Autacoid Pharmacology
https://www.readbyqxmd.com/read/28814850/increased-parasympathetic-cardiac-modulation-in-patients-with-acute-exacerbation-of-copd-how-should-we-interpret-it
#4
Erika Zavaglia Kabbach, Adriana Mazzuco, Audrey Borghi-Silva, Ramona Cabiddu, Aline Galvão Agnoleto, Jessica Fernanda Barbosa, Luiz Carlos Soares de Carvalho Junior, Renata Gonçalves Mendes
BACKGROUND: Cardiac autonomic modulation (CAM) is impaired in patients with stable COPD. Exacerbation aggravates the patients' health status and functional capacity. While the clinical and functional effects of exacerbation are known, no studies investigated CAM during exacerbation and whether there is a relationship between CAM and functional capacity and dyspnea. METHODS: Thirty-two patients with moderate to severe COPD were enrolled into two groups: stable COPD (GSta, n=16) and acute exacerbation of COPD (GAE, n=16)...
2017: International Journal of Chronic Obstructive Pulmonary Disease
https://www.readbyqxmd.com/read/28812280/effect-of-missing-inter-beat-interval-data-on-heart-rate-variability-analysis-using-wrist-worn-wearables
#5
Hyun Jae Baek, JaeWook Shin
Most of the wrist-worn devices on the market provide a continuous heart rate measurement function using photoplethysmography, but have not yet provided a function to measure the continuous heart rate variability (HRV) using beat-to-beat pulse interval. The reason for such is the difficulty of measuring a continuous pulse interval during movement using a wearable device because of the nature of photoplethysmography, which is susceptible to motion noise. This study investigated the effect of missing heart beat interval data on the HRV analysis in cases where pulse interval cannot be measured because of movement noise...
August 15, 2017: Journal of Medical Systems
https://www.readbyqxmd.com/read/28807718/autonomic-regulation-of-systemic-inflammation-in-humans-a-multi-center-blinded-observational-cohort-study
#6
Gareth L Ackland, Gary Minto, Martin Clark, John Whittle, Robert Cm Stephens, Thomas Owen, Pradeep Prabhu, Ana Gutierrez Del Arroyo
OBJECTIVE: Experimental animal models demonstrate that autonomic activity regulates systemic inflammation. By contrast, human studies are limited in number and exclusively use heart rate variability (HRV) as an index of cardiac autonomic regulation. HRV measures are primarily dependent on, and need to be corrected for, heart rate. Thus, independent autonomic measures are required to confirm HRV-based findings. Here, the authors sought to replicate the findings of preceding HRV-based studies by using HRV-independent, exercise-evoked sympathetic and parasympathetic measures of cardiac autonomic regulation to examine the relationship between autonomic function and systemic inflammation...
August 11, 2017: Brain, Behavior, and Immunity
https://www.readbyqxmd.com/read/28806776/the-very-low-frequency-band-of-heart-rate-variability-represents-the-slow-recovery-component-after-a-mental-stress-task
#7
Harunobu Usui, Yusuke Nishida
The very low-frequency (VLF) band of heart rate variability (HRV) has different characteristics compared with other HRV components. Here we investigated differences in HRV changes after a mental stress task. After the task, the high-frequency (HF) band and ratio of high- to low-frequency bands (LF/HF) immediately returned to baseline. We evaluated the characteristics of VLF band changes after a mental stress task. We hypothesized that the VLF band decreases during the Stroop color word task and there would be a delayed recovery for 2 h after the task (i...
2017: PloS One
https://www.readbyqxmd.com/read/28802637/blood-pressure-responses-to-dietary-sodium-association-with-autonomic-cardiovascular-function-in-normotensive-adults
#8
Evan L Matthews, Michael S Brian, David G Edwards, Sean D Stocker, Megan M Wenner, William B Farquhar
Blood pressure responses to dietary sodium vary widely person-to-person. Salt sensitive rodent models display altered autonomic function, a trait thought to contribute to poor cardiovascular health. Thus, we hypothesized that increased salt sensitivity (SS) in normotensive humans would be associated with increased muscle sympathetic nerve activity (MSNA), decreased high frequency heart rate variability (HF-HRV), and decreased baroreflex sensitivity. Healthy normotensive men and women completed 1week of high (300mmol·day(-1)) and 1week of low (20mmol·day(-1)) dietary sodium (random order) with 24h mean arterial pressure (MAP) assessed on the last day of each diet to assess SS...
August 6, 2017: Autonomic Neuroscience: Basic & Clinical
https://www.readbyqxmd.com/read/28801725/optimization-of-soluble-expression-and-purification-of-recombinant-human-rhinovirus-type-14-3c-protease-using-statistically-designed-experiments-isolation-and-characterization-of-the-enzyme
#9
Georgia Antoniou, Irineos Papakyriacou, Christos Papaneophytou
Human rhinovirus (HRV) 3C protease is widely used in recombinant protein production for various applications such as biochemical characterization and structural biology projects to separate recombinant fusion proteins from their affinity tags in order to prevent interference between these tags and the target proteins. Herein, we report the optimization of expression and purification conditions of glutathione S-transferase (GST)-tagged HRV 3C protease by statistically designed experiments. Soluble expression of GST-HRV 3C protease was initially optimized by response surface methodology (RSM), and a 5...
August 11, 2017: Molecular Biotechnology
https://www.readbyqxmd.com/read/28800081/autonomic-dysfunction-after-mild-traumatic-brain-injury
#10
Dmitry Esterov, Brian D Greenwald
A mild traumatic brain injury (mTBI) is a complex pathophysiologic process that has a systemic effect on the body aside from solely an impairment in cognitive function. Dysfunction of the autonomic nervous system (ANS) has been found to induce abnormalities in organ systems throughout the body, and may contribute to cardiovascular dysregulation and increased mortality. Autonomic dysfunction, also known as dysautonomia, has been studied in moderate and severe TBI, and has emerged as a major contributing factor in the symptomatology in mTBI as well...
August 11, 2017: Brain Sciences
https://www.readbyqxmd.com/read/28798697/cardiac-autonomic-modulation-and-the-kinetics-of-heart-rate-responses-in-the-on-and-off-transient-during-exercise-in-women-with-metabolic-syndrome
#11
Lucas R B E Silva, Antonio R Zamunér, Paulo Gentil, Fagner M Alves, Acácia G F Leal, Viviane Soares, Maria S Silva, Marcus F Vieira, Karina Simões, Gustavo R Pedrino, Ana C S Rebelo
Objective: To test whether women with metabolic syndrome (MS) have impairments in the on- and off-transients during an incremental test and to study whether any of the MS components are independently associated with the observed responses. Research Design and Methods: Thirty-six women aged 35-55 years were divided into a group with MS (MSG, n = 19) and a control group (CG, n = 17). R-R intervals (RRi) and heart rate variability (HRV) were calculated on a beat-to-beat basis and the heart rate (HR) at the on- and off-transient were analyzed during an incremental cardiopulmonary exercise test (CPET)...
2017: Frontiers in Physiology
https://www.readbyqxmd.com/read/28796128/high-intensity-interval-exercises-acute-impact-on-heart-rate-variability-comparison-between-whole-body-and-cycle-ergometer-protocols
#12
Gustavo Z Schaun, Fabrício B Del Vecchio
Study aimed to compare the effects of two high-intensity interval exercises (HIIT) protocols on heart rate variability (HRV). Twelve young adult males (23.3 ± 3.9 years, 177.8 ± 7.4 cm, 76.9 ± 12.9 kg) volunteered to participate. In a randomized cross-over design, subjects performed two HIIT protocols, one on a cycle ergometer (TBT; eight 20 s bouts at 170% Pmax interspersed by 10 s rest) and another with whole-body calisthenic exercises (MCR; eight 20 s all-out intervals interspersed by 10 s rest). HRV outcomes in the time, frequency and non-linear domains were assessed on three moments: (a) pre-session; (b) immediately post-session; and (c) 24h post-session...
August 4, 2017: Journal of Strength and Conditioning Research
https://www.readbyqxmd.com/read/28792445/effects-of-short-forest-bathing-program-on-autonomic-nervous-system-activity-and-mood-states-in-middle-aged-and-elderly-individuals
#13
Chia-Pin Yu, Chia-Min Lin, Ming-Jer Tsai, Yu-Chieh Tsai, Chun-Yu Chen
The present study investigated changes in autonomic nervous system activity and emotions after a short (2 h) forest bathing program in the Xitou Nature Education Area (XNEA), Taiwan. One hundred and twenty-eight (60.0 ± 7.44 years) middle-aged and elderly participants were recruited. Physiological responses, pulse rate, systolic and diastolic blood pressure, heart rate variability (HRV), and psychological indices were measured before and after the program. We observed that pulse rate, systolic and diastolic blood pressure were significantly lower after the program, which indicated physiological benefits from stress recovery...
August 9, 2017: International Journal of Environmental Research and Public Health
https://www.readbyqxmd.com/read/28783577/positive-affect-and-parasympathetic-activity-evidence-for-a-quadratic-relationship-between-feeling-safe-and-content-and-heart-rate-variability
#14
Joana Duarte, José Pinto-Gouveia
There has been an increased interest in the study of underlying autonomic correlates of emotions. This study tests the hypothesis that high levels of high-frequency heart rate variability (HF HRV) are associated with positive emotions. In addition, we hypothesize that this association will differ according to the type of positive emotion. Also, based on recent findings, we tested the hypothesis that this relationship would be nonlinear. Resting-state HRV was collected and self-report measures of different positive emotions were administered to a sample of 124 volunteers...
July 31, 2017: Psychiatry Research
https://www.readbyqxmd.com/read/28782130/left-atrial-phasic-function-and-heart-rate-variability-in-patients-with-systemic-sclerosis-a-new-part-of-the-old-puzzle
#15
Marijana Tadic, Maja Zlatanovic, Cesare Cuspidi, Ana Stevanovic, Vesna Kocijancic, Sinisa U Pavlovic, Nemanja Damjanov, Vera Celic
OBJECTIVE: We aimed to research left atrial (LA) phasic function and heart rate variability (HRV), as well as their relationship, in subjects with uncomplicated systemic sclerosis (SSc). METHODS: The investigation involved 44 SSc patients and 33 age-matched healthy controls. All participants underwent clinical examination, serological tests, 24-hours Holter monitoring, and echocardiographic examination including strain analysis. RESULTS: Maximum, minimum, and pre-A LA volumes and volume indices were higher in the SSc patients than in the controls...
August 7, 2017: Echocardiography
https://www.readbyqxmd.com/read/28777974/impact-of-skin-to-skin-contact-on-the-autonomic-nervous-system-in-the-preterm-infant-and-his-mother
#16
L Butruille, A Blouin, J De Jonckheere, S Mur, T Margez, T Rakza, L Storme
Before, during and after mother-newborn skin-to-skin contact (SSC), parasympathetic activity was evaluated by heart rate variability (HRV) analysis. SSC had a favorable impact on maternal and premature infant parasympathetic activities with a more pronounced response for neonates when the basal HRV values were lower, without modifications of EDIN scores, temperatures or oxygen saturation.
August 1, 2017: Infant Behavior & Development
https://www.readbyqxmd.com/read/28777827/effects-of-visual-flow-direction-on-signs-and-symptoms-of-cybersickness
#17
Alireza Mazloumi Gavgani, Deborah M Hodgson, Eugene Nalivaiko
Our objective was to assess the influence of visual flow direction on physiological changes and symptoms elicited by cybersickness. Twelve healthy subjects (6 male and 6 female) were exposed to a 15-min virtual ride on a rollercoaster on two different days in a counterbalanced manner, such half of participants were facing forward during the first ride while another half was facing backward. Forehead skin conductance, heart rate and HRV parameters (SDRR, RMSSD) were collected as objective measures; subjective symptoms were assessed with the Motion Sickness Assessment Questioner immediately after exposure...
2017: PloS One
https://www.readbyqxmd.com/read/28774440/heart-rate-variability-metrics-for-fine-grained-stress-level-assessment
#18
Tânia Pereira, Pedro R Almeida, João P S Cunha, Ana Aguiar
BACKGROUND AND OBJECTIVES: In spite of the existence of a multitude of techniques that allow the estimation of stress from physiological indexes, its fine-grained assessment is still a challenge for biomedical engineering. The short-term assessment of stress condition overcomes the limits to stress characterization with long blocks of time and allows to evaluate the behaviour change in real-world settings and also the stress level dynamics. The aim of the present study was to evaluate time and frequency domain and nonlinear heart rate variability (HRV) metrics for stress level assessment using a short-time window...
September 2017: Computer Methods and Programs in Biomedicine
https://www.readbyqxmd.com/read/28771509/combined-effect-of-prefrontal-transcranial-direct-current-stimulation-and-a-working-memory-task-on-heart-rate-variability
#19
Stevan Nikolin, Tjeerd W Boonstra, Colleen K Loo, Donel Martin
Prefrontal cortex activity has been associated with changes to heart rate variability (HRV) via mediation of the cortico-subcortical pathways that regulate the parasympathetic and sympathetic branches of the autonomic nervous system. Changes in HRV due to altered prefrontal cortex functioning can be predicted using the neurovisceral integration model, which suggests that prefrontal hyperactivity increases parasympathetic tone and decreases contributions from the sympathetic nervous system. Working memory (WM) tasks and transcranial direct current stimulation (tDCS) have been used independently to modulate brain activity demonstrating changes to HRV in agreement with the model...
2017: PloS One
https://www.readbyqxmd.com/read/28771038/classification-of-driving-workload-affected-by-highway-alignment-conditions-based-on-classification-and-regression-tree-algorithm
#20
Jiangbi Hu, Ronghua Wang
OBJECTIVE: Guaranteeing a safe and comfortable driving workload can contribute to reducing traffic injuries. In order to provide safe and comfortable threshold values, this study attempted to classify driving workload from the aspects of human factors mainly affected by highway geometric conditions, and to determine the thresholds of different workload classifications. This paper stated a hypothesis that the values of driver workload change within a certain range. METHODS: Driving workload scales were stated based on a comprehensive literature review...
August 3, 2017: Traffic Injury Prevention
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