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Results 151 - 200 of 802
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Suzuki Shigehiro - - 2008
The purpose of this study was to examine the timing of recovery of the high-frequency (HF) component of heart rate variability (HRV) after exercise in female distance runners using frequency analysis of HRV. Twenty-two female young (n=11; YG) and middle-aged (n=11; MG) distance runners participated in this study. The two ...
Chang Rei-Yeuh - - 2008
OBJECTIVE: The objective of this study was to evaluate the effect of t'ai chi (TC) on heart rate variability (HRV) from baseline to 9 months in patients with coronary artery disease (CAD). DESIGN: A comparative trial was undertaken comparing the acute and long-term effect of TC on HRV in patients ...
Guazzi Marco - - 2008
AIMS: Exercise intolerance occurs in both systolic and diastolic heart failure (HF). Exercise oscillatory breathing (EOB) is a powerful predictor of survival in patients with systolic HF. In diastolic HF, EOB prevalence and prognostic impact are unknown. METHODS AND RESULTS: A total of 556 HF patients (405 with systolic HF ...
Wu Shr-Da - - 2008
Phenomenon of the heart rate variability (HRV) during various meditation techniques has been reported. However, most of these techniques emphasized the skill of slow breathing (<0.15 Hz). This paper reports our study on HRV during meditation which emphasizes inward attention. Inward attention has been an important approach for the Zen-meditation ...
Ebara Takeshi - - 2008
Adjustable sit-stand workstations, which are designed to allow workers to sit and stand autonomously while working, were examined to identify the effects on workers' musculoskeletal discomfort, alertness and performance. Twenty-four healthy subjects participated in the study. The subjects were required to do an English transcription task for 150 min under ...
Vanderlei L C M - - 2008
The aim of the present study was to compare heart rate variability (HRV) at rest and during exercise using a temporal series obtained with the Polar S810i monitor and a signal from a LYNX(R) signal conditioner (BIO EMG 1000 model) with a channel configured for the acquisition of ECG signals. ...
Meert Natalie - - 2009
BACKGROUND: Although different on-line convective removal strategies are available, there are no studies comparing the efficiency of solute removal for the three main options [post-dilution haemodiafiltration (post-HDF), pre-dilution haemodiafiltration (pre-HDF) and pre-dilution haemofiltration (pre-HF)] in parallel. METHODS: In this study, we compared post-HDF (Polyflux 170), pre-HDF (Polyflux 170) and pre-HF ...
Arena Ross - - 2010
BACKGROUND: The heart rate increase during exercise (DeltaHR) and heart rate recovery (HRR) have demonstrated prognostic value in several investigations, but its application in the heart failure (HF) population is limited, particularly in a beta-blocked (BB) cohort. METHODS: Five-hundred and twenty subjects with HF underwent cardiopulmonary exercise testing to determine ...
Collier S R - - 2009
AIM: Cardiac autonomic modulation and baroreflex sensitivity (BRS) are altered in individuals with hypertension. Aerobic exercise (AE) training has been shown to improve both measures, yet little is known about the effects of resistance exercise (RE). The purpose of this study was to examine the heart rate variability (HRV) and ...
Hédreville Mona - - 2008
This study compared the nocturnal autonomic nervous system (ANS) activity in seven sickle cell trait (SCT) carriers and six subjects with normal hemoglobin in response to exercise Sympathetic and parasympathetic indices of nocturnal ANS were measured in the two groups before and 24 and 48 h after a strenuous exercise ...
Dampney R A L - - 2008
Defensive behaviour evoked by mild or moderate psychological stress as well as increased activity and arousal are part of everyday life in humans and other animals. Both defensive behaviour and exercise are associated with marked and often quite stereotyped changes in autonomic and respiratory function. These patterned responses are generated ...
Andrzejak Ryszard - - 2008
It is possible that electromagnetic field (EMF) generated by mobile phones (MP) may have an influence on the autonomic nervous system (ANS) and modulates the function of circulatory system. The aim of the study was to estimate the influence of the call with a mobile phone on heart rate variability ...
Zheng Aisong - - 2008
BACKGROUND: CoQ10 has come to be widely used as a dietary supplement, and daily intake of it has increased in recent years. CoQ10 is produced in all living organisms and is an essential coenzyme for energy synthesis in the mitochondria and an important scavenger of reactive oxygen species. OBJECTIVE: This ...
Nolan Robert P - - 2008
BACKGROUND: Heart rate variability (HRV) is reported as a surrogate index for clinical outcome in trials of secondary prevention strategies for coronary artery disease (CAD), but a standardized guide for interpreting HRV change is not established. DESIGN: We evaluated HRV change in trials with CAD patients who received conventional medications ...
Guazzi Marco - - 2009
Previous research has demonstrated an increase in large vessel stiffness in patients with heart failure (HF). Furthermore, heart rate recovery (HRR) may be negatively impacted by increased arterial stiffness secondary to altered baroreceptor discharge. The purpose of the present study was to determine if chronic phosphodiesterase 5 (PDE5) inhibition with ...
Klemenc Matjaz - - 2008
Cardiac arrhythmias are associated with an increase in sympathetic activity (reflected in increased heart rate) and a simultaneous decrease in rhythmical fluctuations of sympathetic activity [reflected in decreased heart rate variability (HRV)]. As hypoxia is a well known trigger for cardiac arrhythmias, and carbohydrate loading a known sympatho-excitatory stimulus, the ...
Gilder Michael - - 2008
Physically active individuals demonstrate increased heart rate variability (HRV) during rest compared to sedentary individuals, but the impact of different volumes of regular exercise on the HRV response to postural change is not well understood. This study investigates change in HRV following orthostasis in seventy-two young women who exercise at ...
Moffitt Julia A - - 2008
The hindlimb-unloaded (HU) rat model elicits cardiovascular deconditioning and simulates the physiological adaptations to microgravity or prolonged bed rest in humans. Although psychological deficits have been documented following bed rest and spaceflight in humans, few studies have explored the psychological effects of cardiovascular deconditioning in animal models. Given the bidirectional ...
Cottin François - - 2008
The aim of the study was to assess the instantaneous spectral components of heart rate variability (HRV) and systolic blood pressure variability (SBPV) and determine the low-frequency (LF) and high-frequency baroreflex sensitivity (HF-BRS) during a graded maximal exercise test. The first hypothesis was that the hyperpnea elicited by heavy exercise ...
Tezini Geisa C S V - - 2008
We have investigated the ovariectomy effects on the cardiovascular autonomic adaptations induced by aerobic physical training and the role played by nitric oxide (NO). Female Wistar rats (n=70) were divided into five groups: Sedentary Sham (SS); Trained Sham (TS); Trained Hypertensive Sham treated with N(G)-nitro-L-arginine methyl ester (L-NAME) (THS); Trained ...
Leicht A S - - 2008
Previous studies have demonstrated the high reproducibility of heart rate variability (HRV) measures in adults while little information exists concerning HRV reproducibility in children. Subsequently, the aim of the current study was to examine the moderate-term reproducibility of heart rate and frequency domain measures of HRV during rest and light ...
Rickards Caroline A - - 2008
INTRODUCTION: In the setting of remote military triage, when physical access to the patient is not possible, traditional physiological measurements available to a combat medic may not differentiate between a wounded soldier and an active soldier. We tested the hypothesis that changes in high-frequency R-R interval spectral power (RRI HF) ...
Martinmäki Kaisu - - 2008
We evaluated the effects of low-dose endurance training on autonomic HR control. We assessed the heart rate variability (HRV) of 11 untrained male subjects (36.8 +/- 7.2 years) at rest and during an incremental maximal aerobic exercise test prior to a 7-week preparatory period and prior to and following a ...
Sousa Lidiane - - 2009
Regular exercise training is considered to be capable of beneficially modifying the autonomic balance in healthy subjects. We studied the association between vagal HRV indexes and the level of physical activity in Chagas disease patients and control subjects. Although in controls habitual physical activity was closely associated with vagal HRV ...
Gatta G - - 2008
The lateral-medial displacement (LF) and the overall drift from a straight path (DT) were quantified and compared in 5 top-level (TLS) and 5 low-level (LLS) crawl swimmers. Sixteen repetitions of 25-m crawl at increasing intensity were performed and videotaped. The performances were divided into 3 intensities (< 80 %, 80 ...
Gratze Gerfried - - 2008
AIMS: To elucidate the mechanisms of orthostatic intolerance (OI) after endurance exercise which are incompletely understood. METHODS AND RESULTS: We investigated beat-to-beat haemodynamic and autonomic parameters in 51 male athletes during supine rest and after active standing the day before and 2 h after a marathon run. None of the ...
Lahiri Marc K - - 2008
Certain abnormalities of autonomic function in the setting of structural cardiovascular disease have been associated with an adverse prognosis. Various markers of autonomic activity have received increased attention as methods for identifying patients at risk for sudden death. Both the sympathetic and the parasympathetic limbs can be characterized by tonic ...
Friot Emmanuel - - 2008
Many research works have focused on multichannel soundfield reproduction during the past decade, and complete systems are now commercially available for 3D sound control e.g., with Wave Field Synthesis. However, the usual underlying approximation of free-field propagation is not valid when reproducing high level low frequency noise, such as a ...
Gilder Michael - - 2008
In this study, we investigated heart rate variability in women who exercise regularly, but with differing volumes of physical activity. Forty women participated and were allocated to either a "high" or "moderate" activity group. Heart rate as R-R intervals was recorded during supine rest and analysed using time domain, frequency ...
Niemelä Teemu H - - 2008
PURPOSE: To test the association between exercise mode and the recovery pattern of baroreflex sensitivity (BRS) after exercise. METHODS: The study population included healthy male subjects (N = 12, age: 31 +/- 3 yr). Four different interventions were performed in a randomized order: 1) aerobic exercise session on a bicycle ...
Sangkatumvong S - - 2008
The objective of this study was to non-invasively assess cardiac autonomic control in subjects with sickle cell anemia (SCA) by tracking the changes in heart rate variability (HRV) that occur following brief exposure to a hypoxic stimulus. Five African-American SCA patients and seven healthy control subjects were recruited to participate ...
Schmitt Laurent - - 2008
Opuntia ficus indica (OFI) has many physiological effects, but a relationship between OFI and heart-rate variability (HRV) has never been established. The aim of this study was to describe the effects of a diet supplement of OFI on HRV in athletes. The first day, heart rate (HR) was measured at ...
Witte Klaus K A - - 2008
Changes within skeletal muscle, including augmentation of its capacity to elicit reflex increases in both efferent muscle sympathetic nerve activity (MSNA) and ventilation during work, contribute significantly to exercise intolerance in heart failure (HF). Previously, we demonstrated that peak oxygen uptake (pVO(2)) in HF relates inversely to MSNA at rest ...
Ninio Daniel M - - 2008
Dietary fish oil supplementation and regular physical activity can improve outcomes in patients with established CVD. Exercise has been shown to improve heart rate variability (HRV), a predictor of cardiac death, but whether fish oil benefits HRV is controversial. Obese adults at risk of future coronary disease have impaired HRV ...
Emshoff Rüdiger - - 2008
OBJECTIVES: Laser Doppler flowmetry (LDF) is a noninvasive method to assess pulpal blood-flow (PBF). The purpose of this study was (1) to test whether Le Fort I (LF-I) osteotomy may show tooth type-related effects on LDF measurements, and (2) to investigate whether LF-I and tooth type may predict adverse PBF ...
Arena Ross - - 2008
BACKGROUND: Exercise oscillatory ventilation (EOV) occurs in a sub-group of patients with increased heart failure (HF) severity and poorer prognosis. The purpose of this investigation was to examine the prognostic value of the largest ventilatory oscillation characteristics in HF patients. METHODS: One hundred fifty-four subjects diagnosed with HF underwent cardiopulmonary ...
Cammarota Camillo - - 2008
The heartbeat time series of the electrocardiogram recorded during exercise test clearly reflects the physiological control mechanism of the autonomic nervous system on heart rate. This series shows both decreasing and increasing trends and variability of the variance. We analyse the series of intervals between two consecutive extrema, i.e. the ...
Arroyo-Morales Manuel - - 2008
OBJECTIVE: The usefulness of massage as a recovery method after high-intensity exercise has yet to be established. We aimed to investigate the effects of whole-body massage on heart rate variability (HRV) and blood pressure (BP) after repeated high-intensity cycling exercise under controlled and standardized pretest conditions. METHODS: The study included ...
Imai Kenji - - 2008
To clarify the mechanism of site-specific effects of acupuncture on gastric motor function, we studied the simultaneous recording of gastric motility and electrocardiogram (ECG) for heart rate variability (HRV) analysis in conscious rats. Gastric motility and ECG were recorded before, during and after electroacupuncture (EA) at ST-36 (hind limb) or ...
Chiou S-S - - 2008
Betel-quid is widely used around the world as a stimulant for the autonomic nervous system. The aim of this study was to assess the effect of betel-quid chewing on autonomic nervous modulation by using spectral heart rate variability (HRV) analysis. Twenty healthy young adults were included in this study. Each ...
Negrao Carlos Eduardo - - 2008
Although neurohumoral excitation is the hallmark of heart failure (HF), the mechanisms underlying this alteration are not entirely known. Abnormalities in several systems contribute to neurohumoral excitation in HF, including arterial and cardiopulmonary baroreceptors, central and peripheral chemoreceptors, cardiac chemoreceptors, and central nervous system abnormalities. Exercise intolerance is characteristic of ...
McKelvie Robert S - - 2008
Heart failure (HF) patients are often counseled to limit their physical activity, however, this advice may not be appropriate. Data has accumulated supporting the effectiveness of exercise training to improve fitness levels and symptoms. There are also data suggesting that training may reduce mortality and morbidity in HF patients. Studies ...
Cavallari Jennifer M - - 2008
Although research suggests that particles influence cardiac autonomic response as evidenced by decreases in heart rate variability (HRV), the time course of the response remains unclear. Using a crossover panel study, we monitored 36 male boilermaker welders, occupationally exposed to metal-rich particulate matter (PM) to investigate the temporal trend of ...
de la Cruz Torres B - - 2008
OBJECTIVE: To analyse HRV at rest in healthy people and in patients with acute myocardial infarction (AMI) and how it changes during aerobic exercise. METHODS: The heartbeat signal was recorded beat to beat for 15 minutes at rest and 15 minutes while pedalling in 10 healthy and active men (H ...
Karavirta Laura - - 2008
Large interindividual variation in maximal heart rate (HRmax) may not be accounted for by age alone. In order to evaluate a novel method in the prediction of HRmax, this study examined the profile of HR variability (HRV) during exercise in 40-67 years old men (n = 74). R-R intervals were ...
Princi Tanja - - 2008
Studies of autonomic cardiac nervous system activity during acute exposure to hypobaric hypoxia have suggested a depression of autonomic functions and a shift in the sympatho-vagal balance towards relatively more sympathetic and less parasympathetic activity at higher hypoxic levels . This study was performed on nine non-acclimatized middle-aged healthy men ...
Yetter Mike - - 2008
The purpose of the present study was to investigate the effects of performing heavy back squats (HBS) and heavy front squats (HFS) on the average speed during each 10-m interval of 40-m sprint trials. In a randomized, cross-over design, 10 strength-trained men performed a HBS, HFS, or control treatment before ...
Earnest Conrad P - - 2008
BACKGROUND: Decreased heart rate variability (HRV) is associated with a higher risk of mortality. Overall, postmenopausal women have lower levels of HRV than premenopausal women, which may be additionally complicated by lifestyle related behaviors such as physical inactivity and obesity. Though cardiorespiratory exercise training increases HRV, little is known regarding ...
Yeh Gloria Y - - 2008
OBJECTIVE: To review the physiological and psychosocial effects of a 12-week T'ai Chi program (TC) in patients with heart failure (HF) as previously reported in a clinical trial. METHODS: We randomized 30 patients with chronic HF (left ventricular ejection fraction < or =40%) to receive TC plus usual care (n ...
Tiinanen Suvi - - 2008
Cardiac baroreflex is described by baroreflex sensitivity (BRS) from blood pressure and heart rate interval (RRi) fluctuations. However, respiration affects both blood pressure and RRi via mechanisms that are not necessarily of baroreflex origin. To separate the effects of baroreflex and respiration, metronome-guided breathing in a high frequency band (HF, ...
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