Search Results
Results 351 - 400 of 813
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Tuomainen Petri - - 2005
HRV and HRT are independent predictors of cardiovascular mortality. Aging reduces HRV, but results from the physical exercise trials are controversial. The primary aim was to study changes in heart rate variability (HRV) and heart rate turbulence (HRT) in a six-year controlled randomized trial at regular low to moderate intensity ...
Takase B - - 2005
Betaxolol hydrochloride is a beta1-selective antagonist that produces vasodilation in patients with hypertension and ischemic heart disease. The goal of the present study was to characterize the effect of betaxolol on heart rate variability indices (HRV), a well-established prognostic marker. Symptom limited-treadmill exercise testing was performed in 17 hypertensive patients ...
Takase B - - 2005
Complications of interferon (IFN) therapy include cardiac arrhythmias, impaired cardiac function and myocardial ischemia. Decreased heart rate variability (HRV) indices, impaired exercise tolerance and decreased left ventricular (LV) function are related to unfavorable outcome of heart disease. To investigate the effect of IFN therapy on HRV, exercise tolerance and cardiac ...
Swope Viki B - - 2005
OBJECTIVE: To determine if matrix metalloproteinase-1 (MMP-1) was involved in the premature degradation of the dermal component in cultured skin substitutes (CSS) prepared with cells from burn patients. METHODS AND RESULTS: CSS 645 and 647 were prepared from clinical human fibroblasts (HF) and keratinocytes (HK) that demonstrated premature degradation of ...
Middlekauff Holly R - - 2005
BACKGROUND: Studies have shown that neither ejection fraction nor hemodynamic abnormalities during exercise in chronic heart failure (HF) correlate with symptoms of fatigue and exhaustion. The concept that exercise limitation in patients with chronic HF is due to abnormal hemodynamics during exercise has been revised to acknowledge that the skeletal ...
Iwanaga Makoto - - 2005
Previous studies of physiological responses to music showed inconsistent results, which might be attributable to methodological differences. Heart rate variability has been used to assess activation of the sympathetic and the parasympathetic nervous systems. The present study aimed to examine heart rate variability with repetitive exposure to sedative or excitative ...
Spadacini Giammario - - 2006
BACKGROUND: It is widely recognised that during exercise vagal heart rate control is markedly impaired but blood pressure control may or may not be retained. We hypothesised that this uncertainty arose from the differing responses of the vagus (fast) and sympathetic (slow) arms of the autonomic effectors, and to differing ...
Iwasa Yukie - - 2005
BACKGROUND: There have been few studies that have reported on heart rate variability and the development of autonomic nervous function in children. This study investigated the relationship between heart rate variabilities at night and physical activity in children. METHODS: The study subjects were 29 children, including 17 boys and 12 ...
Raczak Grzegorz - - 2005
BACKGROUND: The aim of the present study was to investigate the effect of a single bout of mild exercise on autonomic nervous system activity in healthy subjects. METHODS AND RESULTS: The study group comprised 18 healthy males, aged between 20 and 24 years, who had not been training regularly for ...
Tulppo Mikko P - - 2005
BACKGROUND: Altered fractal heart rate (HR) dynamics occur during various disease states, but the physiological background of abnormal fractal HR behavior is not well known. We tested the hypothesis that the fractal organization of human HR dynamics is determined by the balance between sympathetic and vagal outflow. METHODS AND RESULTS: ...
Urakawa Kayoko - - 2005
Many studies have been conducted on physiological responses of music, yielding controversial results. In the present study, we examined whether music affects the exercise-induced changes in the autonomic nervous system activity in twelve healthy female college students. On the first day, the subjects were asked to rest, exercise, and then ...
Emter Craig A - - 2005
Data regarding the effectiveness of chronic exercise training in improving survival in patients with congestive heart failure (CHF) are inconclusive. Therefore, we conducted a study to determine the effect of exercise training on survival in a well-defined animal model of heart failure (HF), using the lean male spontaneously hypertensive HF ...
Faulkner Melissa Spezia - - 2005
Incidence rates of both type 1 and type 2 diabetes mellitus (DM) are increasing in youth and may eventually contribute to premature heart disease in early adulthood. This investigation explored the influence of type of diabetes, gender, body mass index (BMI), metabolic control (HbA1c), exercise beliefs and physical activity on ...
Berger E - - 2005
Drug-induced prolongation of the QTc interval is an important marker for potential proarrhythmic action. Prolongation of the QTc interval results from alteration of the ionic currents that regulate cardiac repolarisation. Such effects may result from direct drug action or alternatively they could also occur indirectly by drug-induced modulation of autonomic ...
Demaree Heath A - - 2006
Relative to watching in a natural manner, people asked to suppress or exaggerate their facial response to a negative emotional stimulus experience greater activation of the sympathetic nervous system but report a similar subjective emotional experience. The present research extends prior research on response modulation in two important ways. First, ...
Arif M - - 2005
Heart rate variability (HRV) analysis is a non-invasive and reliable means to assess an autonomic nervous system (ANS) function. Heart rate is a non-stationary signal that may contain indicators of current diseases and sometimes warnings about impending diseases. In this paper, we have proposed the threshold-based acceleration change index (TACI) ...
Zaliūnas Remigijus - - 2005
OBJECTIVE: To estimate the influence of therapy with amlodipine (A) or lacidipine (L) on heart rate variability (HRV) time and frequency domain parameters in hypertensive patients with stable angina pectoris and isolated left ventricular diastolic dysfunction. METHODS: After a 1-week washout period, the patients were randomized to receive amlodipine 10 ...
Kawasaki T - - 2006
To determine whether the Bezold-Jarisch reflex or enhancement of vagal nerves, which are preferentially distributed in the inferoposterior myocardium, results from exercise induced ischaemia in this region. On the basis of exercise myocardial scintigraphy and coronary angiography, 145 patients were classified as follows: group I, 34 patients with inferoposterior ischaemia; ...
Nishioka Yasuko - - 2005
BACKGROUND: In some stroke patients blood pressure (BP) fluctuates extensively during medical rehabilitation, so the present study investigated the influence of autonomic nervous dysfunction on the change in BP during exercise. METHODS AND RESULTS: The subjects consisted of 55 stroke inpatients (males, 29; mean age, 58.8 years old; ischemic/hemorrhagic etiology, ...
Dean Abigail S - - 2005
BACKGROUND: Vasoreactivity is known to be impaired in heart failure patients; however, it has not been determined whether standard medical therapy for end-stage heart failure patients (ES-HF) ameliorates this impairment. Therefore, we sought to investigate flow-mediated dilation (FMD) responses in ES-HF with normal or near normal cardiac indices from continuous ...
Li Zengyong - - 2005
The objective of this study was to assess the effects of acupuncture applied at Hegu (LI 4) points and Neiguan (PC6) points on heart rate variability (HRV) in normal subjects under fatigue and non-fatigue states using power spectral analysis. Twenty-nine normal male subjects were randomly divided into three groups. Subjects ...
Toronov Vladislav Y - - 2005
We use near-infrared spectroscopy to investigate hemodynamic changes in humans during a breath holding exercise and their influence on the BOLD fMRI signal. We have quantitatively compared the BOLD fMRI signals with the hemoglobin concentration changes using correlation analysis of NIRS and fMRI data.
Melenovsky Vojtech - - 2005
This study evaluated the effect of beta blockade on cardiac autonomic control and its dependence on heart rate change. The relations between RR interval duration, heart rate variability (HRV), and baroreflex sensitivity (BRS) were studied in 111 healthy men and in 21 male volunteers before and after a 100-mg oral ...
Andrási Terézia B - - 2005
Although patients suffering from heart failure (HF) have an increased incidence of nonocclusive mesenteric ischemia after opened heart surgery, the impact of cardiopulmonary bypass with cardiac arrest (CPB) on mesenteric vascular circulation in such situation remains unexplored. Therefore, the present study investigates the effects of CPB on mesenteric vascular reactivity, ...
Martinelli F S - - 2005
The purpose of the present study was to determine if autonomic heart rate modulation, indicated by heart rate variability (HRV), differs during supine rest and head-up tilt (HUT) when sedentary and endurance-trained cyclists are compared. Eleven sedentary young men (S) and 10 trained cyclists (C) were studied. The volunteers were ...
Parekh Alpa - - 2005
PURPOSE: To examine cardiac autonomic modulation, via heart rate variability (HRV), after exercise bouts at 50% (LO) and 80% (HI) of VO2 reserve (VO2R). METHODS: Thirteen male volunteers (age: 25.7+/-3 yr) exercised on a treadmill at either LO or HI (randomly assigned) on separate days, expending 300 kcal during each ...
Oosthuyse Tanja - - 2005
Submaximal exercise performance has not previously been assessed in the late follicular phase of the menstrual cycle, which is associated with a pre-ovulatory surge in oestrogen. Therefore, we compared cycling time trial performance during the early follicular (EF), late follicular (LF) and mid-luteal (ML) phase of the menstrual cycle in ...
Arena Ross - - 2005
BACKGROUND: Mechanisms leading to heart failure (HF) are numerous. Etiology-based differences are, however, frequently not taken into account when assessing results of an exercise test. The purpose of this investigation is to: (1) compare subject characteristics and ventilatory expired gas measures demonstrating clinical value between subjects with ischemic and non-ischemic ...
Iwasaki Ken-Ichi - - 2005
An intermittent exposure to artificial hypergravity with physical exercise by a human centrifuge may provide a countermeasure against various physiological problems after space flight. To test the effects of hypergravity with ergometric exercise on dynamic regulation of heart rate during weightlessness, we quantified autonomic cardiovascular control before and after head-down-tilt ...
Javorka Michal - - 2005
Autonomic neuropathy is a common complication of the diabetes mellitus (DM). The significance of its early diagnosis is very high because the mortality of the patients with this complication is elevated. Considering the effort to apply new mathematical methods to cardiac dysregulation diagnosis, the major aim of the study was ...
Sandercock Gavin R H - - 2005
INTRODUCTION: Chronic exercise training produces a resting bradycardia that is thought to be due partly to enhanced vagal modulation. PURPOSE: The aim of the present study was to determine the effects of exercise training on heart rate and measures of heart rate variability associated with vagal cardiac modulation and to ...
Schuchert Andreas - - 2005
BACKGROUND: The routine determination of heart rate variability (HRV) from surface ECGs is based on RR intervals because of the difficulty to precisely locate the P-wave fiducial point on surface ECG recordings. The aim of the study was to assess the changes of RR, PP, and PR intervals at rest ...
Zhong Xu - - 2005
Cardiovascular autonomic modulation during 36 h of total sleep deprivation (SD) was assessed in 18 normal subjects (16 men, 2 women, 26.0 +/- 4.6 yr old). ECG and continuous blood pressure (BP) from radial artery tonometry were obtained at 2100 on the first study night (baseline) and every subsequent 12 ...
Todder D - - 2005
BACKGROUND: The bipolar affective disorder is long been speculated to have an autonomic involvement. Nonlinear analysis of heart rate variability has recently been shown to be a reliable noninvasive test for quantitative assessment of the central sympathovagal interaction that modulates cardiovascular autonomic function. METHODS: We studied 32 euthymic bipolar patients ...
Riediker Michael - - 2005
On September 11, 2001, terrorists attacked the United States. By coincidence, a North Carolina highway patrol trooper was wearing an ambulatory ECG Holter monitor at this time as part of an air pollution study. Heart rate variability parameters were analyzed: standard deviation of normal to normal beat intervals (SDNN) and ...
Nazeran Homer - - 2005
LifeWave energy patches are novel nanoscale semiconducting biomolecular antennas, that when placed in the oscillating bioelectromagnetic field of the body, resonate at frequencies in unison with certain biomolecules in the cells and signal specific metabolic pathways to accelerate fat metabolism. As a consequence of accelerated fat burning more cellular energy ...
Pichon Aurélien - - 2005
BACKGROUND: The autonomic nervous system plays a primary role in regulating airway caliber, and its dysfunction is likely to contribute to the pathogenesis of airways diseases. Moreover, some findings support the hypothesis that autonomic dysfunction and/or dysregulation contributes to the pathogenesis of airway hyperresponsiveness (AHR). Heart rate variability (HRV) spectral ...
Zimmermann Marc - - 2005
Repetitive monomorphic idiopathic (RMI) ventricular tachycardia (VT) occurs typically in patients without structural heart disease, originates in most cases from the right ventricular outflow tract, and can often be induced by exercise or isoproterenol. This study analyzed the dynamic changes in autonomic tone immediately before the spontaneous onset of RMIVT ...
Chang Chi-Hsien - - 2005
Acupuncture is known to influence autonomic nervous activity. Acupuncture on Zusanli points has been shown to enhance the regularity of gastric myoelectrical activity and accelerate gastric emptying, partly through the vagal pathway, in dogs. The aim of this study was to evaluate whether atropine-induced autonomic nervous alteration, measured by heart ...
Jovanov E - - 2005
Very slow yogic breathing techniques provide valuable insights into mechanisms of autonomous nervous system regulation that are usually not available for human subjects. This paper presents results of eight sessions of Nadi Shodhana Pranayama practiced at rate of one breath per minute. We characterized statistic and spectral measures of heart ...
Kleiger Robert E - - 2005
Electrocardiographic RR intervals fluctuate cyclically, modulated by ventilation, baroreflexes, and other genetic and environmental factors that are mediated through the autonomic nervous system. Short term electrocardiographic recordings (5 to 15 minutes), made under controlled conditions, e.g., lying supine or standing or tilted upright can elucidate physiologic, pharmacologic, or pathologic changes ...
Biłan Andrzej - - 2005
Circadian variation of QT interval dispersion (QTd) and heart rate variability spectral indices was evaluated in healthy persons in 24-hour 3-lead electrocardiogram. Mean values, SD, and SD/mean were evaluated for 24 hours, each hour separately and in night, day, and morning periods. Table Curve 2D and multiple regression were applied ...
Kingsley M - - 2005
Ambulatory heart rate monitors and clinical electrocardiographic (ECG) devices are capable of measuring the length of consecutive cardiac periods (RR intervals). The aim of the study was to assess the agreement between the Polar 810s heart rate monitor (Polar) and the Reynolds digital ambulatory ECG using Pathfinder software version 8.4 ...
Li Xia - - 2005
The purpose of this paper is to study the method to assess function status of cardiovascular system effectively in order to guide prevention and protection. In this study an exercise testing was performed in two groups. 60 elder hypertensives were chosen as a group at relative worse healthy status, and ...
Himi Naoyuki - - 2004
Prodromal signs such as cardiac rhythm disturbance and changes in gastric motility are generally induced before and during nausea in humans. These autonomic reactions were compared in subjects who were or were not experiencing nausea. Nausea was induced by having the subjects view a movie of oscillating pictures. Seventeen healthy ...
Bartels Matthew N - - 2004
Heart rate variability (HRV) and systolic blood pressure variability (BPV) during incremental exercise at 50, 75, and 100% of previously determined ventilatory threshold (VT) were compared to that of resting controlled breathing (CB) in 12 healthy subjects. CB was matched with exercise-associated respiratory rate, tidal volume, and end-tidal CO(2) for ...
Ansorge Eric J - - 2005
We investigated the effect of muscle metaboreflex activation on left circumflex coronary blood flow (CBF), coronary vascular conductance (CVC), and regional left ventricular performance in conscious, chronically instrumented dogs during treadmill exercise before and after the induction of heart failure (HF). In control experiments, muscle metaboreflex activation during mild exercise ...
Middlekauff Holly R - - 2004
Prior work in animals suggests that muscle mechanoreceptor control of sympathetic activation (MSNA) during exercise in heart failure (HF) is heightened and that muscle mechanoreceptors are sensitized by metabolic by-products. We sought to determine whether 1) muscle mechanoreceptor control of MSNA is enhanced in HF patients and 2) lactic acid ...
Kaya Dayimi - - 2004
AIMS: B2-agonists and anticholinergic drugs may alter cardiac autonomic modulation. The aim of this study was to investigate the effects of inhaled salbutamol and ipratropium bromide on heart rate variability (HRV). METHODS AND RESULTS: A randomized, double-blind, crossover design study was conducted on 13 healthy volunteers. Salbutamol, ipratropium or placebo ...
Monahan Kevin D - - 2005
Animal studies suggest that prostanoids (i.e., such as prostacyclin) may sensitize or impair baroreceptor and/or baroreflex responsiveness depending on the site of administration and/or inhibition. We tested the hypothesis that acute inhibition of cyclooxygenase (COX), the rate-limiting enzyme in prostanoid synthesis, impairs baroreflex regulation of cardiac period (R-R interval) and ...
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