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Results 201 - 250 of 1782
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Martinez Jose M - - 2010
OBJECTIVE: To test the hypothesis that panic disorder (PD) patients have a heightened or deregulated autonomic nervous system at rest and during autonomic challenge compared with healthy controls (HC); and to test a second hypothesis that severity of illness differentiates patients'; sympathovagal balance both at rest and during orthostatic challenge. ...
Hagensen Mette K - - 2010
It has been suggested that ectothermic vertebrates primarily control blood pressure to protect the pulmonary vasculature from oedema caused by high pressure, while endothermic vertebrates control blood pressure to maintain adequate oxygen delivery to the tissues. In the present study we have characterised how temperature affects the cardiac limb of ...
Volpe Massimo - - 2010
The unique pathophysiology of heart failure with a preserved ejection fraction (HF-PEF) and the involvement of hypertension in its development are only poorly understood. The upregulation of the renin-angiotensin-aldosterone system (RAAS) has been identified as a key pathologic pathway contributing to fibrosis, cardiomyocyte abnormalities, inflammation, and endothelial dysfunction, all of ...
Agiovlasitis Stamatis - - 2010
This study examined whether the autonomic response to passive upright tilt as evidenced by changes in measures of heart rate and blood pressure variability differs between individuals with DS and without DS. Beat-to-beat blood pressure was measured in 26 individuals with Down syndrome (DS) and 11 individuals without DS during ...
Vanderheyden Marc - - 2010
BACKGROUND: Hemodynamic monitoring using implantable devices may provide early warning of volume overload in patients with heart failure (HF). This study was designed to prospectively compare information from intrathoracic impedance monitoring and continuous right ventricular pressure measurements in patients with HF. METHODS AND RESULTS: Sixteen patients with HF (age, 63.5+/-13.8 ...
Balueva T V - - 2010
In experiments on rats, changes in blood pressure and cardiac output in response to antiorthostatic (head-down) tilt 15° and 45° were examined under conditions of decreased arterial tone induced by sodium nitroprusside. The decrease in initial systemic blood pressure to 90 mm Hg attenuated the pressor responses to antiorthostasis, while ...
Nolan Robert P RP Division of Cardiology, Faculty of Medicine, University Health Network, University of Toronto, Toronto, Ontario, Canada. - - 2010
It is not established whether behavioral interventions add benefit to pharmacological therapy for hypertension. We hypothesized that behavioral neurocardiac training (BNT) with heart rate variability biofeedback would reduce blood pressure further by modifying vagal heart rate modulation during reactivity and recovery from standardized cognitive tasks ("mental stress"). This randomized, controlled ...
Demestiha Theano D - - 2010
Although approximately one million sudden cardiac deaths occur yearly in the US and Europe, cardiac arrest (CA) remains a clinical condition still characterized by a poor prognosis. In an effort to improve the cardiopulmonary resuscitation (CPR) technique, the 2005 American Heart Association (AHA) Guidelines for CPR gave the impedance threshold ...
Nieminen T - - 2010
All the commonly used definitions of baroreflex sensitivity (BRS) are based on a slope of linear relationship between systolic blood pressure and pulse interval (R-R interval). However, heart rate (HR) and R-R interval bear an inverse non-linear relationship, which distorts determination of BRS when different HR levels are present. We ...
Corino Valentina D A - - 2010
Atrial fibrillation (AF) is characterized by desynchronization of atrial electrical activity causing a consequent irregular ventricular response. In AF, the beat-to-beat variation of blood pressure is increased because of variations in filling time and contractility. However, only a few studies have analyzed short-term blood pressure variations in AF, and we ...
Chow Eric Y - - 2010
This paper presents a fully wireless cardiac pressure sensing system. Food and Drug Administration (FDA) approved medical stents are explored as radiating structures to support simultaneous transcutaneous wireless telemetry and powering. An application-specific integrated circuit (ASIC), designed and fabricated using the Texas Instruments 130-nm CMOS process, enables wireless telemetry, remote ...
Eckberg Dwain L - - 2010
Although astronauts' cardiovascular function is normal while they are in space, many have altered haemodynamic responses to standing after they return to Earth, including inordinate tachycardia, orthostatic hypotension, and uncommonly, syncope. Simulated microgravity impairs vagal baroreceptor-cardiac reflex function and causes orthostatic hypotension. Actual microgravity, however, has been shown to either ...
Kutluk Abdugheni - - 2010
This paper proposes a new method of evaluating autonomic nervous activity using the mechanical impedance of arterial walls and heart rate variability. The cardiovascular system is indispensable to life maintenance functions, and homeostasis is maintained by the autonomic nervous system. Accordingly, it is very important to be able to make ...
Sapoznikov Dan - - 2010
OBJECTIVES: The role of the baroreflex function in the pathogenesis of hemodialysis-associated hypotension is controversial. Complex demodulation technique (CDM), providing continuous assessment of the amplitude of cardiovascular oscillation over time, is particularly suitable to assess dynamic changes in autonomic nervous system and baroreceptor sensitivity (BRS) during dialysis. In the present ...
Finucane Ciar?n - - 2010
AIMS: Mayer waves are low frequency blood pressure waves, whose modulation involves central/peripheral baroreflex pathways. Although vasodepressor carotid sinus hypersensitivity (VDCSH) is a common hypotensive disorder in ageing, the mechanism of VDCSH is unknown. We hypothesize that VDCSH is due to impaired baroreflex function and that Mayer wave amplitude and ...
Gmitrov Juraj - - 2010
PURPOSE: We compared the effect of static magnetic field (SMF) and verapamil, a potent vascular calcium channel blocking agent, on sudden elevation in blood pressure in conjunction with arterial baroreflex sensitivity (BRS) and microcirculation. MATERIALS AND METHODS: Forty-four experiments were performed on conscious rabbits sedated using pentobarbital intravenous (i.v.) infusion ...
Oka Hisayoshi - - 2010
Several studies have reported that olfactory dysfunction is an early neuropathological manifestation of Parkinson's disease (PD). Reduced cardiac meta-iodobenzylguanidine ((123)I-MIBG) uptake may be one of the earliest signs of PD. We studied the relation of olfactory dysfunction to cardiovascular dysautonomia in patients with PD. The study group comprised 66 patients ...
Goldstein David S - - 2010
Olfactory dysfunction and autonomic failure are gaining recognition as nonmotor manifestations of Parkinson disease (PD). This observational study assessed whether in PD anosmia and autonomic failure are related to each other or to neuroimaging evidence of striatal dopamine deficiency. Olfactory function was assessed by the University of Pennsylvania Smell Identification ...
Verheyden B - - 2010
Entering weightlessness affects central circulation in humans by enhancing venous return and cardiac output. We tested whether the operational point of neural cardiovascular regulation in space sets accordingly to adopt a level close to that found in the ground-based horizontal position. Heart rate (HR), finger blood and brachial blood pressure ...
Weber Cora Stefanie - - 2010
Reduced heart rate variability (HRV) and delayed blood pressure recovery are associated with increased cardiovascular risk. Besides this evident link, the vagus is thought to play an inhibitory role in the regulation of other allostatic systems, including inflammation and the hypothalamic-pituitary-adrenal (HPA) axis. However, human evidence is scarce. To further ...
Maines Massimiliano - - 2010
AIMS: The aims of this analysis were to assess the agreement between implantable defibrillator (ICD)-measured intrathoracic impedance and pulmonary capillary wedge pressure (PCWP) collected during long-term follow-up, as well as to evaluate whether PCWP measures may improve the performance of the impedance detection algorithm in predicting heart failure (HF) worsening. ...
Orini Michele - - 2010
In this study we propose a method to continuously assess the changes of spontaneous baroreflex sensitivity (BRS). Systolic arterial pressure and RR intervals are analyzed by time-frequency analysis to estimate their instantaneous powers as well as the time-course of their spectral coherence. The BRS estimated in classical frequency bands is ...
Carpenter Rosann J - - 2010
Restoration of the sympathovagal (S/V) balance, involving a lowering of sympathetic and/or an augmentation of vagal modulation or a combination of both is associated with improvements in cardiovascular morbidity and mortality. To determine whether acupuncture exerts a favorable influence upon resting blood pressure and sympathovagal balance, a single-blind cross-over investigation ...
Iqbal P - - 2010
Introduction. 24-hour ambulatory blood pressure monitoring (ABPM) plays an important role in assessing cardiovascular prognosis, through presence or absence of ABPM-related prognostic features. Objectives. To study relationship between 24-hour ABPM and cardiovascular outcomes in patients from Chesterfield Royal Hospital. Material and Methods. Over 12 months from the 1st of August ...
Jíra M - - 2010
Increased blood pressure variability (BPV) and decreased inter-beat interval (heart rate, respectively) variability (IBIV, HRV respectively) are associated with cardiovascular disorders. The aim of this study was to evaluate the reproducibility of BPV and IBIV (HRV) in young healthy individuals. Blood pressure and inter-beat intervals (instantaneous values of heart rate, ...
Porta A - - 2010
This study assesses the information transfer through the spontaneous baroreflex (i.e. through the pathway linking systolic arterial pressure to heart period) during an experimental condition soliciting baroreflex (i.e. head-up tilt). The information transfer was calculated as the conditional entropy of heart period given systolic arterial pressure using a mutual neighbor ...
Sakamoto Takafumi - - 2010
Baroreflex regulates arterial pressure by modulating ventricular and vascular properties. We investigated if the framework of circulatory equilibrium that we developed previously (Am J Physiol 2004, 2005) by extending the classic Guyton's framework is capable of predicting baroreflex induced changes in arterial pressure. In animal experiments, we estimated open loop ...
Sunagawa Kenji - - 2010
The baroreflex system is the fastest mechanism in the body to regulate arterial pressure. Because the neural system (i.e., autonomic nervous system) mediates the baroreflex and the system operates under the closed-loop condition, the quantitative dynamic characteristics of the baroreflex system remained unknown until recently despite the fact that a ...
Heijmans J H - - 2010
Central venous pressure (CVP) and pulmonary capillary wedge pressure (PCWP) are insensitive preload markers and sometimes misleading. The introduction of the pulse contour method for monitoring of continuous cardiac output enabled the real-time quantification of stroke volume variation (SVV). Studies evaluating the accuracy of this parameter as a measure of ...
Hongratanaworakit Tapanee - - 2010
The aim of this study was to investigate the effect of aromatherapy massage with jasmine oil (Jasminum sambac L., Oleaceae) on humans. Human autonomic parameters, i.e. blood pressure, pulse rate, blood oxygen saturation, breathing rate, and skin temperature, were recorded as indicators of the arousal level of the autonomic nervous ...
Bennett Stephen N - - 2010
Hybridization and introgression between introduced and native salmonids threaten the continued persistence of many inland cutthroat trout species. Environmental models have been developed to predict the spread of introgression, but few studies have assessed the role of propagule pressure. We used an extensive set of fish Stocking records and geographic ...
Van de Louw Andry - - 2010
Baroreflex allows to reduce sudden rises or falls of arterial pressure through parallel RR interval fluctuations induced by autonomic nervous system. During spontaneous breathing, the application of positive end-expiratory pressure (PEEP) may affect the autonomic nervous system, as suggested by changes in baroreflex efficiency and RR variability. During mechanical ventilation, ...
Hsu Suh-Meei - - 2010
This study sought to study the associations of noise with heart rate, blood pressure, and perceived psychological and physiological responses among post-cardiac surgery patients in ICUs. Forty patients participated in this study after recovering from anesthesia. A sound-level meter was placed at bedsides to measure noise level for 42 hours, ...
Burns John W - - 2010
Investigation of resuscitation fluids in our swine hemorrhage model revealed moderate to severe chronic pneumonia in five swine at necropsy. Our veterinary staff suggested that we perform a retrospective analysis of prospectively collected data from these animals. We compared the data to that of ten healthy swine to determine the ...
Aletti Federico F Dipartimento di Bioingegneria, Politecnico di Milano, Piazza Leonardo da Vinci, 32, 20133, Milan, Italy. - - 2010
Arterial blood pressure (ABP) short term variability is due to beat-by-beat fluctuations in cardiac output (CO) and total peripheral resistance (TPR), which have distinct effects at low and high frequencies. In particular, it was shown that CO is able to buffer TPR slow oscillations in the LF band, but it ...
Percie du Sert Nathalie - - 2009
AIM: To characterize the gastric myoelectric activity (GMA) and intra-abdominal pressure changes induced by emetic stimuli (apomorphine and cisplatin) in the ferret. METHODS: GMA and intra-abdominal pressure were recorded in conscious, unrestrained ferrets surgically implanted with radiotelemetry transmitters. Animals were challenged with apomorphine (0.25 mg/kg sc) and cisplatin (10 mg/kg ...
Galetta Fabio F Department of Internal Medicine, University of Pisa, Via Roma, 67, 56126 Pisa, Italy. - - 2010
The aim of the study was to examine the effect of the antihypertensive AT1 receptors antagonist telmisartan on cardiovascular autonomic function and QT dispersion in hypertensive patients with LVH. Twenty-five patients (18 males and seven women, mean age 49.8±5.2 years) with mild essential arterial hypertension and LVH were compared with ...
Havlicekova Z - - 2009
Impairment in cardiovascular autonomic regulation participates in the onset and maintenance of primary hypertension. The aim of the present study was to evaluate cardiac autonomic control using long-term heart rate variability (HRV) analysis in adolescents with primary hypertension. Twenty two adolescent patients with primary hypertension (5 girls/17 boys) aged 14-19 ...
Meyer C - - 2009
Autonomic neuropathy is common in patients suffering from end-stage renal disease (ESRD). This may in part explain the high cardiovascular mortality in these patients. Chemosensory function is involved in autonomic cardiovascular control and is mechanistically linked to the sympathetic tone. The aim of the present study was to assess whether ...
Beloka S P - - 2009
In patients with hypertension, beta blockade decreases muscle sympathetic nerve activity (MSNA; micrographic technique) expressed in burst frequency (burst/min) but does not affect MSNA expressed in burst incidence (burst/100 heart beats), because reductions in blood pressure (BP) upon each diastole continue to deactivate the arterial baroreceptors, but at a slower ...
Guasti L - - 2010
The baroreflex control of circulation is always operating and modulates blood pressure and heart rate oscillations. Thus, the study of cardiovascular variability in humans is performed in a closed-loop model and the physiology of post-sinoaortic denervation is completely unknown in humans. We dissected for the first time the different components ...
Tobaldini Eleonora - - 2009
We validated a symbolic approach to assess autonomic modulation from pulse interval (PI) and systolic arterial pressure (SAP) series obtained from an animal model of chronic heart failure (CHF). We studied three groups of rats: controls; CHF animals; CHF animals treated with spironolactone (CHF-SP), reducing sympathetic activity in CHF. Simulations ...
Okano Yasuko Y Department of Medical Science and Cardiorenal Medicine, Yokoham City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-Ku, Yokohama City, Japan. - - 2009
The aim of the present study was to examine the relationships between the anti-hypertensive effects, autonomic function, and health-related quality of life (HRQOL) following treatment of hypertensive subjects with angiotensin receptor blockers (ARBs) in hypertensives. Nineteen patients with hypertension were assigned randomly to daily treatment with ARBs. After 16 weeks ...
Pfurtscheller Gert - - 2010
Slow oscillations around 0.1 Hz are characteristic features of both the cardiovascular and central nervous systems. Such oscillation have been reported, e.g. in blood pressure, heart rate, EEG and brain oxygenation. Hence, conscious intention of a motor act may occur only as a result of brain activity changes in frontal ...
Koseoglu Emel - - 2009
The aim of this study was to evaluate possible factors affecting interictal cardiovascular autonomic function in temporal lobe epilepsy with complex partial seizures, paying special attention to hippocampal sclerosis. The study was carried out with 88 patients with epilepsy (22 with left hippocampal sclerosis, 22 with right hippocampal sclerosis, and ...
Harrison Joanne L - - 2010
Autonomic dysfunction, hypertension and cardiovascular morbidity in end stage renal disease are critically linked, however there are limited models available to investigate this relationship and develop clinical interventions. This study aimed to define the relationship between hypertension and autonomic function in a new rodent model of polycystic kidney disease (PKD). ...
Lucini Daniela - - 2009
To focus on early cardiac and vascular autonomic dysfunction that might complicate type 1 diabetes mellitus in children, we planned an observational, cross-sectional study in a population of 93 young patients, under insulin treatment, subdivided in 2 age subgroups (children: 11.5+/-0.4 years; adolescents: 19.3+/-0.2 years). Time and frequency domain analysis ...
Masuki Shizue - - 2009
We assessed whether increased cerebral activity suppressed baroreflex control of heart rate (HR) and, if so, whether this occurred prior to the onset of locomotion in daily activity of mice. We measured mean arterial pressure (MAP, arterial catheter), cerebral blood flow in the motor cortex (CBF, laser-Doppler flowmetry), and electroencephalogram ...
Taneyama Chikuni - - 2009
BACKGROUND: It has been shown that stellate ganglion block can attenuate baroreflex sensitivity. Our primary purpose in this study was to determine whether fractal dynamics (dynamic change of self-similar fluctuation patterns) of not only heart rate but also systolic blood pressure variability are involved in attenuation of baroreflex sensitivity after ...
Pavithran Purushothaman - - 2010
1. Abnormalities of cardiac autonomic regulation are a potential mechanism for morbidity despite blood pressure (BP) lowering in hypertension. Analysis of short-term (5 min) heart rate variability (HRV) provides a non-invasive probe of autonomic regulation of sino-atrial (SA) node automaticity. 2. We hypothesized that antihypertensive drug therapy would be associated ...
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